Friction Technique for Optimum Thermocompression Bonds

The successful application of thermocompression lead bonding to semiconductor or thin-film electronic devices depends on the establishment of the associated parameters. The quality of a thermocompression bond is primarily related to the process temperature and bonding force. A technique using the coefficient of friction is presented that both reduces the time necessary for determining optimum parameter values and increases the accuracy of the results. Modem theories of the friction process are used to develop mathematical expressions for shear and tensile bond strengths in terms of friction measurements. A further application of the parameter determination technique concerns the measurement of surface contamination that may affect thermocompression bonding.