| In microelectronics packaging, reliability of the metal/polymer interfaces is an important issue because adhesion strength between dissimilar materials are often inherently poor, and residual stresses arising from thermal mismatches or pressures exerted by vaporized moisture often lead to delaminations of interfaces. Modification of polymer surfaces by the rf plasma and oxidation treatments of metal surfaces before joining are commonly used methods to enhance the adhesion strength of the interface, and therefore it is important to measure and analyze the adhesion strength. In this study: 1) The practical adhesion strength of Cu/polyimide and Cu-based leadframe/EMC interfaces were measured using the peel, pull-out, and fracture mechanics tests, and the effect of rf plasma pretreatment and oxidation pretreatment of leadframe were investigated. 2) The correlations among peel strength, pull out strength, and interfacial fracture toughness were made, and the interfacial fracture energies were derived from the practical adhesion strengths using X-ray measurements and theoretical analyses. 3) The thermodynamic analysis of interface fracture, proposed by Rice^1), was applied to the metal/polymer interfaces. |
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