# US 2013/0153138 A1 · Method of manufacturing reuse paste, reuse paste and method of manufacturing circuit board using reuse paste > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153138 A1 - Document ID: US20130153138A1 - Status: Published application - Kind: A1 - Application number: 13/817,733 - Filed: 2012-07-24 - Published: 2013-06-20 - Earliest claimed: 2011-07-27 - Assignees: Panasonic Corporation - Inventors: Tsuyoshi Himori; Masaaki Katsumata; Toshikazu Kondou - Web page: https://patentgrep.com/patent/US20130153138A1 ## CPC - H05K 3/0094: {Filling or covering plated through-holes or blind plated vias, e.g. for masking or for mechanical reinforcement} - H01B 1/20: Conductive material dispersed in non-conductive organic material {(organic macromolecular compounds or compositions C08)} - H01B 1/22: the conductive material comprising metals or alloys - H05K 3/4069: {for via connections in organic insulating substrates} - H05K 1/092: {Dispersed materials, e.g. conductive pastes or inks} - H05K 3/4652: {Adding a circuit layer by laminating a metal foil or a preformed metal foil pattern (H05K3/4647 takes precedence)} - H05K 2203/178: Demolishing, e.g. recycling, reverse engineering, destroying for security purposes; Using biodegradable materials - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - 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}) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A method of manufacturing a reuse paste includes preparing a fiber piece housing paste, producing a filtered recovery paste, and producing a reuse paste. In the preparing of the fiber piece housing paste, a conductive paste including a conductive particle, resin and a latent curing agent, and a fiber piece housing paste including a fiber piece dropping off from a prepreg used for manufacturing a circuit board are prepared. In the producing of the filtered recovery paste, the filtered recovery paste is produced by filtering the fiber piece housing paste, which remains in a paste state, by using a filter. In the production of the reuse paste, the reuse paste is produced by adding at least one of a solvent, resin, and a paste having a different composition from that of the filtered recovery paste into the filtered recovery paste. ## Claims ### Claim 1 A method of manufacturing a reuse paste, the method comprising: preparing a fiber piece housing paste that includes a conductive paste including a conductive particle, resin and a latent curing agent, and a fiber piece dropping off from a prepreg used for manufacturing a circuit board; producing a filtered recovery paste by filtering the fiber piece housing paste, which remains in a paste state, by using a filter; and producing a reuse paste by adding at least one of a solvent, resin, and a paste having a different composition from that of the filtered recovery paste into the filtered recovery paste. ### Claim 2 (depends on 1) The method of manufacturing a reuse paste of claim 1, wherein the latent curing agent has a softening temperature of not less than 80° C. and not more than 180° C. ### Claim 3 (depends on 1) The method of manufacturing a reuse paste of claim 1, wherein the latent curing agent has a particle diameter of not less than 0.5 μm and not more than 30 μm. ### Claim 4 (depends on 1) The method of manufacturing a reuse paste of claim 1, wherein the latent curing agent is a solid from the preparing of the fiber piece housing paste to the producing of the reuse paste. ### Claim 5 (depends on 1) The method of manufacturing a reuse paste of claim 1, wherein the latent curing agent is at least one of an amine-based latent curing agent, an amine adduct-based latent curing agent, a hydrazide-based latent curing agent, an imidazole-based latent curing agent, and a dicyandiamide-based latent curing agent. ### Claim 6 (depends on 1) The method of manufacturing a reuse paste of claim 1, wherein an opening diameter of the filter is not less than three times as large as an average particle diameter of the conductive particles, not more than 20 times as large as an average particle diameter of the fiber pieces, and not less than two times as large as a diameter of the latent curing agent. ### Claim 7 A reuse paste obtained by a method of manufacturing a reuse paste, wherein the method comprises: preparing a fiber piece housing paste that includes a conductive paste including a conductive particle, resin and a latent curing agent, and a fiber piece dropping off from a prepreg used for manufacturing a circuit board; producing a filtered recovery paste by filtering the fiber piece housing paste, which remains in a paste state, by using a filter; and producing reuse paste by adding at least one of a solvent, resin, and a paste having a different composition from that of the filtered recovery paste into the filtered recovery paste. ### Claim 8 A method of manufacturing a circuit board, the method comprising: attaching a first protective film to a surface of a first prepreg; forming a first hole in the first prepreg through the first protective film; applying a conductive paste including a conductive particle, resin and a latent curing agent onto the first protective film; filling a part of the conductive paste into the first hole; gathering a plurality of the conductive pastes which have not been filled into the first hole for recovering them as a fiber piece housing paste; producing a filtered recovery paste by filtering the fiber piece housing paste, which remains in a paste state, by using a filter; producing a reuse paste by adding at least one of a solvent, resin, and a paste having a different composition from that of the filtered recovery paste into the filtered recovery paste; attaching a second protective film to a surface of a second prepreg; forming a second hole in the second prepreg through the second protective film; filling the reuse paste into the second hole; peeling the second protective film so as to form a protruded portion made of the reuse paste on the surface of the second prepreg; disposing a metal foil on both surfaces of the second prepreg, and pressurizing the second prepreg from outside of the metal foil; curing the second prepreg and the reuse paste by heating the second prepreg; and processing the metal foil into a wiring pattern. ### Claim 9 (depends on 8) The method of manufacturing a circuit board of claim 8, wherein the latent curing agent has a softening temperature of not less than 80° C. and not more than 180° C. ### Claim 10 (depends on 8) The method of manufacturing a circuit board of claim 8, wherein the latent curing agent has a particle diameter of not less than 0.5 μm and not more than 30 μm. ### Claim 11 (depends on 8) The method of manufacturing a circuit board of claim 8, wherein the latent curing agent is a solid at least from the applying of the conductive paste to the producing of the reuse paste. ### Claim 12 (depends on 8) The method of manufacturing a circuit board of claim 8, wherein the latent curing agent is at least one of an amine-based latent curing agent, an amine adduct-based latent curing agent, a hydrazide-based latent curing agent, an imidazole-based latent curing agent, and a dicyandiamide-based latent curing agent. ### Claim 13 (depends on 8) The method of manufacturing a circuit board of claim 8, wherein an opening diameter of the filter is not less than three times as large as an average particle diameter of the conductive particles, not more than 20 times as large as an average particle diameter of the fiber pieces, and not less than two times as large as a diameter of the latent curing agent. ### Claim 14 A method of manufacturing a circuit board, the method comprising: preparing a fiber piece housing paste including a conductive paste that includes a conductive particle, resin, and a latent curing agent, and a fiber piece dropping off from a first prepreg; producing a filtered recovery paste by filtering the fiber piece housing paste, which remains in a paste state, by using a filter; producing a reuse paste by adding at least one of a solvent, resin, and a paste having a different composition from that of the filtered recovery paste into the filtered recovery paste; attaching a second protective film to a surface of a second prepreg; forming a second hole in the second prepreg through the second protective film; filling the reuse paste into the second hole; peeling the second protective film so as to form a protruded portion made of the reuse paste on the surface of the second prepreg; disposing a metal foil on both surfaces of the second prepreg, and pressurizing the second prepreg from outside of the metal foil; curing the second prepreg and the reuse paste by heating the second prepreg; and processing the metal foil into a wiring pattern. ### Claim 15 (depends on 14) The method of manufacturing a circuit board of claim 14, wherein the latent curing agent has a softening temperature of not less than 80° C. and not more than 180° C. ### Claim 16 (depends on 14) The method of manufacturing a circuit board of claim 14, wherein the latent curing agent has a particle diameter of not less than 0.5 μm and not more than 30 μm. ### Claim 17 (depends on 14) The method of manufacturing a circuit board of claim 14, wherein the latent curing agent is a solid at least from the preparing of the conductive paste to the producing of the reuse paste. ### Claim 18 (depends on 14) The method of manufacturing a circuit board of claim 14, wherein the latent curing agent is at least one of an amine-based latent curing agent, an amine adduct-based latent curing agent, a hydrazide-based latent curing agent, an imidazole-based latent curing agent, and a dicyandiamide-based latent curing agent. ### Claim 19 (depends on 14) The method of manufacturing a circuit board of claim 14, wherein an opening diameter of the filter is not less than three times as large as an average particle diameter of the conductive particles, not more than 20 times as large as an average particle diameter of the fiber pieces, and not less than two times as large as a diameter of the latent curing agent.