Abstract
In this research, packaging structures in which chip parts were bonded to the ceramics substrate of Alumina (Al_2O_3) or nitride aluminum (AlN) with electro-conductive adhesive etc. through a thick film conducting electricity, was studied. For the structures, the bonding remaining strength, considered the residual stress caused in a bonding process based on fracture mechanics, was evaluated, and the influences of both the ceramics substrate and the thick film conductor's thermo-physical property on the strength were examined. Moreover, to examine the decrease behavior of the bonding residual strength by heat cycle loads in-service, thermal cycle tests, the verification tests of a peeling strength, and the simulation analyses of those tests were done, and the peeling fracture strength and the fracture life were predicted. As a result, the mechanism of trouble generated in-service is clarified from the viewpoint of fracture mechanics, the validity of remedies is confirmed, and the present research is useful for the new development of the product.
