Development of First Production Flaw Detecting System for On-Demand Repair of Large-Scale Circuit

摘要

To realize an efficient high-mix low-volume production, improving the yield rate by reducing production flaws is an important technique. Manufacturing touch panel displays with large-scale wiring boards is a typical example of the high-mix low-volume production. The National Institute of Advanced Industrial Science and Technology (AIST) has proposed a laser assisted ink-jet printing (LIJ) technology, which can repair the flaws of circuits by a silver nanoparticle ink. To establish an in-process repairing system for a touch panel display, a first production flaw detecting system is necessary in combination with LIJ technology. Therefore, the aim of this study is to develop a new first production flaw detecting system, which detects flaws in a large-scale circuit quickly. In this report, we have covered the basic concept of the proposed system, and the details of some preliminary experiments conducted using the developed measurement system. The performance requirements for the first production flaw detecting system are discussed. The basic concept of the detecting system and optical set-up was finalized. A preliminary first production flaw detecting system with galvano-scanner and multi-photodiode array was developed to confirm its ability to detect flaws and pattern profile. Some basic experiments were conducted to check the performance of this system. A flaw was intentionally created by making a scratch on a circuit pattern; the experimental results showed that this flaw could be detected by the equipment. The height detection technique for this system and preliminary experiments conducted using the developed system are also covered in this report. By using the laser trigonometry method, the displacement of profile height was detected with sufficient accuracy.