Mitsubishi Denki Kabushiki Kaisha

Ikuo Sasaki

Toshinobu Banjo

Osamu Nakagawa

Shoji Murakami

Koji Abe

Koji Yanagitani

Kenichi Onishi

A cathode roller mechanism comprises a tapered cathode roller for establishing an electrical connection to a semiconductor lead frame and an elastic, frictional pressure roller. The cathode roller comprises a tapered roller body defining a tapered side surface and an electrically conductive stopper disposed on the roller body and having an inner tapered electrode. The pressure roller is arranged so that the path of a drifted lead frame can be corrected, and the drift of the lead frame can be positively prevented by pressing the lead frame in such a manner that no drift of the lead frame occurs. In addition, an auxiliary electrode is provided on the inside of the tapered electrode, a third tapered surface is provided on the auxiliary electrode, and the width of the pressure roller is set to a length sufficient to press a corner of a molded portion of lead frame having the maximum width so that electrical continuity, i.e., the connection between the lead frame and the electrode, can be stabilized, and the lead frame can be more stably made a cathode.

Cathode roller mechanism

A metal mold for plastic molding a semiconductor device by a transfer-molding method with the use of thermo-hardening plastics. The mold includes a pot section into which plastic is injected; a cavity section where a product is formed; a runner section constituting a path for the plastic from the pot section to the cavity section; a gate section provided between the runner section and the cavity section so as to reduce the cross-sectional area for the flow of the plastic which flows therethrough from the runner section to the cavity section; a flow restriction section provided in the path of the runner section so as to reduce the cross-sectional area of the flow of plastic.

Method of molding a semiconductor device

Growing community of inventors

Itami, Japan

Ikuo Sasaki