Category Archives: Quality


Apr11
Why Do BGA Solder Balls Keep Cracking (13)? Usage Environment is the Biggest Challenge of Stress Sources

Congratulations! This article is the last one in this series. You won’t have to listen to WorkingBear ramble on about this boring topic again in the future! Usage Environment is the Biggest Challenge of Stress Sources After discussing the precautions … Continue reading →

Jul22
What purpose of alloy metal of Cu, Ag, Zn, Sb, Bi added to solder paste?

Tin (Sn) based solder is still the best material for PCB (Printed Circuit Board) assembly in the modern industry today. The only difference is the lead (Pb) free from the solder base due to environmental concerns. The melting point of … Continue reading →

Dec05
Both solder joint bridging and open solder joint happen at same BGA?

Is that possible for both solder joint bridging and open solder joint defect occur in the same BGA (Ball Grid Array) or CSP (Chip Scale Package) device? It is rare to observe both solder joint bridging and open solder joint … Continue reading →

Jun19
Will Increasing Solder Paste Volume Help Prevent MLCC Cracking?

Figure: Will Increasing Solder Paste Volume Help Prevent MLCC Cracking? Recently, Workingbear received a complaint from R&D asking us to increase the solder paste volume on the MLCC (Multilayer Ceramic Capacitor) component pads to improve a capacitor cracking issue. R&D … Continue reading →

May03
Trouble Shooting Guide for Plastic Injection

Trouble Suggested Remedies (Solutions) DIMENSIONAL PROBLEMS Shot-to-shot dimensional variations Increase injection pressure Maintain uniform pad (cushion) Repair leaking back flow value if pad cannot be maintained Increase screw forward time Maintain uniform cycle Eliminate un-melted particles (see below) Use larger … Continue reading →