Inspection System for Nano-meter Particle on Circuit Board used for New-medium with High Power Laser Diode

在生产过程中粘附到TFT-LCD（薄膜晶体管-液晶显示器）板上的小颗粒（大约大于1 μ m）导致电路图案中的缺陷。在生产过程中，通过使用自动检测系统，对颗粒进行了严格的检测。在本开发中，开发了具有高灵敏度和高速度的自动颗粒检测系统。本系统的理论和实验结果总结如下：1.通过发展半导体激光器倾斜照射平板，检测颗粒倾斜散射的前向光的技术，实现了高灵敏度的检测。当入射角设置为75 °且检测角设置为45 °时，TFT-LCD上的颗粒（直径=1 μ m）的检测信号已经变为常规检查系统的检测信号的8-9倍。通过研制并行检测系统，实现了高速检测。在该系统中，检测单元的宽度已减少到100毫米，结合光路的颗粒检测和自动聚焦的光路。系统采用4个检测单元，独立控制.该系统能够在20秒内检测360 * 460 mm的平板，并在使用4个检测单元检测平板时检测大于1 μ m的小颗粒。

Small particles (approximately larger than 1 mu m) adhered on to TFT-LCD (Thin Film Transistor-Liquid Crystal Display) plates in a production process cause the defects in circuit patterns. The particles have been detected strictly in a production process by employing automatic inspection systems.In this development, an automatic particle detection system with a high sensitivity and a high speed has been developed. The theoretical and experimental results with this system are summarized as follows.1. The high sensitive detection has been realized by developing the technology to illuminate a plate with a laser diode obliquely and to detect the forward light scattered by particles obliquely. The detected signal of a particle (diameter=1 mu m) on TFT-LCD has become 8-9 times as large as a detected signal with conventional inspection system when the incident angle is set to 75ﾟ and the detection angle is set to 45ﾟ.2. The high speed detection has been realized by developing a parallel detection system. In this system, the width of detection unit has been reduced to 100mm by combining an optical path for particle detection with an optical path for automatic focusing. The system uses 4 detection units which are controlled independently.3. This system enables to inspect a plate with the size of 360 * 460mm within 20 seconds and detect small particles lager than 1 mu m when the plate is inspected with 4 detection units.