Abstract
Provided is a process for producing a tinned copper wire. The process comprises subjecting a copper wire sequentially to activation treatment, a first hot tinning treatment, a first cooling, a second hot tinning treatment, and a second cooling to obtain a tinned copper wire. The first hot tinning treatment is carried out at a first temperature and the second hot tinning treatment is carried out at a second temperature. The first temperature is higher than the second temperature. The first temperature is at least 38° C. higher than the melting point of tin. The second temperature is at least 8° C. higher than the melting point of tin.
Claims
1. A process for producing a tinned copper wire, comprising: subjecting a copper wire sequentially to activation treatment, a first hot tinning treatment, a first cooling, a second hot tinning treatment, and a second cooling to obtain a tinned copper wire, wherein: the first hot tinning treatment is carried out at a first temperature; the second hot tinning treatment is carried out at a second temperature; the first temperature is higher than the second temperature; the first temperature is at least 38° C. higher than the melting point of tin; and the second temperature is at least 8° C. higher than the melting point of tin.
2. The process of claim 1 wherein the first hot tinning treatment is carried out at a temperature between 270° C. and 320° C., and wherein the second hot tinning treatment is carried out at a temperature between 240° C. and 245° C.
3. The process of claim 2 wherein the second hot tinning treatment is carried out with a molten tin liquid comprising a rare metal in an amount of less than or equal to 0.1 wt %, and preferably the rare metal is at least one of indium, bismuth, and nickel.
4. The process of claim 2 wherein the first hot tinning treatment is carried out with a molten tin liquid comprising copper in an amount of less than or equal to 0.7 wt %, and wherein the molten tin liquid for the second hot tinning treatment comprises copper in an amount of less than or equal to 2.0 wt %.
5. The process of claim 2 wherein the second cooling is carried out by a wind cooling method, preferably at a wind speed of 10-15 meters per second with a wind direction that is perpendicular to the copper wire.
6. The process of claim 2 wherein the copper wire is conveyed at a speed of 150-400 meters per minute during the process.
7. The process of claim 2 wherein the activation treatment comprises activating the copper wire with a flux.
8. The process of claim 2 wherein a cooling length of the copper wire in the first cooling is 1.0-1.5 meters.
9. The process claim 2 wherein the molten tin liquid for the first hot tinning treatment comprises phosphorus in an amount of 0.01-0.1 wt %.
10. The process of claim 1 wherein the second hot tinning treatment is carried out with a molten tin liquid comprising a rare metal in an amount of less than or equal to 0.1 wt %, and preferably the rare metal is at least one of indium, bismuth, and nickel.
11. The process of claim 10 wherein the first hot tinning treatment is carried out with a molten tin liquid comprising copper in an amount of less than or equal to 0.7 wt %, and wherein the molten tin liquid for the second hot tinning treatment comprises copper in an amount of less than or equal to 2.0 wt %.
12. The process of claim 10 wherein the second cooling is carried out by a wind cooling method, preferably at a wind speed of 10-15 meters per second with a wind direction that is perpendicular to the copper wire.
13. The process of claim 1 wherein the first hot tinning treatment is carried out with a molten tin liquid comprising copper in an amount of less than or equal to 0.7 wt %, and wherein the molten tin liquid for the second hot tinning treatment comprises copper in an amount of less than or equal to 2.0 wt %.
14. The process of claim 13 wherein the second cooling is carried out by a wind cooling method, preferably at a wind speed of 10-15 meters per second with a wind direction that is perpendicular to the copper wire.
15. The process of claim 1 wherein the second cooling is carried out by a wind cooling method, preferably at a wind speed of 10-15 meters per second with a wind direction that is perpendicular to the copper wire.
16. The process of claim 1 wherein the copper wire is conveyed at a speed of 150-400 meters per minute during the process.
17. The process of claim 16 wherein the copper wire is conveyed at a speed of 150-200 meters per minute when the copper wire has a diameter of greater than 0.8 millimeters (mm), or 300-400 meters per minute when the copper wire has a diameter of less than 0.1 mm, or 200-300 meters per minute when the copper wire has a diameter of 0.1-0.8 mm.
18. The process of claim 1 wherein the activation treatment comprises activating the copper wire with a flux.
19. The process of claim 1 wherein a cooling length of the copper wire in the first cooling is 1.0-1.5 meters.
20. The process claim 1 wherein the molten tin liquid for the first hot tinning treatment comprises phosphorus in an amount of 0.01-0.1 wt %.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] In order to more clearly describe the specific embodiments of the present application or the technical solutions in the prior art, a brief description of the drawings required in the specific embodiments or descriptions of the prior art is given below. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by one of ordinary skill in the art according to the drawings in the present application without creative work.
[0039] FIG. 1 is a process for producing a tinned copper wire in embodiment 1 of the present application.
[0040] Reference numbers are as follows:
[0041] 1—copper wire; 2—first hot tinning furnace; 3—second hot tinning furnace; 4—mold; 5—fans; 6—surface activation device; 7—zirconia ceramic guide wheel;
[0042] 2-1—molten tin liquid during the first hot tinning treatment; and
[0043] 3-1—molten tin liquid during the second hot tinning treatment.
DETAILED DESCRIPTION
[0044] It The present application is further described by referring to but not limit to the following embodiments. Any product that is the same as or similar to the present application obtained by anyone under the teaching of the present application or by combining with other features of the prior art falls within the protection scope of the present application.
[0045] Experimental steps or conditions not noted in the embodiments can be carried out according to the operation or the condition of the conventional experimental steps described in the art. The used reagents or instruments, for which the manufacturers are not noted, are all conventional reagent products which are commercially available.
Embodiment 1
[0046] Provided is a process for producing a tinned copper wire, as shown in FIG. 1, the steps of which are described as follows:
[0047] An annealed bare copper wire 1 having a diameter of 1.18 mm was selected, and conveyed at a speed of 180 m/min in a direction as indicated in FIG. 1 to start the process for tinning. Firstly, the copper wire was conveyed into a surface activation device 6 where activation treatment was carried out on the surface of the copper wire using ZnCl2 aqueous solution as a flux (purchased from Shenzhen Mingxinshun Technology Co., Ltd.). Then the copper wire was conveyed into a molten tin liquid 2-1 in a first hot tinning furnace 2 to receive a first hot tinning treatment. The copper wire was conveyed via a zirconia ceramic guide wheel 7, and there was no mold in the first hot tinning furnace. The molten tin liquid 2-1 had a temperature of 320° C. and comprised phosphorus in an amount of 0.1 wt %. Then the copper wire was conveyed out of the molten tin liquid in the first hot tinning furnace and exposed in natural air to undergo a first cooling by the natural air outside the furnace. During the first cooling a cooling length of the copper wire in the natural air is 1.5 m. Then the copper wire was conveyed into in a molten tin liquid 3-1 in a second hot tinning furnace 3 to receive a second hot tinning treatment. The molten tin liquid 3-1 had a temperature of 245° C. and comprised a rare metal in an amount of 0.08 wt % (the rare metal was composed of indium, bismuth, and nickel at a mass ratio of 1:1:1). In the second hot tinning furnace, the copper wire was conveyed via another zirconia ceramic guide wheel 7, and a mold 4 was provided at a position where the copper wire left the molten tin liquid. The mold was provided with a round through hole having a diameter of 1.2 mm. The copper wire was passed through the round through hole to leave the molten tin liquid in the second hot tinning furnace and enter a second cooling process. The second cooling was carried out by a wind cooling method. A number of fans 5 were provided and arrange to parallel to the conveying direction of the copper wire such that wind outlets of the fans are perpendicular to the copper wire and thus the wind direction was perpendicular to the copper wire. The wind speed was 15 m/s. The length of the copper wire blown by the wind was 1.2 m (length of the copper wire exposed to the second cooling). The most upstream fan in the conveying direction is disposed at a distance of 0.5 m (based on the length of the copper wire) from the mold. Finally, a tinned copper wire having a diameter of 1.2 mm was obtained, and was taken up for storage.
[0048] In the present embodiment, twelve zirconia ceramic guide wheels were provide in each of the first hot tinning furnace and the second hot tinning furnace, and twelve molds were provided in the second hot tinning furnace, and there are twelve wire taking-up devices, so that twelve production lines can run at the same time.
Embodiment 2
[0049] Provided is a process for producing a tinned copper wire, the steps of which are described as follows:
[0050] An annealed bare copper wire 1 having a diameter of 0.49 mm was selected, and conveyed at a speed of 260 m/min in a direction as indicated in FIG. 1 to start the process for tinning. Firstly, the copper wire was conveyed into a surface activation device where activation treatment was carried out on the surface of the copper wire using ZnCl2 aqueous solution as a flux. Then the copper wire was conveyed into a molten tin liquid in a first hot tinning furnace to receive a first hot tinning treatment. The copper wire was conveyed via a zirconia ceramic guide wheel, and there was no mold in the first hot tinning furnace. The molten tin liquid had a temperature of 280° C. and comprised phosphorus in an amount of 0.08 wt %. Then the copper wire was conveyed out of the molten tin liquid in the first hot tinning furnace and exposed in natural air to undergo a first cooling by the natural air outside the furnace. During the first cooling a cooling length of the copper wire in the natural air is 1.5 m. Then the copper wire was conveyed into in a molten tin liquid in a second hot tinning furnace to receive a second hot tinning treatment. The molten tin liquid had a temperature of 242° C. and comprised a rare metal in an amount of 0.08 wt % (the rare metal was composed of indium, bismuth, and nickel at a mass ratio of 1:1:2). In the second hot tinning furnace, the copper wire was conveyed via another zirconia ceramic guide wheel, and a mold was provided at a position where the copper wire left the molten tin liquid. The mold was provided with a round through hole having a diameter of 0.5 mm. The copper wire was passed through the round through hole to leave the molten tin liquid in the second hot tinning furnace and enter a second cooling process. The second cooling was carried out by a wind cooling method. A number of fans were provided and arrange to parallel to the conveying direction of the copper wire such that wind outlets of the fans are perpendicular to the copper wire and thus the wind direction was perpendicular to the copper wire. The wind speed was 15 m/s. The length of the copper wire blown by the wind was 1 m (length of the copper wire exposed to the second cooling). The most upstream fan in the conveying direction is disposed at a distance of 0.5 m (based on the length of the copper wire) from the mold. Finally, a tinned copper wire having a diameter of 0.5 mm was obtained, and was taken up for storage.
[0051] In the present embodiment, sixteen production lines can run at the same time.
Embodiment 3
[0052] Provided is a process for producing a tinned copper wire, the steps of which are described as follows:
[0053] An annealed bare copper wire 1 having a diameter of 0.074 mm was selected, and conveyed at a speed of 350 m/min in a direction as indicated in FIG. 1 to start the process for tinning. Firstly, the copper wire was conveyed into a surface activation device where activation treatment was carried out on the surface of the copper wire using ZnCl2 aqueous solution as a flux. Then the copper wire was conveyed into a molten tin liquid in a first hot tinning furnace to receive a first hot tinning treatment. The copper wire was conveyed via a zirconia ceramic guide wheel, and there was no mold in the first hot tinning furnace. The molten tin liquid had a temperature of 270° C. and comprised phosphorus in an amount of 0.1 wt %. Then the copper wire was conveyed out of the molten tin liquid in the first hot tinning furnace and exposed in natural air to undergo a first cooling by the natural air outside the furnace. During the first cooling a cooling length of the copper wire in the natural air is 1.2 m. Then the copper wire was conveyed into in a molten tin liquid in a second hot tinning furnace to receive a second hot tinning treatment. The molten tin liquid had a temperature of 240° C. and comprised a rare metal in an amount of 0.05 wt % (the rare metal was composed of indium, bismuth, and nickel at a mass ratio of 1:1:2). In the second hot tinning furnace, the copper wire was conveyed via another zirconia ceramic guide wheel, and a mold was provided at a position where the copper wire left the molten tin liquid. The mold was provided with a round through hole having a diameter of 0.08 mm. The copper wire was passed through the round through hole to leave the molten tin liquid in the second hot tinning furnace and enter a second cooling process. The second cooling was carried out by a wind cooling method. A number of fans were provided and arrange to parallel to the conveying direction of the copper wire such that wind outlets of the fans are perpendicular to the copper wire and thus the wind direction was perpendicular to the copper wire. The wind speed was 15 m/s. The length of the copper wire blown by the wind was 0.85 m (length of the copper wire exposed to the second cooling). The most upstream fan in the conveying direction is disposed at a distance of 0.5 m (based on the length of the copper wire) from the mold. Finally, a tinned copper wire having a diameter of 0.08 mm was obtained, and was taken up for storage.
[0054] In the present embodiment, twenty-four production lines can run at the same time.
Embodiment 4
[0055] Provided is a process for producing a tinned copper wire, the steps of which are described as follows:
[0056] An annealed bare copper wire 1 having a diameter of 1.18 mm was selected, and conveyed at a speed of 180 m/min in a direction as indicated in FIG. 1 to start the process for tinning. Firstly, the copper wire was conveyed into a surface activation device 6 where activation treatment was carried out on the surface of the copper wire using ZnCl2 aqueous solution as a flux. Then the copper wire was conveyed into a molten tin liquid 2-1 in a first hot tinning furnace 2 to receive a first hot tinning treatment. The copper wire was conveyed via a zirconia ceramic guide wheel 7, and there was no mold in the first hot tinning furnace. The molten tin liquid 2-1 had a temperature of 300° C. and comprised phosphorus in an amount of 0.1 wt %. Then the copper wire was conveyed out of the molten tin liquid in the first hot tinning furnace and exposed in natural air to undergo a first cooling by the natural air outside the furnace. During the first cooling a cooling length of the copper wire in the natural air is 1.5 m. Then the copper wire was conveyed into in a molten tin liquid 3-1 in a second hot tinning furnace 3 to receive a second hot tinning treatment. The molten tin liquid 3-1 had a temperature of 270° C. and comprised a rare metal in an amount of 0.08 wt % (the rare metal was composed of indium, bismuth, and nickel at a mass ratio of 1:1:1). In the second hot tinning furnace, the copper wire was conveyed via another zirconia ceramic guide wheel 7, and a mold 4 was provided at a position where the copper wire left the molten tin liquid. The mold was provided with a round through hole having a diameter of 1.2 mm. The copper wire was passed through the round through hole to leave the molten tin liquid in the second hot tinning furnace and enter a second cooling process. The second cooling was carried out by a wind cooling method. A number of fans 5 were provided and arrange to parallel to the conveying direction of the copper wire such that wind outlets of the fans are perpendicular to the copper wire and thus the wind direction was perpendicular to the copper wire. The wind speed was 15 m/s. The length of the copper wire blown by the wind was 1.2 m (length of the copper wire exposed to the second cooling). The most upstream fan in the conveying direction is disposed at a distance of 0.5 m (based on the length of the copper wire) from the mold. Finally, a tinned copper wire having a diameter of 1.2 mm was obtained, and was taken up for storage.
[0057] In the present embodiment, twelve zirconia ceramic guide wheels were provide in each of the first hot tinning furnace and the second hot tinning furnace, and twelve molds were provided in the second hot tinning furnace, and there are twelve wire taking-up devices, so that twelve production lines can run at the same time.
Embodiment 5
[0058] Provided is a process for producing a tinned copper wire, the steps of which are described as follows:
[0059] An annealed bare copper wire 1 having a diameter of 0.49 mm was selected, and conveyed at a speed of 260 m/min in a direction as indicated in FIG. 1 to start the process for tinning. Firstly, the copper wire was conveyed into a surface activation device where activation treatment was carried out on the surface of the copper wire using ZnCl2 aqueous solution as a flux. Then the copper wire was conveyed into a molten tin liquid in a first hot tinning furnace to receive a first hot tinning treatment. The copper wire was conveyed via a zirconia ceramic guide wheel, and there was no mold in the first hot tinning furnace. The molten tin liquid had a temperature of 280° C. and comprised phosphorus in an amount of 0.08 wt %. Then the copper wire was conveyed out of the molten tin liquid in the first hot tinning furnace and exposed in natural air to undergo a first cooling by the natural air outside the furnace. During the first cooling a cooling length of the copper wire in the natural air is 1.5 m. Then the copper wire was conveyed into in a molten tin liquid in a second hot tinning furnace to receive a second hot tinning treatment. The molten tin liquid had a temperature of 242° C. and comprised a rare metal in an amount of 0.08 wt % (the rare metal was composed of indium and bismuth at a mass ratio of 1:1). In the second hot tinning furnace, the copper wire was conveyed via another zirconia ceramic guide wheel, and a mold was provided at a position where the copper wire left the molten tin liquid. The mold was provided with a round through hole having a diameter of 0.5 mm. The copper wire was passed through the round through hole to leave the molten tin liquid in the second hot tinning furnace and enter a second cooling process. The second cooling was carried out by a wind cooling method. A number of fans were provided and arrange to parallel to the conveying direction of the copper wire such that wind outlets of the fans are perpendicular to the copper wire and thus the wind direction was perpendicular to the copper wire. The wind speed was 15 m/s. The length of the copper wire blown by the wind was 1 m (length of the copper wire exposed to the second cooling). The most upstream fan in the conveying direction is disposed at a distance of 0.5 m (based on the length of the copper wire) from the mold. Finally, a tinned copper wire having a diameter of 0.5 mm was obtained, and was taken up for storage.
[0060] In the present embodiment, sixteen production lines can run at the same time.
Embodiment 6
[0061] Provided is a process for producing a tinned copper wire, the steps of which are described as follows:
[0062] An annealed bare copper wire 1 having a diameter of 0.49 mm was selected, and conveyed at a speed of 260 m/min in a direction as indicated in FIG. 1 to start the process for tinning. Firstly, the copper wire was conveyed into a surface activation device where activation treatment was carried out on the surface of the copper wire using ZnCl2 aqueous solution as a flux. Then the copper wire was conveyed into a molten tin liquid in a first hot tinning furnace to receive a first hot tinning treatment. The copper wire was conveyed via a zirconia ceramic guide wheel, and there was no mold in the first hot tinning furnace. The molten tin liquid had a temperature of 280° C. and comprised phosphorus in an amount of 0.08 wt %. Then the copper wire was conveyed out of the molten tin liquid in the first hot tinning furnace and exposed in natural air to undergo a first cooling by the natural air outside the furnace. During the first cooling a cooling length of the copper wire in the natural air is 1.5 m. Then the copper wire was conveyed into in a molten tin liquid in a second hot tinning furnace to receive a second hot tinning treatment. The molten tin liquid had a temperature of 242° C. and comprised a rare metal in an amount of 0.05 wt % (the rare metal was bismuth). In the second hot tinning furnace, the copper wire was conveyed via another zirconia ceramic guide wheel, and a mold was provided at a position where the copper wire left the molten tin liquid. The mold was provided with a round through hole having a diameter of 0.5 mm. The copper wire was passed through the round through hole to leave the molten tin liquid in the second hot tinning furnace and enter a second cooling process. The second cooling was carried out by a wind cooling method. A number of fans were provided and arrange to parallel to the conveying direction of the copper wire such that wind outlets of the fans are perpendicular to the copper wire and thus the wind direction was perpendicular to the copper wire. The wind speed was 12 m/s. The length of the copper wire blown by the wind was 1 m (length of the copper wire exposed to the second cooling). The most upstream fan in the conveying direction is disposed at a distance of 0.5 m (based on the length of the copper wire) from the mold. Finally, a tinned copper wire having a diameter of 0.5 mm was obtained, and was taken up for storage.
[0063] In the present embodiment, sixteen production lines can run at the same time.
Comparative Example 1
[0064] Provided is a process for producing a tinned copper wire, the steps of which are described as follows:
[0065] An annealed bare copper wire 1 having a diameter of 0.49 mm was selected, and conveyed at a speed of 260 m/min in a direction as indicated in FIG. 1 to start the process for tinning. Firstly, the copper wire was conveyed into a surface activation device where activation treatment was carried out on the surface of the copper wire using ZnCl2 aqueous solution as a flux. Then the copper wire was conveyed into a molten tin liquid in a first hot tinning furnace to receive a first hot tinning treatment. The copper wire was conveyed via a zirconia ceramic guide wheel, and there was no mold in the first hot tinning furnace. The molten tin liquid had a temperature of 280° C. and comprised phosphorus in an amount of 0.08 wt %. Then the copper wire was conveyed out of the molten tin liquid in the first hot tinning furnace and exposed in natural air to undergo a first cooling by the natural air outside the furnace. During the first cooling a cooling length of the copper wire in the natural air is 1.5 m. Then the copper wire was conveyed into in a molten tin liquid in a second hot tinning furnace to receive a second hot tinning treatment. The molten tin liquid had a temperature of 280° C. and comprised a rare metal in an amount of 0.08 wt % (the rare metal was composed of indium, bismuth, and nickel). In the second hot tinning furnace, the copper wire was conveyed via another zirconia ceramic guide wheel, and a mold was provided at a position where the copper wire left the molten tin liquid. The mold was provided with a round through hole having a diameter of 0.5 mm. The copper wire was passed through the round through hole to leave the molten tin liquid in the second hot tinning furnace and enter a second cooling process. The second cooling was carried out by a wind cooling method. A number of fans were provided and arrange to parallel to the conveying direction of the copper wire such that wind outlets of the fans are perpendicular to the copper wire and thus the wind direction was perpendicular to the copper wire. The wind speed was 15 m/s. The length of the copper wire blown by the wind was 1 m (length of the copper wire exposed to the second cooling). The most upstream fan in the conveying direction is disposed at a distance of 0.5 m (based on the length of the copper wire) from the mold. Finally, a tinned copper wire having a diameter of 0.5 mm was obtained, and was taken up for storage
Test Example
[0066] This test example provides performance test methods and results of the tinned copper wires prepared in embodiments 1-6 and comparative example 1.
[0067] The diameter, surface quality, heat resistance, salt spray resistance and the thickness of tin layer on tinned copper wire are tested according to GBT4910-2009; and the test results are shown in the following table.
TABLE-US-00001 Deviation Thickness Diameter of Quality of the surface of tin Salt spray No. (mm) diameter of the tin layer Heat resistance layer (μm) resistance Embodiment 1.198 ±0.002 The surface is smooth The surface of tin layer is 9 The surface is 1 and continuous, free of yellow color, smooth, free of without defects. uncoated holes, molten tin, black or yellow and tin coating shedding. phenomenon. Embodiment 0.501 ±0.002 The surface is smooth The surface of tin layer is 5.5 The surface is free 2 and continuous, free of yellow color, of black or yellow without defects. uncoated holes, molten tin, phenomenon. and tin coating shedding. Embodiment 0.081 ±0.002 The surface is smooth The surface of tin layer is 3.5 The surface is free 3 and continuous, free of yellow color, of black or yellow without defects. uncoated holes, molten tin, phenomenon. and tin coating shedding. Embodiment 1.191 ±0.003 The surface is not The surface of tin layer is 5.5 The surface is free 4 smooth enough. free of yellow color, of black or yellow uncoated holes, molten tin, phenomenon. and tin coating shedding. Embodiment 0.500 ±0.001 The surface is smooth The surface of tin layer is 5.0 The surface is free 5 and continuous, slightly dark, free of of black or yellow without defects. uncoated holes, molten tin, phenomenon. and tin coating shedding. Embodiment 0.500 ±0.001 The surface is smooth The surface of tin layer is 5.0 The surface is 6 and continuous, slightly dark, free of slightly black. without defects. uncoated holes, molten tin, and tin coating shedding. Comparative 0.498 ±0.003 The surface is not The surface of tin layer is 4 The surface is example 1 smooth enough. free of yellow color, but has slightly black. a small amount of uncoated holes and tin coating shedding.
[0068] The tinned copper wires produced by the process of the present application have better heat resistance and salt spray resistance, the tin layer on the copper wire has a uniform thickness and continuous smooth surface, and the deviation of diameter is small. Meanwhile, the speed of conveying the copper wire is fast during this production process, and multiple production lines can run at the same time, so the production efficiency is much higher than other existing production methods of the same specification. In addition, the molten tin liquid during the hot tinning process has a long service life, the tin consumption is greatly reduced, and the utilization rate of tin is improved.
[0069] In addition, the tin layer on the tinned copper wire obtained by the production process can reach a thickness up to 9 micrometers (μm), which is surprising because the thickness of the tin layer obtained by the existing hot tinning processes cannot be greater than 6 μm.
[0070] Apparently, the aforementioned embodiments are merely examples illustrated for clearly describing the present application, rather than limiting the implementation ways thereof. For those skilled in the art, various changes and modifications in other different forms can be made on the basis of the aforementioned description. The implementation ways are not described exhaustively. Any obvious changes or modifications derived from the aforementioned description are intended to be embraced within the protection scope of the present application.
