Title :
Solder joints design attribute to no solder bridge for fine pitch device
Author :
Yu, Li Ming ; Qing, Wang Chun
Author_Institution :
State Key Lab. of Adv. Welding Production Technol., Harbin Inst. of Technol., China
Abstract :
Solder bridge is a serious defect of solder joints in ultra fine pitch devices assemblies, such as QFP256 (QFP: Quad Flat Packaging). It has been known that generation of the solder bridge is closely related to formation process of the solder joints. A three-dimensional model to simulate the formation process of the solder joints bridge of QFP256 is formed and numerically simulated to predict formation shape using Surface Evolver program in this paper. Based on these results, solder bridging mechanism and factors influencing the solder bridge are investigated, involves solder volume, wetting angle, pad size, lead position on the pad. The results show that there is a critical solder volume V/sub c/for the solder joints to avoid solder bridging, which can be used to evaluate anti-bridging ability of the solder joints.
Keywords :
fine-pitch technology; finite element analysis; reflow soldering; surface mount technology; wetting; QFP256; Surface Evolver program; advanced surface mount technology; lead position; no solder bridge; pad size; solder joints design attribute; solder volume; three-dimensional model; ultrafine pitch devices; wetting angle; Assembly; Bridges; Electronics packaging; Equations; Lead; Predictive models; Shape; Soldering; Surface tension; Surface-mount technology;
Conference_Titel :
Electronic Packaging Technology Proceedings, 2003. ICEPT 2003. Fifth International Conference on
Conference_Location :
Shanghai, China
Print_ISBN :
0-7803-8168-8
DOI :
10.1109/EPTC.2003.1298695
