Optical distance sensor for three-dimensional analysis in quality control testing of semiconductor components - uses variation of optical path length and detection of intensity max. provided by photodetector to provide height profile values
摘要
<p>The sensor uses a confocal optical imaging system for determining the distance and height profile values of a three-dimensional surface. At least one point light source is used to scan the surface, with detection of the image beam via at least one confocal photodetector. The length of the optical path between the detector and the imaging system is periodically varied, with the light intensity max. at the photodetector detected via a peak detector, the corresponding optical path length used for determining the height profile value.</p>
