DocumentCode :
2701689
Title :
Conductive adhesive development concept using a bimodal distribution of Ag-particles
Author :
Ye, L.L. ; Lai, Z.H. ; Liu, J. ; Tholen, A.
Author_Institution :
Dept. of Exp. Phys., Chalmers Univ. of Technol., Goteborg, Sweden
fYear :
1999
fDate :
14-17 Mar 1999
Firstpage :
1
Abstract :
Summary form only given. This work aims to develop a conductive adhesive (CA) with a bimodal metal particle distribution to obtain optimum electrical performance without losing mechanical impact strength. Research shows that nanoparticle filled systems can produce higher conductivity at lower particle loading levels. This is attributed to the open nature of agglomerates that make up the conductive network in nanoparticle filled polymers. However, it is difficult to control rheology when applying this type of CA in the stencil printing process. The objective of this work is to introduce nanoparticles in micro-size metal particles to form a bimodal distribution in the polymer matrix. Previous examinations of Ag-filled particles reveal that micro-sized particle fillers appear as full density Ag flakes, while nanoparticle fillers appear as highly porous agglomerates, similar to open-cell foams. Little study has been carried out on the cross-sectional area of a particle-particle contact in CA, but some initial results indicate that the real contact area is several orders of magnitude smaller than that estimated from simple geometric considerations. In this study, TEM is used as the main measurement method to analyse the nanoparticle distribution. The volume nanoparticle percentage in the micro-size particle varies from 2.7 wt% to 13.8 wt%, and the total metal content is in the range of 60-80 wt%. The change of contact area and contact behaviour with various volume ratios of nano-size and micro-size particles was also studied. Electrical resistivity and mechanical strength were measured and compared for different filler loading levels
Keywords :
adhesives; conducting polymers; electrical resistivity; filled polymers; impact strength; packaging; rheology; silver; transmission electron microscopy; Ag; Ag-filled particles; Ag-particles; TEM; agglomerates; bimodal distribution; bimodal metal particle distribution; bimodal particle distribution; conductive adhesive; conductive network; conductivity; contact area; electrical resistivity; filler loading; full density Ag flakes; mechanical evaluation; mechanical impact strength; metal content; micro-size metal particles; micro-size particles; micro-sized particle fillers; nano-size particles; nanoparticle distribution; nanoparticle filled polymers; nanoparticle filled systems; nanoparticle fillers; nanoparticles; open-cell foams; optimum electrical performance; particle loading levels; particle-particle contact area; polymer matrix; porous agglomerates; rheology; stencil printing process; Conductive adhesives; Conductivity; Contacts; Electric resistance; Electric variables measurement; Mechanical variables measurement; Nanoparticles; Polymers; Printing; Rheology;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Advanced Packaging Materials: Processes, Properties and Interfaces, 1999. Proceedings. International Symposium on
Conference_Location :
Braselton, GA
Print_ISBN :
0-930815-56-4
Type :
conf
DOI :
10.1109/ISAPM.1999.757277
Filename :
757277
Link To Document :
بازگشت