Resin sealing method for a semiconductor device

A resin sealing method for sealing an underfilled portion of a molded piece in which a semiconductor chip is mounted on a substrate, said method comprising the steps of:

• providing a first transfer mold and a second transfer mold;
• providing a first release film on said first transfer mold;
• placing said molded piece in said second transfer mold;
• providing a second release film on said second transfer mold, but not between said molded piece and said second transfer mold;
• clamping said molded piece between said first and said transfer molds, such that said first and said second release films close a perimeter of said underfilled portion except a portion to which a gate continuous to said underfilled portion is connected;
• and
• feeding said sealing resin under pressure to said underfilled portion.

A resin sealing method for sealing a joining portion between a semiconductor chip and a substrate by feeding a sealing resin under pressure to an underfilled portion of a molded piece including the substrate and the semiconductor chip on the substrate, said method comprising the steps of:

• providing a mold having a portion in which the sealing resin is supported and movable in a mold opening/closing direction through an elastic material;
• clamping the molded piece to close a peripheral portion of the underfilled portion with a release film except a portion to which a gate continuous to the underfilled portion is connected;
• clamping the sealing resin by the mold against an urging force of the elastic material;
• and
• feeding the molten sealing resin under pressure to the underfilled portion of the molded piece by a pressure force of the elastic material through the mold and the release film, to seal the joining portion.