Non-contact metrology inspection system for precision micro products

Non-contact metrology systems are gaining popularity as the micro products industries are establishing to meet high level of demand. Precision micro products are used in the fields of electronics, computer, medical and aerospace systems. So far, the production technologies are well advancing in the form of lithography and non-lithography based techniques. But, the dimensional inspection at micro-meso scale is not possible with conventional touch based systems. Micro-meso (10μm to few mm) scale artifact inspection needs non-conventional methods as compared to the well-established contact methods for normal large size manufacturing. The inspection of these parts is a challenge for the micro-manufacturing industry. Non-contact metrology inspection has turned out as a solution to this problem. Non-contact vision systems based technique has accuracy constraints. Computer vision system is used to model the artifact data through digital image. Edge detection technique is used to find the edges in the image to extract the required information. Many pixel and sub-pixel edge detection techniques are used for this purpose. Sub pixel edge detection through interpolation method is explored and implemented on various features of different samples. The behavior of the pixel and sub-pixel edge detection techniques is tested for different mega pixels. Using sub-pixel techniques, the system error is reduced by taking into account inside pixel information.