# US 4,396,666 A · Solderable conductive employing an organic binder > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,396,666 A - Document ID: US4396666A - Status: Granted - Kind: A - Application number: 06/317,235 - Filed: 1981-11-02 - Granted: 1983-08-02 - Earliest claimed: 1981-11-02 - Assignees: CTS Corporation - Inventors: Craig N. Ernsberger - Web page: https://patentgrep.com/patent/US4396666A ## CPC - H05K 3/1283: {After-treatment of the printed patterns, e.g. sintering or curing methods} - C09D 163/00: Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins - C09J 5/02: involving pretreatment of the surfaces to be joined - H01B 1/22: the conductive material comprising metals or alloys - H05K 3/245: {Reinforcing conductive patterns made by printing techniques or by other techniques for applying conductive pastes, inks or powders; Reinforcing other conductive patterns by such techniques} - H05K 2203/1105: Heating or thermal processing not related to soldering, firing, curing or laminating, e.g. for shaping the substrate or during finish plating - Y10S 428/901: Printed circuit - Y10T 428/12049: Nonmetal component - Y10T 428/24909: Free metal or mineral containing - Y10T 428/24917: including metal layer - Y10T 428/24926: including ceramic, glass, porcelain or quartz layer - Y10T 428/256: Heavy metal or aluminum or compound thereof - Y10T 428/31: Surface property or characteristic of web, sheet or block - Y10T 428/31511: Of epoxy ether - Y10T 428/31525: Next to glass or quartz - Y10T 428/31529: Next to metal - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) - C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H) - H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K}) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A conductive layer (13) adhesively joined to an electrically inert substrate (10) by an organic binder component. The organic binder consists of a resin not substantially less than 15% nor more than about 35% by weight of the composition which further includes dispersed metallic material within the binder and forming the electrically conductive component of the solderable material. A solderable surface layer (15) of the conductive layer (13) includes exposed metallic material suitable for solder bonding terminations (16) to the conductive layer (13), such solderable surface layer (15) being adhesively joined to the binder by means of the organic matrix. ## Claims ### Claim 1 A solderable conductive composition forming a conductive layer on a substrate and suitable for forming an adhesive bond with solder, comprising a solderable material including an organic, generally pyrolytically decomposed-at-the-surface-only cycloaliphatic epoxy binder and comprising not less than 15 percent and not more than 35 percent by weight of the composition forming said solderable material, a plurality of discrete metallic particles dispersed within said binder for forming an electrical connection between said conductive layer and solder, and a solderable surface layer of said conductive layer characterized by a continuous phase of metallic particles readily bondable with solder and said surface layer rigidly affixed to the subjacent material by said binder. ### Claim 2 (depends on 1) The composition of claim 1, wherein said binder is a thermosetting resin. ### Claim 3 (depends on 1) The composition in accordance with claim 1, in which said conductive layer is rigidly adhered to a substrate by said binder and said substrate comprises a plastic or ceramic substrate. ### Claim 4 (depends on 1) The composition in accordance with claim 1, in which said resistivity is less than 0.5 ohms/sq. ### Claim 5 (depends on 1) The composition in accordance with claim 1, in which the cure temperature is less than 300.degree. C. ### Claim 6 (depends on 1) The composition in accordance with claim 1, further comprising a substrate adhered to said conductive layer, said substrate selected from the group consisting of ceramic, plastic and quartz. ### Claim 7 (depends on 1) The composition in accordance with claim 1, further comprising a conductor joined by solder to said solderable surface layer to effect an electrical path between the conductive layer and said conductor. ### Claim 8 A method for producing a solderable conductive layer on a substrate, comprising the steps of (a) mixing together cycloaliphatic epoxy binder and particulate metallic materials which serve as the conductive component of said layer wherein said metallic materials comprise 65% to 85% by weight of said mixture, (b) selectively disposing such composition onto a substrate, with said binder providing the adhesive agent between said substrate and the composition, (c) curing said composition to a heat hardened condition which is both stable and substantially inert, and (d) pyrolytically decomposing a surface layer of said composition by effecting pyrolytic decomposition at the surface only of said composition to provide for solderable adhesion of an electrically conductive termination to said surface layer. ### Claim 9 (depends on 8) The process in accordance with claim 8, wherein said binder forms an adhesive bond between the solderable surface layer and the underlying composition. ### Claim 10 (depends on 8) The process in accordance with claim 8, including the step of forming a solder bond between a conductive termination and the conductive particles within said solderable surface layer to form an electrical connection between said conductive layer and termination. ### Claim 11 (depends on 8) The process in accordance with claim 8, wherein step (c) comprises a one step curing of the composition at a temperature of at least 50.degree. C. higher than the conventional curing temperature. ### Claim 12 (depends on 8) The process in accordance with claim 8, wherein step (c) and (d) comprise two steps consisting of an initial cure at the conventional curing temperature followed by a further cure consisting of heating at a further elevated temperature and time whereby the binder as a whole is not pyrolytically decomposed but the composition surface is decomposed to render it solderable. ### Claim 13 (depends on 8) An article constructed in accordance with claim 8, which is formed by said process and is characterized in that the surface layer is pyrolytically decomposed, and said article includes a solder bond between said surface layer and a termination selectively attached.