Patent ID: 6402497
Filing Date: 2002-06-11
Classification: B29C

Abstract:
A mold clamping device for sealing a semiconductor element with a resin, comprising:a support base; a middle platen fixedly supported by said support base; a lower metallic mold fixedly secured upon an upper surface of said middle platen; a plurality of tie-bars vertically extending through and slidably supported by said middle platen; a moveable platen fixedly secured to top end portions of said tie-bars; a member disposed beneath a lower surface of said movable platen, said member being thicker in the vertical direction at the center of said member than at the edges of said member; an upper metallic mold disposed beneath said member to oppose said lower metallic mold, said lower metallic mold and said upper metallic mold defining a cavity for accommodating a semiconductor element during a resin molding and sealing process; a horizontal connecting bar member connecting lower ends of at least two of said tie-bars; a quadrilateral linkage mechanism defining a pantograph having a form of a collapsible rhombus lying on a vertical plane; a first and second annular link rotatably coupled to said quadrilateral linkage mechanism, respectively, said first and said second annular links each having an inner thread formed on an inner surface thereof; a rod-shaped threaded member having a left-handed first thread and a right-handed second thread formed at an outer side surface thereof, said first and second threads engaging with said inner thread of said first and said second annular links, respectively, whereby rotation of said rod-shaped threaded member in a first direction drives said annular links toward each other upon said rod-shaped threaded member, and rotation of said rod-shaped threaded member in a second direction opposite to said first direction drives said annular links away from each other upon said rod-shaped threaded member; and a driving means for driving said rod-shaped threaded member selectively in and said first and said second directions, thereby lowering said upper metallic mold toward said lower metallic mold and raiding said upper metallic mold away from said lower metallic mold, respectively, a driving force being transmitted from said driving means to said upper metallic mold through said rod-shaped threaded member, said annular links, said quadrilateral linkage mechanism, said horizontal connecting bar member, said tie-bars, and said movable platen.