Archive for the ‘SMT Technology’ Category

What is the body to body clearance for smt parts?

Wednesday, September 11th, 2024

Surface Mount Technology (SMT) has revolutionized electronics manufacturing, allowing for compact, efficient, and high-speed production of printed circuit boards (PCBs).

But designing an effective PCB requires an understanding of critical clearance rules, especially when dealing with SMT components. Proper body-to-body clearance can influence reliability, manufacturability, and long-term performance.

What Is the Clearance Rule for PCB?

PCB design follows strict clearance rules to ensure that components work as expected. Clearance refers to the minimum space required between elements on the board to prevent interference, short circuits, or damage during soldering and operation.

What is the body to body clearance for smt parts？

The general clearance rules for PCBs depend on factors such as voltage, current, and operational environment. For standard PCBs, a common clearance rule is 0.1 mm to 0.2 mm between components, though this can vary based on specific needs. It’s essential to consult design guidelines from the PCB manufacturer, as they may provide specific instructions based on their capabilities.

How Close Can Components Be on a PCB?

Component spacing is one of the most crucial elements in PCB design. The minimum distance between SMT parts, or body-to-body clearance, is influenced by several factors, including component size, heat dissipation, and soldering methods.

For standard designs, a minimum body-to-body clearance of 0.2 mm to 0.5 mm is typical for most SMT components. This spacing ensures proper airflow, heat dissipation, and avoids accidental shorts during soldering. Smaller devices may require tighter clearances, but you should always account for potential manufacturing limitations and performance requirements.

Maintaining adequate clearance also helps with inspection and rework. If components are too close together, it becomes challenging to check for soldering defects or make repairs, increasing costs and time for revisions.

What Is the Spacing Between SMD Pads?

Surface Mount Devices (SMD) pads are small metal areas on the PCB where components are soldered. The pad spacing plays a critical role in ensuring good electrical contact while avoiding issues like bridging, where solder connects unintended pads, causing shorts.

The spacing between SMD pads is often defined by the component’s package type.

For example:

– For a 0603 package, the typical pad spacing might be around 0.8 mm.

– For a larger 1206 package, it could be around 1.5 mm or more.

In addition to pad spacing, the size of the pad must be carefully chosen to ensure that it supports the component correctly without causing issues during soldering. If the pads are too close, there is a higher chance of bridging, especially when using automated processes like reflow soldering. On the other hand, too much spacing could lead to poor contact, reducing the reliability of the connection.

What Is the Difference Between SMT and SMD Components?

SMT (Surface Mount Technology) refers to the process of mounting components directly onto the surface of a PCB. SMD (Surface Mount Device) is the term for the components themselves.

In essence:

SMT: The technology and process of assembling components on a PCB.

SMD: The individual components that are placed using SMT techniques.

The two terms are often used interchangeably, but it’s helpful to remember that SMT refers to the process, while SMD refers to the devices used in that process.

SMT has advantages over older methods like through-hole mounting, including reduced size and weight, faster production, and the ability to place components on both sides of the PCB. SMD components are designed specifically to benefit from these advantages, often smaller and lighter than their through-hole counterparts.

How Close Can PCB Traces Be?

PCB traces are the conductive pathways that connect components on the board. Proper spacing between these traces is critical to avoid electrical interference, arcing, or short circuits.

The minimum trace clearance depends on the operating voltage and current. For low-voltage circuits, traces can be closer together, but higher-voltage designs require more significant separation to avoid electrical breakdown.

For example:

– For a PCB operating at less than 100V, a typical trace clearance might be around 0.2 mm to 0.5 mm.

– For high-voltage designs (e.g., 600V), trace spacing might need to increase to 3 mm or more.

It’s essential to follow the manufacturer’s recommendations and industry standards like IPC-2221 when determining trace clearance. Additionally, wider spacing can improve performance, particularly in high-frequency circuits where issues like crosstalk become more prominent.

What Is the Edge Clearance of a PCB?

Edge clearance refers to the distance between components or traces and the outer edges of the PCB. Ensuring adequate clearance near the edges prevents damage during manufacturing and assembly. It also allows room for board routing, where mechanical tooling may cut the board from a larger panel.

The general rule for edge clearance is to keep components at least 1 mm to 2 mm away from the PCB’s edge. This gives enough room for mechanical handling, ensures that traces aren’t damaged during cutting, and reduces the risk of short circuits due to edge contact.

In designs that incorporate connectors or other mechanical features near the board’s edge, additional clearance may be necessary to accommodate mounting holes or alignment features.

Additional Considerations for SMT Clearance and Spacing

In addition to the factors already covered, there are several other considerations when designing SMT PCBs:

1. Thermal Considerations: Proper body-to-body clearance helps ensure that heat can dissipate effectively. Crowding components too closely together can lead to hot spots, reducing the life of the board and its components.

2. Automated Assembly: If you’re using automated pick-and-place machines for assembly, sufficient clearance is needed for accurate placement. Overly tight layouts can lead to assembly errors or slower production times.

3. Manufacturability: PCB fabricators have limitations on how closely they can place components, traces, and vias. These limitations vary from one manufacturer to another, so it’s essential to consult with them early in the design process to avoid issues during production.

4. Inspection and Rework: Allowing enough space between components simplifies inspection and rework. If something goes wrong during assembly, having accessible components makes repairs quicker and more cost-effective.

Practical Tips for Ensuring Proper Clearance Between PCBs

Use Design Guidelines: Always reference your PCB manufacturer’s design rules. These will give you specific guidance on spacing, trace widths, and clearances based on their capabilities.

Optimize Component Placement: Group similar components together when possible. For instance, resistors and capacitors can often be placed closer together than components that require heat dissipation.

Account for Heat Dissipation: Keep heat-generating components like power ICs and transformers farther apart from sensitive components like sensors. This minimizes heat transfer and reduces the chance of thermal stress.

Perform Electrical Testing: Simulate your design using PCB software to check for potential clearance violations, especially around high-voltage areas and traces that could experience crosstalk.

Test with Prototypes: Before full production, build a prototype to test clearance in real-world conditions. This will allow you to identify any spacing issues and resolve them before scaling production.

Conclusion:

Achieving proper body-to-body clearance for SMT parts is critical for the performance and longevity of your PCB. By following the established guidelines for component spacing, pad placement, trace clearance, and edge spacing, you can ensure that your design meets both functional and manufacturability requirements. This not only improves the reliability of your board but also reduces the likelihood of costly errors during assembly and operation.

Invest time in careful planning during the design phase to avoid unnecessary revisions later on. Working closely with your PCB manufacturer and utilizing design simulation tools can go a long way in ensuring your final product performs as expected.

In the end, understanding and applying the right clearance rules will result in a robust, reliable, and efficient PCB design that meets the demands of modern electronics.

How to remove oxidation from PCB?

The methods for removing oxides from PCBs mainly include physical cleaning, chemical cleaning, and mechanical polishing.

1. ‌Physical cleaning‌:

Use alcohol or diluent to gently wipe the oxidized part until the oxide is removed. This method is suitable for removing the surface oxide layer, but it is not suitable for situations where the metal surface circuit has been damaged.

2. ‌Chemical cleaning‌:

Use specific cleaning agents such as deionized water, isopropyl alcohol, acetone, etc. to effectively remove residues and contamination.

In addition, cleaning and corrosion using acidic solutions or oxidants is also an effective chemical method, but it must be used with caution to avoid damage to the PCB board and other components.

3. ‌Mechanical polishing‌:

Use fine sandpaper or abrasive cloth to carefully polish the oxidized area to restore the conductivity of the metal. This method is suitable for removing thicker oxide layers, but you need to control the strength to avoid damaging the pad surface.

Before any cleaning and repair, be sure to disconnect the PCB power supply to ensure safety. For cases where oxidation has damaged the metal surface circuit, conductive paint needs to be used for repair, but be aware that excessive use of conductive paint may damage the circuit board. In addition, for unused PCBs, they should be stored in sealed bags or protective agents and checked regularly to ensure that they are not oxidized again.

Is silver oxidation permanent?

Silver oxidation is not permanent. ‌

Silver oxidation is caused by the reaction of silver with chemicals such as oxygen and sulfur in the air, resulting in a black silver sulfide film on the silver surface. This oxidation reaction is one of the main reasons for the blackening of PCBs.

However, silver oxidation is not permanent, because the oxide layer can be removed by cleaning and maintenance to restore the gloss of the PCB surface. For example, regular use of professional PCB cleaners or soaking the PCB in diluted detergent water, then gently scrubbing it with a soft brush, and finally rinsing it with clean water and drying it can effectively remove the oxide layer.

In addition, avoiding contact with chemicals, keeping dry, regularly checking and properly storing PCBs are also effective ways to prevent oxidation.

Therefore, although silver oxidation is inevitable, the rate of oxidation can be slowed down through proper care and maintenance.

What is the best way to Deoxidize silver?

The best way to remove silver oxide from PCBs is to use chemical stripping, which involves using a specific chemical solution to treat the silver plating so that it dissolves in the solution to achieve the purpose of removing the oxide.

The effectiveness of this method depends on the selection of appropriate chemical formulas and operating conditions to ensure that the silver layer can be completely stripped while avoiding corrosion to the base metal.

In chemical stripping, different formulas can be used to achieve the removal of the silver layer. For example, one formula includes a mixture of concentrated sulfuric acid and concentrated nitric acid, which is used at a temperature of 80°C until the silver layer is completely stripped.

Another formula includes a mixture of sulfuric acid, nitric acid, silver chloride and potassium cyanide, which is also used at a temperature of 80°C. These formulas need to be selected according to actual conditions, and attention should be paid to safety measures during operation to prevent corrosion of the base metal.

In addition, for the oxidation problem of PCB gold fingers, although it is not exactly the same as the method of removing silver oxide, some cleaning methods are provided, such as using erasers, alcohol cleaning, decontamination paste cleaning, scrubbing board grinding and electroplating treatment, which are also suitable for treating silver oxide, especially when the oxide is relatively mild.

In summary, the best way to remove PCB silver oxide is chemical stripping, which is achieved by selecting appropriate chemical solutions and operating conditions. For more serious oxidation situations, it may be necessary to combine physical and chemical methods for cleaning.

How do you save silver from oxidation?

The methods to prevent PCB silver from oxidation mainly include the following points:

Reasonable storage and packaging ‌: During storage and transportation, PCBs should be stored in a dry, ventilated, dust-free environment to avoid moisture and corrosion. Use appropriate packaging materials, such as moisture-proof bags, foam boxes, etc., to ensure the integrity and quality of the PCB.

‌Surface treatment ‌: During the PCB surface treatment process, surface treatment methods such as gold plating and tin plating can be used to prevent oxidation.

Use anti-oxidation coating ‌: Anti-oxidation coating is an efficient and reliable method to prevent PCB oxidation. It can form a strong, corrosion-resistant protective layer on the surface of the PCB, effectively preventing the PCB from being damaged by oxidation.

Reduce contact with air and moisture‌: Make sure the gold fingers are stored in a dry environment and avoid long-term exposure or immersion in water.

‌Use a protective coating‌: Applying a protective coating on the gold fingers can help prevent oxidation. This can be done using a variety of materials, such as nickel, palladium, or a thin layer of metal‌.

‌Regular cleaning and inspection‌: Regular cleaning of the gold fingers can also help prevent oxidation. This is done using a soft brush and a cleaning solution specifically designed for PCBs‌. Check the status of the gold fingers regularly, and clean and maintain them immediately if any signs of oxidation are found‌.

What is the shelf life of immersion silver PCB?

The shelf life of immersion silver PCB is at least 12 months. ‌This shelf life is determined under proper storage conditions, that is, in a sealed package, with a temperature controlled at 22 degrees plus or minus 4 degrees, and a relative humidity of less than 70%.

Once the circuit board is taken out for use, it must be soldered within 24 hours to ensure that its quality and performance are not affected‌.

The thickness of immersion silver surface treatment is usually between 0.4 and 1 micron, and this treatment is widely used by chip manufacturers for baseline bonding, EMI shielding and metal dome contacts.

Its purpose is to provide a reliable surface treatment, ensuring that the PCB surface will not oxidize and maintain its electrical performance stability for a shelf life of 12 months according to the IPC J-STD-003 standard.

In addition, the shelf life of the circuit board is also affected by its surface treatment process. For example, the vacuum packaging storage period of immersion gold, electro-gold, and tin-spraying boards is 3 months, while the storage period after unpacking for OSP, immersion tin, and immersion silver boards is 48 hours, 72 hours, and 48 hours respectively.

This shows that immersion silver PCBs can maintain a long shelf life if they are not unpacked, but the soldering process needs to be completed as soon as possible before use to ensure their performance.

Conclusion:

Silver oxidation is a natural process, but it does not affect the performance of the PCB. The key to controlling silver oxidation is regular maintenance, proper storage, and quick action when rust occurs. It should be stored properly and coated with a protective coating when necessary.

What is Soldering?

Soldering is a PCB assembly process where two or more metal surfaces are joined by melting and flowing a filler metal (solder) into the joint. Unlike welding, soldering doesn’t melt the base metals. Instead, the filler metal, which has a lower melting point, is used to create a bond between the two surfaces. The process is common in electronics, plumbing, and metalwork, where a strong, conductive connection is needed.

Generally speaking, the commonly used solder materials are tin lead alloy solder, antimony solder, cadmium solder, silver solder, and copper solder. The linear solder used in standard welding operations is called rosin cored solder wire or solder wire. A flux was added to the solder. This flux is composed of rosin and a small amount of active agent. It is very important to set the temperature during welding operation. The most suitable temperature for welding operations is plus 50 degrees at the melting point of the welding used. The set temperature of the soldering iron head, due to the size of the welding part, the power and performance of the soldering iron, and the different types and lines of the solder, it is appropriate to increase 100 degrees on the basis of the above temperature.

The main products of solder are divided into three categories: solder wire, solder bar and solder paste. Applied to all kinds of electronic welding, suitable for manual welding, wave welding, reflow welding and other processes.

What is Soldering Primarily Used For?

Soldering is mainly used in the electronics industry to connect various components on PCBs. Without soldering, it would be nearly impossible to create the intricate electrical connections that power most electronic devices. From mobile phones to computers, soldered joints are everywhere.

Soldering is also widely used in plumbing for joining copper pipes. It creates leak-proof seals that withstand pressure, making it reliable for water supply systems. Additionally, jewelry makers and metalworkers use soldering to join fine pieces of metal. It allows them to create strong, invisible joints without damaging delicate components.

What Temperature Does Solder Melt?

The melting point of solder depends on the type of solder being used. Solder typically comes in two main varieties: leaded and lead-free.

Leaded Solder

The most common composition of leaded solder is a mixture of tin (Sn) and lead (Pb), typically in a 60/40 ratio. This type of solder melts at around 183°C (361°F). Leaded solder has been used for decades due to its reliable melting point and easy flow properties, making it ideal for electronics.

Lead-Free Solder

Lead-free solder is now more widely used due to health and environmental regulations. Lead-free solder typically contains a mix of tin, copper, and sometimes silver. Its melting point is slightly higher, around 217°C (423°F). Although it requires more heat, lead-free solder is considered safer and more environmentally friendly.

It’s important to note that different solders may have varying melting points depending on their specific composition. Always check the specifications of the solder you’re using to ensure you apply the correct temperature.

Does Solder Have Lead?

Not all solder contains lead. Leaded solder was once the standard for many years, especially in the electronics industry. However, due to the harmful effects of lead exposure, leaded solder is being phased out, particularly in consumer electronics.

Lead-free solder is now the preferred option, especially for products sold in regions that regulate the use of hazardous materials. The shift to lead-free solder has become more prevalent with the Restriction of Hazardous Substances (RoHS) directive, which bans the use of lead in many electrical and electronic products. Today, many manufacturers and companies use lead-free solder for health and environmental reasons.

While lead-free solder is generally considered safer, leaded solder is still used in some industries due to its lower melting point and reliability in certain applications.

What is the Melting Point of Solder?

The melting point of solder depends on its composition, but the most commonly used solders have predictable melting temperatures:

Leaded Solder: 183°C (361°F)

Lead-Free Solder: 217°C (423°F)

These are standard temperatures, but other specialized solders may melt at higher or lower temperatures. For instance, silver-bearing solders may melt at higher temperatures, while low-temperature solders for specific applications can melt as low as 138°C (280°F).

Knowing the exact melting point of your solder is important because using the wrong temperature can lead to poor joints or even damage to components. In electronics, overheating can affect sensitive components, while underheating can result in weak or unreliable connections.

What is Lead-Free Solder Made of?

Lead-free solder typically contains a mixture of metals designed to mimic the properties of traditional leaded solder. The most common lead-free solder composition is a mix of tin (Sn), copper (Cu), and sometimes silver (Ag). This combination ensures a solid joint while keeping the melting point manageable.

Tin (Sn): The main ingredient in most solders, providing strength and flexibility.

Copper (Cu): Helps to enhance the mechanical strength of the solder joint.

Silver (Ag): Sometimes added to improve conductivity and joint strength, though this increases cost.

Lead-free solder is used to create safer work environments, particularly in industries where workers are regularly exposed to soldering fumes. It is also more environmentally friendly as it reduces the risks associated with lead contamination.

Is Tenshan Lead-Free?

Yes, most manufacturers, including Tenshan, now offer lead-free solder options in compliance with environmental standards. Lead-free solders, like those provided by Tenshan, are designed for use in various industries, ensuring safe and effective soldering without the risks associated with lead exposure.

Lead-free products from companies like Tenshan are developed to meet both performance and safety standards. These solders deliver excellent bonding capabilities without compromising the health of the workers or the environment. With the growing emphasis on eco-friendly practices, lead-free options are becoming the preferred choice for many applications.

What does PCBA mean?

PCBA is the abbreviation of Printed Circuit Board Assembly, which refers to the process of welding, inserting, etc. of electronic components to the circuit board, and welding, inserting, etc. PCBA is an indispensable and important link in the manufacture of electronic products, which directly affects the performance stability and service life of electronic products.

The manufacturing process of PCBA mainly includes components mounting, welding, post-welding processing and functional testing. The first is the component mounting, which is a process of welding the patch components, plug-in components, etc., to the PCB. Then there is welding, through traditional wave soldering or modern lead-free welding and other methods, the components are firmly fixed on the PCB. After that, the welding process is mainly to remove the welding slag on the PCBA surface, clean the PCBA surface, and check the solder joints and components of PCBA. Finally, the functional test is carried out, which is the last step in the PCBA process, and the PCBA is fully functional tested by various test equipment to ensure the stability and reliability of PCBA.

Applications of PCBA

PCBA products are widely used in various electronic products, such as household appliances, communication equipment, automotive electronics, industrial control equipment, etc. You can see it everywhere.

Different electronic products have different requirements for PCBA. Some require PCBA to be small and exquisite, some require PCBA to be high temperature and high pressure resistant, and some require PCBA to be waterproof and dustproof. With the rapid development of 5G, artificial intelligence, Internet of Things and other fields, PCBA will be more widely used, and PCBA’s performance and reliability requirements will also be higher.

Common components on a PCBA and their symbols

1. Resistor

Resistors are one of the most commonly used electronic components in PCBA, used to limit the current in the circuit. According to different materials, structures, and resistance values, resistors can be divided into fixed resistors, variable resistors, and special resistors. Resistors are widely used in various circuits, such as power circuits, amplification circuits, signal processing circuits, etc., to achieve current regulation and control.

2. Capacitor

A capacitor is a component that stores charge and electrical energy, with the characteristic of blocking direct current and passing alternating current. In PCBA, capacitors are commonly used in circuits such as filtering, coupling, tuning, and bypassing to improve circuit performance and stability. According to their different structures and applications, capacitors can be divided into fixed capacitors, variable capacitors, and fine tuned capacitors.

3. Inductor

Inductor, also known as induction coil, has the function of storing magnetic energy. In circuits, inductors can prevent changes in current and play a role in filtering and stabilizing the current. Inductance has a wide range of applications in power filtering, signal processing, and other fields.

4. Diode

A diode is an electronic component with unidirectional conductivity, widely used in circuits such as rectification, detection, and voltage regulation. In PCBA, diodes can achieve functions such as voltage regulation, signal amplification, and switch control in the circuit. Common diodes include silicon diodes and germanium diodes, whose performance parameters such as forward voltage drop and reverse breakdown voltage determine their application scenarios.

5. Transistor

Transistors are electronic components with functions such as amplification and switching, and are the core components that make up various circuits. In PCBA, transistors are commonly used in amplification circuits, oscillation circuits, switch circuits, etc. to achieve signal amplification, frequency conversion, and circuit control. There are many types of transistors, including bipolar transistors, field-effect transistors, etc., each with its own characteristics, widely used in various electronic devices.

6. IC Integrated circuit

Integrated circuit is an electronic component that integrates multiple electronic components on a single chip, with advantages such as small size, low power consumption, and stable performance. In PCBA, integrated circuits are key components for implementing various complex functions, such as digital signal processing, analog signal processing, communication interfaces, etc. Common integrated circuits include operational amplifiers, logic gate circuits, microprocessors, etc., which are widely used in various intelligent devices and systems.

7. Sensor

Sensors can sense physical quantities or states in the environment and convert them into electrical signals for output. In PCBA, sensors are commonly used to detect parameters such as temperature, humidity, light, pressure, etc., providing data support for intelligent control of electronic devices. There are various types of sensors with different performances, and choosing the appropriate sensor is crucial for improving the performance and user experience of electronic devices.

8. Controllable silicon rectifier (SCR)

Also known as thyristors, silicon controlled rectifiers (SCR) are similar to transistors and diodes – their working principle is essentially the coordinated operation of two transistors. Although SCR also has three pins, they are composed of four layers of silicon material instead of three layers, and are only used as switches, not amplifiers. Unlike single transistors that require continuous current to remain on, SCR only requires one pulse to activate the switch. They are very suitable for converting large amounts of electricity.

9. Crystal oscillator

Crystal oscillators provide clock signals in many circuits that require precise and stable timing. By physically oscillating piezoelectric materials (such as crystals), they generate periodic electronic signals, hence their name. Each crystal oscillator is designed to vibrate at a specific frequency, which is more stable, economical, and smaller in size than other timing methods. That’s why they are commonly used for precise timing in microcontrollers, or more commonly as clock components in quartz watches.

10. Switches and relays

A basic and easily overlooked component, a switch is simply a power button that controls the current in a circuit by switching between open or closed circuits. They vary greatly in appearance, from sliders, rotations, buttons, levers, toggles, key switches, and more. Similarly, a relay is an electromagnetic switch that operates through a solenoid, acting like a temporary magnet when a current flows through it. They act as switches and amplify small currents into larger ones.

Now that you’re familiar with some basic electronic components, why not dive into creating your own electronics project? Instead of starting with a complex project featuring advanced functions, begin with a few simple ones. As with any hobby, you’ll encounter challenges along the way, but these hurdles are not insurmountable. With accessible and affordable beginner electronics tools like Arduino and CAD tools, the maker community welcomes new PCB designs and projects every day.

In addition to PCB manufacturing, Best Technology offers a full turnkey service, including parts procurement and assembly. Whether you’re working on prototypes or scaling up to mass production, Best Team provides a one-stop solution for seamless and hassle-free PCB assembly.

What Does POP Do in Assembly?

In an era where consumer electronics are becoming smaller and more powerful, saving PCB space is crucial. PoP allows for the vertical stacking of components, such as processors and memory, on top of each other. This is especially important in devices like smartphones, tablets, and wearable technology, where space is at a premium.

One of the significant advantages of PoP is the ability to individually test and replace the stacked components before final assembly. This step-by-step verification ensures higher yields during manufacturing, as defective components can be identified and replaced early in the process. Additionally, since each component is tested separately, the overall cost of assembly can be reduced, as fewer defective products reach the final stages of production.

Moreover, PoP provides manufacturers with the flexibility to mix and match different types of components. For example, different memory types can be combined with various processors, depending on the requirements of the final product.

SMT POP Structure

POP stacking assembly typically involves placing components on top of each other, usually combining logic and memory devices. The structure can range from 2 to 4 layers, with memory PoP going up to 8 layers. Although the overall height increases slightly, each component can be tested individually before assembly, ensuring higher yield rates and minimizing total assembly costs.

PCB Assembly Layers of PoP:

What is SMT POP (Package on Package) Process?

Amkor PoP Typical Structure:

Bottom PSvfBGA (Package Stackable very thin fine pitch BGA)

Top Stacked CSP (fine pitch BGA)

Bottom PSvfBGA Structure:

Dimensions: 10-15mm

Pad pitch: 0.65mm, with bottom ball pitch at 0.5mm (0.4mm)

Substrate: FR-5

Ball material: 63Sn37Pb/Pb-free

Top SCSP Structure:

Dimensions: 4-21mm

Bottom ball pitch: 0.4-0.8mm

Substrate: Polyimide

Ball material: 63Sn37Pb/Pb-free

Ball diameter: 0.25-0.46mm

SMT POP Manufacturing Process

The manufacturing process for Package on Package technology is a multi-step procedure that demands precision and careful attention to detail to ensure the successful assembly of high-performance electronic devices. Here’s an extended explanation of each stage in the PoP manufacturing process:

1. Non-PoP Side Component Assembly

The PoP process begins with the assembly of components on the non-PoP side of the PCB. This involves standard SMT assembly processes:

Stencil Printing: Solder paste is applied to the designated pads on the PCB using a stencil.

Component Placement: Using automated pick-and-place machines, surface-mount components are accurately positioned onto the solder-pasted pads.

Reflow Soldering: The PCB is then passed through a reflow oven, where the solder paste is heated to its melting point, securing the components to the board.

Inspection: The solder joints are inspected using Automated Optical Inspection (AOI) to ensure that they are correctly formed and that the components are properly placed.

2. Solder Paste Printing on the PoP Side

After completing the assembly on the non-PoP side, the PCB is flipped, and solder paste is printed on the pads where the bottom PoP component will be placed. This step is crucial, as the quality of the solder paste application directly affects the integrity of the solder joints between the PoP components.

3. Placement of Bottom Components and Other Devices

The bottom components, which typically include the logic processor, are placed onto the solder-pasted pads using high-precision pick-and-place equipment. This placement must be extremely accurate to ensure proper alignment with the top component in the subsequent steps.

4. Flux or Solder Paste Dipping for the Top Components

Before the top component is placed, it is dipped in flux or a thin layer of solder paste. This dipping ensures that the solder joints between the top and bottom components are robust and reliable. The flux helps to clean the surfaces and promote better solder flow during reflow, while the solder paste provides additional material for the solder joints.

5. Placement of Top Components

The top component, typically a memory chip, is then placed onto the bottom component. This step requires precise alignment to ensure that the solder balls on the top component correctly match the pads on the bottom component. Any misalignment can lead to defective connections and, consequently, a malfunctioning device.

6. Reflow Soldering and Inspection

Once the top component is placed, the entire assembly is subjected to reflow soldering. During this process, the PCB passes through a reflow oven where the solder paste re-melts, forming solid connections between the components. The temperature profile during reflow must be carefully controlled to prevent warping or damaging the delicate PoP structure.

After reflow, the assembly is inspected using AOI or X-ray inspection to verify the quality of the solder joints, particularly the hidden joints between the top and bottom components. X-ray inspection is often employed because it can penetrate the layers and provide a clear view of the solder joints, ensuring there are no voids, misalignments, or insufficient solder.

7. Final Testing and Quality Control

The assembled PoP structure undergoes a series of electrical tests to ensure functionality. This includes testing for continuity, shorts, and the performance of the integrated components. High-quality PoP assemblies should pass all functional tests without issue, confirming that the solder joints and component placements are reliable.

8. Packaging and Shipping

After passing the final tests, the PoP assemblies are cleaned to remove any residual flux or contaminants. They are then packaged according to the customer’s requirements and prepared for shipping. Proper packaging is essential to protect the sensitive PoP structures from damage during transit.

POP Design Considerations

Factors affecting the spatial relationship include substrate and component design, substrate manufacturing processes, component packaging processes, and SMT assembly processes. Key aspects to consider are:

Pad design
Solder mask opening
Ball size and height variation
Amount of flux or solder paste applied
Placement accuracy
Reflow environment and temperature
Warpage of components and substrate
Bottom component molding thickness

What are the advantages of POP smt process?

POP is mainly a system integration 3D package developed for mobile devices, and its structure mainly has the following characteristics.

Storage devices and logic devices can be freely combined, and can be tested or replaced separately to ensure the yield.
POP is stacked in the vertical direction, saving the board area and improving the system packaging density.
The vertical interconnection of stacked devices replaces the traditional two-dimensional package interconnection, which can realize faster data transmission between logic devices and storage devices.

With the development of technology, the following main types of POP structures have emerged.

Solder Ball Connected PoP

Logic chips have more I/0 ports, so they are often packaged with Flip Chip (FC) technology and used as the bottom component. The bottom chip adopts Capillary Under Fill (CUF) technology.

MLP Connected PoP

In order to develop a thinner PoP Package structure, MoldimgLaser Package (MLP) technology came into being, also known as Through Mold Via (TMV) technology on the market. The method is to first weld the tin ball around the bottom chip and directly plastic seal, and then use laser perforation to expose the tin ball for subsequent connection with the upper components.

Folded and BVA Connected PoP

In order to meet the requirements of thin size, strong function and large I/0 number of PoP products, flexible circuit boards are used to connect various package components and fold to form PoP structure, and BVA (Bond Via Array) is used to improve product performance and reduce pin spacing.

POP Applications

1. Smartphones: PoP is widely used in smartphones, like the Meizu 16S, for integrating application processors and memory.

2. Wearable Devices: PoP is commonly used in next-generation wearable devices.

3. Electronic Watches: PoP packaging is key for improving performance and reducing costs in electronic watches.

4. Earphones: The Meizu POP Pro noise-cancelling earphones utilize PoP technology.

5. Health Watches: Huami’s Amazfit Pop, one of the most affordable blood oxygen monitoring watches, uses PoP technology.

For more information about our POP Assembly capabilities, please contact us any time! We can be reached via email at sales@bestpcbs.com, or toll free at +86-755-2909-1601.

Usb connector types

Types of USB connectors: different types of connectors with different shapes and directions, USB connectors can be separated into different types:

Type-A port: This is the most common type of USB port, the shape is long and rectangular, and the support is heat-resistant. Computer equipment such as printing machine, keypad, mouse button, driving device, etc. Type-A interface has USB 2.0 and USB 3.0 in different editions, among which USB 3.0 has faster speed, color is usually blue, and USB 2.0 has slow speed, color is black.

Type-B contact: Type-B contact shape is round shape, demand-specific connection. For general use, external equipment such as audio equipment, viewing equipment, etc., such as a 3.5 inch movable screen, stamping machine, display device, etc.Type-B verbal usage scene is relatively small, so this is an unusual sight in daily life.

Usb connector types:Type-A port:Type-B contact

Type-C port: Type-C port is a new type of USB port that has emerged in recent years. Built-in USB 3.1, Type-C interface configuration, mainstream interface type, intelligent handheld computer, flat panel battery, notebook battery, etc. The biggest feature of the Type-C interface is its support and double-sided insertion, making it convenient and convenient to use.

Type-C interface support further improves the speed and power of the power, and provides more advanced usage experience. Previously, when I came here, I was confused as to how to get around the main machine.

Mini USB port Micro USB port

Mini USB port Micro USB port: There are many types of ports for transfer equipment, digital reading machine, digital image machine, metering equipment, etc. Mini USB port ratio Micro USB port size is small, also known as a USB port, Micro USB port is smaller, thinner, supports OTG function, and provides a number of additional power functions. The Micro USB port is convenient and easy to use, and has various types of portability.

What functions does USB have?

Power Delivery of USB Ports
Some USB cables can deliver power as well as transfer data, but most USB cables can do both. Power delivery of USB ports is mainly divided into three categories: fast charging, quick charging, and power only.
USB Data Transfer Speed
USBs come in various sizes and shapes. Also, USB types have multiple speed standards. It is important to know that some USB cables are designed for data transfer only, while some can only deliver power. However, some USB cables can serve both purposes at the same time. Therefore, it is necessary to verify the performance of the cable before purchasing it.
USB Video Transfer
The ability of USB ports to power devices and transfer data between devices is already impressive enough. However, you can decide to integrate USB-C to connect a monitor in place of a VGA cable or HDMI. In addition, USB-C also supports 4K video transmission.

What are the advantages of USB interface?

Standard uniformity. The most common ones are hard disks with IDE interfaces, mouse and keyboards with serial ports, and printers and scanners with parallel ports. However, with USB, all these application peripherals can be connected to personal computers using the same standard. At this time, there are USB hard disks, USB mice, USB printers, etc.
Easy to carry. Most USB devices are known for being “small, light, and thin”, which is very convenient for users to carry large amounts of data with them.
Hot-swappable. That is, when users use external devices, they do not need to shut down and restart the computer, but directly plug in the USB when the computer is working.
Multiple devices can be connected. USB often has multiple interfaces on personal computers, and several devices can be connected at the same time. If a USB HUB with four ports is connected, four USB devices can be connected, and so on. You can connect all the devices to a personal computer at the same time without any problems (up to 127 devices can be connected).

How Do USB Ports Work?

USB is an external bus standard used to regulate the connection and communication between computers and external devices. The USB interface has plug-and-play and hot-swap functions. The USB interface can connect 127 peripherals, such as mice and keyboards. USB was jointly launched by Intel and other companies in 1994 and has successfully replaced serial and parallel ports since 1996. It has become a must-have interface for computers and a large number of smart devices today. For most engineers, the main obstacles to developing USB2.0 interface products are: facing the complex USB2.0 protocol, writing USB device drivers by themselves, and being familiar with microcontroller programming.

Why USB Ports Are Replacing Serial Ports

USB has three major advantages. It is superior to serial ports in several aspects.

Speed
USB ports are able to transfer data at a much faster speed. They work ten times faster than regular parallel ports. Also, they are much faster than serial ports. On average, serial ports offer a data transfer rate of 150kbps. On the other hand, USB ports offer about 12 Mbps. The data transfer rate depends on the type of USB port. For example, USB 2.0 has a maximum data transfer rate of 480 Mbps.

Compatibility
USB ports have replaced serial ports in the past few years. Various industrial devices are equipped with serial ports. This replacement has brought problems. USB ports are generally compatible with most USB devices.

Durability
USB ports are more durable than serial ports. The tiny pins on a serial port can break or bend easily. Whereas USB ports are very sturdy.

Frequently Asked Questions

The USB interface cannot be used. It may be due to a problem with the system. You need to check whether the system service is disabled or reinstall the operating system.

‌BIOS setting problem‌. If USB is disabled in BIOS or CMOS, you need to restore it to the factory default settings.

‌USB driver is not installed or the driver is deleted‌. You need to install the USB universal driver.

‌The front USB cable is not connected properly‌. Try to insert the USB flash drive into the USB interface on the back of the chassis.

‌The USB interface voltage is insufficient. When the mobile hard disk is connected to the front USB interface, it may not be recognized due to insufficient voltage. You should use a hard disk box with an external power supply or replace the power supply.

‌Compatibility issues between the motherboard and the system‌. For example, the compatibility issues between the NF2 motherboard and USB require the installation of the latest dedicated USB2.0 driver and patch.

‌System or BIOS problem‌. When USB is disabled in the BIOS or operating system, you need to enable options related to USB devices.

‌Be careful when plugging and unplugging. Do not unplug during reading and writing, otherwise the chip may be burned.

‌If the USB device is frequently disconnected‌, it may be that the USB cable connection is unstable or there is a problem with the USB port. Try changing the cable or connecting to another USB port.

‌If the USB device cannot be recognized or charged‌, make sure the device is compatible and the cable is intact. Try connecting to another computer or updating the driver.

What is BGA?

Ball grid array (BGA) is a common surface mount package that is derived from pin grid array (PGA) technology. It uses a grid of solder balls or leads to conduct electrical signals from the integrated circuit board. Instead of using pins like PGA, BGA uses solder balls placed on a printed circuit board (PCB). By using conductive printed wires, PCBs support and connect electronic components.

Unlike PGA, which has hundreds of pins and is difficult to solder, BGA solder balls can be evenly distributed without accidentally connecting them together. Solder balls are first placed in a grid pattern on the bottom of the package and then heated. By using surface tension when melting the solder balls, the package can be aligned with the circuit board. The solder balls cool and solidify, with accurate and consistent distances between each other.

What does a BGA do?

The main role of BGA (Ball Grid Array) packaging technology includes providing high-density, high-performance packaging solutions for microprocessors, ASICs, DSPs, PDAs, PLDs and other devices. This technology achieves surface mounting by making array solder balls on the bottom of the package substrate as the I/O end of the circuit to interconnect with the printed circuit board (PCB).

BGA packaging technology is small, light, and high-performance. It can provide more pins than other packaging technologies such as dual in-line package (DIP) or quad flat package (QFP). The entire bottom surface of the device can be used as pins instead of only the periphery.

This allows BGA packages to have shorter average wire lengths than periphery-limited package types, thereby providing better high-speed performance.

The advantages of BGA packaging are not only its high density and high performance, but also its less stringent requirements for welding accuracy. Even during the soldering reflow process, even if the solder ball is offset from the pad, the device position can be automatically corrected due to the surface tension of the solder.

What are the disadvantages of BGA?

The disadvantages of BGA packaging technology mainly include difficulty in detection, high difficulty in repair, relatively high production cost, stricter requirements on the reliability of solder joints, and sensitivity to temperature and humidity. ‌

1. Difficulty in detection: Since the solder ball is located at the bottom of the chip, the traditional optical inspection method cannot effectively detect the welding quality, and X-ray detection and other equipment must be used, which increases the cost and time of detection. ‌

2. High difficulty in repair: If there is a welding problem, the BGA packaged device needs to be disassembled and reassembled. This process has high technical requirements and certain risks. ‌

3. Relatively high production cost: Compared with QFP packaging, BGA packaging has higher material, production and inspection costs. ‌

4. More stringent requirements on the reliability of solder joints: Due to its small size, the BGA packaging method has very high requirements on solder joints. If there are problems such as empty solder joints and cold solder joints in the solder joints, the BGA package will fail.

5. Sensitive to temperature and humidity: BGA packaged components are very sensitive to temperature and humidity and need to be stored under constant temperature and dry conditions.

These shortcomings have limited the widespread application of BGA packaging technology to a certain extent, especially in application scenarios with high requirements for cost, reliability and environmental adaptability.

How is BGA made?

The production process of BGA (ball grid array package) mainly includes several key steps, which ensure the high quality and high reliability of BGA package. ‌

1. Wire bonding PBGA packaging process flow:

Substrate preparation: extremely thin copper foil is laminated on both sides of the BT resin/glass core board, and then drilling and through-hole metallization are performed.

‌Graphic production: Use conventional PCB processing technology to make graphics on both sides of the substrate.

‌Solder mask production: Add solder mask and make graphics to expose electrodes and welding areas to improve production efficiency. A substrate usually contains multiple PBGA substrates.

2. ‌BGA area via plugging‌:

The vias in the BGA pad area generally need to be plugged to prevent foreign matter in the hole or to protect the service life of the via, and to prevent the via from tinning during the reflow soldering of the SMT patch, causing a short circuit on the other side.

3. ‌Via in the plate, HDI design‌:

For BGA chips with small pin spacing, when the pin pad cannot be connected due to the process, it is recommended to directly design the via in the plate, and use the HDI blind buried hole wiring method to design the PCB, punch the via in the plate on the BGA pad, punch the buried hole in the inner layer, and conduct the wiring in the inner layer.

4. ‌BGA welding process‌:

‌Printing solder paste‌: Apply an appropriate amount of solder paste evenly on the PCB pad to ensure that the patch components and the corresponding pads on the PCB achieve good electrical connection and sufficient mechanical strength during reflow soldering.

‌Device placement‌: Use a placement machine to accurately mount the chip components to the corresponding position on the PCB surface printed with solder paste or patch glue.

5. Special size design and automated production:

BGA features include high pinhole density, easy automated production, high reliability, and the ability to design special sizes to achieve a more compact chip layout.

What is the difference between PCB and BGA?

The main differences between PCB and BGA are their structure, function, and application scenarios. ‌

1. Structure:

PCB (printed circuit board) is a basic electronic component that provides an electrical connection path between components. BGA (ball grid array package) is an advanced packaging method that connects components to PCB through a spherical pad array, with the advantages of high density and high reliability.

The pins of BGA are spherical and are generally directly soldered on the PCB board. Desoldering requires a special BGA rework station, and individuals cannot desolder; while the pins of PGA (pin grid array package) are pin-shaped. When installing, the PGA can be inserted into a special PGA socket for easy disassembly.

2. Functions and application scenarios:

BGA packaging effectively uses PCB space, which helps save enough space for customization in PCB and improve its efficacy. The size of BGA package is very small, so these PCBs have less heat dissipation and are easy to achieve the dissipation process.

There are no bendable or fragile pins in BGA package, so the durability of these PCBs is increased, and good electrical performance is also ensured. The pads of BGA package are large enough to make it easy to solder and easy to operate, so easy soldering and handling make it very fast to manufacture.

In summary, BGA, as an advanced packaging technology, has been widely used in high-performance electronic products through its unique ball grid array structure and high density and high reliability characteristics. Traditional PCBs provide basic electrical connection paths and are the basic components of electronic devices.

How many types of BGA are there?

There are many types of BGA, mainly including:

1. PBGA (plastic package BGA): This is the most commonly used BGA packaging form, made of plastic materials and plastic processes.

2. CBGA (ceramic BGA): This packaging type uses a multi-layer substrate with precious metal interconnect circuits.

3. CCGA (ceramic solder column array)

4. TBGA (BGA with tape)

5. MBGA (metal BGA)

6. FCBGA (flip chip BGA)

7. EBGA (BGA with heat sink)

In addition, BGA can be divided into staggered type, full array type, and peripheral type according to the arrangement of solder balls.

Conclusion:

Ball grid array (BGA) packaging is a key technology in modern electronic products. It makes it possible to develop more powerful and compact devices. BGA has become the first choice for applications that require high performance, reliability and miniaturization.

BGA packaging is famous for its advanced packaging technology. BEST Technology is recognized as the most trusted one-stop electronic circuit solution provider in the world, and BGA production is one of its most important projects. We specialize in the production and assembly of PCBs containing BGA packaging.

What is the composition of solder paste?

Solder paste is a complex mixture of multiple components, and its main components include metal powder, flux and solvent.

What is solder paste? What is its function?

The metal powder in solder paste is usually composed of metal alloys such as tin, silver and copper. The particle size and distribution of metal powder have a direct impact on the welding effect. The smaller the particle size, the more uniform the distribution, and the better the welding effect.

At the same time, the composition of the metal alloy also determines the mechanical strength and electrical properties of the solder joint.

Flux is another important component in solder paste. Its main function is to remove oxides on the welding surface and improve the wettability and reliability of welding.

The type and formula of flux directly affect the melting state and solder joint quality during the welding process. Common fluxes include rosin-based flux, organic acid flux and halogen-free flux.

Solvents are used to adjust the viscosity and printing performance of solder paste. Appropriate viscosity can ensure that the solder paste is evenly distributed during the printing process without problems such as drawing and collapse. The evaporation rate of the solvent will also affect the drying time and welding performance of the solder paste.

What is the role of solder paste in SMT patches?

In the SMT (surface mount technology) patch processing process, solder paste plays a vital role. It is not only used to bond components, but also the key to ensure the quality of electrical connections and mechanical strength.

1. Bonding components

One of the main functions of solder paste is to bond components. After the solder paste is accurately printed on the pads of the PCB (printed circuit board), the pins or contact points of the electronic components will be placed on the solder paste. The solder paste melts during the reflow soldering process to form a strong bond, ensuring that the components are stably attached to the PCB.

2. Provide electrical connection

Solder paste melts during the reflow soldering process and forms metal solder joints, which not only bond components but also provide electrical connections. Good electrical connections ensure the effective transmission of electrical signals on the PCB, which is the basis for ensuring the normal operation of electronic equipment.

The solder joints formed by the metal components (such as tin, silver, and copper) in the solder paste after melting have excellent conductivity, ensuring the reliability and stability of electrical connections.

3. Ensure mechanical strength

The mechanical strength of the solder joints is the key to ensuring the stable operation of electronic components in various environments. The solder joints formed by the solder paste after reflow soldering have sufficient mechanical strength to resist external stresses such as vibration, impact, and thermal expansion and contraction. This not only protects the components and PCB, but also improves the reliability and service life of the entire electronic equipment.

Is solder paste the same as flux?

Solder paste and flux are not the same. ‌

Although both solder paste and flux are materials used in the welding process, their functions and uses are different.

Solder paste is a paste-like viscous body, the main components of which include metal powder, rosin, organic acid, thixotropic agent, and activator, and is used for welding in SMT automatic mounting process.

Flux is a liquid, a mixture with rosin as the main component, which is used to remove oxides on the surface of solder and the base material to be welded, so that the metal surface reaches the necessary cleanliness, prevents the surface from re-oxidation during welding, reduces the surface tension of the solder, and improves welding performance.

In general, although both solder paste and flux are indispensable materials in the welding process, they have obvious differences in form, function, and usage.‌

What is the storage method of solder paste?

The correct storage method can extend the service life of the solder paste and ensure its stable performance.

1. Temperature control

Solder paste should be stored in a low temperature environment, usually 0-10℃. Excessive temperature will cause the solvent in the solder paste to volatilize, affecting its viscosity and printing performance. Avoid direct sunlight and high temperature environment during storage to prevent the solder paste from deteriorating.

2. Humidity control

Humidity has a great impact on solder paste. Excessive humidity will cause the solder paste to absorb moisture, affecting its printing performance and welding quality. The relative humidity of the storage environment should be controlled below 50% to ensure the stability of the solder paste.

3. Sealed storage

The solder paste should be stored in a sealed container to prevent oxygen and moisture from entering the air. The solder paste after opening should be used up as soon as possible, and the unused solder paste should be resealed and stored in a low temperature environment.

How to use solder paste correctly?

1. Reheating treatment

The solder paste stored in a low temperature environment should be reheated before use. The reheating time is usually 4-8 hours. During the reheating process, it should be avoided to be directly exposed to a high temperature environment to prevent the solvent in the solder paste from volatilizing. The solder paste after reheating should be fully stirred to ensure that the metal powder and flux are evenly distributed.

2. Printing process

Solder paste printing is a key process in SMT patch processing. During the printing process, the scraper pressure, printing speed and template opening size should be controlled to ensure that the solder paste is evenly distributed on the pad. The printed solder paste should have a good shape and should not have problems such as drawing and collapse.

3. Solder paste reflow

The solder paste reflow process is the process of melting the solder paste and forming a firm solder joint with the pad and component pin. The temperature curve should be controlled during the reflow soldering process to ensure that the solder paste melts at an appropriate temperature and fully wets the pad and pin. Too high or too low reflow temperature will affect the welding quality.

4. Solder joint detection

The quality of the solder joint is an important indicator for evaluating the welding effect. After the welding is completed, the solder joint detection should be carried out to check the shape, size and wettability of the solder joint. Qualified solder joints should have a smooth and complete surface without defects such as solder balls and cold solder joints.

Conclusion:

Solder paste plays a vital role in SMT patch processing. Its composition, selection, storage and use methods directly affect the welding quality and the performance of the final product. By understanding and mastering the relevant knowledge of solder paste, the quality of SMT patch processing can be effectively improved, and defects and rework rates can be reduced.

BEST Technology has rich experience and strict control standards in the selection and use of solder paste, and can provide customers with high-quality SMT patch processing services. If you have any questions about our products or services, please feel free to contact us. Choose BEST Technology , choose quality assurance.

What is flux?

Flux: A chemical substance that can help and promote the soldering process in the soldering process, and at the same time has a protective effect and prevents oxidation reactions. Flux can be divided into solid, liquid and gas.

There are mainly several aspects such as “assisting heat conduction”, “removing oxides”, “reducing the surface tension of the material to be soldered”, “removing oil stains on the surface of the material to be soldered, increasing the soldering area”, and “preventing re-oxidation”. Among these aspects, the two most critical functions are: “removing oxides” and “reducing the surface tension of the material to be soldered”.

Do you apply flux before or after soldering?

Use flux before soldering printed circuit boards. ‌

During the soldering process of printed circuit boards, the main purpose of using flux is to improve soldering performance and help the metal avoid the formation of an oxide film that hinders solder wetting when heated, thereby promoting the formation of solder-metal alloys and avoiding the occurrence of cold soldering and false soldering.

Flux can be applied to the printed circuit board before soldering, or it can be used as part of the solder during the soldering process, such as solder paste or solder oil. When tinning the pins of components, rosin should be used as the flux, and if the printed circuit board is already coated with rosin solution, then no additional flux is required during soldering.

After using flux, make sure to wipe off the residual flux at the soldering site after soldering to avoid potential damage to electronic components and circuit boards.

In addition, the preparation work before soldering includes thoroughly cleaning the copper foil surface and then applying rosin water to protect the copper foil and help soldering. This step is performed before soldering to ensure the smooth progress of the soldering process. Therefore, the correct approach is to use flux before soldering printed circuit boards to ensure the quality and reliability of soldering.

How much flux to use when soldering?

When soldering printed circuit boards, the amount of flux used needs to be determined according to the specific soldering method and the type of flux. For wave soldering flux, when using brushing and foaming methods, the specific gravity of the flux should be controlled between 0.82-0.84 (specific gravity of liquid rosin flux stock solution).

During the soldering process, the specific gravity of the flux needs to be measured regularly. If the specific gravity is found to increase, it should be adjusted to the normal range with diluent in time, but the diluent should not be added too much to avoid affecting the soldering quality.

For the quantitative spraying method, the key is that the nozzle can control the spray volume. The nozzle should be cleaned frequently to ensure that the spray hole is not blocked. The spray pressure should be controlled at 0.2-0.3Mpa, the flux pressure should be controlled at 0.4±0.05Mpa, and the spray flow rate should be controlled at 20-35ml/min.

In addition, different types of flux formulas are also different. For example, rosin liquid can be made by mixing rosin blocks and alcohol in a ratio of 1:3. For the flux of printed circuit boards, you can directly use rosin water, and apply the prepared rosin water directly on the surface of the printed circuit board or the solder joints.

When using flux, you should also pay attention to the following points:

Put the bottle cap on immediately after use to prevent the flux from being in contact with air for a long time and causing oxidation reaction or absorbing water vapor in the air to cause the concentration to decrease.

Regularly replace the flux that has been stored for too long, because long-term storage will cause the flux composition to change and the activation performance to deteriorate, affecting the welding quality.

Clean it after welding, because the insulation performance of the flux will drop sharply at high temperature, and the residue may affect the heating components, and in severe cases may cause short circuits.

In summary, the amount of flux used in printed circuit board welding needs to be determined according to the specific welding method and flux type, and pay attention to the use and storage conditions of the flux to ensure welding quality and safety.

What happens if you use too much flux when soldering?

First, the main functions of flux include assisting heat conduction, removing oxides, reducing the surface tension of the material being soldered, removing oil stains on the surface of the material being soldered, increasing the soldering area, and preventing reoxidation.

However, excessive use of flux can lead to corrosion and electromigration. This is because improper use of flux, such as excessive use, can create more favorable conditions for potential chemical corrosion reactions.

In addition, if the flux used is not well controlled, resulting in excessive use of flux, more flux residue will be left, which creates more favorable conditions for potential chemical corrosion reactions.

Therefore, it is very important to control the amount of flux used to avoid negative effects on soldering quality and reliability.

What happens if I don’t use flux?

If flux is not used on printed circuit boards, it may lead to reduced soldering quality, increased soldering difficulty, and affect the performance and reliability of the circuit.

1. Increased soldering difficulty: Without flux, the solder may be difficult to flow to the soldering point, resulting in loose soldering, prone to cold soldering or poor soldering.

2. Reduce welding quality: Without the help of flux, the soldering point may not be smooth enough, with burrs or unevenness, which may affect the normal operation of the circuit.

3. Affect circuit performance and reliability: Flux can reduce the resistance of the soldering point and improve the conductivity of the circuit. Without flux, the resistance of the soldering point may increase, affecting the performance and stability of the circuit.

In addition, the flux can also prevent oxidation to a certain extent, protect the soldering point from the influence of the external environment, thereby improving the life of the circuit. Therefore, in the soldering process of printed circuit boards, it is very important to use the soldering flux correctly.

What is an alternative to soldering flux?

Alternatives to printed circuit board soldering flux include no-clean soldering flux, special solder resist for printed circuit boards, water-based cleaning agents and dry ice cleaning technology. ‌

1. No-clean soldering flux is a new type of soldering flux that does not contain halide activators. It does not need to be cleaned after use, which can save investment in cleaning equipment and cleaning solvents, while reducing the emission of waste gas and wastewater, and the pollution to the environment is also reduced accordingly.

2. The main function of the ‌PCB solder mask‌ is to prevent “wiring” and short circuits during wave soldering and protect the PCB permanently. In addition, it can save solder, reduce the weight of the PCB, and reduce costs.

3. As a new type of cleaning medium, the ‌water-based cleaning agent‌ achieves cleaning through the wetting, dissolution, emulsification, saponification, chelation and other effects of the surfactants, emulsifiers, penetrants, etc.

4. The ‌dry ice cleaning technology‌ uses extremely low-temperature dry ice particles to spray onto the treated object under the action of compressed air, so that the dirt is rapidly frozen to brittleness and burst, and then vaporized to take away the dirt.

These substitutes have their own characteristics and are suitable for different application scenarios and technical requirements. When choosing, specific process requirements and cost-effectiveness must be considered.

What does rosin do when soldering?

In the process of printed circuit board soldering, rosin plays a vital role. It is mainly used as a flux to help the soldering process be smoother and more efficient. The role of rosin is reflected in the following aspects:

‌Removing oxide film‌: Rosin can remove the oxide film formed on the copper surface due to contact with air. These oxide films will prevent the tin from wetting the copper wire, thus affecting the quality of welding.

‌Preventing re-oxidation‌: Rosin can not only remove the oxide film, but also prevent the soldering surface from re-oxidizing during the welding process, which helps to maintain the stability and reliability of the welding point.

‌Isolating air‌: Under high temperature conditions of welding, rosin can isolate the air and prevent oxidation of the metal surface.

In summary, rosin plays an important role in the soldering process of printed circuit boards. Through its fluxing effect, it improves the quality and reliability of soldering and is one of the indispensable materials in electronic manufacturing‌.

Conclusion:

Flux is a key part of the soldering process. Without it, your solder will not flow smoothly through the joint and the solder will not adhere properly to the various components on the circuit board. High-quality flux is necessary to produce good solder joints.

BEST Technology is a professional PCB circuit board manufacturer with many years of experience in PCB circuit board welding. The circuit boards it produces are of extremely high quality. We have the most extensive experience to deal with all aspects of PCB welding issues.

What is the surface mount technology process?

The process of surface mount technology (SMT) mainly includes the following steps:

1. Printed circuit board preparation: Before surface mounting, the printed circuit board needs to be prepared first, including cleaning the circuit board, removing the surface oxide layer, and applying solder paste.

2. Component mounting: Use appropriate equipment to accurately mount various electronic components on the printed circuit board.

3. Soldering: After the components are mounted, the solder paste is heated to melt it to form a reliable welding connection.

4. Inspection: After welding, use AOI for automatic inspection to ensure the correct mounting and welding quality of components.

5. Testing and debugging: Test and debug the mounted circuit board, and verify whether the function and performance of the circuit board meet the requirements through specific test equipment and procedures.

Each step needs to be carried out carefully to ensure that the mounted circuit board has good quality and reliability. In addition, surface mount technology is suitable for circuit board assembly, with the characteristics of compact structure and small size, and is widely used in the manufacture of electronic products.

What are the roles of surface mount?

The role of surface mount technology (SMT) is mainly reflected in improving the performance, reliability and production efficiency of electronic products, while reducing the volume and weight of products.

Surface mount technology (SMT) has the following significant effects:

Increase assembly density and reduce product volume: By using surface mount technology, the volume of electronic products can be reduced by 40%~60% and the weight can be reduced by 60%~80%.

‌Improve reliability: SMT has high reliability, low solder joint defect rate and strong vibration resistance.

Optimize high-frequency characteristics: SMT reduces electromagnetic and radio frequency interference and optimizes the high-frequency characteristics of the circuit.

Automated production: SMT is easy to automate, thereby improving production efficiency.

Enhanced compactness: Using small surface-mounted components can save a lot of space on the printed circuit board, and circuit assembly is easier to automate.

Adapt to a wide range of fields: As a new generation of electronic assembly technology, SMT has penetrated into various fields, including but not limited to computers, communication equipment, consumer electronics, etc.

In summary, surface mounting technology has significantly improved the comprehensive performance and production efficiency of modern electronic products by increasing assembly density, optimizing circuit performance, enhancing product reliability, and realizing automated production.

What is the advantage of surface mount?

The advantages of surface mounting mainly include:

High assembly density: Surface mounting technology (SMT) allows more electronic components to be installed in a limited space.

Small size and light weight of electronic products: By using SMT, smaller and lighter electronic products can be manufactured.

‌High reliability‌: SMT has a low solder joint defect rate, which improves the reliability of the product‌.

‌Easy to automate‌: SMT technology is very suitable for automated production and can greatly improve production efficiency‌.

‌Design flexibility‌: SMT allows different components to be used on the same circuit board, providing design flexibility‌.

‌EMC compliance‌: SMT technology helps meet electromagnetic compatibility (EMC) requirements and ensure the safety and performance of the equipment‌.

‌Selective soldering‌: SMT supports selective soldering, which increases the customizability of the product‌.

In addition, SMT technology is cost-effective because the packaging size of components is generally standardized and can be quickly and accurately installed using automated equipment, thereby reducing production costs‌. At the same time, SMT reduces human errors and improves product quality because the placement of components is very consistent, reducing errors or the need for rework.

What are the disadvantages of surface mount?

‌The disadvantages of surface mount technology (SMT) mainly include incompatibility with certain components, the possibility of soldering defects, and high equipment costs. ‌

‌Incompatibility with certain components‌: SMT technology is not suitable for all types of components.

‌Possibility of soldering defects‌: Although SMT technology reduces the need for drilling and shortens setup time, it is not a zero-defect soldering process. In actual applications, SMT may encounter various soldering defects.

‌Higher equipment cost‌: Although SMT technology can improve production efficiency and circuit density, it requires expensive special equipment and professional technicians.

In summary, although SMT technology has many advantages, such as reducing drilling, shortening setup time, and improving production efficiency, it also has some disadvantages, especially in terms of incompatibility with certain components, possible soldering defects, and high equipment costs.

What does SMD stand for in surface mount?

SMD stands for Surface Mounted Devices. ‌

SMD is a type of component in surface mount technology (SMT), which is characterized by small size, high power, stable performance, and easy automated assembly.

SMD packaging technology can maximize the space utilization on the circuit board, especially for the design of dense circuit boards. SMD packaging usually adopts metal oxide semiconductor (MOS) technology, and its packaging methods are diverse, including COB, QFN, LCC, BGA, etc.

In practical applications, the appearance inspection of SMD devices includes visual inspection or use of a magnifying glass to check whether the solder end or pin surface is oxidized or has contaminants, and to ensure that the nominal value, specification, model, accuracy, and external dimensions of the components are consistent with the product process requirements. To ensure the performance and reliability of the device.

The wide application of SMD technology not only improves the performance of electronic products, but also promotes the automation and efficiency improvement of the electronics manufacturing industry. It is an indispensable part of the modern electronics manufacturing industry, especially in applications that require high integration and high reliability.

What is the application of surface mount?

The application of surface mount technology is mainly reflected in improving production efficiency, reducing product volume and weight, and meeting the market demand for miniaturized, lightweight, and high-performance electronic products. This technology is mainly used to mount electronic components on printed circuit boards (PCBs) to achieve circuit connection and system integration.

Surface mount technology can replace traditional through-hole insertion technology, thereby improving product reliability and performance and reducing costs. The technology has a wide range of applications, including but not limited to consumer electronics, military cutting-edge electronics, and fire detectors, manual alarms, and various electronic modules.

In the manufacture of electronic products, surface mount technology has become a revolutionary change, dominating the development of electronic equipment and bringing about major changes in electronic products.

Conclusion:

Usually, the electronic products we use are designed by PCB plus various capacitors, resistors and other electronic components according to the designed circuit diagram, so most electrical appliances require various SMT (patch) processing technologies to process.

BEST Technology focuses on the procurement and processing of various electronic products and processing services for incoming materials, including but not limited to SMT patches, DIP plug-ins, welding, functional testing and maintenance, and assembly proofing and batch production. We can provide proofing, small batch and batch SMT mounting, and can also purchase electronic components and make PCBs.

Archive for the ‘SMT Technology’ Category

What Is the Clearance Rule for PCB?

How Close Can Components Be on a PCB?

What Is the Spacing Between SMD Pads?

What Is the Difference Between SMT and SMD Components?

How Close Can PCB Traces Be?

What Is the Edge Clearance of a PCB?

Additional Considerations for SMT Clearance and Spacing

Practical Tips for Ensuring Proper Clearance Between PCBs

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Is silver oxidation permanent?

What is the best way to Deoxidize silver?

How do you save silver from oxidation?

What is the shelf life of immersion silver PCB?

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What is Soldering?

What is Soldering Primarily Used For?

What Temperature Does Solder Melt?

Does Solder Have Lead?

What is the Melting Point of Solder?

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Is Tenshan Lead-Free?

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What does PCBA mean?

Applications of PCBA

Common components on a PCBA and their symbols

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What Does POP Do in Assembly?

SMT POP Structure

Amkor PoP Typical Structure:

Bottom PSvfBGA Structure:

Top SCSP Structure:

SMT POP Manufacturing Process

POP Design Considerations

What are the advantages of POP smt process?

POP Applications

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Usb connector types

What functions does USB have?

What are the advantages of USB interface?

How Do USB Ports Work?

Why USB Ports Are Replacing Serial Ports

Frequently Asked Questions

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What is BGA?

What does a BGA do?

What are the disadvantages of BGA?

How is BGA made?

What is the difference between PCB and BGA?

How many types of BGA are there?

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What is the composition of solder paste?

What is the role of solder paste in SMT patches?

Is solder paste the same as flux?

What is the storage method of solder paste?

How to use solder paste correctly?

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What is flux?

Do you apply flux before or after soldering?

How much flux to use when soldering?

What happens if you use too much flux when soldering?

What happens if I don’t use flux?

What is an alternative to soldering flux?

What does rosin do when soldering?

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What is the surface mount technology process?

What are the roles of surface mount?

What is the advantage of surface mount?

What are the disadvantages of surface mount?

What does SMD stand for in surface mount?

What is the application of surface mount?

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