A robust method of IC seating inspection in burn-in sockets using Hough transform

In IC chips manufacturing process, burn-in test is one of the most important testing methods. They are subjected to a temperature and voltage load in a burn-in machine to detect defective chips. A serious problem may occur if IC chips are not placed correctly in burn-in sockets in the machine. To ensure correct IC chips seating, there is an inspecting method to investigate the relationship between two straight lines on the surface projected by a line laser beam, one is on the IC chip and another one is on the socket. We propose a robust image analysis method even when the laser beam is diffusely reflected. The proposed method detects laser line using the Hough transform to achieve fast and stable seating inspection. We have conducted experiments using images of IC chips used in actual tests and evaluated our method.