Copper foil for printed circuit board and method for producing the same

Abstract

To provide a copper foil for a printed circuit board and a method for producing the same.SOLUTION: A production method comprising performing a multi-stage electroplating process to sequentially form a metal release layer, a copper pyrophosphate layer, and a copper sulfate layer. The multi-stage electroplating process comprises a metal release electroplating step, a copper pyrophosphate electroplating step, and a copper sulfate electroplating step.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a copper foil and a method for manufacturing the same, and more particularly to a copper foil for printed circuit boards and a method for manufacturing the same. [Background technology]

[0002] Ultra-thin copper foils are widely used in electronic and electrical engineering printed circuit boards (PCBs). For ultra-thin copper foil products for PCB fine lines, if pinholes exist in the ultra-thin copper foil, they may cover the PCB lines and cause line defects. Therefore, it is essential that the ultra-thin copper foil is pinhole-free. In the prior art, the electroplating section of ultra-thin copper foil is usually one-step electroplating, or at most two-step electroplating. The electroplating conditions for one-step electroplating are uniform and unchangeable, which makes it difficult to form a dense and uniform plating layer, leading to the formation of pinholes in the plating layer.

[0003] Based on the above, it is an urgent goal for those skilled in the art to develop a manufacturing process for pinhole-free ultra-thin copper foil, thereby realizing pinhole-free ultra-thin copper foil. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention provides a copper foil for printed circuit boards and a manufacturing method thereof, which can produce an ultra-thin copper foil for printed circuit boards without pinholes, thereby avoiding the problem of line defects caused by pinholes. [Means for solving the problem]

[0005] The method for producing a copper foil for printed circuit boards of the present invention comprises sequentially forming a metal release layer, a copper pyrophosphate layer, and a copper sulfate layer by carrying out a multi-step electroplating process, the multi-step electroplating process comprising a metal release electroplating process, a copper pyrophosphate electroplating process, and a copper sulfate electroplating process.

[0006] In one embodiment of the present invention, the components of the metallic release layer include Ni, W, Zn, Mo, Co, or combinations thereof.

[0007] In one embodiment of the present invention, the electroplating conditions of 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, and the electroplating temperature is 25°C to 60°C.

[0008] In one embodiment of the present invention, the thickness of the metal release layer is 10 nm to 300 nm.

[0009] In one embodiment of the present invention, the copper pyrophosphate layer has a thickness of 10 nm to 300 nm.

[0010] In one embodiment of the present invention, the composition of the copper pyrophosphate layer is 5g / L to 25g / L of copper pyrophosphate ions, 100g / L to 300g / L of potassium pyrophosphate, and the pH value is adjusted to 9 to 10 with NH3OH.

[0011] In one embodiment of the present invention, the electroplating conditions of the copper pyrophosphate electroplating process are 2ASD to 20ASD, the time is 2 seconds to 20 seconds, the copper pyrophosphate electroplating process is a 2-step to 6-step electroplating process, and the electroplating temperature is 25°C to 60°C.

[0012] In one embodiment of the present invention, the composition of the copper sulfate layer is 70 g / L to 90 g / L of copper ions and 60 g / L to 150 g / L of sulfuric acid.

[0013] In one embodiment of the present invention, the electroplating conditions of the copper sulfate electroplating process are 5ASD to 30ASD, the time is 2 seconds to 20 seconds, and the copper sulfate electroplating process is 4-stage to 8-stage electroplating.

[0014] In one embodiment of the present invention, the copper sulfate layer has a thickness of 1.5 μm to 3 μm.

[0015] The copper foil for printed circuit boards of the present invention is produced by the above-mentioned method for producing copper foil for printed circuit boards. [Effects of the Invention]

[0016] Based on the above, the present invention provides a copper foil for printed circuit boards and a manufacturing method thereof, which uses a multi-step electroplating process, including a metal release electroplating process, a copper pyrophosphate electroplating process, and a copper sulfate electroplating process, thereby making the electroplating layer dense and uniform, thereby preventing pinholes from forming between the plating layers. DETAILED DESCRIPTION OF THE INVENTION

[0017] Embodiments of the present invention are described in detail below, but these embodiments are illustrative and the disclosure of the present invention is not limited thereto.

[0018] In the present invention, a range expressed as "one value to another value" is a summary expression that avoids listing all values ​​within the range in the specification. Thus, the description of a particular numerical range covers any numerical value within that numerical range and any smaller range defined by that numerical value, as if such numerical value and smaller range were set forth in the specification.

[0019] The present invention provides a method for producing a copper foil for printed circuit boards, which includes a multi-step electroplating process to sequentially form a metal release layer, a copper pyrophosphate layer, and a copper sulfate layer. The multi-step electroplating process includes a metal release electroplating process, a copper pyrophosphate electroplating process, and a copper sulfate electroplating process.

[0020] In this embodiment, the components of the metal release layer may include Ni, W, Zn, Mo, Co, or a combination thereof. The electroplating conditions for the metal release electroplating step are, for example, 2ASD to 20ASD, the time is, for example, 2 seconds to 20 seconds, the metal release electroplating step is, for example, two-stage to six-stage electroplating, and the electroplating temperature is, for example, 25°C to 60°C. The composition of the copper pyrophosphate layer is, for example, 5 g / L to 25 g / L of copper pyrophosphate ions and 100 g / L to 300 g / L of potassium pyrophosphate, and the pH value is adjusted to, for example, 9 to 10 using NH3OH. The electroplating conditions for the copper pyrophosphate electroplating step are, for example, 2ASD to 20ASD, the time is, for example, 2 seconds to 20 seconds, the copper pyrophosphate electroplating step is, for example, two-stage to six-stage electroplating, and the electroplating temperature is, for example, 25°C to 60°C. The composition of the copper sulfate layer is, for example, 70g / L to 90g / L of copper ions and 60g / L to 150g / L of sulfuric acid. The electroplating conditions for the copper sulfate electroplating process are, for example, 5ASD to 30ASD, and the time is, for example, 2 seconds to 20 seconds, and the copper sulfate electroplating process is, for example, 4-stage to 8-stage electroplating. The thickness of the metal release layer is, for example, 10nm to 300nm, and the thickness of the copper sulfate layer is, for example, 1.5μm to 3μm.

[0021] In this embodiment, a pickling and chromic acid treatment sequence may be performed in sequence before the multi-stage electroplating process, and a surface roughening treatment, chromic acid treatment, and silane treatment may be performed in sequence after the multi-stage electroplating process. The pickling and chromic acid treatment sequence, and the surface roughening treatment, chromic acid treatment, and silane treatment process conditions are all well-known conditions and can be adjusted by those skilled in the art according to the actual operating conditions, so a detailed description is omitted here. More specifically, the pickling conditions are, for example, 90 to 110 g / L of sulfuric acid. The chromic acid conditions are, for example, 3 g / L to 6 g / L of chromium, 10 seconds. The surface roughening conditions are, for example, Cu. +2 8g / L~20g / L, 60ASD~80ASD, 2 seconds~3 seconds, Cu +2 The concentration is 40g / L to 60g / L, 10ASD to 30ASD, and 15 seconds to 30 seconds. The heat-resistant metal layer contains Ni, W, Zn, Mo, and Co, and has a thickness of, for example, 1nm to 5nm. For silane treatment, an appropriate prepreg is selected and mixed with silane.

[0022] The present invention also provides a copper foil for printed circuit boards produced by the above-mentioned method for producing a copper foil for printed circuit boards, wherein the copper foil for printed circuit boards comprises a metal release layer, a copper pyrophosphate layer, and a copper sulfate layer in this order.

[0023] The copper foil for printed circuit boards and the manufacturing method thereof presented in the above-mentioned embodiments will be described in detail below by way of experimental examples, but the following experimental examples are not intended to limit the present invention.

[0024] From Table 1 below, it can be seen that Examples 1 to 4 employ the method for producing copper foil for printed circuit boards of the present invention, and use a multi-step electroplating process to form a plating layer comprising a metal release layer, a copper pyrophosphate layer, and a copper sulfate layer, thereby making the electroplated layer dense and uniform and preventing pinholes from forming between the plating layers, thereby producing ultra-thin copper foil for pinhole-free printed circuit boards, thereby avoiding the problem of line defects due to pinholes. In contrast, Comparative Examples 1 and 2 do not employ the method for producing copper foil for printed circuit boards of the present invention, and therefore the peel force is not uniform, resulting in the formation of holes, which may cause pinholes and lead to the problem of line defects due to pinholes.

[0025] [Table 1]

[0026] In summary, the present invention provides a copper foil for printed circuit boards and a method for manufacturing the same, which uses a multi-step electroplating process. The multi-step electroplating process includes a metal release electroplating process, a copper pyrophosphate electroplating process, and a copper sulfate electroplating process, thereby forming an electroplated layer comprising a metal release layer, a copper pyrophosphate layer, and a copper sulfate layer. In this way, the electroplated layer is dense and uniform, thereby preventing pinholes from forming between the plating layers, and producing an ultra-thin copper foil for printed circuit boards that is free of pinholes, thereby avoiding the problem of line defects caused by pinholes. [Industrial Applicability]

[0027] The copper foil for printed circuit boards and the method for producing the same of the present invention can be applied to the electronics and electrical engineering materials industry.

Claims

1. performing a multi-step electroplating process to sequentially form a metal release layer, a copper pyrophosphate layer, and a copper sulfate layer; The multi-step electroplating process includes a metal release electroplating process, a copper pyrophosphate electroplating process, and a copper sulfate electroplating process. A method for manufacturing copper foil for printed circuit boards.

2. The components of the metal release layer include Ni, W, Zn, Mo, Co, or a combination thereof; The method for producing the copper foil for printed circuit boards according to claim 1.

3. The electroplating conditions of the metal release electroplating process are 2 ASD to 20 ASD, the time is 2 seconds to 20 seconds, the metal release electroplating process is a 2-step to 6-step electroplating, and the electroplating temperature is 25°C to 60°C. The method for producing the copper foil for printed circuit boards according to claim 1.

4. The thickness of the metal release layer is 10 nm to 300 nm. The method for producing the copper foil for printed circuit boards according to claim 1.

5. The composition of the copper pyrophosphate layer is 5 g / L to 25 g / L of copper pyrophosphate ions, 100 g / L to 300 g / L of potassium pyrophosphate, and NH ３ The pH value is adjusted to 9-10 by OH. The method for producing the copper foil for printed circuit boards according to claim 1.

6. The thickness of the copper pyrophosphate layer is 10 nm to 300 nm; The method for producing the copper foil for printed circuit boards according to claim 1.

7. The electroplating conditions of the copper pyrophosphate electroplating process are 2ASD to 20ASD, the time is 2 seconds to 20 seconds, the copper pyrophosphate electroplating process is a 2-step to 6-step electroplating process, and the electroplating temperature is 25°C to 60°C. The method for producing the copper foil for printed circuit boards according to claim 1.

8. The composition of the copper sulfate layer is 70 g / L to 90 g / L of copper ions and 60 g / L to 150 g / L of sulfuric acid. The method for producing the copper foil for printed circuit boards according to claim 1.

9. The electroplating conditions of the copper sulfate electroplating process are 5 ASD to 30 ASD, and the time is 2 seconds to 20 seconds, and the copper sulfate electroplating process is a 4-step to 8-step electroplating process. The method for producing the copper foil for printed circuit boards according to claim 1.

10. The thickness of the copper sulfate layer is 1.5 μm to 3 μm. The method for producing the copper foil for printed circuit boards according to claim 1.

11. Produced by the method for producing a copper foil for printed circuit boards according to any one of claims 1 to 10, Copper foil for printed circuit boards.

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