Method for measuring gap between mask and substrate of display panel

摘要

A method of measuring a gap between a mask and a substrate by providing a mask and a substrate facing each other. The mask includes an array of patterns, and a at least one window disposed between two of the patterns. Each of the patterns corresponds to a display device. The method also includes projecting an incident laser beam onto the substrate through the window of the mask and determining a gap between the mask and the substrate in a middle region of the substrate in response to first and second reflected beams. The first reflected beam is generated by the reflection of the incident laser beam by the mask, and the second reflected beam is generated by the reflection of the incident laser beam by the substrate. Determining the gap between the mask and the substrate in the middle region allows for the correction of any undesirable deflection of the mask.