Reliability Improvement of Sub 100 µm Lead Free FC Solder Joint by a Pre-bonding Technique

Conference: Smart Systems Integration 2008 - 2nd European Conference & Exhibition on Integration Issues of Miniaturized Systems - MOMS, MOEMS, ICS and Electronic Components
04/09/2008 - 04/10/2008 at Barcelona, Spain

Proceedings: Smart Systems Integration 2008

Pages: 3Language: englishTyp: PDF

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Luo, Le; Lin, Xiaoqin (Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China)

A pre-bonding technology was developed to improve the reliability of the high density lead-free flip-chip solder joint on PCB. The pre-bonding process was carried out by a moderate force stressed vertically by the bonding tool just after pick-and-place process. The standoff height of FCOB assemblies increased after the reflow process. By this way, the flip chip solder bumps can achieve 100% interconnection with low-cost PCBs and form strongly bonding, even with a larger mismatch between solder bumps and the copper pad. The flip chip bonding parameters of the process were studied and optimized. The effects on the reliability of FCOB were discussed.