| 摘要 |
PURPOSE:To reduce generation of the frictional heat to be caused by the rotation of a drill to prolong a lifetime of a drill and improve the accuracy by using a laminated plate which consists of kraft paper or regenerated paper and unsaturated polyester resin as a presser plate to be used for drilling a wiring board. CONSTITUTION:Kraft paper and regenerated paper can be used as the base material, and a cost thereof is low, and when they are laminated to form a laminated plate, layers of the kraft paper and the resin are easy to be separated to prevent a phenomenon that the resin is penetrated into the paper to form the even structure. Hard resin layers can be therefore reduced to improve the drilling property of a drill 2. Especially, since phenol resin laminated plate to be used as a presser plate 3 at present is made of prepreg, which is obtained by impregnating the resin into the base material, molded under the high temperature and high pressure condition, the base material layer and the resin layers are evened, and since the resin is distributed evenly in the whole of the plate, resistance against the rotation of the drill becomes larger. In the case that the polyester resin is used, since the molding pressure at the time of molding the laminated plate is almost zero, it is extremely profitable. In the case that the lubricating agent is added, resistance against the rotation of the drill is more reduced. |
