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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Jul25
Effects of Nitrogen (N2) in SMT Reflow on Various Soldering Defects

Effects of Adding Nitrogen (N2) to SMT Reflow Ovens on Various Soldering Defects

“Oxidation” is a major enemy of solder quality, but oxidation is a natural law of elements striving for stability that cannot be avoided. Using nitrogen (N2) to isolate solder from oxygen (O2) is one of the few effective methods currently available to reduce oxidation of electronic components during high-temperature soldering.

Although nitrogen (N2) is not one of the noble gases of Group 8A, it is classified as an “inert gas” in modern chemistry. Nitrogen is very unreactive in nature, making it unlikely to form compounds with metals. It also makes up 78% of the atmosphere, making it relatively inexpensive to obtain. As a result, nitrogen is often used in SMT reflow ovens to replace oxygen, and in some wave soldering ovens, to reduce oxidation of solder or PCB pads at high temperatures.

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Jul18
Why Do Electronic Products Need Burn-In? What Are Its Pros and Cons? What Is Run-In?

Why Do Electronic Products Need Burn-In? What Are Its Pros and Cons? What Is Run-In?

In the early days, when electronic component design and manufacturing were still developing, the “burn-in” solution was used to screen out defective electronic components and products. This process allowed early-failing products to be identified and eliminated, preventing defective items from reaching customers and causing complaints. Statistical data shows that the lifespan of a batch of electronic products typically forms a “bathtub curve.” This means that there are higher rates of defective components at the beginning and end of their usage, but after a period of use, the defect rate drops to a near-zero stable state, resembling the shape of a bathtub curve.

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