Process for the production of sintered nickel layer on aluminum sheet

Abstract

The application discloses a production process of an aluminum sheet sintered nickel layer, and comprises the following steps: S1, preparing nickel slurry: uniformly mixing nano nickel powder, resin and a binder to obtain the nickel slurry; S2, uniformly applying the nickel slurry on the surface of the aluminum sheet by a silk printing process; S3, primary sintering: heating the aluminum sheet coated with the nickel slurry by using a laser with a continuous power of 15W to 250W; and S4, secondary sintering: again heating the aluminum sheet coated with the nickel slurry by using a laser with a continuous power of 200W to 500W, so as to prepare the aluminum sheet with the nickel layer, which can be directly tin-plated, and the application range of the aluminum sheet is expanded.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum sheet welding, in particular to a production process of an aluminum sheet sintered nickel layer. Background Art

[0002] Currently, nickel-plated aluminum is used for soldering aluminum foil in automotive FPCs (Flexible Printed Circuits). However, the soldering area is often limited to a small, localized area. However, the production process for nickel-plated aluminum dictates that nickel plating cannot be performed on the entire raw material, requiring only the entire material to be nickel-plated. This results in significant resource waste and increased production costs.

[0003] Furthermore, the existing electroless plating process is the primary method for producing nickel-plated aluminum. This process utilizes a strong reducing agent in a solution containing metal ions to reduce them to metal, which is then deposited on the surface of various materials to form a dense coating. However, electroless nickel plating is a highly polluting, energy-intensive, and inefficient surface treatment process. Furthermore, due to its limited process flexibility and low efficiency, it is not suitable for use in high-tech, fully automated production lines. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings, the purpose of the present invention is to provide a production process for sintering a nickel layer on an aluminum sheet, so as to prepare an aluminum sheet with a nickel layer, which can be directly tinned and soldered.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0006] A production process for a sintered nickel layer on an aluminum sheet comprises the following steps:

[0007] S1. Prepare nickel slurry: mix nano nickel powder, resin and binder evenly to obtain nickel slurry;

[0008] S2. Applying nickel paste: Apply the nickel paste obtained in S1 evenly on the surface of the aluminum sheet through a silk screen printing process;

[0009] S3, primary sintering: using a laser with a continuous power of 15W to 250W to heat the aluminum sheet coated with nickel paste, leaving nano nickel powder covering the aluminum sheet;

[0010] S4. Secondary sintering: Use a laser with a continuous power of 200W to 500W to sinter the surface of the aluminum sheet with nano-nickel powder again.

[0011] Furthermore, in the above-mentioned production process of the aluminum sheet sintered nickel layer, the content of nano nickel powder in the nickel slurry exceeds 50%.

[0012] Furthermore, in the above-mentioned production process of the aluminum sheet sintered nickel layer, the coating thickness of the nickel paste is 0.1 to 0.3 mm.

[0013] Furthermore, in the above-mentioned production process of the aluminum sheet sintered nickel layer, the laser is a CO2 laser or a fiber laser.

[0014] Furthermore, in the above-mentioned production process of the aluminum sheet sintered nickel layer, in step S3, the defocus of the laser is +2 to +8 mm, the galvanometer speed is 200 to 1500 mm / s, and the image straight line filling interval is 0.07 to 0.3 mm.

[0015] Furthermore, in the above-mentioned production process of the sintered nickel layer on the aluminum sheet, in step S3, the power of the laser is 200 W, the defocus amount is +5 mm, the galvanometer speed is 900 mm / s, and the image straight line filling interval is 0.15 mm.

[0016] Furthermore, in the above-mentioned production process of the aluminum sheet sintered nickel layer, in step S3, the heating temperature of the nickel paste is 250-550°C.

[0017] Furthermore, in the above-mentioned production process of the aluminum sheet sintered nickel layer, in step S4, the defocus of the laser is +1 to +7 mm, the galvanometer speed is 150 to 350 mm / s, and the image straight line filling interval is 0.06 to 0.2 mm.

[0018] Furthermore, in the above-mentioned production process of the sintered nickel layer on the aluminum sheet, in step S4, the power of the laser is 300 W, the defocus amount is +5.5 mm, the galvanometer speed is 250 mm / s, and the image straight line filling interval is 0.15 mm.

[0019] Furthermore, in the above-mentioned production process of the aluminum sheet sintered nickel layer, in step S3, the heating temperature of the nickel paste exceeds 1453°C.

[0020] The beneficial effects of the present invention are:

[0021] (1) The laser sintering process uses laser equipment as a carrier, which is highly flexible and automated, and is very conducive to integration into a fully automated production line;

[0022] (2) Laser sintering technology has low pollution, low energy consumption, high efficiency, saving a lot of production costs and social resources;

[0023] (3) Compared with copper, aluminum has a lighter density and lower cost. Aluminum sheets with a nickel layer can be directly tinned, which will promote the application of aluminum in the new energy industry and is of great significance to reducing industry costs. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present invention are described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0025] Example 1

[0026] A production process for a sintered nickel layer on an aluminum sheet comprises the following steps:

[0027] S1. Prepare nickel slurry: Mix nano nickel powder (CAS registration number: 7440-02-0), resin and binder to obtain nickel slurry, wherein the nano nickel powder accounts for more than 50%, and the resin and binder can be purchased from outside;

[0028] S2. Apply nickel paste: Apply the nickel paste obtained in S1 evenly to the surface of the aluminum sheet by silk screen printing. The thickness of the nickel paste is 0.1 to 0.3 mm. The nickel paste can be applied locally or all over the aluminum sheet. Silk screen printing can be performed on the locations where soldering connection is actually required.

[0029] S3. Single sintering: Use a CO2 laser or fiber laser with a continuous power of 15W to 250W to irradiate the aluminum sheet coated with nickel paste; the laser uses a defocus of +2 to +8mm or a multi-mode spot to enable the laser to heat the resin and binder in the nickel paste. The galvanometer speed is set between 200mm / s and 1500mm / s, the image straight line fill interval is between 0.07mm and 0.3mm, and the temperature is controlled between 250℃ and 550℃. The resin and other non-metallic components in the nickel paste will be quickly decomposed and volatilized. The melting point of nickel is above 1453℃, and finally, nano-nickel powder is left covering the aluminum surface.

[0030] S4. Secondary sintering: Use a CO2 laser or fiber laser again with a continuous power of 200W to 500W to irradiate the surface of the aluminum sheet with nano-nickel powder. In order to quickly raise the heating temperature to above the melting point of nickel 1453℃, the defocus of the laser is +1 to +7mm, which can obtain a relatively high energy density. In addition, the melting point of aluminum is only 660℃, which is far lower than the melting point of nickel. In order to avoid large deformation of the aluminum sheet caused by high-temperature heating, the galvanometer speed is set at 150mm / s to 350mm / s. When the image linear filling interval is 0.06mm to 0.2mm, the temperature of the nano-nickel powder on the surface of the aluminum sheet quickly rises to above the melting point of nickel, and is transferred from the upper layer of nano-nickel powder to the aluminum sheet, causing the two to liquefy together. After the laser scans, it quickly cools and solidifies, and then a layer of nickel is remelted on the surface of the aluminum sheet.

[0031] The aluminum sheet can be easily tinned through the nickel layer on the surface of the aluminum sheet.

[0032] Example 2

[0033] A production process for a sintered nickel layer on an aluminum sheet comprises the following steps:

[0034] S1. Prepare nickel slurry: mix nano nickel powder (CAS registration number: 7440-02-0), resin and binder to obtain nickel slurry, wherein the nano nickel powder accounts for more than 50%;

[0035] S2, applying nickel paste: the nickel paste obtained in S1 is uniformly applied on the surface of the aluminum sheet by a screen printing process, and the thickness of the applied nickel paste is 0.2 mm, wherein the nickel paste can be applied locally or integrally;

[0036] S3, primary sintering: the aluminum sheet coated with the nickel paste is irradiated by a CO2 laser or a fiber laser with a continuous power of 200 W; the laser adopts a defocusing amount of +5 mm or a multi-mode light spot to enable the laser to heat the resin and the binder in the nickel paste, the galvanometer speed is set to 900 mm / s, the image linear filling interval is 0.15 mm, and the temperature is controlled at about 500℃, and the non-metallic components such as resin in the nickel paste are rapidly decomposed and volatilized, while the melting point of nickel is above 1453℃, and finally the nano-nickel powder is left to cover the aluminum surface layer;

[0037] S4, secondary sintering: the aluminum sheet surface layer with nano-nickel powder is irradiated again by a CO2 laser or a fiber laser with a continuous power of 300 W, in order to rapidly raise the heating temperature to above the melting point of nickel (1453℃), the laser adopts a defocusing amount of +5.5 mm to obtain a relatively high energy density, in addition, the melting point of aluminum is only 660℃, which is much lower than that of nickel, in order to avoid large deformation of the aluminum sheet caused by high-temperature heating, the galvanometer speed is set to 250 mm / s, and when the image linear filling interval is 0.15 mm, the temperature of the nano-nickel powder on the surface layer of the aluminum sheet rapidly rises above the melting point of nickel, and is transmitted from the upper nano-nickel powder to the aluminum sheet, so that the two are liquefied together, and after the laser scanning, they are rapidly cooled and solidified, and then a layer of nickel is remelted on the surface of the aluminum sheet.

[0038] The production process described in examples 1 and 2 is based on laser equipment as a carrier, has high flexibility and automation, and is very beneficial to integration into a fully automated production line; in addition, the laser sintering process has low pollution, low energy consumption, high efficiency, and saves a large amount of production cost and social resources; furthermore, compared with copper, the density of metal aluminum is lighter and the cost is lower; the aluminum sheet with a nickel layer can be directly tin-plated, which will promote the application of aluminum in the new energy industry and has important significance for reducing the cost of the industry.

[0039] The above embodiments only serve to illustrate the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application, and any equivalent changes or modifications made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

Claims

1. A production process for sintering nickel layer on aluminum sheet, characterized in that: The following steps are involved: S1. Prepare nickel slurry: mix nano nickel powder, resin and binder evenly to obtain nickel slurry; S2. Applying nickel paste: Apply the nickel paste obtained in S1 evenly on the surface of the aluminum sheet through a silk screen printing process; S3. Primary sintering: Use a laser to heat the aluminum sheet coated with nickel paste at a continuous power of 15W to 250W. The heating temperature is controlled at 250℃ to 550℃. The resin and binder in the nickel paste are decomposed and volatilized, leaving nano nickel powder covering the aluminum sheet. S4. Secondary sintering: Use a laser to heat the surface of the aluminum sheet with nano-nickel powder again at a continuous power of 200W to 500W. The heating temperature is greater than 1453℃. The temperature of the nano-nickel powder on the surface of the aluminum sheet rises above the melting point of nickel and is transferred from the nano-nickel powder on the upper layer to the aluminum sheet, causing the two to liquefy together. After the laser scans, it cools and solidifies, and a layer of nickel is re-melted on the surface of the aluminum sheet.

2. The production process of the aluminum sheet sintered nickel layer according to claim 1, characterized in that: The content of nano nickel powder in the nickel paste exceeds 50%.

3. The production process of aluminum sheet sintered nickel layer according to claim 1, characterized in that: The nickel paste has a coating thickness of 0.1 to 0.3 mm.

4. The production process of the aluminum sheet sintered nickel layer according to claim 1, characterized in that: The laser is a CO2 laser or a fiber laser.

5. The production process of aluminum sheet sintered nickel layer according to claim 1, characterized in that: In step S3, the defocusing amount of the laser is +2 to +8 mm, the galvanometer speed is 200 to 1500 mm / s, and the image straight line filling interval is 0.07 to 0.3 mm.

6. The production process of aluminum sheet sintered nickel layer according to claim 5, characterized in that: In step S3, the power of the laser is 200 W, the defocus is +5 mm, the galvanometer speed is 900 mm / s, and the image straight line filling interval is 0.15 mm.

7. The production process of the aluminum sheet sintered nickel layer according to claim 1, characterized in that: In step S4, the defocus of the laser is +1 to +7 mm, the galvanometer speed is 150 to 350 mm / s, and the image straight line filling interval is 0.06 to 0.2 mm.

8. The production process of the aluminum sheet sintered nickel layer according to claim 7, characterized in that: In step S4, the power of the laser is 300 W, the defocus amount is +5.5 mm, the galvanometer speed is 250 mm / s, and the image straight line filling interval is 0.15 mm.

9. The production process of aluminum sheet sintered nickel layer according to claim 1, characterized in that: In step S3, the heating temperature of the nickel slurry exceeds 1453°C.