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CN-121988611-A - Manufacturing method of rolled copper foil for high-speed cable shielding and rolled copper foil

CN121988611ACN 121988611 ACN121988611 ACN 121988611ACN-121988611-A

Abstract

The invention relates to the technical field of high-speed cable shielding materials, and discloses a manufacturing method of a rolled copper foil for high-speed cable shielding. The method comprises the steps of preparing a copper plate, carrying out multiple cold rolling on the copper plate to form an elongated grain structure oriented along a rolling direction, carrying out controlled annealing on the cold-rolled copper foil to recover plasticity and inhibit complete recrystallization, carrying out finish rolling to obtain a target thickness, carrying out finishing rolling on at least one surface of the copper foil by adopting a mirror work roll to reduce surface roughness, and carrying out surface smoothing or passivation treatment to inhibit oxidation and performance degradation. The rolled copper foil thus obtained has good ductility, structural stability and high frequency properties.

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 (16)

  1. 1. A method of manufacturing a rolled copper foil for high speed cable shielding, comprising: a) Providing copper or copper alloy raw materials; b) Carrying out multi-pass cold rolling on the raw materials to ensure that the total reduction rate is more than or equal to 95%; c) Annealing the cold rolled strip to a non-fully recrystallized state and retaining a rolling direction oriented elongated grain structure, wherein the non-fully recrystallized state satisfies an EBSD statistical recrystallization grain area fraction <50%; d) Finish rolling the annealed strip to obtain a rolled copper foil with a thickness of 5-12 μm and a thickness uniformity of not more than + -5%; e) Adopting a mirror face working roller to carry out finishing rolling, wherein the finishing rolling reduction is 0.5-2.0%, and the roller surface roughness Ra of the mirror face working roller is less than or equal to 0.02 mu m; f) Carrying out surface smoothing or passivation treatment on the polished copper foil to form a continuous surface layer with the thickness less than or equal to 50 nm; wherein, after the steps e) and f), the surface roughness Ra of at least one surface of the copper foil is less than or equal to 0.25 mu m.
  2. 2. The method for producing a rolled copper foil for high-speed cable shielding according to claim 1, wherein the total reduction is 98% or more, preferably 99% or more.
  3. 3. The method for producing a rolled copper foil for high-speed cable shielding according to claim 1 or 2, wherein the annealing temperature is 350 to 420 ℃.
  4. 4. The method for producing a rolled copper foil for high speed cable shielding according to claim 1, wherein the incompletely recrystallized state satisfies the EBSD statistics of a recrystallized grain area fraction <50%, preferably <30%.
  5. 5. The method of producing a rolled copper foil for high speed cable shielding according to claim 1, wherein the aspect ratio of the crystal grains after step c) is not less than 3:1, preferably not less than 5:1.
  6. 6. The method for producing a rolled copper foil for high speed cable shielding according to claim 1, wherein said thickness uniformity is not more than.+ -. 4%.
  7. 7. The method for producing a rolled copper foil for high speed cable shielding according to claim 1, wherein the surface roughness Ra of said copper foil after steps e) and f) is 0.15 μm or less.
  8. 8. The method for producing a rolled copper foil for high speed cable shielding according to claim 7, wherein the surface roughness Ra is 0.10 μm or less.
  9. 9. The method for producing a rolled copper foil for high-speed cable shielding according to claim 1, wherein the coverage of the continuous surface layer is not less than 90%, preferably not less than 95%.
  10. 10. A rolled copper foil for high speed cable shielding, characterized in that: a) The thickness is 5-12 mu m; b) The internal crystal grains are distributed in an oriented elongated form along the rolling direction, and the aspect ratio of the crystal grains is more than or equal to 3:1; c) The surface roughness Ra of at least one surface of the copper foil is less than or equal to 0.25 mu m; d) The surface of the copper foil is provided with a continuous surface layer with coverage rate not lower than 90%, and the thickness of the continuous surface layer is less than or equal to 50 nm; e) The copper foil internal structure satisfies the EBSD statistics of a recrystallized grain area fraction <50% and maintains an oriented elongated morphology along the rolling direction.
  11. 11. The rolled copper foil for high speed cable shielding of claim 10 wherein the aspect ratio of the grains is 5:1 or more.
  12. 12. The rolled copper foil for high speed cable shielding according to claim 10, wherein the surface roughness Ra is 0.15 μm or less.
  13. 13. The rolled copper foil for high speed cable shielding according to claim 12, wherein the surface roughness Ra is 0.10 μm or less.
  14. 14. The rolled copper foil for high-speed cable shielding according to claim 10, wherein the coverage of the continuous surface layer is not less than 90%, preferably not less than 95%.
  15. 15. The rolled copper foil for high speed cable shielding according to claim 10, wherein the thickness of the continuous surface layer is 30 nm or less.
  16. 16. The calendered copper foil for high speed cable shielding of claim 10, wherein the incompletely recrystallized state satisfies the EBSD statistics by a recrystallized grain area fraction of <50%, preferably <30%.

Description

Manufacturing method of rolled copper foil for high-speed cable shielding and rolled copper foil Technical Field The invention relates to a Polytetrafluoroethylene (PTFE) composite rolled copper foil which is formed by continuously distributing a fiber elongated grain structure along a rolling direction in a rolled copper foil through high total reduction rate cold rolling, rear section continuous differential rolling and sectional annealing cooperative control for inhibiting complete recrystallization and is formed by compositing the rolled copper foil with PTFE on the basis, and a manufacturing method thereof, which can inhibit crack initiation of the metal foil in a folded edge and a lap joint area in a high-speed coating process on the premise of not reducing the coating line speed and not increasing the thickness of the metal foil, and is mainly used for manufacturing the rolled copper foil for 224G and 448G high-speed cables, and belongs to the technical field of high-speed data transmission composite metal foil materials. Background With the development of high-speed data transmission systems, when a high-speed cable works in a higher frequency band, higher requirements are put on the surface state, the tissue stability and the bending reliability of a shielding layer material. The surface roughness, grain morphology and surface layer stability of the rolled copper foil as a cable shielding layer material can influence the signal integrity and long-term use reliability under the high-frequency transmission condition. At present, the applicant finds that when the conventional rolled copper foil is used for a high-speed communication cable shielding layer in the manufacture of a high-speed cable composite copper foil, the problems of poor deformation degree or improper tissue control, unfavorable balance between flexibility and structural stability due to limited grain orientation and elongation degree, unfavorable stability of transmission performance under a high-frequency condition when the surface roughness is higher, and easy influence on the consistency of the surface state of the copper foil and long-term use reliability when the surface layer is insufficiently controlled still exist. Disclosure of Invention The invention aims to provide a manufacturing method of a rolled copper foil for high-speed cable shielding and the rolled copper foil, which are used for obtaining the rolled copper foil with an oriented elongated grain structure, lower surface roughness and stable surface layer on the premise of being capable of being industrially implemented by reasonably combining cold rolling, annealing, finish rolling, mirror finishing and surface smoothing or passivation treatment processes. To achieve the above design objective. The invention relates to a method for manufacturing a semiconductor device, which comprises the following steps of: casting, multi-pass cold rolling, annealing, finish rolling, mirror finish rolling, and surface smoothing or passivation treatment. The above processes can be implemented on existing copper foil continuous production lines, and only the key process window needs to be controlled. The industrial implementation mode of the steps is as follows: And a step a) of casting, namely providing copper raw materials and performing casting to form a copper plate. In industrial practice, the copper feedstock has a purity of not less than 99.99 wt% and an oxygen content of not more than 10: 10 ppm is controlled by smelting and refining to reduce the adverse effects of impurities on subsequent extensibility and surface quality. And b) carrying out multi-pass cold rolling on the copper plate to form a rolled copper foil blank with a grain structure elongated along the rolling direction. In industrial production, the total reduction rate of multiple cold rolling is not lower than 95%, and a typical rolled structure is formed in a pass-by-pass thinning mode, so that a foundation is provided for subsequent high ductility and surface leveling. And c) annealing treatment, namely annealing the rolled copper foil blank to recover plasticity and improve ductility. The annealing temperature is controlled in the range of 350-420 ℃ and is performed in an inert atmosphere or a reducing atmosphere to inhibit oxidation and stabilize the grain structure. After annealing, the material is preferably left in a non-fully recrystallized state and retains an elongated grain structure oriented in the rolling direction. And d) finish rolling, namely, finish rolling the annealed rolled copper foil to reach the target thickness. In industrial practice, the thickness of the rolled copper foil after finish rolling is controlled to be 5-12 μm, and the thickness uniformity is not more than + -5%. And e) mirror surface finishing rolling, namely adopting a mirror surface working roller to finish and roll at least one surface of the rolled copper foil so as to reduce the surface roughness. The roller surface ro