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Modification of epoxy resins by hydrosilation for electronic encapsulation application
Author(s) -
Ho TzongHann,
Wang ChunShan
Publication year - 1994
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1994.070540102
Subject(s) - epoxy , materials science , composite material , silicone , elastomer , dynamic mechanical analysis , silicone rubber , glass transition , flexural strength , flexural modulus , siloxane , curing (chemistry) , composite epoxy material , polymer
Hydride terminated polydimethyl siloxanes were used to reduce the stress of cresol–form‐aldehyde novolac epoxy resin cured with phenolic novolac resin for electronic encapsulation application. The effects of the structure and molecular weight of the hydride terminated polydimethyl siloxane in reducing the stress of encapsulant were investigated. The mechanical and dynamic viscoelastic properties and morphologies of rubber modified epoxy networks were also studied. A “sea‐island” structure (“islands” of silicone rubber dispersed in the “sea” of an epoxy resin) was observed via SEM. The dispersed silicone rubbers effectively reduce the stress of cured epoxy resins by reducing flexural modulus and the coefficient of thermal expansion, while the glass‐transition temperature was hardly depressed. Electronic devices encapsulated with the dispersed silicone rubber modified epoxy molding compounds have exhibited excellent resistance to the thermal shock cycling test and have resulted in an extended use life for the devices. © 1994 John Wiley & Sons, Inc.