# US 11,993,704 B2 · Insulating medium rubber film and production method thereof and multi-layer printed-circuit board > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,993,704 B2 - Document ID: US11993704B2 - Status: Granted - Kind: B2 - Application number: 17/279,845 - Filed: 2019-09-19 - Published: 2022-02-03 - Granted: 2024-05-28 - Earliest claimed: 2019-09-05 - Assignees: Shenzhen Newfilms New Material Technology Co., Ltd - Applicants: Shenzhen Newfilms New Material Technology Co., Ltd - Inventors: Yueshan He; Fei Liu; Qiong He - Web page: https://patentgrep.com/patent/US11993704B2 ## CPC - C08L 63/00: Compositions of epoxy resins; Compositions of derivatives of epoxy resins - C08L 79/02: Polyamines - C09J 7/10: without carriers - C09J 163/00: Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins - H05K 1/0326: {containing O} - H05K 1/0373: {containing additives, e.g. fillers (H05K1/036 takes precedence)} - C08L 2203/206: use in coating or encapsulating of electronic parts - C08L 2205/035: containing four or more polymers in a blend - C09J 2203/326: for bonding electronic components such as wafers, chips or semiconductors - C09J 2301/408: additives as essential feature of the adhesive layer - C09J 2463/00: Presence of epoxy resin - C09J 2467/00: Presence of polyester - C09J 2467/005: in the release coating - C09J 2475/00: Presence of polyurethane - H05K 1/0298: {Multilayer circuits} - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - 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) - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract An insulating medium rubber film and a production method thereof, and a multi-layer printed-circuit board. The insulating medium rubber film includes a release film and an insulating medium layer arranged on the surface of the release film, where materials of the insulating medium layer include saturated polyester resin, amino resin or blocked isocyanate, epoxy resin, a curing agent, inorganic filler and a curing accelerator. According to the insulating medium rubber film and the production method thereof and the multi-layer printed-circuit board, by introducing the saturated polyester resin component into an epoxy resin composition, the produced insulating medium rubber film has the advantages that a dielectric constant is low, a dielectric dissipation factor is low, thermal expansion is not liable to happen, and adhesion is good. ## Claims ### Claim 1 An insulating medium rubber film, comprising: a release film and an insulating medium layer arranged on a surface of the release film, and a material of the insulating medium layer comprises saturated polyester resin, amino resin or blocked isocyanate, epoxy resin, curing agent, inorganic filler and curing accelerator; wherein the material of the insulating medium layer comprises, by weight, 5-30 units of saturated polyester resin, 0.5-3 units of amino resin or blocked isocyanate, 45-75 units of epoxy resin, 1-25 units of the curing agent, 1-100 units of the inorganic filler and 0.1-5 units of the curing accelerator; wherein a relative molecular weight of the saturated polyester resin is 8000-30000, and a chemical structural formula of the saturated polyester resin is: wherein n is 1-100, R1 and R2 are selected independently from the group consisting of alkyl groups, phenyl groups, naphthyl groups or combination groups thereof, all the functional groups have less than 20 carbon atoms; and wherein the saturated polyester resin does not contain a polar hydroxyl group in the middle of the saturated polyester resin and only contains a plurality of hydroxyl groups at an end of the saturated polyester resin. ### Claim 2 (depends on 1) The insulating medium rubber film according to claim 1, wherein the amino resin is a resin formed by a condensation polymerization of melamine or benzoquanmine, with formaldehyde and organic alcohol. ### Claim 3 (depends on 1) The insulating medium rubber film according to claim 1, wherein the blocked isocyanate is selected from the group consisting of phenol-blocked hexamethylenene diisocyanate (HDI), diphenyl-methane-diisocyanate (MDI), toluene diisocyanate (TDI), and phorone diisocyanate (PDI); or, the blocked isocyanate is selected from the group consisting of a caprolactam-blocked HDI, MDI, TDI and PDI. ### Claim 4 (depends on 1) The insulating medium rubber film according to claim 1, wherein the epoxy resin is selected from the group consisting of bisphenol A epoxy resin, bisphenol F epoxy resin, dicyclopentadiene (DCPD) epoxy resin, triphenol epoxy resin, biphenyl epoxy resin, naphthol epoxy resin and phosphorus-containing epoxy resin. ### Claim 5 (depends on 1) The insulating medium rubber film according to claim 1, wherein the curing agent is selected from the group consisting of dicyandiamide, aromatic amine, phenolic compounds, active grease, and phosphorus-containing phenolic aldehyde. ### Claim 6 (depends on 1) The insulating medium rubber film according to claim 1, wherein a thickness of the release film is 10-100 μm, and a thickness of the insulating medium layer is 10-200 μm. ### Claim 7 A production method for the insulating medium rubber film comprising a release film and an insulating medium layer arranged on a surface of the release film, a material of the insulating medium layer comprising saturated polyester resin, amino resin or blocked isocyanate, epoxy resin, curing agent, inorganic filler and curing accelerator, the method comprising: adding and mixing amino resin or blocked isocyanate to a solution of saturated polyester resin to prepare a first rubber solution; adding and mixing epoxy resin and curing agent to the first rubber solution to prepare a second rubber solution; adding and mixing inorganic filler and curing accelerator to the second rubber solution to prepare a third rubber solution; and coating and curing the third rubber solution on the release film to obtain the insulating medium rubber film; wherein the material of the insulating medium layer comprises, by weight, 5-30 units of saturated polyester resin, 0.5-3 units of amino resin or blocked isocyanate, 45-75 units of epoxy resin, 1-25 units of the curing agent, 1-100 units of the inorganic filler and 0.1-5 units of the curing accelerator; wherein a relative molecular weight of the saturated polyester resin is 8000-30000, and a chemical structural formula of the saturated polyester resin is: wherein n is 1-100, R1 and R2 are selected independently from the group consisting of alkyl groups, phenyl groups, naphthyl groups or combination groups thereof, all the functional groups have less than 20 carbon atoms; and wherein the saturated polyester resin does not contain a polar hydroxyl group in the middle of the saturated polyester resin and only contains a plurality of hydroxyl groups at an end of the saturated polyester resin. ### Claim 8 A multi-layer printed-circuit board, the multi-layer printed-circuit board comprising an insulating medium rubber film that comprises: a release film and an insulating medium layer arranged on a surface of the release film, a material of the insulating medium layer comprises saturated polyester resin, amino resin or blocked isocyanate, epoxy resin, curing agent, inorganic filler and curing accelerator; wherein the material of the insulating medium layer comprises, by weight, 5-30 units of saturated polyester resin, 0.5-3 units of amino resin or blocked isocyanate, 45-75 units of epoxy resin, 1-25 units of the curing agent, 1-100 units of the inorganic filler and 0.1-5 units of the curing accelerator; wherein a relative molecular weight of the saturated polyester resin is 8000-30000, and a chemical structural formula of the saturated polyester resin is: wherein n is 1-100, R1 and R2 are selected independently from the group consisting of alkyl groups, phenyl groups, naphthyl groups or combination groups thereof, all the functional groups have less than 20 carbon atoms; and wherein the saturated polyester resin does not contain a polar hydroxyl group in the middle of the saturated polyester resin and only contains a plurality of hydroxyl groups at an end of the saturated polyester resin. ### Claim 9 (depends on 8) The multi-layer printed-circuit board according to claim 8, wherein the amino resin is a resin formed by a condensation polymerization of melamine or benzoquanmine, with formaldehyde and organic alcohol. ### Claim 10 (depends on 8) The multi-layer printed-circuit board according to claim 8, wherein the blocked isocyanate is selected from the group consisting of phenol-blocked hexamethylenene diisocyanate (HDI), diphenyl-methane-diisocyanate (MDI), toluene diisocyanate (TDI), and phorone diisocyanate (PDI); or, the blocked isocyanate is selected from the group consisting of a caprolactam-blocked HDI, MDI, TDI and PDI. ### Claim 11 (depends on 8) The multi-layer printed-circuit board according to claim 8, wherein the epoxy resin is selected from the group consisting of bisphenol A epoxy resin, bisphenol F epoxy resin, dicyclopentadiene (DCPD) epoxy resin, triphenol epoxy resin, biphenyl epoxy resin, naphthol epoxy resin and phosphorus-containing epoxy resin. ### Claim 12 (depends on 8) The multi-layer printed-circuit board according to claim 8, wherein the curing agent is selected from the group consisting of dicyandiamide, aromatic amine, phenolic compounds, active grease, and phosphorus-containing phenolic aldehyde. ### Claim 13 (depends on 8) The multi-layer printed-circuit board according to claim 8, wherein a thickness of the release film is 10-100 μm, and a thickness of the insulating medium layer is 10-200 μm.