Preparation method of rolled copper foil, rolled copper foil and application thereof

Abstract

This invention relates to the field of copper foil manufacturing technology, and particularly to a method for preparing rolled copper foil, rolled copper foil, and its applications. The preparation method includes a finishing rolling step: rolling a copper strip in N passes, with at least the Nth pass having a rolling speed of 750–800 m / min, to obtain rolled copper foil. Since a faster rolling speed results in more rolling oil being applied to the surface of the copper foil, the oil film strength is greater, thereby reducing deformation and damage to the copper foil during rolling, improving its flatness and surface finish, and reducing surface roughness. Therefore, this invention can produce rolled copper foil with low surface roughness. Furthermore, this invention has the advantages of simple process flow, convenient operation, high production efficiency, and low production cost, and has broad application prospects. In addition, the copper foil product of this invention has excellent performance and can meet the application requirements of high precision and high reliability.

Description

Technical Field

[0001] This invention relates to the field of copper foil production and manufacturing technology, and in particular to the preparation method of rolled copper foil, rolled copper foil and its applications. Background Technology

[0002] Copper foil, as a crucial raw material in the electronics industry, is widely used in circuit boards and printed circuit boards (PCBs). As a vital component of the conductive layer on PCB substrates, the surface roughness of copper foil significantly impacts signal transmission loss. In high-frequency signal transmission, the skin effect occurs, and higher surface roughness leads to greater signal loss. To reduce high-frequency signal transmission loss, low-profile or smooth-surface copper foil is required. To adapt to the rapid development of information network technology and the increasingly higher demands on the speed and efficiency of information processing in electronic products, low-profile copper foil is a key means to improve the signal transmission speed of PCBs and reduce signal loss and attenuation during high-speed signal transmission.

[0003] However, existing copper foil manufacturing processes often fall short of meeting the demands for high precision and high reliability in applications. In particular, the surface roughness of the copper foil directly affects its electrical and processing properties. Therefore, how to produce copper foil with low roughness is a pressing issue that needs to be addressed. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide a rolled copper foil and a method for preparing the same to overcome or at least partially solve the above problems, thereby solving the problem of high surface roughness of existing rolled copper foils.

[0005] On one hand, the present invention provides a method for preparing rolled copper foil, comprising:

[0006] Finishing rolling step: The copper strip is rolled in N passes, with the rolling speed of at least the Nth pass being 750-800 m / min, to obtain rolled copper foil; where N is an integer and N≥5.

[0007] Optionally, in the finishing rolling step, the rolling speed of the (N-1)th rolling pass is 750–800 m / min; and / or

[0008] In the finishing rolling step, the rolling speed of the N-2th rolling pass is 750-800 m / min.

[0009] Optionally, in the finishing rolling step, the rolling speed of the first rolling pass to the (N-3)th rolling pass is less than the rolling speed of the Nth rolling pass.

[0010] Optionally, the rolling speed gradually increases from the first rolling pass to the Nth rolling pass.

[0011] Optionally, in the finishing rolling step, the rolling oil includes an extreme pressure anti-wear agent, and the extreme pressure anti-wear agent accounts for 5-12% by mass in the rolling oil; and / or

[0012] In the finishing rolling step, the kinematic viscosity of the rolling oil is required to be 6.4–6.8 mm. 2 / s, the required Pb value for oil film strength is 52-55kg for four balls.

[0013] Optionally, in the finishing rolling step, the surface roughness Ra of the rolling work rolls is ≤0.03 μm; and / or

[0014] The thickness of the copper strip is 0.200 mm; and / or

[0015] The copper strip is TU00 oxygen-free copper; and / or

[0016] The thickness of the rolled copper foil obtained in the finishing rolling step is 0.018 mm; and / or

[0017] The rolling speed from the first rolling pass to the N-3 rolling pass is 400-600 m / min.

[0018] Optionally, the preparation method further includes:

[0019] Surface treatment step: The rolled copper foil is subjected to surface treatment, which includes at least a degreasing process, so that the Ra of the rolled copper foil is 0.03-0.05μm and the Rz is 0.2-0.4μm.

[0020] Optionally, in the finishing rolling step, the copper strip is rolled in seven passes sequentially, specifically including the following processes:

[0021] The first rolling process has a reduction rate of 36.0%, a total inlet tension of 3500N, a total outlet tension of 5500N, a rolling force of 450KN, and a rolling speed of 450~500m / min.

[0022] The second rolling process has a reduction rate of 29.6%, a total inlet tension of 3100N, a total outlet tension of 4100N, a rolling force of 450KN, and a rolling speed of 450~500m / min.

[0023] The third rolling process has a reduction rate of 28.8%, a total inlet tension of 2600N, a total outlet tension of 3200N, a rolling force of 450KN, and a rolling speed of 450~500m / min.

[0024] The fourth rolling process has a reduction rate of 26.5%, a total inlet tension of 1700N, a total outlet tension of 2100N, a rolling force of 450KN, and a rolling speed of 450-500m / min.

[0025] The fifth rolling pass has a reduction rate of 25.5%, a total inlet tension of 1300N, a total outlet tension of 1500N, a rolling force of 400KN, and a rolling speed of 750-800m / min.

[0026] The sixth rolling process has a reduction rate of 25.7%, a total inlet tension of 1000N, a total outlet tension of 1200N, a rolling force of 400KN, and a rolling speed of 750-800m / min.

[0027] The seventh rolling pass has a reduction rate of 30.7%, a total inlet tension of 800 N, a total outlet tension of 950 N, a rolling force of 400 KN, and a rolling speed of 750–800 m / min.

[0028] On the other hand, the present invention also provides a rolled copper foil prepared by any of the above-described preparation methods.

[0029] In another aspect, the present invention also provides an application of rolled copper foil prepared by any of the above-described methods in high-frequency circuits, 5G communications, or high-speed sensors.

[0030] In the method for preparing rolled copper foil, the rolled copper foil, and its application according to the present invention, during the finishing rolling process, at least in the last rolling pass, a speed-tension mode is used for thinning, increasing the rolling speed to 750-800 m / min. Since a faster rolling speed results in more rolling oil being carried onto the surface of the copper foil, the strength of the oil film is greater, thereby reducing deformation and damage to the copper foil during rolling, improving the flatness and surface finish of the copper foil, and helping to reduce the surface roughness of the copper foil. Therefore, the present invention can produce rolled copper foil with low surface roughness.

[0031] Furthermore, the rolled copper foil of the present invention can maintain good conductivity and physical properties.

[0032] Furthermore, the copper foil products obtained by this invention have excellent performance and can meet the application requirements of high precision and high reliability.

[0033] Furthermore, the preparation method of the present invention has the advantages of simple process flow, convenient operation, high production efficiency and low production cost, and has broad application prospects.

[0034] Therefore, those skilled in the art will more readily understand the above and other objects, advantages and features of the present invention from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0035] The following sections will describe some specific embodiments of the invention in a detailed manner, by way of example and not limitation, with reference to the accompanying drawings. In the drawings:

[0036] Figure 1 This is a schematic flowchart of a method for preparing rolled copper foil according to an embodiment of the present invention. Detailed Implementation

[0037] The following reference Figure 1 This invention describes the preparation method of rolled copper foil, the rolled copper foil, and its applications.

[0038] This invention provides a method for preparing rolled copper foil, which includes a finishing rolling step. The finishing rolling step involves rolling a copper strip in N passes, with at least the rolling speed of the Nth pass being 750–800 m / min, to obtain rolled copper foil; wherein N is an integer and N ≥ 5.

[0039] Specifically, copper strip is used as the base material. The rolling speed of the Nth rolling pass can be any one of 750 m / min, 760 m / min, 770 m / min, 780 m / min, 790 m / min, and 800 m / min. Preferably, the rolling speed of the Nth rolling pass is 800 m / min.

[0040] In this embodiment, during the finishing rolling process, a speed-tension mode is used for thinning at least in the last rolling pass, increasing the rolling speed to 750-800 m / min. The faster the rolling speed, the more rolling oil is carried onto the copper foil surface, resulting in a stronger oil film. This reduces deformation and damage to the copper foil during rolling, improves its flatness and surface finish, and yields rolled copper foil with low surface roughness. Furthermore, the copper foil obtained using this embodiment maintains good conductivity and physical properties. Even further, the copper foil product obtained through this embodiment exhibits excellent performance, meeting the requirements of high-precision and high-reliability applications. Moreover, the preparation method of this embodiment has the advantages of simple process flow, high production efficiency, convenient operation, and low production cost, and has broad application prospects.

[0041] In some optional embodiments of the present invention, N is 5 to 7. For example, N is 5, 6, or 7. The specific quantity of N can be selected according to the thickness of the copper strip base material and the required thickness of the rolled copper foil product.

[0042] In some optional embodiments of the present invention, in the finishing rolling step, the rolling speed of the (N-1)th rolling pass is 750–800 m / min. For example, the rolling speed of the (N-1)th rolling pass can be any one of 750 m / min, 760 m / min, 770 m / min, 780 m / min, 790 m / min, and 800 m / min. Preferably, the rolling speed of the (N-1)th rolling pass is 800 m / min. Using the method of this embodiment, deformation and damage to the copper foil during the rolling process can be further reduced, the flatness and surface finish of the copper foil can be improved, and the surface roughness of the copper foil can be further reduced, resulting in rolled copper foil with lower surface roughness.

[0043] In some optional embodiments of the present invention, in the finishing rolling step, the rolling speed of the (N-1)th rolling pass is 750–800 m / min; the rolling speed of the (N-2)th rolling pass is 750–800 m / min. Preferably, the rolling speed of the (N-1)th and (N-2)th rolling passes is 800 m / min. Using the method of this embodiment, deformation and damage to the copper foil during rolling can be further reduced, the flatness and surface finish of the copper foil can be improved, and the surface roughness of the copper foil can be further reduced, resulting in rolled copper foil with lower surface roughness.

[0044] In some optional embodiments of the present invention, in the finishing rolling step, the rolling speed of the first rolling pass to the (N-3)th rolling pass is lower than the rolling speed of the Nth rolling pass. In this embodiment, since the work hardening degree of the base material is high in the first few finishing rolling passes, a relatively low rolling speed is used in the first rolling pass to the (N-3)th rolling pass to reduce the thickness of the copper strip through the rolling force control mode, so as to avoid internal stress and cracks in the work rolls that would reduce the surface flatness of the copper foil, thereby enabling the copper foil to have better surface flatness.

[0045] Preferably, the rolling speed from the first rolling pass to the (N-3)th rolling pass is 400–600 m / min. For example, the rolling speed from the first rolling pass to the (N-3)th rolling pass can be any one of 400 m / min, 450 m / min, 500 m / min, 550 m / min, and 600 m / min.

[0046] More preferably, the rolling speed from the first rolling pass to the N-3 rolling pass is 450-500 m / min.

[0047] In some optional embodiments of the present invention, the rolling speed gradually increases from the first pass to the Nth pass in the finishing rolling step. Specifically, in the early stage of the rolling process, the thickness is reduced by the rolling force control mode. As the copper foil thickness decreases, when the copper foil thickness is less than 50 μm, the rolling force and roll gap control modes can no longer meet the requirements for copper foil thickness reduction. At this time, the speed tension control mode is needed to continue rolling thinning. Furthermore, in the rolling process, as the copper foil thickness decreases, increasing the rolling speed not only helps to improve production efficiency, but also increases the amount of rolling oil on the surface of the copper foil, thereby increasing the oil film strength, reducing deformation and damage of the copper foil during the rolling process, improving the flatness and surface smoothness of the copper foil, and further reducing the surface roughness of the copper foil to obtain rolled copper foil with lower surface roughness.

[0048] In some optional embodiments of the present invention, the copper strip is rolled in seven passes in sequence during the finishing rolling step, specifically including the following processes:

[0049] The first rolling process has a reduction rate of 36.0%, a total inlet tension of 3500N, a total outlet tension of 5500N, a rolling force of 450KN, and a rolling speed of 450~550m / min.

[0050] The second rolling process has a reduction rate of 29.6%, a total inlet tension of 3100N, a total outlet tension of 4100N, a rolling force of 450KN, and a rolling speed of 450~500m / min.

[0051] The third rolling process has a reduction rate of 28.8%, a total inlet tension of 2600N, a total outlet tension of 3200N, a rolling force of 450KN, and a rolling speed of 450~500m / min.

[0052] The fourth rolling process has a reduction rate of 26.5%, a total inlet tension of 1700N, a total outlet tension of 2100N, a rolling force of 450KN, and a rolling speed of 450-500m / min.

[0053] The fifth rolling pass has a reduction rate of 25.5%, a total inlet tension of 1300N, a total outlet tension of 1500N, a rolling force of 400KN, and a rolling speed of 750-800m / min.

[0054] The sixth rolling process has a reduction rate of 25.7%, a total inlet tension of 1000N, a total outlet tension of 1200N, a rolling force of 400KN, and a rolling speed of 750-800m / min.

[0055] The seventh rolling pass has a reduction rate of 30.7%, a total inlet tension of 800 N, a total outlet tension of 950 N, a rolling force of 400 KN, and a rolling speed of 750–800 m / min.

[0056] In some optional embodiments of the present invention, in the finishing rolling step, the rolling oil includes an extreme pressure anti-wear agent, and the extreme pressure anti-wear agent accounts for 5-12% (e.g., 5%, 8%, 10%, or 12%) of the mass percentage in the rolling oil. Specifically, the extreme pressure anti-wear agent is a phosphate ester. In this embodiment, due to the high content of extreme pressure anti-wear agent in the rolling oil, wear and scratches on the copper foil during the rolling process can be reduced, which is more conducive to improving the surface smoothness and surface finish of the copper foil, and more conducive to reducing the surface roughness of the copper foil.

[0057] In some optional embodiments of the present invention, the kinematic viscosity of the rolling oil in the finishing rolling step is required to be 6.4–6.8 mm. 2 / s (e.g., 6.4mm) 2 / s, 6.5mm 2 / s, 6.6mm 2 / s, 6.7mm 2 / s or 6.8mm 2 The oil film strength Pb value of the four balls is required to be 52-55 kg (e.g., 52 kg, 53 kg, 54 kg or 55 kg) to ensure effective lubrication and cooling during the rolling process.

[0058] In some optional embodiments of the present invention, the rolling oil used in the finishing rolling step comprises, by mass percentage, the following components: 80-92% base oil, 1-5% oiliness agent, 5-12% extreme pressure anti-wear agent, 1-2% antioxidant, and 1-5% surfactant.

[0059] In some optional embodiments of the present invention, in the finishing rolling step, the surface roughness Ra of the work rolls used for rolling is ≤0.03μm. Specifically, the work rolls are polished and made of high-hardness, high-wear-resistant 9Cr2Mo steel to ensure polishing effect and rigidity. Using work rolls with a surface roughness Ra ≤0.03μm is more conducive to improving the surface flatness and smoothness of the copper foil, and more conducive to reducing the surface roughness of the copper foil.

[0060] In some alternative embodiments of the present invention, the thickness of the copper strip is 0.200 mm.

[0061] In some alternative embodiments of the present invention, the copper strip is oxygen-free copper.

[0062] Preferably, the copper strip is TU00 oxygen-free copper, and the copper content in the copper strip is 99.99%. Specifically, the mass percentage of copper in the copper strip is 99.99%.

[0063] More preferably, the element content requirements in the copper strip are as follows: Cu+Ag≥99.99%, S≤0.0015%, Fe≤0.001%, Zn≤0.0001%, Sn≤0.002%, Bi≤0.0001%, Sb≤0.0004%, Ni≤0.001%, Pb≤0.0005%, O≤0.0005%. In this embodiment, the element content refers to the mass percentage of the element in the copper strip.

[0064] In this embodiment, oxygen-free copper strip is used as the base material, which can reduce the generation of peeling and pinholes during the rolling process, thereby facilitating the final obtaining of copper foil with low surface roughness.

[0065] In some optional embodiments of the present invention, the thickness of the rolled copper foil obtained by the finishing rolling step is 0.018 mm.

[0066] In some optional embodiments of the present invention, the method for preparing rolled copper foil further includes a surface treatment step.

[0067] Surface treatment steps: The rolled copper foil is surface treated so that the Ra of the surface-treated rolled copper foil is 0.03-0.05μm and the Rz is 0.2-0.4μm.

[0068] Specifically, Ra is an abbreviation for Roughness Average, which represents the average surface roughness. Rz is an abbreviation for Rauhigkeitaverage (Z), which is called the overall surface roughness.

[0069] In this embodiment, the Ra of the surface-treated rolled copper foil can be any one of 0.03μm, 0.035μm, 0.04μm, 0.045μm, and 0.05μm. Rz can be any one of 0.2μm, 0.25μm, 0.3μm, 0.35μm, and 0.4μm. Surface treatment of the rolled copper foil obtained in the finishing rolling step can further reduce the surface roughness of the rolled copper foil.

[0070] Furthermore, the surface cleaning process includes at least a degreasing step to improve the appearance quality of the copper foil and ultimately obtain copper foil with low surface roughness.

[0071] Furthermore, the degreasing solution includes an organic solvent, that is, an organic solvent is used to degrease the rolled copper foil; and after the degreasing process, the copper foil is dried.

[0072] Furthermore, the degreasing solution contains a passivating agent, which is added during the degreasing process to prevent oxidation on the surface of the rolled copper foil.

[0073] To further understand the present invention, the following detailed description of a method for preparing rolled copper foil provided by the present invention is provided in conjunction with embodiments.

[0074] Example 1

[0075] like Figure 1 As shown, a method for preparing rolled copper foil includes the following steps:

[0076] (1) Selection of base material: TU00 oxygen-free copper with a thickness of 0.200mm was used as the base material. The copper strip, calculated by mass percentage, includes the following components: Cu+Ag≥99.99%, S≤0.0015%, Fe≤0.001%, Zn≤0.0001%, Sn≤0.002%, Bi≤0.0001%, Sb≤0.0004%, Ni≤0.001%, Pb≤0.0005%, O≤0.0005%.

[0077] (2) Finishing rolling: The total rolling process is set to 7 rolling passes.

[0078] The first rolling pass has the following characteristics: the entry thickness is 0.200 mm, the exit thickness is 0.128 mm, the reduction rate is 36.0%, the total entry tension is 3500 N, the total exit tension is 5500 N, the rolling force is 450 KN, and the rolling speed is 450 m / min.

[0079] The second rolling process has the following parameters: the entry thickness is 0.128 mm, the exit thickness is 0.090 mm, the reduction rate is 29.6%, the total entry tension is 3100 N, the total exit tension is 4100 N, the rolling force is 450 KN, and the rolling speed is 450 m / min.

[0080] The third rolling process has the following parameters: the entry thickness is 0.090 mm, the exit thickness is 0.064 mm, the reduction rate is 28.8%, the total entry tension is 2600 N, the total exit tension is 3200 N, the rolling force is 450 KN, and the rolling speed is 500 m / min.

[0081] The fourth rolling process has the following characteristics: the entry thickness is 0.064 mm, the exit thickness is 0.047 mm, the reduction rate is 26.5%, the total entry tension is 1700 N, the total exit tension is 2100 N, the rolling force is 450 KN, and the rolling speed is 500 m / min.

[0082] The fifth rolling pass has the following characteristics: the entry thickness is 0.047 mm, the exit thickness is 0.035 mm, the reduction rate is 25.5%, the total entry tension is 1300 N, the total exit tension is 1500 N, the rolling force is 400 KN, and the rolling speed is 800 m / min.

[0083] The sixth rolling pass has the following characteristics: the entry thickness is 0.035 mm, the exit thickness is 0.026 mm, the reduction rate is 25.7%, the total entry tension is 1000 N, the total exit tension is 1200 N, the rolling force is 400 KN, and the rolling speed is 800 m / min.

[0084] The seventh rolling process has the following characteristics: the entry thickness is 0.026 mm, the exit thickness is 0.018 mm, the reduction rate is 30.7%, the total entry tension is 800 N, the total exit tension is 950 N, the rolling force is 400 KN, and the rolling speed is 800 m / min.

[0085] The final product is a rolled copper foil with a thickness of 0.018 mm.

[0086] The work rolls used in rolling are polished and made of high-hardness, high-wear-resistant materials, with a surface roughness Ra ≤ 0.03 μm. High-speed rotary calendering is used in passes 5 to 7. The rolling oil, by weight percentage, comprises the following components: 80–92% base oil, 1–5% oiliness agent, 5–12% extreme pressure anti-wear agent, 1–2% antioxidant, and 1–5% surfactant. The kinematic viscosity of the rolling oil is required to be 6.4–6.8 mm. 2 / s, the required Pb value for oil film strength is 52-55kg for four balls.

[0087] (3) The finished copper foil is subjected to subsequent processing, including degreasing and drying. Specifically, the finished rolled copper foil is first degreased with an organic solvent, and a passivating agent is added during the degreasing process to prevent oxidation of the surface of the rolled copper foil; then, it is dried.

[0088] (4) Cool the rolled copper foil to obtain the finished rolled copper foil with a surface roughness of Ra = 0.03~0.05μm and Rz = 0.2~0.4μm.

[0089] In this embodiment, firstly, using oxygen-free copper strip as the base material reduces peeling and pinholes during rolling. Secondly, using rolling oil with high anti-wear agents reduces wear and scratches on the copper foil during rolling. Thirdly, increasing the rolling speed of the copper foil shortens the rolling time and increases the amount of rolling oil on the copper foil surface, thereby increasing the oil film strength and reducing deformation and damage during rolling. Fourthly, using polished work rolls for precision rolling of the copper strip effectively reduces friction between the roll surface and the copper foil during rolling. Fifthly, degreasing and anti-oxidation treatment improve the surface quality of the copper foil, ultimately obtaining a copper foil with low surface roughness. The combined effect of these measures results in a copper foil with low roughness. Therefore, compared with the prior art, this embodiment effectively reduces the surface roughness of rolled copper foil while maintaining good conductivity and physical properties. In summary, this embodiment effectively reduces the surface roughness of copper foil by selecting high-purity oxygen-free copper, using polishing working rolls, selecting rolling oil with high anti-wear agent, and increasing the rolling speed in the rolling process. Finally, the copper foil is degreased and subjected to anti-oxidation treatment, thus maintaining the good appearance quality and physical properties of the copper foil.

[0090] Furthermore, the low-roughness copper foil products obtained through the above embodiments have excellent performance and can meet the application requirements of high precision and high reliability.

[0091] Furthermore, the preparation method of this embodiment has the advantages of simple process flow, convenient operation and low production cost, and has broad application prospects.

[0092] Comparative example:

[0093] A method for preparing rolled copper foil includes the following steps:

[0094] (1) Selection of base material: T2 oxygen-containing copper strip with a thickness of 0.200 mm was selected as the base material. The copper strip, calculated by mass percentage, includes the following components: Cu+Ag≥99.95%, P≤0.0015%, Fe≤0.003%, Zn≤0.005%, Sn≤0.002%, Bi≤0.001%, Sb≤0.002%, Ni≤0.002%, Pb≤0.003%, O≤0.02%.

[0095] (2) Finishing rolling: The total rolling process is set to 7 rolling passes.

[0096] The first rolling pass has the following characteristics: the entry thickness is 0.200 mm, the exit thickness is 0.128 mm, the reduction rate is 36.0%, the total entry tension is 3500 N, the total exit tension is 5500 N, the rolling force is 450 KN, and the rolling speed is 500 m / min.

[0097] The second rolling process has the following parameters: the entry thickness is 0.128 mm, the exit thickness is 0.090 mm, the reduction rate is 29.6%, the total entry tension is 3100 N, the total exit tension is 4100 N, the rolling force is 450 KN, and the rolling speed is 500 m / min.

[0098] The third rolling process has the following parameters: the entry thickness is 0.090 mm, the exit thickness is 0.064 mm, the reduction rate is 28.8%, the total entry tension is 2600 N, the total exit tension is 3200 N, the rolling force is 450 KN, and the rolling speed is 500 m / min.

[0099] The fourth rolling process has the following characteristics: the entry thickness is 0.064 mm, the exit thickness is 0.047 mm, the reduction rate is 26.5%, the total entry tension is 1700 N, the total exit tension is 2100 N, the rolling force is 450 KN, and the rolling speed is 500 m / min.

[0100] The fifth rolling pass has the following characteristics: the entry thickness is 0.047 mm, the exit thickness is 0.035 mm, the reduction rate is 25.5%, the total entry tension is 1300 N, the total exit tension is 1500 N, the rolling force is 450 KN, and the rolling speed is 650 m / min.

[0101] The sixth rolling process has the following characteristics: the entry thickness is 0.035 mm, the exit thickness is 0.026 mm, the reduction rate is 25.7%, the total entry tension is 1000 N, the total exit tension is 1200 N, the rolling force is 450 KN, and the rolling speed is 650 m / min.

[0102] The seventh rolling pass has the following characteristics: the entry thickness is 0.026 mm, the exit thickness is 0.018 mm, the reduction rate is 30.7%, the total entry tension is 800 N, the total exit tension is 950 N, the rolling force is 450 KN, and the rolling speed is 650 m / min.

[0103] The final product is a rolled copper foil with a thickness of 0.018 mm.

[0104] The working rolls used for rolling were not polished, and their surface roughness was Ra = 0.06 μm.

[0105] (3) The copper foil after precision rolling is subjected to subsequent processing, including degreasing and drying.

[0106] (4) Cool the rolled copper foil to obtain the finished rolled copper foil with a surface roughness of Ra = 0.06~0.10μm and Rz = 0.5~0.8μm.

[0107] Compared with Comparative Example 1, the surface roughness of the rolled copper foil product obtained in Example 1 was significantly reduced.

[0108] In addition, this embodiment of the invention also provides a rolled copper foil, which is prepared by the preparation method described in any of the above embodiments.

[0109] Furthermore, this invention also provides an application of the rolled copper foil prepared by the preparation method described in any of the above embodiments in the fields of high-frequency circuits, 5G communication, or high-speed sensors.

[0110] While this invention provides several exemplary embodiments, many other variations or modifications consistent with the principles of this invention can be directly determined or derived from the disclosure of this invention without departing from its spirit and scope. Therefore, the scope of this invention should be understood and recognized as covering all such other variations or modifications.

Claims

1. A method for preparing rolled copper foil, characterized in that, include: Finishing rolling step: Rolling a copper strip with a thickness of 0.200mm in N passes to obtain rolled copper foil with a thickness of 0.018mm; Wherein, N is an integer and N≥5; the copper strip is TU00 oxygen-free copper; The rolling speed from the first rolling pass to the N-3 rolling pass is 400-600 m / min; the rolling speed for the N-2 rolling pass, the N-1 rolling pass, and the Nth rolling pass is 800 m / min. The rolling oil used, by weight percentage, comprises the following components: 80-92% base oil, 1-5% oiliness agent, 5-12% extreme pressure anti-wear agent, 1-2% antioxidant, and 1-5% surfactant; the extreme pressure anti-wear agent is a phosphate ester; the kinematic viscosity of the rolling oil is required to be 6.4-6.8 mm. 2 / s, the required Pb value for oil film strength in four-ball bearings is 52-55kg; The surface roughness Ra of the rolling mill rolls is ≤0.03μm; the material of the rolling mill rolls is 9Cr2Mo steel; Surface treatment step: The rolled copper foil is subjected to surface treatment, which includes at least a degreasing process, so that the Ra of the rolled copper foil is 0.03-0.05μm and the Rz is 0.2-0.4μm.

2. The preparation method according to claim 1, characterized in that, In the finishing rolling step, the copper strip is rolled in seven passes, specifically including the following processes: The first rolling process has a reduction rate of 36.0%, a total inlet tension of 3500N, a total outlet tension of 5500N, a rolling force of 450KN, and a rolling speed of 450~500m / min. The second rolling process has a reduction rate of 29.6%, a total inlet tension of 3100N, a total outlet tension of 4100N, a rolling force of 450KN, and a rolling speed of 450~500m / min. The third rolling process has a reduction rate of 28.8%, a total inlet tension of 2600N, a total outlet tension of 3200N, a rolling force of 450KN, and a rolling speed of 450~500m / min. The fourth rolling process has a reduction rate of 26.5%, a total inlet tension of 1700N, a total outlet tension of 2100N, a rolling force of 450KN, and a rolling speed of 450-500m / min. The fifth rolling pass has a reduction rate of 25.5%, a total inlet tension of 1300N, a total outlet tension of 1500N, a rolling force of 400KN, and a rolling speed of 800m / min. The sixth rolling pass has a reduction rate of 25.7%, a total inlet tension of 1000N, a total outlet tension of 1200N, a rolling force of 400KN, and a rolling speed of 800m / min. The seventh rolling pass has a reduction rate of 30.7%, a total inlet tension of 800 N, a total outlet tension of 950 N, a rolling force of 400 KN, and a rolling speed of 800 m / min.

3. A rolled copper foil prepared by any one of claims 1-2.

4. An application of a rolled copper foil prepared by any one of claims 1-2 in high-frequency circuits, 5G communication, or high-speed sensors.

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