Patent ID: 9431273
Filing Date: 2016-08-30
CPC Classification: H01L

Claim Text:
1. A method of manufacturing a resin-encapsulated semiconductor device, comprising: preparing one of a frame and an electroformed substrate including a plurality of units each including, as one unit, a die pad portion and a plurality of lead portions arranged so as to be opposed to the die pad portion; attaching a sealing sheet to a first surface of the one of the frame and the electroformed substrate; forming a soluble film on a second surface of each of the plurality of lead portions, which is on an opposite side to the first surface; mounting a semiconductor element to the die pad portion of the one of the frame and the electroformed substrate; connecting together the plurality of lead portions and electrodes on a surface of the semiconductor element by thin metal wires; encapsulating the die pad portion, the semiconductor element, and the plurality of lead portions by an encapsulation resin and removing the sealing sheet so that a lead bottom surface part of each of the plurality of lead portions is exposed; dissolving and removing the soluble film to form a hollow portion in the encapsulation resin; immersing the one of the frame and the electroformed substrate into a plating bath to form a plating layer on the lead bottom surface part and a lead upper end part of the each of the plurality of lead portions; subjecting the plurality of lead portions to a first cutting from the first surface side to form a first groove that reaches the hollow portion; and subjecting the encapsulation resin to a second cutting from the second surface side opposite to the first surface side to separate a resin-encapsulated semiconductor device from the one of the frame and the electroformed substrate.