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CN-121988609-A - Glue-coated rolled copper foil and manufacturing method thereof

CN121988609ACN 121988609 ACN121988609 ACN 121988609ACN-121988609-A

Abstract

The invention discloses a glue-coated rolled copper foil and a manufacturing method thereof. The glued rolled copper foil comprises a rolled copper foil base material and a functional adhesive layer compounded on one surface of the rolled copper foil base material. The rolled copper foil base material is prepared by cooperative control of multi-pass cold rolling, differential rolling and sectional annealing for inhibiting complete recrystallization, so that an elongated grain structure with continuous fibrosis distribution is formed in the rolling direction. The grain structure is beneficial to improving the load transmission mode under the action of bending or thermal stress after compounding, thereby being beneficial to improving the interface bonding stability between the functional adhesive layer and the rolled copper foil. The manufacturing method has clear process path, is suitable for industrial implementation, and is suitable for the fields of flexible circuits, high-speed cables, flexible shields and the like.

Inventors

  • SHEN XIAOXIA
  • SHEN GUOZHONG

Assignees

  • 杭州巨力绝缘材料有限公司

Dates

Publication Date
20260508
Application Date
20260319

Claims (20)

  1. 1. A rubberized rolled copper foil is characterized by comprising a rolled copper foil substrate and a functional adhesive layer compounded on one surface of the rolled copper foil substrate, wherein the rolled copper foil substrate is obtained through cooperative control of multi-pass cold rolling, differential rolling and sectional annealing, the total rolling reduction of the rolled copper foil substrate is not lower than 97%, differential rolling with the upper and lower working roll linear speed ratio of 1.05-1.30 is implemented in at least part of cold rolling passes, sectional annealing treatment is implemented after the accumulated rolling reduction reaches 30% -60%, the sectional annealing treatment meets the following judgment condition of 'inhibiting complete recrystallization', the recrystal volume fraction of the rolled copper foil substrate is not higher than 30%, preferably not higher than 15% after sectional annealing, the Vickers hardness reduction amplitude delta HV of the rolled copper foil substrate is 10-35 HV after sectional annealing relative to the rolled copper foil substrate before sectional annealing, the rolled copper foil substrate is in a continuous fiber-distributed elongated crystal grain structure in the rolling direction after the technological treatment, and the crystal grain aspect ratio AR is not less than 15.
  2. 2. The sized rolled copper foil according to claim 1, wherein the elongated grain structure of the continuous fiber distribution satisfies a criterion that not less than 5 fields of view are selected in the RD-ND cross-section EBSD or metallographic image, not less than 200 grains are counted per field of view, the area fraction of equiaxed recrystallized grains in the field of view is not more than 10%, and the elongated grain region of the continuous distribution is visible in the RD direction.
  3. 3. The sized rolled copper foil according to claim 1, wherein the aspect ratio AR of the crystal grains of the rolled copper foil substrate is not less than 15, preferably not less than 18.
  4. 4. The sized rolled copper foil according to any one of claims 1 to 3, wherein the rolled copper foil substrate has a rolled texture score Ftex≥65% and the rolled texture comprises one or more orientations of beta fibers.
  5. 5. The sized rolled copper foil according to claim 1 to 4, wherein the rolled copper foil substrate has a dislocation density ρ of 2X 101 4 -1×10¹ 5 m-2.
  6. 6. The sized rolled copper foil according to claim 1 to 5, wherein the volume fraction of recrystallization of the rolled copper foil substrate is not higher than 30%, preferably not higher than 15%.
  7. 7. The sized and calendered copper foil according to any one of claims 1 to 6, wherein the functional size layer is one or more of a polyester-based, an acrylic-based, a polyurethane-based, a rubber-modified thermoplastic, or a composite thereof.
  8. 8. The sized rolled copper foil according to any one of claims 1 to 7, wherein the functional adhesive layer is an adhesive layer capable of softening or melting during the compounding process and forming an adhesive interface after cooling.
  9. 9. The sized rolled copper foil according to any one of claims 1 to 8, wherein the functional adhesive layer is not subjected to a specific chemical coupling modification treatment for the copper surface prior to compounding with the rolled copper foil substrate.
  10. 10. The sized rolled copper foil according to any one of claims 1 to 9, wherein the rolled copper foil substrate has a micro-roughened surface on one side thereof in combination with a functional subbing layer.
  11. 11. A process for producing a rubberized rolled copper foil, characterized by comprising the steps of a) providing a copper blank, and subjecting the copper blank to a multi-pass cold rolling to gradually thin the copper foil, wherein the total reduction of cold rolling is not less than 97%, b) subjecting the copper blank to differential rolling during at least a part of the multi-pass cold rolling to a linear speed ratio of 1.05 to 1.30 between upper and lower working rolls, c) subjecting the copper foil to at least one step of sectional annealing treatment after the cumulative reduction reaches 30 to 60% during the multi-pass cold rolling, wherein the sectional annealing treatment satisfies the condition that the recrystallization volume fraction of the rolled copper foil is not more than 30%, preferably not more than 15%, after the sectional annealing, and the reduction of the Vickers hardness of the rolled copper foil is 10 to 35 HV relative to that before the sectional annealing, d) continuing cold rolling after the sectional annealing treatment, e) compositing a functional adhesive layer on one side of the rolled base material to obtain a rubberized rolled copper foil, wherein the rolled copper foil obtained by steps a) to d) has a continuous grain structure of the rolled base material in the direction of the length to AR, and the rolled copper foil has a continuous grain structure of 15% or more.
  12. 12. The method of producing a rubberized and calendered copper foil according to claim 11, wherein the linear velocity ratio of the upper and lower work rolls in said differential rolling is 1.10 to 1.20.
  13. 13. The method of producing a rubberized and calendered copper foil according to claim 11 or 12, wherein said differential rolling passes are 20% to 60% of the total cold rolling passes.
  14. 14. The method for producing a rubberized and calendered copper foil according to any one of claims 11 to 13, wherein said differential rolling is provided in the range of 30% to 50% of the rear section of the total reduction of cold rolling.
  15. 15. The method for producing a rubberized and calendered copper foil according to any one of claims 11 to 14, wherein said differential rolling is alternated with conventional symmetric rolling.
  16. 16. The method for producing a rubberized and calendered copper foil according to any one of claims 11 to 15, wherein said step annealing has an annealing temperature lower than a complete recrystallization temperature measured in advance under the same material composition, similar thickness and same holding time.
  17. 17. The method for producing a rubberized rolled copper foil according to any one of claims 11 to 16, wherein said step annealing treatment reduces the Vickers hardness of the rolled copper foil by an amount of from 10 to 35 HV as measured under the same conditions of load, holding time and sampling position.
  18. 18. The method for producing a rubberized, rolled copper foil according to any one of claims 11 to 17, wherein in step e), the functional adhesive layer is compounded on the surface of the rolled copper foil substrate by coating, hot press bonding or extrusion coating.
  19. 19. The method for producing a rubberized and calendered copper foil according to claim 18, wherein said functional adhesive layer is not subjected to a special chemical coupling modification treatment for the copper surface prior to compounding.
  20. 20. The method of producing a rubberized, calendered copper foil according to claim 18 or 19, wherein said functional adhesive layer softens or melts under heat and pressure and forms a bonded interface upon cooling.

Description

Glue-coated rolled copper foil and manufacturing method thereof Technical Field The invention relates to a glue-coated rolled copper foil and a manufacturing method thereof, in particular to a rolled copper foil substrate with a specific grain structure, which is obtained through differential rolling and segmented annealing cooperative control for inhibiting complete recrystallization, and a functional adhesive layer is compounded on the surface of the rolled copper foil substrate, so that a composite rolled copper foil with good interface bonding stability is obtained, and on the premise of not reducing the coating line speed and not increasing the thickness of the metal foil, how to inhibit crack initiation of the metal foil in a flanging and lap joint area in a high-speed coating process is realized. Background The rolled copper foil is widely applied to the fields of flexible circuits, flexible shielding layers, high-speed cables and the like due to the excellent ductility and fatigue resistance. In practical applications, the rolled copper foil is usually compounded with other functional layers or structural layers by gluing, so that the stability of the interface bonding between the copper foil and the adhesive layer becomes a key factor affecting the reliability of the product. In the prior art, in order to improve the bonding force between the adhesive layer and the copper foil, one of the following modes is generally adopted (1) roughening or chemical modification treatment is carried out on the surface of the copper foil, (2) a special adhesive with high polarity or high bonding force is adopted, and (3) the thickness of the adhesive layer is increased to improve the fault tolerance of an interface. However, the applicant found that the process is complicated and the stability is affected by batch when relying on surface roughening or chemical modification, the interface is easy to generate shear stress concentration under the repeated bending or thermal cycle conditions to cause delamination or peeling, and the interface stress state is difficult to be fundamentally improved simply by improving the adhesive force of the adhesive layer. Therefore, there is a need for a rubberized, rolled copper foil and a method of making the same that is capable of improving the interface stress pattern from the material internal structural level without relying on dedicated chemical coupling modifications to the copper surface, thereby improving the bonding stability between the bondline and the rolled copper foil. Disclosure of Invention The invention aims to provide a rubberized rolled copper foil and a manufacturing method thereof, wherein an elongated grain structure which is continuously fibrotically distributed along a rolling direction is built in a rolled copper foil base material, so that the interface stress state of the rolled copper foil after being compounded with a functional adhesive layer is improved, and the interface bonding stability between the functional adhesive layer and the rolled copper foil is improved. The method has the core technology that an elongated grain structure which is continuously fibrotically distributed along the rolling direction is constructed in the rolled copper foil base material through the cooperative control of differential rolling and segmented annealing for inhibiting complete recrystallization, and the structure is used in a composite system with a functional adhesive layer so as to improve the stress state of a composite interface and the interface bonding stability. 1. Mechanism for constructing continuous fibrosis elongated grain structure The invention does not adopt common symmetrical cold rolling and complete recrystallization annealing to prepare the rolled copper foil, but obtains the rolled copper foil base material through the following cooperative process paths: 1) Introducing differential rolling in the cold rolling process of high total reduction rate; 2) In the cold rolling process, a sectional annealing is performed when the cumulative rolling reduction reaches a certain interval to recover partial plasticity and suppress complete recrystallization. The obtained grain structure is different from the common rolled copper foil structure which mainly comprises equiaxed recrystallized grains or is only locally elongated in the prior art, and the difference can be comprehensively judged by combining indexes such as AR, ftex, rho, recrystallized volume fraction and the like carried by the specification. The key point of the invention is that under the action of repeated bending or thermal stress, the stress state of the composite interface can influence the interface reliability of the gluing rolled copper foil. The continuous fiberization elongation grain structure is beneficial to improving the load transmission mode of the rolled copper foil base material in the bending or thermal deformation process, thereby being beneficial to improving the interfa