Aug29
How to Use 2D X-Ray to Identify BGA Issues like Non-Wetting, Cold Solder, and HIP or NWO

How to Use 2D X-Ray to Identify BGA Issues like Non-Wetting, Cold Solder, and HIP or NWO

If you’re an SMT engineer, you’ve probably used an X-Ray inspection machine to check the soldering quality of BGAs. But, after looking at the BGA solder balls repeatedly, they all seem to look the same. So, how can you tell if there’s a non-wetting issue?

Most people use X-Ray inspection machines to check for issues like solder shorts, insufficient solder, or bubbles/voids. However, using X-Ray to determine if BGA solder balls have non-wetting issues is a bit more challenging, especially with a 2D X-Ray machine. But if you’re careful, you can still find clues using 2D X-Ray images to determine if BGA solder balls have voids.

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Aug22
What is ENIG Surface Finished for Circuit Boards? What Are Its Advantages and Disadvantages?

What is ENIG Surface Treatment for Circuit Boards? What Are Its Advantages and Disadvantages?

ENIG (Electroless Nickel Immersion Gold), also known as immersion gold (Au), chemical Ni/Au, or soft gold, is a type of surface finished for printed circuit boards (PCBs). It is widely used in the assembly of mobile phone circuit boards and some BGA package substrates may also use ENIG or NEPIG (Chemical Nickel Palladium Gold).

ENIG is easy to recognize by appearance. If you see a printed circuit board with gold-colored pads (as shown in the image at the beginning of the article), it is likely ENIG. There is another type of “electroplated nickel gold” PCB that also has gold-colored pads, but due to the high cost of gold, it is rarely used unless there is a special need for a thicker gold layer or hard gold.

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Aug15
Causes of Poor Solderability on HASL Finished PCBs (Data Collection and Analysis)

Causes of Poor Solderability on HASL Finished PCBs

Workingbear personally doesn’t recommend using HASL (Hot Air Solder Leveling) surface-finished PCBs in today’s SMT reflow processes, especially for double-sided reflow or fine-pitch components located on 2nd side. The defect rate of soldering with HASL is quite high and hard to overcome.

Most people experienced with SMT processes, when facing issues with SMD components not soldering well, typically first suspect issues with solder paste printing (like improper stencil thickness, aperture, pressure adjustments), solder paste oxidation due to prolonged air exposure, moisture or oxidation on SMD component leads, or incorrect reflow oven temperature profiles.

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Aug08
What Do PCB and PCBA Stand For? What’s the Difference?

What is the difference between PCB and PCBA? This should be an easy concept to understand, but since someone asked Workingbear, let’s explain it a bit. If you find any errors while passing by, please let us know to correct them.

Most people have probably heard of the term PCB. If you follow financial news, YouTube or read related articles, you might have come across this term. However, for those not in the electronics industry, the term PCBA might be less familiar, and sometimes it gets confused with PCB. Even though PCB and PCBA differ by just one letter, there is a significant difference between them in the electronics manufacturing industry.

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Aug01
3D CT X-Ray Non-Destructive 3D Tomography Analysis for PCBA and BGA Failures

3D CT X-Ray Non-Destructive 3D Tomography Analysis for PCBA and BGA Failures

In recent years, the commercial application of 3D CT X-Ray has become increasingly noteworthy. As the technology matures, more companies are investing in its development, making the equipment more affordable, though still not quite at a consumer-friendly price point. Additionally, more laboratories equipped with 3D CT X-Ray are emerging, indicating that more electronics manufacturers are willing to invest in non-destructive testing. Workingbear has encountered at least two labs in Taiwan with 3D CT X-Ray equipment.

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