Design and development of a new machine vision wire bonding inspection system

摘要

In this paper, we developed a fast and robust machine vision system for wire bonding inspection. The defects caused by a bonding wire being broken, lost, shifted, shorted, or sagged in an integrated circuit (IC) chip can be inspected automatically. A new lighting environment was devised which will highlight the slope of the bonding wire and suppress the background from being extracted. First, a set of machine vision algorithms were designed to filter out the defects of broken wire, lost wire, shifted wire, and shorted-out wire. Second, the 3-D type defect of sagged wire can be detected by inspecting the change of the bonding wire slope, derived from a single 2-D image. Some illustrations are given to show the efficiency and effectiveness of the proposed novel wire bonding vision inspection system.