A Technique to Mount Narrow-Pitch Micro Solder Balls

Micro solder balls are used in flip-chip mounting to form bumps on a BGA (Ball Grid Array) substrate. As electronic devices become more compact, solder balls have become smaller in size and narrower in pitch. We examined to utilize the gravure offset printing method, which applies the micro wire printing technology to mount 30 μm micro solder balls in a narrow pitch.