Method for producing roughened copper foil
Through the improvement of the electrolyte formulation and electrolytic process, combined with the silanization treatment process, the challenge of manufacturing a roughened layer with low roughness and high adhesion on the copper foil is solved, and the excellent adhesion and low roughness between the copper foil and the insulating resin are achieved.
Patent Information
- Application Number
- CN202311363565.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-09-19
- Filing Date
- 2023-10-20
- Publication Date
- 2025-03-21
AI Technical Summary
In the context of the development of fine circuits of printed circuit boards (PCB), how to make a roughened layer with low roughness and high adhesion on copper foil, which not only meets the refinement needs of the copper foil surface, but also maintains high adhesion.
By improving the electrolyte formulation, including copper ions between 0.1 g/L to 20 g/L, sulfate ions between 30 g/L to 120 g/L, and malformants between 0.1 g/L to 10 g/L, the electrolytic process is performed to form a roughened treatment layer, and optionally a silanization treatment process is performed to enhance adhesion.
A roughening treatment layer with low roughness (surface roughness less than 1 micron) and high adhesion is achieved on the copper foil, ensuring that the peel strength between the copper foil and the insulating resin is at least greater than 4 lb/in.
Abstract
Description
Technical Field
[0001] The invention relates to a method for manufacturing a roughened copper foil. Background Art
[0002] With the development of fine lines on printed circuit boards (PCBs), the roughening layer on the surface of the copper foil needs to become finer, but at the same time, the high adhesion between the copper foil and the insulating resin must be maintained. Therefore, how to produce a roughening layer with low roughness and high adhesion on the copper foil is a challenge. Summary of the invention
[0003] The invention provides a method for manufacturing a roughened copper foil, which can manufacture a roughened treatment layer with low roughness and high adhesion on the copper foil.
[0004] The method for manufacturing a roughened copper foil of the present invention comprises the following steps: providing a copper foil; performing an electrolytic process to form a roughening treatment layer on the copper foil; the electrolyte in the electrolytic process comprises copper ions between 0.1 g / L and 20 g / L, sulfate ions between 30 g / L and 120 g / L, and complexes between 0.1 g / L and 10 g / L.
[0005] In one embodiment of the present invention, the complex comprises benzotriazole compounds, propane sulfonic acid compounds, ethylenediaminetetraacetic acid or a combination thereof.
[0006] In one embodiment of the present invention, no other metal ions are further added to the above-mentioned electrolyte.
[0007] In one embodiment of the present invention, the electrolysis process includes a first electrolysis process and a second electrolysis process, and the first copper ion concentration used in the first electrolysis process is less than the second copper ion concentration used in the second electrolysis process.
[0008] In one embodiment of the present invention, the first copper ion concentration is between 0.1 g / L and 10 g / L, and the second copper ion concentration is between 1 g / L and 20 g / L.
[0009] In one embodiment of the present invention, performing the electrolysis process further includes performing a silanization process.
[0010] In one embodiment of the present invention, the electrolysis process uses direct current.
[0011] In one embodiment of the present invention, the temperature of the electrolysis process is between 25° C. and 60° C.
[0012] In one embodiment of the present invention, the current density of the electrolysis process is between 1A / dm 2 Up to 120A / dm 2 between.
[0013] In one embodiment of the present invention, the duration of the electrolysis process is between 1 second and 45 seconds.
[0014] Based on the above, the present invention improves the electrolyte used to form the roughening treatment layer, so that it includes copper ions between 0.1g / L and 20g / L, sulfate ions between 30g / L and 120g / L, and complexes between 0.1g / L and 10g / L. In this way, the copper nodules constituting the roughening treatment layer can be generated with an excellent nucleation and growth mechanism, so that a roughening treatment layer with low roughness and high adhesion can be manufactured on the copper foil. DETAILED DESCRIPTION
[0015] In the following detailed description, for the purpose of illustration and not limitation, exemplary embodiments that disclose specific details are described to provide a thorough understanding of the various principles of the present invention. However, it will be apparent to one of ordinary skill in the art that, with the benefit of this disclosure, the present invention may be practiced in other embodiments that depart from the specific details disclosed herein. In addition, descriptions of well-known devices, methods, materials, and other specific details may be omitted to avoid obscuring the description of the various principles of the present invention.
[0016] In this article, the range expressed by "a value to another value" is a summary expression method to avoid listing all the values in the range one by one in the specification. Therefore, the description of a specific numerical range covers any value in the numerical range and a smaller numerical range defined by any value in the numerical range, just as the arbitrary value and the smaller numerical range are written in the description text of the specification.
[0017] Unless otherwise specified, the term "between" used in this specification to define a numerical range is intended to cover a range equal to the endpoint value and between the endpoint values. For example, a size range is between a first value and a second value, which means that the size range can cover the first value, the second value and any value between the first value and the second value.
[0018] In this document, non-limiting terms (such as may, could, for example, or other similar terms) mean optional or optional implementation, inclusion, addition, or presence.
[0019] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood or generally understood in the technical field to which the present invention belongs. It will also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the relevant technical context and should not be interpreted in an idealized or overly formal sense unless explicitly defined as such herein.
[0020] In this embodiment, the roughened copper foil is manufactured by, for example, the following steps. First, a copper foil is provided, and then an electrolytic process is performed to form a roughening treatment layer on the copper foil, wherein the present invention improves the electrolyte used to form the roughening treatment layer to include copper ions between 0.1 g / L and 20 g / L (for example, 0.1 g / L, 1 g / L, 10 g / L, 20 g / L, or any value between 0.1 g / L and 20 g / L), copper ions between 30 g / L and 120 g / L (for example, 30 g / L, 50 g / L, 70 g / L, 90 g / L, 120 g / L, or any value between 30 g / L and 120 g / L), and copper ions between 10 g / L and 20 g / L (for example, 20 g / L, 30 g / L, 50 g / L, 70 g / L, 90 g / L, 120 g / L, or any value between 30 g / L and 120 g / L). The invention relates to a method for preparing a roughening layer of copper foil. The method comprises the steps of: preparing a roughening layer of copper foil with a sulfate ion (SO42-) of at least 0.1 g / L and a complex of at least 0.1 g / L and 10 g / L (e.g., 0.1 g / L, 1 g / L, 3 g / L, 5 g / L, 7 g / L, 10 g / L or any value between 0.1 g / L and 10 g / L). In this way, the copper nodules constituting the roughening layer can be generated with an excellent nucleation and growth mechanism, such as a fast nucleation rate, so that a roughening layer with low roughness and high adhesion (high surface area and high peel strength) can be produced on the copper foil. Here, the surface roughness (e.g., ten-point average roughness, Rz) of the roughening layer formed by the above method is, for example, at least less than 1 micrometer, and the peel strength between the copper foil on which the roughening layer is formed and the insulating resin (Preppreg) is, for example, at least greater than 4 lb / in.
[0021] Furthermore, the electrolyte of the present invention introduces a complex compound, so compared with the electrolytic copper foil currently using only copper sulfate electrolyte, the complex compound reacts with copper to make the divalent copper ions (Cu 2+ ) can form copper ions of other valences (such as monovalent copper ions (Cu +)) to achieve excellent nucleation and growth mechanisms and optimize the generation ability of copper nodules in three-dimensional directions. For example, the complex of the present invention includes benzotriazole (BTA) compounds (ionic liquids), propane sulfonic acid compounds, ethylenediaminetetraacetic acid (EDTA) or a combination thereof, wherein the benzotriazole compound is selected from carboxybenzotriazole (CBTA), 1,2,3-benzotriazole, 1-chloro-1,2,3-benzotriazole, bis(N-2-ethylhexyl)aminomethylene-1,2,3-benzotriazole, bis(N-2-ethylhexyl)aminomethylene-1,2,3-toluenetriazole, bis(N-2-hydroxyethyl)aminomethylene-1,2,3-benzotriazole, and the propane sulfonic acid compound is selected from bis-(3-sulfopropyl)-disulfide disodium salt. salt, SPS), 3-mercapto-1-propanesulfonic acid (3-mercapto-1-propanesulfonic acid, MPS), but the present invention is not limited thereto.
[0022] In some embodiments, the method for manufacturing the roughened copper foil of the present invention may be applied to a circuit board, but the present invention is not limited thereto.
[0023] In some embodiments, no other metal ions are further added to the electrolyte. For example, the electrolyte of the present invention does not include metal ions such as iron (Fe) and cobalt (Co), that is, the electrolyte only includes a single metal ion (copper ion), but the present invention is not limited to this.
[0024] In some embodiments, the electrolysis process can be performed in multiple stages to more effectively obtain the desired copper nodules. For example, the electrolysis process includes a first electrolysis process and a second electrolysis process, and the first copper ion concentration used in the first electrolysis process is less than the second copper ion concentration used in the second electrolysis process. In this way, the copper nodules can be grown to a desired degree (such as dendritic growth) in the vertical direction by the first electrolysis process, and then the base portion of the copper nodules (the portion close to the copper foil) can be thickened by the second electrolysis process to enhance the adhesion between the copper nodules and the copper foil and prevent them from peeling off easily. The first copper ion concentration is between 0.1 / L and 10 g / L, and the second copper ion concentration is between 1 g / L and 20 g / L, but the present invention is not limited thereto.
[0025] Here, the size and shape of the copper nodule can be determined according to actual design requirements, and the present invention is not limited thereto. As long as the surface roughness (Rz) of the roughening layer can be at least less than 1 micron, and the peel strength between the copper foil on which the roughening layer is formed and the insulating resin (Preppreg) can be at least greater than 4 lb / in, it falls within the protection scope of the present invention.
[0026] In some embodiments, the thickness of the copper foil is between 1.5 micrometers and 70 micrometers, but the invention is not limited thereto.
[0027] In some embodiments, the electrolysis process is followed by a silanization process to form an additional silane coupling layer on the surface of the roughening layer relative to the copper foil, thereby further enhancing the bonding strength between the roughening layer and other film layers. The silanization process can be performed using a silane coupling agent such as acryloxypropyltrimethoxysilane or the like, but the present invention is not limited thereto.
[0028] In some embodiments, the electrolysis process is operated under direct current, and the temperature of the electrolysis process is between 25°C and 60°C (for example, 25°C, 35°C, 45°C, 55°C, 60°C, or any value between 25°C and 60°C), and the current density of the electrolysis process is between 1A / dm 2 (ASD) to 120A / dm 2 Between (for example, 1A / dm 2 、10A / dm 2 、30A / dm 2 、50A / dm 2 、80A / dm 2 、120A / dm 2 or above between 1A / dm 2 Up to 120A / dm 2 ), the time of the electrolysis process is between 1 second and 45 seconds (for example, 1 second, 10 seconds, 20 seconds, 30 seconds, 45 seconds or any value between 1 second and 45 seconds), but the present invention is not limited thereto.
[0029] In some embodiments, when the copper trough body of the present invention does not add benzotriazole but adds a benzotriazole compound, its surface roughness (Rz) is between 1 micron and 1.5 microns, and the peeling force is >4lb / in. In comparison, when the copper trough body does not add benzotriazole or a benzotriazole compound, its surface roughness is between 1 micron and 1.5 microns, and the peeling force is <3lb / in, but the present invention is not limited to this.
[0030] The following examples and comparative examples are listed to illustrate the effects of the present invention, but the scope of the present invention is not limited to the scope of the examples.
[0031] The roughened copper foil prepared by the electrolyte formulations of the embodiments and comparative examples in Table 1 was used to prepare a copper foil substrate of model NPG170D, and was evaluated according to the following method.
[0032] Surface roughness (Rz): Tested using laser or white light.
[0033] Peel strength: According to the IPC-TM-650-2.4.8 test method, the peel strength of the metal substrate is tested.
[0034] The relevant properties of the copper foil substrate were tested, and the results are shown in Table 1. By comparing the results of the embodiment and the comparative example in Table 1, the following conclusion can be drawn: adding the benzotriazole complex can improve the peeling force.
[0035] Table 1
[0036] Comparative Example 1 Example 1 Copper ion concentration g / L 8 8 Sulfate ion concentration g / L 90 90 Complex concentration g / L 0 1.0 Temperature ℃ Room temperature (25℃) Room temperature (25℃) Current density ASD 65 65 Time 2 2 Surface roughness (Rz)um 1.2 1.2 Peel strength lb / in 2.5 4.2
[0037] In summary, the present invention improves the electrolyte used to form the roughening treatment layer, so that it includes copper ions between 0.1g / L and 20g / L, sulfate ions between 30g / L and 120g / L, and complexes between 0.1g / L and 10g / L. In this way, the copper nodules constituting the roughening treatment layer can be generated with an excellent nucleation and growth mechanism, so that a roughening treatment layer with low roughness and high adhesion can be manufactured on the copper foil.
[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for producing a roughened copper foil, characterized in that: include: Provide copper foil; as well as An electrolytic process is performed to form a roughening treatment layer on the copper foil, wherein the electrolyte in the electrolytic process includes copper ions between 0.1 g / L and 20 g / L, sulfate ions between 30 g / L and 120 g / L, and complexes between 0.1 g / L and 10 g / L.
2. The method for producing a roughened copper foil according to claim 1, wherein: The complex comprises benzotriazole compounds, propane sulfonic acid compounds, ethylenediaminetetraacetic acid or a combination thereof.
3. The method for producing a roughened copper foil according to claim 1, wherein: No other metal ions are further added to the electrolyte.
4. The method for producing a roughened copper foil according to claim 1, wherein: The electrolysis process includes a first electrolysis process and a second electrolysis process, and a first copper ion concentration used in the first electrolysis process is less than a second copper ion concentration used in the second electrolysis process.
5. The method for producing a roughened copper foil according to claim 4, wherein: The first copper ion concentration is between 0.1 g / L and 10 g / L, and the second copper ion concentration is between 1 g / L and 20 g / L.
6. The method for producing a roughened copper foil according to claim 1, wherein: The method further includes performing a silanization process after performing the electrolysis process.
7. The method for producing a roughened copper foil according to claim 1, wherein: The electrolysis process uses direct current.
8. The method for producing a roughened copper foil according to claim 1, wherein: The temperature of the electrolysis process is between 25°C and 60°C.
9. The method for producing a roughened copper foil according to claim 1, wherein: The current density of the electrolysis process is between 1A / dm 2 Up to 120A / dm 2 between.
10. The method for producing a roughened copper foil according to claim 1, wherein: The duration of the electrolysis process is between 1 second and 45 seconds.