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

fYear

2003

fDate

28-30 Oct. 2003

Firstpage

70

Lastpage

75

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;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronic Packaging Technology Proceedings, 2003. ICEPT 2003. Fifth International Conference on

Conference_Location

Shanghai, China

Print_ISBN

0-7803-8168-8

Type

conf

DOI

10.1109/EPTC.2003.1298695

Filename

1298695