Abstract: In a method of manufacturing a semiconductor device, an electrode layer is formed on a surface of a semiconductor substrate, and a resin insulation layer is formed on the surface of the semiconductor substrate so that the electrode layer can be covered with the resin insulation layer. A tapered hole is formed in the insulation layer by using a tool bit having a rake angle of zero or a negative value. The tapered hole has an opening defined by the insulation layer, a bottom defined by the electrode layer, and a side wall connecting the opening to the bottom.

Abstract: In a method of manufacturing a semiconductor device, an electrode layer is formed on a surface of a semiconductor substrate, and a resin insulation layer is formed on the surface of the semiconductor substrate so that the electrode layer can be covered with the resin insulation layer. A tapered hole is formed in the insulation layer by using a tool bit having a rake angle of zero or a negative value. The tapered hole has an opening defined by the insulation layer, a bottom defined by the electrode layer, and a side wall connecting the opening to the bottom.

Abstract: A burr removing device for removing a burr, which is formed at a connection between a first hole and a second hole that are angled relative to each other inside a workpiece. According to the burr removing device, a generated high-density energy beam is converged by a converging lens, which is located outside of the first and second holes of the workpiece. Then, the converged high-density energy beam is reflected toward the burr by a one reflecting mirror, which is located in one of the first and second holes.

Abstract: A discharging nozzle is provided in an inside space of a metal cylinder for supplying an assist gas from an inside of the metal cylinder. The gas discharging nozzle shuts a high density energy beam intruding into the inside space of the metal cylinder through a hole, so that the energy beam is prevented from being emitted to an opposite side inner surface of the metal cylinder. Dross formed during the cut-machining is drifted and swept to the outside by an assist gas flowing out from the inside space of the metal cylinder through the hole, and is blown out by the assist gas flowing on an outside surface of the metal cylinder around the hole, thereby preventing the dross from sticking to peripheral area of the hole.

Abstract: A discharging nozzle is provided in an inside space of a metal cylinder for supplying an assist gas from an inside of the metal cylinder. The gas discharging nozzle shuts a high density energy beam intruding into the inside space of the metal cylinder through a hole, so that the energy beam is prevented from being emitted to an opposite side inner surface of the metal cylinder. Dross formed during the cut-machining is drifted and swept to the outside by an assist gas flowing out from the inside space of the metal cylinder through the hole, and is blown out by the assist gas flowing on an outside surface of the metal cylinder around the hole, thereby preventing the dross from sticking to peripheral area of the hole.