Online ISSN : 1347-5320
Print ISSN : 1345-9678
ISSN-L : 1345-9678
Development of Polyester-Modified Epoxy Resins for Self-Organization Soldering
Shinji FukumotoKeisuke YoshidaYosuke MizokamiMichiya MatsushimaKozo Fujimoto
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2019 Volume 60 Issue 6 Pages 858-864


Novel underfill resins combining a thermoset epoxy resin with thermoplastic polyester resins have been developed for self-organization soldering. Polyester-modified epoxy resins, which are hybrid resins, exhibited minimal viscosity at the melting point of the Sn–58 mass%Bi solder, with the viscosity dependent on the content and molecular mass of the blended polyester resin. Because the epoxy resin was sufficiently compatible with the polyester resin in the hybrid, the curing reaction of the hybrid resin was similar to that of the epoxy resin. The chemical structure of the polyester resin was retained in the cured hybrid resin, imparting thermoplasticity to the hybrid resins cured with repeated heating. Successful self-organization soldering was achieved using the developed hybrid-resin-based solder paste.

Fig. 7 Formation of solder bumps on LGA substrate via self-organization soldering using resin-based Sn–58 mass%Bi solder pastes. (a) XB1005 thermoset epoxy resin containing 10 mass% of activate agent, (b) HR-A(15%) containing 10 mass% of activate agent, (c) HR-A(15%) containing 30 mass% of activate agent. Images of (d)–(f) are higher magnification images that correspond to images (a)–(c), respectively. The area surrounded by a broken line is a printing area. Fullsize Image
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© 2019 The Japan Institute of Metals and Materials
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