Apex regulator PCB, as a key electronic component, plays an indispensable role in ensuring power supply stability. In today’s era of high digitalization and electronic equipment dependence, a stable power supply is essential for the normal operation of various devices.
What is a regulator PCB?
Regulator PCB (Printed Circuit Board) is a printed circuit board that integrates regulator-related circuit components. It is centered on regulator components (such as voltage, current or power regulators), supplemented by other circuit components such as capacitors, resistors, and inductors to work together.
Through specific working principles, such as linear regulators adjust the degree of conduction, switching regulators use high-frequency switching actions and related modulation methods to achieve voltage regulation, current detection and control to achieve current regulation, and power regulation based on voltage and current regulation.
At the same time, it has output stability, can maintain output stability when the input voltage fluctuates and the load changes, and has multiple protection functions such as overvoltage, overcurrent, and overheating. It has the characteristics of flexible design of circuit structure and parameters according to needs, high integration to reduce volume, and easy installation and use.
What are the three types of regulators?
There are three main types of regulators: contact regulators, transistor regulators, and integrated circuit regulators.
Contact regulators are an earlier type of regulator, which are characterized by slow contact vibration frequency, mechanical inertia and electromagnetic inertia, resulting in low voltage regulation accuracy, easy sparking of contacts, large radio interference, poor reliability, and short life. They have now been eliminated.
Transistor regulators emerged with the development of semiconductor technology. Their advantages include high switching frequency of transistors, no sparking, high regulation accuracy, light weight, small size, long life, high reliability, and low radio wave interference. This type of regulator is now widely used in a variety of mid- and low-end models.
In addition to the advantages of transistor regulators, integrated circuit regulators also have the characteristics of ultra-small size. They are usually installed inside the generator (built-in regulators), reducing external wiring and improving cooling effects. This type of regulator is widely used in a variety of car models.
What is an apex regulator pcb?
Apex regulator is an electronic device that regulates the voltage, current or power of a power supply to meet the needs of a specific electronic device or system. And the Apex regulator PCB is the product of combining the Apex regulator with the printed circuit board (PCB) technology.
PCB is a substrate that carries electronic components and provides electrical connections. It is made of insulating material, usually glass fiber reinforced epoxy, covered with a conductive copper foil pattern. Electronic components are mounted on the PCB by soldering or other connection methods to form a complete electronic circuit.
Apex regulator PCB integrates the Apex regulator onto the PCB, achieving a more compact and efficient power regulation solution. This integrated design not only reduces the space occupied, but also improves the reliability and stability of the circuit.
What is the function of the apex regulator pcb?
Receive input voltage: The PCB receives the input voltage from the power supply, which may vary due to a variety of factors. This input voltage is usually higher or lower than the level required by the system components.
Regulate voltage: The voltage regulator on the PCB adjusts the input voltage to match the required output level. If the input voltage is too low, the regulator increases it to the appropriate level.
Stabilizes output voltage: Once the voltage is regulated, the PCB distributes it to the various components of the electronic system. A feedback control system continuously monitors the output voltage to ensure it remains stable, and makes real-time adjustments as needed to offset any fluctuations in the input voltage.
Ensures lifespan: By maintaining a stable voltage supply, the apex regulator PCB helps protect sensitive components from damage caused by voltage surges or voltage drops.
How does a apex regulator circuit work?
The working principle of an APEX regulator PCB is to convert analog signals into digital signals through an ADC conversion circuit so that electronic devices and computers can understand and process them. This process involves converting analog signals from our real world into digital signals, allowing electronic devices to recognize and process these signals.
Specifically, the ADC conversion circuit in the APEX regulator PCB is responsible for converting the input analog signal into a digital signal. The ADC (Analog-to-Digital Converter) circuit is responsible for converting continuously changing analog voltage or current signals into discrete digital signals that can be processed and analyzed by electronic devices.
ADC circuits usually consist of three main parts: sampling, quantization, and encoding. These steps convert analog signals into binary codes that computers can process.
What are the applications for apex regulator pcb?
Apex regulator PCB is mainly used in automation industry, industrial robots, medical inspection, precision testing instruments and other fields. These application fields have high requirements for accuracy, efficiency and stability, making Apex regulator PCB an ideal choice.
In the automation industry, Apex regulator PCB is widely used in various automation equipment, such as servo system-controlled CNC trademark printing machines, CNC pipe bending machines, etc. These equipment require high-precision speed control and stable output. Apex regulator PCB can provide precise control and reliable performance to meet the needs of automated production.
In the field of industrial robots, Apex regulator PCB is used to control various actions of the robot to ensure its precise operation in complex environments. Its high torque output and stable accuracy enable the robot to perform well in various industrial applications, improving production efficiency and product quality.
Medical inspection and precision testing instruments also require regulators with high accuracy and stability. The application of Apex regulator PCB in these fields can provide precise control signals to ensure the accuracy and reliability of test results.
Conclusion:
As an indispensable part of electronic equipment, Apex regulator PCB plays an irreplaceable role in ensuring stable operation of equipment and improving equipment performance. With the continuous development of technology, it will continue to develop in the direction of miniaturization, integration, high efficiency, intelligence, etc., and continue to play an important role.
PCB beveler is a less well-known but very important tool, but it plays a vital role in the manufacturing and assembly process of PCB (printed circuit board). It is a tool specifically used to create bevels or chamfers around the edges or holes of PCB.
What is a PCB Beveler?
PCB beveler is a device used to bevel (chamfer) the edges of printed circuit boards (PCBs). Its functions include improving the electrical performance of PCBs, dispersing the electric field through beveling, reducing the risk of electrical breakdown; enhancing the mechanical properties of PCBs, preventing stress concentration and cracking at the edges; facilitating subsequent processing and assembly work, avoiding scratching other electronic components or damaging component pins during the plug-in process.
It has the advantages of high precision, high efficiency, low noise, and low energy consumption. It is widely used in the electronics industry, especially in the production process of consumer electronic products such as smartphones and tablets, which can improve production efficiency and product quality.
What is Edge Bevel in PCB?
Edge bevel is the process of making a transition edge between two sides of a PCB, usually on the outer edge of the PCB. Bevel is often used for edge connectors to allow for smoother insertion into another circuit board socket. Edge connector pins are often called gold fingers because they are plated with gold and have multiple parallel groups together.
Why do PCB edges need to be beveled?
The main reason why PCB edges need to be beveled is to increase the contact area, reduce contact resistance, and improve the stability of electrical connections.
The bevel process increases the contact area between the gold finger and other connectors by processing the PCB edge into a bevel, thereby reducing the contact resistance and improving the stability and reliability of signal transmission.
Specifically, the bevel process has the following advantages in application:
Increase contact area: Beveled edges can increase the contact area between the gold finger and the socket, thereby increasing friction and connection stability.
Reduce contact resistance: The bevel design reduces the pressure concentration at the contact point, thereby reducing the contact resistance and reducing the loss in signal transmission.
Adapt to different application scenarios: According to the specific application scenarios and equipment requirements, the bevel angle can be adjusted between 15° and 45° to meet different spatial layouts and electrical connection requirements.
The use of PCB beveling machines further improves the accuracy and efficiency of the beveling process. This mechanical equipment can accurately control the bevel angle through a high-precision mechanical transmission system and an efficient grinding process to ensure processing quality and production efficiency.
What are the Benefits of PCB Edge Beveling?
The main benefits of PCB edge beveling include enhanced aesthetics, easy installation, improved electrical performance, and reduced mechanical stress.
First, the beveling process can enhance the aesthetics of the circuit board. By cutting the PCB edge at a specific angle, the beveling process makes the appearance of the circuit board more refined and beautiful, which can significantly improve the overall visual effect of the product.
Secondly, the beveling process is easy to install. The beveling design can better adapt to the structural design of various electronic devices, making the assembly of PCB boards and other components more convenient and precise, and the design of the beveling angle can better achieve the coordination of PCB boards with other components.
In addition, the beveling process can also improve electrical performance. Bevel design can increase the contact area and reduce the contact resistance, thereby improving the stability and reliability of signal transmission.
Finally, bevel design can reduce mechanical stress. The design of the beveled rectangle allows the socket to slowly and gradually enter or exit the jack when plugging and unplugging, thereby reducing the mechanical stress during plugging and unplugging and extending the service life of the socket and jack.
What are the limitations of PCB edge beveling?
The main limitations of PCB edge beveling include the design of the bevel angle, the spacing requirements between the components and the board edge, and the requirements for cutting accuracy and speed.
First, the design of the bevel angle needs to be determined according to the specific application scenario and equipment requirements. The common bevel angle range is between 15° and 45°.
In some devices with high requirements for plugging and unplugging force and contact stability, a smaller bevel angle may be selected to increase the contact area and friction between the gold finger and the socket to ensure the stability of signal transmission; while in some occasions with strict restrictions on spatial layout, a larger bevel angle may be used to better realize the assembly of PCB boards and other components.
Finally, cutting accuracy and speed are also important limiting factors. PCB beveling machines need to have high-precision cutting capabilities and be able to accurately cut within the specified size range. The cutting accuracy directly affects the quality and reliability of the circuit board.
How Does PCB Beveling Work?
PCB beveling machines are usually composed of a frame, a transmission system, a grinding system, a positioning fixture, and a protective device.
The transmission system uses high-precision gears or screw drives to ensure processing accuracy. The grinding system consists of a grinding head and a coolant system, etc., which are used to grind PCB boards. The positioning fixture is used to fix the PCB board to ensure the accuracy and stability of the processing, while the protective device is to protect the safety of the operator.
During the operation, first check whether the beveling machine is operating normally. If there is a problem, it needs to be repaired. Then, set the beveling angle according to customer needs or the default 45° angle.
Next, adjust the angle of the gong section and the table, adjust the distance of the steel plate according to the thickness of the board, and use a copper plate of the same thickness to test the knife to ensure that the angle of the bevel of the beveled board meets the requirements.
Finally, the grinding process is carried out through the grinding system. The grinding head rotates at a high speed and applies a certain amount of pressure on the PCB board, thereby processing its edge into a bevel.
What are the Applications of PCB Beveling?
The core application of the PCB beveling process is to increase the contact area and reduce the contact resistance, thereby improving the stability and efficiency of the connection. This process is common in the beveling of gold fingers, especially on devices such as computer memory bars and graphics cards. The bevel design of gold fingers can significantly improve the data transmission speed and reliability.
Specific application scenarios include:
Computer memory bars and graphics cards: On these components, the bevel design of gold fingers can not only increase the contact area and reduce the contact resistance, but also prevent oxidation to a certain extent and extend the service life.
Other communication equipment: In addition to computer memory bars and graphics cards, the beveling process of gold fingers is also used in various devices that communicate through digital signals, such as consumer electronics, smartphones, and smart watches.
In short, the beveler in PCB is a tool specifically used to create bevels or chamfers around the edges or holes of PCBs. It has the functions of improving the reliability of PCB, facilitating assembly and improving appearance. When using the bevel, pay attention to the correct operation method and maintenance to ensure its normal operation and service life.
PCB solder plays a vital role in the assembly and function of PCBs. Reliable solder joints must remain intact to prevent components from loosening or falling off the PCB. Solder is the material used to connect the various electronic components on the PCB. Its importance is reflected in several key aspects. Solder ensures that electronic components can be firmly attached to the PCB.
What type of solder for PCB?
The commonly used types of solder for PCB include solder paste, tin bar and tin wire.
1. Solder paste: Mainly used in reflow soldering process. Solder paste consists of tin powder, flux and other additives. Tin powder is usually an alloy of tin and other metals. According to different melting points, solder paste can be divided into three types: low temperature, medium temperature and high temperature; according to different lead content, it can be divided into lead solder paste and lead-free solder paste. Lead-free solder paste gradually replaces lead solder paste to reduce environmental pollution.
2. Solder bar: Mainly used in wave soldering process. Tin bar (solder bar) has excellent antioxidant ability, good fluidity after melting, suitable for wave soldering process, and is widely used in PCBA processing due to its good fluidity and strong solderability.
3. Tin wire: Mainly used in post-soldering process. Similar to tin bar, tin wire is also a kind of welding material, mainly used for manual welding or other occasions where filament solder is required.
In addition, the selection of welding materials also involves the selection of solder alloys. Eutectic alloys are one of the preferred solder alloys because of their low melting point, low welding temperature, small crystal grains, and dense structure, which are conducive to improving the strength of solder joints.
What temperature should solder be for PCB?
The solder temperature of PCB should vary according to different types of components and welding processes.
For lead-containing PCB boards, the temperature in the preheating stage is usually controlled at 80~120℃ for 1~3 minutes; the temperature in the insulation stage is 150~180℃ for 30~60 seconds; the temperature in the reflow stage is 210~240℃ for 20~40 seconds; the cooling stage speed should be controlled within the range of 4~6℃ per second.
For lead-free PCB boards, the temperature in the preheating stage is usually controlled at 100~150℃, the insulation stage is 180~220℃, the reflow stage is 240~260℃, and the cooling speed should be controlled within the range of 3~5℃ per second.
What is the best soldering temperature for PCB?
The best soldering temperature range for PCB is usually between 240 and 280 degrees Celsius. This temperature range is suitable for manual soldering and can ensure the best soldering effect and component reliability.
For different types of welding situations, the temperature requirements are different:
1. Wave soldering: The optimal temperature is 280 degrees Celsius, ensuring that the solder joint temperature is 50 degrees Celsius higher than the melting point of the solder to achieve reliable welding results.
2. Small components (such as resistors and capacitors below 1206, and components with an area of less than 5 mm²): The recommended temperature is 250 degrees Celsius to prevent damage to the circuit board.
3. Large components: The soldering iron temperature should be set between 350 and 370 degrees Celsius, and the maximum should not exceed 390 degrees Celsius. The welding time should be kept within a few seconds to prevent damage to the pads on the PCB.
4. SMT processing: The recommended manual soldering temperature range is 240 to 280 degrees Celsius. Try to minimize the gap between the set temperature and the actual working temperature to achieve the best welding effect and component reliability.
In addition, the precise management of temperature during the welding process is also required to ensure the quality of the solder joints and circuit performance of the PCB board.
The preheating stage is very important to reduce the thermal shock during welding. The preheating temperature is usually controlled between 80 and 120 degrees Celsius for 1 to 3 minutes.
The insulation stage is to fully melt the components and solder paste on the PCB board. The temperature is usually controlled between 150 and 180 degrees Celsius for 30 to 60 seconds.
The cooling stage is to avoid thermal stress caused by rapid cooling. The cooling rate should be controlled to drop between 4 and 6 degrees Celsius per second.
What temperature does PCB solder melt?
The melting temperature of PCB solder depends on the type of solder. The melting temperature of lead solder ranges from 183°C to 217°C, while the melting temperature of lead-free solder is usually between 217°C and 257°C.
Lead solder has a lower melting point, usually between 183°C and 217°C. During the reflow process, the preheating temperature of lead solder is controlled at 80°C to 120°C, the holding temperature is 150°C to 180°C, the reflow temperature is 210°C to 240°C, and the cooling rate decreases by 4°C to 6°C per second.
The melting point of lead-free solder is higher, usually between 217°C and 257°C. During the reflow process, the preheating temperature of lead-free solder is controlled at 100°C to 150°C, the holding temperature is 180°C to 220°C, the reflow temperature is 240°C to 260°C, and the cooling rate decreases by 3°C to 5°C per second.
What is the melting point of PCB material?
The melting point of PCB material depends on its specific composition and type, usually between 1064℃ and 900℃. For PCB substrate materials, such as FR-4, its temperature resistance is measured by the Tg value (glass transition temperature). Ordinary FR-4 sheets have lower heat resistance, while high TG FR-4 sheets have better heat resistance and can withstand higher temperatures.
Different types of PCB materials have different melting points and heat resistance. The long-term working temperature of ordinary FR-4 sheets is generally between 130℃ and 140℃, and the instantaneous temperature resistance can reach 150℃ to 260℃. In contrast, PCBs made of special materials such as polyimide can withstand higher temperatures, even up to 280℃.
In addition, the surface treatment layer material of the PCB will also affect its heat resistance. For example, the melting point of the gold plating layer depends on the composition of the metal material used.
Which solder is best for PCB?
Choosing a solder suitable for PCB requires comprehensive consideration of multiple factors. The following solders have their own advantages and disadvantages:
Tin-silver-copper (SAC) alloy: good mechanical and electrical properties, high reliability, suitable for a variety of welding processes, and environmentally friendly. But the cost is high and the welding process requirements are high.
Tin-copper (Sn-Cu) alloy: low cost, good solderability, and environmentally friendly. The disadvantage is that the mechanical properties are slightly worse in high-demand scenarios.
What type of solder should not be used with electronics?
Electronic products should not use strong alkali, rosin grease, coconut oil, and neutral flux as flux.
In the soldering process of electronic products, it is very important to choose a suitable flux. The main function of the flux is to remove the oxide film, prevent oxidation, and improve the quality of soldering.
However, some substances are not suitable for use as flux. Strong alkali and rosin grease will corrode the soldering joint and affect the quality of soldering. In addition, the use of acidic flux will also corrode the soldering joint, so acidic flux should be avoided.
In order to ensure the smooth progress of the soldering process and ensure the quality of soldering, some measures can be taken.
First, choose lead-free solder materials that meet ROHS standards to reduce environmental pollution. Second, use high-brightness soldering iron tips, reduce the use of soldering oil and rosin, and reduce smoke generation. Finally, select appropriate welding materials and processes according to specific needs, such as solder wire, solder paste, solder sheet, etc., to ensure the mechanical and electrical performance of welding.
In short, solder is a key element in the PCB assembly process. Its quality is directly related to whether the electronic equipment can operate normally, and the characteristic of solder melting point plays a decisive role in the welding process. I must deeply study and understand the characteristics of solder to ensure that every solder joint can meet the highest standards.
Can you use AC in PCB?AC can be used in PCB boards. PCB boards are designed to support the use of AC, and the functions of AC can be realized through proper circuit design and component selection.
Can you use AC in PCB?
The use of AC in PCB boards requires consideration of the characteristics of AC. The current magnitude and direction of AC change continuously over time, which requires the components and layout on the PCB to adapt to such changes. For example, components such as inductors and capacitors play an important role in AC circuits, and their parameters and layout need to be carefully designed to achieve the desired circuit performance.
Specifically, AC circuit design on PCB boards includes selecting appropriate components, layout, and routing. For example, using test instruments such as LCR digital bridges can measure the parameters of components in AC circuits to ensure that the performance of the circuit meets the design requirements. In addition, reasonable ground routing and layout can reduce signal interference and ensure the stable transmission of AC.
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
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.
Aluminum is ubiquitous in all kinds of materials in daily life. The thermal conductivity of aluminum plays a very critical role in the wide application of aluminum materials. Whether it is to help electronic devices dissipate heat or to play the advantages of thermal conduction in fields such as automobiles and buildings, the thermal conductivity of aluminum must be considered.
How good is aluminum at conducting heat?
Aluminum has relatively good thermal conductivity, but its thermal conductivity is not as good as copper. The thermal conductivity of aluminum is about 237 W/m·K, while the thermal conductivity of copper is about 385 W/m·K, which means that under the same conditions, copper can transfer heat more efficiently.
The reason why aluminum has good thermal conductivity is that its thermal conductivity is high, and aluminum has a high specific heat capacity. Specific heat capacity refers to the amount of heat that needs to be absorbed or released by a unit mass of a substance to increase or decrease the temperature by 1K. Aluminum’s high specific heat capacity makes it more efficient in absorbing and releasing heat, which is crucial for applications that need to dissipate heat quickly.
What is thermal conductivity?
Thermal conductivity is a physical quantity that represents the ability of a material to conduct heat. The higher the thermal conductivity, the less heat is lost within the material. Thermal conductivity is defined as the amount of heat directly conducted through a material per unit cross-section and length per unit temperature difference and per unit time, and is expressed in Watts per meter Kelvin (W/m-K).
What is the thermal heat conductivity of aluminium?
The thermal conductivity of aluminium is 237W/mK. Thermal conductivity (k) is a measure of the ability of heat to flow through a material.
Thermal conductivity (k) is a measure of the ability of a material to conduct heat, and represents the amount of heat flow through a unit area per unit temperature gradient per unit time. Aluminium, as a common metal material, has a high thermal conductivity and is suitable for applications that require good thermal conductivity.
What is the thermal conductivity of aluminium at high temperatures?
The thermal conductivity of aluminium changes as the temperature increases. Generally speaking, as a metal gets hotter, its thermal conductivity decreases slightly. For aluminium, the thermal conductivity decreases as the temperature increases, but it still retains significant thermal conductivity.
As temperatures approach 500°C, the thermal conductivity of aluminum drops to about 160 W/m·K. This drop occurs because increasing temperatures cause increased atomic vibrations within the metal, which interferes with the flow of heat. Despite this drop in thermal conductivity, aluminum still performs well in high-temperature applications, such as engines or high-performance electronics.
What is the weight constant of aluminum?
The weight constant of aluminum is 2.7 g/cm³. Aluminum is a metallic element with a silvery-white appearance and is a lightweight metal.
The density of aluminum can also be expressed as 2.7×10³ kg/m³, which means that there are 2.7×10³ kg per cubic meter of aluminum. 34 In addition, the density of aluminum can also be expressed as 2700 kg/m³, which is another common unit conversion method.
What is the K value of aluminum?
The “K” value is a shorthand term that is often used to refer to the thermal conductivity of a material. The thermal conductivity K value of aluminum is 237 W/mK. Aluminum is a common metal material with a thermal conductivity of 237W/mK in the solid state.
Thermal conductivity (thermal conductivity coefficient) is a physical property of a material that indicates the ability of heat to be conducted through a unit area and temperature gradient in a unit time. The greater the thermal conductivity, the better the thermal conductivity of the material. Aluminum, as an excellent thermal conductive material, is widely used in many applications.
What would a high value of K mean thermal conductivity?
A high K value means that the thermal conductivity of the material is high, that is, the material has a strong ability to conduct heat. Thermal conductivity (K value) is an important parameter to measure the rate and ability of a material to conduct heat. Materials with high K values can conduct heat more efficiently and have better thermal conductivity.
Specifically, thermal conductivity (K value) is defined as the amount of heat directly conducted by a material of unit cross-section and length under unit temperature difference and unit time. The metric unit is watt/meter Kelvin (W/m·K). If the K value of a material is 1, it means that when the temperature difference between the opposite surfaces is 1 degree, 1 cubic meter of the material will conduct heat at a rate of 1 watt.
Materials with high K values have significant advantages in thermal management. First, they can quickly transfer heat from the heat source to the heat sink, effectively reducing the operating temperature of electronic components, extending the life of the device, and improving system reliability. Second, materials with high K values can significantly reduce the thermal resistance between thermal interfaces and improve the efficiency of heat transfer, especially for high power density devices. Finally, in harsh working environments, materials with high K values can significantly enhance thermal management capabilities, prevent local overheating, and ensure stable system operation.
Is a higher or lower k value better?
Generally speaking, for applications that require effective conduction or heat dissipation, the higher the K value, the better. If the material has a higher K value, it can transfer heat away from hot spots faster, helping to prevent overheating.
In the electronics industry, components can get very hot, so people use materials with high thermal conductivity to make heat sinks. These materials can draw heat away from delicate parts, helping to prevent component damage or failure.
However, in some cases, the lower the thermal conductivity, the better. In insulating materials, you want a lower K value so that heat can’t pass through easily. In these cases, materials such as plastic or fiberglass, which have much lower thermal conductivity than aluminum, are preferred.
Conclusion:
With the continuous advancement of science and technology, the understanding and application of aluminum’s thermal conductivity will continue to expand and deepen. New processing technologies may further optimize aluminum’s thermal conductivity, allowing it to play a unique role in more emerging fields, such as new energy development and high-speed rail transportation.
High density interconnect (HDI) technology plays a pivotal role in the electronics field, and high-density interconnect boards are the core embodiment of this technology. As a key connection carrier between electronic components, it is an important guarantee for realizing miniaturization, high performance and multi-functionality of electronic equipment.
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.
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.
Board electronics with holes The types of vias in PCB include through holes, blind holes and buried holes, which have different characteristics and requirements in design and manufacturing. The selection of the appropriate via type should consider the number of PCB layers, wiring density, signal frequency, cost budget and production process. The via design should pay attention to avoid affecting the welding quality, preventing electrical short circuits, and saving costs in high-density packaging.
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.
Best is mainly engaged in the production of High frequency pcb communication circuits, high-speed, microwave and radio frequency printed circuit boards, mainly in sample making and small and medium batches. The main products are: microwave radio frequency high-frequency boards, Rogers high-frequency boards, Rogers multi-layer high-frequency mixed-pressure boards, Rogers radio frequency boards, Taconic microwave boards, Taconic multi-layer circuit boards, Arlon microstrip antenna boards, ARLON high-frequency boards, F4BM antenna boards, F4BM multi-layer mixed-pressure boards, radio frequency amplifier PCB boards, HDI precision multi-layer boards, serving domestic and foreign high-tech enterprises and scientific research institutions.
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 an alumina circuit board? As a unique circuit board material, it is emerging in the electronics field with its excellent performance and advantages. It uses alumina as the main material, bringing new opportunities for performance improvement and miniaturization of various electronic devices.
What is an alumina circuit board?
Alumina circuit board is a circuit board that uses alumina ceramic as a substrate. This circuit board has excellent electrical insulation properties, high thermal conductivity, excellent soft solderability and high adhesion strength. It can be etched with various graphics like a PCB board and has a large current carrying capacity.
Alumina ceramic circuit board is an ultra-thin composite substrate made by bonding copper foil directly to the surface (single or double sides) of an alumina (Al2O3) ceramic substrate at high temperature through a special process.
Alumina ceramic circuit boards are widely used in electronic devices that require high performance and high reliability, such as solar applications, voltage regulators, amplifier circuits, and memory modules.
Alumina ceramic substrates are mainly composed of white amorphous powder, commonly known as alumina or simply Al2O3. It has excellent properties, such as high wear resistance, acid and alkali corrosion resistance, excellent performance at high temperatures (1600-1700 degrees Celsius), etc.
What types of alumina circuit boards are there?
Ordinary alumina ceramics are classified according to their Al2O3 content, including 99%, 96%, etc. 99% alumina has high purity, white or ivory color, and is widely used in various applications, including lamps, electronic devices, and wear-resistant components. 96% alumina is widely used in various electronic applications while providing good thermal conductivity and insulation properties.
96% alumina:
Suitable for thick film circuit substrates, with excellent electrical insulation properties, mechanical strength, good thermal conductivity, chemical durability and dimensional stability.
Its surface roughness is generally 0.2~0.6μm, and the maximum operating temperature of the substrate can reach 1600℃.
96% alumina has become an economical choice for manufacturing hybrid microelectronic circuits due to its availability, low cost and technical quality.
99% Alumina:
Commonly used for most thin-film electronic substrate applications such as sputtering, evaporation, and chemical vapor deposition of metals for circuit generation.
99% Alumina has higher purity, smaller grain size, and the prepared substrate has excellent surface smoothness (surface roughness is generally 0.08~0.1μm), and the maximum use temperature of the substrate can reach 1700℃.
It has high mechanical strength, low thermal conductivity, excellent electrical insulation, good dielectric properties, and good corrosion resistance and wear resistance.
What are the advantages of alumina circuit boards?
The advantages of alumina circuit boards are mainly reflected in their physical and chemical properties, which make them widely used in many fields.
High hardness: The hardness of alumina ceramic plates is very high, second only to diamond and sapphire, and has excellent wear resistance and corrosion resistance.
High melting point: The melting point of alumina is as high as 2072℃, which means that alumina circuit boards can work for a long time in high temperature environments without being affected and maintain stable performance.
Good insulation performance: Alumina ceramic boards have good insulation performance and can effectively isolate the conduction of current and heat.
Excellent heat dissipation performance: In LED lighting and high-power electronic devices, alumina circuit boards are widely used due to their excellent heat dissipation performance.
Lightweight: Compared with other materials, alumina ceramic boards have a lower density and lighter weight, which can greatly reduce the load of the equipment.
Chemical stability: Alumina is an electrical insulating material with high resistivity, good chemical stability and good corrosion resistance.
What are the disadvantages of alumina circuit boards?
The disadvantages of alumina ceramic PCBs mainly include high cost, fragility, inferior thermal conductivity to other materials, complex manufacturing process and high price.
High cost: Compared with plastic packaging, alumina ceramic PCBs have higher process temperature requirements, which leads to relatively high costs.
Fragile: Alumina ceramics are relatively fragile, and compared with aluminum nitride ceramic substrates, alumina ceramics are more fragile.
Thermal conductivity is not as good as other materials: Although alumina ceramics have certain thermal conductivity, their thermal conductivity is usually between 25W and 50W, while the thermal conductivity of aluminum nitride ceramic substrates can reach 190~260W. In comparison, the thermal conductivity of alumina ceramics is poor.
Complicated manufacturing process: Due to the high hardness of alumina ceramics, mechanical processing is more difficult, which increases the cost of its precision machined parts.
Higher price: Due to the above factors, the price of alumina ceramic PCBs is usually higher, about 3~10 times that of resin PCB boards.
What are the uses of alumina circuit boards?
Alumina circuit boards are widely used and are mainly used in the following aspects:
Electronic industry: Alumina ceramic circuit boards have become the preferred material in the manufacture of electronic components such as semiconductor devices and integrated circuits due to their excellent insulation properties and high temperature resistance.
Optoelectronic industry: In the field of optoelectronics, alumina ceramic circuit boards also perform well. Due to their high optical transparency and chemical stability, they are widely used in the manufacture of optoelectronic devices such as lasers and LEDs.
Automobile Industry: In terms of automobile headlights, the popularity of high-power LED headlights has put forward higher requirements for heat dissipation performance. Alumina ceramic substrates, with their good thermal conductivity, ensure the stable operation of LED light sources and improve lighting effects and service life.
Aerospace: Alumina ceramic substrates have been widely used in key components such as aerospace devices and satellite communication equipment due to their comprehensive performance advantages.
Medical Devices: Due to their excellent physical, chemical and mechanical properties, alumina ceramic circuit boards can meet the high requirements of medical devices for materials and ensure the performance and safety of medical devices.
In summary, alumina circuit boards have been widely used in many fields due to their unique physical, chemical and mechanical properties, providing solid support for technological progress and industrial upgrading in all walks of life.
Is alumina a good electrical insulator?
Alumina PCB is a good electrical insulator.
Alumina (Al₂O₃), as a common ceramic material, has good electrical insulation, high temperature resistance and mechanical strength. Its color is usually white or light yellow, its volume density is between 3.7-3.9 g/cm³, its thermal conductivity is as high as 24 W/(m·K) or more, and its bending strength is usually between 300-400 MPa.
In addition, alumina also has a low dielectric constant and breakdown voltage, which makes it particularly suitable for high-frequency circuits and high-voltage circuits.
Therefore, alumina PCB is not only one of the most commonly used ceramic PCBs on the market because of its low price and excellent performance, but also when using alumina PCB, there is no need to add an insulating layer, which further proves its good electrical insulation.
What other ceramic PCB materials are there?
In addition to alumina ceramic PCB materials, it also includes alumina, aluminum nitride, silicon carbide, silicon nitride, zirconium oxide, etc. These materials each have unique properties and are suitable for different application scenarios.
Aluminum nitride (AlN): Aluminum nitride is also an excellent ceramic material with extremely high thermal conductivity and low expansion coefficient. It is gray in color and has a volume density between 3.33-3.35 g/cm³. The thermal conductivity of aluminum nitride is as high as 170 W/(m·K), which is several times that of traditional organic materials. The flexural strength can reach about 400-500 MPa, and it also has a low dielectric constant, which is suitable for high-power electronic devices and high-speed digital circuits.
Silicon Carbide (SiC): Silicon carbide is a hard material with excellent wear resistance and corrosion resistance. It is gray in color and has a volume density of 3.1-3.15 g/cm³. Silicon carbide has a high thermal conductivity of up to 100 W/(m·K), a flexural strength of more than 450 MPa, and a low dielectric constant and breakdown voltage, which is suitable for power electronic devices in high temperature environments.
Silicon Nitride (Si3N4): Silicon nitride is a high-strength, high-toughness ceramic material widely used in the aerospace field. It is gray in color and has a volume density of about 3.22 g/cm³. Silicon nitride has a high thermal conductivity of up to 20 W/(m·K), a flexural strength of generally between 700-1200 MPa, and a low dielectric constant and breakdown voltage, which makes it suitable for electronic components in high temperature and high pressure environments.
Zirconium oxide (ZrO2): Zirconium oxide is a high-toughness, high-hardness ceramic material with good chemical stability. It is gray in color and has a volume density of about 6.0 g/cm³. Zirconium oxide has a high thermal conductivity of up to 3 W/(m·K), a flexural strength of about 100-400 MPa, and a low dielectric constant and breakdown voltage, which makes it suitable for electronic components in high temperature and high pressure environments.
In short, alumina ceramic PCBs are increasingly used in the electronic field. It not only provides a solid foundation for the innovative development of electronic equipment, but also opens up a new path for the advancement of future electronic technology. BEST Technology is a professional ceramic circuit board manufacturer with rich manufacturing experience in various ceramic materials, and its product quality has passed relevant quality inspections. Choosing us will get the best quality products!
Copper can be said to be an indispensable element in printed circuit boards. In printed circuit boards, copper is used as a conductive line to connect electronic components and realize the function of the circuit. Compared with other conductive materials, copper has a lower resistance, which can reduce the loss of electric energy and improve the efficiency of electronic equipment.
Why is copper used in printed circuit boards?
The main reason for using copper in printed circuit boards is that copper has good conductivity, which can greatly improve the conductivity of the circuit board and ensure that the connection between various components is more stable and reliable.
In addition, copper foil itself has high mechanical strength and stability, which can effectively prevent the printed circuit board from being damaged or deformed by the external environment.
In terms of high-frequency signal transmission, copper plating can effectively improve the conductor characteristics and impedance matching characteristics of the circuit board, protect the circuit board from oxidation or corrosion, thereby extending the service life of the circuit board and ensuring its stability and reliability.
Copper plating can reduce the voltage drop in the circuit, thereby improving the efficiency of power supply. In addition, copper plating can also enhance the mechanical strength of the PCB, so that it will not deform as much as possible during the welding process, improve the yield rate in the production process, and reduce circuit failures caused by deformation.
However, copper plating also has its disadvantages. For example, when soldering or repairing PCB samples, it may cause difficulty in replacing devices due to excessive heat dissipation, especially in the case of large devices. In addition, in RF circuits, copper plating may cause impedance mutation of the antenna, seriously affecting signal transmission.
How thick is the copper on a printed circuit board?
The thickness of copper foil on a printed circuit board is usually between 18μm and 70μm, but the specific thickness depends on the purpose of the circuit board, the voltage and current of the signal.
The most commonly used copper foil thickness is 35μm, because the copper foil thickness of 35μm is suitable for most application scenarios. However, for applications that need to carry higher power or higher current, such as high-power LED lights, power supply circuits, etc., 2OZ (about 70μm) or thicker copper foil may be selected to ensure the performance of the circuit board and the reliability and stability of electronic products.
In addition, the copper thickness of the circuit board is also affected by the thickness of its substrate. For example, the composite copper foil thickness on a substrate less than 1mm thick is about 18μm, while a copper foil thickness of 55μm may be used on a substrate greater than 5mm.
How do you choose PCB copper thickness?
When choosing PCB copper thickness, you need to consider multiple factors to ensure the performance, cost and production feasibility of the circuit board.
Application scenarios of circuit boards: For applications that need to carry high power or high current, you may need to choose thicker copper foil to ensure the stability and reliability of the circuit board. For general signal transmission, 1oz copper thickness is usually sufficient.
Number of layers and design of circuit boards: The inner layer of multilayer boards generally uses 1/2oz and 1/3oz copper thickness, while the outer layer uses 1oz or 1/2oz copper thickness.
Cost and process requirements: The thicker the copper foil, the higher the production cost. Therefore, it is necessary to consider cost factors while ensuring performance.
Special requirements: In some special application scenarios, such as when the circuit board needs to dissipate heat, copper foil with higher thermal conductivity should be selected to enhance the heat dissipation capacity of the circuit board.
What is the difference between 1 oz and 2 oz copper PCB?
The main difference between 1 oz and 2 oz copper PCB lies in the thickness of the copper foil and the current load it can withstand.
Copper foil thickness: 1 oz copper thickness refers to 1 ounce of copper per square foot on the circuit board, while 2 oz copper thickness refers to 2 ounces of copper per square foot.
Application scenario: 1 oz copper thickness PCB is the most common standard and is suitable for most application scenarios. 2 oz copper thickness is suitable for application scenarios that need to carry higher power or higher current.
Electrical performance and heat dissipation performance: In theory, thicker copper foil can directly reduce the ground resistance by half, and the number of joules of heat generated per unit time during operation will also be reduced accordingly. At the same time, it can more effectively shield the electromagnetic interference between components and wires.
How thick is the copper on a 1 ounce copper PCB?
The copper thickness of 1 ounce copper on a PCB is about 35 microns.
In PCB design and processing, the copper thickness is often expressed in ounces (oz) as a unit. Specifically, the thickness of 1 ounce of copper is about 35 microns, which is equivalent to 1.4 mils. Although this method of expression uses the weight unit ounce, it actually indirectly expresses the average thickness of the copper foil through the weight per unit area.
In the PCB industry, ounces are not only a unit of weight, but also used to express the thickness of copper foil, where 1oz means the thickness of 1 ounce of copper evenly laid on an area of 1 square foot. This method of expression is very common in the fields of electronic engineering and circuit board manufacturing to ensure that the conductivity and current carrying capacity of the circuit board meet the design requirements.
Which metals Cannot be used in printed circuit boards?
In the production of printed circuit boards, some metals are usually not used.
First of all, iron has poor conductivity and cannot meet the requirements of printed circuit boards for good conductive materials. Moreover, iron is easy to rust, which will affect the appearance of the circuit board and may also cause circuit short circuits or poor contact.
Lead is also not suitable for printed circuit boards. On the one hand, lead is a toxic heavy metal. With the improvement of environmental protection requirements, the use of lead-containing materials in the electronics industry is limited, and lead-containing solder in printed circuit boards has gradually been replaced by lead-free solder. On the other hand, lead has poor mechanical properties, low hardness and easy deformation, which may deform or damage the circuit board during manufacturing and use.
Mercury cannot be used in printed circuit boards. Mercury is extremely toxic and has serious harm to the human nervous system, immune system, etc. At the same time, mercury is liquid and volatile at room temperature, difficult to control, easy to cause leakage and pollution, and its conductivity is not ideal.
Although gold has advantages such as good conductivity, corrosion resistance and oxidation resistance, its cost is too high and it is not suitable for large-scale application in printed circuit boards. In addition, gold has low hardness and is easily scratched or worn, affecting the performance and reliability of the circuit board.
What is the major disadvantage of printed circuit boards?
The major disadvantages of printed circuit boards include disposable boards, environmental impact of etching, and compatibility issues.
Disposable boards: Printed circuit boards are designed with one-time use in mind, which means that if the circuit board needs to be modified after printing, it will not be possible and a new board needs to be created from scratch.
Environmental impact of etching: The chemicals used in the etching process have a negative impact on the environment. Although the etching process is very effective for circuit board production, it is not environmentally friendly.
Compatibility issues: Before starting to make a circuit board, you need to determine the device you are designing for, which increases the complexity and potential risks of the design.
These shortcomings limit the use of printed circuit boards in some applications to a certain extent, especially in scenarios that require high customization or frequent modifications.
In short, copper printed circuit boards occupy an irreplaceable position in the electronics field with their excellent performance. From consumer electronics to communications, automotive electronics, and industrial control, it can be seen everywhere. Copper’s high electrical conductivity, good thermal conductivity, and strong machinability make it a key link connecting the electronic world.
