A glue-free fixing and separation method for a temporary substrate of a flexible gallium arsenide solar cell

Abstract

The present invention provides a method for fixing and separating a temporary substrate of a flexible gallium arsenide solar cell without glue, comprising the steps of: S1, constructing an outer welding layer 1 on a temporary substrate; S2, welding the outer welding layer 1 to the back electrode of a wafer by laser welding technology; S3, peeling off the wafer substrate and continuing to prepare the battery device; S4, separating adjacent flexible gallium arsenide solar cell monomers by laser cutting technology; wherein the outer welding layer 1 includes at least one group of closed path belts, and all flexible gallium arsenide solar cell monomers are located on the inner side of the closed path belts. The method for fixing and separating a temporary substrate without glue provided by the present invention can avoid the introduction of volatile organic adhesive components in the preparation process of flexible gallium arsenide solar cells, can effectively improve the stability of the battery preparation process, and ensure the preparation efficiency and preparation quality of the battery. The closed path belt in the outer welding layer 1 can avoid chemical corrosion on the back electrode side, and ensure the preparation quality of the battery.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor manufacturing, and in particular to a method for fixing and separating a temporary substrate of a flexible gallium arsenide solar cell without adhesive. Background Art

[0002] The preparation method of flexible gallium arsenide solar cells is usually: epitaxy is carried out on a 4-inch or 6-inch wafer substrate, after preparing a single-side electrode, a temporary substrate is bonded, the wafer substrate is peeled off, the semiconductor device preparation on the other side is completed, and finally the device is separated from the temporary substrate and processed into a single cell.

[0003] At the current level of technology, temporary substrates are usually fixed by bonding, and different debonding methods are used according to different colloids, such as: using laser irradiation to cause the adhesive to denature and debond, or using an organic solvent soaking method to dissolve and remove the adhesive, or using a buffer pad to isolate the adhesive (Chinese patent number 2022116506380). The above methods of bonding temporary substrates all introduce organic components, which will accompany all subsequent semiconductor processes before separating the battery. Due to its easy volatility, it is easy to cause process instability, which has a serious impact on the efficiency and quality of battery preparation. Summary of the invention

[0004] The object of the present invention is to provide a method for fixing and separating a temporary substrate of a flexible gallium arsenide solar cell without adhesive, so as to solve the problems in the above-mentioned background technology.

[0005] The technical solution adopted by the present invention is: a method for fixing and separating a temporary substrate of a flexible gallium arsenide solar cell without adhesive, which comprises the following steps:

[0006] S1, constructing an outer solder layer 1 on a temporary substrate;

[0007] S2, welding the outer welding layer 1 to the back electrode of the wafer using laser welding technology;

[0008] S3, peeling off the wafer substrate and continuing with the battery device preparation;

[0009] S4, using laser cutting technology to separate adjacent flexible GaAs solar cell monomers;

[0010] The outer solder layer 1 at least includes a group of closed path belts, and all the flexible gallium arsenide solar cell monomers are located inside the closed path belts.

[0011] Preferably, the outer solder layer 1 further includes a plurality of reinforced solder portions, and the reinforced solder portions are located in the gaps between adjacent flexible gallium arsenide solar cell monomers.

[0012] Preferably, the reinforced weld portion includes at least one of a reinforced weld point, a reinforced weld line and a reinforced weld strip.

[0013] Preferably, the temporary substrate is a transparent temporary substrate.

[0014] Preferably, the back electrode comprises a flexible support layer and a plurality of metal electrode layers stacked in sequence, and the flexible support layer is connected to the first outer welding layer.

[0015] Preferably, the flexible support layer is a flexible metal support layer or a flexible polymer support layer, and a second outer welding layer is arranged on a side of the flexible polymer support layer away from the metal electrode layer, and the shape of the second outer welding layer is the same as that of the first outer welding layer.

[0016] Preferably, the materials of the outer solder layer 1 and the outer solder layer 2 are independently selected from one of Al, Ag, Cu, Ti and Fe.

[0017] Preferably, the outer solder layer is constructed on the temporary substrate by screen printing or magnetron sputtering.

[0018] The present invention has the following beneficial effects: the adhesive-free fixing and separation method of the temporary substrate provided by the present invention can avoid the introduction of volatile organic adhesive components in the preparation process of the flexible gallium arsenide solar cell, effectively improve the stability of the cell preparation process, and ensure the preparation efficiency and preparation quality of the cell. The closed path belt in the outer solder layer 1 can avoid chemical corrosion on the back electrode side, and ensure the preparation quality of the cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of a main view of step S1 in an embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of a main view of step S2 in an embodiment of the present invention;

[0021] Figure 3 is a schematic diagram of a main view of step S3 in an embodiment of the present invention;

[0022] Figure 4 is a schematic diagram of a main view of step S4 in an embodiment of the present invention;

[0023] Figure 5 It is a bottom view schematic diagram of a temporary substrate and a top view schematic diagram of a flexible gallium arsenide solar cell monomer in an embodiment of the present invention.

[0024] In the figure:

[0025] 1. Temporary substrate;

[0026] 2. Outer welding layer 1; 21. Closed path belt; 22. Reinforced welding part;

[0027] 3. Back electrode; 31. Flexible support layer; 32. Metal electrode layer;

[0028] 4. Wafer substrate;

[0029] 5. Wafer epitaxial layer;

[0030] 6. External welding layer 2;

[0031] 7. Flexible gallium arsenide solar cell monomer. DETAILED DESCRIPTION

[0032] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0033] Reference Figure 1-5 The embodiment of the present invention provides a method for fixing and separating a temporary substrate of a flexible gallium arsenide solar cell without adhesive, comprising the steps of:

[0034] S1, constructing an outer solder layer 2 on a temporary substrate 1;

[0035] S2, using laser welding technology to weld the outer welding layer 2 to the back electrode 3 of the wafer;

[0036] S3, peeling off the wafer substrate 4, and continuing to prepare the battery device;

[0037] S4, separating adjacent flexible gallium arsenide solar cell monomers 7 using laser cutting technology;

[0038] Among them, the outer welding layer 2 includes at least one group of closed path belts 21, and all the flexible gallium arsenide solar cell monomers 7 are located on the inner side of the closed path belt 21, so that after the outer welding layer 2 is welded to the back electrode 3 of the wafer, the area inside the closed path belt 21 is closed, and will not be penetrated or infiltrated by various liquid reagents in the battery device preparation process in step S3, thereby avoiding chemical corrosion on the back electrode 3 side and ensuring the preparation quality of the battery.

[0039] Due to the support and connection of the outer solder layer 2, the stability of the wafer epitaxial layer 5 in step S3 can be guaranteed, and the connection part between the closed path belt 21 and the back electrode 3 of the wafer is constructed on the outside of all flexible gallium arsenide solar cell monomers 7, and is not directly connected to the part where any flexible gallium arsenide solar cell monomer 7 is located. When the laser cutting technology is used to cut the gap between adjacent flexible gallium arsenide solar cell monomers 7, not only the outside of the flexible gallium arsenide solar cell monomer 7 is separated from the wafer, but also the temporary substrate 1 corresponding to the monomer is separated from the remaining temporary substrates 1, and the flexible gallium arsenide solar cell monomer 7 is automatically separated from the cut temporary substrate 1 fragments.

[0040] The above-mentioned glue-free fixing and separation method of the temporary substrate 1 can avoid the introduction of volatile organic adhesive components in the preparation process of the flexible gallium arsenide solar cell, which can effectively improve the stability of the cell preparation process and ensure the preparation efficiency and quality of the cell.

[0041] In this embodiment, the outer solder layer 2 also includes a plurality of reinforcing solder portions 22, which are located in the gaps between adjacent flexible gallium arsenide solar cell monomers 7, and are used to provide more support for the wafer epitaxial wafer and improve the stability in step S3. Similarly, the reinforcing solder portions 22 are not directly connected to any part of the flexible gallium arsenide solar cell monomer 7, and will not cause the flexible gallium arsenide solar cell monomer 7 to be unable to be separated from the outer solder layer 2 or the temporary substrate 1.

[0042] More specifically, the reinforced weld portion 22 may include any one or a combination of reinforced weld points, reinforced weld lines and reinforced weld strips, and may also be graphically designed as required.

[0043] In order to facilitate the smooth implementation of laser welding and laser cutting, the temporary substrate 1 in this embodiment adopts a transparent temporary substrate 1.

[0044] Generally speaking, the back electrode 3 includes a flexible support layer 31 and a plurality of metal electrode layers 32 stacked in sequence. In this embodiment, the flexible support layer 31 is directly connected to the outer solder layer 1 2. According to specific needs, the flexible support layer 31 can be a flexible metal support layer or a flexible polymer support layer. If a flexible polymer support layer is selected, an outer solder layer 2 6 is required to be constructed on the side of the flexible polymer support layer away from the metal electrode layer 32. The shape of the outer solder layer 2 6 is the same as that of the outer solder layer 1 2 to ensure that the wafer epitaxial layer 5 and the temporary substrate 1 can be effectively welded and connected.

[0045] More specifically, the materials of the outer solder layer 1 2 and the outer solder layer 2 6 are independently selected from one of Al, Ag, Cu, Ti and Fe, preferably Al, and can be constructed by screen printing or magnetron sputtering, and the thickness should be less than 100 μm.

[0046] It is worth noting that when designing the shapes of the outer solder layer 1 2 and the outer solder layer 2 6, it should be ensured that the outer solder layer 1 2 and the outer solder layer 2 6 do not overlap with any part of the flexible gallium arsenide solar cell monomer 7. When connecting the temporary substrate 1 and the wafer epitaxial layer 5, the two need to be completely aligned and compacted to minimize the residual gas inside the closed path belt 21.

[0047] The following is a specific implementation example of the present invention.

[0048] The process of preparing flexible GaAs solar cells:

[0049] (1) Using a vacuum evaporation process, a plurality of metal electrode layers 32 are prepared on the epitaxial layer 5 of the flexible GaAs solar cell wafer, specifically including an adhesive Ti layer and a conductive Ag layer, the thickness of which are 100 nm and 3 μm respectively;

[0050] (2) using an electroplating process, electroplating a flexible support layer 31 (Cu) and an outer solder layer 26 (Ag) on ​​the surface of the conductive Ag layer, the thicknesses of which are 20 μm and 100 nm respectively;

[0051] (3) The temporary substrate 1 is made of glass with a thickness of 500 μm, and an external solder layer 2 (Ag) is formed on its surface. The thickness of the external solder layer 2 is 1 μm;

[0052] (4) Align the outer solder layer 1 2 and the outer solder layer 2 6, compact the wafer epitaxial layer 5 and the temporary substrate 1, the pressure is 100000 Pa, and weld them using laser welding technology;

[0053] (5) peeling off the wafer substrate 4, and continuing to prepare the battery device to prepare a flexible gallium arsenide solar battery device with full performance;

[0054] (6) Adjacent flexible GaAs solar cell monomers 7 are separated by laser cutting technology. After cutting, the flexible GaAs solar cell monomers 7 are automatically separated from the temporary substrate 1 .

[0055] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the claims attached to the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the claims, or the equivalent forms of such scope and boundaries.

Claims

1. A method for fixing and separating a temporary substrate of a flexible gallium arsenide solar cell without adhesive, characterized in that: Includes steps: S1, constructing an outer solder layer 1 on a temporary substrate; S2, welding the outer welding layer 1 to the back electrode of the wafer using laser welding technology; S3, peeling off the wafer substrate and continuing with the battery device preparation; S4, using laser cutting technology to separate adjacent flexible GaAs solar cell monomers; The outer solder layer 1 at least includes a group of closed path belts, and all the flexible gallium arsenide solar cell monomers are located inside the closed path belts.

2. The method for fixing and separating a temporary substrate of a flexible gallium arsenide solar cell without adhesive according to claim 1, characterized in that: The outer solder layer 1 also includes a plurality of reinforced solder portions, which are located in the gaps between adjacent flexible gallium arsenide solar cell monomers.

3. The method for adhesive-free fixing and separation of a temporary substrate of a flexible gallium arsenide solar cell according to claim 2, characterized in that: The reinforced weld portion includes at least one of a reinforced weld point, a reinforced weld line, and a reinforced weld strip.

4. The method for fixing and separating a temporary substrate of a flexible gallium arsenide solar cell without adhesive according to any one of claims 1 to 3, characterized in that: The temporary substrate is a transparent temporary substrate.

5. The method for adhesive-free fixing and separation of a temporary substrate of a flexible gallium arsenide solar cell according to claim 4, characterized in that: The back electrode comprises a flexible support layer and a plurality of metal electrode layers stacked in sequence, and the flexible support layer is connected to the first outer welding layer.

6. The method for adhesive-free fixing and separation of a temporary substrate of a flexible gallium arsenide solar cell according to claim 5, characterized in that: The flexible support layer is a flexible metal support layer or a flexible polymer support layer. A second outer welding layer is arranged on the side of the flexible polymer support layer away from the metal electrode layer. The shape of the second outer welding layer is the same as that of the first outer welding layer.

7. The method for adhesive-free fixing and separation of a temporary substrate of a flexible gallium arsenide solar cell according to claim 6, characterized in that: The materials of the outer solder layer 1 and the outer solder layer 2 are independently selected from one of Al, Ag, Cu, Ti and Fe.

8. The method for adhesive-free fixing and separation of a temporary substrate of a flexible gallium arsenide solar cell according to claim 6 or 7, characterized in that: The outer solder layer is constructed on a temporary substrate by screen printing or magnetron sputtering.

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