Mitsubishi Denki Kabushiki Kaisha

Kunito Sakai

Takashi Takahama

Hirozoh Kanegae

Sadamu Matsuda

Kazuharu Oshio

Yutaka Morita

Sueyosi Tanaka

Yasutugu Tutumi

Akinobu Tamaki

A molding machine comprises 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.

Encapsulation method

A molding apparatus having an upper mold, a lower mold, and a cylindrical mold cavity defined between the upper mold and the lower mold and adapted to receive a molding material such as epoxy resin. An annular recess is defined in the lower mold adjacent to the mold cavity. A gasket is fit in the recess and made of lead. An oil passage is defined in the lower mold. Silicon oil as a pressure medium is fed to the recess through the oil passage so as to press the gasket against the upper mold. Then, the gasket is deformed to form a seal around a portion of the mold cavity where the upper and lower molds mate with one another. An annular spacer is placed in the bottom of the recess. An annular groove is defined below and along the bottom of the recess so as to allow the silicon oil to flow below and along the annular spacer, whereby sufficient pressure is exerted uniformly on the gasket to cause deformation of the gasket.

Molding apparatus and method in which a mold cavity gasket is deformed

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.

Molding machine and method

A method for packaging semiconductor devices in resin uses a mold having a pot and cavities, a vacuum pump for drawing off the air contained in the pot and the gases emitted from a resin tablet placed in the pot, and a pressing piston for pressing the resin tablet to feed the resin to the cavities. The pot has a volume which is greater than the maximum volume to which the heated resin tablet expands in a vacuum. The method includes the steps of placing the resin tablet in the pot, heating the resin under an applied vacuum until it expands to a sufficient extent to draw away gas trapped in the heated resin tablet, pressing the heated resin to the cavities to surround semiconductor devices placed therein, and curing the resin.

Method for packaging semiconductor devices in a resin

A resin-molding tablet for use in resin-molding semiconductor devices has a tablet body formed of powdered or particulate resin. The particles of the resin are compacted such as to form voids between adjacent particles. At least the outer peripheral region of the tablet is fused such that the resin particles are welded together to form a continuous layer of fine and impervious structure substantially free of open pores. The internal air trapped in the voids of the tablet is drawn and removed before the tablet is fused so that the tablet is substantially free of air. The tablet is produced by placing a particulate or powdered resin material in a vacuum vessel so as to allow the internal air in the resin material to be drawn outside, and then applying pressure and heat to the resin material so that at least the peripheral region of the mass of the particulate resin is fused to weld together. The tablet thus formed is melted and forcibly fed into a vacuum die cavity in which a semiconductor device to be molded is accommodated, thereby to hermetically seal the semiconductor device. Thus, a semiconductor package having substantially no voids is produced.

Method for producing a tablet for resin-molding semiconductor devices

Tablet for resin-molding semiconductor devices

A method of producing a semiconductor device having a light transparent window, includes: a process of die bonding a chip onto a lead frame; a process of attaching a wall surrounding a picture element to either of the external contour surface of the surface of the chip or the light transparent window surrounding the picture element; a process of inserting the chip and the light transparent window into a metal mold in such a manner that an empty closed space is produced between the chip and the light transparent window via the wall; and a process of plastic molding the device except for the light transparent window by filling resin into the metal mold and making the resin hardened.

Method of producing a semiconductor device having a light transparent

A semiconductor device and a method for manufacturing a semiconductor device of a type having a resin package and a window in the package such as a quartz glass window transparent to ultraviolet rays. A semiconductor chip is bonded onto a surface of a die pad of a lead frame. A softened resin is then extruded from the opposite surface of the die pad through gaps between the die pad and the leads with the extrusion being carried out in an inert gas atmosphere. An inner package member is thus formed surrounding the semiconductor chip. An outer package member, made of a thermosetting resin having a weight ratio of resin to filler less than that of the inner package, is molded around the chip assembly and inner package.

Method of resin encapsulating a semiconductor device

A semiconductor device includes an electronic component in a hollow portion provided between two packing members each comprising a laminated structure. A laminated structure has a metallic layer and an insulating layer. The laminated structure can further have a reinforcing layer. One end surface of the laminated structure is an insulating layer. The insulating layers of these laminated structures oppose each other with peripheral portions thereof hermetically connected, so that the hollow portion containing the electronic component is airtight. A metallic layer is formed of a metal such as aluminum or an alloy thereof, an insulating layer is formed of organic material and the like and a reinforcing layer is formed of a fiber, a thermosetting resin, a thermoplastic resin and the like. The electronic component contained in the hollow portion is positioned to avoid contact with the packing members. The electronic component is electrically connected to the exterior through lead wires interposed between the contact surfaces of the two packing members.

Growing community of inventors

Hyogo, Japan

Kunito Sakai