CONTACTLESS TESTING OF ELECTRONIC MATERIALS AND DEVICES USING MICROWAVE RADIATION

摘要

A method and system for probing a volume of material (26) by detecting its local conductivity using microwave radiation of a wavelength selected to excite the carriers of electrical current and induce localized heating in regions of the material. An imaging system detects the size and distribution of the locally heated regions which is then used by a processing system (16) to determine a selected property of the material. The imaging system may be an infrared imaging system (14) which detects infrared radiation emitted from the locally heated regions, a system (13) which deposits a thermally sensitive film (52) onto a surface of the material and detects thermally induced changes in the film caused by the transferred heat, or an optical imaging system (60) having a light source (62) and light detector (64) which detects the locally heated regions based on the local changes in the reflectivity of the surface irradiated with the light source (62).