A method and apparatus for galvanic cathodic electrical contact

Abstract

The present invention relates to a method and apparatus for using an electroplating cathode, and more particularly to a method and apparatus for electroplating cathode electrical contact during a horizontal double-side electroplating process for a crystalline silicon solar cell. The method and apparatus for electroplating cathode electrical contact of the present invention can effectively prevent the possible copper plating resolution problem during the horizontal double-side electroplating process for a crystalline silicon solar cell.

Description

Technical Field

[0001] This invention relates to a method and apparatus for using an electroplated cathode, and particularly to a method and apparatus for electroplating cathode electrical contacts during horizontal double-sided electroplating of crystalline silicon solar cells. The method and apparatus for electroplating cathode electrical contacts of this invention can effectively prevent electroplated copper stripping problems that may occur during horizontal double-sided electroplating of crystalline silicon solar cells. Background Technology

[0002] Chinese Patent Application No. 201510992736.6 discloses a method and apparatus for simultaneously performing horizontal electroplating on the upper and lower surfaces of a solar cell, specifically a method and apparatus for performing horizontal double-sided electroplating on a crystalline silicon solar cell. The method and apparatus have multiple independent electroplating tanks. Conductive transfer rollers are installed on both sides of each electroplating tank, serving as cathode conductive contacts and transferring the crystalline silicon solar cell during the electroplating process. The conductive transfer rollers on both sides of the electroplating tank are connected to the negative terminal of an electroplating DC power supply, and the positive terminal of the electroplating DC power supply is connected to the lower anode in the electroplating tank and the upper anode above the solar cell. Simultaneously, horizontal electroplating is performed on both the upper and lower surfaces of the crystalline silicon solar cell while it is being horizontally transferred.

[0003] However, when performing horizontal electroplating on the upper and lower surfaces of a solar cell while implementing the patent, copper desorption occurs on both sides of the upper surface of the crystalline silicon solar cell in the horizontal direction of movement.

[0004] The purpose of this invention is to overcome these defects. Summary of the Invention

[0005] To address the shortcomings of the prior art, this invention discloses a method and apparatus for electroplating cathode electrical contacts.

[0006] This invention discovers that if the lower surface edge area on both sides of the horizontal movement direction of the crystalline silicon solar cell is prevented from making conductive contact with the conductive transmission roller, the risk of copper desorption on the upper surface of the crystalline silicon solar cell can be avoided.

[0007] Therefore, the present invention discloses a conductive transmission roller structure, characterized in that the two lower surfaces of the crystalline silicon solar cell in the horizontal moving direction do not make conductive contact with the conductive transmission roller.

[0008] The advantage of the conductive transmission roller structure disclosed in this invention is that, since the lower surfaces on both sides of the crystalline silicon solar cell in the horizontal movement direction do not make conductive contact with the conductive transmission roller, the risk of copper degradation on the upper surfaces on both sides of the crystalline silicon solar cell in the horizontal movement direction can be avoided. Attached Figure Description

[0009] Figure 1 A schematic diagram of a method and apparatus for electroplating cathode electrical contacts according to the present invention.

[0010] Figure 2. Schematic diagram of one embodiment of the method and apparatus for electroplating cathode electrical contact according to the present invention.

[0011] Figure 3 A schematic diagram of a second embodiment of the method and apparatus for electroplating cathode electrical contacts according to the present invention.

[0012] Figure 4 A schematic diagram of a third embodiment of the method and apparatus for electroplating cathode electrical contacts according to the present invention. Detailed Implementation

[0013] In the following description, detailed embodiments of the invention are set forth for illustrative purposes to aid in a comprehensive understanding of the invention. Clearly, these descriptions are not intended to limit the invention. Various other corresponding combinations, modifications, or alterations can be made by those skilled in the art based on the invention without departing from its spirit and essence. These corresponding combinations, modifications, and alterations all fall within the scope of protection of the appended claims.

[0014] One feature of the method and apparatus for electroplating cathode electrical contacts according to the present invention is that, after the conductive transfer roller 10 contacts the lower surface of the crystalline silicon solar cell 20, the upper and lower surfaces of the crystalline silicon solar cell 20 become the cathodes of the electroplating process; furthermore, the conductive transfer roller 10 only makes conductive contact with the middle majority area of ​​the lower surface of the crystalline silicon solar cell 20 along the horizontal movement direction, while the two small areas on both sides of the lower surface of the crystalline silicon solar cell 20 do not make conductive contact with the conductive transfer roller, that is, the lower surface of the crystalline silicon solar cell 20 only forms localized conductive contact with the conductive roller 10 in the middle region. The conductive transfer roller in the method and apparatus for electroplating cathode electrical contacts of the present invention simultaneously plays a dual role in the horizontal transmission of the crystalline silicon solar cell and the electrical conduction of the horizontally double-sided electroplated crystalline silicon solar cell.

[0015] Appendix Figure 1A schematic diagram of a method and apparatus for electroplating a cathode electrical contact according to the present invention is shown. The method and apparatus for electroplating a cathode electrical contact according to the present invention comprises multiple electroplating baths 130; each electroplating bath 130 contains at least one insulating transfer roller 80; each electroplating bath 130 has at least one conductive transfer roller 10 on each of its two sides, the lower surface of the crystalline silicon solar cell 20 is in contact with the conductive transfer roller 10, and the conductive transfer roller 10 serves both as a transfer roller for transporting the crystalline silicon solar cell 20 and as a conductive contact for the cathode in the electroplating process of the present invention; a lower anode 120 is located within the electroplating bath 130; an upper anode 110 is located above the electroplating bath 130; the method and apparatus for electroplating a cathode electrical contact according to the present invention uses multiple DC electroplating power supplies for electroplating, such as DC electroplating power supplies 140, 141, 150, 151, 160, and 161, etc. The crystalline silicon solar cell 20 is horizontally transported from left to right by a conductive transport roller 10 and an insulating transport roller 80. During the transport process, the lower surface of the crystalline silicon solar cell 20 contacts the conductive transport roller 10 and the electroplating solution in the electroplating bath 130, while the electroplating solution 100 on the upper surface of the crystalline silicon solar cell 20 contacts the upper anode 110. Under the action of the DC electroplating power supplies 140, 141, 150, 151, 160, and 161 and the conductivity of the conductive transport roller 10, the upper and lower surfaces of the crystalline silicon solar cell 20 form the cathode surface of the electroplating process. Therefore, the upper and lower surfaces of the crystalline silicon solar cell 20 are electroplated simultaneously during the horizontal transport process.

[0016] Referring to Figure 2, a method and apparatus for electroplating cathode electrical contacts according to the present invention can be further described. Figure 2A This is a cross-sectional view of the crystalline silicon solar cell 20 in the direction of horizontal movement. Figure 2B yes Figure 2A A cross-sectional view to the left of the dashed line 60. The lower surface of the crystalline silicon solar cell 20 contacts the conductive transmission roller 10. If Figure 2B The conductive transmission roller 10 rotates clockwise, and the crystalline silicon solar cell 20 is transported from left to right by the conductive transmission roller 10. The conductive transmission roller 10 contacts the lower surface of the crystalline silicon solar cell 20, and conducts the potential of the electroplating DC power supply to the lower surface of the crystalline silicon solar cell 20, so that the lower and upper surfaces of the crystalline silicon solar cell 20 simultaneously become the cathode surfaces of the electroplating process.

[0017] The conductive transmission roller 10 can be made of metal, or it can be formed by coating a conductive film on the outer surface of an insulating roller. Furthermore, it can also be formed by wrapping a conductive film around an insulating roller.

[0018] Figure 2 illustrates an important feature of the conductive transmission roller 10 of the present invention: non-conductive regions exist between the first boundary 51 and the second boundary 52, and between the third boundary 53 and the fourth boundary 54. The first boundary 51 and the second boundary 52 define the boundaries of the non-conductive regions on one side of the conductive transmission roller 10, while the third boundary 53 and the fourth boundary 54 define the boundaries of the non-conductive regions on the other side. The first edge 31 and the second edge 32 are the two edges of the crystalline silicon solar cell 20 along the horizontal movement direction. The regions between the first edge 31 and the second boundary 52, and between the second edge 32 and the third boundary 53, in the horizontal movement direction of the crystalline silicon solar cell 20, have no physical contact with the conductive transmission roller 10, i.e., they do not conduct electricity. In other words, a non-conductive region is formed in the conductive transmission roller 10 by the region between the first boundary 51 and the second boundary 52, and the region between the third boundary 53 and the fourth boundary 54. The area formed by the region between the first edge 31 and the second boundary 52 and the region between the second edge 32 and the third boundary 53 in the horizontal movement direction of the crystalline silicon solar cell 20, along with the area formed by the side length of the crystalline silicon solar cell 20, does not have physical contact with the conductive transmission roller 10 because the diameter of the conductive transmission roller 10 in the non-conductive regions between the first boundary 51 and the second boundary 52, and in the non-conductive regions between the third boundary 53 and the fourth boundary 54, is smaller than the diameter of other parts. Therefore, there is no physical contact between the region between the first edge 31 and the second boundary 52 and the region between the second edge 32 and the third boundary 53 in the horizontal movement direction of the crystalline silicon solar cell 20 and the area formed by the side length of the crystalline silicon solar cell 20. The first edge 31 of the crystalline silicon solar cell 20 is located within the non-conductive regions of the first boundary 51 and the second boundary 52, while the second edge 32 of the crystalline silicon solar cell 20 is located within the non-conductive regions of the third boundary 53 and the fourth boundary 54. The purpose is to prevent the conductive transmission roller 10 from making physical contact with the two lower surfaces of the lower surface of the crystalline silicon solar cell 20 along the horizontal movement direction, or in other words, to prevent the conductive transmission roller 10 from conducting electricity with the two lower surfaces of the lower surface of the crystalline silicon solar cell 20 along the horizontal movement direction.

[0019] The width between the first boundary 51 and the second boundary 52, and between the third boundary 53 and the fourth boundary 54 of the non-conductive region described in this invention is between 1 mm and 100 mm, and the optimized width between the first boundary 51 and the second boundary 52, and between the third boundary 53 and the fourth boundary 54 of the non-conductive region is between 1 mm and 40 mm. The widths between the first boundary 51 and the second boundary 52, and between the third boundary 53 and the fourth boundary 54 of the non-conductive region can be the same or different. Furthermore, the area formed by the region between the first edge 31 and the second boundary 52 and the region between the second edge 32 and the third boundary 53 on the lower surface of the two sides of the crystalline silicon solar cell 20 in the horizontal moving direction, and the side length of the crystalline silicon solar cell 20, can be offset from the center point of the non-conductive region between the first boundary 51 and the second boundary 52, and between the third boundary 53 and the fourth boundary 54.

[0020] Figure 3 This is another embodiment of the present invention. The figure is a cross-sectional view of the crystalline silicon solar cell 20 on the conductive transfer roller 10, viewed from the horizontal movement direction of the crystalline silicon solar cell 20. Similarly, the conductive transfer roller 10 contacts the lower surface of the crystalline silicon solar cell 20, conducting the potential of the electroplating DC power supply to the lower surface of the crystalline silicon solar cell 20, making both the lower and upper surfaces of the crystalline silicon solar cell 20 the cathode surfaces of the electroplating process. One characteristic is that the diameters at both ends of the conductive transfer roller 10 are smaller than the diameter of the middle conductive transfer roller 10. An insulating material 15, such as plastic, rubber, or ceramic, is then fitted over the smaller diameter end of the conductive transfer roller 10, thereby forming a non-conductive region in the area between the first boundary 51 and the second boundary 52, and the third boundary 53 and the fourth boundary 54 of the conductive transfer roller 10. This design also achieves the same effect of preventing conductive contact between the conductive transmission roller 10 and the areas between the first edge 31 and the second boundary 52, and between the second edge 32 and the third boundary 53, on both sides of the lower surface of the crystalline silicon solar cell 20 in the horizontal movement direction during horizontal double-sided electroplating. In other applications of the present invention, the conductive transmission roller 10 is not fitted with any insulating material 15 at both ends, which also achieves the purpose of preventing conductive contact between the conductive transmission roller 10 and the lower surface of the crystalline silicon solar cell 20 on both sides in the horizontal movement direction.

[0021] like Figure 3As shown, the area between the first edge 31 and the second boundary 52 and the area between the second edge 32 and the third boundary 53 on the lower surface of the two sides of the crystalline silicon solar cell 20 in the horizontal moving direction, which is in contact with the area formed by the side length of the crystalline silicon solar cell 20, is the insulating part of the conductive transmission roller 10. In other words, it is the non-conductive area formed by the area between the first boundary 51 and the second boundary 52, as well as the area between the third boundary 53 and the fourth boundary 54 in the conductive transmission roller 10.

[0022] In this embodiment, the width between the first boundary 51 and the second boundary 52, and between the third boundary 53 and the fourth boundary 54 of the non-conductive region, is between 1 mm and 100 mm. The optimized width between the first boundary 51 and the second boundary 52, and between the third boundary 53 and the fourth boundary 54 of the non-conductive region, is between 1 mm and 40 mm. The widths of the first boundary 51 and the second boundary 52, and the third boundary 53 and the fourth boundary 54 of the non-conductive region can be the same or different. Of course, the area formed by the region between the first edge 31 and the second boundary 52 and the region between the second edge 32 and the third boundary 53 on the lower surface of the two sides of the crystalline silicon solar cell 20 in the horizontal movement direction, and the side length of the crystalline silicon solar cell 20, can deviate from the center point of the first boundary 51 and the second boundary 52, and the third boundary 53 and the fourth boundary 54 of the non-conductive region.

[0023] Figure 4 This is also a cross-sectional view of the crystalline silicon solar cell 20 on the conductive transfer roller 10, viewed from the horizontal movement direction. Similarly, the conductive transfer roller 10 contacts the lower surface of the crystalline silicon solar cell 20, conducting the potential of the electroplating DC power supply to the lower surface of the crystalline silicon solar cell 20, making both the lower and upper surfaces of the crystalline silicon solar cell 20 the cathode surfaces of the electroplating process. One characteristic is that an insulating film 16 is coated at both ends of the conductive transfer roller 10, thereby forming a non-conductive region in the area between the first boundary 51 and the second boundary 52, and between the third boundary 53 and the fourth boundary 54 of the conductive transfer roller 10. This design also avoids conductive contact between the area between the first edge 31 and the second boundary 52 and the area between the second edge 32 and the third boundary 53 on both sides of the lower surface of the crystalline silicon solar cell 20 in the horizontal movement direction and the area formed by the side length of the crystalline silicon solar cell 20.

[0024] In fact, in most applications, Figure 4 The insulating film 16 in the conductive transmission roller 10 should be very thin, for example, a few micrometers thick, so that it is basically unnecessary to cut grooves at both ends of the conductive transmission roller 10. The insulating film 16 in... Figure 4 The thickness is only used to clearly illustrate this embodiment.

[0025] Of course, in some applications, an insulating roller 40 can be placed on the silicon wafer. The weight of the insulating roller ensures that the crystalline silicon solar cell 20 can have good physical and conductive contact with the conductive transmission roller 10.

[0026] like Figure 4 As shown, the area between the first edge 31 and the second boundary 52 and the area between the second edge 32 and the third boundary 53 on the lower surface of the two sides of the crystalline silicon solar cell 20 in the horizontal moving direction, which is in contact with the area formed by the side length of the crystalline silicon solar cell 20, is the insulating part of the conductive transmission roller 10. In other words, it is the non-conductive area formed by the area between the first boundary 51 and the second boundary 52, and the third boundary 53 and the fourth boundary 54 in the conductive transmission roller 10.

[0027] Similarly, in this embodiment, the widths of the first and second boundaries 51 and the third and fourth boundaries 54 of the non-conductive region are between 1 mm and 100 mm, and the optimized widths between the first and second boundaries 51 and the third and fourth boundaries 53 and 54 of the non-conductive region are between 1 mm and 40 mm. The widths of the first and second boundaries 52 and the third and fourth boundaries 53 and 54 of the non-conductive region can be the same or different. Of course, the area formed by the region between the first edge 31 and the second boundary 52 and the region between the second edge 32 and the third boundary 53 on the lower surface of the two sides of the crystalline silicon solar cell 20 in the horizontal moving direction, and the side length of the crystalline silicon solar cell 20, can be deviated from the center point of the first and second boundaries 51 and the third and fourth boundaries 54 of the non-conductive region.

[0028] In addition to the technical features disclosed above, the device for electroplating cathode electrical contacts of the present invention includes, in addition to having, the areas formed by the regions between the first edge 31 and the second boundary 52 and the second edge 32 and the third boundary 53 on the lower surfaces of the two sides of the crystalline silicon solar cell 20 in the horizontal moving direction, and the areas formed by the side length of the crystalline silicon solar cell 20, respectively, located in the non-conductive regions between the first boundary 51 and the second boundary 52 and between the third boundary 53 and the fourth boundary 54 of the conductive transmission roller 10, the device further includes at least the following technical features: •The entire horizontal double-sided electroplating process includes at least four or more electroplating baths 130; • At least one conductive roller 90 is provided on each side of the electroplating bath 130 for cathode conductive transmission in the electroplating process. • The electroplating bath 130 contains an insulated transfer roller 80 and a lower anode 110; • An upper anode 70 is located above the electroplating bath 130; • The crystalline silicon solar cell 20 is horizontally transported by a conductive transport roller 10 and an insulating roller 80; • There should be at least one independent DC electroplating power supply.

[0029] The apparatus for electroplating cathode electrical contacts according to the present invention also includes other features. For example, before performing horizontal double-sided electroplating on the crystalline silicon solar cell 20, there are at least pretreatment steps on the electroplating surface of the crystalline silicon solar cell to make the crystalline silicon solar cell more uniformly electroplated and faster during the entire horizontal double-sided electroplating process; after performing horizontal double-sided electroplating on the crystalline silicon solar cell 20, there are at least cleaning and drying steps to clean and dry the surface of the crystalline silicon solar cell.

[0030] Other features of the electroplating cathode electrical contact device of the present invention include that the upper anode and the lower anode of the present invention can be soluble anodes or insoluble anodes.

Claims

1. A method for electroplating cathode electrical contacts, characterized in that, In the method described, the conductive transmission roller (10) serves as both a transmission roller for horizontally transmitting the crystalline silicon solar cell (20) and a conductive contact with the middle region of the lower surface of the crystalline silicon solar cell (20) along the horizontal moving direction, making the middle region a conductive contact region for the cathode in the electroplating process. The conductive transmission roller (10) is provided with two non-conductive regions along its axial direction that do not make conductive contact with the transistor solar cell (20), forming one non-conductive region by the first boundary (51) and the second boundary (52) and another non-conductive region by the third boundary (53) and the fourth boundary (54). The regions between the first edge (31) and the second boundary (52) on both sides of the lower surface of the crystalline silicon solar cell (20) in the horizontal moving direction, and the regions between the second edge (32) and the third boundary (53), correspond to the non-conductive regions, thus not making conductive contact with the conductive transmission roller (10), so that the lower surface of the crystalline silicon solar cell (20) only forms a local area conductive contact with the conductive transmission roller (10) in the middle region.

2. The method for electroplating cathode electrical contact according to claim 1, characterized in that, The regions between the first edge (31) and the second boundary (52) on the lower surface of the two sides of the crystalline silicon solar cell (20) in the horizontal moving direction, and the regions between the second edge (32) and the third boundary (53), do not form conductive contact with the conductive transmission roller (10) in the following ways: the above regions do not have physical contact with the conductive transmission roller (10); or, an insulating layer is provided at the contact position between the conductive transmission roller (10) and the above regions to form a non-conductive contact.

3. A method for electroplating cathode electrical contact according to claim 1 or 2, characterized in that, The width of the non-conductive region of the conductive transmission roller (10) between the first boundary (51) and the second boundary (52) and between the third boundary (53) and the fourth boundary (54) along the axial direction of the conductive transmission roller (10) is 1 to 40 mm.

4. A method for electroplating cathode electrical contact according to claim 1 or 2, characterized in that, An insulating roller (40) is located above the conductive transmission roller (10).

5. A method for electroplating cathode electrical contact according to claim 1 or 2, characterized in that, The conductive transmission roller (10) is made of metal, or is a conductive transmission roller (10) formed by coating an insulating roller with a conductive film; or is a conductive transmission roller (10) formed by wrapping an insulating roller with a conductive film.

6. An apparatus for electroplating cathode electrical contacts, characterized in that, The conductive transmission roller (10) forms a conductive contact with the middle area of ​​the lower surface of the crystalline silicon solar cell (20) along the horizontal moving direction, making the middle area a conductive contact area for the electroplated cathode; and the area between the first edge (31) and the second boundary (52) on both sides of the lower surface of the crystalline silicon solar cell (20) in the horizontal moving direction, and the area between the second edge (32) and the third boundary (53), correspond to the non-conductive area between the first boundary (51) and the second boundary (52) and the third boundary (53) and the fourth boundary (54) of the conductive roller (10), and does not conduct electricity with the conductive transmission roller (10).

7. The apparatus for electroplating cathode electrical contacts according to claim 6, characterized in that, The method to prevent the conductive transmission roller (10) from conducting electricity between the area between the first edge (31) and the second boundary (52) of the lower surface on both sides of the crystalline silicon solar cell (20) in the horizontal moving direction, and the area between the second edge (32) and the third boundary (53) of the lower surface on both sides of the crystalline silicon solar cell (20) in the horizontal moving direction, is to ensure that the area between the first edge (31) and the second boundary (52) of the lower surface on both sides of the crystalline silicon solar cell (20) in the horizontal moving direction and the area formed by the second edge (32) and the third boundary (53) of the lower surface on both sides of the crystalline silicon solar cell (20) in the horizontal moving direction do not have physical contact; or, to insulate the areas in physical contact between the area between the first edge (31) and the second boundary (52) of the lower surface on both sides of the crystalline silicon solar cell (20) in the horizontal moving direction and the area formed by the second edge (32) and the third boundary (53) of the lower surface on both sides of the crystalline silicon solar cell (20) in the horizontal moving direction and the area formed by the second edge (32) and the third boundary (53) of the lower surface on both sides of the crystalline silicon solar cell (20) in the horizontal moving direction and the area formed by the second edge (32) and the third boundary (53) of the lower surface on both sides of the crystalline silicon solar cell (20) in the horizontal moving direction.

8. The apparatus for electroplating cathode electrical contacts according to claim 6 or 7, characterized in that, The width between the first boundary (51) and the second boundary (52) of the non-conductive region of the conductive transmission roller (10) and between the third boundary (53) and the fourth boundary (54) is 1 to 40 mm.

9. The apparatus for electroplating cathode electrical contacts according to claim 6 or 7, characterized in that, An insulating roller (40) is located above the conductive transmission roller (10).

10. An apparatus for electroplating cathode electrical contacts according to claim 6 or 7, characterized in that, Before performing horizontal double-sided electroplating on the crystalline silicon solar cell (20), a pretreatment process is performed on the electroplating surface of the crystalline silicon solar cell, and after performing horizontal double-sided electroplating on the crystalline silicon solar cell (20), a cleaning and drying process is performed.

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