Means For Transfer Molding Patents (Class 425/544)
  • Patent number: 5645864
    Abstract: A resin encapsulating molding die for manufacturing a semiconductor device includes a cavity piece having a cavity on which a lead frame with a mounted semiconductor element may be placed, with the semiconductor element in the cavity, and a gate piece having a gate portion including a sub-runner through which a molten resin for encapsulating the semiconductor element is introduced into the cavity, the gate piece being detachable from the cavity piece. The molding die also includes a sealing dam disposed adjacent the sub-runner for blocking flow of molten resin from the sub-runner toward leads of the lead frame. The sealing dam may be a clamp structure for clamping the leads closest to the gate portion, the sealing dam and cavity piece may be a continuous unitary structure, and the sealing dam may have a parting surface substantially coplanar with a parting surface of the cavity piece.
    Type: Grant
    Filed: April 25, 1996
    Date of Patent: July 8, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Noriaki Higuchi
  • Patent number: 5635220
    Abstract: A molding die for sealing a semiconductor element with a resin includes an upper and a lower mold half. A leadframe having a resin passage aperture is sandwiched between the lower mold half and the upper mold half. The lower mold half has a lower runner space, a lower cavity, and a lower gate provided between the lower runner space and the lower cavity. The upper mold half has an upper resin well, an upper cavity, and an upper gate provided between the resin well and the upper cavity. The length of the upper resin well in the direction of the flow of resin is equal to or greater than the distance from the lower gate to the front edge of a lower runner rising slope, to thereby obtain a final product which is free from resin burrs formed in the upper resin well.
    Type: Grant
    Filed: September 19, 1995
    Date of Patent: June 3, 1997
    Assignee: NEC Corporation
    Inventors: Atsuhiko Izumi, Takehito Inaba, Kousuke Azuma
  • Patent number: 5626887
    Abstract: A plunger (22), used in a standard mold, has a vent seal device (23) and spring (24) that evacuates air through an exhaust port 26a, and channels 26 and 26b from the mold prior to moving the mold compound into the runner 27.
    Type: Grant
    Filed: October 24, 1994
    Date of Patent: May 6, 1997
    Assignee: Texas Instruments Incorporated
    Inventors: C. H. Chou, T. H. Wang, C. S. Chen
  • Patent number: 5624691
    Abstract: The invention is to a transfer mold design utilized with conventional transfer encapsulation. The design utilizes a varying runner cross section with an intermediate varying depth well or reservoir from which a constant gate depth and gate entry angled to the mold cavities is employed. The method and apparatus of the invention is applicable to single and multiplunger molding utilizing thermoset and thermoplastic encapsulants for semiconductors.
    Type: Grant
    Filed: June 21, 1994
    Date of Patent: April 29, 1997
    Assignee: Texas Instruments Incorporated
    Inventors: George A. Bednarz, Teong Y. Lim
  • Patent number: 5609889
    Abstract: A printed wiring board with either a pin grid array, a ball grid array, a land grid array, etc. of electrical contacts is prepared with a heat sink attached in the usual manner. A passage is provided either in the printed wiring board or in the heat sink so that during the transfer molding process, fluid molding compound passes latitudinally under the heat sink into a cavity below the heat sink. The mold is provided with a biased plug that exerts pressure on the heat sink or printed wiring board to prevent molding compound from covering the heat sink. The biased plug also accommodates variations in the thickness of the printed wiring board.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: March 11, 1997
    Assignee: Hestia Technologies, Inc.
    Inventor: Patrick O. Weber
  • Patent number: 5597523
    Abstract: 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.
    Type: Grant
    Filed: August 18, 1994
    Date of Patent: January 28, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kunito Sakai, Kazuharu Oshio, Hirozoh Kanegae
  • Patent number: 5522713
    Abstract: A direct drive electro-mechanical press for encapsulating semiconductor devices has at least a clamping axis and a transfer axis. The clamping axis has a planetary roller screw coupled to a tie bar platen assembly on which at least one top mold is mounted. A two-speed gearbox is further coupled to the clamping axis for switching between a high speed mode and a high torque mode along the clamping axis. The two-speed gearbox has a high speed clutch coupled to a speed reducer and a high torque clutch respectively. The transfer axis is slidably located above the clamping axis; the transfer axis has another planetary roller screw coupled to a bottom platen on which at least one bottom mold is mounted. The transfer axis transfers the molding resin from the pot into the cavities formed when the top and bottom molds are clamped together.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: June 4, 1996
    Assignee: Advanced Systems Automation PTE Ltd.
    Inventor: Tiang S. Lian
  • Patent number: 5520874
    Abstract: A plunger (22), used in a standard mold, has a movable piston (23) and spring (24) that reduce the cull space when piston (23) is pressed downward into the cull mold compound.
    Type: Grant
    Filed: September 29, 1994
    Date of Patent: May 28, 1996
    Assignee: Texas Instruments Incorporated
    Inventors: C. H. Chou, T. H. Wang, C. S. Chen, Y. C. Chen, S. P. Ko
  • Patent number: 5516271
    Abstract: In an apparatus for resin transfer molding, the resin is introduced into a heated resin pot, and a piston member is driven through the resin pot to displace the resin into a heated resin line. The temperature of the resin in the resin pot is substantially constant, and is above room temperature but below the catalyzing temperature of the resin. The preheated resin flows from the resin line into a preheater, which heats the resin to molding temperature and catalyzes the resin, and the catalyzed resin is then introduced into the mold cavity of a resin transfer mold containing a structural preform. The resin is maintained at a substantially constant pressure within the heated resin line, and the movement of the piston member is continuously monitored during the resin transfer process. The resin transfer process is terminated when the rate of movement of the piston member decreases below a predetermined minimum value approaching zero.
    Type: Grant
    Filed: December 14, 1993
    Date of Patent: May 14, 1996
    Assignee: United Technologies Corporation
    Inventors: Richard D. Swenor, Peter Hryniewicz
  • Patent number: 5507633
    Abstract: In an apparatus for molding resin to seal an electronic part, a sealed space portion is formed between molding surfaces of an upper mold section and a lower mold section by covering an outer side periphery of a pot, a resin path and a cavity. A resin tablet is heated at its bottom portion and peripheral portion in the pot of the lower mold section to expand upwardly from its top portion. Air and moisture included inside the resin tablet is expelled into the sealed space portion which is evacuated including any air and moisture inside the sealed space portion, whereby the formation of voids in the molded resin body is avoided.
    Type: Grant
    Filed: July 8, 1994
    Date of Patent: April 16, 1996
    Assignee: Towa Corporation
    Inventors: Michio Osada, Yoshihisa Kawamoto
  • Patent number: 5501588
    Abstract: A mold for a semiconductor package having a port for feeding resin which can be fixed either in an upper mold (1) or a bottom mold (2) corresponding to the location of the flange tip so that the operating rate of the equipment is increased to achieve high productivity.
    Type: Grant
    Filed: April 17, 1995
    Date of Patent: March 26, 1996
    Assignee: Han-Mi Mold & Tool Co., Ltd
    Inventor: Nho K. Kwak
  • Patent number: 5501587
    Abstract: A molding machine is provided for a semiconductor package. The machine has two transfer rods for compressing resin into a leadframe of the mold. One transfer rod will move resin into the mold when the rod is moved downward and the second transfer rod will move resin into the mold when the rod is moves upwardly. Means are provided for selectively operating the transfer rods as needed depending on the type of mold used.
    Type: Grant
    Filed: September 1, 1994
    Date of Patent: March 26, 1996
    Assignee: Han-Mi Mold & Tool, Co., Ltd.
    Inventor: Nho K. Kwak
  • Patent number: 5480296
    Abstract: An improved transfer molding apparatus is provided for molding a preheated resin under pressure to thereby encapsulate a small element, such as a semiconductor device or package. In one aspect of the invention, the improvement consists of providing a shortened pot into which a piston is forcibly pressed to generate a flow of preheated resin in the encapsulating process, the improvement comprising the replacement of a single-element top drive plate, as found in a conventional apparatus, by a two-piece top drive plate which enables a shortening of the pot and corresponding reduction in the amount of air that would otherwise be trapped between the plunger and the resin during the process. The elimination of this air significantly reduces foaming, porosity, voids, and other defects in the cured resin which finally surrounds the electrical elements encapsulated thereby.
    Type: Grant
    Filed: June 22, 1994
    Date of Patent: January 2, 1996
    Assignee: Goldstar Electron Co., Ltd.
    Inventor: Keun Y. Jang
  • Patent number: 5478226
    Abstract: An automatic plunger apparatus is disclosed for compressing molten plastic into a cavity for forming an encapsulated semiconductor device. A compressing device drives a plunger member in order to compress and direct molten plastic to flow in a forward direction into the cavity. An overload compensator is coupled to the plunger member for permitting the plunger member to withdraw in a reverse direction when the plunger member is prevented from compressing and directing the molten plastic to flow in the forward direction into the cavity. The overload compensator includes a first member retained within a second member for transferring the force from the compressing device into motion of the plunger member.
    Type: Grant
    Filed: April 20, 1994
    Date of Patent: December 26, 1995
    Inventor: Richard H. J. Fierkens
  • Patent number: 5460503
    Abstract: A mold for forming coreless armatures having an upper mold and a lower mold. The lower mold has a mold cavity for receiving a shaft capable of supporting windings of a coreless armature. An elastic ring plate is placed between the upper and lower molds and is adapted for being compressed therebetween. The elastic ring plate is further adapted to contact terminal ends of the windings as they extend outside of the mold cavity, and to seal said mold cavity with the terminal ends extending therefrom.
    Type: Grant
    Filed: January 19, 1994
    Date of Patent: October 24, 1995
    Assignee: Olympus Optical Company, Limited
    Inventors: Goro Kitajima, Naohiro Hanaoka, Mitsuo Nasu
  • Patent number: 5460502
    Abstract: An improved plunger apparatus used in a resin molding device for encapsulating electronic components. At least one annular recess is located in the bottom side of the plunger. The annular recess redirects the plasticized resin to flow towards the mold cavities in the molding device and away from the interface between the plunger and the cylinder of the molding device, thereby optimizing the flow of resin to the cavities and reducing the tendency of excess gas and resin to flow away from the cavities. At least one flat side is located in the lengthwise surface of the plunger. The flat side forms an enlarged clearance in the interface between the flat side and the cylinder of the molding device. The enlarged clearance receives and provides an outlet for any excess gas or resin that flows in the interface. The improved plunger still stably guides within the cylinder, and the improved plunger allows the molding apparatus to encapsulate electronic components more economically, efficiently, and effectively.
    Type: Grant
    Filed: September 15, 1993
    Date of Patent: October 24, 1995
    Inventor: Michael L. Majercak
  • Patent number: 5454705
    Abstract: A metallic mold for molding semiconductor package including a pair of cavity blocks capable of molding two types of semi conductor packages in order to reduce manufacturing cost. The metallic mold includes an upper cavity block to be inserted in its normal state and its turned over state in an upper chase block mounted on a lower surface of a top mold base of an upper mold die which is formed at its upper surface with one type of cavities and at its lower surface with another type of cavities, and a lower cavity block to be inserted in its normal state and its turned over state in a lower chase bock mounted on a bottom mold base of a lower mold base which is formed at its upper surface with cavities mating with the another type of cavities of the upper cavity block and at its lower surface with cavities mating with the one type of cavities of the upper cavity block.
    Type: Grant
    Filed: December 21, 1992
    Date of Patent: October 3, 1995
    Assignee: Goldstar Electron Co., Ltd.
    Inventor: Seung Dae Back
  • Patent number: 5451154
    Abstract: An apparatus for encapsulating with plastic lead frames having chips arranged thereon includes mutually movable mold halves (102, 103). In the closed position a mold cavity is bounded, in which molding material is arranged under pressure via a runner. the pressure is provided by a plunger-cylinder (134-133) which carries up the molding material. Leaking molding material can result in adhering of the plunger to the cylinder wall, which is prevented according to the invention in that the outer wall of the plunger (134) is provided with scraping edges which scrape clean the inner wall of the cylinder (133) during operation.
    Type: Grant
    Filed: June 13, 1994
    Date of Patent: September 19, 1995
    Assignee: Fico B.V.
    Inventor: Hendrikus J. M. Schaars
  • Patent number: 5435953
    Abstract: In a method for molding resin to seal an electronic part, a sealed space portion is formed between molding surfaces of an upper mold section and a lower mold section by covering an outer side periphery of a pot, a resin path and a cavity. A resin tablet is heated at its bottom portion and peripheral portion in the pot of the lower mold section to expand upwardly from its top portion. Air and moisture included inside the resin tablet is expelled into the sealed space portion which is evacuated including any air and moisture inside the sealed space portion, whereby the formation of voids in the molded resin body is avoided.
    Type: Grant
    Filed: December 21, 1993
    Date of Patent: July 25, 1995
    Assignee: Towa Corporation
    Inventors: Michio Osada, Yoshihisa Kawamoto
  • Patent number: 5431854
    Abstract: Method for pressing a plastic (6), which cures by means of a reaction, from a displacement chamber (4) via at least one injection channel (3) and a gate (2) to a mould cavity (1), said method at least comprising the following steps: pressurising the plastic (6) with an amount of a pressing auxiliary (7) in the displacement chamber (4); pressing the plastic (6) into the mould cavity (1); and allowing the plastic to cure under pressure in the mould cavity, the pressing auxiliary (7) being plastically deformable under the conditions of pressing and the amount thereof being sufficient to be pressed to the vicinity of the gate (2) of the mould cavity (1). Preferably the pressing auxiliary (7) is a thermoplastic.
    Type: Grant
    Filed: July 20, 1994
    Date of Patent: July 11, 1995
    Assignee: "3P" Licensing B.V.
    Inventor: Ireneus J. T. M. Pas
  • Patent number: 5429488
    Abstract: Encapsulation molding equipment includes individual mold bases each having an elongated shallow recess which receives strip-like carriers supporting semi-conductor chips and like objects for encapsulation. Cavity inserts having various numbers of cavities of different size and dimension individual to carriers having like numbers of chips of a range of size and dimension fit over the strips with each cavity on an insert surrounding the chip to be encapsulated. Gate and vent passages are formed on the surface of the insert spaced away from the mold base member for supply of resin from a central resin receptacle. Gate passages in the cavity inserts are configured to provide a restriction at the edge of each mold cavity, thereby accelerating the flow of liquid resin, rapidly filling the cavities and avoiding the entrapment of gas bubbles. The inserts have mold vent passages which allow for rapid venting of displaced gases from the cavities.
    Type: Grant
    Filed: July 15, 1994
    Date of Patent: July 4, 1995
    Assignee: Neu Dynamics Corporation
    Inventor: H. Karl Neu
  • Patent number: 5413471
    Abstract: A gas spring (602) is used as a buffer device in a resin-sealing apparatus for applying a compressive force to a plunger (15). In the gas spring (602), the compressive force at which a compression displacement starts is easily established as required, and the increasing degree of the compressive force with increasing compression displacement is established slowly without difficulty. Any errors in applying resin injection pressures to a plurality of plungers, due to variations in the amount of resin of tablets and in length of plungers, are absorbed in a wide range of the compression displacements thereof so that the resin injection pressures in practice are substantially equalized.
    Type: Grant
    Filed: February 11, 1993
    Date of Patent: May 9, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Shunji Yamauchi
  • Patent number: 5409362
    Abstract: Encapsulation molding equipment includes individual loading bars each having an elongated support surface which receives strip-like carriers supporting semi-conductor chips and like objects for encapsulation. Cavity inserts having plural rows of cavities of different size and dimension individual to carriers having like numbers of chips of a range of size and dimension fit over the strips with each cavity on an insert surrounding the chip to be encapsulated. Converging gate passages and vent passages are formed on the surface of the insert spaced away from the mold base member for supply of resin from a central resin receptacle to the cavities. Support of the cavity inserts independent of the loading bars and resilient mounting of the loading bars is disclosed. The mold is completed by an upper mold member which closes the mold and effects a seal between the mold parts and provides for delivery of encapsulating resin to the cavities in the cavity inserts.
    Type: Grant
    Filed: July 6, 1994
    Date of Patent: April 25, 1995
    Assignee: Neu Dynamics Corp.
    Inventor: H. Karl Neu
  • Patent number: 5409364
    Abstract: An apparatus for forming a modeling composition includes an extruder assembly for receiving and extruding a quantity of said modeling composition, and first and second mold assemblies of different sizes which are removably receivable on the extruder assembly for receiving modeling composition extruded therefrom. Each of the mold assemblies includes a rear plate portion and a front mold cavity portion which is preferably made of a transparent plastic material and adapted to be assembled with the plate portion thereof so that it cooperates therewith to define a mold cavity for receiving modeling composition therein from the extruder.
    Type: Grant
    Filed: December 9, 1993
    Date of Patent: April 25, 1995
    Assignee: Playskool, Inc.
    Inventors: Douglas A. Schultheis, Christina M. Beecher
  • Patent number: 5393215
    Abstract: Structural parts are produced from fiber composite preforms which are placed into a mold conforming to the shape of the desired part. A resin is then injected into the mold so as to fill the mold and encapsulate the fiber preform. The mold is evacuated prior to the injection step, and is rotated about a vertical axis during the injection step. The resin is maintained under pressure during the injection step, and the resin is hardened in the mold whereby net molded parts are formed.
    Type: Grant
    Filed: December 30, 1992
    Date of Patent: February 28, 1995
    Assignee: United Technologies Corporation
    Inventor: Thomas P. Donovan, Sr.
  • Patent number: 5370517
    Abstract: A die-stamped frame is fastened to a heat sink metal baseplate by wedging flexible tabs into receiving indentations of the baseplate while keeping the frame substantially in contact with the surface of the baseplate. The wire welding operations may then take place on the end of the fingers of the patterned metal frame while the same are solidly resting on the surface of the baseplate thus facilitating the welding. The backing-off of the metal frame from the surface of the heat sink baseplate takes place upon the closing of the mold used for encapsulating in resin the device. The injection of the resin and its solidification "freezes" the pins in the backed-off position imposed by the mold upon closing, thus ensuring the electrical isolation between the pins and the integral heat sink baseplate.
    Type: Grant
    Filed: April 9, 1993
    Date of Patent: December 6, 1994
    Assignee: SGS-Thomson Microelectronics s.r.l.
    Inventors: Paolo Casati, Carlo C. De Martiis, Giuseppe Marchisi
  • Patent number: 5366368
    Abstract: A preheaterless manual transfer mold die for encapsulating semiconductor elements in a process for packaging semiconductors. The preheaterless manual transfer mold die includes a multi-plunger assembly adapted for upward and downward movement to press the resin. A tablet loader is inserted into an upper mold die in order to charge tablets into plunger bushes of the upper mold die. After charging, the loader is pulled out of the upper mold die. The upper mold die receives the tablets from the tablet loader. The tablets are pressed by the multi-plungers. A lower mold die, clamped to the upper mold die, receives the resin tablets in a gel state from the upper mold die and fills cavities of chases with the resin to mold semiconductor elements.
    Type: Grant
    Filed: October 14, 1992
    Date of Patent: November 22, 1994
    Assignee: Goldstar Electron Co., Ltd.
    Inventor: Keun Y. Jang
  • Patent number: 5366364
    Abstract: A plastic molding apparatus for semiconductor devices includes a first evacuation passage via which an ejector chamber in a lower die chase block is evacuated through a lower die common surface table, a second evacuation passage via which an ejector chamber in the upper die chase block is evacuated through the upper die common surface table, and a third evacuation passage via which a parting chamber on a parting surface between the lower die chase block and the upper die chase block is evacuated through one of the lower die common surface table and the upper die common surface table. Since the evacuation passages are separate and the volume of the evacuation chamber is reduced, evacuation performance is improved and the size of the apparatus is reduced. The plastic packaging performance is also improved.
    Type: Grant
    Filed: August 31, 1993
    Date of Patent: November 22, 1994
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Sueyoshi Tanaka, Zyunzi Sakakibara, Yasutsugu Tsutsumi
  • Patent number: 5358396
    Abstract: A multi-functional mold which is used for encapsulating chips placed on lead frames is characterized by a chamber arranged in one of the mold halves in which an insert can be replaceably arranged. Depending on the use of the mold in the context of the so-called transfer molding method or injection molding method a different insert is placed in the chamber. In the application as transfer mold the insert includes an elongate member with a bore for guiding a plunger which makes encapsulating material liquid due to the pressure applied thereto and the increasing in temperature. In the application as injection mold the insert includes a member with a through-channel allowing a plasticized encapsulating material coming from a nozzle of an injection molding device to flow into the mold.
    Type: Grant
    Filed: September 7, 1993
    Date of Patent: October 25, 1994
    Assignee: Sony Corporation
    Inventor: Henricus B. Antonius Giesen
  • Patent number: 5356283
    Abstract: A metal mold for sealing a semiconductor device with a resin and including a shutter gate mechanism. The mold drives a shutter gate pin by using the ejection stroke of a conventional seal press, and therefore eliminates the need for an extra drive source. It follows that the mold can be implemented only if an existing facility is slightly modified, and it is lower in cost than conventional metal molds.
    Type: Grant
    Filed: October 14, 1993
    Date of Patent: October 18, 1994
    Assignee: NEC Corporation
    Inventors: Makoto Hamada, Hiroshi Ise
  • Patent number: 5344302
    Abstract: A tool for remotely obtaining an impression of a component surface. A support pole is used to position a mold plate having side walls against a component surface. One or more locating guides are provided with seals for sealing off bores in the component surface. A piston from a pneumatic cylinder attached to the support pole is used to force impression material into the space between the mold plate and component surface. An adhesive plate on the mold plate insures removal of the impression with the mold plate once the impression material has hardened. The surface condition of the component may be determined by inspection of the negative impression.
    Type: Grant
    Filed: September 3, 1993
    Date of Patent: September 6, 1994
    Assignee: B&W Nuclear Service Company
    Inventors: Edward M. Beehler, William H. Wolf
  • Patent number: 5328347
    Abstract: Device for injecting a plastic material into a mould cavity. In the device, the plastic is moved into the mould cavity by a plunger. The first part of the press stroke is used to transport the material and has to be carried out at relatively low pressure and over a relatively long transport path. The second part of the press stroke is used to fill the mould completely and takes place at relatively high pressure and virtually no stroke. According to the invention, the two movements are effected by different mechanisms which are specifically adapted to carry out these movements. In this arrangement, it becomes possible also to provide a safety coupling to prevent the device being overloaded while working at relatively low pressure.
    Type: Grant
    Filed: September 16, 1992
    Date of Patent: July 12, 1994
    Assignee: AMCO Hi-Tech B.V.
    Inventor: Gerardus J. M. Ten Vaarwerk
  • Patent number: 5326243
    Abstract: A molding apparatus having variable-volume cavities is provided. The apparatus consists of a lower and an upper mold defining a cavity for the lead frame, and having a conduit for forcing fluid plastic from a reservoir to the cavity for encapsulating an integrated circuit bonded to a lead frame. A pressure source is used to force the plastic from the reservoir through the conduit into both the upper and lower portions of the cavity surrounding the lead frame. The cavity of the mold is equipped with at least one piston-like insert slideably mounted in a bore hole in the surface of the cavity. The insert can be compressed or expanded to reduce or increase, respectively, the volume of the cavity. Thus, the final size of the cavity in the mold is determined by the position of the insert at the end of the encapsulation process. By allowing the expansion of the insert during a first phase of the molding operation, excess plastic is forced into the cavity.
    Type: Grant
    Filed: June 25, 1992
    Date of Patent: July 5, 1994
    Inventor: Richard H. J. Fierkens
  • Patent number: 5316463
    Abstract: Encapsulation molding equipment includes individual mold bases each having an elongated shallow recess which receives strip-like carriers supporting semi-conductor chips and like objects for encapsulation. Cavity inserts having various numbers of cavities of different size and dimension individual to carriers having like numbers of chips of a range of size and dimension fit over the strips with each cavity on an insert surrounding the chip to be encapsulated. Gate and vent passages are formed on the surface of the insert spaced away from the mold base member for supply of resin from a central resin receptacle. The mold is completed by an upper mold insert plate which closes the mold and effects a seal between the mold parts and provides for delivery of encapsulating resin to the cavities in the cavity inserts. Each mold base has a plurality of recesses, each of which receives a carrier strip and a cavity insert.
    Type: Grant
    Filed: November 24, 1992
    Date of Patent: May 31, 1994
    Assignee: Neu Dynamics Corporation
    Inventor: H. Karl Neu
  • Patent number: 5302101
    Abstract: A mold for resin-packaging electronic components on a pair of leadframes includes an upper mold member and a lower mold member. The mold has two parallel rows of molding cavities, and a row of resin supplying portions arranged between the respective cavity rows. The respective molding cavities have corresponding corner portions formed with injection ports which communicate with the respective resin supplying portions through runners. The respective cavity rows together with the leadframes received in the mold are displaced relative to each other longitudinally thereof by a predetermined amount.
    Type: Grant
    Filed: January 21, 1993
    Date of Patent: April 12, 1994
    Assignee: Rohm Co., Ltd.
    Inventor: Hiroyuki Nishimura
  • Patent number: 5297897
    Abstract: An apparatus for molding electronic components. The single-strip molding apparatus has a mold die formed from two mold halves which are movable relative to each other and can be closed upon one another. A leadframe for the component to be molded is placed into a recess in one of the mold halves. Molding material is heated and forced under pressure into the recess containing the leadframe. After the component is molded the mold is opened and the upper half of the mold is cleaned by a combined cleaning-discharge unit. Upon the return stroke of the cleaning-discharge unit, the molded component is removed and the lower half of the mold is cleaned.
    Type: Grant
    Filed: May 20, 1992
    Date of Patent: March 29, 1994
    Assignee: ASM Fico Tooling B.V.
    Inventors: Johannes L. G. M. Venrooij, Wouter B. Verwoerd, Wilhelmus H. J. Harmsen
  • Patent number: 5281121
    Abstract: A resin sealing apparatus includes upper and lower dies each having a chase block with a plurality of cavities into which molten resin is injected and a supporting member for supporting the chase block, the chase blocks of the upper and lower dies being fitted to each other, and a position determining member attached to each of the chase blocks so that the positions of the chase blocks are determined when they are assembled, wherein each of the chase blocks is attached to each of the supporting members so as to be movable in the vertical and lateral directions within given ranges.
    Type: Grant
    Filed: January 6, 1992
    Date of Patent: January 25, 1994
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yasutsugu Tsutsumi, Sueyoshi Tanaka, Yutaka Morita
  • Patent number: 5277567
    Abstract: A mixing head for a mold can receive two or more reactive synthetic resin components in a mixing chamber in which a mixing-chamber piston is displaceable to drive the residues into a first calming chamber communicating with the outlet of the mixing chamber. The first calming chamber also has a piston or plunger which can be advanced to drive the residues into a second calming chamber connected to the outlet of the first calming chamber. The second calming chamber has a second piston displacing the mixture into the mold cavity. Because the pistons of the first and second calming chambers can be retracted as the mixture flows through these chambers, a highly effective calming effect can be obtained for the turbulent mixture of the mixing chamber without throttling.
    Type: Grant
    Filed: June 24, 1992
    Date of Patent: January 11, 1994
    Assignee: Krauss Maffei AG
    Inventors: Adolf Bauer, Gereon Mertens
  • Patent number: 5275546
    Abstract: An apparatus for encapsulating an integrated circuit lead frame in plastic is disclosed. This apparatus includes an upper mold and a lower mold which, when properly joined together, define the package area of the lead frame as well as a reservoir for the molten plastic and a conduit and flow pocket for assuring uniform flow of plastic into the package area of the molds. The integrated circuit lead frame has a flow hole to allow the molten plastic to flow from the conduit into the flow pocket and into the bottom portion of the package area. The conduit also allows the molten plastic to flow directly to the top portion of the package area. With the plastic being more uniformly injected into both (top and bottom) package or cavity areas at once, the likelihood of air pockets, and to overcome wiresweep cavities and other imperfections in the final plastic package is reduced.
    Type: Grant
    Filed: December 30, 1991
    Date of Patent: January 4, 1994
    Inventor: Richard H. J. Fierkens
  • Patent number: 5204122
    Abstract: A mold system for use in resin encapsulation molding includes a cavity serving as a resin molding section in which small size electric elements such as semiconductor devices and electrical parts are encapsulated with a synthetic resin. The system also incudes at least one pot for receiving the synthetic resin material and melting the received synthetic resin material by heating, a cull section communicating with the pot and formed facing to an opening end face, and a conveying passage for communicating the cull section and the cavity to convey molten resin material through the cull section. The synthetic resin material is placed in the cavity and is heated to melt therein, and is extruded out of the pot by a plunger disposed in an axial direction of the pot. The inner bottom of the cull section facing to the opening end face of the pot is formed unevenly.
    Type: Grant
    Filed: January 23, 1992
    Date of Patent: April 20, 1993
    Assignee: Dai-Ichi Seiko Co., Ltd.
    Inventor: Akira Konishi
  • Patent number: 5204127
    Abstract: There is provided by the present invention a compression molding tool for producing apertures of a desired configuration in preselected locations in a compression molded article and a method for producing the apertures. The tool has first and second relatively movable tool halves each supporting a mold section. The mold section associated with the second tool half includes a movable portion that is relatively movable with respect to the second tool half. The first tool half is moved relative to the second tool half until the first and second mold sections engage each other to form a mold cavity therebetween. Devices for creating apertures are included on at least one of the mold sections and are extended into appropriately configured receptacles in the other mold section after the mold sections are engaged, but before molding material is forced by compression into the mold cavity.
    Type: Grant
    Filed: May 10, 1991
    Date of Patent: April 20, 1993
    Assignee: Composite Products, Inc.
    Inventor: Thomas J. Prusha
  • Patent number: 5192555
    Abstract: Apparatus and method for molding plastic articles including oscillating the molten plastic in the mold cavity. The method and apparatus is particularly suitable for use with a plurality of mold cavities supplied from a single feeding means or extruder. The disclosure teaches alternately feeding molten plastic to the mold cavity from at least one shooting pot while the flow of molten plastic to the mold cavity from the feeding means is discontinued.
    Type: Grant
    Filed: July 22, 1991
    Date of Patent: March 9, 1993
    Assignee: Husky Injection Molding Systems Ltd.
    Inventor: Robin Arnott
  • Patent number: 5182071
    Abstract: Molding carrier structures to leads of existing semiconductor packages is accomplished by molding at temperatures which maintain approximately matched thermal expansion between an encapsulating material and leads of the semiconductor package. The matched thermal expansion is provided by molding at temperatures below that which is required for glass transition of the encapsulating material. Molding at such temperatures is facilitated by a molding assembly that has a molding pot with an irregular shaped bottom which fluidizes the encapsulating material at low temperatures. Molding at temperatures that essentially match thermal expansion between the package's leads and the encapsulating material prevents damaging the leads of the package.
    Type: Grant
    Filed: December 14, 1990
    Date of Patent: January 26, 1993
    Assignee: Motorola, Inc.
    Inventors: James H. Knapp, Keith E. Nelson
  • Patent number: 5178885
    Abstract: A mold, adapted for resin transfer molding of composite articles, that has a seal for maintaining a vacuum resulting in denser composite parts. A mold body has at least two openings including an opening for removing the article therethrough. There are at least two mold closures adapted for closing the openings and two of the mold closures are in mutual contact within the interior of the mold. A seal is disposed between each closure and the mold body for sealing each mold closure to the mold body to continuously seal only a single surface. The mold has an improved seal for initiating and maintaining a vacuum thus reducing part porosity.
    Type: Grant
    Filed: June 20, 1989
    Date of Patent: January 12, 1993
    Assignee: United Technologies Corporation
    Inventors: Paul A. Vallier, Philip J. Ramey, Donald J. Baumgarten, Terry M. Boustead
  • Patent number: 5139728
    Abstract: A molding apparatus for encapsulating devices and having at least one molding pot wherein the pot has a configured bottom is used. The configured bottom serves as a shearing force against encapuslating material pellets which are pressed into the configured bottom by a plunger. The shearing force increases the fluidizing action of the pellets thereby lowering the viscosity of the encapsulating material so it easily enters cavities provided in the molding assembly and completely fills the cavities and encapsulates the devices without damage to the devices.
    Type: Grant
    Filed: March 25, 1991
    Date of Patent: August 18, 1992
    Assignee: Motorola, Inc.
    Inventor: John Baird
  • Patent number: 5125821
    Abstract: A measuring device for enabling an evaluation of a moldability of a thermosetting resin by determination of parameters suitable for high accuracy forecasting of flow and curing behaviors of the thermosetting resin within a metal mold, as well as a metal mold for molding a thermosetting resin and method for constructing runners of the metal mold which is effective to minimize if not prevent the occurrence of false in moldings. By utilizing unique or peculiar parameters of the thermosetting resin which are not influenced by a molding condition and by conducting a flow simulation with a metal mold having a flow passage of arbitrary dimensions using the determined values for the parameters, a forecasting of a flow in an actual metal mold is enabled so as to preselect optimum molding conditions and flow passage dimensions for a metal mold.
    Type: Grant
    Filed: October 31, 1989
    Date of Patent: June 30, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Junichi Saeki, Isamu Yoshida, Aizo Kaneda, Kazuhiro Sugino, Kunihiko Nishi
  • Patent number: 5123823
    Abstract: A reference pin (150) is provided on a bottom die (108) of a molding device (100). A lead frame (3) is carried with a chucking device (120) attached to an X-Y table mechanism (110). A hole (132) is formed in a stage (131) of the X-Y table mechanism. Respective images of the hole and the pin are detected by a TV camera (142) to control the relative position of the bottom die and the lead frame by driving the X-Y stage.
    Type: Grant
    Filed: January 15, 1991
    Date of Patent: June 23, 1992
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Toshinobu Banjo, Kouji Shika, Minoru Tanaka
  • Patent number: 5123826
    Abstract: A molding apparatus for encapsulating devices and having a molding pot wherein the pot has a configured bottom is provided. The configured bottom serves as a shearing force against encapsulating material pellets which are pressed into the configured bottom by a plunger. The shearing force increases the fluidizing action of the pellets thereby lowering the viscosity of the encapsulating material so it easily enters cavities provided in the molding assembly and completely fills the cavities and encapsulates the devices without damage to the devices.
    Type: Grant
    Filed: February 13, 1990
    Date of Patent: June 23, 1992
    Assignee: Motorola, Inc.
    Inventor: John Baird
  • Patent number: 5122045
    Abstract: A mold for molding a semiconductor package including a semiconductor chip mounted on a lead frame, wherein a major surface of the semiconductor chip is inclined relative to a surface of the semiconductor package, the mold includes a first mold half including a first mold cavity having a first mold surface and at least four first side surfaces, a second mold half including a second mold cavity having a second main surface extending substantially parallel to the first main surface and at least four second side surfaces extending substantially perpendicular to the second main surface, and a portion for supporting the lead frame and the semiconductor chip in the first and second mold cavities and position the major surface of the semiconductor chip in an inclined position relative to the second main surface, wherein the portion for supporting and positioning includes a first mating surface on the first mold half inclined relative to the first main surface and a second mating surface on the second mold half inclin
    Type: Grant
    Filed: May 9, 1991
    Date of Patent: June 16, 1992
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yutaka Tomisawa, Toshikazu Fukuda, Kazuhiko Inoue
  • Patent number: 5116212
    Abstract: A system for injecting molten material into a receiving apparatus, such as a moulding apparatus. The system according to the invention utilizes at least a melting chamber and an injecting chamber which are incorporated in a same housing and which are connected through a canal for transferring molten material contained in the melting chamber to the injecting chamber. The system further utilizes an apparatus for controlling the feeding of the injecting chamber and the triggering of the injecting apparatus when the injecting chamber has a predetermined quantity of molten material to be injected.
    Type: Grant
    Filed: September 6, 1990
    Date of Patent: May 26, 1992
    Inventor: Jean-Claude A. Clement-Demange