A new method of thermal healing treatment to study the recovery of the bonding energy of a previously opened bonded surface between oxidized silicon wafers was presented in this report. The wafers, partially deboned by blade insertion, were subjected to various annealing temperatures for thermal healing purposes. The annealed wafer pairs were re-examined by a second cycle of blade-insertion testing. During each cycle of blade insertion, the length of the propagated crack due to the inserting blade was continuously monitored by using an infrared light and a charge-coupled device camera. Comparing the crack lengths in front of the inserted blades from those IR transmission images, the healing quality of the annealed wafers is observed. It is found that a 1273 K healing treatment provides good bonding quality. (c) 2006 The Electrochemical Society.