| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress vibration of interference fringes to accurately detect an internal defect in an inspection object under vibration environment. <P>SOLUTION: A defect inspection device includes: a heating laser 1 which generates impulse waves on the surface of an inspection object M; and a detection laser 2 which detects the impulse waves. The detection laser 2 is branched to a first detection laser 2a and a second detection laser 2b, and different positions of the inspection object M are irradiated with both of the detection lasers 2a, 2b, respectively. In addition, an irradiation position of the first detection laser 2a is irradiated with the heating laser 1. Even when the inspection object M and a measurement device relatively vibrate, since the inspection object M is irradiated with both of the detection lasers 2a, 2b, vibration is canceled, the interference fringes formed by both of the detection lasers 2a, 2b are stabilized without being deviated. Thus, deviation of the interference fringes in accordance with the impulse waves is accurately measured, and an internal defect V in the inspection object M is detected with high sensitivity. <P>COPYRIGHT: (C)2013,JPO&INPIT |
