Method and device for detecting cracks in silicon wafers

摘要

The method involves irradiating a wafer (11) with an infrared light, and exposing a camera (17) by a light transmitted by the wafer, where the camera produces an image of a section of the wafer, which is evaluated in an image processing. The upper surface of the wafer is illuminated with the light and the light reflected at the upper surface is received by a camera (23), where the camera produces another image of the section of the wafer. The crack is detected by combining the two images in the image processing. An independent claim is also included for a device for detecting cracks in a thin wafer plate e.g. in a semiconductor or silicon wafer.