Study on drilled hole quality in small diameter drilling of GFRP
Aoyama Eiichi; Hirogaki Toshiki; Inoue Hisahiro; Gunjima Munehisa; Nobe Hiromichi; Kitahara Youji; Katayama Tsutao
Abstract:In recent years, printed wiring board (PWB) is used in most of electronic products, such as office automation apparatus and home electronics. As these electronic products become smaller in size and higher in function, it has been required for the packaging density of PWB to be improved. So, it is necessary that the hole is made small in drilling and that the pattern is made fine on a circuit. Specially, the small diameter drilling in PWB is one of the important processes in forming circuit, because the drilled hole quality is required for improving the reliability of through-hole plating. Consequently, in order to develop the reliability of smaller diameter drilling in PWB, it was needed to establish a new method to grasp the relation between the drilled hole quality and cutting condition. So, the picture processing method was applied to observe the internal damage by using transmitted light through GFRP. Attention was paid to the relation between the internal damage and surface roughness of the hole, and the relation between the drilled hole quality and internal damage at various drilling conditions was examined. The drilled hole quality has been made clear by this method. Key Words:hole quality, drilling, GFRP, PWB, picture processing, internal damage, surface roughness