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US 5,395,226 AGranted
Molding machine and method
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsKunito Sakai, Kazuharu Oshio, Hirozoh Kanegae
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AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsKunito Sakai, Kazuharu Oshio, Hirozoh Kanegae
Estimating the term…
A molding machine includes a mold composed of lower and upper mold sections. A recess is defined in the lower mold section to receive a lead frame or other objects. The lead frame is sandwiched between the upper and lower mold sections. A mold cavity is defined in the lower mold section below the recess so as to receive a thermosetting resin or encapsulant. A gasket groove is defined adjacent to the mold cavity to receive a gasket. The gasket is subject to plastic deformation upon application of force. An oil chamber is communicated with the gasket groove and contains hydraulic oil. The hydraulic oil is pressurized to urge the gasket against the lead frame. As a result, the gasket is so deformed as to closely contact the surface of the lead frame and seal the mold cavity. The hydraulic oil is preferably mixed with thermoplastic resin in powder form.
A molding machine comprising a mold including first and second mold sections, at least one of said first and second mold sections including a recess adapted to receive an object, said first and second mold sections cooperating to sandwich the object therebetween, a mold cavity adapted to receive a molding material, said mold cavity being open to the object, a gasket groove defined adjacent to said mold cavity, a gasket received in said gasket groove, an oil chamber communicated with said gasket groove and containing a hydraulic oil, and means for pressurizing the hydraulic oil so as to urge said gasket against the object, said gasket being subject to plastic deformation when said gasket is pressed against the object.
Dependencies are inferred from the claim text.