Category Archives: Quality


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

Is that possible both solder joint bridging and open solder joint defect happen at same BGA (Ball Grid Array) or CSP (Chip Scale Package) device? It is hard to see both solder joint bridging and open solder joint defect happen … Continue reading

Jun19
Increase solder paste volume will improve the MLCC capacitor broken?

Recently WorkingBear got complaint from R&D and ask increase the solder paste volume on the MLCC (Multi-Layer Ceramic Capacitor)  component pads to improve the capacitor broken issue. R&D said he had verified that the capacitor’s footprint in the board design … 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 … Continue reading

Jun24
Case study for the mold-in insert screw boss broken

Last time WorkingBear mentioned the potential root causes to bring the screw boss crack after mold-in screw nut insert. Actually we received the complaint from the field then asked EMS and plastic supplier to double check their inventory and found … Continue reading

Jun10
PCB rework: Selective solder mask removal by laser

Did you ever met a trouble need to rework to remove the solder mask from the PCB?  If yes then how you did? We usually remove the solder mask manually  by knife or hand grinding tool. But these kinds of … Continue reading