Adhesive strength of flip chip packages

The mechanical behavior and failure mechanisms of non-conductive adhesive (NCA) joints exposed to accelerated testing environments have been investigated. The study reveals that moisture preconditioning induces a rapid and drastic decrease in the mechanical strength and modulus of NCA joints. Recovery experiments indicate that the loss in modulus was reversible upon re-drying, but nonetheless more irreversible damage did occur at NCA joints due to hydrolysis. A hydrolytic degradation mechanism at the NCA/polyimide interface is proposed.