Patent ID: 7618573

Claim:
A method of resin sealing of an electronic component in a cavity using an upper mold, a lower mold opposite to said upper mold, a middle mold provided between said upper mold and said lower mold and including a through hole into which said lower mold can be inserted, and a release film covering the cavity of said lower mold; said method comprising the steps of: attaching to said upper mold an unsealed substrate having said electronic component mounted thereon; inserting said lower mold into said through hole of said middle mold, while said release film is held between said lower mold and said middle mold; covering a whole surface of said cavity with said release film while said release film is sandwiched between said lower mold and said middle mold; clamping said upper mold together with said lower mold and said middle mold to immerse said electronic component in a melting resin in said cavity; curing said melting resin to form a cured resin; opening said upper mold, said lower mold and said middle mold; and removing a sealed substrate having said electronic component enveloped in said cured resin from said upper mold.