How to do SMT for ceramic PCB

May 19th, 2021

As we all know if ceramic PCB is very fragile, so it is not easy to do SMT for them.

But we can do the SMT for ceramic PCB easily because we do it every day and we have more than 15 years experiences for doing that.

For the almost SMD components (such as SMD rsistors, capacitors, diode etc), normally we will add the solder paste by using SMT stencil, then put the components by machine, finally do the oven reflow.

For some special components, we will need to solder it by hand, such as through connectors, but it can’t be soldered by hand directly, it need to be put on the heating table to keep the temperature is high enough to make the solder past at melt state. Because the ceramic material with very good heat dissipation, the solder paste will be solidification very easily if don’t put the ceramic PCB on heating table

For some small LED, it can’t be put by SMT machine, because no such small feeder to pick it up, then need to put it on board by hand.

We can do very well for the small BGA components too.

Below some photos of ceramic PCB.

If you would like to know more about ceramic and ceramic PCB SMT, please feel free to email me

Ceramic PCB with SMT 1
Ceramic PCB with SMT 2
Ceramic PCB with SMT 3
Ceramic PCB with SMT 4
Ceramic PCB with SMT 5

Aluminum vs Copper Core PCB

May 19th, 2021

In Best Technology, currently the most common metal used for Metal Core PCB manufacturer are Aluminum, Copper. Today let’s talk about the main differences between aluminum substrate and copper substrate, hoping to help you choose the right substrate in future design projects.

Although they both share similar properties and functions, there are still a few variations between the two kinds of metals. Some of the key differences between aluminium and copper core PCBs are explained in the points below.

1. Thermal Conductivity

The thermal conductivity of copper substrate is up to about 400(W/mK) and the thermal conductivity of aluminum substrate is generally about 200W(W/mK). The thermal conductivity is higher, the transfer efficiency will be better, and the heat dissipation will be better, then the working life will be longer.

 Thermal Conductivity

2. Electrical Conductivity

Both aluminum and copper, being metals, are electrical conductors of electricity, although the exact degree of this varies between the two metals. When it comes to electrical conductivity, copper has a clear advantage over aluminum. In other words, in applications where there is a need for efficient electrical conductivity, copper makes for an ideal pick.

 Electrical Conductivity

3. Electrical Resistance

Resistance is very important when it comes to PCB design, as it can have an effect on the overall function and stability of the component. Given that copper has a higher density than aluminum, it tends to have a lower resistance than aluminum, so copper is an better choice where there’s a requirement for thinner circuits and faster electricity transfer.

Electrical Resistance

4. Weight

Since copper has the higher density for per unit area, the weight of copper PCB is much heavier than aluminum PCB for the same design.

In applications where light-weight construction is required more than anything else, aluminum is the preferred material of choice. On the other hand, applications where weight is not much of an issue, tends to be the ones where copper is widely used.

Weight

5. Application

Copper core PCB is the best heat dissipation among all MCPCB, so it’s mostly used in automobile headlights, taillights and some high-tech electronic products (unmanned aircraft, mining machine) high-power lighting equipment. The aluminum core PCB is mostly used in indoor lighting, energy saving lighting, street lighting and other energy-saving lighting electronic products.

Application
Application

In conclusion, due to the above different parameters and performance, the cost of copper is generally more expensive than aluminum. If you have other questions about MCPCB, welcome to contact us .

How to Test for an Open Short Circuit on a PCB?

May 18th, 2021

Every printed circuit board need to do full test before ship to our customer. but you may have doubt, the PCB was made according to the original Gerber file, why finish the PCB production process, why the short Circuit will occur on a FR4 circuit board?

A short circuit may also occur during reflow soldering. the solder paste may accidentally connect two pins that are very close to each other. In some cases, errors can occur during the PCB design process because the wiring between different networks accidentally connects.

We believe every PCB manufacture have their own test method to do short circuit, but today I would like share how Best Technology to Check for Short Circuits in a Printed circuit board.

Here are some important steps:

Step 1 Visual inspection

The first step for locating short circuits on PCB is to carefully look at the entire surface of the PCB. Best Technology QC guys use a magnifying glass or low magnification microscope during the circuit board examination. We check the whole board surface to see if there are some traces break off. Any cracks or blobs of solder should get careful attention. Check all your vias. If you specified unplated vias, make sure that’s the case on the board. Poorly plated vias can create a short circuit between layers and leave you with everything tied to ground, VCC, or both.

visual inspection

All the testing work will carry out according to IPC 6012 class 2.

Step 2 Use a Digital Multimeter to find out where is the problem

To test a circuit board for a short circuit, you need to check the resistance between different points in the circuit. If visual inspection doesn’t reveal any clues as to the location or cause of the short circuit, grab a multimeter and try to track down the physical location on the printed circuit board. The multimeter approach gets mixed reviews in most electronics forums, but tracing your test points can help you figure out what isn’t the problem.

Step 3 use Probe flying Tester &E-tester

As long as you are in Printed Circuit board field, you are definitely known Probe flying test and E-Teter.

Flying probe test systems require no test fixture, it can serve both prototype and small production, providing maximum flexibility for PCB manufacturers and this job can complete in a short time.

probe flying test
probe flying test-1

But when your circuit board become to volume, you will need to open a test tooling/test fixture to test the Printed Circuit board to test the open short circuit.

E-tester

In my next blog in June, I will introduce Probe flying test to you in more detail.

If you have any question about printed circuit board, you are welcome to contact Best Technology.

It is our great pleasure to communicate with you for any issue for printed circuit boards.

What’s fiducial marks on the PCB?

April 24th, 2021

You may ever be recommended by some PCB manufacturers to add the fiducial holes on the board edge. Do you know what is fiducial marks and what’s the purpose for this kind of holes in a PCB?

Now, let me to show you something for what is the fiducial holes.

Fiducial holes, we also call it fiducials mark, while we assemble a PCB, it will need to locate the positions for each component, and it is positioned based on the fiducial mark as the reference point.

There are 3 types fiducial marks, first type is fiducial marks on a single board, second type is the fiducial marks on a PCB panel, third one is the fiducial marks for some single component on the board.

Here are the pictures for you to understand the types of the fiducials.

Fiducial holes types
Fiducial holes

Fiducial mark on a single board is designed for positioned all circuits features on a single board. It is necessary to have a fiducial mark on a single board.

And fiducial marks on a PCB panel is used to assist positioning the circuits. 

For the fiducial mark of a single component, it is designed to position the fiducial mark of a single component, which can improve the placement progress (For QFP, CSP, BGA and other important components must have the fiducial marks).

So, it is important to add the fiducial holes on a PCB board.

Also, while we make the panel for the PCB board, on the diagonal of the four corners, it is required to have 2 fiducial points at least on 2 diagonal corners.  you can also place 4 marks on the four corners, but generally, assembly plant will only need 2 marks for recognize.

See below a PCB panel for reference:

PCB panel drawing Best Technology
Fiducial holes on a panel

In the other hand, while you design the PCB, please try not to put the silk screens, pads, traces etc. within 2mm of the optical fiducial marks. Otherwise, the SMT machine will not be able to recognize the optical fiducial on the PCB boards.

And if you add the fiducial holes on the area which without any circuits, to avoid the holes being etching while the process, so generally we suggest to add a metal circles around the fiducial holes, to make it more obviously on the boards.

If you have any new PCB design which you also want to add the fiducial marks.

You are welcome to contact Best Technology for a help and we will show our best help for you.  

What’s the differences between thick film ceramic PCB and DPC ceramic PCB

April 21st, 2021

Ceramic PCB including Alumina PCB (Al2O3 PCB), Aluminum Nitride PCB (AlN), Bryllium Oxide PCB(BeO PCB) etc.

There are other differences except the substrate material is different.

  1. The method of making conductor is different.

The conductor for thick film ceramic is made by printing, but DPC is made by vacuum sputtering and plating.

  • The conductor is different.

The conductor for thick film ceramic PCB is Au or AgPd, but for DPC ceramic PCB, it is copper.

  • The thickness of conductor is different.

Normally, it is 10-20um for thick film ceramic PCB, copper thickness can be 10um-300um for DPC ceramic PCB.

  • The solder mask is different.

It is glass glaze for thick film ceramic PCB, the most popular color is greenish and blue. Glass glaze can withstand very high temperature, up to 850C

It is normal solder mask oil for DPC ceramic PCB, the most popular color is white.

The above is only simple introduction for the difference, if you want to know more differences between thick film ceramic PCB and DPC ceramic PCB or other details about ceramic PCB, please contact us

Why do MCPCB board have holes? What is PTH/NPTH?

April 15th, 2021

If you look closely at a MCPCB board, you will see holes of different sizes in the board, each hole was designed for a purpose. These holes can be divided into PTH (Plating Through holes) and NPTH (Non-Plating Through holes). Best Technology’s smallest drill tool is 0.5mm, so generally we require customers to design the minimum hole size of 0.5mm or more.

How to distinguish PTH and NPTH through holes?

In fact, it is very simple. Just look at the hole wall to see if there are bright plating traces (Copper). The holes with copper are PTH, and the holes without copper are NPTH.

PTH & NPTH

What is the NPTH used for?

If you pay a little attention, you will find that the size of NPTH is usually larger than the PTH, because most of NPTH are for positioning purposes, it can be divided into the following four types.

  1. 1) Countersink: It’s a cone-shaped hole that is cut into the PCB to allow the flat head of a socket cap screw to fit flush with the surface of the board.
  2. Counterbore: It’s a cylindrical flat-bottomed hole that is designed to house a hex head or socket head cap screw to be used to secure a PCB board.
Countersink & Counterbore
  • Screw hole: As shown below.
As shown below
  • Slot hole: Some components of the installation and positioning of the foot is rectangular or oval, we called this kind of irregular drilling as slot hole. During PCB machining, there are two types of drilling tools for plugins, one is called a drill cutter, which is used to drill round holes, and the other is called a routing bit, which is used to drill slot hole.
Slot hole

What is the PTH used for?

In order to connect the circuits between two or more layers, we need to design the PTH, which have following three main purposes.

  1. Used for conducting electricity.
  • Used for heat dissipation.
  • Used for plug-in components.

If you have other questions about MCPCB, welcome to contact us

What is Blind Via and Buried Via for Printed Circuit Board?

April 15th, 2021

In the Printed Circuit Board industry, believe that you are familiar with blind via and buried via. What is blind via and buried via for PCB? And do you know is the Blind via or Buried Via have special application in your Printed Circuit Board?

In order to know more, we would like to share more information with you today.

Best Technology is an experienced FR4 PCB manufacturer in China since year 2006, with more than 15 years design and fabricate experience for PCB, Best Technology accumulated more than 1000 customers from all over the world.

Before start, we need to know what kinds of hole for FR4 Circuit Board, Via, Blind Via and Buried Via.

What is a Via?

Vias are the copper-plated holes in the PCB that allows the layers to layer connection. The standard via is called a through-hole via, but there are several disadvantages to using through-hole vias in Surface Mount Technology (SMT). For this reason, we often use a blind via or buried via instead. A blind or buried via can be processed in a wide range of different measures, including plugged copper mask via, a plugged solder mask via, plated via or staggered via.

Via
staggered via

What is Blind Via?

The via connects the external layer to one or more inner layers of the PCB and is responsible for the interconnection between that top layer and the inner layers.

Blind Via

What is Buried Via?

For a buried via, is the inner HOLE, between both sides in the board up and down inside the layer after pressing is cannot see. So, it doesn’t have to take up the outer area.

Buried Via

Blind and buried vias are particularly advantageous in HDI board because they optimize the density of the boards without increasing board size or the number of board layers you require. They are most commonly used in high-density PCB designs like, or in FPGA and custom chip packaging.Here is the photo which Best Technology took from our production line to make HDI Printed Circuit Board for our USA customer.

HDI board under production
HDI process

Best Technology is a very professional manufacturer in printed circuit board and HDI Board. If you are interesting to know more information of us, come to contact us and we are looking forward to discuss with you more for Printed Circuit Board.

Interesting color matching – Silkscreen and Solder mask

March 23rd, 2021

In Best Technology, solder mask and silkscreen are available in a variety of colors. For example, common colors of solder mask are black, white, blue, green, red. Common silkscreen colors are black, white, yellow, red, blue. Generally according to the different needs of customers to use collocation, but sometimes if the color collocation is not appropriate will produce color difference.

The following is a list of common collocations that we recommend based on our experience for your future project design.

Solder maskRecommended Silkscreen
BlackWhite
WhiteBlack/Blue/Green/Red/Yellow
BlueWhite
GreenWhite
RedWhite

For the most part,the color of solder mask doesn’t have any effect on PCB’s

functionality.But if the color of the silk screen does not match properly,which may

Cause chromatic aberration(for example,a yellow silkscreen on a black solder mask,

The silkscreen visual may look green)or make reading the silk screen more difficult

To read(for example, a black silkscreen on a light black solder mask).The solder mask will also affect your ability to visually inspect the PCBs. Below are the solder mask comparison from the highest contrast to the lowest for your reference.

Green

Most customers will choose to use Green solder mask for their project since Green is easy on the eyes and allows for high contrast between traces, planes, and empty space on the PCB. Green solder mask has become an industry standard. High contrast allows technicians to most easily review for manufacturing defects.

green

Red

A Red solder mask will provide a bold and clean looking PCB, however the contrast between traces, planes, and empty space significantly lower than it is with a green solder mask. Magnification may be needed when inspecting fine traces on the board for defects with a Red mask. White silkscreen will be better than black silkscreen on a board with red solder mask.

red

 Blue

Blue solder masks have even lower contrast, and magnification becomes required when inspecting for manufacturing defects. These PCBs look visually pleasing and professional and are a good choice for fully-developed products that will not require trace visibility.

blue

Black

Black masks have almost no contrast between traces, planes and empty space. A Black mask will absorb heat, increasing the danger of overheating for sensitive components. Pay attention that in order to avoid the appearance of color difference as far as possible do not choose the silkscreen like yellow, green, red, or blue. White will be the better choice.

black

White

A white mask will be the hardest to clean, and also has the lowest contrast. If possible, we suggest that you avoid choosing white, especially in the prototyping stage. It’s the best choice to use white solder mask for LED board, following pictures for your reference.

whtite

If you have other questions about solder mask, welcome to contact us. (Email:sales@bestpcbs.com), we will prove you professional suggestions and solutions.

The Advantages of Surface Mount Technology of a printed circuit board

March 19th, 2021

Surface-Mount Technology has been the industry standard for assembling printed circuit board. It has maintained its popular due its wide array of advantages and relatively few drawbacks. For more than 15 years’ experience, Best Technology has been offering surface-mount service for worldwide customers, and SMT service become a great part of our business.

See some photo which we are do assembly for our customer this month.

SMT 1

Top Advantages of Surface-Mount Technology

Smaller size and reduced weight are the two main advantages to SMT. Components can be aligned closer together and end products will be more compact and light weight.

SMT 2

Here are additional benefits of SMT:

1.Component placement auto correctly â€“ there is no alignment between the PCB solder pads and components pads to avoid placement errors.

2.Low cost:

The advantage of small size up to 0201. One set, SMT typically requires lower production costs than through-hole placement. The size of the board is reduced, the number of drilled holes is reduced, and routing of traces is reduced. So bring down the cost of the whole project.

3.Design flexibility â€“ You can combine through-hole technology and SMT manufacturing on the same board for greater functionality.

4. Printed circuit boards created with the SMT process are more compact, providing higher circuit speeds. (This is the main reasons most manufacturers choose for this method.)

5.Higher circuit speeds â€“ Most manufacturers rate this the number-one benefit.

Lower resistance/induction â€“ High-frequency performance reduces unwanted consequences of RF signals.

6. Quick Turn Around

Using Surface-Mount Technology, it can save lots of time, SMT is a much more streamlined manufacturing process compared to through-hole. Time is saved because components are applied using a solder paste instead of drilling holes in the PCB

7. Quantity â€“ More components can be positioned using both sides of the circuit board, creating more connections for each component. Fewer circuit boards are needed for devices.

8. Stability â€“ Better performance delivery is realized with vibration mechanical conditions. SMT connections are more reliable, it can reduce the dis connection risks during the final test.

SMT 3

Best Technology offers expert surface-mount technology services in China, along with manufacturing bare printed circuit board, flexible circuits, and MCPCB fabrication. With more than 15 years rigid PCB board experience, Best Technology has the resources, equipment, and know-how to produce your PCBs quickly and reliably.

different assembled board photo

Call Best Technology now and let us become your partner of PCB assembly service.

High-TG FR4 Printed Circuit Board

December 31st, 2020

If you work in Printed Circuit Board industry, you may know a normal PCB FR4-Tg is 130-140 degrees, the medium Tg is greater than 150-160 degrees, and High-TG FR4 Printed Circuit Board is greater than 170 degrees.
And what is a High-TG FR4 Printed Circuit Board? High-TG PCB is another name for a high-temperature FR4 PCB, it means the printed wiring boards designed to endure for extremely high-temperature. A Printed Circuit Board is defined as high-TG FR4 PCB if its glass transition temperature (TG) is higher than 170 degrees Celsius. High-TG FR4 will have better mechanical and chemical resistance to heat and moisture than standard FR4. The higher the TG value, the better the temperature resistance of the material, so High-TG FR4 is more and more popular particularly working in high power industry.
Best Technology can provide many different High-TG FR4 material for Rigid Circuit board, Typical High-TG FR4 PCB material including: ITEQ-IT-180A, ISOLA 370HR, ShengYi S1000-2 and etc.

Part of the inventory of raw material-1
Part of the inventory of raw material-2
Part of the inventory of raw material-3

From the following PCB picture, you can see the normal TG130 FR4 PCB substrate is not only softening, deformation, melting, as well as other phenomenon working under high temperatures, but also there is a sharp decline in electrical properties, which will effect on product life.

Solder mask blistering-1
、Solder mask blistering-2

If your FR4 Printed Circuit Board or PCBA board appear to above problems, then you should consider to use a High-TG FR4 Rigid Circuit Board. it may be catching your interest willing to understand a little bit more about High-TG FR4 printed circuit boards. Because High Tg Rigid Circuit board have a better stability at high temperatures, the substrate provides better heat resistance, mechanical and chemical stability for the circuit board.

BPM20396)

Properties/ Applications of high Tg PCB
With the rapid development of electronics industry, High-TG FR4 PCB is widely used in Uninterrupted Power Supply, precise instrument as well as industry. High-TG FR4 PCB material probably designed for the high functionality, high multi-layer development high-density circuit; higher heat resistance and high-density surface mounting technology (SMT). So, the demand on High-TG FR4 PCB material become more widely used PCB manufacturing.
What’s more, High TG material is also popular in LED lighting industry, because heat dissipation of LED is higher than normal electronic components, but same structure of FR-4 board is much cheaper than metal core PCB, such as aluminum PCB.
High-TG FR4 PCB materials have the following properties:
 Resistance to high temperatures
 Long delamination durability (aging of materials to consider for safety reasons)
 Low thermal expansion
Excellent PTH reliability
Good mechanical properties
High temperature durability
High value of thermal stress resistance
high temperature durability
long delamination durability
Low Z axis expansion (CTE)

BPM19308

Advantages of High-TG FR4 PCB
Higher stability: it will automatically improve the heat resistance, chemical resistance, moisture resistance, as well as stability of the device if increasing the TG of a printed circuit board substrate.
Bear high power density designs: high TG PCB will be a good solution for heat management if the device has high power density with quite high heat generation rate.
It can achieve with using a larger printed circuit board to change the design and power requirements of a device when reducing the heat generation of ordinary board, what’s more, it also can use the high TG PCB.
Ideal for multilayer & HDI PCBs: there will lead to high levels of heat dissipation because multilayer & HDI PCBs are more compact and have dense circuits. So high TG PCBs are often used for the multilayer & HDI PCBs so that it can make sure reliability in Printed circuit board fabrication.

BPM20005 TOP
BPM20005 BOT

 If your applications are in any danger of subjecting your PCBs to extreme temperatures or the PCB is required to be RoHS Compliant, it will be in your best interest to look into high-TG FR4 PCBs.
Come to contact Best Technology Co., Limited. for High-TG PCB assistance. we can help you determine if you need high-temperature printed circuit boards and direct you to which specific boards are likely to be useful for your design and application. If you are transitioning to RoHS or just need more information about the High TG laminates, just give us a call and we’ll be happy to accommodate you. contact us online right now.