International Business Machines Corporation

Karl Hermann

Richard Francis Frankeny

Jerome A Frankeny

Javad Haj-ali-Ahmadi

Ronald E Hunt

Ronald L Imken

Verlon E Whitehead

Adolph B Habich

Paul A Farrar

Alfred Viehbeck

Stephen L Buchwalter

Caroline A Kovac

Mark F Bregman

Joseph LaTorre

Rolf Wustrau

Paige A Poore

John A Williamson

Jacqueline A Shorter-Beauchamp

Structure for mounting electronic devices thereon. The structure is fabricated from a plurality of substrates each having a thermally and/or electrically conductive core surrounded by a dielectric material. The substrates can be adherently placed together with the electrically conductive cores providing ground and power planes or the substrates can be mounted together with connectors electrically interconnecting adjacent substrates and spacing the adjacent substrates apart providing a space through which a fluid can flow to extract heat generated by the electronic devices mounted thereon. The conductive cores provide both power and ground planes to the structure and a means for thermally dissipating the generated heat.

Multi-level circuit card structure

Discrete computational elements are provided that will be connected to a base unit, and to one another or I/O devices, in order to configure a particular computer system. The base unit provides the electrical power required to energize the computational elements. A plurality of identically configured substrates are joined in a layered relation and are electrically connected with one another. These substrates are capable of being fabricated of different lengths such that they can extend outwardly from the computational element and may be connected to other computational elements. At least one integrated circuit will be placed on one side of the joined substrates and is electrically connected to each substrate layer. In this manner the ICs will be able to communicate with chips on other computational elements. A support member is also included that stiffens the plural substrate layers and independently distributes electrical power through voltage and ground potential planes, and interconnected substrate layers, to the chips. The support member will be disposed adjacent the substrate layers on a side opposite the ICs and independently attachable to the base unit by using electrical connection pins, a pluggable lip portion, or the like.

Modular component computer system

A memory module is built up from a power distribution assembly in the form of plates forming a capacitor of low inductance and a flexible circuit substrate. The circuit substrate is populated with precisely positioned contact pads for the power, read, write and address lines of memory chips that contact the substrate. Memory chips are fixed to heat spreaders and loaded into a chip holder which positions the chips for contact with the contact pads on the substrate. The substrate contact pads are plated to form dendritic crystals of palladium and the memory chips are provided with solder balls on the contact pads of the memory chip. The solder balls are held in contact with the contact pads by the compressive forces of clamping a heat sink over the heat spreaders for testing, and the assembly may be readily disassembled to replace any defective memory. The compression connection of the chips to the substrate may be relied on or the solder balls may be reflowed to establish permanent solder connections.

High density memory module

A method and apparatus is provided for testing integrated circuits and permanently affixing the ICs which are successfully tested to a product level carrier substrate. A modular test oven is used which allows the chips to be electrically and thermally tested with the chips non-permanently affixed to a carrier substrate. If all of the chips on the carrier substrate test good, then the temperature within the oven is elevated, thereby reflowing the solder balls and permanently affixing the chips to the carrier substrate.

Method for testing integrated circuits on a carrier substrate

A fluid actuated connector is provided with opposing circuit members that form the interior of the connector and which are substantially L-shaped with a substantially vertical portion facing a circuit card to be inserted into the connector and a substantially horizontal portion disposed onto a printed circuit board (PCB), such as a motherboard, or the like. The circuit members are disposed adjacent a frame and connector body such that a cavity is formed adjacent the circuit members and on a side opposite the electrical connection points being being contacted with the printed circuit card. The circuit membranes are formed of a single layer of dielectric material, to maintain the required resiliency, and have contacts, which may be in the form of 'bumps' etched into an electrically conductive material applied to the surface of the dielectric facing the circuit card. The side of the circuit membrane in communication with the cavity, which is filled with a non-compressible fluid, receives the force that deforms the circuit membrane. In order to increase the force actually transferred to the contact bumps, rigid pads are placed on the inside of the circuit membrane such that the pressurized fluid acts directly on the rigid pads. These pads are etched into a metal layer deposited on the dielectric and placed substantially opposite the electrical contact bumps, thereby allowing transfer of the force from the fluid directly to the bumps without the intermediate layers of an expandable tube, bladder, or the like.

Fluid actuated connector

A connector for connecting large numbers of contact points on a flat ribbon cable to corresponding contact points on a second flat ribbon ribbon cable is described. The connector is a rigid clamping device which encompasses the cables where they join and through the use of springs and force spreaders the connections at the cable interface are completed. The connections of the cables are disposed within a chamber within the connector and rigidly clamped to prevent movement or separation of the connections.

Super connector for connecting flat ribbon cables

This invention provides a heat sink assembly for cooling electrical and electronic circuits. A low cost assembly method is achieved by a pivotal assembly containing a heat sink which snaps into place adjacent to an electrical/electronic circuit which requires cooling. The snap-in heat sink assembly contains a resilient heat transfer material which is exposed to the devices requiring heat removal by windows or other openings in a plate which is disposed between the heat transfer material and the snap-in frame.

Pivotal heat sink assembly

Substrate layers with individual bumps and cavities are provided which can be manufactured and tested in parallel and then joined into a multilayer substrate. The method of manufacturing these layers, as contemplated by the present invention, includes initially forming a plurality of vias in a layer of electrically conductive material. Next, a dielectric material, is placed adjacent the layer of conductive material. Holes which are coaxial with the vias are then formed in the dielectric material. Electrically conductive material is then deposited within the vias, thereby forming a conductive stud. Additional electrically conductive material is then deposited, on the side of the dielectric opposite the conductive material to form a signal layer, as well projections of electrically conductive material extending from the studs. A continuous layer of dielectric material is then placed adjacent the side of the substrate opposite the projections. A portion of this layer, adjacent the stud, is then removed, thereby exposing the stud and forming a cavity. The substrate layers can then be joined to form a multilayer substrate module.

Manufacturing process of a high density substrate design

A method and apparatus is provided for testing integrated circuits and permanently affixing the ICs which are successfully tested to a product level carrier substrate. A modular test oven is used which allows the chips to be electrically and thermally tested with the chips non-permanently affixed to a carrier substrate. If all of the chips on the carrier substrate test good, then the temperature within the oven is elevated, thereby reflowing the solder balls and permanently affixing the chips to the carrier substrate. This card can then be used in the manufacture of an electronic device without the necessity of reworking the burned-in ICs. Further, if any of the chips fail the burn-in testing, the time and overhead required for reworking is minimized since the chips are not permanently attached.

Modular test oven

A system is provided which utilizes a plurality of sequentially controlled magnetic repulsion punches arranged in a variable array to punch a constantly moving substrate. These punches are disposed adjacent the constant velocity substrate on which holes, or vias are formed as the punches are sequentially fired. The array of punches is placed at an angle with respect to the perpendicular of the direction of movement of the substrate. Thus, a delay is present between the time when the first punch must be fired and the firing of subsequent punches, due to the angle of the array. Therefore, due to this delay between the time the first punch must energized, and the energizing of subsequent punches a single power supply is capable of providing energy to a group of punches. Further, with the system of the present invention, it is possible to punch rows of holes lying in straight rows perpendicular to the direction of movement of the substrate and have different center to center distances on the same substrate, without the necessity of rearranging the array of punches and performing an additional punching operation.

Variable array punch

A multi-level circuit structure is provided which includes a plurality of overlying substrates, each having at least one conductive core. A plurality of imprinted depressions are formed in each substrate, each depression having a convex surface and a concave surface. Dielectric coatings are utilized to provide insulation between adjacent substrates and by selectively placing a conductive mass between selected overlying imprinted depressions an electrical connection may be formed between adjacent imprinted depressions wherein selected portions of one substrate may be electrically coupled to selected portions of a second substrate.

Multi-level circuit structure utilizing conductive cores having

A multilayer, flexible substrate upon which integrated circuit chips can be attached is disclosed. The input/output(I/O) connections from the chip do not radiate outward from the side of the die, but rather extend from a bottom surface. Since the I/O signal lines would not be accessible for testing once the IC chip is mounted on a substrate, each I/O line is extended outward from the IC footprint to an area on the substrate which is accessible. Additionally, an electrical path from each I/O signal port is simultaneously passed through the substrate layers upon which the chip is mounted, thus providing electrical contact of all I/O ports to the underside of the flexible substrate. An integrated circuit chip is mounted on this flexible substrate. Since each I/O line is accessible after mounting, the IC chip can be tested prior to mounting on its ultimate carrier. Once tested, the IC chip and the substrate upon which it is mounted are excised from the roll of substrate material. This excised, pretested memory package, which includes both the IC chip and the flexible substrate, can then be mounted directly onto the ultimate carrier either by reflow soldering or direct bonding.

Integrated circuit packaging using flexible substrate

An electronic circuit packaging module includes a lower substrate, an upper cooling unit, and a frame disposed between the substrate and cooling unit. The substrate carries a plurality of integrated circuit chips with lead-outs to a plurality of downwardly protruding dimpled contact points disposed about the substrate periphery. The frame includes a plurality of insulative inserts about its periphery having conductive pins each with a lower extension extending below the insert and an upper contact point recessed within the insert. The cooling unit includes a plurality of fluid bags each in contact with a respective chip on the substrate for thermal management. A plurality of such modules are stacked in vertical registry with each downwardly protruding dimple of a module extending into a respective insert recess of an adjacent module. Electrical contact is thus effected between the respective dimples on the lower surface of the upper module and respective upper contact points of the recessed pins on the upper surface of the cover module. The lower extension of the pins of each insert of a given module thus extend into contact with the upper surface of a respective dimple of an adjacent lower module. In this manner, vertical electrical interconnection is established through the pins when mated in vertical registry, establishing a plurality of conductive paths in the Z axis.

Modular electronic packaging system

An interconnect strip is provided for effecting electrical interconnection between pluralities of conductor pads disposed on circuit boards or the like in a high density configuration. The strip is fabricated from a polymer film carrier having laminated thereon a metal foil with preselected spring properties. After lamination, lithographic techniques from a series of electrically isolated metallic beams on the carrier. Additional chemical processing removes portions of the carrier at opposing sides of the strip to expose opposing ends of the beams which extend beyond the carrier parallel to one another in opposing directions outwards from the carrier. By urging the pads towards respective beam ends of the strip disposed between the pads until mating engagement therewith, a plurality of electrical interconnections are established through the beams. Flexural properties of the strip provide a low insertion force connection for a high density of conductors wherein the spring action of the strip assures favorable contact forces to the pads. The exposed film side of the strip may also be metalized and provided with beams or interconnected to beams on opposing side of the film by vias thereby providing a ground plane.

High density interconnect strip

A heat sink for utilization in thermal management of high density integrated circuit substrates is disclosed. Each heat sink includes at least one compliant bag containing a mass of thermally conductive fluid. Within each compliant bag is an aperture which contains a thin pliable metallic membrane having a high Z axis thermal conductivity. The metallic membrane is adapted to slidably mate with a surface of an integrated circuit device to permit relative motion during thermal mismatch while enhancing thermal conductivity from the integrated circuit device into the thermally conductive fluid. A second metallic membrane is preferably mounted to the upper surface of the compliant bag and is thermally coupled to a plurality of cooling fins. In one embodiment of the present invention, a plurality of such compliant bags are serially interconnected and a pump is utilized to circulate fluid through each compliant bag. In this embodiment, a pair of rigidly mounted needle valves may be utilized to automatically couple the fluid pump to the plurality of compliant bags in response to the electrical connection of a substrate incorporating such a heat sink.

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Austin, TX, United States of America

Karl Hermann