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Archive for the ‘PCBA’ Category

What You Know About Counterbores in PCB Design and Manufacturing

Friday, August 18th, 2023

In the world of design and manufacturing, precision is paramount. Every detail, down to the placement of a single component, can impact the performance and appearance of a product. This is where the concept of counterbores comes into play, a technique employed in various industries to create recessed areas for components or fasteners.

But firstly, what is counterbore? Today we will show you the definition and applications of the countersink in a PCB design.

Definition and Applications:

A counterbore is a cylindrical, flat-bottomed hole that is strategically cut into a material to accommodate specific components or fasteners. It is commonly used in various industries, including woodworking, metalworking, and mechanical engineering. The purpose of a counterbore is to create a recessed area where a component, such as a bolt head, nut, or other hardware, can sit flush with or below the surface of the material. This technique ensures a smooth appearance, prevents interference with other components, and provides mechanical stability.

Counterbores in PCB Design and Manufacturing

In the realm of printed circuit boards (PCBs), counterbores play a crucial role in achieving efficient and functional designs. PCBs are essential components in electronic devices, and their design requires careful consideration of component placement, connectivity, and mechanical stability. Counterbores in PCBs serve several important functions:

Component Alignment and Clearance: Certain components on a PCB, such as connectors, switches, or specialized modules, require precise alignment and clearance for optimal functionality. A counterbore can be introduced to create a recessed area that accommodates these components, ensuring proper alignment with neighboring components and minimizing the risk of interference.

Flush Mounting: To maintain a sleek and compact design, some components need to be mounted flush with the surface of the PCB. A counterbore creates a flat-bottomed recess that allows the component to sit at the same level as the PCB surface, contributing to an aesthetically pleasing and functional layout.

Mechanical Support: Components that are susceptible to mechanical stress or impact may benefit from additional support. By incorporating a counterbore, the PCB design can provide a more secure location for these components, reducing the risk of damage.

Heat Dissipation Enhancement: In applications where certain components generate significant heat, such as power amplifiers or processors, heat sinks are often employed to dissipate the heat. A counterbore can facilitate proper alignment and contact between the heat sink and the component, optimizing heat transfer and overall thermal performance.

The production of counterbores in PCBs involves specialized manufacturing techniques. BEST Technology as a professional PCB manufacturer, we will use precision drilling and routing equipment to create accurately sized and positioned counterbores.

If you want to know more about the counterbores, welcome to follow our post or contact us.

5 Tips Tell You How to Solder BGA Better in PCBA

Monday, May 29th, 2023

BGA (Ball Grid Array) soldering is a widely used method in the electronics manufacturing industry for mounting integrated circuits onto printed circuit boards (PCBs). This method provides a more compact and reliable connection compared to traditional through-hole or surface mount technology (SMT). However, the complexity of BGA soldering poses various obstacles during the manufacturing process. Herein, we will explore the challenges faced in BGA soldering and discuss effective strategies to address them.

What is BGA Soldering?

BGA soldering is a technique that involves the attachment of integrated circuit packages to a PCB using an array of solder balls. These solder balls are typically made of lead-based or lead-free alloys, depending on environmental regulations and specific requirements. The BGA package consists of a substrate, which acts as a carrier for the integrated circuit, and the solder balls that form the electrical and mechanical connections between the package and the PCB.

The Importance of BGA Soldering in Electronics Manufacturing

BGA soldering plays a critical role in the manufacturing of various electronic devices such as computers, smartphones, and gaming consoles. The increased demand for smaller and more powerful electronics has driven the adoption of BGA packages. Their compact size and high pin density make them suitable for advanced applications where space is limited.

Challenges Faced in BGA Soldering

Component Alignment and Placement

One of the primary challenges in BGA soldering is ensuring accurate component alignment and placement on the PCB. The small size of the solder balls and the dense layout of the BGA package make it difficult to achieve precise positioning. Misalignment during the assembly process can result in solder bridges, open connections, or mechanical stress on the package.

To address this challenge, manufacturers employ advanced technologies such as Automated Optical Inspection (AOI) and X-ray Inspection. AOI systems use cameras and image processing algorithms to verify the correct alignment and placement of BGA components. X-ray inspection, on the other hand, allows manufacturers to see beneath the surface of the PCB and detect any misalignment or defects that may not be visible to the naked eye.

Solder Paste Application

Another significant challenge in BGA soldering is achieving precise and consistent solder paste application. Solder paste, a mixture of solder alloy and flux, is applied to the PCB pads before placing the BGA package. Inadequate or excessive solder paste can lead to solder defects such as insufficient solder joints, solder voids, or solder bridging.

To overcome this challenge, careful attention must be given to stencil design and aperture selection. Stencils with appropriate thickness and properly sized apertures ensure accurate solder paste deposition. Additionally, manufacturers can employ Solder Paste Inspection (SPI) systems to verify the quality and consistency of the solder paste applied. The solder paste that Best Technology uses is SAC305 solder paste, which has good printability and excellent stability.

Temperature Profiling

Temperature profiling, or we can say the thermal management, it is crucial in BGA soldering to ensure proper reflow of the solder paste. The reflow process involves subjecting the PCB to a carefully controlled temperature profile, allowing the solder paste to melt, form a reliable joint, and solidify. Inadequate temperature profiling can lead to insufficient solder wetting, incomplete reflow, or thermal damage to components.

Manufacturers must optimize the reflow oven setup and calibration to achieve the correct temperature profile. Thermal profiling techniques, such as the use of thermocouples and data loggers, help monitor and control the temperature during the reflow process.

Reflow Process

The reflow process itself presents challenges in BGA soldering. The soak zone, ramp rates, and peak temperature must be carefully controlled to prevent thermal stress on the components and ensure proper solder reflow. Inadequate temperature control or improper ramp rates can result in solder defects such as tombstoning, component warpage, or voids in the solder joints.

Manufacturers need to consider the specific requirements of the BGA package and follow recommended reflow profiles provided by component suppliers. Proper cooling after reflow is also essential to prevent thermal shock and ensure the stability of the solder joints.

Inspection and Quality Control

Inspection and quality control are critical aspects of BGA soldering to ensure the reliability and performance of the solder joints. Automated Optical Inspection (AOI) systems and X-ray inspection are commonly used to detect defects such as misalignment, insufficient solder wetting, solder bridging, or voids in the solder joints.

In addition to visual inspection techniques, some manufacturers may perform cross-section analysis, where a sample solder joint is cut and examined under a microscope. This analysis provides valuable information about the quality of the solder joint, such as solder wetting, void formation, or the presence of intermetallic compounds.

In a word, BGA soldering presents unique challenges in electronics manufacturing, primarily related to various factors. By addressing these challenges effectively, manufacturers can ensure the reliability and performance of BGA solder joints, contributing to the production of high-quality electronic devices. Best Technology has rich experience in PCBA assembly and we mounted thousands PCBs for our customers, whatever it is simple design or complex design, all the products are assemble perfect and work well in customer side. Please feel free to contact us for any questions about PCBA.

5 PCB Testing details to make your PCB no more quality issues

Monday, April 24th, 2023

As we all know, it is very important to get a well-functional PCB from the PCB manufacturers. A well functional PCB means that the electricity testing has been performed well at the PCB manufacturer end. However, you may have found some PCB you purchased are with some electricity issues like short & open circuits, or some visual issues like solder pad missing., etc.

Do you know how this issue come while the PCB testing process?

According to the feedback come from the customers, here we summarized some improper ways during the PCB Electricity testing process which may lead to the PCB fail to the test.

Here are some major points for your reference:

Incorrect direction when placing PCB board on testing worktop, the force on probes will cause indentation on boards.

PCB manufacturers don’t regularly maintain their testing jig, causing some malfunctions on testing jig can’t be found in time. Take the counter for example, if we do not find the counter’s fixing screw loose in time, it will cause the counter to fail to read the caliper scale. Of course, it also could be the counter is dysfunctional sometimes.

PCB manufacturers don’t regularly check/change the testing probes. Dirt on the testing probe cause testing results is inaccurate.

PCB testing operator don’t distinguish functional board from NG board due to unclear placement area.

So, if the circuit boards testing work under above improper way, do you know what effects will be on your products?

Base on some lessons learned from our customers, you may get following influences caused by improper way of the PCB testing.

Increase your quality issues

The low testing accuracy will make the functional PCB mixing together with the defective PCB. If the PCB testing defects can’t be found in time before PCB assembly, defective products will flow into the market, which will seriously increase the quality risk hidden on the end products.

Delay your Progress

After defective PCBs are found, repairing will greatly delay the progress of the project.

Increase your overall cost

The defective PCB will cost many people and time to check and follow, this will directly to increase the overall cost of the projects.

We know deeply that poor testing will bring serious consequences for customers, so with more than 16 years experiences on Printed Circuits Board fabrication, Best Technology has rich experiences on PCB electric testing managements, and following are some of our management solutions to control our PCB testing process:

1. We execute strictly the pre-job training 3 months in advance for the testing operator, and all the testing will be operated by the professional and experienced testers.

2. Maintain or replace the test equipment every 3 months, and use a brush to clean the tester in a regular period or replace the pin cable head to make sure there is no contaminate at the test probe.

3. Add the extra tooling hole at rails for fix purpose to make sure the placement of PCB orientation is no mistake during testing process.

4. The testing workshop must be divided clearly for the qualified board and NG board, the location to keep NG board will be marked with red line.

5. The testing process must be strictly followed with our internal PCB testing standard operating procedure.

With the help from above management solutions for the PCB E-Testing during the PCB manufacturing process, the PCB we send to customers works very well, which also make sure their products can be assembled well and deliver well in the markets. For us, more and more kindly feedback regarding the functional feedback comes from our customers, here are some good feedback from customers for your reference.

If you have any questions about PCB testing or PCB manufacturing, please feel your freely to leave your message or contact us. In our next update, we will share which test methods are used in the during the PCB Assembly.

Differences Between Solder Mask and Solder Paste in PCB

Wednesday, December 7th, 2022

When it comes to solder mask and solder paste, there are some engineers confused about their functionalities and even most of laymen thought they are the same, this is not hypothetical, it is real that happened to me. So today let’s explain differences between Solder Mask and Solder Paste for you.

Part 1: What is Solder Mask?

If you had ever seen a printed circuit board, you may see there is a layer of green ink cover on the PCB surface while some orange-yellow areas didn’t cover by ink. In PCB industry, the green ink we called Solder Mask, or abbreviated as S/M, and exposed area is copper, they were leave as GND plane or soldering pads to mount electronic components.

Solder mask is a liquid acrylic oligomer, which has variety of colors such as red, blue, green, white, black. Green is commonly used in the process of PCB manufacturing, so some professional engineers call it as green oil.

Solder mask applied on the PCB designed as a protection layer to avoid oxidation, corrosion and other environmental impacts when they leave production line. In addition, solder mask between solder pads also can help to prevent forming to solder bridge when assembly.

Below are some other functions of coating a layer solder mask:

Prevent physical line breaking of copper trace
Only weld in the area that must be soldered to avoid waste of soldering
Reduce copper pollution to soldering groove
Prevent insulation deterioration and corrosion caused by dust, moisture and other external environmental factors
With high insulation, so that the high-density circuit is possible

Part 2: What is Solder Paste?

Solder Paste also known as “Solder cream”, is a most important soldering material used in surface mount technology (SMT) process. Mainly function for soldering resistors, capacitors, ICs and other electronic components onto the PCB surface to form a permanent connection.

The solder particles are a mixture of solder formed by mixing solder powder, flux and other surfactants and thixotropic. Traditionally this used to be tin and lead, but with the legislation has been introduced around the world, to only use lead free solders. These may be made from a variety of mixtures, Best Technology commonly used is SAC305 which includes 96.5% tin, 0.5% copper and 3.0% silver, some manufacturers also use 99.7% tin and 0.3% copper, whereas there are other mixtures that include other metals including tin.

Due to the role of solder paste in assembly, solder paste storage is extremely important. However, solder paste got into drying during storing became a common problem faced by most PCBA manufacturers, so How to solve solder paste dry problem is premier.

Part 3: The Difference Between Solder Mask and Solder Paste

Solder mask is a formal part of PCB, but solder paste ONLY for PCB assembly.
Solder mask is not allowed on the solder pads while solder paste can be printed on the solder pads openings.
Solder mask is used for applying solder mask ink, but solder paste is used for applying paste.
Solder mask has many available colors, but paste mask visually gray.
Solder mask is coating during PCB fabrication, but solder paste is printing when PCB assembly.

With over 16 years in PCB industry, Best Technology is one of the most reliable PCB and PCBA supplier in Asia, we commit to provide high quality products with excellent service before and after sales, to take care our customers wholeheartedly, and to treat customers’ business as ours. At the same time, we keep learning and continually to improve ourselves so that we can catch up the latest technology trend and provide better and better service for our customers.

How To Do Failure Analysis In Printed Circuit Board

Saturday, October 29th, 2022

Nowadays, printed circuit board plays a more and more important role in electronic products, whether for personal use or commercial use, failure PCB can effect the usage of electronic products and cause a serious consequence. So, how to quickly detect the PCB fault problem?

Here, Best Tech summarized seven methods to locate fault PCB quickly.

Use testing equipment

The typical equipment including Automated Optical Inspection (AOI) equipment, X-Ray Fluoroscopy, Optical Microscopy, 1000x magnifying glass. When some failures happen and we don’t know what is the specific position, properly use of these detection devices can help us quickly locate the faulty PCB.

Visual inspection

Visual inspection is the most common and easy method to position those defectives in printed circuit board. It can identify defects such as overlapped marks, solder joint short, signs of overheating circuit boards, and burned components. When some problems are difficult to identify with our naked eye, magnifying glasses can help to identify some short circuits, welding bridges, open circuits, solder joints and circuit board wiring cracks, component offset, etc.

Components inspection

If the printed circuit board was assembled with some electronic components, we can perform a components inspection to locate the failure. Especially when low resistance is detected between the component pins, it is best to remove the component from the PCB circuit for specialized testing. If the resistance is still low, then this component is the culprit, otherwise further investigation will be required.

Power on printed circuit board

Visual inspection is only suitable for checking the appearance of outer layers of the circuit board, instead of for checking the inner layer of the circuit board. If there are no visible defects in the appearance, you can power up/on the board and perform a more detailed test to determine whether the board is working properly or not.

Low voltage measurement

The first thing to confirm is whether the voltage of each chip power pin is normal, and then check whether the various reference voltages are normal, and whether the working voltage of each point is normal. Since the copper trace on the circuit board has resistance, the voltage generated through different parts of the copper trace is also different. Then you can use a voltmeter or multimeter to measure the voltage between different parts along a short. If you find that the voltage value is getting smaller and smaller, you are getting closer to find out a short circuit.

For a simple example, when a typical silicon triode is on, the BE junction voltage is around 0.7V, while the CE junction voltage is around 0.3V or less. If the BE junction voltage of a triode is greater than 0.7V (except for special triode, such as the Darlington tube), the BE junction may be open.

Touch circuit board with your finger

In general, when some failure happened, some areas on the circuit board will be getting more and more heat. In this time, we can try to touch the circuit board with fingers to find out areas with heat, and it will help us to pinpoint the problem. However, be careful to use short-circuit copper trace power supply and avoid burns or electric shock.

Repair short/open

After identifying a short or open circuit on the PCB, the next step is to isolate the problem. While this is easy to do on the outer surface of the board, it is a challenge for the inner layers. Possible solutions include drilling through holes or cutting appropriate external copper traces.

This is the end of this article, if you have more better methods to locate the failure printed circuit board, warm welcome to contact us, we can analyze together.

Why Solder Paste became Dry and How to Solve This Problem

Thursday, August 18th, 2022

As a One-stop PCBA manufacturer, I believe most of manufacturers have faced a problem of solder paste became dry during SMT process, especially in hot summer, and there will be a large number of defects come out when solder paste was dry, such as poor printing, false solder, components be shifted, cold solder and so on, which will greatly decrease assembly efficiency and PCBA quality.

Do you know why the solder paste became dry?

After checking and discussing with our SMT engineers, we found the root cause of solder paste be dry is corrosion, in below images you can see the detailed solder powder morphology of corrosion.

2-a Solder powder from good solder paste

2-b Solder powder from dried solder paste

In generally, the main reason of corrosion is thermodynamic instability of metal, that is metal and its alloy is in a high free energy status than other chemical compound (for example, oxide, hydroxide, salt or others), when this situation occurs, metal will transform to lower energy, which is called corrosion.

Metal corrosion is under the basis of the theory of electrochemical, and it’s required four main elements: anode, cathode, electrolyte and constitute current path.

Now let’s parse the mainly metals in solder paste — Sn, Ag, Cu (or other impurities), then under the action of flux medium, numerous galvanic cells with Sn as the cathode and Ag/Cu as the anode are formed, then below chemical reaction will be happened:

Cathode: Sn – 2e → Sn²⁺

Anode: O₂ + H₂O + 4e → 4OH^–

That is: Sn + H₂O + ½O₂ → Sn(OH)₂

Sn(OH)₂decompose: Sn(OH)₂→ SnO + H₂O

Then chemical reaction of corrosion of solder powder under the moisture in the air can be described as:

The following figure shows the infrared spectrum of succinic acid liquor before and after soaking the solder powder. It can be clearly seen that the soaked liquor contains carboxyl. Therefore, in the solder paste system, except the oxidation reaction of electrochemical corrosion, salinization chemical reaction will be happened too:

Infrared spectrum of Chemical reaction between succinic acid solution and solder powder succinic acid liquor

So now, do you know why solder paste will be dry? And why it is more seriously in hot summer with high temperature and humidity?

Yes, its root cause is not only high temperature in summer, also the humidity is so high (humidity is 70-85% in the summer of Shenzhen City), flux and solder powder will increase the adsorption of water molecules, and due to water is electrolyte of the galvanic cell reaction, it will aggravate the hydrolysis of flux, stimulate the activity of flux, then finally the reaction on the surface of the solder powder is aggravating, and the vicious cycle eventually changes the physical properties of the solder paste.

Then how to solve this problem?

Warm up solder paste before using

Generally, in order to slow down the reaction of flux and solder powder, as well as extend the storage period, the solder paste needed to be stored in a refrigerator with 2-10^oC degree. So before using, it is better to take out solder paste and put in standard room temperature for warming up first. A can of 500g solder paste need to be rewarmed at least 2 hours, to make sure its temperature is the same as rooms’. (Normally that period of warming up time is 4 hours in Best Technology.) Otherwise, insufficient warming up will cause the water vapor in the air to condense and enter the solder paste due to the temperature difference, and result in solder paste be dry finally.

Environment temperature and humidity

The best storage temp of solder paste is 2-10^oC, but the recommended working environment temp is 20-25^oC, relative humidity is 30%-60%. (There’re additional humidifiers in the workshop of Best Technology, to make sure suitable humidity in the dry season such as Winter and Spring, and of course the air conditioner in Summer time to decrease the humidity) Usually, the rate of chemical reaction will approximately double, as the temperature increases by 10℃, so the high temperature will increase the volatilization of the solvent in the solder paste and the reaction speed of flux with powder, so the solder paste is easily to be dry. Meanwhile, low temperature will affect the viscosity and expansion of solder paste, and then will cause the poor soldering. At the same time, high humidity will also greatly increase the water vapor entering the solder paste; However, low humidity also affects the volatilization rate of solvent in solder paste.

For those solder paste that became dried already, it is better to dilute with flux provided by manufacturer of solder paste.

In a word, when use and store solder paste, we should pay more attention to its temperature & humidity, to make sure high quality of SMT can be achieved. Pls contact Best Technology if you have any questions or comments on solder paste, or SMT.

X-ray Inspection in PCB Assembly

Wednesday, June 15th, 2022

X-Ray Inspection’s Definition

X-ray inspection is a technology used to inspect the hidden features of the target objects or products. As for PCB inspection, X-ray is commonly used in the inspection of PCB assembly in order to test the quality and find the hidden defects, X-ray inspection is one of the most important steps for quality-oriented PCB manufacturers.

X-Ray Inspection’s Working Principle

Generally, there are three elements in the X-ray devices.

X-ray tube—to generate the X-ray photons.
Operation platform—to move along with the sample so that the sample can be inspected from different angles and magnification.
Detector—it can capture the X-ray through the samples and then transfer it into the image so that we can find out whether there are defects on the printed circuit board.

The Hidden Defects that can be Identified by X-Ray

Since PCB has the higher density with the solder joints hidden and holes buried or blind, X-ray enable us to inspect the quality of the PCB and identify various hidden defects. And there are three common hidden defects that can be inspected by X-ray.

Solder bridges—it is a common issue that will occur when the solder joints are so close that they create a connection which is not allowed. And usually, the solder bridges will be covered by some components on the PCB. But they can be easily found with the help of the X-ray device.
Solder voids—when gas or flux is entrained during welding, solder voids will be produced, which will lower the thermal conductivity at the solder joint and may cause physical defects. And X-ray can help to identify the solder voids
Pin-hole fills—pin-hole fills issue is a common problem occurring in the plug-in components on the printed circuit boards. The X-ray device can be used to identify these errors, and can even quantify the missing filling amount.

Our X-Ray Inspection Device

The maximum size of the board that can be put in the device’s operation platform is 510*430 mm, while the maximum inspection size of the device is 435*385 mm. So here is the manifestation of the operation platform’s function. When the size of PCB is over 435*385 mm, the operation platform will move along with the board so that the board can be inspected thoroughly.

And here is a video about operation of our X-ray inspection device.

So, this is the end of this article. In case if you have any questions, you are welcome to contact us via email at sales@bestpcbs.com. We are fully equipped to handle your PCB manufacturing requirements.

Electrostatic’ s Power-Trivia Series 2

Monday, April 18th, 2022

Last time we have known that electrostatic discharge (ESD) account for the highest proportion of causes leading to the failure of high electrostatic sensitive devices and the generation of it. Therefore, today we are going to talk about what kind of damage the static will cause to the Printed Circuit Board and how to avoid it.

The Influence of Electrostatic

Under different circumstances, the electrostatic voltage carried by the human body ranges from hundreds of volts to thousands of volts. And when people touch the electronic components, there will be ESD, resulting in the damage to devices and the reduction of reliability. To make matters worse, ESD will break down the device and directly scrap the product.

Besides, the ESD will lead to a large pulse current, which will generate a lot of heat in the chip and printed circuit board, making them burn out. Moreover, the integrated circuits (IC) are built with denser lithography lines than before so that their ability to withstand electrostatic discharge becomes weaker. Therefore, it is necessary to prevent it.

Elimination of Electrostatic

Since the static will has a great impact on the PCB and electronic components, it is extremely significant to take precautions against the electrostatic by taking some measures. And here are some measures carried for eliminating the electrostatic in our workshop.

Putting on anti-static clothes and hats. It is to prevent static existing in clothes and hair from influencing the board.

Wearing anti-static wrist straps. The principle is to discharge the static from the human body to the ground through the wrist strap and grounding wire.

Using static elimination instrument. What we have to do is to put just one hand on static elimination instrument, and do not leave our hand from it until the red light turns to green, which aims to eliminate the static existing in our body.

Keeping a certain humidity in the workshop. Higher humidity is not prone to ESD. The higher the humidity is, the easier it is to conduct electricity. As a result, electrostatic cannot be stored in our body.
Using anti-static packaging. When packaging, we have different packaging ways, such as anti-static bags, anti-static bubble film and so forth. And what to be used in packaging is up to our clients.

To sum up, electrostatic will cause damage to the Printed Circuit Board and electronic components so that it is necessary to take some measures to prevent it.

And this is the end of this trivia. If you would like to know more about PCB, you are welcome to contact us.

What Should be Prepared Before Starting the SMT Process?

Tuesday, February 15th, 2022

SMT, whose full name is Surface Mounted Technology, is the most popular technology in electronic assembly industry. It refers to process on PCB (Printed Circuit Board), putting various electronic components on PCB, such as resistors, capacitors, inductors, and so forth. Also, there are some dos and don’ts in the whole process of PCBA.

As noted previously, there are all sorts of electronic components that will be used in the assembly process of Printed Circuit Board. Therefore, it is extremely important to take some measures to keep a check on static. Here are three steps before entering the SMT workshop.

First, put on anti-static clothes and hats. It is to prevent static existing in clothes and hair from influencing the board, for static has a potential and tremendous destructive power.

Second, what we have to do is to put just one hand on static elimination instrument, and do not leave our hand from it until the red light turns to green, which aims to eliminate the static existing in our body.

Third, across the air shower door. In this way, dust that is invisible on our body can be blown off in about 5 seconds.

Only finishing the three steps above can we enter the PCB assembly workshop. And after entering the workshop, there are also something needed to be prepared.

Solder paste. The storage temperature of solder paste is 2-10 degrees Celcius, hence it has a period of regaining temperature, which conducts in the rewarming machine for 4 hours. Then the solder paste should be rabbled in a blender for 5 mins in order to help three ingredients in it to be fully integrated, which can help to achieve a better printing and back-flow soldering effect.

Oven. This machine is used to get rid of the moisture from materials or boards, ensuring that PCB will not be defective due to moisture during the subsequent assembly process. Moreover, different boards have different requirements. But generally, the baking parameter is 105 degrees Celcius, lasting 1.5 hours.

Dryer. It is used to maintain a set temperature and humility of materials and boards that needs to be processed that day, which is also to avoid that moisture does harm to materials and boards after removing the moisture by oven.

Tension test of stencils. Before manufacturing, the stencils’ uniformity should be tested by tensiometer, which mainly tests the four corners and the center part of the stencil, guaranteeing the solder paste printing quality. And the parameter should be between 30 and 45.

To sum up, although there are lots of preparations should be done before starting the formal assembly process, each of them is significant, for they will probably influence the quality of boards directly. Besides, only a good preparation can make a certain that the follow-up process can keep going. Thus, it is a must to prepare well in advance.

And Best Technology is an experienced electronic company. It not only can provide PCB A service, but can provide other services, such as FPC, FR4 PCB, Rigid-flex PCB and so on. And if you have any questions about SMT, or any other questions about assembly, you are welcome to contact us.

Via Tented, Via Filled & Via Plugged

Monday, December 20th, 2021

Via Tented, Via Filled (filled with solder mask) & Via Plugged (Via In Pad â€“ Conductive material or Non-Conductive material)

One of the most confused idea during our PCB design is the difference between Via Tenting, Via Filling and Via Plugging. Designers often get mixed up between them and fail to take full advantage of the process.

Today, let us discuss them, so that you can be confident in specifying your design requirements clearly when submitting PCB files to Best Technology before final manufacturing.

Via Tented

What is via?

A plated through hole (PTH) in a Printed Circuit Board that is used to provide electrical connection between a trace on one layer of the Printed Circuit Board to a trace on another layer. Since it is not used to mount component leads, it is generally a small hole and pad diameter.

A. Three methods and definitions of via processing

There are three methods for via processing: via hole opening & via hole cover oil & via hole plug oil

1. Through hole opening window: it is the tin on the solder ring of the via (the tin is exposed like a plug-in pad). The window is usually used to debug the measurement signal. The disadvantage is that it is easy to cause a short circuit.

2. Through hole cover oil: it is the welding ring of the through hole (via) covered with solder mask ink

3. Through hole plugging oil: refers to plugging the hole with ink.

Secondly, the inspection standards for a processing method

1. Through-hole opening window is like a plug-in pad, and the window is sprayed with tin. Inspection standard: tin can be tinned, and tin can be easily tinned.

2. The inspection standard of the via hole cover oil: it is not easy to tin in the patch.

3. Inspection criteria for via plug oil: First, it must be opaque, and it must be covered and blocked by ink.

Finally, we are talk for comparison and distinction between via hole cover oil and via hole plug oil:

1. Via plug oil This process is an important supplement to via plug oil, so generally high-quality boards will require via plug oil. And often many engineers who are just entering the industry are stupid and unclear. So how do you distinguish between the two?

2. The requirement of via hole cover oil is that the ring of the via hole must be covered with ink. The emphasis is to ensure the thickness and coverage of the ink on the edge of the hole. The key control is that the ring does not accept false copper exposure and orifice oil. Thin

3. Through hole plugging oil is the production of plug holes with ink inside the holes of the through holes. The emphasis is on the quality and density of the plug holes. After the holes are plugged, no light can be transmitted.

4. The method of plugging the via hole is to first fill the via hole with ink to block the via hole, so that the ink on the solder mask will not flow into the via hole, so as to achieve the situation that the via hole does not appear yellow. (If you have strict requirements and place an order for via hole cover oil, the cover oil is usually not full or yellowish, you can change it to via hole plug oil later). In addition, the smaller the vias are, the easier it is to plug them. The vias of the fortress oil are not easy to be too large (the circuit board proofing plugging oil is directly plugged with ink, and the printing tape is plugged. It is recommended that the vias that need to be plugged are designed to be <0.5mm. This is also free; no additional money is required).

If you have more question Via Tented, Via Filled& Via Plugged, warmly welcomed to contact Best Tech for more FR4 design service.

PCB & MCPCB – Best Technology

Archive for the ‘PCBA’ Category

What You Know About Counterbores in PCB Design and Manufacturing

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5 Tips Tell You How to Solder BGA Better in PCBA

What is BGA Soldering?

The Importance of BGA Soldering in Electronics Manufacturing

Challenges Faced in BGA Soldering

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5 PCB Testing details to make your PCB no more quality issues

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