Method for producing aluminum-based copper foil
By controlling the temperature of the coating drum and depositing nickel-chromium as the underlayer during the preparation of aluminum-based copper foil, combined with the electroplating process, the problem of wrinkles on the aluminum foil film surface was solved, improving production yield and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUBEI ZHUOCHENG NEW MATERIALS TECHNOLOGY CO LTD
- Filing Date
- 2026-03-05
- Publication Date
- 2026-05-29
AI Technical Summary
In existing aluminum-based copper foil manufacturing processes, wrinkles easily appear on the aluminum foil film surface during the magnetron sputtering stage, resulting in low production yield and high cost.
The coating drum temperature is controlled at 32-35℃. A nickel-chromium underlayer is deposited on the aluminum foil substrate and magnetron sputtering is performed. Then, electroplating is carried out at a speed of 1-3m/min to form a copper foil layer, and an anti-oxidation layer is covered on the copper foil layer.
It effectively avoids wrinkles on the aluminum foil film surface, improves the production yield of aluminum-based copper foil, and reduces costs.
Smart Images
Figure CN122105402A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of aluminum-based copper foil technology, and specifically relates to a method for preparing aluminum-based copper foil. Background Technology
[0002] With the rapid development of the electronic information industry, electromagnetic shielding materials play a crucial role in ensuring the reliable operation of electronic equipment, preventing information leakage, and reducing electromagnetic radiation pollution. Among them, metal composite materials, especially aluminum-based copper foil with a lightweight aluminum matrix and a highly conductive copper layer, have become an ideal choice for flexible circuits, high-end shielding pads, and special cables due to their good conductivity, excellent electromagnetic shielding performance, and advantages in weight and cost.
[0003] Currently, the main manufacturing process for aluminum-based copper foil utilizes magnetron sputtering followed by electroplating. Magnetron sputtering deposits a thin copper layer onto the aluminum foil, which is then thickened using electroplating. However, in this existing process, wrinkles easily form on the aluminum foil surface during the magnetron sputtering stage, resulting in low yield and high cost for aluminum-based copper foil production. Summary of the Invention
[0004] In view of this, the present invention provides a method for preparing aluminum-based copper foil, which avoids the problem that wrinkles are very easy to occur on the aluminum foil film surface during the magnetron sputtering stage, improves the production yield of aluminum-based copper foil, and reduces costs.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a method for preparing aluminum-based copper foil, comprising the following steps: S1. Obtain aluminum foil substrate; S2. Sputter coating is performed using a coating drum, wherein the temperature of the coating drum is set to 32-35℃; S3. After magnetron sputtering is completed, the aluminum foil substrate after magnetron sputtering is electroplated with a coating at a speed of 1-2 m / min to obtain aluminum-based copper foil.
[0006] Preferably, in step S1, after obtaining the aluminum foil substrate, it is first vacuum-cooled to the required temperature, and then plasma-cleaned; and / or, In step S1, the thickness of the aluminum foil substrate is 9-200 μm.
[0007] Preferably, after step S1 and before sputtering the aluminum foil substrate, an underlayer is first deposited. The material of the underlayer includes nickel-chromium or nickel. It should be noted that the purpose of depositing the underlayer is to enhance the adhesion between the copper layer and the aluminum foil substrate.
[0008] Preferably, the thickness of the underlayer is 10-50 nm; and / or, The underlayer is deposited using argon as the sputtering gas.
[0009] Preferably, in step S2, the coating speed is 1-3 m / min, the sputtering power is 20-24 kW, the nickel-chromium target power is 1-2 kW, the argon flow rate of the ion source is 55 sccm, and the argon flow rate of the cathode is 50-80 sccm. In step S2, the thickness of the seed copper layer deposited by magnetron sputtering is 20-200 nm.
[0010] Preferably, in step S3, the electroplating coating uses an electroplating solution comprising 110 g / L anhydrous copper sulfate, 125 g / L sulfuric acid, 50 ppm chloride ions, 2 ml / L wetting agent, 0.2 ml / L brightener, and 2 ml / L leveling agent.
[0011] Preferably, in step S3, the electroplating current is 3043-7985A, and the maximum voltage of a single rectifier is ≤4V.
[0012] Preferably, in step S3, the electroplating film forms a copper foil layer with a thickness of 1-35 μm.
[0013] Preferably, the aluminum-based copper foil further includes an antioxidant layer covering the copper foil layer. The antioxidant layer is formed by reducing chromate with an organic reducing agent, preventing oxidation of the copper foil layer.
[0014] Preferably, the thickness of the antioxidant layer is 5-10 nm; The materials used to prepare the antioxidant layer include chromium anhydride and glucose.
[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention improves the production yield of aluminum-based copper foil and reduces costs by changing the preparation method of aluminum-based copper foil, thus avoiding the problem of wrinkles easily appearing on the aluminum foil film surface during the magnetron sputtering stage. Attached Figure Description
[0016] Figure 1 This is a flow chart of the magnetron sputtering + electroplating process provided by the present invention; Figure 2 These are structural diagrams of aluminum-based copper foil provided in Embodiments 1-4 and Comparative Examples 1-6 of the present invention.
[0017] Figure reference numerals: Aluminum foil substrate 100, underlayer 200, seed copper layer 300, copper foil layer 400, anti-oxidation layer 500. Detailed Implementation
[0018] The present invention will now be described in further detail with reference to specific embodiments, so that those skilled in the art can more clearly understand the present invention.
[0019] With the rapid development of the electronic information industry, electromagnetic shielding materials play a crucial role in ensuring the reliable operation of electronic equipment, preventing information leakage, and reducing electromagnetic radiation pollution. Among them, metal composite materials, especially aluminum-based copper foil with a lightweight aluminum matrix and a highly conductive copper layer, have become an ideal choice for flexible circuits, high-end shielding pads, and special cables due to their good conductivity, excellent electromagnetic shielding performance, and advantages in weight and cost.
[0020] Currently, the main manufacturing process for aluminum-based copper foil utilizes magnetron sputtering followed by electroplating. Magnetron sputtering deposits a thin copper layer onto the aluminum foil, which is then thickened using electroplating. However, in this existing process, wrinkles easily form on the aluminum foil surface during the magnetron sputtering stage, resulting in low yield and high cost for aluminum-based copper foil production.
[0021] To solve the above-mentioned technical problems, the present invention provides a method for preparing aluminum-based copper foil, comprising the following steps: S1. Obtain aluminum foil substrate 100; S2. Sputter coating is performed using a coating drum, wherein the temperature of the coating drum is set to 32-35℃; S3. After magnetron sputtering is completed, the magnetron sputtered aluminum foil substrate 100 is electroplated with a coating at a speed of 1-2 m / min to obtain aluminum-based copper foil.
[0022] Further, in step S1, after obtaining the aluminum foil substrate 100, it is first vacuum-cooled to the required temperature, and then plasma-cleaned; and / or, In step S1, the thickness of the aluminum foil substrate 100 is 9-200 μm.
[0023] Furthermore, after step S1 and before sputtering the aluminum foil substrate 100, an underlayer 200 is first deposited. The material of the underlayer 200 includes nickel-chromium or nickel. It should be noted that the purpose of depositing the underlayer 200 is to enhance the adhesion between the copper layer and the aluminum foil substrate 100.
[0024] Furthermore, the thickness of the underlying layer after applying 200 nm is 10-50 nm; and / or, The underlayer 200 is deposited using argon as the sputtering gas.
[0025] Further, in step S2, the coating speed is 1-3 m / min, the sputtering power is 20-24 kW, the nickel-chromium target power is 1-2 kW, the argon flow rate of the ion source is 55 sccm, and the argon flow rate of the cathode is 50-80 sccm. In step S2, the thickness of the seed copper layer 300 deposited by magnetron sputtering is 20-200 nm.
[0026] Furthermore, in step S3, the electroplating coating will use an electroplating solution, which includes 110 g / L anhydrous copper sulfate, 125 g / L sulfuric acid, 50 ppm chloride ions, 2 ml / L wetting agent, 0.2 ml / L brightener, and 2 ml / L leveling agent.
[0027] Furthermore, in step S3, the electroplating current is 3043-7985A, and the maximum voltage of a single rectifier is ≤4V.
[0028] Further, in step S3, an electroplating film is formed to form a copper foil layer 400 with a thickness of 1-35 μm.
[0029] Furthermore, the aluminum-based copper foil also includes an antioxidant layer 500 covering the copper foil layer 400. The antioxidant layer 500 is formed by reducing chromate with an organic reducing agent to prevent oxidation of the copper foil layer 400.
[0030] Furthermore, the thickness of the antioxidant layer 500 is 5-10 nm; The materials used to prepare the antioxidant layer 500 include chromium anhydride and glucose.
[0031] It should be noted that in some embodiments, magnetron sputtering is performed using a drum-type magnetron sputtering coating equipment. During the magnetron sputtering process, a general cooling system can be used to cool the coating drum at different temperatures. The principle is that the heat generated during the coating process is transferred to the evaporator of the cooling unit through a single water circulation. The cooling unit then discharges the heat into the atmosphere through the circulation system and continuously provides low-temperature cold water to the coating drum, thereby achieving coating at different temperatures.
[0032] The process flow for aluminum-based copper foil is as follows: Figure 1As shown, after the chamber vacuum is evacuated during the magnetron sputtering stage, if the coating drum requires cooling during the coating process, the cooling temperature is set and cooling is performed. After reaching the cooling temperature, the aluminum foil substrate 100 is plasma cleaned to remove the oxide layer on its surface. First, the front side of the aluminum foil substrate 100 is cleaned, and after copper plating on the front side, the reverse side is cleaned and copper plating is performed. The ion source voltage is 1-2.2KV, the current is 0.3-1A, and the argon flow rate is 50-80sccm. Then, sputtering coating is started using a multi-target method. Double-sided magnetron sputtering was used, with argon (5N) as the sputtering gas. First, a base layer 200 was deposited to enhance the bonding force between the copper layer and the aluminum foil substrate 100. Then, a seed copper layer 300 was deposited. The cathode argon flow rate was 80-120 sccm. After the seed copper layer 300 was deposited, the vacuum was broken by reheating. Samples from the next roll were taken for testing. After all physical properties met the standards, the seed copper layer 300 was electroplated to thicken it. Finally, an anti-oxidation layer 500 was deposited on the surface of the thickened copper layer to further prevent oxidation of the copper foil layer 400.
[0033] Example 1 This invention provides a method for preparing a seed copper layer 300 deposited on one side of an aluminum-based material, comprising the following steps: A 30μm thick 3003-H18 aluminum foil was selected as the substrate. Magnetron sputtering was performed using a drum-type magnetron sputtering equipment. After setting the drum temperature to 35℃, one side of the aluminum foil substrate 100 was plasma-cleaned to remove the oxide layer. The ion source voltage was 2.2KV, the current was 1A, and the argon flow rate was 80sccm. After cleaning, magnetron sputtering was performed on the cleaned side. The deposition speed was 3m / min, the total target sputtering power was 24kW, the nickel-chromium target power was 1kW, the ion source argon flow rate was 55sccm, and the cathode argon flow rate was 80sccm. Before deposition, argon (5N) was used as the sputtering gas to deposit a 200 layer with a thickness of 20nm. Then, a seed copper layer 300 with a thickness of 64nm was obtained.
[0034] Example 2 This invention provides a method for preparing a seed copper layer 300 deposited on one side of an aluminum-based material. The preparation method is the same as in Example 1, except that the coating drum temperature is 32°C, and magnetron sputtering is performed to obtain the seed copper layer 300. The thickness of the seed copper layer 300 is 60 nm.
[0035] Comparative Example 1 This invention provides a method for preparing a seed copper layer 300 deposited on one side of an aluminum-based material. The preparation method is the same as in Example 1, except that magnetron sputtering is performed at a deposition speed of 3 m / min, a total target sputtering power of 20 kW, a nickel-chromium target power of 1 kW, an argon flow rate of 55 sccm for the ion source, an argon flow rate of 80 sccm for the cathode, and a deposition drum temperature of -30°C to obtain the seed copper layer 300. The thickness of the seed copper layer 300 is 59 nm.
[0036] Comparative Example 2 This invention provides a method for preparing a seed copper layer 300 deposited on one side of an aluminum-based material. The preparation method is the same as in Example 1, except that magnetron sputtering is performed at a deposition speed of 1 m / min, a total target sputtering power of 7 kW, a nickel-chromium target power of 1 kW, an argon flow rate of 55 sccm for the ion source, an argon flow rate of 80 sccm for the cathode, and a deposition drum temperature of -25°C to obtain the seed copper layer 300. The thickness of the seed copper layer 300 is 62 nm.
[0037] Comparative Example 3 This invention provides a method for preparing a seed copper layer 300 deposited on one side of an aluminum-based material. The preparation method is the same as in Example 1, except that magnetron sputtering is performed at a deposition speed of 3 m / min, a total target sputtering power of 24 kW, a nickel-chromium target power of 1 kW, an argon flow rate of 55 sccm for the ion source, an argon flow rate of 80 sccm for the cathode, and a deposition drum temperature of -5°C to obtain the seed copper layer 300. The thickness of the seed copper layer 300 is 65 nm.
[0038] Comparative Example 4 This invention provides a method for preparing a seed copper layer 300 deposited on one side of an aluminum-based material. The preparation method is the same as in Example 1, except that magnetron sputtering is performed at a deposition speed of 3 m / min, a total target sputtering power of 24 kW, a nickel-chromium target power of 1 kW, an argon flow rate of 55 sccm for the ion source, an argon flow rate of 80 sccm for the cathode, and a deposition drum temperature of 0°C to obtain the seed copper layer 300. The thickness of the seed copper layer 300 is 59 nm.
[0039] Comparative Example 5 This invention provides a method for preparing a seed copper layer 300 deposited on one side of an aluminum-based material. The preparation method is the same as in Example 1, except that magnetron sputtering is performed at a deposition speed of 3 m / min, a total target sputtering power of 20 kW, a nickel-chromium target power of 1 kW, an argon flow rate of 55 sccm for the ion source, an argon flow rate of 80 sccm for the cathode, and a deposition drum temperature of 25°C to obtain the seed copper layer 300. The thickness of the seed copper layer 300 is 58 nm.
[0040] Example 3 This invention provides a method for preparing aluminum-based copper foil, comprising the following steps: A 30μm thick 3003-H18 aluminum foil was selected as the substrate. Magnetron sputtering was performed using a drum-type magnetron sputtering equipment. After setting the drum temperature to 35℃, one side of the aluminum foil substrate 100 was plasma-cleaned to remove the oxide layer. The ion source voltage was 2.2KV, the current was 1A, and the argon flow rate was 80sccm. After cleaning, magnetron sputtering was performed on the cleaned side. The deposition speed was 3m / min, the total target sputtering power was 24kW, the nickel-chromium target power was 1kW, the ion source argon flow rate was 55sccm, and the cathode argon flow rate was 80sccm. Before deposition, argon (5N) was used as the sputtering gas to deposit a 200 layer with a thickness of 20nm. Then, a seed copper layer 300 with a thickness of 64nm was obtained by depositing at a deposition speed of 3m / min. After depositing the seed copper layer 300, the temperature was returned to room temperature and the vacuum was broken. Samples from the next roll were taken for testing. Once all physical properties met the standards, the seed copper layer 300 was then electroplated to thicken it. The electroplating parameters were: plating speed of 1 m / min; the electroplating solution mainly consisted of 110 g / L anhydrous copper sulfate, 125 g / L sulfuric acid, 50 ppm chloride ions, 2 ml / L additive A, 0.2 ml / L additive B, and 2 ml / L additive C. The current during electroplating was 3043 A, and the maximum voltage of a single rectifier was ≤4 V. The resulting copper foil thickness was 15 μm. Then, an antioxidant layer 500 was deposited on the copper foil layer 400 using an antioxidant solution (1.75 g / L chromic anhydride, 22.5 g / L glucose), with a thickness of 8 nm. After copper plating on one side of the aluminum foil substrate 100, the above cleaning and antioxidant layer 500 plating steps were repeated to complete copper plating on the other side of the aluminum foil substrate 100. Among them, additive A is polyethylene glycol (PEG), additive B is sodium 3-mercaptopropanesulfonate (MPS), and additive C is polydiallyldimethylammonium chloride (polyDADMAC) (CAS 26062-79-3).
[0041] Example 4 This invention provides a method for preparing aluminum-based copper foil, which is the same as in Example 3, except that the electroplating parameters are: the plating speed is 2m / min.
[0042] Comparative Example 6 This invention provides a method for preparing aluminum-based copper foil, which is the same as in Example 3, except that the electroplating parameters are: the plating speed is 3m / min.
[0043] Performance Tests and Results The aluminum-based copper foil samples obtained in Examples 1-2 and Comparative Examples 1-5 were sampled and tested. The thickness of the seed copper layer 300 was measured using an energy dispersive X-ray spectrometer (model: EDX600PLUS). The copper thickness was measured as follows: Comparative Example 1: 59 nm; Comparative Example 2: 62 nm; Comparative Example 3: 65 nm; Comparative Example 4: 59 nm; Comparative Example 5: 58 nm; Example 1: 64 nm; Example 2: 60 nm. The adhesion between the samples of Example 1 and Comparative Examples 1-5 was tested using 3M 8915 tape. The seed copper layer 300 did not fall off in any of the samples.
[0044] The specific results of the film surface conditions of Examples 1-2 and Comparative Examples 1-5 during the magnetron sputtering stage are shown in Table 1. No thermal deformation was observed in Examples 1-2 and Comparative Examples 1-5. Comparative Examples 1-5 showed wrinkles, while Examples 1-2 did not. This indicates that the coating effect is optimal when the coating drum temperature is between 32-35℃, with no obvious wrinkles or thermal deformation on the film surface. The reason why no wrinkles or thermal deformation appeared in Examples 1-2 is that the film surface temperature is relatively high during magnetron sputtering. If the coating drum temperature is low, the temperature difference between the aluminum foil substrate 100 and the coating drum is large. Since the thermal expansion coefficients of aluminum and copper differ greatly, rapid cooling after coating causes wrinkles on the aluminum foil. Therefore, appropriately heating the coating drum actually helps improve the film surface condition.
[0045] Table 1
[0046] Various physical properties were tested on the samples obtained in Examples 3-4 and Comparative Example 6. The test results are shown in Table 2. In Examples 3-4, the copper foil was electroplated to a thickness of 15 μm at two different plating speeds. The cross-cut test all reached 5B. The 135-degree bending test had more than 40 horizontal and vertical cycles. The thickened copper foil did not blister or oxidize and discolor after baking at 160°C for 2 hours. However, the tensile strength and elongation were greatly affected by the aluminum foil substrate 100.
[0047] Table 2
[0048] Unless otherwise specified, all raw materials used in this invention are existing substances that can be purchased directly from the market.
[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing aluminum-based copper foil, characterized in that, Includes the following steps: S1. Obtain aluminum foil substrate; S2. Sputter coating is performed using a coating drum, wherein the temperature of the coating drum is set to 32-35℃; S3. After magnetron sputtering is completed, electroplating is performed on the magnetron sputtered aluminum foil substrate, wherein the plating speed is 1-2 m / min, to obtain aluminum-based copper foil.
2. The method for preparing aluminum-based copper foil according to claim 1, characterized in that, In step S1, after obtaining the aluminum foil substrate, it is first evacuated and cooled to the required temperature, and then plasma cleaned; and / or, In step S1, the thickness of the aluminum foil substrate is 9-200 μm.
3. The method for preparing aluminum-based copper foil according to claim 1, characterized in that, After step S1, before sputtering the aluminum foil substrate, an underlayer is first deposited, the material of which includes nickel-chromium or nickel.
4. The method for preparing aluminum-based copper foil according to claim 3, characterized in that, The thickness of the substrate after application is 10-50nm; and / or, The underlayer is deposited using argon as the sputtering gas.
5. The method for preparing aluminum-based copper foil according to claim 1, characterized in that, In step S2, the coating speed is 1-3 m / min, the sputtering power is 20-24 kW, the nickel-chromium target power is 1-2 kW, the argon flow rate of the ion source is 55 sccm, and the argon flow rate of the cathode is 50-80 sccm. In step S2, the thickness of the seed copper layer deposited by magnetron sputtering is 20-200 nm.
6. The method for preparing aluminum-based copper foil according to claim 1, characterized in that, In step S3, the electroplating coating will use an electroplating solution, which includes 110 g / L anhydrous copper sulfate, 125 g / L sulfuric acid, 50 ppm chloride ions, 2 ml / L wetting agent, 0.2 ml / L brightener, and 2 ml / L leveling agent.
7. The method for preparing aluminum-based copper foil according to claim 1, characterized in that, In step S3, the electroplating current is 3043-7985A, and the maximum voltage of a single rectifier is ≤4V.
8. The method for preparing aluminum-based copper foil according to claim 1, characterized in that, In step S3, an electroplating film is formed to form a copper foil layer with a thickness of 1-35 μm.
9. The method for preparing aluminum-based copper foil according to claim 8, characterized in that, The aluminum-based copper foil also includes an anti-oxidation layer covering the copper foil layer.
10. The method for preparing aluminum-based copper foil according to claim 9, characterized in that, The thickness of the antioxidant layer is 5-10 nm; The materials used to prepare the antioxidant layer include chromium anhydride and glucose.