Patent ID: 6610991
Filing Date: 2003-08-26
Classification: G01B,H01L,H05K

Abstract:
An optical system for sensing a height of a feature on an object, the system comprising:a lens system for viewing the feature; a detector; a first optical path having a first aperture viewing the feature from a first angle, so as to form a first partial image of the feature on a first section of the detector, the first partial image representative of a portion of the feature; a second optical path having a second aperture aligned to an optical element so as to view the feature from a second angle and to re-direct light passing through the second aperture and the optical element onto a second section of the detector, thereby forming a second partial image representative of a portion of the feature thereon, the first angle different from the second angle; a motion control system for providing a relative motion between the detector and the feature; control electronics for collecting image portions from the detector; and video processing circuitry for assembling the image portions from the first and the second optical paths into a first and a second assembled image, respectively, the circuitry providing the height of the feature as a function of the first and the second assembled images.