Abstract: A flex or TAB product suitable for chip carrier applications wherein the flex reliability problems caused by copper dendrite growth and lead bending during power and thermal cycling are reduced by application of special coatings to lead areas of the flex tape.

Abstract: Certain organic polymeric materials are capable of reversibly accepting or donating electrons from a reducing entity. The redox sites in the polymer accept electrons and, as a result, a change in the properties of the polymer occurs. This change is useful in modifying or etching the polymeric material. The material can be modified by incorporation of metallic seeds into the material at a controlled depth. The seeds are incorporated by interaction of cations of the metals with the redox sites in the polymer, which cause the reduction of the cations to form the neutral metallic seeds. Subsequent exposure of the polymeric material containing the seeds to an electroless bath causes further deposition of metal having the desirable characteristic of good adhesion to the polymeric material. Etching of the polymeric material can be carried out as a result of an increase in solubility of the polymer in aprotic solvents when its redox sites have accepted electrons.

Abstract: A multi-chip module having very high density interconnect structures and a technique for making it, where all of the chips have their active device surfaces in a common plane. The chips are placed face down on an adjacent adhesive layer located on a substrate, which is preferably a flexible material. A conformal material is deposited over the backsides of the chips and in the spaces between the chips. A ground plane or metallic shield can then be formed over the conformal layer, if desired. The structure is then turned over and the glass layer on which the substrate is located is removed. Access vias are made through the substrate to the chip I/O's, and metallization provided to the chips. Interconnect metallization is then provided to complete the multi-chip module. In one embodiment, the substrate on which the chips are first supported is the first level of insulation above the active device surfaces of the chips and also ensures that the active device surfaces are in a common plane.

Abstract: The present invention relates to an improved flex (or TAB) product suitable for silicon carrier or other types of chip carrier applications, wherein the flex reliability problems caused for example by Cu thermal cycling are substantially reduced or eliminated. More particularly, the invention embodies a number of coatings for use in such products and diverse methods of making and using same.

Abstract: A protection configuration for a semiconductor ridge waveguide laser structure is disclosed wherein layers of protective metal in the form of walls, is applied on each side of the ridge element of the ridged layer of the laser structure. The laser structure is then bonded to a mounting plate in a junction side down orientation by solder or a junction side up orientation by wire bonding. The metal layer may be composed of gold.

Abstract: Disclosed is a reworkable circuit .package formed by controlled collapse chip connection ("C4") bonding of integrated circuit chips to circuit cards and boards, and direct chip attachment ("DCA") where an encapsulant is disposed under the chip. The encapsulant offers protection of the C4 connections and a thermal expansion matched to that of the C4 joints. However, most encapsulants interfere with reworkability. The disclosed circuit package overcomes this problem by the provision of a passivating layer of Parylene is reworkable, dry processable, uniformly depositable by vapor phase deposition, forming thin films on facing surfaces at the 3-5 micron film thickness corresponding to the C4 lift-off distance.

Abstract: Certain organic polymeric materials are capable of reversibly accepting or donating electrons from a reducing entity. The redox sites in the polymer accept electrons and, as a result, a change in the properties of the polymer occurs. This change is useful in modifying or etching the polymeric material The material can be modified by incorporation of metallic seeds into the material at a controlled depth. The seeds are incorporated by interaction of cations of the metals with the redox sites in the polymer, which cause the reduction of the cations to form the neutral metallic seeds. Subsequent exposure of the polymeric material containing the seeds to an electroless bath causes further deposition of metal having the desirable characteristic of good adhesion to the polymeric material. Etching of the polymeric material can be carried out as a result of an increase in solubility of the polymer in aprotic solvents when its redox sites have accepted electrons.

Abstract: The present invention comprises the use of a copper/nickel containing alloy composition or application of a protective nickel alloy coating to copper current-carrying leads to prevent electrolytic migration between tape automated bonding (TAB) package leads.

Abstract: Methods and apparatus are set forth for passively and precisely aligning pairs of objects, in particular, microelectronic components such as semiconductor lasers and fibers, utilizing fiducial marks. Additionally, methods and apparatus are set forth for combining passive and active alignment techniques where high degrees of alignment precision are required. Still further, techniques are described for fixing prealigned objects, independent of how the objects are prealigned, to a mounting surface in a manner that maintains the relative (aligned) position of the objects. Further yet, in order to help minimize manufacturing costs with respect to production of, for example, microelectronic assemblies, batch processing techniques are described which utilize the novel alignment procedures contemplated by the invention.

Abstract: The present invention comprises the use of a copper/nickel containing alloy composition or application of a protective nickel alloy coating to copper current-carrying leads to prevent electrolytic migration between tape automated bonding (TAB) package leads.

Abstract: A heat exchanger for cooling an array of electric circuit chips disposed on a common substrate is formed as a flexible sheet of thermally conducting material with upstanding fins for transference of heat from the chips to a coolant flowing through the fins. Pin fins may be employed with air coolant. The sheet may be provided with corrugations set between sites of the chips for improved flexibility to accommodate individual orientations of the chips. The sheet is sufficiently large to cover an array of chips and is thermally joined, as by use of a thermally conductive grease, to the chips. The sheet hermetically seals the chips from contamination by the coolant. For liquid coolant, the heat exchanger may be fabricated of copper with a nickel coating, wherein the copper provides the heat conduction and the nickel protects the copper from a corrosive coolant such as water.

Abstract: The superior thermal conductivity of immersion cooling combined with the service convenience of conduction cooling is provided through the use of unitary thermal transfer replaceable units positioned beneath a refrigeration source. Each unit contains electronic devices in a thermal transfer fluid. The unit construction permits replaceability in service without exposing a central fluid reservoir or opening a refrigerator.

Abstract: A heat exchanger for cooling an array of electric circuit chips disposed on a common substrate is formed as a flexible sheet of thermally conducting material with understanding fins for transference of heat from the chips to a coolant flowing through the fins. Pin fins may be employed with air coolant. The sheet may be provided with corrugations set between sites of the chips for improved flexibility to accommodate individual orientations of the chips. The sheet is sufficiently large to cover an array of chips and is thermally joined, as by use of a thermally conductive grease, to the chips. The sheet hermetically seals the chips from contamination by the coolant. For liquid coolant, the heat exchanger may be fabricated of copper with a nickel coating, wherein the copper provides the heat conduction and the nickel protects the copper from a corrosive coolant such as water.

Abstract: This invention employs a carrier upon which a thin conductive film has been applied. The conductive film is of a metallic material which exhibits a surface energy such that it is not readily wetted by solder. A patterned mask is disposed on the conductive film, with the mask having openings which expose selected areas of the conductive film. Solder is deposited in the mask openings and is weakly adherent to the exposed areas of the conductive film. The carrier is then disposed over and in registration with conductive land areas of a circuit carrier, such that the solder in the mask openings is aligned with the land areas of the circuit carrier. Subsequently, the carrier and circuit land areas are brought into contact, heated, the solder bonded to the lands, and the carrier is lifted away for subsequent reuse.In another species of the invention, a thin film layer of solder is directly deposited on and weakly adherent to a flexible base layer.

Abstract: A manifold for conducting coolant to a set of heat exchangers mounted on individual electric circuit chips of a circuit module is formed of a solid body containing fluid passages terminating in apertures, the manifold being provided with a set of hollow flexible appendages connected to the apertures for conducting coolant to ports of the heat exchangers. The body is formed of two sections, one section having channels machined therein to serve as the fluid passages, and a second section having the apertures. The second section also is bounded by sidewalls which define a cavity. The appendages are formed by a lost wax molding operation wherein the wax is stored in the cavity, and milled to form a mold for the appendages.

Abstract: A heat exchanger for cooling an array of electric circuit chips disposed on a common substrate is formed as a flexible sheet of thermally conducting material with upstanding fins for transference of heat from the chips to a coolant flowing through the fins. The sheet may be provided with corrugations set between sites of the chips for improved flexibility to accommodate individual orientations of the chips. The sheet is sufficiently large to cover an array of chips and is secured adheringly, as by use of a thermally conductive grease, to the chips. The sheet hermetically seals the chips from contamination by the coolant. The heat exchanger may be fabricated of copper with a nickel coating, wherein the copper provides the heat conduction and the nickel protects the copper from a corrosive coolant such as water. The finned sheet may be efficiently fabricated by processes analogous to those used to make printed circuits.

Abstract: An electromagnetic printhead is fabricated with a common flux returning backplate and an array of writing elements extending from the common backplate. The writing elements consist of large pedestals and small pedestals. The placement of the large pedestals provides addressability resolution; the small pedestals provide imaging resolution. The large pedestals accept electromagnetic flux from addressing conductors and transfer the flux through the respectively related small pedestals to an image receptor. There are several fabrication techniques which are eased by the separation of addressability resolution and imaging resolution, primarily because the wide separation of the large pedestals required for the addressing conductors mandate relatively massive removal of material and thus suggest relatively low precision machining techniques. The imaging resolution requires both high spacial precision and accurate dimension control, normally achievable by relatively high precision techniques.

Abstract: A method for fluxlessly joining members having relatively low melting materials is provided. The members to be joined are exposed to ion beam radiation of sufficient intensity and a time sufficient to cause cleaning of the low melting materials after cooling. The members are then placed into juxtaposition with each other and again exposed to ion beam radiation of an intensity and for a time sufficient to cause reflow of the low melting materials which upon cooling joins said members.

Abstract: In electrical circuitry, and particularly superconducting circuitry including Josephson tunnelling devices, it is often necessary to provide solder contacts to electrical lines, where the electical lines would be destroyed if there were interdiffusion between the lines and the solder. To avoid this problem, a laterally extending metallic layer is used as a diffusion barrier between the solder land and the electrical line which can be a superconducting line. The diffusion barrier is comprised of a refractory metal which has a first portion electrically contacting the solder land and a second, laterally displaced portion, electrically contacting the electrical line. An insulating protective layer on the diffusion barrier layer separates the solder land and the electrical line.