Archive for the ‘HDI PCB’ Category

Wednesday, October 23rd, 2024

The core thickness range of HDI PCB (High Density Interconnect Circuit Board) mainly depends on its design and application requirements. According to different processes and application scenarios, the core thickness of HDI PCB can vary from 0.6mm to 1.0mm.

What is the standard thickness of a PCB core?

The standard thickness of PCB core boards usually includes the following specifications: 0.5mm, 0.7mm, 0.8mm, 1.0mm, 1.2mm, 1.5mm, 1.6mm, 2.0mm, 2.4mm, 3.2mm, 6.4mm. These thickness specifications are widely used in different electronic products and circuit board designs.

The thickness of PCB includes not only the thickness of the core board, but also the total thickness of all layers such as copper layer, solder mask layer and silk screen. The standard thickness ranges widely, from thinner 0.5mm to thicker 6.4mm, suitable for different application requirements.

Choosing the right PCB thickness is essential to ensure the performance and reliability of the circuit board. Thicker PCBs have higher mechanical strength and load-bearing capacity, and are suitable for products with high power and large electronic components, such as industrial, automotive, aerospace and military applications.

Ultra-thin PCBs are suitable for small electronic products such as smartphones, smart wearable devices and laptops due to their lightweight characteristics.

What is the thickness tolerance of a PCB core?

The thickness tolerance of a PCB core varies according to different thickness ranges.

For PCBs with a thickness of less than or equal to 1mm, the board thickness tolerance is ±10% of the board thickness. For example, a PCB with a thickness of 0.5mm has a tolerance of ±0.05mm; a PCB with a thickness of 0.8mm has a tolerance of ±0.08mm.

For PCBs with a thickness greater than 1mm and less than or equal to 1.6mm, the tolerance is ±0.14mm.

For PCBs with a thickness greater than 1.6mm and less than or equal to 2.0mm, the tolerance is ±0.18mm.

For PCBs with a thickness greater than 2.0mm and less than or equal to 2.4mm, the tolerance is ±0.22mm.

For PCBs with a thickness greater than 2.4mm and less than or equal to 3.0mm, the tolerance is ±0.25mm.

For PCBs with a thickness greater than 3.0mm, the tolerance is ±10%.

These tolerance standards apply to most PCB manufacturing processes, ensuring the stability and reliability of the PCB.

What is the difference between HDI and non-HDI PCB?

The main differences between HDI PCB and non-HDI PCB are their line density, size, production process and electrical performance. HDI PCB (High Density Interconnect PCB) has higher line density, smaller size and better electrical performance, while ordinary PCBs are lacking in these aspects.

First of all, the design and structure of HDI PCB are significantly different from ordinary PCBs. HDI PCB adopts higher line density and more complex circuit layout, which enables smaller size and lighter design. In contrast, ordinary PCBs have lower line density and are suitable for some application scenarios that do not require high line density.

In terms of production process, the manufacturing process of HDI PCB is relatively complex, including laser drilling, stacked copper plates, etching technology, etc., to achieve high-density interconnection and complex circuit wiring. The manufacturing process of ordinary PCB is relatively simple, generally using photolithography, etching process, etc.

In terms of electrical performance, HDI PCB uses technologies such as blind holes and buried holes to reduce signal transmission paths and improve the transmission rate and stability of electrical signals. In addition, HDI PCB also has better radio frequency interference, electromagnetic wave interference, electrostatic discharge and thermal conductivity performance.

Finally, the cost of HDI PCB is relatively high, mainly due to its complex manufacturing process and high technical requirements. The manufacturing cost of ordinary PCB is low, which is suitable for some application scenarios with low requirements for line density and technology.

How thick is a 2 layer PCB core?

The thickness of a 2-layer PCB core is usually 0.4mm.

PCB core is a base material composed of copper foil, solid resin material and glass fiber, with a certain hardness and thickness. Common PCB core thickness specifications include 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 1.0mm, 1.2mm, 1.5mm, 1.6mm, 2.0mm, 2.4mm, etc.

Among the common specifications of Shengyi core boards, the thickness of 0.4mm is widely used. In addition, the performance of multi-layer PCBs does not directly depend on the number of layers, but more reflects the space requirements during design.

Are HDI PCB reliable?

HDI PCBs are reliable. HDI PCBs are manufactured using high-density and high-reliability interconnection technology, with higher line density and more complex circuit layout, which can achieve smaller and lighter electronic devices.

Compared with ordinary PCBs, HDI PCBs perform well in anti-interference ability and electromagnetic compatibility, and can effectively reduce the impact of external interference on signal transmission, while having higher reliability and longer service life.

The reliability of HDI PCBs is due to the high-quality substrates, solder mask and copper foil materials used, as well as strict manufacturing processes and quality control. These characteristics enable HDI PCBs to maintain stable performance and quality in various harsh environments.

In addition, the development trend of HDI PCBs is towards higher integration, higher signal transmission rate, better electromagnetic compatibility and optimized thermal management capabilities, which further enhances its application value in high-performance and high-density integration requirements.

What are the benefits of HDI PCB?

The main benefits of HDI PCB include high-density wiring, high-performance signal transmission, adaptability to high-frequency applications, miniaturization, and thinness. These characteristics make HDI PCB play a vital role in electronic devices, especially in high-end electronic products such as smartphones, tablets, and high-end computers.

First, HDI PCB has the characteristics of high-density wiring, which can achieve more circuit connections in a smaller space. This allows the design of electronic products to be more compact and meet application scenarios with extremely high space requirements.

Secondly, HDI PCB excels in high-performance signal transmission, can provide better signal transmission quality and electrical performance, and is particularly suitable for processing high-speed and high-frequency signals.

In addition, HDI PCB also has the advantages of miniaturization and thinness, which contributes to the thinness and miniaturization of electronic products, making the equipment more portable while maintaining high performance.

These benefits of HDI PCB are due to its advanced manufacturing process and technology. By adopting finer line widths and smaller apertures, HDI PCB achieves higher wiring density and signal transmission speed.

At the same time, by optimizing material selection and circuit design, HDI PCB can reduce the loss and reflection during signal transmission and improve the integrity and accuracy of the signal. In addition, HDI PCB also has better anti-interference ability and electromagnetic compatibility, which can effectively reduce the impact of external interference on signal transmission.

The application range of HDI PCB is very wide, including smart phones, tablets, laptops, medical equipment and communication equipment. Due to its high-density interconnection and excellent electrical performance, HDI PCB plays an important role in these fields, promoting the development of the PCB industry, so that more dense components can be arranged more closely on HDI boards.

What are the disadvantages of HDI PCB?

The main disadvantages of HDI PCB include high cost, complex production process, environmental sensitivity and possible quality problems.

First, the cost of HDI PCB is relatively high. This is because high-precision manufacturing technology and special materials are required in its manufacturing process, which all lead to its cost increase.

In addition, HDI PCB is usually used in high-performance equipment, and the value of these equipment itself is also high, which further pushes up the price of HDI PCB.

Second, the production process of HDI PCB is very complicated. Due to its high density of lines and components, the manufacturing of HDI PCB requires highly precise processes and equipment. This not only increases the difficulty of production, but may also lead to a longer production cycle, further increasing costs.

In addition, HDI PCB has certain requirements for the environment. Due to its delicate structure, HDI PCB is very sensitive to humidity and temperature changes in the environment. Improper storage or transportation conditions may cause the PCB to become damp or deformed, affecting its performance and reliability.

Finally, HDI PCB may have some quality problems. Due to the complexity of the production process, HDI PCB may have problems such as poor solderability, delamination, short circuit, open circuit, etc. These problems may need to be avoided through strict quality control and testing.

The core thickness of HDI PCB is an important parameter, which is directly related to the performance and application of PCB. When choosing the core thickness of HDI PCB, factors such as application requirements, design requirements and manufacturing process need to be considered comprehensively to select the appropriate core thickness.

Is the circuit board DC or AC?

Circuit boards can transmit both direct current and alternating current. In modern electronic products, we use alternating current for power supply, so most circuit boards are also designed to transmit alternating current. Of course, in some special application scenarios, some circuit boards also need to transmit direct current. Whether transmitting direct current or alternating current, the circuit board needs to meet the requirements of the transmitted current.

What is the PCB in AC?

The alternating current in PCB refers to the current whose direction changes periodically, that is, alternating current (AC). The application of alternating current in PCB is mainly reflected in power conversion and power transmission. PCB power supply usually converts AC into stable direct current (DC) output to meet the demand of electronic equipment for stable power supply. PCB power supply converts AC into the required DC through components such as transformers, rectifiers, filters and voltage regulators, and provides stable power output.

How to calculate the bandwidth of AC in PCB traces

The calculation of AC PCB trace width can be performed by the following formula: W = (I / J) * K, where W represents the trace width, I represents the current, J represents the current density, and K represents a coefficient related to materials and processes. ‌This formula shows that the trace width is related to the current, current density, and material properties‌.

AC in PCB Design Guide

Current Carrying Capacity: The width of a trace directly affects its ability to handle current without exceeding temperature limits or causing excessive voltage drop.
‌Impedance Control: In high-frequency applications, maintaining controlled impedance is critical for signal integrity. Trace width, trace spacing, and dielectric properties affect the characteristic impedance of the transmission line.
‌Heat Dissipation: Adequate trace width helps to effectively dissipate heat, preventing thermal issues such as trace delamination or solder joint failure.
‌Voltage Drop: Narrower traces exhibit higher resistance, resulting in increased voltage drop along the length of the trace. By adjusting the trace width, the voltage drop can be minimized.
‌Manufacturability: The PCB manufacturing process imposes restrictions on the minimum trace width, and designers must balance performance requirements with manufacturability constraints. ‌2.
‌Minimum Trace Width: Most manufacturers have a minimum trace width of 6mil or 0.152mm, and typically use traces of 0.254-0.3mm.
‌Material and Process Deviations: Due to the possibility of material and process deviations in the actual PCB manufacturing process, a certain margin needs to be left when calculating the line width.
‌Signal Integrity Simulation‌: Perform signal integrity simulations to ensure impedance is controlled and signal degradation due to reflections, crosstalk, or transmission line effects is minimized‌

AC in PCB wiring

The current trend is that the power supply voltage is getting lower and lower (especially for highly integrated digital devices), the space occupied is getting smaller and smaller, the weight is getting lighter and lighter, and the efficiency is getting higher and higher, which requires the precise design of the power supply circuit starting from the PCB.

Safety distance includes electrical clearance (spatial distance), creepage distance (surface distance) and insulation penetration distance…

Electrical clearance: the shortest distance between two adjacent conductors or one conductor and the adjacent motor housing surface measured along the air.
Creepage distance: the shortest distance between two adjacent conductors or one conductor and the adjacent motor housing surface measured along the insulation surface.

Determination of electrical clearance:

The distance can be determined according to the measured working voltage and insulation level

The electrical clearance size requirements of the primary side line are shown in Table 3 and Table 4

The electrical clearance size requirements of the secondary side line are shown in Table 5

But usually: Primary side AC part: L-N ≥ 2.5mm before the fuse, L.N PE (earth) ≥ 2.5mm, no requirements are made after the fuse is installed, but a certain distance should be maintained as much as possible to avoid short circuit damage to the power supply.

Primary side AC to DC part ≥2.0mm

Primary side DC ground to earth ≥2.5mm (primary side floating ground to earth)

Primary side to secondary side ≥4.0mm, components connected between primary and secondary sides

Secondary side gap ≥0.5mm

Secondary side ground to earth ≥1.0mm

Note: Before determining whether it meets the requirements, the internal parts should be applied with a force of 10N and the outer shell with a force of 30N to reduce the distance so that the space distance still meets the requirements under the worst case.

Determination of creepage distance:

Based on the working voltage and insulation level, the creepage distance can be determined by looking up Table 6

But usually: (1), primary side AC part: L-N ≥2.5mm before the fuse, L.N earth ≥2.5mm, no requirement is required after the fuse, but try to keep a certain distance to avoid short circuit damage to the power supply.

(2) Primary side AC to DC part ≥2.0mm

(3) Primary side DC ground to ground ≥4.0mm such as primary side ground to earth

(4) Primary side to secondary side ≥6.4mm, such as optocoupler, Y capacitor and other components, the foot spacing ≤6.4mm needs to be slotted.

(5) Secondary side parts ≥0.5mm

(6) Secondary side ground to earth ≥2.0mm or more

(7) Transformer two-stage ≥8.0mm or more

Insulation penetration distance:

It should meet the following requirements according to the working voltage and insulation application:

For working voltage not exceeding 50V (71V AC peak or DC value), there is no thickness requirement;
The minimum thickness of additional insulation should be 0.4mm;
When the reinforced insulation is not subjected to any mechanical stress that may cause deformation or performance degradation of the insulating material at normal temperature, the minimum thickness of the reinforced insulation should be 0.4mm. If the insulation provided is used in the protective casing of the equipment and will not be bumped or scratched during maintenance by the operator, and any of the following conditions apply, the above requirements do not apply to thin insulating materials regardless of their thickness;
For additional insulation, at least two layers of material are used, each of which can pass the dielectric strength test for additional insulation; or:
For additional insulation composed of three layers of material, any combination of two layers of material can pass the dielectric strength test for additional insulation; or:
For reinforced insulation, at least two layers of material are used, each of which can pass the dielectric strength test for reinforced insulation; or:
For reinforced insulation composed of three layers of insulating material, any combination of two layers of material can pass the dielectric strength test for reinforced insulation.

Points to note about wiring process:

Flat components such as capacitors must be flat without glue.

If the distance between two conductors can be shortened by applying a force of 10N, which is less than the safety distance requirement, glue can be used to fix the part to ensure its electrical clearance.

When laying PVC film inside some shell equipment, attention should be paid to ensuring the safety distance (pay attention to the processing technology).

When fixing the parts with glue, be careful not to leave foreign matter such as glue wire on the PCB board.

When processing parts, insulation damage should not be caused.

Requirements for flame-proof materials:

Heat shrink tubing V-1 or VTM-2 or above; PVC tubing V-1 or VTM-2 or above

Teflon tubing V-1 or VTM-2 or above; plastic materials such as silicone sheets, insulating tape V-1 or VTM-2 or above

PCB board 94V-1 or above

Regarding insulation level

(1) Working insulation: insulation required for normal operation of equipment

(2) Basic insulation: insulation that provides basic protection against electric shock

(3) Supplementary insulation: independent insulation applied in addition to basic insulation to protect against electric shock in case of basic insulation failure

(4) Double insulation: insulation consisting of basic insulation plus supplementary insulation

(5) Reinforced insulation: a single insulation structure that provides the same level of protection against electric shock as double insulation under the conditions specified in this standard

The applicable situations of various insulation are as follows:

A. Operational insulation

a. Between parts with different voltages

b. Between ELV circuits (or SELV circuits) and grounded conductive parts.

B. Basic insulation

a. Between parts with dangerous voltages and grounded conductive parts;

b. Between SELV circuits with dangerous voltages and grounding-dependent;

c. Between the primary power conductor and the grounded shield or the core of the main power transformer;

d. As part of double insulation.

C. Supplementary insulation.

a. Generally speaking, between accessible conductive parts and parts that may carry dangerous voltages after basic insulation is damaged, such as:

Ⅰ. Between the surface of handles, knobs, handles or similar objects and their ungrounded axis.

Ⅱ. Between the metal casing of the second category equipment and the outer skin of the power cord passing through this casing.

Ⅲ. Between the ELV circuit and the ungrounded metal casing.

b. As part of double insulation

D. Double insulation

Double insulation Reinforced insulation

Generally speaking, between the primary circuit and

a. between accessible ungrounded conductive parts, or

b. between floating SELV circuits, or

c. between TNV circuits

Double insulation = basic insulation + supplementary insulation

Note: ELV circuit: extra low voltage circuit

Under normal working conditions, the AC peak value between conductors or between any conductors does not exceed 42.4V or the DC value does not exceed 60V.

SELV circuit: safety extra low voltage circuit.

A properly designed and protected secondary circuit so that under normal conditions or single fault conditions, the voltage between any two accessible parts, and between any accessible parts and the protective grounding terminal of the equipment (only for Class I equipment) will not exceed the safety value.

TNV: communication network voltage circuit

Under normal working conditions, the circuit carrying communication signals

Difference between direct current and alternating current

‌The main differences between DC and AC include direction and polarity, voltage change, current loss, transformer use, and application scenarios.

‌Direction and polarity:

DC: The direction of the current remains unchanged, and the electrons flow from the positive electrode to the negative electrode.

AC: The direction of the current changes periodically, and the electrons flow back and forth between the positive and negative electrodes. ‌
‌Voltage change:

DC: The voltage remains constant and does not change over time.

AC: The voltage magnitude and direction change periodically over time. For example, the mains is an AC with a sine waveform.

‌Current loss:

DC: Fault losses are relatively small.

AC: There is capacitive current, and there is capacitive current in the transmission line. ‌
‌Transformer use:

DC: The voltage cannot be changed using a transformer.

AC: The voltage can be changed using a transformer, which is suitable for boosting voltage to reduce losses during long-distance transportation.

‌Application scenarios:

DC: Suitable for low-voltage electrical appliances and occasions that require stable current.
‌Alternating current‌: Suitable for household and industrial use, using transformers to change voltage to suit different needs.‌

FAQ About AC in PCB

FAQ About AC in PCB

Q: The relationship between PCB current and line width. Is the current divided into AC or DC?
A: The relationship between PCB current and line width is not divided into AC or DC. In terms of the nature of the lines on the PCB, the lines are all made of copper materials, and both AC and DC can pass. However, how much current can pass depends on the cross-sectional area of the line on your PCB. That is, line width x thickness of the copper foil of the line. If the cross-sectional area of the line is small, only small current signals can pass, and if the cross-sectional area is large, large current signals can pass. This signal can be AC or DC.
Not just 1mm, any line width can pass DC or AC signals.

Q: There is a packaged device, and there are 2 pins in the device that need to be connected to the live wire and neutral wire of 220V AC respectively. So how to deal with this power line when drawing the PCB? Are there any size requirements for pads, wires, etc.? Are there any protective measures required? Is it not possible to directly add pads to connect to the pin pads of the device?
A: It is best to mill a groove between the neutral wire and the live wire, and choose the thickness of the wire according to the current. When the current is large, you can put a tin layer on the wire, and the pad should be slightly larger.

Q: The grounding of the PCB circuit board design is also the negative pole. What is the difference between the grounding here and the AC grounding?

A: The concept of the circuit board ground is somewhat different from that of the power supply system. The power supply system refers to the earth, that is, the terminal with the same potential as the earth.

The ground in the circuit board is just a common terminal of a potential, which can be positive or negative, depending on the needs of the designer. It’s just that everyone is used to and assumes that the negative pole is the common terminal, that is, the ground. The circuit board ground is not necessarily connected to the earth.

But it must be connected to the earth when EMI filtering is required.

Q: Should all GNDs on the PCB board be connected? There is a terminal (screw type) with two terminals marked as V1+ and V1- on the PCB schematic. Should V1- be connected to the power supply ground? But I used a multimeter to measure why V3- is not connected to other GNDs on the board?

So how do you connect the ground and 10V of the power supply to the V1+ and V1- ends of the terminal?

A: Not all ground wires on the board are connected together. The ground wires are divided into analog ground and digital ground, just like the ground wire in DC and the ground wire in AC cannot be connected together. That is to say, there is a ground wire that is specifically used for power supply, and there is a ground wire that is specifically used for signals (shielding signal interference). These two ground wires cannot be connected together.
In addition, you mentioned V1+ and V1-, and V1- should not be considered a ground wire. Generally, the signal represented by this method is a differential signal, that is, the V1 signal is differentially divided into V1+ and V1-, which can reduce external interference and transmit farther. Finally, V1+ and V1- are integrated into the V1 signal.
You need to figure out whether the V1+ and V1- of the terminal are used for power supply. If they are used for power supply, then V1+ is the positive pole. V1- is the negative pole. Since you didn’t show us the picture, you can’t just connect it randomly. The circuit board needs to connect not only power but also signals, depending on how your board is made.

What are high density interconnects?

High-density interconnect (HDI) is a printed circuit board (PCB) manufactured using higher-density wiring technology. Compared with traditional PCB, HDI board achieves miniaturization, lightweight and higher wiring density of circuit board through smaller aperture, finer line width/spacing and more layers of blind and buried hole technology to adapt to Electronic devices, especially mobile devices, require efficient space utilization and high-performance transmission.

The core of HDI technology lies in its high-density wiring design. By increasing the number of PCB layers, reducing wire width and spacing, and using micro-hole (such as laser drilling) processes, HDI technology significantly increases circuit complexity and wiring density. This technology is often used in electronic products such as smartphones, tablets, and smart wearable devices, meeting the needs of these devices for efficient space utilization and high-performance transmission.

What is the difference between PCB and HDI?

The main differences between PCB and HDI boards lie in wiring density, manufacturing process, size and cost. HDI boards use high-density interconnection technology, with higher wiring density and more complex circuit layouts, while ordinary PCBs are relatively simple and suitable for some application scenarios that do not require high line density.

There are significant differences between HDI boards and ordinary PCBs in terms of wiring density, manufacturing process, size and cost. HDI boards use high-density interconnection technology, with higher wiring density and more complex circuit designs, enabling smaller size and lighter design requirements. In comparison, the wiring density of ordinary PCB is low, which is suitable for some application scenarios that do not require high line density.

In terms of manufacturing process, HDI boards use more advanced manufacturing processes, including laser drilling, stacked copper plates and etching technology, to achieve high-density interconnection and complex circuit wiring. In comparison, the manufacturing process of ordinary PCBs is relatively simple, usually using photolithography and etching processes.

Because HDI boards have higher circuit density and complex circuit layouts, their size and thickness are usually smaller, making them suitable for applications that require compact packaging and space constraints. Ordinary PCBs do not have these restrictions and are suitable for more diverse application scenarios.

In terms of cost, since the manufacturing process of HDI boards is more complex and has higher technical requirements, its manufacturing cost is relatively high. In comparison, ordinary PCBs have lower manufacturing costs and are suitable for some application scenarios that do not have high circuit density and technical requirements.

What is the structure of HDI PCB?

The structure of HDI PCB mainly includes inner laminate, outer laminate, gaskets, blind and buried vias and other components. ‌

The inner laminate is the core part of the HDI circuit board. It is composed of multiple layers of conductive materials and insulating materials alternately stacked. It mainly realizes the transmission and control of circuit signals. The number of layers of the inner laminate can be very high. It uses microporous technology to achieve a high-density circuit layout and has excellent electrical performance and stability‌.

The outer laminate is located on the outside of the inner laminate and is also composed of multiple layers of conductive materials and insulating materials alternately stacked. Its main function is to protect the internal circuit from the influence of the external environment, such as humidity, temperature, mechanical stress, etc. The outer laminate can also provide additional grounding and shielding to improve circuit performance and reliability‌.

The gasket is an insulating material used to connect the inner laminate and the outer laminate. Its main function is to isolate the inner and outer laminates, prevent electrical interference, and provide certain mechanical support to ensure the stability of the circuit board.

A blind buried via is a non-penetrating through hole located inside the inner laminate. It is not directly connected to the outer laminate and mainly realizes the electrical connection between the inner laminates. Blind and buried vias do not penetrate the entire circuit board, which can effectively reduce the thickness and weight of the circuit board and improve the circuit board’s thermal resistance and mechanical stress resistance.

What are the advantages of HDI PCB?

The main advantages of HDI PCB include high-density interconnection, optimized wiring design, good signal transmission performance, high reliability and stability, smaller size and weight, and higher production efficiency. ‌

First, HDI PCB achieves higher line density by using higher-level packaging technology and smaller apertures. This means that under the same board size, HDI PCB can accommodate more electronic components and complex circuit designs, thereby improving the performance of the product. ‌

Second, the design of HDI PCB is more compact. Through multi-layer wiring and micro-via technology, the size and weight of the circuit board can be greatly reduced, adapting to the trend of modern electronic devices to pursue thinness and shortness.

Finally, the production process of HDI PCB is more efficient, and advanced technologies such as laser opening, thin film transformer, and cover packaging are used to achieve high-efficiency production.

What are the disadvantages of HDI PCB?

1. Difficulty in impedance control: The complexity of pattern transfer and electroplating processes increases production difficulty, which may lead to unstable impedance values.

2. Complex production cost control: The high-density circuit part of HDI PCB has a slow etching speed, which leads to excessive etching of isolation lines and increases production costs.

‌3. Environmental impact‌: During the electroplating and etching process, a large amount of copper ions enter the waste liquid, causing environmental pollution and difficulty in recycling.

4. High difficulty in design and manufacturing: HDI PCB is manufactured using micro-blind buried via technology and built-up method. The technical requirements are high and the process is complex, which increases the difficulty of design and manufacturing.

‌5. High material costs‌: The materials used in HDI PCB, such as PI and other high-performance materials, are more expensive, increasing manufacturing costs‌.

6. Quality issues: HDI PCB is prone to problems such as poor solderability and delamination during the manufacturing process. These problems may require higher process capabilities and quality control to avoid.

What are the applications of HDI PCB?

HDI PCB (High Density Interconnect PCB) can greatly reduce the size and weight without sacrificing performance by using microvias and tiny line widths and spacing, and is particularly suitable for portable electronic devices.

The main application areas of HDI PCB include:

‌Communication field‌: HDI PCB can achieve higher data transmission rates and lower energy consumption by increasing the number of tiny components.

‌Automotive Electronics‌: HDI PCB reduces product volume and production costs in the high integration of automotive electronic products, ensuring the stable operation of automotive electronic products.

‌Medical Equipment‌: HDI PCB is widely used in high-precision and high-stability medical equipment, improving the accuracy, sensitivity and stability of the equipment‌.

‌Mobile Communication‌: HDI PCB supports high-speed data transmission, maintains stable signal transmission, and supports a variety of wireless communication technologies‌.

‌High Performance Computing (HPC)‌: HDI PCB provides efficient interconnection channels, significantly improving computing performance and response speed‌.

In short, high-density interconnection circuit boards, as an important embodiment of high-density interconnection technology, play an irreplaceable role in the development of modern electronic technology. With the continuous advancement of technology, its future development prospects are still very broad, and it will continue to promote the development of electronic devices in the direction of smaller, stronger, and smarter.

What are the holes in a PCB called?

What are the holes on PCB called? What are the holes in the circuit? The holes on PCB can be roughly divided into 3 types, screw holes (mounting holes), conductive holes (vias), and plug-in holes.

Screw holes: Screw holes are used for fixing.

Conductive holes: Conductive holes (also called vias) are used for conducting electricity just like circuits.

Plug-in holes: Plug-in holes are of course used to plug in various parts, such as diodes, transistors, capacitors, inductors, etc.

What is a through hole

What is a through hole? Through holes, also known as perforations, are holes in a PCB that go all the way through the board. Their main purpose is to provide electrical connections for component pins while allowing soldering on both sides of the board.

1.A via is a special through hole whose wall is metallized to achieve electrical connection between different layers on a circuit board. This type of hole is usually used to connect component pins to internal circuits, or to achieve electrical connection between different layers in a multi-layer PCB. Vias need to be metallized during the PCB manufacturing process, which usually includes drilling, desmearing, chemical copper plating, and electroplating.

2.Non-conducting holes are the opposite of through holes. Their hole walls are not metallized, so they do not have electrical connection functions. These holes are mainly used for mechanical fixation, heat dissipation or identification purposes. Non-conducting holes are relatively simple in the PCB manufacturing process, and only drilling operations are required.

What is a blind via?

A blind via is a hole that extends from one side of a PCB to a certain internal layer without penetrating the entire board. The emergence of blind vias is mainly due to the development of HDI technology, which provides circuit designers with greater flexibility and more compact layout. Blind vias are usually used to connect surface mount components (SMD) to internal circuit layers, or to connect circuits between different internal layers.

What are buried vias?

Buried vias are holes located inside the PCB that do not penetrate any side of the board. They are completely hidden inside the board and are used to connect circuits between different internal layers. Buried vias are especially useful in HDI boards because they can reduce the overall thickness of the board while maintaining electrical connections between internal circuits.

What is a microvia?

Microvia refers to a hole with a smaller diameter, usually at the micron level. The emergence of microvia technology enables PCB designers to achieve more complex circuit layouts in a smaller space. Microvias are often used in high-density, high-reliability electronic devices such as mobile phones and tablets. The manufacture of microvias requires high-precision drilling equipment and technology to ensure the accuracy and reliability of the holes.

What are Mounting holes？

What are Mounting holes?Locking holes are auxiliary holes used in the PCB manufacturing and assembly process to accurately locate and fix the circuit board. They are usually located at the edge or specific position of the PCB to ensure that the circuit board can be accurately aligned and fixed during manufacturing, testing and assembly. The locating holes do not participate in the connection of the circuit, but are essential to ensure the quality and performance of the circuit board.

What are Mounting holes？

What are thermal vias?

Thermal vias are holes designed specifically for heat dissipation, usually large and can run through the entire PCB or multiple layers. Their role is to reduce heat buildup on the circuit board by increasing surface area and air flow, thereby improving the stability and reliability of the device. Thermal vias are particularly important in high-performance, high-power electronic devices.

FAQ About board electronics with holes

How to solve the contradiction between manual routing and automatic routing of high-speed signals?

Most of the current powerful routing software’s automatic routing tools have set constraints to control the routing method and the number of vias. The routing engine capabilities and constraint setting items of various EDA companies are sometimes very different. For example, whether there are enough constraints to control the winding method of the serpentine, whether the routing spacing of the differential pair can be controlled, etc. This will affect whether the routing method generated by automatic routing can meet the designer’s ideas. In addition, the difficulty of manually adjusting the routing is also related to the capabilities of the routing engine. For example, the pushing ability of the routing, the pushing ability of the via, and even the pushing ability of the routing pair copper. Therefore, choosing a routing tool with strong routing engine capabilities is the solution.

Will adding test points affect the quality of high-speed signals?

As for whether it will affect the signal quality, it depends on the method of adding test points and how fast the signal is. Basically, the additional test points (not using the existing vias (via or DIP pins) as test points) may be added to the line or a small section of wire may be pulled out from the line. The former is equivalent to adding a very small capacitor to the line, while the latter is an additional branch. Both of these situations will have some impact on high-speed signals, and the extent of the impact is related to the frequency speed of the signal and the edge rate of the signal. The magnitude of the impact can be learned through simulation. In principle, the smaller the test point, the better (of course, it must meet the requirements of the test equipment) and the shorter the branch, the better.

Can you introduce some foreign technical books and data on high-speed PCB design?

Now the application of high-speed digital circuits includes communication networks and calculators and other related fields. In the communication network, the operating frequency of PCB boards has reached around GHz, and the number of layers is as many as 40 layers as far as I know. Due to the advancement of chips, the operating frequency of calculator-related applications, whether it is a general PC or server, has reached 400MHz (such as Rambus) or above. In response to the demand for high-speed and high-density routing, the demand for blind/buried vias, mircrovias and build-up process technology is gradually increasing. These design requirements can be mass-produced by manufacturers.

Does the design of rigid-flexible boards require special design software and specifications? Where can I undertake the processing of such circuit boards in China?

Can I use general PCB design software to design flexible printed circuits (Flexible Printed Circuit). The Gerber format is also used for FPC manufacturers to produce. Since the manufacturing process is different from that of general PCBs, each manufacturer will have its own restrictions on line width, line spacing, and aperture (via) based on their manufacturing capabilities. In addition, some copper foil can be laid at the turning point of the flexible circuit board for reinforcement. As for the manufacturer, you can search for “FPC” as a keyword on the Internet and you should be able to find it.

If the size of the circuit board is fixed, if the design needs to accommodate more functions, it is often necessary to increase the routing density of the PCB, but this may lead to increased mutual interference between the routings, and at the same time, the impedance cannot be reduced if the routing is too thin. Please introduce the techniques in the design of high-speed (>100MHz) high-density PCBs?

When designing high-speed and high-density PCBs, crosstalk interference does need to be paid special attention to because it has a great impact on timing and signal integrity. Here are a few things to note:

Control the continuity and matching of the characteristic impedance of the trace.

The size of the trace spacing. The spacing commonly seen is twice the line width. Through simulation, you can know the impact of trace spacing on timing and signal integrity and find the tolerable spacing. The results of different chip signals may be different.

Choose an appropriate termination method.

Avoid the same routing direction of the upper and lower adjacent layers, or even have traces overlapped up and down, because this kind of crosstalk is greater than the case of adjacent traces on the same layer.

Use blind/buried vias to increase the trace area. However, the production cost of the PCB board will increase. It is indeed difficult to achieve complete parallelism and equal length in actual implementation, but it should be done as much as possible.

In addition, differential termination and common mode termination can be reserved to mitigate the impact on timing and signal integrity.

The RF part, IF part, and even the low-frequency circuit part of the outdoor unit are often deployed on the same PCB. What are the material requirements for such PCB? How to prevent interference between RF, IF, and even low-frequency circuits?

Hybrid circuit design is a big problem. It is difficult to have a perfect solution.

Generally, RF circuits are laid out and wired as an independent single board in the system, and there will even be a special shielding cavity. Moreover, RF circuits are generally single-sided or double-sided boards, and the circuits are relatively simple. All of these are to reduce the impact on the distributed parameters of RF circuits and improve the consistency of RF systems. Compared with general FR4 materials, RF circuit boards tend to use high-Q substrates. The dielectric constant of this material is relatively small, the distributed capacitance of the transmission line is small, the impedance is high, and the signal transmission delay is small. In hybrid circuit design, although RF and digital circuits are made on the same PCB, they are generally divided into RF circuit area and digital circuit area, and laid out and wired separately. Shielding is used between ground vias and shielding boxes.

‌What is a high frequency pcb communication circuits

High frequency pcb communication circuits to a circuit board with an operating frequency in the high frequency band (usually greater than 300MHz or a wavelength less than 1 meter), which is mainly used to transmit high-frequency signals and data. ‌ This type of circuit board is widely used in radio frequency (RF) and microwave fields, such as communication equipment, radar systems, satellite communications, and high-speed data transmission systems.

What is a high frequency pcb communication circuits

The characteristics of high-frequency circuits include challenges such as transmission line effects, signal integrity issues, and electromagnetic interference (EMI). Due to the short wavelength of high-frequency signals, traditional low-frequency circuit design methods are no longer applicable, and special design and processing methods are required to ensure the performance and stability of the circuit.

High-frequency circuit boards are produced on microwave substrate copper-clad boards using ordinary rigid circuit board manufacturing methods or special processing methods. They need to have high-quality electrical properties and chemical stability to meet the requirements of high-frequency signal transmission.

Definition of high frequency pcb communication circuits

High-frequency circuit board, as a special circuit board, is mainly suitable for occasions with high electromagnetic frequency, especially in the fields of high frequency (frequency greater than 300MHz or wavelength less than 1 meter) and microwave (frequency greater than 3GHz or wavelength less than 0.1 meter).

It is a circuit board made on a microwave substrate copper-clad board by adopting some manufacturing processes or special processing methods of ordinary rigid circuit boards. Generally speaking, when the frequency of the circuit board reaches above 1GHz, it can be defined as a high-frequency board.

With the rapid development of science and technology, more and more equipment designs have begun to involve microwave frequency bands (>1GHz) and even expanded to the millimeter wave field (such as 77GHz), especially in popular applications such as 77GHz millimeter wave antennas on vehicles.

This trend not only promotes the continuous increase in frequency, but also puts higher requirements on the substrate of the circuit board.

For example, the substrate material needs to have excellent electrical properties, stable chemical properties, and as the frequency of the power signal increases, the loss on the substrate must be extremely small. Therefore, the importance of high-frequency boards is becoming more and more prominent.

Advantages of high frequency pcb communication circuits

The main advantages of high frequency pcb communication circuits include efficient data transmission, strong anti-interference ability, high-frequency bandwidth and high reliability. ‌

high frequency pcb communication circuits can achieve efficient data transmission. High-frequency signals have a short cycle and can transmit more information per unit time, so they have the advantage of large-capacity transmission. In addition, high-frequency signals can achieve fast signal processing and are suitable for application scenarios that require high-speed data transmission and high real-time requirements.
high frequency pcb communication circuits have strong anti-interference capabilities. Due to the short wavelength of high-frequency signals, they can better avoid external interference and attenuation and have strong anti-interference capabilities. This makes high-frequency signals have advantages in fields such as wireless communications and radar systems, and can achieve stable signal transmission and reception. ‌
high frequency pcb communication circuits also have the advantage of high-frequency bandwidth. High-frequency signals correspond to a larger frequency range and can provide higher bandwidth than low-frequency signals. This means that more data can be transmitted, thereby supporting higher data rates and richer media content. ‌
High reliability of high frequency pcb communication circuits is also one of its advantages. The use of high-quality materials and manufacturing processes can effectively resist external interference and oxidation corrosion, ensure stable performance in high temperature environments, and thus extend the service life of the circuit board.

Classification of high frequency pcb communication circuits

Classification by material:

Organic materials: including phenolic resin, glass fiber/epoxy resin, Polyimide, BT/Epoxy (bismaleimide triazine/epoxy resin), etc.
Inorganic materials: mainly including aluminum, copper-invar-copper, ceramic, etc. These materials are mainly selected for their excellent heat dissipation function.

Classification by the hardness of the finished product:

Rigid PCB: has a solid structure and stable performance.
Flexible PCB: has flexibility and bendability, suitable for occasions requiring flexible wiring.
Rigid-Flex PCB: It combines the characteristics of rigid and flexible boards, and has higher design flexibility and wide application.

Classification by structure:

Single-sided board: A circuit board with a conductive layer on only one side.
Double-sided board: Both sides are coated with conductive layers, separated by insulating materials in the middle.
Multilayer board: It is composed of multiple conductive layers and insulating layers, and has higher circuit integration and reliability.

Classification by use:

Communication board: It is used in various communication equipment and systems.
Consumable electronic board: It is commonly found in consumer electronic products.
Military board: A circuit board that meets special requirements in the military field.
Computer board: A circuit board used in computer hardware.
Semiconductor board: A circuit board used in the manufacturing and testing process of semiconductors.
Electrical test board: A circuit board used in electronic testing and measurement equipment.

How to choose high-frequency circuit board high-speed board

When choosing PCB board, you must find a balance between meeting design requirements, mass production and cost. In short, the design requirements cover two aspects: electrical performance and structural reliability. Especially when designing ultra-high-speed PCB (frequency greater than GHz), the choice of board is particularly important. For example, the commonly used FR-4 material will have a significantly increased dielectric loss (Df, i.e., Dielectric Loss) at a frequency of several GHz, and may no longer be applicable.

Taking the 10Gb/S high-speed digital signal as an example, this signal can be regarded as the superposition of multiple sinusoidal wave signals of different frequencies. Therefore, the 10Gb/S signal contains multiple components of different frequencies: such as a 5GHz fundamental signal, a 3rd-order 15GHz signal, a 5th-order 25GHz signal, and a 7th-order 35GHz signal. In order to ensure the integrity of digital signals, maintain the steepness of the upper and lower edges of the signals, and be compatible with the low-loss, low-distortion transmission of RF microwaves (the high-frequency harmonic part of the digital signal reaches the microwave frequency band), the selection of materials for high-speed digital circuit PCBs has many similarities with the needs of RF microwave circuits.

In actual engineering operations, the selection of high-frequency boards seems simple, but the factors that need to be considered are quite complex. Through the introduction of this article, PCB design engineers or high-speed project leaders can have a deeper understanding of the characteristics and selection of boards. Understand the electrical properties, thermal properties, reliability and other characteristics of the board, and use the stacking design reasonably to create products with high reliability and excellent processability, and achieve the best balance of various factors.

Composition and key components of high frequency pcb communication circuits

High frequency pcb communication circuits are basically composed of passive components, active devices and passive networks. Passive components include resistors, capacitors and inductors, which mainly exhibit resistance characteristics at low frequencies, but also exhibit reactance characteristics at high frequencies. Active devices such as high-frequency triodes have the characteristics of high gain, high frequency response and low noise, and are widely used in television, radio communication, radar and other fields.

Application of high frequency pcb communication circuits

High frequency pcb communication circuits are widely used in long-distance communication systems, with a communication distance of up to thousands of kilometers, and are often used to maintain communication between aircraft and bases. It occupies a high-frequency band of 2~30MHz, uses skywave propagation, and can propagate over long distances. Modern airborne high-frequency communication systems usually use single-sideband communication systems, which can greatly compress the occupied frequency band and save transmission power. However, high-frequency communication is also susceptible to electrical interference such as ionospheric disturbances and lightning, generating radio background noise, and there is fading, and the signal is sometimes strong and sometimes weak.

Design Guidelines for High Frequency PCB Communication Circuits

Design Guidelines

High Frequency PCB Communication Circuits

How to avoid high-frequency interference?

The basic idea of avoiding high-frequency interference is to minimize the interference of the electromagnetic field of high-frequency signals, which is the so-called crosstalk. You can increase the distance between high-speed signals and analog signals, or add ground guard/shunt traces next to analog signals. Also pay attention to the noise interference of digital ground to analog ground.

How to solve the signal integrity problem in high-frequency communication PCB design?

Signal integrity is basically an impedance matching problem. The factors that affect impedance matching include the architecture and output impedance of the signal source, the characteristic impedance of the trace, the characteristics of the load end, and the topology of the trace. The solution is to rely on termination and adjust the topology of the trace.

How is the differential wiring method implemented?

There are two points to note when wiring differential pairs. One is that the length of the two lines should be as equal as possible, and the other is that the spacing between the two lines (this spacing is determined by the differential impedance) should remain unchanged, that is, they should be kept parallel. There are two parallel methods, one is that two lines run on the same routing layer (side-by-side), and the other is that two lines run on two adjacent layers (over-under). Generally, the former side-by-side (side by side, shoulder to shoulder) is more commonly used.

How to implement differential routing for clock signal lines with only one output end?

To use differential routing, it must be meaningful if both the signal source and the receiving end are differential signals. Therefore, differential routing cannot be used for clock signals with only one output end.

Can a matching resistor be added between the differential line pairs at the receiving end?

The matching resistor between the differential line pairs at the receiving end is usually added, and its value should be equal to the value of the differential impedance. This will improve the signal quality.

Why should the routing of differential pairs be close and parallel?

The routing method of differential pairs should be appropriately close and parallel. The so-called appropriate proximity is because this spacing will affect the value of differential impedance, which is an important parameter for designing differential pairs. Parallelism is also required because the consistency of differential impedance must be maintained. If the two lines are sometimes far away and sometimes close, the differential impedance will be inconsistent, which will affect the signal integrity and timing delay.

How to deal with some theoretical conflicts in actual wiring?

Basically, it is right to separate the analog/digital ground. It should be noted that the signal routing should try not to cross the split place (moat), and the return current path of the power supply and signal should not be too large.

The crystal oscillator is an analog positive feedback oscillation circuit. To have a stable oscillation signal, the loop gain and phase specifications must be met. The oscillation specification of this analog signal is easily interfered. Even if ground guard traces are added, it may not be possible to completely isolate the interference. Moreover, if it is too far away, the noise on the ground plane will also affect the positive feedback oscillation circuit. Therefore, the distance between the crystal oscillator and the chip must be as close as possible.

It is true that there are many conflicts between high-speed wiring and EMI requirements. But the basic principle is that the resistors, capacitors or ferrite beads added due to EMI cannot cause some electrical characteristics of the signal to not meet the specifications. Therefore, first use the techniques of arranging routing and PCB stacking to solve or reduce EMI problems, such as routing high-speed signals on the inner layer. Only then use resistors, capacitors or ferrite beads to reduce damage to the signal.

How to solve the contradiction between manual routing and automatic routing of high-speed signals?

Most of the current powerful routing software’s automatic routing tools have set constraints to control the winding method and the number of vias. The winding engine capabilities and constraint setting items of various EDA companies are sometimes very different. For example, whether there are enough constraints to control the winding method of the serpentine, whether the routing spacing of the differential pair can be controlled, etc. This will affect whether the routing method generated by automatic routing can meet the designer’s ideas. In addition, the difficulty of manually adjusting the routing is also related to the ability of the winding engine. For example, the pushing ability of the routing, the pushing ability of the via, and even the pushing ability of the routing to the copper plating, etc. Therefore, choosing a routing tool with a strong winding engine capability is the solution.

About test coupon.

The test coupon is used to measure the characteristic impedance of the produced PCB board with TDR (Time Domain Reflectometer) to see if it meets the design requirements. Generally, the impedance to be controlled is single line and differential pair. Therefore, the trace width and line spacing (when there is a differential pair) on the test coupon should be the same as the line to be controlled. The location of the ground point during measurement is important. In order to reduce the inductance of the ground lead, the grounding point of the TDR probe is usually very close to the probe tip, so the distance and method between the point where the signal is measured on the test coupon and the ground point should be consistent with the probe used.

In high-speed PCB design, the blank area of the signal layer can be copper-plated, and how should the copper of multiple signal layers be distributed in grounding and power supply?

Generally, the copper plating in the blank area is mostly grounded. However, when plating copper next to high-speed signal lines, pay attention to the distance between the copper plating and the signal line, because the copper plating will reduce the characteristic impedance of the trace a little. Also be careful not to affect the characteristic impedance of other layers, such as in the dual strip line structure.

Can the signal line on the power plane be calculated using the microstrip line model? Can the signal between the power and ground planes be calculated using the stripline model?

Yes, both the power plane and the ground plane must be considered as reference planes when calculating the characteristic impedance. For example, a four-layer board: top layer-power layer-ground layer-bottom layer. At this time, the model of the characteristic impedance of the top layer routing is a microstrip line model with the power plane as the reference plane.

Can the automatic generation of test points on high-density printed circuit boards by software generally meet the test requirements of mass production?

Whether the test points automatically generated by general software meet the test requirements depends on whether the specifications for adding test points meet the requirements of the test equipment. In addition, if the routing is too dense and the specifications for adding test points are strict, it may not be possible to automatically add test points to each line. Of course, the places to be tested need to be filled manually.

Will adding test points affect the quality of high-speed signals?

As for whether it will affect the signal quality, it depends on the way of adding test points and how fast the signal is. Basically, the additional test point (without using the existing via or DIP pin as the test point) may be added to the line or a short line may be pulled out from the line. The former is equivalent to adding a very small capacitor to the line, and the latter is an additional branch. Both situations will have some impact on the high-speed signal, and the degree of impact is related to the frequency speed of the signal and the edge rate of the signal. The magnitude of the impact can be known through simulation. In principle, the smaller the test point, the better (of course, it must meet the requirements of the test equipment) and the shorter the branch, the better.

How should the ground wires between the boards of a system be connected when several PCBs are connected to each other?

When the signals or power supplies between the PCB boards are in operation, for example, when the power supply or signal from board A is sent to board B, there will be an equal amount of current flowing back from the ground layer to board A (this is Kirchoff current law). The current on the ground layer will flow back to the impedance. Therefore, at each interface where the power supply or signal is connected to each other, the number of pins allocated to the ground layer should not be too small to reduce the impedance, so as to reduce the noise on the ground layer. In addition, the entire current loop can be analyzed, especially the part with larger current, and the connection method of the ground layer or ground wire can be adjusted to control the flow of current (for example, create low impedance at a certain place to let most of the current flow through this place) to reduce the impact on other more sensitive signals.

What is High Density Interconnect PCB?

High density Interconnect (HDI) PCB is a printed circuit board designed to meet the growing needs of modern electronic products. It allows for higher component density due to the use of thinner lines, smaller through-holes, and precise component placement. These boards are particularly popular in industries where miniaturization is key, such as smartphones, medical devices, and military equipment.

The HDI board uses the micro-blind hole technology to realize the circuit board design with high line distribution density, which is especially suitable for applications requiring high performance and high reliability. Compared with traditional PCBs, HDI boards have significant advantages in terms of volume, weight, wiring density and electrical performance, which can meet the electrical requirements of high-speed signals, provide impedance control of alternating current characteristics, high-frequency transmission capacity and reduce unnecessary radiation (EMI).

HDI PCBs use a combination of advanced technologies such as laser drilling and sequential lamination to enable denser wiring without compromising performance. By integrating smaller, more efficient through-holes, HDI boards offer greater functionality on a smaller footprint than traditional PCBs.

What is the Difference Between Connect and Interconnect?

The terms “connect” and “interconnect” may seem similar but serve distinct functions in electronics. “Connect” typically refers to the linking of two points, components, or circuits. This could be as simple as joining a wire to a terminal.

On the other hand, “interconnect” deals with more complex connections, usually involving the linking of multiple circuits or components within a system. In the context of HDI PCBs, interconnectivity is crucial because it defines how different layers and components of the board communicate. HDI technology optimizes these interconnections to make the board more efficient in terms of space and performance.

What is HDI PCB Stackup?

The stackup in HDI PCBs refers to how the multiple layers of the board are arranged. Stackups are critical in determining the board’s performance, particularly when it comes to signal integrity, power delivery, and heat dissipation. HDI stackups often involve intricate configurations that vary depending on the design’s complexity and purpose. Here are the most common types:

HDI PCB (1+N+1)

This is one of the simplest forms of HDI stackups, where “1+N+1” means there are two layers of high-density interconnect (one on each side) sandwiching N layers of traditional PCB. This structure is often used in applications where moderate complexity is required, providing a balance between performance and cost.

HDI PCB (2+N+2)

In this configuration, there are two HDI layers on each side of the N traditional layers. This setup allows for greater flexibility in routing, especially for complex designs requiring more components. The additional HDI layers enhance the board’s ability to manage signal transmission efficiently, making it suitable for high-performance applications.

ELIC (Every Layer Interconnection): Most Complex HDI

ELIC takes HDI technology to the next level. In this configuration, every layer of the PCB can interconnect directly with any other layer. This is the most advanced form of HDI stackup, offering unparalleled design flexibility and performance. However, it is also the most complex and expensive option. ELIC is often used in cutting-edge technology applications such as aerospace and military equipment.

Other HDI Stackups

What are the Advantages of HDI PCB?

The main advantage of the HDI board is its high-density interconnect design, through the use of micro lines and highly compact layout, can achieve higher interconnection density, thereby accommodating more electronic components in a limited space, improving the performance and function of the board. This design makes HDI boards particularly suitable for applications requiring high performance and high functional density, such as high performance computing, data centers, and mobile communication equipment, to support high-speed data transmission and processing.

The design of the HDI board also focuses on improving the anti-interference ability and reliability of the circuit board, by using better signal integrity and power management technology, effectively reduce the impact of electromagnetic interference and power noise on the circuit.

However, HDI boards also have some limitations. First of all, compared with other advanced boards, the cost of HDI boards is usually lower, because HDI manufacturing technology helps to use advanced packaging technology, but its processing is more difficult, higher requirements for technology and equipment, which may increase a certain cost. In addition, the material choice of HDI board will also affect its performance and cost, such as FR4, PI and BT materials have advantages and disadvantages, need to be weighed according to the specific application needs.

5 Types of Vias in HDI PCB

HDI PCBs rely on several types of vias to achieve their high-density interconnections. Each type of via has its specific role in the design and manufacturing process.

Blind Vias

Blind vias connect an outer layer of the PCB to one or more inner layers but do not extend through the entire board. These vias allow for complex routing without using unnecessary space on the PCB’s inner layers.

Buried Vias

Buried vias are located entirely within the board, connecting internal layers without appearing on the outer surfaces. This is ideal for designs where surface area needs to be preserved for components, while still allowing inter-layer connectivity.

Microvias

Microvias are tiny vias, typically created using laser drilling, that connect adjacent layers of the PCB. These are essential for HDI designs as they save space while maintaining high-density connections. They can be used in stacked or staggered configurations to optimize space and signal flow.

Staggered Vias

Staggered vias are microvias that are offset from each other across layers. This design allows for more flexibility in routing and avoids overlapping, making it a popular choice for HDI PCBs that require complex routing.

Through Hole Vias

Though not exclusive to HDI designs, through-hole vias extend through the entire PCB, connecting all layers. While these vias occupy more space, they are sometimes necessary for power connections or when working with thicker boards.

What is the Difference Between PCB and HDI PCB?

The key difference between a traditional PCB and an HDI PCB lies in the design and manufacturing process. Traditional PCBs use through-hole technology and thicker traces, limiting the board’s ability to accommodate high-density components. HDI PCBs, by contrast, use finer lines, smaller vias, and advanced interconnect techniques to maximize component density. Here are some key differences between them:

Manufacturing Processes

The embedded via and blind via technologies used in the manufacturing process of HDI (High-Density Interconnect) boards allow for the addition of more layers without increasing the thickness of the board, thereby improving space utilization. In contrast, the drilling process for standard PCBs is relatively simple, but as the number of layers increases, the board thickness also increases accordingly. This difference means that HDI boards require more advanced equipment and higher technical requirements during production.

Space Constraints

In space-constrained devices, such as smartphones and portable electronics, HDI boards are the ideal choice because they can integrate more functions within a smaller size. HDI boards can achieve a line width of 2/2 mil and a 10-layer board thickness of below 0.8mm. Standard PCBs, due to their larger size and lower integration, may not be suitable for these applications. The line width and spacing of regular PCBs are generally limited to 3/3 mil, and their thickness also has certain restrictions.

Performance Requirements

For high-end electronic products that require high-speed signal processing and complex circuit designs, HDI boards offer better performance. Due to their high density and efficiency, HDI boards can meet the high-performance demands of modern electronic devices. Standard PCBs, on the other hand, may not be suitable for these applications because of their lower signal transmission quality and higher latency.

Different Layering Methods

HDI boards are created through continuous stacking and lamination, resulting in advantages such as being “light, thin, short, and small.” Electrical interconnections between layers are achieved through conductive vias, embedded vias, and blind vias, making the structure different from standard multilayer boards. Most HDI boards are laminated two or more times (except for special structures), while standard boards are typically laminated once.

PTH vs. HDI PCB

Plated Through Hole (PTH) technology is commonly used in traditional PCBs and involves drilling holes through the entire board to connect different layers. This method, while reliable, is limited in terms of design flexibility and component density.

HDI PCBs, on the other hand, use smaller vias such as microvias, blind vias, and buried vias. These allow for more efficient use of space, making HDI technology the go-to solution for high-density, multi-layer designs.

High Density Interconnect PCB Applications

Communication equipment
Computers and servers
Automotive electronics
Medical equipment
Industrial control equipment
Consumer electronics
ADAS system
Wireless connection module

For nearly 20 years, Best Technology have always been committed to providing overseas customers High Mixed, Low Volume products with Reliable Quality and Quick Delivery, and are determined to become one of most trusted partners in the field of printed circuit boards and PCBA. As an expert of HDI PCB manufacturer, we are so confident that we can provide the highest quality product that highly meet your specifications.

What is hdi pcb?

HDI stands for High Density Interconnect, which refers to high-density interconnect technology. HDI circuit board is a high-end printed circuit board with very high circuit density and complexity, which can achieve high-speed signal transmission and reliability design. The main features of HDI circuit board are multi-layer circuit, thin plate, small aperture, dense wiring and fine circuit. It is widely used in mobile phones, computers, network communications, automotive electronics and other fields. Bestpcb is a professional HDI manufacturer with 18 years of HDI manufacturing experience.

What are the advantages of hdi pcb

Higher line density: HDI PCB can support more circuit tracks, arrange more electronic components in a limited space, and achieve high-density interconnection.
Smaller device spacing: The micro-hole technology of HDI PCB allows smaller spacing between components, which is suitable for compact design.
Improve signal integrity: The advanced stacking layer structure is adopted to provide better signal transmission quality and reduce signal interference.
Improve reliability: The manufacturing process of HDI PCB improves the mechanical strength of the board, making it more durable and suitable for demanding application environments.
Improve circuit integration: More line connections and component arrangements are achieved in a limited circuit board space to meet the needs of modern products that are thin and compact.
Enhance signal transmission efficiency: The use of advanced wires and connection methods can increase the operating speed of electronic devices and reduce energy consumption.
Support more complex system design: High-density connection capabilities provide support for complex system design and give full play to the performance of electronic devices. ‌
Promote innovation in the electronics industry: The application of HDI technology has promoted the innovation and development of the electronics industry, making electronic equipment more intelligent and efficient. ‌
Smaller size: It can complete a large number of circuit connections in a smaller space, meeting the needs of electronic products for lightness and portability. ‌
Higher signal transmission speed: The high-density line design allows signals to be transmitted quickly in a short time, improving the system operation speed and response speed.

Why does HDI PCB need via filling and plating?

‌Via filling plating plays a vital role in ‌HDI PCB manufacturing, with the main purpose of improving ‌electrical performance, connection reliability, operating frequency, and avoiding electromagnetic interference. This technology fills the blind holes of HDI PCB with conductive materials through the electroplating process to form a conductive path, which improves the performance and reliability of electronic equipment.

Improve electrical performance: Via filling plating can improve the electrical performance of HDI PCB, especially in high-frequency circuit board design, which is crucial for improving connection reliability, operating frequency and avoiding electromagnetic interference.
Via plugging and electrical interconnection in one step: Via filling plating technology combines via plugging and electrical interconnection, avoiding the defects caused by resin via filling, and also avoiding the CTE difference caused by other materials via filling.
Improve efficiency: Compared with resin via filling or other materials via filling, via filling plating has a simpler process and higher efficiency.
Process flow and technical challenges of via filling plating
Process flow: including steps such as tank preparation, setting of electroplating process control parameters, and analysis of potion addition.
Technical challenges: including positioning accuracy issues and electroplating quality issues, which need to be solved by strictly controlling parameters such as electroplating time and current density.

Application scenarios of hole filling electroplating

First-order HDI: Suitable for electronic devices with less complex circuits.
Second-order and above blind hole electroplating copper filling: Suitable for more complex electronic devices, such as mobile phones, laptops, etc.
Comparison between hole filling electroplating and full-board electroplating
Full-board electroplating: Although it can provide a uniform surface copper thickness distribution, it may encounter the problem of residual dry film on the board surface or in the hole during pre-treatment, resulting in some areas unable to be plated with copper. In addition, the etching process after full-board electroplating may cause quality defects such as side etching and fine lines.
Hole filling electroplating: Compared with full-board electroplating, hole filling electroplating is more accurate in filling blind holes, avoiding the problems that may be encountered in full-board electroplating, while simplifying the process and improving efficiency.

Materials of HDI PCB

The materials of HDI PCB mainly include coated copper foil (RCC), prepreg, copper foil, etc.

Resin-coated copper foil (RCC): This is a material that coats a special resin film layer on electroplated copper foil, used for HDI insulation layer. The characteristics of RCC include no glass dielectric layer, easy laser and plasma micro-hole forming, extremely high peel strength and good toughness, suitable for micro-narrow line etching. Laser drilling is performed on RCC, and the aperture shape formed is an inverted trapezoid, and the general aperture size is 0.076-0.10 mm. The use of RCC makes HDI PCB more widely used in small portable products, such as mobile phones, digital cameras, laptops, etc.

Prepreg and copper foil: These are basic materials in HDI PCB manufacturing, there are no special requirements, and they are suitable for different types of HDI PCB structures. The inner layer circuits are generally 1 ounce copper thick, while the outer layer circuits are plated with half an ounce of base copper to 1 ounce of finished copper thickness. The thickness of the board is usually thinner to meet the miniaturization requirements of HDI PCB.

Other materials: In addition to the main materials mentioned above, the manufacture of HDI PCBs may also involve other materials, such as FR4, PI (polyimide), BT, etc. These materials are selected according to specific application requirements. For example, FR4 has good electrical and mechanical properties and is suitable for most general applications; PI has higher heat resistance and chemical corrosion resistance, and is suitable for high temperature, high humidity and strong acid and alkali environments, but it is more expensive and difficult to process; BT combines good electrical properties, mechanical properties and thermal stability, and is suitable for application scenarios that require higher heat resistance.

Classification of HDI circuit boards

HDI circuit boards are mainly divided into first-order, second-order, third-order, high-order (including fourth-order and above) and Anylayer HDI. ‌

First-order HDI circuit boards mainly include single-sided or double-sided micro-hole processes, and the circuit layer has only one layer. ‌This type of HDI circuit board is suitable for applications with high requirements on cost and space, such as consumer electronics. ‌
Second-order HDI circuit boards contain two circuit layers, which are more complex but also more powerful than first-order HDI circuit boards. They can handle higher signal frequencies and are suitable for applications that require high performance, such as high-end communication equipment and computer hardware. ‌
Third-order HDI circuit boards contain three circuit layers. They are the most complex type at present. They can handle the highest signal frequency and the maximum data transmission rate. They are usually used in applications that require the highest performance, such as aerospace and military equipment. ‌
High-order HDI (including fourth-order and above) The applications of third-order or fourth-order HDI in electronic terminal products are more, while those above fourth-order are mostly converted to Anylayer structure. ‌
Anylayer HDI refers to HDI of any order/any layer. Compared with PCB boards with traditional lamination processes, HDI can reduce costs to a lower level when the stacking density exceeds eight layers. It also has higher electrical performance and signal accuracy, and significantly improves the performance of electromagnetic waves and radio frequency interference, electrostatic discharge and heat conduction in interconnection and relay transmission.

HDI PCB Process Flow

The process flow standards of HDI PCB mainly involve the application and processing technology of high-density interconnection technology (High Density Interconnection Technology, HDI for short), including first-order, second-order and third-order processes. Specifically, the HDI PCB process flow includes the following key steps and characteristics:

First-order process (1+N+1): This is a basic high-density interconnection technology that manufactures multi-layer boards through build-up and micro-blind via technology.

Second-order process (2+N+2): Further development on the basic technology, adding more layers and complexity.

Third-order process (3+N+3): Represents the highest stage of HDI technology, with extremely high layers and interconnection density

Differences between HDI PCB and ordinary PCBs

Differences in circuit design:
HDI PCB adopts a more sophisticated circuit design, with smaller line width and spacing, and smaller aperture, which can integrate more electronic components and realize more complex circuit functions. ‌
The blind, buried and stacked hole designs of HDI PCB greatly improve the utilization rate and signal transmission performance of the circuit board.
Differences in manufacturing process:
The manufacturing process of HDI PCB is more complicated, requiring high-precision processes such as laser drilling technology, hole filling electroplating technology and photolithography technology.
The manufacturing cost of HDI PCB is relatively high, but the performance and reliability are also higher. ‌
Differences in application:
Due to its high density and high performance, HDI PCB is widely used in high-end electronic products, such as smartphones, tablets, high-end communication equipment, etc.
Ordinary PCB is mainly used in low-end electronic products and general electronic equipment.
Characteristics and application scenarios of HDI PCB:
HDI PCB has high-density wiring, multi-layer structure, high-precision manufacturing process and excellent electrical performance, which can meet the extremely high requirements of high-end electronic products for size, weight, performance and reliability.
HDI PCB is widely used in smart phones, tablet computers, high-end communication equipment and other fields, promoting the continuous development and upgrading of electronic products.

Application of HDI PCB

HDI PCB (High Density Interconnection Printed Circuit Board) is widely used in multiple industries, including medical equipment, mobile phones, laptops, automotive electronics, computer industry, and future 5G technology fields

Medical equipment: The application of HDI PCB in medical equipment, such as sphygmomanometers and ultrasonic imaging systems, achieves accurate measurement of blood pressure and high-definition imaging of the internal structure of the body, providing patients with timely and accurate diagnosis and treatment information. ‌
Mobile phone industry: With the increasingly miniaturized design of mobile phones, HDI PCB is widely used in transceiver modules, motherboards, SIM card interfaces, fingerprint recognition modules and other parts of mobile phones due to its high density, high quality and high reliability. ‌
Computer industry: In the computer industry, the application of HDI PCB improves the performance of computers, especially in the fields of high-speed algorithms and multimedia applications, and adapts to the miniaturization trend of computer equipment2. ‌
Automotive electronics: HDI PCB has broad application prospects in the field of automotive electronics. In addition to the dominant mobile phone market, it also involves multiple fields such as automobiles, modules and artificial intelligence, demonstrating its key role in complex electronic systems. ‌
Future development trends: With the advent of 5G technology, the demand for HDI PCB will continue to increase, requiring higher speeds and frequencies while adapting to smaller and thinner device designs. Research new micro HDI PCB boards to adapt to future development trends. ‌

Why is PCB Board So Expensive?

The cost of a PCB can sometimes seem high due to several reasons. Firstly, the complexity of the design plays a significant role. High-density interconnect (HDI) PCBs, multi-layer PCBs, and those requiring advanced materials or special finishes can drive up the cost. Additionally, stringent quality control measures and the need for precise manufacturing processes add to the expense.

Another factor is the cost of raw materials. Copper, laminates, and specialty substrates can vary in price, affecting the overall cost of the PCB. Furthermore, labor costs in the region where the PCB is manufactured, along with overhead costs such as utilities and facility maintenance, contribute to the final price.

What Factors Affect the PCB Board Cost?

PCB board can cost from $10 to $500 to produce. Buyers are always amazing that why PCB cost so high? But they don’t know there are numerous factors a manufacturer considers in determining PCB costs. If you are in the market to design a PCB, this guide provides factors to consider that could increase or decrease the cost of circuit boards.

Manufacture technology

The specific technology used in the PCB can significantly impact the cost. Advanced technologies such as HDI (High-Density Interconnect), embedded busbar or flexible PCBs often require more complex manufacturing processes, which can increase the cost.

Material Type

The type of materials used for the PCB, such as standard FR4, high-frequency laminates, or other specialty substrates, can influence the cost. Higher quality or specialized materials typically cost more.

IPC Grade

The IPC standards and grades indicate the quality and reliability requirements of the PCB. In electronics manufacturing, printed circuit boards are divided into three levels: level 1, level 2 and level 3. These grades reflect the quality level of each board type, from the lowest (Level 1 standard) to the highest (Level 3 standard). This classification system was developed and defined by IPC and is specified in the IPC-6011 series.

Circuit Design

The complexity of the circuit design, including the number of layers, trace width, and spacing, affects the cost. More intricate designs require more precision and advanced techniques, leading to increased expenses.

PCB Size & Yield

The physical dimensions of the PCB and the yield rate during production play a role in the overall cost. Larger boards or designs with lower yield rates (more defects) will typically cost more to produce.

Material Thickness

The thickness of the materials used in the PCB construction, such as the substrate and copper layers, can impact the cost. Thicker materials may be more expensive and require more resources to process.

Copper Thickness

The thickness of the copper used in the PCB, measured in ounces per square foot, can affect the cost. Thicker copper layers provide better electrical performance but are more expensive.

Stack-up

The method of layering and stacking the materials in the PCB, known as the stack-up configuration, can influence the cost. Complex stack-ups with multiple layers and specific arrangements can be more costly to manufacture. Read our another post of How Can I Reduce and Optimize the Cost of My PCB in A Best Way?

Manufacturing Process of A Standard PCB

PCB Design and Layout

The manufacturing process begins with the design phase, where engineers use CAD (Computer-Aided Design) software to create the PCB layout. This includes defining the circuit paths, components, and layers, ensuring the design meets the electrical and mechanical requirements.

Once the design is finalized, a photomask is created, which is a transparent film with the PCB design printed on it. The PCB substrate, typically made of FR4, is then coated with a light-sensitive material called photoresist.

Drilling

Precise holes are drilled into the board for through-hole components and vias using computer-controlled drilling machines. The board is cleaned and deburred to remove any rough edges or debris from the drilling process.

Plating and Copper Deposition

A thin layer of copper is deposited on the surface of the board and inside the drilled holes through an electroless plating process, providing a conductive base. Additional copper is electroplated onto the board, building up the thickness of the copper traces and plated through-holes.

Pattern Transfer

The photomask is placed over the photoresist-coated substrate and exposed to ultraviolet (UV) light. The UV light hardens the photoresist where the design allows light to pass through, and the board is then developed to wash away the unhardened photoresist, leaving behind the desired circuit pattern.

Etching

The PCB undergoes an etching process using a chemical solution to remove unwanted copper, leaving only the copper traces that form the circuits. The remaining hardened photoresist is then stripped away to reveal the clean copper pattern.

Applying Solder Mask

A layer of solder mask is applied to the board to protect the copper traces from oxidation and prevent solder bridges during assembly. The solder mask is cured using UV light, hardening it and making it durable.

Surface Finish/Surface Treatment

A surface finish is applied to the exposed copper areas to protect them and facilitate soldering. Common finishes include HASL (Hot Air Solder Leveling), ENIG (Electroless Nickel Immersion Gold), and OSP (Organic Solderability Preservatives).

Outline Routing

One the surface treatment finish, it will be routed according to the manufacturing file by CNC machine. And then individual PCBs are cut from the larger panel using routing or V-scoring, depending on the board design and requirements.

Electrical Testing & FQC

The PCB undergoes electrical testing to check for short circuits, open circuits, and other defects. This is typically done using a flying probe tester or a bed-of-nails tester. Then the board is visually inspected for any cosmetic defects or anomalies, and further tests and inspections are performed to ensure the PCB meets all specified requirements and standards. Below you can see the full manufacturing process video of a PCB:

Best Technology – A 18+ Years Experience PCB Manufacturer

When you are looking for a reliable PCB manufacturer, considering Best Technology. We have transparent price and 5years quality warranty. We 24/7 hours online and welcome all the technical questions and PCB inquiries. Contact us for more!

Why use mcpcb for led ring light pcb

With the continuous development of LED technology, the heat generated by LEDs has gradually increased. The traditional FR4 printed circuit board (PCB) has been unable to meet the heat dissipation requirements due to its low thermal conductivity (only 0.36W/m.K). In order to solve this problem, the metal core printed circuit board (MCPCB) was proposed. It attaches the original printed circuit board to a metal with better thermal conductivity (such as aluminum and copper) to enhance the heat dissipation effect. The thermal conductivity efficiency of MCPCB is higher than that of traditional FR4 PCB, reaching 1W/m.K to 2.2W/m.K, which effectively improves the heat dissipation performance of LED PCB.

In addition, the use of MCPCB can also reduce the number of LEDs required to generate lighting, making it an ideal choice for street lights, automotive LED applications, and backlight unit applications. The use of metal substrates has practical advantages in heat dissipation, thermal conductivity, reliability, and electrical insulation, especially in harsh environments, and can also achieve reliable operation of LEDs. For example, using a metal substrate can reduce the LED junction temperature by 20-30°C, improve light output and enhance the overall performance of the product, ensure consistent UV light generation, and expand the possibilities of UV applications in various industries.

Unveiling the Components of LED PCBs

LED Chips: The heart of the LED PCB, these semiconductor chips emit light when current passes through them.
Substrate Material: The base layer of the PCB provides mechanical support and thermal conductivity.
Copper Traces: These conductive pathways connect the LEDs and other components, allowing current to flow through the circuit.
Solder Mask: A protective layer that covers the copper traces, safeguarding them from external factors and preventing short circuits.
Silkscreen: This layer contains markings and labels, providing important information about the PCB’s components and assembly.

Advantages of led ring light pcb?

Thermal performance advantages of metal substrate PCB

High thermal conductivity:
The thermal conductivity of metal substrate PCB is much better than that of traditional plastic substrates such as FR4. It can effectively conduct the heat generated by components, reduce the operating temperature of components, and improve the reliability and life of circuit boards.

Good thermal stability:
Metal substrate PCB can maintain good dimensional stability and electrical performance in high temperature environment, and is suitable for high temperature working environment.

Mechanical performance advantages of metal substrate PCB

High strength: Metal substrate PCB has high mechanical strength and rigidity, is not easy to deform and break, and can withstand large external forces and vibrations.

Good processability: Metal substrate PCB can be processed by conventional mechanical processing methods such as drilling and cutting, which is convenient for the production of circuit boards with complex shapes and sizes.

Electrical performance advantages of metal substrate PCB
Excellent electrical insulation performance: Metal substrate PCB has a special insulation layer design to ensure good electrical insulation performance and avoid electrical short circuits between components.

Low impedance: The conductive layer of metal substrate PCB is made of metal material, which has low impedance, which is conducive to signal transmission and processing.

How does led ring light pcb dissipate heat?

The power device is mounted on the circuit layer. The heat generated by the device during operation is quickly transferred to the metal base layer through the insulating layer, and then the metal base layer transfers the heat to achieve heat dissipation of the device.

Compared with the traditional FR-4, the aluminum substrate can reduce the thermal resistance to the minimum, making the aluminum substrate have excellent thermal conductivity; compared with the thick film ceramic circuit, its mechanical properties are extremely good.

In the circuit design scheme, the heat diffusion is handled very effectively, thereby reducing the module operating temperature, extending the service life, and improving the power density and reliability; reducing the assembly of the heat sink and other hardware (including thermal interface materials), reducing the product volume, and reducing the hardware and assembly costs; combining the power circuit and the control circuit

How to make a LED light circuit board?

Step 1: Design Your LED PCB:
Using PCB design software, create a schematic for your LED circuit and design the PCB layout, considering component placement and signal flow.

Step 2: Choose the Materials:
Select a suitable substrate material and copper-clad board based on your project requirements.

Step 3: Transfer the Design:
Print your PCB layout onto a special transfer paper and transfer it onto the copper-clad board using a heat press.

Step 4: Etch the Board:
Immerse the board in an etching solution to remove the excess copper and reveal the copper traces.

Step 5: Drill Holes:
Drill holes on the board to accommodate the LED chips and other components.

Step 6: Solder the Components:
Carefully solder the LED chips and other components onto the board, ensuring secure connections.

Step 7: Test Your LED PCB:
Connect your LED PCB to a power source and test the LEDs to ensure they light up correctly.

How to make a LED light circuit board?

Capabilities of led ring light pcb?

Item	Capabilities
Layer Count	1 – 10 Layers
Max Board Dimension	2464″(6101625mm)
Min Board Thickness	0.6mm
Max Board Thickness	4.0mm
Conductor Thickness	0.5oz – 10oz
Min Line Width/Line Space	4/4mil (0.10/0.10mm)
Min Hole Diameter	10mil (0.25mm)
Min Punch Hole Dia	0.12″ (3.0mm)
Min Hole Spacing	16mil (0.4mm)
Min PAD Ring(Single)	3mil (0.075mm)
PTH Wall Thickness	Normal: 0.59mil (15um); HDI: 0.48mil (12um)
Min Solder PAD Dia	14mil (0.35mm)
Min Soldermask Bridge	8mil (0.20mm)
Min BAG PAD Margin	5mil (0.125mm)
PTH/NPTH Dia Tolerance	PTH: ±3 mil (0.075mm); NPTH: ±2mil (0.05mm)
Hole Position Deviation	±3mil (0.075mm)
Outline Tolerance	CNC: ±6 mil (0.15mm); Die Punch: ±6 mil (0.1mm)
Max Aspect Ratio	10:01
Surface Treatment	ENIG, Flash Gold, Hard Gold Finger, Gold Plating(50mil), Gold finger,

	Selected Gold Plating, ENEPIG, ENIPIG, HAL, HASL(LF), OSP, Silver Imm., Tin Imm

Capabilities

Applications of led ring light pcb?

Application in medical equipment
The rapid progress of medicine is closely related to the rapid development of the electronics industry. Many medical devices are made of basic PCBs alone, such as pH meters, heart rate sensors, temperature measurements, electrocardiographs, electroencephalographs, MRIs, X-ray machines, CT scanners, blood pressure machines, blood sugar level measuring equipment, etc.
Application in industrial equipment
PCBs are widely used in manufacturing, especially in industries with high-power mechanical equipment; these devices run on high power and require high current circuit drive. Such as arc welding, large servo motor drives, lead-acid battery chargers, clothing cotton machines, etc.
Application in lighting
LED lights and high-intensity LEDs are mounted on PCBs based on aluminum substrates; aluminum has the property of absorbing heat and dissipating it in the air.
Application in the automotive and aerospace industries
Flexible PCBs are lightweight but can withstand high vibrations. Because of their light weight, they can reduce the total weight of spacecraft; flexible PCBs can be adjusted even in narrow spaces. These flexible PCBs are used as connectors, interfaces, and can be assembled even in compact spaces

FAQs About led ring light pcb

What is the thermal conductivities and withstanding voltages of BT/FR4 layer and Dielectric layer?
The SinkPAD conducts heat primarily through the copper base (400W/m.K), the withstanding voltages of Dielectric layer is around 4KV.

What is the placement accuracy for the SMT components?
+/-0.05mm is our SMT accuracy tolerance. You are welcome to come to our SMT factory in Shenzhen China and Vietnam.

Can the aluminum be made as the base of sinkpad MCPCB?

Actually, the sinkpad can only use copper as the base.
As you can see the below manufacturing steps, the SinkPad will etch the copper base into convex platform with Copper Etching Solution, then hollow out the Double Layer FR4 PCB, and do lamination with the convex platform.
However, regarding of current technical conditions, since aluminum or aluminum alloy cannot directly react with acid, the reaction process is too complex and difficult to control, which will increase the difficulty of etching the LED pad platform. Considering the scrap rate, the process of etching LED pad platform with aluminum is more complex and the overall cost is higher.

Can I plated copper in mcpcb via holes?
Generally speaking, copper plating through holes requires hole rings, otherwise the copper in the hole wall will easily fall off.

In addition, if it is a copper substrate, through the hole first to resin plug before copper plating.

Otherwise there’s no chemical reaction between copper and copper. And if the copper layer is connected to each copper layer, it is easy to short circuit.

Are you UL certified led pcb manufacturer?

Yes, we are UL certified manufacturer, our UL is E475635. We have already passed UL certificated. Meanwhile, we are passed ISO9001, ISO13485 and IATF16949 certifications.

Our LED pcbs are manufactured under highly monitored by these quality system controls.

How does the conveity of sinkpad manufactured?

Actually the sinkpad can only use copper as the base.

As you can see the below manufacturing steps, the SinkPad will etch the copper base into convex platform with Copper Etching Solution, then hollow out the Double Layer FR4 PCB, and do lamination with the convex platform.However, regarding of current technical conditions, since aluminum or aluminum alloy cannot directly react with acid, the reaction process is too complex and difficult to control, which will increase the difficulty of etching.

What is a printed circuit board?

Before knowing the methods of testing circuit board, let’s understand the definition of PCB. A PCB is a flat board made from insulating materials like fiber glasses with conductive pathways etched onto its surface. The pathways we called circuit or traces. These pathways connect different electronic components, so that they can communicate and function together. PCBs come in various materials, shapes and sizes, which always is customized to meet specific applications and performance requirements.

PCBs can be divided into different types according to substrate material used. They are – normal FR4 PCB, polyimide flexible PCB, metal core PCB, ceramic PCB, rogers PCB. Different has its own properties and advantages. The choice of materials and the design of the PCB significantly impact the performance and reliability of the final product. Understanding the materials used in PCBs is crucial for anyone involved in electronics, from hobbyists to professional engineers/designers.

Common PCB Circuit Board Issues

Though PCB has a strong construction, they are easy to be broken or failure since they always encounter a range of issues. These problems can stem from manufacturing defects, wear and tear, or improper handling. Identifying and diagnosing these issues promptly is crucial for maintaining the reliability and performance of electronic devices. Common issues we faced are including:

Open Circuits: These occur when a break in the circuits prevents current flow normally. Open circuits can result from physical damage or manufacturing errors.

Short Circuits: Due to improper soldering, unreasonable circuit design and other reasons, resulting in a short circuit between two or more points in the circuit that should not be connected. This can cause excessive current flow, potentially damaging components.

Grounding: The unreasonable design of ground area leads to interference signals on the grounding, which affects the normal operation of the circuit.

Signal: The signal circuit design is not reasonable, resulting in interference signals on the signal.

Component Failures: Individual components on a PCB can fail due to aging, overheating, or electrical stress breakdown. And incorrect orientation will lead to the failure of PCB.

Soldering Issues: Poor soldering can lead to weak connections, causing intermittent faults or complete circuit failure. This including the dents in the solder joints, this also can make the PCB failure.

Corrosion: PCB exposure to moisture and contaminants for a long time can cause corrosion, degrading the conductive pathways and component leads.

How to check a PCB?

In generally, there are four common ways to check whether if your PCB are good or failure.

1. Visual inspection

The easiest way is visual inspection. Through naked eye observation, check whether the solder joint on the PCB circuit board is firm, whether there is short circuit, open circuit and other phenomena. And look for burnt components, discolored areas, or broken traces, such as somewhere became black or be burned obviously. These are clear indicators of damage.

2. Use a multimeter

Multimeter is a common tool used for measuring PCB. Multimeter is versatility and it has multiplied modes. Select the appropriate mode on the multimeter, such as continuity, voltage, or resistance mode, depending on what you are testing. Before testing, make sure probes are in good condition and properly connected to the multimeter, with the red probe typically being positive and the black probe negative or ground. Click here to read What is the PCB flying probe test?

3. E-tester

E-tester is a good way to test short or open circuit when it is a mass production. If you just want to test one piece PCB, multimeter is much better.

4. Use oscilloscope

An oscilloscope is a powerful diagnostic tool used to observe the waveform of electrical signals in a circuit. Connect the oscilloscope probes to the test points on the PCB, it can capture the waveform. By observing the waveform, determine whether the circuit is working normally.

5. Use a thermal imager

A thermal imager also is a effective way to check the condition of PCB. It can capture the temperature distribution on the PCB. It helps identify areas with excessive heat, which can indicate potential issues.

How to Test a Circuit Board with a Multimeter Effectively?

Testing a circuit board with a multimeter is essential for diagnosing and fixing electronic issues. A multimeter can measure voltage, current, and resistance, helping you identify problems with the PCB. The main way to test a PCB with a multimeter is to measure voltage, ‌ resistance, and ground. ‌

Measuring voltage

By measuring the voltage on the circuit board, ‌ can quickly test whether the circuit is working properly. Use the voltage gear of the multimeter, ‌ select the appropriate range, ‌ then measure the input and output of the power supply on the circuit board respectively, ‌ to check whether the voltage is within the normal range. If the voltage is abnormal, ‌ may indicate that the circuit is open or short. ‌

Measuring resistance value

By measuring the resistance value on the circuit board, can detect whether the circuit is smooth. Use the resistance level of the multimeter, select the appropriate range, then measure the key nodes on the circuit board, check whether the resistance value is within the normal range. If the resistance value is abnormal, may indicate that the circuit is open or short. ‌

Check the grounding

Grounding is critical to the proper operation of the circuit board. Use the multimeter’s ground test function, to check that key points on the board are properly grounded, ‌ this helps to spot potential electrical connection problems. ‌

In addition, for industrial-grade PCB measurement, the use of higher-precision multimeters and special pens can improve the accuracy and efficiency of the measurement. ‌ For example, the ‌ Fluke 17B Max multimeter is equipped with an extra-pointed stylus, enables more accurate measurement of patch components and pins, and ‌ improves measurement fineness and accuracy.

Generally speaking, using a multimeter to test the PCB board needs to master the correct measurement methods and skills. At the same time according to the complexity of the circuit board to choose the appropriate measurement tools, to ensure the accuracy and efficiency of the test.

How to Tell if a Circuit Board is Bad?

Identifying a bad circuit board requires a combination of visual inspection and multimeter testing. Here are some signs and methods to determine if a PCB is faulty:

Visual Signs

Look for burnt components, discolored areas, or broken traces, such as somewhere became black or be burned obviously. These are clear indicators of damage.

Component Testing

Use the multimeter to test individual components. A component that doesn’t show the expected resistance or voltage is likely faulty.

Continuity Testin

Check for open circuits. Lack of continuity in a path indicates a broken trace or solder joint.

Short Circuit Detection

Identify any unintended connections between different paths. This can be done by checking for continuity where there should be none.

Functionality Testing

Test the circuit board in its intended application. If the device does not function correctly, there may be an issue with the PCB.

Why Choose Best Technology?

By reading this post, you may know how to test a PCB by multimeter already and other methods to identify them. Best Technology has engaging in the PCB manufacturing for more than 18 years, we have served over 2000+ customers all around the world. We have strong R&D team and equipped with advanced equipment to improve the yield and product quality.

At Best Technology, we provide various PCB manufacturing, including metal core PCBs, ceramic PCBs, rigid-flex PCBs and some other special PCBs like HDI PCB, busbar PCB, heavy copper PCB. If you have similiar projects, you are welcome to contact us.

Archive for the ‘HDI PCB’ Category

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Why use mcpcb for led ring light pcb

Unveiling the Components of LED PCBs

Advantages of led ring light pcb?

How does led ring light pcb dissipate heat?

How to make a LED light circuit board?

Capabilities of led ring light pcb?

Applications of led ring light pcb?

FAQs About led ring light pcb

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