Archive for the ‘PCB News’ Category

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

Tuesday, 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.

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

Wednesday, 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

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

Thursday, 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.

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Interesting color matching – Silkscreen and Solder mask

Tuesday, 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.

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The Advantages of Surface Mount Technology of a printed circuit board

Friday, 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.

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Do the vias can be filled for ceramic PCB?

Friday, November 13th, 2020

As everyone knows for FR4 PCB, people like the vias to be tented or filled for some special applications.
Ceramic PCB is more and more popular because of the thermal conductivity is very high and very good for heat dissipation. Most of customers are going to make the PCB with ceramic material, includes Al2O3, AlN, BeO or Si3N4, etc.
So do the vias can be filled for ceramic PCB becomes the frequently asked questions (FAQ).
The answer is YES.
So what’s the material can be filled in vias for DBC/DPC alumina PCB/ Aluminium Nitride PCB?

The material can be solder mask, Dow Corning 1-4173 and copper/Cu.
Normally, customers want the vias/holes to be filled with copper.
Because copper can fill the vias very well and it is easier to do and it looks very good. Please see below photo.
The left one with filling with copper, the right one without filling copper

Why you need to fill the vias with copper?
1.Becuase if let the vias open, they will allow solder to flow through to opposite side of PCB during reflow, this causes bridging under components.
Filling the open vias/holes with copper can prevent from the solder pates into the vias.
2.If you need to pull vacuum around them and a hole would compromise that, so need to fill the vias.
There are also other purposes for filling the vias, if you need such ceramic board with filling the vias, please contact Coco in Best Technology sales@bestpcbs.com

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What are the commonly used aluminum base materials? What’s the difference?

Wednesday, November 11th, 2020

Best Technology has more than 14 year experience for producing Metal core PCB, we have our own raw materials factory for MCPCB and we fabricate MCPCB in Shenzhen, so that customer various special requirements can be meet here.

Compared to copper and stainless steel, aluminum is the most economic option considering thermal conductivity, rigidness, and cost. And many of these aluminum alloys base have been divided into classes, the commonly used on MCPCB are AL1060, AL3003, AL5052 and AL6061.

Do you know the differences between these substrates? This blog will give a brief introduction for you.

1060 alloys
AL1060 are commercially pure, unalloyed aluminum, it’s soft, ductile, workability and exceptional corrosion resistance, making it suitable for hard-forming applications. It can be welded with any method, but it cannot be heat-treated. Its cost is the lowest of the four types.

3003 alloys
AL3003 use silicon, copper, and magnesium as the main alloying elements, oftentimes with supplemental nickel and beryllium. They are heat treatable, have high strength, good resistance to cracking and wear, and have good machinability.

Mechanical PropertiesMetricEnglish
Ultimate Tensile Strength200 MPa29000 psi
Tensile Yield Strength186MPac
Shear Strength 110 MPa16000 psi
Modulus of Elasticity68.9GPa10000 ksi
Shear Modulus25 GPa3630 ksi

5052 alloys
AL5052 use magnesium as their primary alloying element and are not heat-treatable, but it’s the highest strength alloy of the more non-heat-treatable grades. Its resistance to fatigue is better than most grades of aluminum and have a great surface aesthetic when anodized.
In our company, if not special request or notes, the default material we use is AL5052 after considering all the performance and cost.

Mechanical PropertiesMetricEnglish
Ultimate Tensile Strength228 MPa33000 psipsi
Tensile Yield Strength193 MPa28000psi
Shear Strength138 MPa20000 psi
Modulus of Elasticity70.3GPa10200 ksi
GPaShear Modulus 25.9 GPa25.9 760 ksi


6061 alloys

Mechanical PropertiesMetricEnglish
Ultimate Tensile Strength310 MPa45000 psi
Tensile Yield Strength276 MPa40000 psi
Fatigue Strength207MPa30000 psi
Shear Strength96.5MPa14000 ksi
Modulus of Elasticity68.9 GPa10000 ksi
Shear Modulus26 GPa770 ksi

AL6061 implement magnesium with silicon as their principal alloying elements. Their strength is improved with heat treatment. AL6061 is one of the most widely used aluminum alloys, it has high strength and superior corrosion resistance. Its weld-ability and formability make it suitable for many general-purpose applications.

Cost Comparison: AL1060 < AL3003 < AL5052 < AL6061

If you have other questions about MCPCB, welcome to contact Tammy (Email:sales@bestpcbs.com), she will prove you professional suggestions and solutions.

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ENIG surface finish of FR4 Printed wiring board

Wednesday, November 4th, 2020

Continued to my last blog, do you know why we want to talk more for Gold surface finish of rigid Boards? I would like to take this chance to share more information for the capability from Best Technology.

Electroless nickel immersion gold (ENIG) is a type of surface plating used for printed circuit boards. It consists of an electroless nickel plating covered with a thin layer of immersion gold, which it can protects the nickel from oxidation. It is also used for welding and applied to contacts (such as keys, gold fingers on memory strips, etc
See attached complexity design for ENIG FR4 printed circuit board.

ENIG has several advantages over more conventional (and cheaper) surface plating such as HASL (solder), including excellent surface planarity (particularly helpful for PCBs with large BGA packages), good oxidation resistance, and usability for untreated contact surfaces such as membrane switches and other contact points. See the complex circuit boards design photo.

ENIG also does not wet as evenly or easily as HASL. In addition, ENIG is a costlier finish, but offers the best characteristics for printed circuit boards. The process requires the most steps compared to other common finishing types.
The thickness of Gold Best Technology conforms to IPC Standard IPC-6013.
Let us see the different for gold finish.

Gold-ENIG
The most important factor the gold serves as barrier and protectant to the nickel.
Advantages of ENIG

Immersion finish = excellent flatness
Good for fine pitch / BGA / smaller components from Samtec/Hirose/Molex
Wire bondable
Good heat dissipation
Long shelf Life (12 months in vacuum pack)

Disadvantages of ENIG
Expensive finish
Black Pad/Black Nickel concerns on BGA
Damage from ET (electronics test)
Signal Loss (RF)
Complicated Process

Gold-Hard Gold

Advantages of ENIG
Hard, Durable Surface
No Pb
Long shelf life

Disadvantages of ENIG
Very Expensive
Extra Processing/ Labor Intensive
Use of more solder Resist/Tape
Plating/ Bus Bars
Demarcation(delamination)
Difficulty with other surface finishes.

As an rich experience PCB manufacturer since 2006, Best Technology always improve its Rigid Circuit boards capability to meet customer requirements, If you have any question about the printed circuit boards (PCBs). Warmly welcome to send mail or call Best Tech.

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What is PP (Prepreg) and CORE in a PCB?

Friday, October 30th, 2020

We all know that both Prepreg (PP) and CORE are important parts for the printed circuits board. And they are also very common on the PCB structure.

But what exactly they are? What’s the difference of a PP and Core for a FR4 PCB?

Prepreg, referred to as PP, it is a sheet material impregnated with resin and cured to an intermediate level (B-stage), known an insulating material for the PCB board.
As a prepreg material while the PCB production process, before lamination, it is mainly used as an adhesive material and insulating material for the inner conductive pattern of a multilayer PCB.

After the Prepreg is laminated, the semi-cured epoxy resin is squeezed away, starts to flow and solidify, bonding the multilayer circuit boards together, and forming a reliable insulator.

PP, it is placed between the two copper layers to isolate and make the two copper layers adhere. Below picture for you to see where the PP is on a PCB stack up.

And CORE, it is totally different as the Prepreg.

Core is with certain hardness and specified thickness, and with copper foil in both sides.
It is the basic material for making printed circuits boards, and the multilayer PCB board is actually made by pressing Core and Prepreg.
Sometimes, when people are talking about the Copper Clad Laminate (CCL), they also refer to the CORE.

And here is the major difference for the PP and Core:

  1. Prepreg is stayed with a semi-solid material in a PCB, similar to cardboard. But core is different, core is hard, similar to copper;
  2. Prepreg is similar to adhesive + insulator; while Core is the basic material of PCB, they have completely different functions;
  3. PCB Prepreg can curl, but PCB Core cannot bend;
  4. Prepreg is non-conductive, and the core has a copper layer on both sides, which is the conductive medium for a PCB board.

As an PCB manufacturer with more than 15 years experiences in China, Best Technology insists on using the best Copper Clad Laminate ( CCL) materials to make the PCB, no matter Prepreg or CORE, we will select the best FR4 materials for the PCB manufacturing, to make sure all the PCB boards we supplied to customers are with qualified materials and to be your best PCB suppliers in China.

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What’s the Countersink and counter bore on a PCB drawing?

Wednesday, September 30th, 2020

Firstly, do you know what’s a countersink and counter bore?

By definition, a countersink is a stepped hole, which can allow the fasten parts head to sink fully to the parts.

With counter sink on your design, the tapered head of a screw can sit flush with the top of the laminate, commonly countersink is used to install bolts or other connecting parts.

Below is the example for the hole drawing and picture for a countersink:

Picture: counterbore holes attributes

To drill your countersunk holes accurately in our PCB fabrication plant, the following information is need to be defined when you supply the PCB drawing for us to make the PCB:

  • Which side of the board is the countersink hole should be drilled, on top or bottom?
  • Is the sink and shaft to be through plated or non-plated?
  • Taper angle or countersink angle. 82°, 90°,120° etc.
  • Countersink diameter of top
  • Countersink diameter of bottom (body)
  • Depth of the countersink is to be drilledthe height of the screw to determine the countersink depth.

By comparison, a counterbore makes a flat-bottomed hole and its sides are drilled straight down. This is usually used when a fastener such as a bolt or cap head screw is required to sit flush with or below the level of a surface.

Below is the drawing and picture for a countersink.

Same as the countersink, the counterbore holes attributes drawing is needed to supply with your PCB drawing when fabricate the counterbored holes. But for counterbore on PCB, because the sides of the hole are always parallel, there is no need to specify the angle.

With below drawing, believe it will be more helpful for you to understand the difference for a counter sink hole and counterbore on the printed circuits board.

If need to have any question regarding the counter sunk or counter board on a PCB drawing, please contact us feel free.

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