Category Archives: Test/Inspection


Jun26
What is Environmental Stress Screening (ESS)?

Environmental Stress Screening (ESS) is a method used to apply certain environmental and operational stresses—such as power on/off cycles, bias voltage, pressure, thermal cycling, and vibration—to new or repaired products (usually electronics or components). The idea is to expose hidden … Continue reading

Mar21
Electronic Product Burn-In and Run-In: What They Are and Their Pros & Cons

In the early days, when electronic component design and manufacturing were still in their infancy, burn-in (B/I) was widely used to screen out defective products. This process helped eliminate early failures before products reached customers, reducing the risk of complaints. … Continue reading

Jan16
Inspection Methods for BGA Solder Ball Wettability and Soldering Defects

This is a summary post aimed at providing some guidance to newcomers in the electronics assembly field on methods for analyzing the solderability of BGA (Ball Grid Array) solder balls. Workingbear decided to write this after seeing someone ask about … Continue reading

Sep05
Using 2D X-Ray to Diagnose BGA Solder Void Issues

This is an X-ray inspection image of an MCU’s BGA soldering that failed after reflow. The owner mentioned that the BGA package was not functioning, but when pressing on the MCU, it would temporarily work again. Since Workingbear didn’t have … Continue reading

Aug29
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 … Continue reading