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CN-121989519-A - Treated copper foil, laminate, and method for producing same

CN121989519ACN 121989519 ACN121989519 ACN 121989519ACN-121989519-A

Abstract

The invention provides a treated copper foil which can be firmly adhered to a substrate at a smooth interface with small irregularities. The present invention also provides a laminate in which a base material and a treated copper foil are firmly bonded to each other at a smooth interface with small irregularities, and a method for producing the laminate. It was found that by using a treated copper foil in which a conductive layer (B) containing silver (B1) is laminated on a copper foil (a) having small irregularities, the copper foil (a) and a base material (D) can be firmly bonded at a smooth interface having small irregularities, and the present invention has been completed.

Inventors

  • FURUYA YOSHITAKE
  • Tian Cunli
  • FUKAZAWA NORIMASA
  • FUJIKAWA WATARU

Assignees

  • DIC株式会社

Dates

Publication Date
20260508
Application Date
20251022
Priority Date
20241107

Claims (20)

  1. 1. A treated copper foil is provided, wherein a conductive layer (B) containing silver (B1) is laminated on at least one surface of a copper foil (A).
  2. 2. The treated copper foil according to claim 1, wherein the conductive layer (B) further contains a dispersant (B2).
  3. 3. The treated copper foil according to claim 2, wherein the dispersant (b 2) has a basic nitrogen atom-containing group.
  4. 4. The treated copper foil according to claim 1 to 3, wherein the conductive layer (B) containing silver (B1) has a surface resistivity of 0.01Ω/≡3.00Ω/≡or more.
  5. 5. A treated copper foil according to claim 1 to 3, wherein the silver (B1) forming the conductive layer (B) is particles having a particle diameter of 30 to nm to 1000 nm, wherein the particles have a volume fraction of 50% or more by a small angle X-ray scattering method.
  6. 6. The treated copper foil according to claim 1 to 3, wherein the conductive layer (B) has a conductivity of not less than 2.0X10 7 S/m and not more than 6.0X10 7 S/m at 15.6 GHz and a conductivity of not less than 1.3X10 7 S/m and not more than 5.5X10 7 S/m at 54.5 GHz as measured by a balanced disk resonator method.
  7. 7. A treated copper foil according to claim 1 to 3, wherein the surface roughness Sz of the side surface of the conductive layer (B) in the copper foil (A) on which the conductive layer (B) is laminated is 0.1 μm or more and 2.0 μm or less.
  8. 8. The treated copper foil according to claim 1 to 3, wherein the conductive layer (B) is formed in a weight of 300 mg/m 2 or more and 10,000 mg/m 2 or less.
  9. 9. A treated copper foil according to claim 1 to 3, wherein a resin layer (C) is further laminated on the conductive layer (B).
  10. 10. The treated copper foil according to claim 9, wherein the resin layer (C) is a resin layer (C) containing a compound (C1) having a functional group [ X ].
  11. 11. The treated copper foil according to claim 10, wherein the functional group [ X ] is at least one functional group selected from the group consisting of an epoxy group, a carboxylic acid anhydride group, a ketone group, an alkanolamide group, an isocyanate group, a vinyl group, a halogenated alkyl group, an acryl group, a cyanamide group, a carbonamide group and a halogenated acyl group.
  12. 12. The treated copper foil according to claim 9, wherein the thickness of the resin layer (C) is 0.01 μm or more and 10 μm or less.
  13. 13. A laminate comprising the treated copper foil according to claim 1, wherein the conductive layer (B) side of the treated copper foil is in contact with at least one surface of the substrate (D).
  14. 14. A laminate comprising the treated copper foil according to claim 9, wherein the resin layer (C) side of the treated copper foil is laminated so as to be in contact with at least one surface of the base material (D).
  15. 15. The laminate according to claim 13, wherein the substrate (D) is an insulating resin substrate.
  16. 16. The laminate according to claim 14, wherein the substrate (D) is an insulating resin substrate.
  17. 17. The laminate according to claim 13, wherein the treated copper foil of the laminate obtained by the method specified in Japanese Industrial Standard C6481 has a peel strength of 0.4 kN/m or more.
  18. 18. The laminate according to claim 14, wherein the treated copper foil of the laminate obtained by the method specified in Japanese Industrial Standard C6481 has a peel strength of 0.4 kN/m or more.
  19. 19. The laminate according to claim 13, wherein, in the laminate, when the copper foil (A) is removed, the surface resistivity of the conductive layer (B) on the removal side surface of the copper foil (A) is 0.01Ω/≡or more and 3.00Ω/≡or less.
  20. 20. The laminate according to claim 14, wherein, in the laminate, when the copper foil (A) is removed, the surface resistivity of the conductive layer (B) on the removal side surface of the copper foil (A) is 0.01Ω/≡or more and 3.00Ω/≡or less.

Description

Treated copper foil, laminate, and method for producing same Technical Field The present invention relates to a treated copper foil and a method for producing the same. More specifically, the present invention relates to a treated copper foil which can be firmly bonded to a substrate at a smooth interface with small irregularities, and a method for producing the treated copper foil. Further, the present invention relates to a laminate in which a base material and a treated copper foil are firmly bonded to each other at a smooth interface with small irregularities, and a method for producing the laminate. Background With the miniaturization and high speed of electronic devices, there is a demand for higher density and higher performance of semiconductor package substrates and printed wiring boards, and in order to meet the demand, there is a demand for semiconductor package substrates and printed wiring boards having a metal layer with a smooth surface. As a laminate constituting a printed wiring board, a flexible copper clad laminate (hereinafter, abbreviated as "FCCL") or a rigid copper clad laminate (rigid copper CLAD LAMINATE) (hereinafter, abbreviated as "RCCL") is known. The FCCL is mainly produced by a method of bonding a heat-resistant polymer film to a copper foil with an epoxy resin adhesive, a method of forming a film by applying a varnish such as polyimide on the surface of the copper foil and drying the same (casting method), and a method of thermocompression bonding the copper foil and a polyimide film having a thermoplastic resin layer (lamination method). The RCCL is produced by a method of bonding a completely cured resin or ceramic to a copper foil with an epoxy resin-based adhesive, a method of bonding a semi-cured base material (prepreg) to a copper foil by heating a glass cloth impregnated with an epoxy resin, and a method of applying a varnish in which a resin and an inorganic filler are mixed to a release film, drying the film, and bonding a resin film obtained after drying to a surface of a copper foil or copper wiring by thermocompression bonding (deposition film). In general, FCCL or RCCL is a technology in which roughness is provided at the interface between a copper foil and a base material, and the copper foil is brought into close contact with the base material by an anchor effect (for example, see patent document 1, patent document 2, and patent document 3). In the fifth generation mobile communication system (fifth G) which is now in widespread use, or Beyond 5G (Beyond 5G) which is expected to expand in the future, it is necessary to reduce the transmission loss of high frequency signals. Transmission loss occurs due to resistance (dielectric loss) caused by dielectric characteristics of the substrate and resistance (conductor loss) caused by surface roughness of the conductor (copper wiring). When the dielectric constant or the dielectric loss tangent of the substrate itself is high, a part of energy is lost as heat in the dielectric body when a high-frequency alternating current flows. In order to reduce the dielectric loss, it is necessary to design a molecule such that the polar functional groups contained in the base material are reduced to reduce the movement of the polymer molecular chain. However, such a polymer having a molecular design has a problem that the adhesion between the substrate and the copper foil is reduced. When a high-frequency current flows through the conductor, the conductor loss is a phenomenon in which an electric signal is scattered by irregularities (roughened portions) present on the surface of the conductor (copper wiring) and is lost as heat. In order to reduce the conductor loss, it is necessary to reduce the surface roughness of the surface of the conductor (copper foil), but in the conventional method of bonding the copper foil to the substrate by the anchor effect, there is a problem that the smaller the surface roughness of the surface of the copper foil, the lower the bonding force of the substrate to the copper foil. Therefore, in the future, in a semiconductor package substrate or a printed wiring board in which transmission loss is required to be reduced, as described above, a substrate having a low dielectric constant and a low dielectric loss tangent, which is disadvantageous from the viewpoint of adhesion to a copper foil, is required to form a conductor (copper wiring) at an interface which is as smooth as possible, and thus a new copper foil is required. [ Prior Art literature ] [ Patent literature ] Patent document 1 Japanese patent laid-open No. 2003-69218 [ Patent document 2] Japanese patent laid-open No. 2003-249751 [ Patent document 3] Japanese patent 5524833 Disclosure of Invention [ Problem to be solved by the invention ] The invention provides a treated copper foil which can be firmly adhered to a substrate at a smooth interface with small irregularities, and a method for producing the same. Further, a laminate in which