عنوان مقاله [English]
The progress in scientific and technical products and increasing needs for advanced electrical and electronic devices have motivated researchers to investigate new ideas in this field. One of the main challenges in this way is the connection between microchips and other parts of electrical boards. Lead-based alloys, especially tin-lead solders are the conventional materials which have destructive effects on living organisms and the environment. Electrical conductive adhesives, used as replacement for lead-based solders, are composites comprised of a polymer matrix as adhesive material and conductive fillers for conduction of electricity. In this research conductive adhesives were prepared using diglycidyl ether of bisphenol A epoxy resin as the polymer matrix and various amounts of silver-coated copper powder as conductive filler. The copper powder was coated with silver using electroless plating. The structural properties of the filler was characterized by inductivity coupled plasma analysis. The morphology of the samples was investigated by scanning electron microscopy. The conductive properties, shear strength and thermal stability of adhesives were also evaluated. The conductive adhesive containing 70 percent by weight of silver-coated copper powder showed optimum properties. For this sample an electrical resistivity of 2.8×10-2 Ω.cm and a shear strength of 10.77 MPa were obtained. In addition, the weight loss during thermogravimetric reduction was 23.69% for the optimum sample, while it was 88.71% for the sample with no filler, indicating an improvement in thermal stability due to adding filler.
1.Dou S., Qi J., Guo X., and Yu C., Preparation and Adhesive Performance of Electrical Conductive Epoxy-Acrylate Resin Containing Silver-Plated Graphene, J. Adhes. Sci. Technol., 28, 1556-1567, 2014.
2.Jagt J.C., Reliability of Electrically Conductive Adhesive Joints for Surface Mount Applications: A Summary of the State of the Art, IEEE Transac. Compon. Pack. Manufact. Technology, Part A, 21, 215-225, 1998.
3.Li Y. and Wong C., Recent Advances of Conductive Adhesives as a Lead-free Alternative in Electronic Packaging: Materials, Processing, Reliability and Applications, Mater. Sci. Eng. R: Reports, 51, 1-35, 2006.
4.Chien I.Y. and Nguyen M.N., Low Stress Polymer Die Attach Adhesive for Plastic Packages, Proceeding of 44th Electronic Components and Technology Conference, 580-584, 1994.
5.Galloway D.P., Grosse M., Nguyen M.N., and Burkhart A., Reliability of Novel Die Attach Adhesive for Snap Curing, Proceeding of Electronics Manufacturing Technology Symposium, 17th IEEE/CPMT International, 141-147, 1995.
6.Gonzales J.I.J. and Mena M.G., Moisture and Thermal Degradation of Cyanate-Ester-Based Die Attach Material, Proceeding of 47th Electronic Components and Technology Conference, 525-535, 1997.
7.Lutz M. and Cole R., High Performance Electrically Conductive Silicone Adhesives, Microelectron. Int., 7, 27-30, 1990.
8.Pujol J., Prud’homme C., Quenneson M., and Cassat R., Electroconductive Adhesives: Comparison of Three Different Polymer Matrices. Epoxy, Polyimide and Silicone, J. Adhes., 27, 213-229, 1989.
9.Mikrajuddin A., Shi F., Chungpaiboonpatana S., Okuyama K., Davidson C., and Adams J., Onset of Electrical Conduction in Isotropic Conductive Adhesives: A General Theory, Mater. Sci. Semiconduct. Proc., 2, 309-319, 1999.
10.Lovinger A.J., Development of Electrical Conduction in Silver-Filled Epoxy Adhesives, J. Adhes., 10, 1-15, 1979.
11.Zhang R., Agar J.C., and Wong C., Recent Advances on Electrically Conductive Adhesives, Proceeding of 12th Electronics Packaging Technology Conference (EPTC), 696-704, 2010.
12.Lumpp J., Li J.K., Andrews R., and Jacques D., Aspect Ratio and Loading Effects of Multiwall Carbon Nanotubes in Epoxy for Electrically Conductive Adhesives, J. Adhes. Sci. Technol., 22, 1659-1671, 2008.
13.Tao Y., Yang Z., Lu X., Tao G., Xia Y., and Wu H., Influence of Filler Morphology on Percolation Threshold of Isotropical Conductive Adhesives (ICA), Sci. China Technol. Sci., 55, 28-33, 2012.
14.Wu H., Wu X., Ge M., Zhang G., Wang Y., and Jiang J., Effect Analysis of Filler Sizes on Percolation Threshold of Isotropical Conductive Adhesives, Compos. Sci.
Technol., 67, 1116-1120, 2007.
15.Ma H., Qiu H., and Qi S., Electrically Conductive Adhesives Based on Acrylate Resin Filled with Silver-Plated Graphite Nanosheets and Carbon Nanotubes, J. Adhes. Sci. Technol., 29, 2233-2244, 2015.
16.Prolongo S.G., Moriche R., Jiménez-Suárez A., Sánchez M., and Ureña A., Epoxy Adhesives Modified with Graphene for Thermal Interface Materials, J. Adhes., 90, 835-847, 2014.
17.Liu Q., Zhou X., Fan X., Zhu C., Yao X., and Liu Z., Mechanical and Thermal Properties of Epoxy Resin Nanocomposites Reinforced with Graphene Oxide, Polym. Plast. Technol. Eng., 51, 251-256, 2012.
18.Djokic S., Dubois M., and Lepard R.H., Process for the Production of Silver Coated Particles, US Pat. 5945158A, 1999.
19.Zandiatashbar A., Picu R., and Koratkar N., Mechanical Behavior of Epoxy-Graphene Platelets Nanocomposites, J. Eng. Mater. Technol., 134, 031011-031016, 2012.