A method for improving the surface quality of cold-rolled copper strip for integrated circuit framework materials

Abstract

This invention relates to the field of copper strip rolling technology, specifically a method for improving the surface quality of cold-rolled copper strip used as a frame material for integrated circuits. This method employs an air-cushion annealing furnace for annealing and cleaning the copper strip coil. The cleaning process includes: uncoiling → degreasing → first water wash → second water wash → pickling → third water wash → polishing → fourth water wash → passivation → drying → rewinding. Nylon brushes are selected for degreasing, and polishing employs a combination of pre-polishing and fine polishing. The pre-polishing brush uses a 2000-2500 mesh abrasive brush, and the fine polishing brush uses a 2500-3000 mesh abrasive brush. This method also improves the surface quality of C19400 copper alloy strip during the rolling process by ensuring the cleanliness of the cooling and lubricating medium and controlling the cold rolling process. Through these technical measures, the surface of the C19400 copper alloy strip after finished rolling is free of visible pits and bumps, meeting the surface quality requirements for subsequent processing of the copper strip.

Description

Technical Field

[0001] This invention relates to the field of copper strip rolling technology, specifically to a method for improving the surface quality of cold-rolled copper strip used as a material for integrated circuit frames. Background Technology

[0002] C19400 copper alloy is widely used in industries such as industry, aerospace, aviation, electronics, and power. With the rapid development of the copper alloy processing industry, the surface of C19400 copper alloy strip used for integrated circuit frame materials must have a bright, clean, flat, pollution-free, and corrosion-resistant surface quality to meet the process requirements of subsequent secondary processing such as electroplating and stamping. Surface quality control of copper alloy strip involves every stage of the entire production process, among which surface quality control during the finished product cold rolling process is a key step in improving the surface quality of the strip.

[0003] The finished product cold rolling production uses a six-roll reversible cold rolling mill with rolling oil as the lubricating medium. The cold rolling process is controlled using conventional methods. Conventional cold rolling methods do not trim the edges before pre-finished product annealing, resulting in more burrs on the edges. Pre-finished product annealing often uses a bell-type annealing furnace, which easily leads to carbon black and other contaminants adhering to the surface after exiting the furnace. Furthermore, there are only 1-2 passes of the squeeze rolls, resulting in slightly poor oil removal. Traditional cold rolling oil only has one filtration stage, and the particle size of the filtered rolling oil is often above NAS 8. This conventional cold rolling method frequently produces visible surface pits and bumps, severely affecting the surface quality of subsequent electroplating processes. Summary of the Invention

[0004] To address the problem of surface defects that easily occur when C19400 copper alloy is cold rolled using conventional methods, this invention provides a method for improving the surface quality of cold-rolled copper strips used as integrated circuit frame materials. By adopting technical measures, the surface of the finished C19400 copper alloy after cold rolling is free of pits and bumps visible to the naked eye, thus meeting the surface quality requirements for subsequent processing of the copper strip.

[0005] This invention is achieved using the following technical solution: a method for improving the surface quality of cold-rolled copper strip used in integrated circuit frame materials, comprising the following steps:

[0006] (1) Before annealing the pre-finished copper strip roll, cut the edges 3-5mm on each side to ensure that the edges are neat, clean, and free of visible burrs and gaps.

[0007] (2) The pre-finished copper strip coil annealing production adopts an air cushion annealing furnace, which includes annealing and cleaning steps. Cleaning steps: uncoiling → degreasing (degreasing brush) → first water wash → second water wash → pickling → third water wash → polishing → fourth water wash → passivation → drying → coiling. Among them, nylon brushes are selected for degreasing, and the degreasing brushes are installed in the cleaning box used to hold the degreasing solution. Polishing adopts pre-polishing + fine polishing. The pre-polishing brush is a 2000-2500 mesh abrasive brush, and the fine polishing brush is a 2500-3000 mesh abrasive brush. The pre-polishing brush and the fine polishing brush are installed in the brush box on the machine for polishing in the order of brushing. Passivation solution concentration: 0.10~0.12%. Surface quality of copper strip coil after cleaning: the copper strip surface is clean under naked eye, free of carbon black, copper powder and other foreign matter.

[0008] (3) The finished product cold rolling production adopts a six-roll reversible cold rolling mill with an inlet thickness of 0.15mm-0.5mm and a material width of 350mm-420mm.

[0009] (4) During the six-roll finishing process, there are 3 pairs of extrusion rolls on the left and right exit sides to remove oil. The replacement cycle of the extrusion rolls is set to 6-8 months under continuous production.

[0010] (5) Before the six-roll precision rolling process, the outermost ring of the incoming material coil is cut off.

[0011] (6) The rolling oil of the six-roll finishing mill adopts double-layer filtration. The first layer of filtration adopts plate filtration and the second layer of filtration adopts bag filtration. The particle size of the rolling oil is controlled at NAS7-NAS8 level.

[0012] (7) During the six-roll finishing process, rolling oil is used for lubrication and cooling, and double-sided spraying is adopted at the inlet and outlet, with the spray flow rate controlled at 300-360L / min.

[0013] (8) The rolling oil should be added in small amounts and multiple times, once a week, with the amount added controlled between 300kg and 450kg.

[0014] (9) The roughness of the support roller Ra is 0.7μm~0.9μm, the roughness of the intermediate roller Ra is 0.3μm~0.6μm, and the roughness of the working roller Ra is 0.08μm-0.12μm.

[0015] (10) The cold rolling processing rate of each pass is controlled at 20% to 25%, and the exit thickness after rolling is 0.1 mm to 0.3 mm.

[0016] This invention improves the surface quality of C19400 copper alloy strip during the rolling process by ensuring the cleanliness of the cooling and lubricating medium and controlling the cold rolling process, thus meeting the quality requirements of subsequent electroplating. Verification of the finished product: The copper strip surface is observed with the naked eye and shows no visible pits or bumps, meeting the surface quality requirements for subsequent electroplating.

[0017] The purpose of this invention is to improve the cleanliness of the rolling oil during the cold rolling process of C19400 copper alloy strip in the finished product cold rolling mill by taking the above technical measures. Measures are taken in terms of fixed addition cycle, filtration requirements and process control to ensure that there are no visible pits or bumps on the surface of the strip after rolling, so as to meet the quality requirements of subsequent processing. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the embodiments. Example

[0019] A method for improving the surface quality of cold-rolled copper strip used as a framework material for integrated circuits includes the following steps:

[0020] (1) Before annealing the pre-finished copper strip roll, cut the edges by 3mm on each side to ensure that the edges are neat, smooth, and free of visible burrs and gaps.

[0021] (2) The pre-finished copper strip coil annealing production adopts an air-cushion annealing furnace, which includes annealing and cleaning steps. Cleaning steps: uncoiling → degreasing (degreasing brush) → first water wash → second water wash → pickling → third water wash → polishing → fourth water wash → passivation → drying → rewinding. Among them, nylon brushes are selected for degreasing, and the degreasing brushes are installed in the cleaning box used to hold the degreasing solution. Polishing adopts pre-polishing + fine polishing. The pre-polishing brush is a 2000-mesh abrasive brush, and the fine polishing brush is a 2500-mesh abrasive brush. The pre-polishing brush and the fine polishing brush are installed in the brush box for polishing on the machine in the order of brushing. The concentration of BTA (benzotriazole) passivation solution is 0.10%.

[0022] (3) The finished product cold rolling production adopts a six-roll reversible cold rolling mill with an inlet thickness of 0.15mm and a material width of 350mm.

[0023] (4) During the six-roll finishing process, there are 3 pairs of extrusion rolls on both the left and right exit sides for oil removal. The replacement cycle of the extrusion rolls is set to 6 months under continuous production.

[0024] (5) Before the six-roll precision rolling process, the outermost ring of the incoming material coil is cut off.

[0025] (6) The rolling oil of the six-roll finishing mill adopts double-layer filtration. The first layer of filtration adopts plate filtration and the second layer of filtration adopts bag filtration. The particle size of the rolling oil is NAS 7 grade.

[0026] (7) Rolling oil is used for lubrication and cooling during the six-roll finishing process, and double-sided spraying is used at the inlet and outlet, with the spray flow rate controlled at 300L / min.

[0027] (8) Rolling oil should be added in small amounts and multiple times, once a week, with the amount added controlled at 300 kg. The rolling mill stand should be cleaned regularly, and thoroughly cleaned and wiped once a week.

[0028] (9) The roughness of the support roller Ra is 0.7μm, the roughness of the intermediate roller Ra is 0.3μm, and the roughness of the working roller Ra is 0.08μm.

[0029] (10) The cold rolling processing rate of each pass is controlled at around 25%, and the exit thickness after rolling is 0.1 mm.

[0030] Finished product effect verification: The surface of the copper strip is observed with the naked eye and there are no pits or bumps visible to the naked eye, which meets the surface quality requirements of subsequent electroplating processing. Example

[0031] A method for improving the surface quality of cold-rolled copper strip used as a framework material for integrated circuits includes the following steps:

[0032] (1) Before annealing the pre-finished copper strip coil, cut 5mm on each side to ensure that the edges are neat, clean, and free of visible burrs and gaps.

[0033] (2) The pre-finished copper strip coil annealing production adopts an air-cushion annealing furnace, which includes annealing and cleaning steps. Cleaning steps: uncoiling → degreasing (degreasing brush) → first water wash → second water wash → pickling → third water wash → polishing → fourth water wash → passivation → drying → rewinding. Among them, nylon brushes are selected for degreasing, and the degreasing brushes are installed in the cleaning box used to hold the degreasing solution. Polishing adopts pre-polishing + fine polishing. The pre-polishing brush is a 2500-mesh abrasive brush, and the fine polishing brush is a 3000-mesh abrasive brush. The pre-polishing brush and the fine polishing brush are installed in the brush box for polishing on the machine in the order of brushing. The BTA (benzotriazole) concentration is 0.12%.

[0034] (3) The finished product cold rolling production adopts a six-roll reversible cold rolling mill with an inlet thickness of 0.5mm and a material width of 420mm.

[0035] (4) During the six-roll finishing process, there are 3 pairs of extrusion rolls on both the left and right exit sides to remove oil. The replacement cycle of the extrusion rolls is set to 8 months under continuous production.

[0036] (5) Before the six-roll precision rolling process, the outermost ring of the incoming material coil is cut off.

[0037] (6) The rolling oil of the six-roll finishing mill adopts double-layer filtration. The first layer of filtration adopts plate filtration and the second layer of filtration adopts bag filtration. The particle size of the rolling oil is NAS 8 grade.

[0038] (7) During the six-roll finishing process, rolling oil is used for lubrication and cooling, and double-sided spraying is adopted at the inlet and outlet, with the spray flow rate controlled at 360L / min.

[0039] (8) Rolling oil should be added in small amounts and multiple times, once a week, with the amount added controlled at 450 kg. The rolling mill stand should be cleaned regularly, and thoroughly cleaned and wiped once a week.

[0040] (9) The roughness of the support roller is Ra 0.9μm, the roughness of the intermediate roller is Ra 0.6μm, and the roughness of the working roller is Ra 0.12μm.

[0041] (10) The cold rolling processing rate of each pass is controlled at around 20%, and the exit thickness after rolling is 0.2 mm.

[0042] Finished product effect verification: The surface of the copper strip is observed with the naked eye and there are no pits or bumps visible to the naked eye, which meets the surface quality requirements of subsequent electroplating processing. Example

[0043] A method for improving the surface quality of cold-rolled copper strip used as a framework material for integrated circuits includes the following steps:

[0044] (1) Before annealing the pre-finished copper strip coil, cut the edges by 4mm on each side to ensure that the edges are neat, smooth, and free of visible burrs and gaps.

[0045] (2) The pre-finished copper strip coil annealing production adopts an air-cushion annealing furnace, which includes annealing and cleaning steps. Cleaning steps: uncoiling → degreasing (degreasing brush) → first water wash → second water wash → pickling → third water wash → polishing → fourth water wash → passivation → drying → rewinding. Among them, nylon brushes are selected for degreasing, and the degreasing brushes are installed in the cleaning box used to hold the degreasing solution. Polishing adopts pre-polishing + fine polishing. The pre-polishing brush is a 2000-mesh abrasive brush, and the fine polishing brush is a 3000-mesh abrasive brush. The pre-polishing brush and the fine polishing brush are installed in the brush box on the machine line for polishing in the order of brushing. BTA (benzotriazole) passivation solution concentration: 0.112%.

[0046] (3) The finished product cold rolling production adopts a six-roll reversible cold rolling mill with an inlet thickness of 0.35mm and a material width of 390mm.

[0047] (4) During the six-roll finishing process, there are 3 pairs of extrusion rolls on the left and right exit sides to remove oil. The replacement cycle of the extrusion rolls is 7 months of continuous production.

[0048] (5) Before the six-roll precision rolling process, the outermost ring of the incoming material coil is cut off.

[0049] (6) The rolling oil of the six-roll finishing mill adopts double-layer filtration. The first layer of filtration adopts plate filtration and the second layer of filtration adopts bag filtration. The particle size of the rolling oil is controlled at NAS 7 level.

[0050] (7) During the six-roll finishing process, rolling oil is used for lubrication and cooling, and double-sided spraying is adopted at the inlet and outlet, with the spray flow rate controlled at 345L / min.

[0051] (8) Rolling oil should be added in small amounts and multiple times, once a week, with the amount added controlled at 380 kg. The rolling mill stand should be cleaned regularly, and thoroughly cleaned and wiped once a week.

[0052] (9) The roughness of the support roller Ra is 0.82μm, the roughness of the intermediate roller Ra is 0.35μm, and the roughness of the working roller Ra is 0.095μm.

[0053] (10) The cold rolling rate of each pass is controlled at around 22%, and the exit thickness after rolling is 0.12 mm.

[0054] Finished product effect verification: The surface of the copper strip is observed with the naked eye and there are no pits or bumps visible to the naked eye, which meets the surface quality requirements of subsequent electroplating processing.

Claims

1. A method of improving the surface quality of a copper strip for cold rolling of integrated circuit frame materials, characterized by: Includes the following steps: (1) Before annealing the pre-finished copper strip coil, cut the edges by 3-5mm on each side; (2) The pre-finished copper strip coil annealing production adopts an air cushion annealing furnace, including annealing and cleaning steps; the cleaning steps are: uncoiling → degreasing → first water wash → second water wash → pickling → third water wash → polishing → fourth water wash → passivation → drying → rewinding. (3) The finished product cold rolling production adopts a six-roll reversible cold rolling mill for six-roll finishing rolling; during the six-roll finishing rolling process, squeeze rolls are provided on both the left and right exit sides for oil removal; the six-roll finishing rolling oil adopts double-layer filtration, the first layer of filtration adopts plate filtration, and the second layer of filtration adopts bag filtration, and the particle size of the rolling oil is controlled at NAS7-NAS8 grade; during the six-roll finishing rolling process, rolling oil is used for lubrication and cooling, and double-sided spraying is adopted at the inlet and outlet, and the spray flow rate is controlled at 300-360L / min; in the six-roll reversible cold rolling mill, the roughness of the support roll Ra is 0.7μm-0.9μm, the roughness of the intermediate roll Ra is 0.3μm-0.6μm, and the roughness of the work roll Ra is 0.08μm-0.12μm; the cold rolling processing rate per pass is controlled at 20%-25%; The six-roll reversible cold rolling mill has three pairs of extrusion rolls on the left and right exit sides for oil removal. The replacement cycle of the extrusion rolls is set to 6-8 months under continuous production. Rolling oil is added in small amounts and multiple times, once a week, with the amount added controlled at 300kg-450kg.

2. The method for improving the surface quality of a copper strip for integrated circuit frame materials according to claim 1, characterized by: In the cleaning process, nylon brushes are selected for the degreasing process, and the degreasing brushes are installed in the cleaning tank for holding the degreasing solution. Polishing adopts pre-polishing + fine polishing. The pre-polishing brush is a 2000-2500 mesh abrasive brush, and the fine polishing brush is a 2500-3000 mesh abrasive brush. The pre-polishing brush and the fine polishing brush are installed in the brush box for polishing on the machine in the order of brushing. The passivation solution concentration is 0.10-0.12%.

3. A method for improving the surface quality of cold-rolled copper strip for integrated circuit frame materials according to claim 1 or 2, characterized in that: The six-roll reversible cold rolling mill has an inlet thickness of 0.15mm-0.5mm, a feed width of 350mm-420mm, and an outlet thickness of 0.1mm-0.3mm after rolling.

4. A method for improving the surface quality of cold-rolled copper strip for integrated circuit frame materials according to claim 1 or 2, characterized in that: Before the six-roll precision rolling process, the outermost ring of the incoming material coil is cut off.

5. A method for improving the surface quality of cold-rolled copper strip for integrated circuit frame materials according to claim 1 or 2, characterized in that: The copper alloy grade used to make copper strip coils is C19400.