International Business Machines Corporation

Bernardo Hernandez

Michael J Palmer

Raymond R Horton

Ismail C Noyan

Peter Alfred Gruber

Arthur R Zingher

Thomas George Ference

Mark B Ritter

Frederick G Weindelmayer

A high efficiency thermal interposer comprising a first hollow disk and second hollow disk, held together by thermally isolating fasteners. The fasteners keep the disks from touching one another. In an illustrative embodiment of the invention, the first disk is the low temperature disk portion and the second disk is the high temperature disk portion of the heat shield. Furthermore, according to a preferred embodiment of the invention, the space between the disks is filled with small thermally conductive particles (e.g., stainless steel spheres) which are in thermal contact with the high temperature disk; but which are not in contact with the low temperature disk. The thermal interposer/heat shield includes means for introducing cold jets of air into the cavity containing the particles, means for circulating the air therebetween, and means through which the air can exit from the cavity to carry away the heat picked up from the particles inside the cavity. The novel thermal interposer has a low mass, is compact and can achieve a temperature drop that will permit high powered HAT devices to be used in conjuction with temperature sensitive electronic orientation means, such as robot arms.

High efficiency thermal interposer

A soldering tip overcomes the gravitational effects on molten solder and supplies a large molten solder sphere for contact with a surface to which solder is to be applied. A conical or cylindrical spiral or helix of solder-wettable material, preferably in the form of a compressional spring is attached to the soldering tip with the central axis of the helix aligned with the axis of the soldering tip, preferably by welding. Solder supplied to the soldering tip flows between the coils of the helix and forms a meniscus at the lower end of the helix so that only the molten solder meniscus touches the surface during application of solder. The increased surface tension acts to overcome gravitational effects and assures a more even flow of solder to the surface.

Solder application system using helix to control solder meniscus

A method and apparatus for removing wires bonded between chip contact pads and substrate contact pads using an alternating fluid flow is described. The fluid flow is preferably air. A nozzle having a plurality of air jets within a chip accommodating cavity is disposed over the chip to enclose the chip contact pads, the substrate contact pads and the wires bonded therebetween. Air is forced through the plurality of jets to cause an alternating clockwise and counter clockwise air flow which bends the plurality of wires back and forth until they fatigue at the contact points to the chip contact pads in a substrate contact pads which results in the wires being substantially simultaneously severed therefrom. The nozzle has an aperture out through which the air escapes carrying the severed wires therewith for collection in a filter.

Wirebond removal apparatus using alternating fluid stream

An apparatus and method are described for injection molding solder mounds onto electronic devices. The apparatus has a reservoir for molten solder which is disposed over a cavity in an injection plate. The injection plate is disposed over a mold having an array of cavities therein into which solder in injection molded. The mold is disposed over a workpiece, such as a semiconductor chip or a semiconductor chip packaging substrate. The cavities in the mold are aligned with electrical contact locations on the chip or substrate. The workpiece is heated and the molten solder is forced under gas pressure into the cavity in the injection plate disposed above the array of cavities in the mold. The molten solder is forced into the array of cavities in the mold. The injection plate is advanced to slide over the mold to wipe away the excess solder above the mold at a plurality of wiping apertures in the injection plate. The injection plate is further advanced to a location having a nonsolder wettable surface at which location the injection plate is removed. The mold is then removed to leave solder mounds disposed on the workpiece. The workpiece can be a semiconductor chip, a semiconductor chip packaging substrate or a dummy substrate onto which the injected molded solder adheres such as a polymer layer to form a carrier substrate for a solder mound array which can be subsequently transferred to a substrate such as a semiconductor chip or a semiconductor chip packaging substrate. The apparatus and methods of the present invention can be integrated into an automated manufacturing system for depositing an array of solder mounds onto a substrates.

Growing community of inventors

Norwalk, CT, United States of America

Bernardo Hernandez