Crease-resistant encapsulation structure for solar substrates

Abstract

The application relates to a wrinkle-proof packaging structure of a solar substrate, which comprises a soft solar substrate, an inner packaging layer and an outer reinforcing layer. The soft solar substrate is sequentially stacked with a soft transparent substrate, a lower conductive layer, an electrode wire, a photovoltaic layer and an upper conductive layer. The inner packaging layer comprises transparent packaging glue, an upper inner packaging layer and a lower inner packaging layer, and the soft solar substrate is packaged in the transparent packaging glue, the upper inner packaging layer and the lower inner packaging layer. The outer reinforcing layer comprises filling packaging glue, an upper outer reinforcing layer and a lower outer reinforcing layer, and the inner packaging layer is packaged in the filling packaging glue, the upper outer reinforcing layer and the lower outer reinforcing layer. A pattern layer is formed on the surface of the outer reinforcing layer, so that the occurrence of surface wrinkles can be reduced. Meanwhile, the multilayer packaging structure can improve the weather resistance and water and gas resistance of the soft solar substrate.

Description

[0001] This application claims priority to Taiwan Patent Application No. 114206609, filed on June 26, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to a solar cell, and more particularly to a wrinkle-resistant encapsulation structure for a solar substrate that can improve weather resistance, water and gas barrier properties, and wrinkle-resistant design. Background Technology

[0003] Flexible solar cells are widely used in portable electronic devices, wearable technologies, and building-integrated photovoltaics (BIPV) due to their thinness, lightness, and flexibility. However, traditional packaging structures often use a separate packaging method for each cell (i.e., outer EVA or ETFE encapsulating inner solar modules), resulting in high material costs and lengthy manufacturing processes. Switching to a multi-cell packaging method (outer layer encapsulating multiple inner solar modules) followed by cutting can simplify the process, reduce costs, and shorten processing time.

[0004] However, due to the material characteristics of the outer reinforcing layer, it often softens during the encapsulation process due to heating. When encapsulating multiple solar modules, the increased area due to the multiple solar modules can lead to gaps or unevenness between adjacent solar modules within the encapsulation, which can easily cause surface wrinkles after cooling. The larger the encapsulation area, the more likely this phenomenon is to occur. Utility Model Content

[0005] Therefore, the main objective of this application is to provide a wrinkle-resistant encapsulation structure for a flexible solar substrate, wherein the outer reinforcing layer can form a microstructure pattern on the surface during the encapsulation process, which can reduce the occurrence of surface wrinkles.

[0006] Another objective of this application is to arrange multiple already encapsulated flexible solar substrates with inner encapsulation layers in parallel in a rectangular direction, sharing a large outer reinforcing layer for encapsulation, and then cutting them after encapsulation, which can save and simplify operation costs.

[0007] To achieve the above objectives, this application provides a multilayer encapsulation structure for a solar substrate, comprising: a flexible solar substrate, an inner encapsulation layer, and an outer reinforcement layer. The flexible solar substrate includes: a flexible transparent substrate, a lower conductive layer, electrode wires, a photovoltaic layer, and an upper conductive layer; the lower conductive layer, the electrode wires, the photovoltaic layer, and the upper conductive layer are sequentially stacked on one side surface of the flexible transparent substrate. The inner encapsulation layer includes: a transparent encapsulant, an upper inner encapsulation layer, and a lower inner encapsulation layer; the flexible solar substrate is encapsulated therebetween by the transparent encapsulant, the upper inner encapsulation layer, and the lower inner encapsulation layer. The outer reinforcement layer includes: a filling encapsulant, an upper outer reinforcement layer, and a lower outer reinforcement layer; the inner encapsulation layer is encapsulated therebetween by the filling encapsulant, the upper outer reinforcement layer, and the lower outer reinforcement layer. Each of the upper and lower outer reinforcement layers has a patterned layer on its surface.

[0008] In one embodiment of this application, the pattern layer is a diamond pattern.

[0009] In one embodiment of this application, the lower conductive layer and the electrode wire are disposed on one side surface of the flexible transparent substrate; the photovoltaic layer is composed of a plurality of photovoltaic units, each photovoltaic unit is disposed on one side surface of the lower conductive layer and the electrode wire, and a gap is formed between each photovoltaic unit; the upper conductive layer is disposed on one side surface of each photovoltaic unit, and the upper conductive layer of each photovoltaic unit is electrically connected in series with the lower conductive layer of another photovoltaic unit.

[0010] In one embodiment of this application, the lower conductive layer is electrically connected to the outside via the electrode wire, and the electrode wire is a flat cable connection area.

[0011] In one embodiment of this application, the photovoltaic layer sequentially comprises an electron transport layer, an active layer, and a hole transport layer, or the photovoltaic layer sequentially comprises the hole transport layer, the active layer, and the electron transport layer disposed on one side surface of the lower conductive layer.

[0012] In one embodiment of this application, the photovoltaic layer is an organic photovoltaic cell, a perovskite photovoltaic cell, or a copper indium gallium selenide thin-film photovoltaic cell.

[0013] In one embodiment of this application, a through hole is provided on one side of the upper inner encapsulation layer corresponding to the position of the electrode wire and the lower conductive layer, and the through hole provides electrical connection between the electrode wire and the outside.

[0014] In one embodiment of this application, the flexible solar substrate, after being encapsulated in the inner encapsulation layer, has a thickness of 50 μm to 1 mm.

[0015] In one embodiment of this application, a through hole is also provided on one side of the upper outer reinforcing layer corresponding to the through hole position of the upper inner encapsulation layer, providing electrical connection between the electrode wires of the flexible solar substrate and the outside.

[0016] In one embodiment of this application, the outer reinforcing layer covers the outside of the inner encapsulation layer and has a thickness of 50um-5mm.

[0017] In one embodiment of this application, a plurality of inner encapsulation layers are arranged between the upper outer reinforcing layer and the lower outer reinforcing layer of the large-area outer reinforcing layer, and the filler encapsulant is disposed between the upper outer reinforcing layer and the lower outer reinforcing layer. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a semi-finished flexible solar cell substrate according to the first embodiment of this application;

[0019] Figure 2 for Figure 1 A schematic diagram of a flexible solar substrate semi-finished product encapsulated in an inner encapsulation layer;

[0020] Figure 3 for Figure 2 Schematic diagram of inner encapsulation layer encapsulated in outer reinforcement layer

[0021] Figure 4 This is a schematic diagram of the embossing process performed on the surface of the outer encapsulation layer according to the second embodiment of this application;

[0022] Figure 5 for Figure 4 A top-view diagram;

[0023] Figure 6 The third embodiment of this application is as follows: Figure 2 A side view diagram showing multiple inner encapsulation layers encapsulated within a large-area outer reinforcement layer;

[0024] Figure 7 for Figure 6 A top-view diagram.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1: Flexible solar panel substrate;

[0027] 11: Flexible transparent substrate;

[0028] 12: Lower conductive layer;

[0029] 13: Electrode wires;

[0030] 14: Photovoltaic layer;

[0031] 14a: Photovoltaic unit;

[0032] 15: Upper conductive layer;

[0033] 2: Inner encapsulation layer;

[0034] 21: Transparent encapsulating adhesive;

[0035] 22: Upper inner encapsulation layer;

[0036] 23: Lower inner encapsulation layer;

[0037] 24: Through hole;

[0038] 3, 3a: Outer reinforcement layer;

[0039] 31, 31a: Filler encapsulant;

[0040] 32, 32a: Upper outer reinforcement layer;

[0041] 33, 33a: Lower outer reinforcement layer;

[0042] 34: Through hole;

[0043] 4: Pattern layer. Detailed Implementation

[0044] The technical content and detailed description of this application are explained below with reference to the accompanying drawings:

[0045] Please see Figure 1 This is a schematic diagram of a semi-finished flexible solar substrate according to the first embodiment of this application. As shown in the figure: the anti-wrinkle packaging structure of the solar substrate of this application includes at least a flexible solar substrate 1, which includes: a flexible transparent substrate 11, a lower conductive layer 12, an electrode wire 13, a photovoltaic layer 14, and an upper conductive layer 15.

[0046] In the fabrication of the flexible solar substrate 1, a flexible transparent substrate 11 is first provided, wherein the flexible transparent substrate 11 is polyimide (PI), polyethylene terephthalate (PEN), or polyethylene terephthalate (PET).

[0047] A lower conductive layer 12 and electrode wires 13 are formed on one side surface of the flexible transparent substrate 11 by silver paste coating and printing or by indium tin oxide (ITO) sputtering or evaporation. In the embodiments of this application, the lower conductive layer 12 is electrically connected to the outside via the electrode wires 13, which can be fabricated as a flat cable connection area.

[0048] After the lower conductive layer 12 and the electrode wire 13 are fabricated as described above, a photovoltaic layer 14 is coated and fabricated on the side surface of the lower conductive layer 12. In the embodiments of this application, the photovoltaic layer 14 sequentially includes an electron transport layer (not shown), an active layer (not shown), and a hole transport layer (not shown), or the photovoltaic layer 14 sequentially includes a hole transport layer (not shown), an active layer (not shown), and an electron transport layer (not shown) disposed on one side surface of the lower conductive layer 12.

[0049] More notably, the photovoltaic layer 14 of this application can be an organic photovoltaic cell (OPV), a perovskite solar cell (PSC), or a copper indium gallium diselenide (CIGS) thin-film photovoltaic cell. However, organic photovoltaic cells (OPV) are preferred.

[0050] Next, processing is carried out in this application. Laser etching is performed with a specific laser energy in a manner that does not damage the flexible transparent substrate 11 to etch the photovoltaic layer 14 and the lower conductive layer 12 to form a plurality of photovoltaic units 14a, with a gap 141a formed between each photovoltaic unit 14a.

[0051] Next, an upper conductive layer 15 is fabricated on the side surface of the photovoltaic layer 14 using silver paste coating printing or indium tin oxide (ITO) sputtering or evaporation combined with laser etching. This allows the upper conductive layer 15 of the photovoltaic unit 14a to be electrically connected to the lower conductive layer 12 of the second photovoltaic unit 14a, forming a series connection of multiple photovoltaic units 14a on the semi-finished flexible solar substrate 1.

[0052] Please see Figure 2 ,for Figure 1 A schematic diagram of a flexible solar substrate semi-finished product encapsulated in an inner encapsulation layer; see also [reference needed]. Figure 1 As shown in the figure: When the flexible solar substrate 1 semi-finished product of this application is encapsulated with the inner encapsulation layer 2, two pieces of upper inner encapsulation layer 22 and lower inner encapsulation layer 23 containing transparent encapsulating adhesive 21 are placed between them, and then the flexible solar substrate 1 is encapsulated therebetween. In the embodiments of this application, the upper inner encapsulation layer 22 and the lower inner encapsulation layer 23 are polymer layers with water and gas barrier properties. The polymer layer is polyethylene terephthalate (PET), polyethylene terephthalate (PEN) or a polymer composite material.

[0053] Next, the flexible solar substrate 1 is bonded together by vacuum hot pressing, so that it is encapsulated between the upper inner encapsulation layer 22 and the lower inner encapsulation layer 23.

[0054] Finally, through holes 24 are provided on one side of the upper inner encapsulation layer 22, corresponding to the positions of the electrode wires 13 and the lower conductive layer 12. These through holes 24 provide electrical connection between the electrode wires 13 of the flexible solar substrate 1 and an external control device (not shown in the figure). Furthermore, after the flexible solar substrate 1 of this application is encapsulated in the inner encapsulation layer 2, its thickness is 50 μm to 1 mm. In this figure, the transparent encapsulant 21 is a thermosetting epoxy resin, a thermoplastic ethylene-vinyl acetate copolymer (EVA), a thermoplastic polyolefin elastomer (POE), or a photocurable acrylic resin.

[0055] Please see Figure 3 ,for Figure 2 A schematic diagram showing the inner encapsulation layer encapsulated within the outer reinforcement layer; see also [reference needed]. Figures 1-2 As shown in the figure: After the flexible solar substrate 1 is encapsulated by the inner encapsulation layer 2 in this application, the outer reinforcement layer 3 structure is prepared. Two upper outer reinforcement layers 32 and lower outer reinforcement layers 33, each containing a filling encapsulant 31, are placed between them, and the aforementioned inner encapsulation layer 2 structure is encapsulated therebetween. In this example, the upper outer reinforcement layer 32 and the lower outer reinforcement layer 33 are fluoroplastic film (Ethylene tetrafluoroethylene, ETFE), fluorinated ethylene propylene copolymer (FEP), polyethylene terephthalate (PET), polycarbonate (PC), or polymer composite materials.

[0056] Next, a through hole 34 is also provided on one side of the outer reinforcing layer 32 corresponding to the through hole 24 of the inner encapsulation layer 22, providing electrical connection between the electrode wires 13 of the flexible solar substrate 1 and an external control device (not shown in the figure). Then, it is bonded by vacuum hot pressing to complete this application. The outer reinforcing layer 3 covers the outside of the inner encapsulation layer 2, with a thickness of 50 μm (micrometer) to 5 mm (millimeters). In this figure, the filling encapsulant 31 is a thermosetting epoxy resin, thermoplastic ethylene-vinyl acetate copolymer (EVA), thermoplastic polyolefin elastomer (POE), or photocurable acrylic resin.

[0057] Please see Figure 4 , 5 This is a schematic diagram of the second embodiment of this application, showing the embossing treatment on the surface of the outer reinforcing layer. Figure 4 A top-view diagram; also refer to... Figures 1-3 As shown in the figure: In order to prevent wrinkles on the surface of the outer reinforcing layer 3 during vacuum heat bonding, this application attaches a release liner (not shown in the figure) of Teflon fiber cloth to the outer surface of the upper outer reinforcing layer 32 and the lower outer reinforcing layer 33. Originally, this release liner served as a barrier between the product and the surface of the vacuum heat-pressing equipment to prevent adhesion. However, this application specifically selects a 1x1mm cross-shaped woven Teflon fiber cloth. This allows the release liner to soften on the surface of the outer reinforcing layer 3 under vacuum high-temperature heat pressing. The release liner is a 1x1mm cross-shaped woven checkered pattern layer 4. After cooling under vacuum heat pressing, the pattern layer 4 forms a cross-shaped diamond pattern protrusion. This can mitigate the formation of unexpected wrinkles in the outer reinforcing layer 3 due to thermal expansion and contraction.

[0058] Please see Figure 6 , 7 The third embodiment of this application is as follows: Figure 2 Multiple inner encapsulation layers are encapsulated within a large-area outer reinforcement layer. (Side view diagram and...) Figure 6 The diagram is shown from the top. In the embodiments of this application, multiple inner encapsulation layers 2 are arranged between the upper outer reinforcing layer 32a and the lower outer reinforcing layer 33a of the large-area outer reinforcing layer 3a. A filling encapsulant 31a is then inserted between the upper outer reinforcing layer 32a and the lower outer reinforcing layer 33a, and the layers are vacuum-pressed together. The solar substrate is then cut to the required size.

[0059] Test results:

[0060] The wrinkle-resistant packaging structure prepared in the above embodiments was subjected to relevant tests, and the results showed that:

[0061] 1. Mechanical strength test: Impact, bending and scratch tests were conducted. The surface damage of the flexible solar substrate (cell) with the anti-wrinkle encapsulation structure of this application was significantly reduced compared with the flexible solar substrate (cell) without the pattern layer (diamond pattern) 4 design, which shows that this application has better mechanical protection effect.

[0062] 2. Optical property test: The transmittance test was conducted. The wrinkle-resistant packaging structure with the double-layer packaging structure of this application showed that the difference in visible light transmittance between it and the unpackaged solar substrate was within 0.5%, indicating that this application maintains good transparency and light transmittance.

[0063] 3. Weather resistance and optoelectronic performance testing: including accelerated aging test (85℃ / 85%RH, 480 hours), water vapor penetration test (ASTM F1249) and mechanical strength test, meeting the defined standards of environmental requirements, which can ensure that the packaging quality meets the usage requirements.

[0064] In summary, the anti-wrinkle encapsulation structure of the solar substrate (cell) provided in this application effectively improves the environmental weather resistance, mechanical strength and long-term reliability of the flexible solar substrate (cell) through the water and gas barrier function of the inner encapsulation layer 2 and the mechanical protection function of the anti-wrinkle grid (diamond pattern) 4 raised structure on the surface of the outer reinforcing layer 3, while maintaining its thin and flexible characteristics, making it more suitable for diverse application fields such as portable electronic devices, wearable technology, and building integrated photovoltaic (BIPV).

[0065] However, the above description is only a preferred embodiment of this application and is not intended to limit the scope of patent protection of this application. Therefore, all equivalent changes made based on the content of this application's specification or drawings are similarly included within the scope of protection of this application and are hereby stated.

Claims

1. A wrinkle-resistant encapsulation structure for a solar cell substrate, characterized in that, Include: A flexible solar cell substrate includes: a flexible transparent substrate, a lower conductive layer, electrode wires, a photovoltaic layer, and an upper conductive layer; the lower conductive layer, the electrode wires, the photovoltaic layer, and the upper conductive layer are sequentially stacked on the side surface of the flexible transparent substrate. The inner encapsulation layer comprises: a transparent encapsulating adhesive, an upper inner encapsulation layer, and a lower inner encapsulation layer; the flexible solar substrate is encapsulated therebetween by the transparent encapsulating adhesive, the upper inner encapsulation layer, and the lower inner encapsulation layer. and An outer reinforcing layer comprises: a filling encapsulant, an upper outer reinforcing layer, and a lower outer reinforcing layer; the inner encapsulant layer is encapsulated therebetween by the filling encapsulant, the upper outer reinforcing layer, and the lower outer reinforcing layer; The upper outer reinforcing layer and the lower outer reinforcing layer each have a patterned layer on their surfaces.

2. The anti-wrinkle packaging structure for a solar substrate as described in claim 1, characterized in that, The patterned layer has a diamond pattern.

3. The anti-wrinkle packaging structure for a solar substrate as described in claim 1, characterized in that, The lower conductive layer and the electrode wires are disposed on the side surface of the flexible transparent substrate; the photovoltaic layer is composed of multiple photovoltaic units, each photovoltaic unit is disposed on the side surface of the lower conductive layer and the electrode wires, and a gap is formed between each photovoltaic unit; the upper conductive layer is disposed on the side surface of each photovoltaic unit, and the upper conductive layer of each photovoltaic unit is electrically connected in series with the lower conductive layer of another photovoltaic unit.

4. The anti-wrinkle packaging structure for a solar substrate as described in claim 1, characterized in that, The lower conductive layer is electrically connected to the outside via the electrode wires, which are flat cable connection areas.

5. The anti-wrinkle packaging structure for a solar substrate as described in claim 1, characterized in that, The photovoltaic layer sequentially comprises an electron transport layer, an active layer, and a hole transport layer, or the photovoltaic layer sequentially comprises the hole transport layer, the active layer, and the electron transport layer disposed on the side surface of the lower conductive layer.

6. The anti-wrinkle packaging structure for a solar substrate as described in claim 1, characterized in that, The photovoltaic layer is an organic photovoltaic cell, a perovskite photovoltaic cell, or a copper indium gallium selenide thin-film photovoltaic cell.

7. The anti-wrinkle packaging structure for a solar substrate as described in claim 1, characterized in that, A through hole is provided on one side of the upper inner encapsulation layer corresponding to the position of the electrode wire and the lower conductive layer, and the through hole provides electrical connection between the electrode wire and the outside.

8. The anti-wrinkle packaging structure for a solar substrate as described in claim 7, characterized in that, A through hole is also provided on one side of the upper outer reinforcing layer corresponding to the through hole position of the upper inner encapsulation layer, providing electrical connection between the electrode wires of the flexible solar substrate and the outside.

9. The anti-wrinkle packaging structure for a solar substrate as described in claim 1, characterized in that, The flexible solar substrate, after being encapsulated in the inner encapsulation layer, has a thickness of 50µm to 1mm.

10. The anti-wrinkle packaging structure for a solar substrate as described in claim 1, characterized in that, The outer reinforcing layer covers the outside of the inner encapsulation layer and has a thickness of 50um-5mm.

11. The anti-wrinkle packaging structure for a solar substrate as described in claim 1, characterized in that, Multiple inner encapsulation layers are arranged between the upper and lower outer reinforcing layers of the large-area outer reinforcing layer, and the filler encapsulant is applied between the upper and lower outer reinforcing layers.

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