Production method of aluminum foil base material for copper plating of PCB copper-aluminum composite foil

Abstract

The invention provides a production method of an aluminum foil base material for copper plating of a PCB (Printed Circuit Board) copper-aluminum composite foil, which comprises the following steps of: (1) sequentially carrying out smelting and cast rolling procedures on an aluminum alloy to obtain a blank with the thickness of 6-7mm; (2) the blank is cold-rolled to 3-4 mm, and then the annealing procedure is conducted; in the annealing process, the temperature is increased to 100-120 DEG C firstly, heat preservation is conducted for 6-12 h, then the temperature is increased to 500-600 DEG C within 30-60 min, and heat preservation is conducted for 2-6 h; (3) continuously carrying out cold rolling until the thickness is 0.5-1 mm, and then carrying out an annealing process; in the annealing process, the temperature is increased to 320-400 DEG C firstly, and then heat preservation is conducted for 3-5 h; and (4) continuously carrying out cold rolling until the thickness is 0.02-0.4 mm, and then carrying out withdrawal and straightening and slitting processes to obtain the aluminum foil base material. The aluminum foil base material produced by the production method of the aluminum foil base material for copper plating of the PCB copper-aluminum composite foil is good in surface quality, few in pinholes and suitable for producing the PCB copper-aluminum composite foil.

Description

Technical Field

[0001] The invention relates to a method for producing an aluminum foil, and in particular to a method for producing an aluminum foil substrate for copper plating of a PCB copper-aluminum composite foil. Background Art

[0002] PCB, also known as printed circuit board, is an important electronic component, a support for electronic components, and a carrier for electrical connection of electronic components. Aluminum foil is widely used on various circuit boards due to its excellent performance in electromagnetic shielding, heat conduction and heat dissipation, and current collector. At present, there are many aluminum foil production processes on the market. For example: Chinese patent CN104550235A discloses a method for preparing aluminum foil for PCB using cast and rolled billets, and Chinese patent CN116637933A discloses a production process for thick aluminum foil for PCB.

[0003] In the field of electronic applications, in order to increase the conductivity and weldability of aluminum, it is necessary to electroplate copper, tin and other metals on its surface. However, the existing aluminum foil production process results in many pinholes in the aluminum foil substrate, poor surface quality, and serious quality problems in subsequent copper-aluminum composite foils.

[0004] In order to solve the above problems, people have been seeking an ideal technical solution. Summary of the invention

[0005] The purpose of the present invention is to provide a method for producing an aluminum foil substrate for copper plating of a PCB copper-aluminum composite foil in view of the deficiencies in the prior art.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: A method for producing an aluminum foil substrate for copper plating of a PCB copper-aluminum composite foil comprises the following steps: (1) The aluminum alloy is subjected to smelting and casting and rolling processes in sequence to obtain a billet with a thickness of 6-7 mm; (2) After the billet is cold rolled to 3-4 mm, an annealing process is performed; in the annealing process, the temperature is first raised to 100-120°C, kept at this temperature for 6-12 h, then raised to 500-600°C within 30-60 min, and kept at this temperature for another 2-6 h; (3) Continue cold rolling to a thickness of 0.5-1 mm and then perform annealing. During the annealing process, first heat to 320-400°C and then keep warm for 3-5 hours. (4) Continue cold rolling to a thickness of 0.02-0.4 mm, and then perform straightening and slitting processes to obtain an aluminum foil substrate.

[0007] The aluminum alloy components are: Si: 0.04-0.25%, Fe: 0.25-0.45%, Cu: 0.01-0.05%, Mn: 0-0.01%, Mg: 0.005-0.02%, Zn: 0-0.01%, Ti: 0.001-0.03%, and the balance is aluminum; the sum of the above components is 100%.

[0008] The roughness of the casting roll is 0.8-1.2 μm; the roughness of the first cold rolling roll is 0.65-0.75 μm; the roughness of the second cold rolling roll is 0.3-0.6 μm; and the roughness of the third cold rolling roll is 0.15-0.25 μm.

[0009] The casting and rolling process includes four rolling passes. The rolling force of the first pass is 400-600KN, the rolling force of the second pass is 700-900KN; the rolling force of the third pass is 800-1000KN, and the rolling force of the fourth pass is 1000-1200KN; the rolling speed of the casting and rolling process is 500-700 m / min.

[0010] In the first cold rolling process, the rolling force is 1000-1200 KN and the rolling speed is 600-800 m / min.

[0011] In the second cold rolling process, the rolling force is 1200-1300 KN and the rolling speed is 600-800 m / min.

[0012] In the third cold rolling process, the rolling force is 1200-1600 KN and the rolling speed is 600-800 m / min.

[0013] The present invention has outstanding substantive features and significant progress compared to the prior art. Specifically, the present invention provides a method for producing an aluminum foil substrate for copper plating of PCB copper-aluminum composite foil. The aluminum foil substrate produced by the method has good surface quality and few pinholes, and is suitable for producing PCB copper-aluminum composite foil. Specifically, by optimizing the annealing process and the cold rolling process, the metals are evenly dispersed, the precipitation of impurities in the aluminum foil is promoted, the number of pinholes on the surface of the aluminum foil is reduced, and an aluminum foil substrate with a good surface is obtained. DETAILED DESCRIPTION

[0014] The technical solution of the present invention is further described in detail below through specific implementation methods.

[0015] Example 1 A method for producing an aluminum foil substrate for copper plating of a PCB copper-aluminum composite foil comprises the following steps: (1) The aluminum alloy is subjected to smelting and casting and rolling processes in sequence to obtain a billet with a thickness of 7 mm; the casting and rolling process includes four rolling passes, the rolling force of the first pass is 400 KN, the rolling force of the second pass is 700 KN, the rolling force of the third pass is 800 KN, and the rolling force of the fourth pass is 1000 KN; the rolling speed of the casting and rolling process is 500 m / min; the roughness of the casting and rolling roller is 0.8 μm. The aluminum alloy components are: Si: 0.04-0.25%, Fe: 0.25-0.45%, Cu: 0.01-0.05%, Mn: 0-0.01%, Mg: 0.005-0.02%, Zn: 0-0.01%, Ti: 0.001-0.03%, and the balance is aluminum; the sum of the above components is 100%.

[0016] (2) After the billet is cold rolled to 3 mm, an annealing process is performed; the roughness of the cold rolling roller is 0.65 μm, the rolling force is 1000 KN, and the rolling speed is 600 m / min; in the annealing process, the temperature is first raised to 100-120 °C and kept at this temperature for 6 h, then raised to 500-600 °C within 30 min, and kept at this temperature for another 2 h; (3) Continue cold rolling to a thickness of 0.5 mm and then perform annealing. The roughness of the cold rolling roller is 0.6 μm, the rolling force is 1200 KN, and the rolling speed is 600 m / min. During the annealing process, the temperature is first raised to 320-400 °C and then kept at this temperature for 3 h. (4) Continue cold rolling to a thickness of 0.02 mm, the roughness of the cold rolling roller is 0.15 μm, the rolling force is 1600 KN, the rolling speed is 800 m / min, and then the straightening and slitting processes are performed to obtain the aluminum foil substrate. The number of A-level pinholes on the surface of the aluminum foil substrate is 42 / 100 m 2 ; The number of A-level pinholes on the surface of the aluminum foil substrate is 23 / 100m 2 .

[0017] Example 2 A method for producing an aluminum foil substrate for copper plating of a PCB copper-aluminum composite foil comprises the following steps: (1) The aluminum alloy is subjected to smelting and casting and rolling processes in sequence to obtain a billet with a thickness of 6 mm; the casting and rolling process includes four rolling passes, the rolling force of the first pass is 500 KN, the rolling force of the second pass is 700 KN, the rolling force of the third pass is 1000 KN, and the rolling force of the fourth pass is 1200 KN; the rolling speed of the casting and rolling process is 700 m / min; the roughness of the casting and rolling roller is 1.2 μm. The aluminum alloy components are: Si: 0.04-0.25%, Fe: 0.25-0.45%, Cu: 0.01-0.05%, Mn: 0-0.01%, Mg: 0.005-0.02%, Zn: 0-0.01%, Ti: 0.001-0.03%, and the balance is aluminum; the sum of the above components is 100%.

[0018] (2) After the billet is cold rolled to 4 mm, an annealing process is performed; the roughness of the cold rolling roller is 0.65 μm, the rolling force is 1200 KN, and the rolling speed is 600 m / min; in the annealing process, the temperature is first raised to 100-120°C and kept at this temperature for 12 h, then raised to 500-600°C within 60 min, and kept at this temperature for another 6 h; (3) Continue cold rolling to a thickness of 1 mm and then perform annealing; the roughness of the cold rolling roller is 0.6 μm, the rolling force is 1200 KN, and the rolling speed is 600 m / min; during the annealing process, first heat up to 320-400 °C and then keep warm for 5 h; (4) Continue cold rolling to a thickness of 0.4 mm, the roughness of the cold rolling roller is 0.25 μm, the rolling force is 1200 KN, the rolling speed is 600 m / min, and then the straightening and slitting processes are performed to obtain the aluminum foil substrate. The number of A-level pinholes on the surface of the aluminum foil substrate is 49 / 100 m 2 ; The number of A-level pinholes on the surface of the aluminum foil substrate is 27 / 100m 2 .

[0019] Example 3 A method for producing an aluminum foil substrate for copper plating of a PCB copper-aluminum composite foil comprises the following steps: (1) The aluminum alloy is subjected to smelting and casting and rolling processes in sequence to obtain a billet with a thickness of 6.5 mm; the casting and rolling process includes four rolling passes, the rolling force of the first pass is 400 KN, the rolling force of the second pass is 900 KN, the rolling force of the third pass is 900 KN, and the rolling force of the fourth pass is 1200 KN; the rolling speed of the casting and rolling process is 700 m / min; the roughness of the casting and rolling roller is 1.2 μm. The aluminum alloy components are: Si: 0.04-0.25%, Fe: 0.25-0.45%, Cu: 0.01-0.05%, Mn: 0-0.01%, Mg: 0.005-0.02%, Zn: 0-0.01%, Ti: 0.001-0.03%, and the balance is aluminum; the sum of the above components is 100%.

[0020] (2) After the billet is cold rolled to 3 mm, an annealing process is performed; the roughness of the cold rolling roller is 0.70 μm, the rolling force is 1200 KN, and the rolling speed is 600 m / min; in the annealing process, the temperature is first raised to 100-120 °C and kept at this temperature for 8 h, then raised to 500-600 °C within 30 min, and kept at this temperature for another 4 h; (3) Continue cold rolling to a thickness of 0.5 mm and then perform annealing. The roughness of the cold rolling roller is 0.4 μm, the rolling force is 1200 KN, and the rolling speed is 600 m / min. During the annealing process, the temperature is first raised to 320-400 °C and then kept at this temperature for 4 h. (4) Continue cold rolling to a thickness of 0.05 mm, the roughness of the cold rolling roller is 0.15 μm, the rolling force is 1300 KN, the rolling speed is 800 m / min, and then the straightening and slitting processes are performed to obtain the aluminum foil substrate. The number of A-level pinholes on the surface of the aluminum foil substrate is 38 / 100 m 2 ; The number of Class A pinholes on the surface of the aluminum foil substrate is 16 / 100m 2 .

[0021] Example 4 A method for producing an aluminum foil substrate for copper plating of a PCB copper-aluminum composite foil comprises the following steps: (1) The aluminum alloy is subjected to smelting and casting and rolling processes in sequence to obtain a billet with a thickness of 6 mm; the casting and rolling process includes four rolling passes, the rolling force of the first pass is 400 KN, the rolling force of the second pass is 800 KN, the rolling force of the third pass is 900 KN, and the rolling force of the fourth pass is 1200 KN; the rolling speed of the casting and rolling process is 500 m / min; the roughness of the casting and rolling roller is 0.8 μm. The aluminum alloy components are: Si: 0.04-0.25%, Fe: 0.25-0.45%, Cu: 0.01-0.05%, Mn: 0-0.01%, Mg: 0.005-0.02%, Zn: 0-0.01%, Ti: 0.001-0.03%, and the balance is aluminum; the sum of the above components is 100%.

[0022] (2) After the billet is cold rolled to 3 mm, an annealing process is performed; the roughness of the cold rolling roller is 0.65 μm, the rolling force is 1200 KN, and the rolling speed is 600 m / min; in the annealing process, the temperature is first raised to 100-120°C and kept at this temperature for 10 h, then raised to 500-600°C within 50 min, and kept at this temperature for another 5 h; (3) Continue cold rolling to a thickness of 0.7 mm and then perform annealing. The roughness of the cold rolling roller is 0.4 μm, the rolling force is 1200 KN, and the rolling speed is 700 m / min. During the annealing process, the temperature is first raised to 320-400 °C and then kept at this temperature for 5 h. (4) Continue cold rolling to a thickness of 0.02-0.4 mm, the roughness of the cold rolling roller is 0.15-0.25 μm, the rolling force is 1200-1600 KN, the rolling speed is 600-800 m / min, and then the straightening and slitting processes are performed to obtain the aluminum foil substrate. The number of A-level pinholes on the surface of the aluminum foil substrate is 35 / 100 m 2 ; The number of A-level pinholes on the surface of the aluminum foil substrate is 14 / 100m 2 .

[0023] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A method for producing an aluminum foil substrate for copper plating of a PCB copper-aluminum composite foil, comprising the following steps: (1) The aluminum alloy is subjected to smelting and casting and rolling processes in sequence to obtain a billet with a thickness of 6-7 mm; (2) After the billet is cold rolled to 3-4 mm, an annealing process is performed; in the annealing process, the temperature is first raised to 100-120°C, kept at this temperature for 6-12 hours, then raised to 500-600°C within 30-60 minutes, and kept at this temperature for another 2-6 hours; (3) Continue cold rolling to a thickness of 0.5-1 mm and then perform annealing. During the annealing process, first heat to 320-400°C and then keep warm for 3-5 hours. (4) Continue cold rolling to a thickness of 0.02-0.4 mm, and then perform straightening and slitting processes to obtain an aluminum foil substrate.

2. The method for producing an aluminum foil substrate for copper plating of a PCB copper-aluminum composite foil according to claim 1, characterized in that: The aluminum alloy components are: Si: 0.04-0.25%, Fe: 0.25-0.45%, Cu: 0.01-0.05%, Mn: 0-0.01%, Mg: 0.005-0.02%, Zn: 0-0.01%, Ti: 0.001-0.03%, and the balance is aluminum; the sum of the above components is 100%.

3. The method for producing an aluminum foil substrate for copper plating of a PCB copper-aluminum composite foil according to claim 2, characterized in that: The roughness of the casting roll is 0.8-1.2 μm; the roughness of the first cold rolling roll is 0.65-0.75 μm; the roughness of the second cold rolling roll is 0.3-0.6 μm; and the roughness of the third cold rolling roll is 0.15-0.25 μm.

4. The method for producing an aluminum foil substrate for copper plating of a PCB copper-aluminum composite foil according to claim 3, characterized in that: The casting and rolling process includes four rolling passes. The rolling force of the first pass is 400-600KN, the rolling force of the second pass is 700-900KN; the rolling force of the third pass is 800-1000KN, and the rolling force of the fourth pass is 1000-1200KN; the rolling speed of the casting and rolling process is 500-700 m / min.

5. The method for producing an aluminum foil substrate for copper plating of a PCB copper-aluminum composite foil according to claim 4, characterized in that: In the first cold rolling process, the rolling force is 1000-1200 KN and the rolling speed is 600-800 m / min.

6. The method for producing an aluminum foil substrate for copper plating of a PCB copper-aluminum composite foil according to claim 5, characterized in that: In the second cold rolling process, the rolling force is 1200-1300 KN and the rolling speed is 600-800 m / min.

7. The method for producing an aluminum foil substrate for copper plating of a PCB copper-aluminum composite foil according to claim 6, characterized in that: In the third cold rolling process, the rolling force is 1200-1600 KN and the rolling speed is 600-800 m / min.