VARIATIONAL PRINCIPLE OF THIN-FILM ADHESION

The interfacial fracture energy between a thin polyimide film and a rigid Si substrate was measured via the blister test. A dynamic debonding mechanism was used instead of a static debonding mechanism. A nonlinear analytical method was developed based on local energy balance for the dynamic debonding process of the blister test. The main advantages of this method are that (1) the dissipated energies which accompany the debonding processes can be measured and (2) the mechanical properties of thin films do not enter into the calculation of adhesion strength. A minimum value for adhesion energy can be obtained which compares favorably with estimated values of adhesion.