Thermally induced stresses in semiconductor laser packaging

The thermally induced stresses in the laser welding technique for semiconductor laser packaging are calculated by using the finite-element method (FEM). Results obtained from stainless-to-Kovar joints indicate that the Kovar with an Au coating shows a higher stress than that without a coating. There is satisfactory agreement between experimental results and the finite-element predictions that the higher stresses induced by Au in Kovar during the welding process are a possible cause for surface cracks.