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Types of Vias

May 20th, 2022

What is via?

A via plays an important role in multi-layer PCBs. It is used to make an electrical connection between the layers of a multi-layer PCB. Generally speaking, every hole in the printed circuit boards can be called as via.

A via is constructed by placing copper pads on each layer of the PCB and drilling a hole through them. And the hole is plated with copper that forms electrical connection through the insulation that separates the copper layers.

PCB Vias

Types of Vias

There are three main types of vias used in PCB: through-hole via, blind via and buried via.

Through-Hole Via

Through-hole via goes right through the printed circuit board from top to bottom and can be used to connect all the layers of a PCB. It is the most common via and is easiest to construct.

Blind Via

Blind via connects the outermost layer of a PCB to the next layer. Namely, it cannot be seen on the other side of the board and is therefore called blind via.

Buried Via

Buried via is used to connect internal layers of a PCB. And it cannot be seen on the surface of the board.

Via Types

In addition, it is always better to use multiple smaller vias rather than one large via since smaller vias can reduce the inductance and also provide an additional path to the current flow in case any of the vias fail.

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.

Types of Metal Bases Utilized in MCPCB

May 10th, 2022

What is metal core printed circuit?

Metal core printed circuit board is abbreviated as MCPCB. And namely, the core or the base material of MCPCB is a metal instead of the traditional FR4/CEM1-3.

Types of metal bases used in MCPCB

The metal cores of the thermal PCB can be aluminum, copper and steel alloys. Apart from being cheaper than copper, aluminum is known for its good heat transferring and dissipation abilities, which is the most common used. However, copper is considered to be a better performer. So, why does the aluminum become the first choice for the material of the MCPCB?

Aluminum base—The aluminum PCB offers good heat dissipation and heat transferring ability. Since they are also light in weight, the aluminum core PCBs are widely used in LED products.

Aluminum Core PCB

Copper base—The copper core board features a better performance than aluminum. But customers will usually choose the aluminum instead of copper, for it is relatively expensive. Also, compared with the aluminum, the copper is heavier and involves a tough machining process.

Copper Core PCB

Various base metals and their properties

Metal Base MaterialThermal Conductivity
(W/m-K)
Coefficient of Thermal Expansion
(µm/m-°C)
Aluminum88-25125
Copper38617

Based on the table, it can be known that although the thermal conductivity of the copper is better than that of the aluminum, its ability of thermal expansion does not perform better than the aluminum.

Therefore, there are some reasons why the aluminum is the first choice for the material of the MCPCB, including the lower cost compared to copper, light weight, excellent durability and its heat transferring capabilities.

And these are also the reasons that the MCPCB is widely used in the LED products as we mentioned in the last article.

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 or MCPCB manufacturing requirements.

Why is the MCPCB Widely Used in the LED Products?

April 30th, 2022

MCPCB refers to metal core printed circuit board. It has a good performance in heat dissipation, so it is often used in LED products.

The advantages of MCPCB

Prevent overheating: 

LEDs tend to get overheated very quickly. If a metal core printed circuit board is used, it solves overheating by transferring the energy from one side to another.

Improve the material’s reliability: 

The MCPCB plays a key role in the elements that heats up overly at times. It helps to divert the heat from one side to another where the heat has vanished, which improves the product’s life, making it much more durable.

Adapt to a high temperature: 

Unlike the FR4 technology, the metal core printed circuit board can adapt to products with a high temperature, hence it proves to be very useful for LED products.

LED PCB

Why is the MCPCB widely used in the LED products?

Since it is well-known that the LED products will emit a lot of heat. Based on the advantages, the metal core PCB can transfer heat quickly and prevent overheating. And Aluminum PCB is mostly used in metal core PCBs, for they can operate longer than other metals and longer shelf life.

Moreover, metal core PCB has a high conductive ability, hence there remains ample space for maximum LEDs, which allows producing sufficient light and achieving high performance.

Therefore, based on the advantages of the MCPCB, it is the prior option of the material for the LED products.

So, this is the end of the 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 or MCPCB manufacturing requirements.

3M Epoxy Adhesive DP190-Gray & 3M Epoxy Adhesive DP190-Translucent

April 22nd, 2022

Both 3M Epoxy Adhesive DP190-Gray and 3M Epoxy Adhesive DP190-Translucent are a two-part epoxy adhesive that delivers exceptional performance with high shear and peel strength.

They can bond to a wide range of materials, such as metals, ceramics, wood, fiberboard, glass, rubber and many plastics. So, PCB is no exception. But what are the similarities and differences between them?

Similarities

  • Provide tough, strong bonds through high shear and peel strength.
  • Capable of bonding to a wide variety of different materials.
  • Deliver extended work-life, providing additional time for adjustment.
  • Exhibit good environmental aging properties, delivering long-term durability.

Differences

3M Epoxy Adhesive DP190-Gray has a moderately high modulus. With a 90-minute work-life, it reaches handling strength in approximately 10 hours and full cure in 7 days at room temperature.

Additionally, this epoxy adhesive has medium viscosity and self-leveling with a 1:1 mix ratio by volume. But its flexibility and elongation are moderate.

(3M Epoxy Adhesive DP190-Gray)

3M Epoxy Adhesive DP190-Translucent has a moderately low modulus. With an 80-minute work-life, it reaches handling strength in approximately 10 hours and full cure in 14 days at room temperature.

It has low viscosity and self-leveling with a 1:1 mix ratio by volume. Additionally, it features high flexibility and elongation.

3M Epoxy Adhesive DP190–Translucent

This is all about the similarities and differences between the 3M Epoxy Adhesive DP190-Gray and 3M Epoxy Adhesive DP190-Translucent. It is supposed that you have known about them.

But if you still have any questions about them or PCB, please feel free to contact us. Because at Best Technology, we are fully equipped to handle your PCB manufacturing requirements.

Thermal Conductivity—Aluminum PCB vs Ceramic PCB Series 2

April 19th, 2022

Last time we have talked about the structure difference between the aluminum PCB and ceramic PCB. So, based on the different structures, whose thermal conductivity is better?

We have known that a single layer aluminum PCB is made up of copper layer, dielectric layer and aluminum layer. Meanwhile, the dielectric layer is the decisive factor affecting the thermal conductivity.

Generally, its thermal conductivity ranges from 0.8 to 3.0 W/m-K, but can up to 8.0 W/m-K. So, in terms of heat dissipation, the aluminum substrate does much better than FR-4 substrate. And it is a good choice for LED lighting products with high power.

Aluminum PCB

However, the heat-conducting property of ceramic PCB is superior to that of the aluminum PCB.

Since ceramic itself is an insulating material with a great heat-conducting property, it does not need a dielectric layer. Therefore, the heat can be dissipated directly through the ceramic.

Because of its excellent performance in heat dissipation, it is particularly suitable for the lighting product with ultra high power and those products which have a high demand of heat dissipation.

Ceramic PCB

To summarize, clearly, we can know from the table below that ceramic PCB does better than aluminum PCB in terms of thermal conductivity and heat dissipation. And this is mainly because of the dielectric layer, which is related to the functions of bonding, insulation and heat conduction.

The better the heat conduction performance of the insulating layer, the more conducive it is to the diffusion of heat generated during the operation to the device, hence it will be more conducive to lower the operating temperature of the device. That is to say, aluminum PCB will be subject to the dielectric layer, while ceramic PCB will not be restricted.    

And, this is the end of the comparison of the thermal conductivity between aluminum PCB and ceramic PCB. If you still have any questions about them, please feel free to contact us.

Electrostatic’ s Power-Trivia Series 2

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.

PCBA

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.
Anti-static Clothes and Hats
  • 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.
Anti-Static Wrist Strap
  • 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.
Static Elimination Instrument
  • 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.
Anti-static Bags

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.

Electrostatic’ s Power─Trivia Series 1

March 23rd, 2022

The Introduction to Electrostatic

Static, the excess charge on an object, is a phenomenon caused by the unbalanced distribution of charge in the material system. When an object is charged, the charge will remain on the object unless it is removed by other objects, so it is called “static electricityâ€.

As is known, we cannot touch PCB directly with our hands because of the electrostatic. But most of people have thought lowly of electrostatic’ s power, deeming that it is not strong enough to be harmful to some devices, especially electronic components.

On the contrary, electrostatic can be in some way devastating. According to the statistics, electrostatic discharge (ESD) account for the highest proportion in the ranking of causes leading to the failure of high electrostatic sensitive devices, which is 59%.

Pie Chart

The Generation of Electrostatic

There are various ways resulting in the generation of electrostatic. But, triboelectrification, namely indicating that electrostatic is generated by friction, is the most common one.

Where there is friction, there will be electrostatic. When walking, the shoes will rub with the floor, leading to the triboelectrification. Also, the frictions between our hair and clothes are so easier to generate the static that every movement in the PCB workshop will unintentionally cause the generation of static.

Then the static generated will have a great impact on the PCB and electronic components. But, how great the electrostatic’ s power is, or in other words, what kind of damage can it cause to the printed circuit boards or electronic components? And what can we do to eliminate the electrostatic?

We will talk about it next time, hence if you would like to know more, you are welcome to contact us, or you can continuously follow our blog site, on which we will keep sharing more information about PCB.

Differences in Structure——Aluminum PCB vs Ceramic PCB Series 1

March 21st, 2022

It is supposed that we are familiar with both aluminum PCB and ceramic PCB. But if juxtaposing them, which one will be better by one tally? So, we are about to talk about some differences between them in terms of structure.

Aluminum PCB

Aluminum substrate namely uses aluminum as substrate, which has a good heat dissipation capacity. Generally, it is single-sided, and also can be double-sided while multi-layer aluminum PCB is a little bit hard to manufacture. Besides, a single layer aluminum PCB is made up of copper layer, dielectric layer and aluminum layer.

Structure of Aluminum PCB

Ceramic PCB

Ceramic PCB namely uses ceramic as substrate. Apart from the material, the structure is the biggest difference between ceramic PCB and aluminum PCB. Since ceramic itself is an insulating material, it does not need a dielectric layer. Its structure is as follows.

Structure of Ceramic PCB

Therefore, whether there is a dielectric layer is the main difference in structure between aluminum PCB and ceramic PCB. And dielectric layer plays an important role in thermal conductivity. So, what is the relationship between dielectric layer and thermal conductivity? And whose thermal conductivity is better between aluminum PCB and ceramic PCB?

We will talk about it next time. And if you would like to know the answer, please feel free to contact us, or you can continuously follow our blog site, we will keep updating more information about the differences between aluminum PCB and ceramic PCB on it.

What Should be Prepared Before Starting the SMT Process?

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.

Anti-static Clothes and Hats

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.

Static Elimination Instrument

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

Air Shower Door

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.
Solder Paste
  • 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.
Oven
  • 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.
Dryer
  • 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.
Stencils

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 PCBA 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.

Advantages of LED PCB Compared with Common Standard PCB

December 22nd, 2021

With the development of electronic products, the requirements of circuit boards applied in electronic products are becoming higher and higher. The volume of printed circuit boards is also shrinking exponentially, the assembly density is increasing, and the internal wiring of the line layer is becoming more and more intensive. Compared with PCB, LED PCB with metal core can achieve better heat dissipation effect.

LED PCB material:

First of all, LED PCB space utilization is higher, it takes up relatively small space, but can withstand relatively high-power output.

It is well known that when the power of the circuit board is high, high heat will be generated. If the heat cannot be dispersed in time, it may lead to the shortening of the working life of LED products, and the more serious consequence is the safety problem of the circuit board due to overheating.

Therefore, in order to make the LED lighting system longer life, it is generally used to print the circuit board with metal core, and the characteristics of the metal core is relatively large density, strong thermal conductivity, conducive to heat dissipation effect.

LED PCB board design:

The LED PCB is also unique in that its components are located on the surface, rather than through holes, because the metal core at the bottom dissipates heat more quickly.

LED PCB surface mounting

Some LED printed circuit boards have through-holes, especially multilayer metal core printed circuit PCB. Because the number of layers of the circuit board increases, the circuit layout is more complex, heat is more difficult to emit, and the existence of the through hole is to achieve faster heat dissipation. The drilling holes on the LED board are mounting holes, which are usually larger than the standard PCB through holes.

LED PCB solder mask color:

In addition, LED printed circuit board solder resistance layer color is also its characteristics.

The color of solder resistance layer on the LED printed circuit board is usually white, while the PCB board has a series of colors such as black, green and red and so on. This is also determined by the characteristics of LED boards in practical applications. Since LEDPCB board is usually used as backlight board, photosensitive solar ink is usually coated on the surface of the circuit board. White Taiyo Solder mask can achieve high temperature resistance, not easy to change color, high reflectivity, so as to achieve the reflection effect of lighting and better lighting effect.

LED PCB