Study On Machine Vision Inspection And Automatic Orientation Control Technology Of Full-Automatic BGA Ball Mounting

Semiconductor field is one of the most important application fields of machine vision technology. As the mainstream technology currently of semiconductor encapsu- lation, Ball Grid Array (BGA) certainly needs the support of machine vision technology. This paper adopts machine vision technology to solve exact inspection and accuracy orientation problems of BGA ball mounting. The following is the main content of this paper.1. Studyed BGA encapsulation technics and the mechanical structure of BGA ball mounting. Obtained the characteristic of BGA encapsulation and the difficulties on technique during the development of BGA ball mounting. Based on the above-mentioned knowledge, put forward the requirement that the machine vision system should satisfied.2. Started with the encapsulation technics of BGA ball mounting, analyzed the indispensability and essentiality to adopt machine vision technology in BGA ball mounting. Introduced the general evolution situation of machine vision. Designed the hardware integration scheme and software flow.3. Studyed the theoretics and methods of digital image processing, which included image saveing and reading, pre-processing, character distill, templet matching and some match arithmetic to improve matching efficiency etc.. Achieved image capture control, inmage pre-processing, defect inspection and movement control in VC.4. Aim at the movement control reqirement of BGA ball mounting, improved the movement control performance of BGA vision system. Adopted movement control-card with DSP, closed loop feedback to increase position precision while S accelerate curve to reduce concussion.