Journal ArticleDOI
Electrically conductive adhesives for surface mount solder replacement
M. Zwolinski,J. Hickman,H. Rubin,Y. Zaks,S. McCarthy,T. Hanlon,P. Arrowsmith,A. Chaudhuri,R. Hermansen,S. Lan,D. Napp +10 more
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TLDR
In this paper, 25 commercially available silver-filled epoxies were evaluated for joint resistance stability on copper and tin/lead surface finishes after 500 h of 85/spl deg/C/85% RH aging.Abstract:
Electrically conductive adhesives offer a lead free, relatively low temperature process for attachment of surface mount components to printed circuit boards (PCB's). The National Center for Manufacturing Sciences (NCMS) Conductive Adhesives project has defined a requirement for an isotropically conductive adhesive (ICA). In this study, 25 commercially available silver-filled epoxies were evaluated for joint resistance stability on copper and tin/lead surface finishes after 500 h of 85/spl deg/C/85% RH aging. Mechanical properties were evaluated through lap shear and impact testing. This testing led to a set of requirements for a surface mount adhesive including a volume resistivity of 1 m/spl Omega/-cm, less than a 20% shift in resistance after aging, and the ability to pass six drops with a plastic leaded chip carrier (PLCC) 44 package from a height of 1.52 m (60 in). Promising candidate adhesives identified in the screening study were evaluated on a circuit board test vehicle with a variety of components. Assembly revealed a narrow processing window when compared to solder. Impact testing demonstrated that current materials have inadequate impact strength for many components and accelerated T/H aging reveals unstable electrical resistance with Sn/Pb finished components. Preliminary data is included on a new adhesive formulation that has been developed to address the shortcomings of currently available ICAs.read more
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Journal ArticleDOI
Recent advances in isotropic conductive adhesives for electronics packaging applications
Irfan Ahmad Mir,Devendra Kumar +1 more
TL;DR: Isotropic conductive adhesives (ICAs) have recently received a lot of focus and attention from the researchers in electronics industry as a potential substitute to lead-bearing solders as mentioned in this paper.
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Reliability of electrically conductive adhesive joints for surface mount applications: a summary of the state of the art
TL;DR: In this article, the authors show that reliable connections with conductive adhesives even under harsh climate conditions are possible with the right choice of adhesive and metallizations of components and boards.
Journal ArticleDOI
Review Of Recent Advances In Electrically Conductive Adhesive Materials And Technologies In Electronic Packaging
TL;DR: In this paper, double and triple-layered Anisotropic Conductive Films (ACF) were developed to meet fine pitch interconnection, low-temperature curing and strong adhesion requirements.
Journal ArticleDOI
Effects of shrinkage on conductivity of isotropic conductive adhesives
Daoqiang Lu,C.P. Wong +1 more
TL;DR: In this paper, the authors investigated the changes in properties, especially in dimension (cure shrinkage), of an isotropic conductive adhesives (ICAs) during cure and to correlate them with the establishment of conductivity.
Journal ArticleDOI
Mechanisms underlying the unstable contact resistance of conductive adhesives
TL;DR: In this article, the authors identify the underlying mechanism that results in the unstable contact resistance phenomenon of the current surface mount conductive adhesives (SMCAs) with non-noble metal finished components.