Developmental research for rapid and automatic appearance inspection technique of electronic and/or print circuit by using optical parallel processing

点击翻译按钮获取中文摘要

New technique for rapid and automatic appearance inspection technique of electronic and/or print circuit by using optical parallel processing has been developed, instead of conventional microscopic image method and digital image processing. Using by the optical analogue image discrimination technique, the inspection and the detection of defects in the speed of light have been realized. The optical difference and/or exclusive or processing between reference and target diffraction pattern of print circuit have been developed by the technique. Multiplexed Matched Spatial Filter (MMSF) has been made, the target diffraction pattern is projected onto the MMSF and the image has been filtered to make the inspection by the MMSF. In the back focal plane of the convex lens that is set on the optical path of objective beam, high intensity defects image can be obtained. To make the MMSF, Photo-conductor Plastic Hologram (PPH) that is processed by solvent vapor has been used. The system composed of … More CCD camera, Spatial Light Modulator (SLM) and/or Programmable Phase Modulator (PPM) has been constructed on an optical rail base. The spatial range of measurement view is approximately 900 square millimeters. In the case of transmissive object, a group of defects those are several tens of micro meters have been discriminated every 30 milliseconds in the view area. The developed technique has much greater performance, compare with conventional digital image processing technique. In the case of reflective object, the rapid and automatic inspection of small defect that is several tens micron meters was difficult without image enhancement. In the defects inspection of the case of gold coating, the defects those are several hundreds of micro meters are inspected rapidly by selecting the wave length of laser. A comparison between optical analogue processing and computer image processing had been done by the authors. As the experimental result, optical analogue processing has big advantages about image resolution and processing speed. In the case of the defects which are part missing, misoriented, wrong parts and misattachment, it is clarified that the optical analogue image discrimination technique is very effective. Less