Shenzhen Xingkexun Electronics Co., Ltd. Contact: Mr. Wu Tel: 0755-81486688
Address: Block D, Yiyuanda Scientific Research Park, Shilong Community, Shiyan Street, Baoan District, Shenzhen, Guangdong.
Treatment of BGA welding failure in common SMT patches
(1) The following describes the bad BGA soldering phenomena in common smt electronic chip processing .
a. Blow holes. Holes or circular pits appear on the surface of the solder ball on the Pcb pad.
b. Cold welding. The surface of the solder joint is dull and not completely welded.
c. Crystal fracture. The surface of the solder joint shows a state of glass cracks.
d. Offset. The BGA solder joint is misaligned with the PCB solder pad.
e. Bridging. Solder flows from pad to pad to form a bridge or short.
f. Splash tin. There are tiny solder balls on the surface of the PCB near or between two solder joints.
(2) Diagnosis and treatment of common BGA welding defects
When the SMT chip is reflowed, gas leaks out of the pores in the BGA solder ball
Use XRay to check the pores inside the raw materials and adjust the temperature curve
Insufficient welding heat, exposed solder joints caused by vibration
Adjust the temperature curve to reduce vibration during cooling
When gold is used as a solder pad, the crystal breaks when gold and tin / lead are melted
Gold solder pads are pre-coated with tin to adjust the temperature curve
Inaccurate patch, conveying vibration
Strengthen the maintenance and maintenance of the placement machine, improve the placement accuracy and reduce the vibration error
Solder paste, solder balls collapse, poor printing
Adjust the temperature curve, reduce the reflow pressure, and improve the printing quality
Bad solder paste quality, heating up too fast
Check the storage time and conditions of the solder paste, select the appropriate solder paste as required, and adjust
Whole temperature curve
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