DocumentCode :
1391050
Title :
Isotropic conductive adhesives filled with low-melting-point alloy fillers
Author :
Lu, Daoqiang ; Wong, C.P.
Author_Institution :
Sch. of Mater. Sci. & Eng., Georgia Inst. of Technol., Atlanta, GA, USA
Volume :
23
Issue :
3
fYear :
2000
fDate :
7/1/2000 12:00:00 AM
Firstpage :
185
Lastpage :
190
Abstract :
Conventional isotropic conductive adhesives (ICAs) are composed of a polymeric matrix and silver (Ag) flakes. As an alternative to lead-bearing solder, ICAs offer a number of benefits, but limitations do exist for ICA technology. ICAs filled with silver flakes generally show higher initial contact resistance, unstable contact resistance, and inferior impact strength. In this study, a new class of isotropic conductive adhesives was developed by using two different fillers, silver flakes and a low-melting-point-alloy filler, into the ICA formulations. After curing, the metallurgical connections between silver particles, and between silver particles and nickel (Ni) substrate were observed using scanning electron microscopy (SEM). Electrical properties including bulk resistance, initial contact resistance, and contact resistance shifts of the ICA were investigated and compared to those of a commercial ICA, an in-house ICA filled with only the silver flake, and a eutectic Sn/Pb solder. It was found that: (1) the low-melting-point alloy filler could wet the silver flakes and nickel substrate to form metallurgical connections, (2) this ICA had much lower bulk resistance than the commercial ICA and the in-house ICA filled with only the silver flake, and (3) this ICA showed especially low initial contact resistance and more stable contact resistance during aging on nickel metal compared to the ICA filled only with silver flakes
Keywords :
adhesives; ageing; conducting polymers; contact resistance; filled polymers; packaging; aging; contact resistance; impact strength; isotropic conductive adhesives; low-melting-point alloy fillers; metallurgical connections; scanning electron microscopy; Conductive adhesives; Contact resistance; Curing; Electric resistance; Independent component analysis; Lead; Nickel; Polymers; Scanning electron microscopy; Silver;
fLanguage :
English
Journal_Title :
Electronics Packaging Manufacturing, IEEE Transactions on
Publisher :
ieee
ISSN :
1521-334X
Type :
jour
DOI :
10.1109/6104.873246
Filename :
873246
Link To Document :
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