FILM THICKNESS MEASURING METHOD AND DEVICE OF TRANSPARENT FILM

摘要

PROBLEM TO BE SOLVED: To provide a method and a device for measuring the film thickness of a transparent film. SOLUTION: An irradiated beam 4 is passed through an objective lens 5 and guided to an object 1 having the transparent film 2. A structured focusing auxiliary member 9 is arranged in the irradiated beam 4, and a camera 13 is arranged in an image beam 12, and each of them is arranged on a conjugate position relative to a focusing surface 8 of the objective lens 5. The focusing surface 8 of the objective lens 5 is moved gradually through the object 1. Camera images are recorded at respective positions, and focus scores thereof are determined, and the image of the focusing auxiliary member 9 is used as a sharpness display device. The position having a maximal focus score is assigned to the position of an interface. The thickness of the transparent film 2 is calculated from the difference between each position of the interfaces.