Study for a defect detection system with capacitance on the printed wiring board

Recently consumer products focused on electrical devices are miniaturized and its packaging size becomes smaller and smaller such as cellular phones, digital cameras and etc. It means that an innovation to miniaturize the printed circuit board (PCB) is required. Along with this requirement of the minute PCB, a technique of the fine pattern design and tiny component mounting on the board must be newly developed. Regarding a growing trend of the minute and multi-layers design of the PCB, a line width of the circuit pattern is reduced up to 25 [μm] and then the defect inspection is proposed as the most important technology. Therefore we study a new system development for the defects which are difficult to inspect on the fine patterns. To find the defects at a continuity test is done by the non-contact method and the inspection for finding the position of the defect is request. In this report, as the way of the continuity test by using the probe, we have an experiment of the contacting method. Moreover, we can compare it with the non-contact method on the board.