Patent ID: 7709794
Filing Date: 2010-05-04
Classification: G01N,G01R

Abstract:
1. A method of performing time delay lock-in thermography (LIT) on a sample, the method comprising: moving a field of view (FOV) of an IR camera over the sample, the moving being at a constant velocity; providing a modulation to the sample throughout the moving; capturing IR images using the IR camera throughout the moving, wherein moving the FOV, providing the modulation, and capturing the IR images are synchronized; and filtering the IR images to generate a time delay LIT image, thereby providing defect identification, wherein filtering includes performing two equations: where i=1, 2 . . . , m=1, 2, . . . N x , n=1, 2 . . . N y , f 1 is the frequency of modulation, f 2 is the frame rate, N x and N y are numbers of pixels in one frame in x and y directions.