Copper foil for printed wiring board and method for producing same
By using a multi-stage electroplating process to form a metal release layer, a pyrometallurgical layer, and a copper sulfate layer, the problem of pinholes in the electroplating process of ultra-thin copper foil is solved, enabling the manufacturing of pinhole-free printed circuit board copper foil and ensuring the reliability of the circuit.
Patent Information
- Application Number
- CN202410787399.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-05-23
- Filing Date
- 2024-06-18
- Publication Date
- 2025-11-25
AI Technical Summary
Existing ultrathin copper foil is prone to pinholes during electroplating, leading to circuit failure on printed circuit boards. Current technologies struggle to form dense and uniform plating layers.
A multi-stage electroplating process is adopted, including metal release plating, copper pyrophosphate plating, and copper sulfate plating, to form a metal release layer, a pyrophosphate layer, and a copper sulfate layer. The electroplating conditions and temperature are controlled to ensure that the plating layer is dense and uniform.
It enables the manufacture of ultra-thin copper foil without pinholes, avoiding circuit failure problems and ensuring the density and uniformity of the electroplated layer.
Smart Images
Figure BDA0004898978980000041
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to a copper foil and a manufacturing method thereof, and relates to a copper foil for printed circuit board and a manufacturing method thereof. BACKGROUND
[0002] Ultra-thin copper foils are widely used in printed circuit boards (PCBs) for electronic and electrical materials. For ultra-thin copper foils for fine lines of PCBs, when pinholes exist in the ultra-thin copper foils, the pinholes may cover the lines of the PCBs, thereby causing line failure. Therefore, the ultra-thin copper foils must be pinhole-free. In the prior art, the electroplating section of the ultra-thin copper foils is usually one-stage electroplating or at most two-stage electroplating. The electroplating conditions of one-stage electroplating are single and cannot be changed, and the plating layer is prone to not being able to form a dense and uniform layer, and thus pinholes in the plating layer are easily formed.
[0003] Based on the above, a pinhole-free process for ultra-thin copper foils is developed to achieve pinhole-free ultra-thin copper foils, which is a goal desired to be developed by those skilled in the art. SUMMARY
[0004] The present application provides a copper foil for printed circuit board and a manufacturing method thereof, which can manufacture an ultra-thin copper foil for pinhole-free printed circuit board to avoid line failure problems caused by pinholes.
[0005] The manufacturing method of the copper foil for printed circuit board of the present application includes a multi-stage electroplating process to sequentially form a metal stripping layer, a cupric pyrophosphate layer, and a copper sulfate layer. The multi-stage electroplating process includes a metal stripping electroplating process, a cupric pyrophosphate electroplating process, and a copper sulfate electroplating process.
[0006] In an embodiment of the present application, the composition of the metal stripping layer includes Ni, W, Zn, Mo, Co, or a combination thereof.
[0007] In an embodiment of the present application, the electroplating conditions of the metal stripping electroplating process are 2 ASD to 20 ASD, the time is 2 seconds to 20 seconds, the metal stripping electroplating process is 2-stage to 6-stage electroplating, and the electroplating temperature is 25°C to 60°C.
[0008] In an embodiment of the present application, the thickness of the metal stripping layer is 10 nm to 300 nm.
[0009] In an embodiment of the present application, the thickness of the cupric pyrophosphate layer is 10 nm to 300 nm.
[0010] In an embodiment of the present application, the formula of the cupric pyrophosphate layer is cupric pyrophosphate ions 5 g / L to 25 g / L, potassium pyrophosphate 100 g / L to 300 g / L, and NH3OH to control the pH to 9 to 10.
[0011] In an embodiment of the present application, the plating conditions of the copper pyrophosphate plating process are 2 ASD to 20 ASD, the time is 2 seconds to 20 seconds, and the copper pyrophosphate plating process is a 2-stage to 6-stage plating, and the plating temperature is 25°C to 60°C.
[0012] In an embodiment of the present application, the formula of the copper sulfate layer is copper ions 70 g / L to 90 g / L and sulfuric acid 60 g / L to 150 g / L.
[0013] In an embodiment of the present application, the plating conditions of the copper sulfate plating process are 5 ASD to 30 ASD, the time is 2 seconds to 20 seconds, and the copper sulfate plating process is a 4-stage to 8-stage plating.
[0014] In an embodiment of the present application, the thickness of the copper sulfate layer is 1.5 μm to 3 μm.
[0015] The copper foil for printed circuit board of the present application is made by the manufacturing method of the copper foil for printed circuit board.
[0016] Based on the above, the present application provides a copper foil for printed circuit board and a manufacturing method thereof, the manufacturing method utilizes a multi-stage plating process, the multi-stage plating process includes a metal ion type plating process, a copper pyrophosphate plating process, and a copper sulfate plating process, so that the plating layer is dense and uniform, and no pinholes are generated between the plating layers. BRIEF DESCRIPTION OF DRAWINGS
[0017] None DETAILED DESCRIPTION
[0018] Hereinafter, embodiments of the present application will be described in detail. However, these embodiments are exemplary, and the present application is not limited thereto.
[0019] In this context, a range expressed by "a numerical value to another numerical value" is a summary representation for avoiding listing all numerical values in the range one by one in the specification. Therefore, the description of a certain numerical value range encompasses any numerical value in the numerical value range and a smaller numerical value range defined by any numerical value in the numerical value range, as if the any numerical value and the smaller numerical value range are described in the specification.
[0020] The present application provides a manufacturing method of a copper foil for printed circuit board. The method includes performing a multi-stage plating process to sequentially form a metal ion type layer, a copper pyrophosphate layer, and a copper sulfate layer, and the multi-stage plating process includes a metal ion type plating process, a copper pyrophosphate plating process, and a copper sulfate plating process.
[0021] In this embodiment, the metal release layer may be composed of multiple components, including Ni, W, Zn, Mo, Co, or combinations thereof. The electroplating conditions for the metal release electroplating process are, for example, 2 ASD to 20 ASD, with a time of, for example, 2 to 20 seconds, and the process may be a 2- to 6-stage electroplating, with an electroplating temperature of, for example, 25°C to 60°C. The formulation of the pyrophosphate copper layer is, for example, 5 g / L to 25 g / L of copper pyrophosphate ions, 100 g / L to 300 g / L of potassium pyrophosphate, and pH adjusted to, for example, 9 to 10 with NH3OH. The electroplating conditions for the copper pyrophosphate copper plating process are, for example, 2 ASD to 20 ASD, with a time of, for example, 2 to 20 seconds, and the process may be a 2- to 6-stage electroplating, with an electroplating temperature of, for example, 25°C to 60°C. The formulation of the copper sulfate layer is, for example, 70 g / L to 90 g / L of copper ions and 60 g / L to 150 g / L of sulfuric acid. The electroplating conditions for the copper sulfate electroplating process are, for example, 5 ASD to 30 ASD, and the time is, for example, 2 seconds to 20 seconds. The copper sulfate electroplating process is, for example, a 4-stage to 8-stage electroplating process. The thickness of the metal release layer is, for example, 10 nm to 300 nm, and the thickness of the copper sulfate layer is, for example, 1.5 μm to 3 μm.
[0022] In this embodiment, before the multi-stage electroplating process, pickling and chromic acid processes can be performed sequentially. After the multi-stage electroplating process, roughening, chromic acid, and silane treatments can be performed sequentially. The pickling and chromic acid processes, as well as the process conditions for roughening, chromic acid, and silane treatments, are all known conditions and can be adjusted by those skilled in the art according to actual operating conditions. Therefore, they will not be described in detail here. More specifically, the pickling conditions are, for example, sulfuric acid 90-110 g / L 10 s; the chromic acid conditions are, for example, chromium 3-6 g / L 10 s; and the roughening conditions are, for example, Cu+2 8-20 g / L 60 ASD-80 ASD 2-3 s, or Cu+2 40-60 g / L 10 ASD-30 ASD 15-30 s. The heat-resistant metal layer contains Ni, W, Zn, Mo, and Co, and its thickness is, for example, 1 nm to 5 nm. As for the silane treatment, a suitable prepreg is selected to complement it.
[0023] The present invention also provides a copper foil for printed circuit boards, which is manufactured by the above-described method for manufacturing copper foil for printed circuit boards, wherein the copper foil for printed circuit boards sequentially comprises a metal release layer, a pyrometallurgical layer and a copper sulfate layer.
[0024] The copper foil for printed circuit boards and its manufacturing method described in the above embodiments will be explained in detail below through experimental examples. However, the following experimental examples are not intended to limit the present invention.
[0025] As shown in Table 1 below, Examples 1 to 4 employ the manufacturing method of copper foil for printed circuit boards according to the present invention. A multi-stage electroplating process is used to form an electroplated layer having a metal release layer, a pyrometallurgical layer, and a copper sulfate layer. This results in a dense and uniform electroplated layer, eliminating pinholes between plating layers and producing pinhole-free ultra-thin copper foil for printed circuit boards, thereby avoiding circuit failures caused by pinholes. In contrast, Comparative Examples 1 and 2 do not use the manufacturing method of copper foil for printed circuit boards according to the present invention. Therefore, uneven tearing force forms holes, resulting in pinholes, which may lead to circuit failures.
[0026] Table 1
[0027]
[0028] In summary, the present invention provides a copper foil for printed circuit boards and a method for manufacturing the same. The manufacturing method utilizes a multi-stage electroplating process, which includes a metal release electroplating process, a copper pyrophosphate electroplating process, and a copper sulfate electroplating process to form an electroplated layer having a metal release layer, a copper pyrophosphate layer, and a copper sulfate layer. In this way, the electroplated layer can be made dense and uniform, so as to achieve no pinholes between the plating layers, and to manufacture an ultra-thin copper foil for printed circuit boards without pinholes, thereby avoiding the circuit failure problem caused by pinholes.
Claims
1. A method for manufacturing copper foil for printed circuit boards, characterized in that, include: A multi-stage electroplating process is performed to sequentially form a metal release layer, a copper plating layer, and a copper sulfate layer. The multi-stage electroplating process includes a metal release electroplating process, a copper pyrophosphate electroplating process, and a copper sulfate electroplating process.
2. The method for manufacturing copper foil for printed circuit boards according to claim 1, characterized in that, The composition of the metal release layer includes Ni, W, Zn, Mo, Co, or combinations thereof.
3. The method for manufacturing copper foil for printed circuit boards according to claim 1, characterized in that, The electroplating conditions for the metal release electroplating process are 2ASD to 20ASD, the time is 2 seconds to 20 seconds, the metal release electroplating process is a 2-stage to 6-stage electroplating process, and the electroplating temperature is 25 to 60°C.
4. The method for manufacturing copper foil for printed circuit boards according to claim 1, characterized in that, The thickness of the metal release layer is 10 nm to 300 nm.
5. The method for manufacturing copper foil for printed circuit boards according to claim 1, characterized in that, The formulation of the copper pyrophosphate layer is 5 g / L to 25 g / L copper pyrophosphate ions, 100 g / L to 300 g / L potassium pyrophosphate, and NH3OH to adjust the pH to 9 to 10.
6. The method for manufacturing copper foil for printed circuit boards according to claim 1, characterized in that, The thickness of the copper plating layer is 10 nm to 300 nm.
7. The method for manufacturing copper foil for printed circuit boards according to claim 1, characterized in that, The electroplating conditions for the copper pyrophosphate electroplating process are 2 ASD to 20 ASD, the time is 2 seconds to 20 seconds, the copper pyrophosphate electroplating process is a 2-stage to 6-stage electroplating process, and the electroplating temperature is 25 to 60°C.
8. The method for manufacturing copper foil for printed circuit boards according to claim 1, characterized in that, The copper sulfate layer is formulated with 70 g / L to 90 g / L copper ions and 60 g / L to 150 g / L sulfuric acid.
9. The method for manufacturing copper foil for printed circuit boards according to claim 1, characterized in that, The electroplating conditions for the copper sulfate electroplating process are 5 ASD to 30 ASD, and the time is 2 seconds to 20 seconds. The copper sulfate electroplating process is a 4-stage to 8-stage electroplating process.
10. The method for manufacturing copper foil for printed circuit boards according to claim 1, characterized in that, The thickness of the copper sulfate layer is 1.5 μm to 3 μm.
11. A copper foil for printed circuit boards, manufactured by the method of manufacturing copper foil for printed circuit boards according to any one of claims 1 to 10.