solar cell module

Abstract

To provide a solar cell module having high stretchability and flexibility.SOLUTION: A solar cell module 100A includes: a stretchable resin base material 10A; a plurality of solar cells 20A having an elongation rate of 1% or less on the surface of the stretchable resin base material 10A; and a stretchable electrode which is formed in a pattern for electrically connecting the plurality of solar cells 20A.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a solar cell module. [Background technology]

[0002] In recent years, with the development of flexible sensors, wearable devices capable of managing physical condition have been attracting attention. Wearable devices are expected to be used in a wide range of applications in the fields of sports science and healthcare, such as those embedded in clothing or attached directly to the skin, to measure and monitor specific body parts. Because human skin expands and contracts repeatedly on a daily basis, if a wearable device is required to be worn without stress, it is desirable for the device to have stretchability corresponding to the object being worn. Furthermore, it is desirable for wearable devices to have a certain level of strength to withstand stresses generated when bending or rolling, taking into account handling and human movement. In this specification, devices with such characteristics are referred to as stretchable devices, regardless of their intended use.

[0003] Unless flexible sensors are sufficiently thin, bending them places stress on areas other than the vertical center, making the sensor vulnerable to breakage. Furthermore, sensors attached to stretchable cover sheets such as Saran Wrap (registered trademark) desirably have the same stretchability as the cover sheet so that the cover sheet can be stretched after the sensor is attached. Differences in stretchability and strength can lead to peeling at those points. To create a sensor that can accommodate stretchability, it is preferable to make the sensor itself stretchable, or to make the sensor small and thin so that it is less susceptible to stress, with a structure in which a stretchable material fills the gaps and allows it to be joined with a stretchable material.

[0004] A safe power source is needed to drive such stretchable sensors. It is also desirable for the power source to be stretchable. Therefore, it is considered appropriate to either make the cell itself stretchable, or to fabricate the cell by bonding a small, thin cell to a stretchable sheet. Organic solar cells (see, for example, Patent Documents 1 and 2) are known as solar cells whose cells themselves are stretchable, and thin solar cells are known as solar cells that can be made small and thin (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-125496 [Patent Document 2] Japanese Patent Application Publication No. 2020-019908 [Patent Document 3] Japanese Patent Application Publication No. 10-321883 Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Documents 1 and 2 describe substrates containing polyimide as substrates for organic solar cells.

[0007] Thin-film solar cells are generally flexible but lack sufficient flexibility and stretchability. When bonded to substrates or sensors of different thicknesses, the thickness of the substrate can cause stress in the vertical direction and away from the center, and flexibility alone does not provide sufficient flexibility and stretchability to release the stress. One potential solution would be solar cells mounted on stretchable substrates that are lightweight enough to provide a safe power source for clothing, human skin, animal skin, and electronics packaging.

[0008] The present invention has been made in view of the above circumstances, and provides a solar cell module that is highly stretchable and flexible. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides the following means.

[0010] A solar cell module according to a first aspect of the present invention comprises an elastic resin substrate, a plurality of solar cells having an elongation rate of 1% or less on the elastic resin substrate, and an elastic electrode formed in a pattern to electrically connect the plurality of solar cells.

[0011] In the solar cell module according to the above aspect, at least one of the first and second conduction electrodes of the solar cell may be joined to the stretchable electrode with a stretchable conductive adhesive.

[0012] The solar cell module according to the above aspect may have an expansion / contraction rate of 5% or more.

[0013] The solar cell module according to the above aspect may have a bend density of 0.05 bends / mm or more.

[0014] In the solar cell module according to the above aspect, the stretchable electrode may have a breaking expansion rate of 50% or more.

[0015] In the solar cell module according to the above aspect, the area occupied by the plurality of solar cells may be 10% or more of the total area of ​​the solar cell module.

[0016] The solar cell module according to the above aspect may include a sealing layer on at least one of the upper and lower surfaces of the solar cell.

[0017] A solar cell module according to a second aspect of the present invention comprises an elastic resin substrate, a solar cell having an elongation rate of 1% or less on the elastic resin substrate, and an elastic electrode electrically connecting the solar cell. [Effects of the Invention]

[0018] According to the solar cell module of the present invention, it is possible to provide a solar cell module that is highly stretchable and flexible. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic plan view showing a part of a solar cell module according to a first embodiment. [Figure 2] FIG. 2 is an exploded schematic cross-sectional view showing a cross section taken along II' in FIG. 1, with the solar cell, the stretchable resin substrate, and the stretchable electrode disassembled. [Figure 3] FIG. 2 is a schematic plan view showing the solar cell module shown in FIG. 1 with solar cells removed. [Figure 4] FIG. 10 is a schematic plan view showing a part of a solar cell module according to a second embodiment. [Figure 5] FIG. 10 is a schematic plan view showing a part of a solar cell module according to a third embodiment. [Figure 6] FIG. 1(a) is a cross-sectional view showing a schematic diagram of a double-sided electrode solar cell, and FIG. 1(b) is a cross-sectional view showing a schematic diagram of a back-side electrode solar cell. [Figure 7] FIG. 2 is an exploded cross-sectional view showing a solar cell, a stretchable conductive adhesive, a stretchable resin substrate, and a stretchable electrode. [Figure 8] 1A and 1B are conceptual diagrams for explaining the effects of the solar cell module according to the present invention, where FIG. 1A is a diagram showing a schematic diagram of the solar cell module according to the present invention, and FIG. 1B is a diagram for explaining the principle. [Figure 9] FIG. 10 is a conceptual diagram for explaining the effects. [Figure 10] 1 is a cross-sectional view of a solar cell module according to the present invention having a sealing layer. [Figure 11] 1A to 1C are process diagrams illustrating an example of a method for producing a solar cell module of the present invention. [Figure 12] 1 is a plan view showing the arrangement of solar cells according to Example 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention will be described in detail below with reference to the drawings as appropriate. The drawings used in the following description may show characteristic portions enlarged for the sake of clarity, and the dimensional proportions of each component may differ from the actual ones. The materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto. Appropriate changes can be made within the scope of the effects of the present invention.

[0021] (Solar cell module (first embodiment)) Fig. 1 is a plan view schematically showing a part of a solar cell module according to a first embodiment. Fig. 2 is an exploded cross-sectional view schematically showing a cross section taken along II' in Fig. 1, with the solar cell, the stretchable resin substrate, and the stretchable electrode disassembled. Fig. 3 is a plan view schematically showing the solar cell module shown in Fig. 1 with the solar cell removed.

[0022] The solar cell module 100 shown in Figure 1 comprises an elastic resin substrate 10, 15 individual solar cell pieces 20 with an elongation rate of 1% or less on the surface of the elastic resin substrate 10, and an elastic electrode 30 formed in a pattern to electrically connect the 15 individual solar cell pieces 20. In this specification, the "elongation" of a solar cell is |{(L-L0) / L0}×100| (L0: length of the solar cell in the tensile direction before testing, L: length at break). The "elongation" is evaluated as an absolute value. The "elongation" of a solar cell refers to the elongation in the direction in which the elongation is greatest.

[0023] The solar cell module according to the present invention preferably has an expansion / contraction rate of 5% or more. Here, in this specification, the "expansion rate" of a solar cell module is |{(LMe-LM) / LM}×100| (LM: length in a predetermined direction of the solar cell module when not expanding or contracting, LMe: length in a predetermined direction of the solar cell module when expanded or contracted). The "expansion rate" is evaluated as an absolute value. The expansion rate can be determined for each predetermined direction, but in this specification, "an expansion rate of the solar cell module of 5% or more" refers to the expansion rate in the direction with the highest expansion rate. If there is no anisotropy in the expansion rate, the expansion rate will be equal in all directions, and if the anisotropy in the expansion rate is small, the expansion rate will be close in all directions. Hereinafter, the "stretchable electrode" may be referred to as a stretchable electrode pattern.

[0024] Here, "individual solar cell" means that the solar cells are not connected to each other. Each solar cell is bonded to the stretchable resin substrate via a stretchable electrode, or via a stretchable electrode and a stretchable conductive adhesive (described later). Conventional solar cell modules have a structure in which multiple solar cells are connected to each other, and therefore do not stretch. In contrast, in the solar cell module according to the present invention, the multiple solar cells are not connected to each other, and each solar cell is bonded to the stretchable resin substrate via a stretchable electrode, or via a stretchable electrode and a stretchable conductive adhesive, so that the parts where the solar cells are not bonded can stretch, and the solar cell module as a whole has stretchability. If the solar cell module has an expansion rate of less than 5%, it is prone to breakage when bent or stretched.

[0025] Even if two solar cell modules can generate the same amount of power, a small type made up of a large number of solar cell cells will have a larger number of stretchable parts per unit length than a larger type made up of a fewer number of solar cell cells, and therefore a higher density of bending parts, allowing for finer deformation.In this specification, ``bending part density'' refers to the number of parts (bending parts) that can be bent per unit length.

[0026] The density of bends in the solar cell module according to the present invention is preferably 0.05 / mm or more. The bend density can be determined for each direction, but in this specification, "a bend density of 0.05 / mm or more in a solar cell module" refers to the bend density in the direction with the highest bend density. If there is no anisotropy in the bend density, the bend density will be the same in all directions, and if the anisotropy in the bend density is small, the bend density will be close in all directions.

[0027] The arrangement of the individual solar cells may be regular or irregular, or may be partly regular and partly irregular.

[0028] In the solar cell module 100 shown in FIG. 1, the 15 back electrode type solar cells 20 are arranged in the Y direction as multiple solar cell rows connected in series in the X direction, and the ends of the solar cell rows are connected to each other, so that the current path is electrically connected in series in a serpentine manner.

[0029] 2, each solar cell 20 has an electrode (hereinafter referred to as p-type electrode) 25 electrically connected to the p-type semiconductor, and an electrode 26 (hereinafter referred to as n-type electrode) electrically connected to the n-type semiconductor. The p-type electrode (first conductive electrode) 25 of each solar cell 20 is electrically connected to the n-type electrode (second conductive electrode) 26 of the next solar cell 20 via the stretchable electrode 30, and the p-type electrode 25 of one solar cell 20 is electrically connected to the n-type electrode 26 of the next solar cell 20 via the stretchable electrode 30, and so on. By alternately electrically connecting the p-type electrodes 25 and n-type electrodes 26 of each solar cell 20, the 15 individual solar cell pieces are connected in series.

[0030] 3, the stretchable electrode pattern 30 has an electrode pattern formed so that 15 individual solar cell pieces are connected in series. Specifically, for the 15 individual solar cell pieces, the stretchable electrode pattern 30 is made up of 14 spaced apart stretchable electrodes (30a to 30n) so that adjacent solar cell pieces are connected in order. In the solar cell module 100 according to the first embodiment, the stretchable electrode pattern 30 can have any electrode pattern shape as long as the pattern is formed so that the individual solar cell segments are connected in series. Also, even when the individual solar cell segments are connected in parallel, the stretchable electrode pattern 30 can have any electrode pattern shape accordingly.

[0031] (Solar cell module (second embodiment)) 4 is a schematic plan view showing a part of a solar cell module according to the second embodiment. The solar cell module according to the second embodiment differs from the solar cell module according to the first embodiment in that it includes a plurality of cell strings, each of which has a plurality of solar cells connected in series, and the stretchable electrode patterns are formed so that the cell strings are connected in series. A cell string is a series connection of solar cells.

[0032] The solar cell module 200 shown in Figure 4 comprises an elastic resin substrate 10, four cell strings 20L1 to 20L4 on the surface of the elastic resin substrate 10, each having solar cell cells 20 with an elongation rate of 1% or less connected in series, and an elastic electrode 30 formed in a pattern such that the solar cell cells 20 are connected in series by connecting adjacent cell strings 20L1 to 20L4 to each other in series.

[0033] The cell string 20L1 consists of five solar cells 20L11 to 20L15, and the n-type side electrode (or p-type side electrode) of the solar cell 20L11 is connected to the p-type side electrode (or n-type side electrode) of the solar cell 20L12, the n-type side electrode (or p-type side electrode) of the solar cell 20L12 is connected to the p-type side electrode (or n-type side electrode) of the solar cell 20L13, the n-type side electrode (or p-type side electrode) of the solar cell 20L13 is connected to the p-type side electrode (or n-type side electrode) of the solar cell 20L14, and the n-type side electrode (or p-type side electrode) of the solar cell 20L14 is connected to the p-type side electrode (or n-type side electrode) of the solar cell 20L15. In the cell string 20L2, the p-type side electrode (or n-type side electrode) of the solar cell 20L21 is connected to the n-type side electrode (or p-type side electrode) of the solar cell 20L22, the p-type side electrode (or n-type side electrode) of the solar cell 20L22 is connected to the n-type side electrode (or p-type side electrode) of the solar cell 20L23, the p-type side electrode (or n-type side electrode) of the solar cell 20L23 is connected to the n-type side electrode (or p-type side electrode) of the solar cell 20L24, and the p-type side electrode (or n-type side electrode) of the solar cell 20L24 is connected to the n-type side electrode (or p-type side electrode) of the solar cell 20L25. In the cell string 20L3, the n-type side electrode (or p-type side electrode) of the solar cell 20L31 is connected to the p-type side electrode (or n-type side electrode) of the solar cell 20L32, the n-type side electrode (or p-type side electrode) of the solar cell 20L32 is connected to the p-type side electrode (or n-type side electrode) of the solar cell 20L33, the n-type side electrode (or p-type side electrode) of the solar cell 20L33 is connected to the p-type side electrode (or n-type side electrode) of the solar cell 20L34, and the n-type side electrode (or p-type side electrode) of the solar cell 20L34 is connected to the p-type side electrode (or n-type side electrode) of the solar cell 20L35. In the cell string 20L4, the p-type side electrode (or n-type side electrode) of the solar cell 20L41 is connected to the n-type side electrode (or p-type side electrode) of the solar cell 20L42, the p-type side electrode (or n-type side electrode) of the solar cell 20L42 is connected to the n-type side electrode (or p-type side electrode) of the solar cell 20L43, the p-type side electrode (or n-type side electrode) of the solar cell 20L43 is connected to the n-type side electrode (or p-type side electrode) of the solar cell 20L44, and the p-type side electrode (or n-type side electrode) of the solar cell 20L44 is connected to the n-type side electrode (or p-type side electrode) of the solar cell 20L45.

[0034] The n-type electrode (or p-type electrode) of solar cell 20L15 and the p-type electrode (or n-type electrode) of solar cell 20L25 are connected via stretchable electrode 30A, thereby connecting cell strings 20L1 and 20L2 in series. The n-type electrode (or p-type electrode) of solar cell 20L21 and the p-type electrode (or n-type electrode) of solar cell 20L31 are connected via stretchable electrode 30B, thereby connecting cell strings 20L2 and 20L3 in series. The n-type electrode (or p-type electrode) of solar cell 20L35 and the p-type electrode (or n-type electrode) of solar cell 20L45 are connected via stretchable electrode 30C, thereby connecting cell strings 20L3 and 20L4 in series. In this case, by configuring the cell string so that only the first conductive electrode of the solar cell located at one end and the second conductive electrode of the solar cell located at the other end are exposed among the multiple solar cells that make up the cell string, the cell string can be attached to the stretchable resin substrate via the stretchable electrodes in the same way as individual solar cells.

[0035] In the solar cell module 200 according to the second embodiment, the stretchable electrode pattern 30 can have any electrode pattern shape as long as a desired connection pattern of the solar cells can be realized.

[0036] (Solar cell module (third embodiment)) 5 is a plan view schematically illustrating a portion of a solar cell module according to a third embodiment. The solar cell module according to the third embodiment differs from the solar cell module according to the first embodiment in that it includes a plurality of cell strings in which a plurality of solar cells are connected in series, and the stretchable electrode pattern is formed so that the cell strings are connected in parallel. The solar cell module according to the third embodiment is the same as the solar cell module according to the second embodiment in that it includes a plurality of cell strings in which a plurality of solar cells are connected in series, but differs from the solar cell module according to the second embodiment in that the stretchable electrode pattern is formed so that the cell strings are connected in parallel.

[0037] The solar cell module 300 shown in Figure 5 includes an elastic resin substrate 10, two cell strings 21L1 and 21L2 on the surface of the elastic resin substrate 10, in which solar cell cells 21 with an elongation rate of 1% or less are connected in series, and an elastic electrode 30 formed in a pattern that connects the solar cell cells 20 by connecting the cell strings 21L1 and 21L2 in parallel with each other.

[0038] The cell string 21L1 consists of five solar cell strings 21L11 to 21L15, and the n-type side electrode (or p-type side electrode) of the solar cell string 21L11 is connected to the p-type side electrode (or n-type side electrode) of the solar cell string 21L12, the n-type side electrode (or p-type side electrode) of the solar cell string 21L12 is connected to the p-type side electrode (or n-type side electrode) of the solar cell string 21L13, the n-type side electrode (or p-type side electrode) of the solar cell string 21L13 is connected to the p-type side electrode (or n-type side electrode) of the solar cell string 21L14, and the n-type side electrode (or p-type side electrode) of the solar cell string 21L14 is connected to the p-type side electrode (or n-type side electrode) of the solar cell string 21L15. The cell string 21L2 consists of five solar cell strings 21L21 to 21L25, and the n-type side electrode (or p-type side electrode) of the solar cell string 21L21 is connected to the p-type side electrode (or n-type side electrode) of the solar cell string 21L22, the n-type side electrode (or p-type side electrode) of the solar cell string 21L22 is connected to the p-type side electrode (or n-type side electrode) of the solar cell string 21L23, the n-type side electrode (or p-type side electrode) of the solar cell string 21L23 is connected to the p-type side electrode (or n-type side electrode) of the solar cell string 21L24, and the n-type side electrode (or p-type side electrode) of the solar cell string 21L24 is connected to the p-type side electrode (or n-type side electrode) of the solar cell string 21L25.

[0039] The p-type side electrode (or n-type side electrode) of solar cell 21L11 and the p-type side electrode (or n-type side electrode) of solar cell 21L21 are connected via an elastic electrode 30D, and the n-type side electrode (or p-type side electrode) of solar cell 21L15 and the n-type side electrode (or p-type side electrode) of solar cell 21L25 are connected via an elastic electrode 30E, and cell string 21L1 and cell string 21L2 are connected in parallel.

[0040] In the solar cell module 300 according to the third embodiment, the stretchable electrode pattern 30 can have any electrode pattern shape as long as a desired connection pattern of the solar cells can be realized.

[0041] A plurality of cell strings connected in series or in parallel is called a cell array. The solar cell can be attached to the stretchable resin substrate via a stretchable electrode as an individual solar cell, as a cell string consisting of a plurality of solar cells, as a cell array consisting of a plurality of cell strings, or as a combination of two or more of the individual solar cell, the cell string, and the cell array.

[0042] <Stretchable resin base material> The resin used in the stretchable resin substrate 10 used in the solar cell modules according to the first to third embodiments is not particularly limited, and any known stretchable resin can be used. Examples include epoxy resins, urethane resins, urea resins, polyurethane urea resins, methacrylic acid resins, polyacrylic resins, silicone resins, diene resins, polyester resins, polyether resins, polyamide resins, and polystyrene resins.

[0043] The resin used for the stretchable resin substrate 10 is preferably soluble in one or more solvents selected from N,N-dimethylacetamide (DMAc), methyl ethyl ketone (MEK), N,N-dimethylformamide (DMF), diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate (BCA), diethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, acetone, ethanol, methanol, ethyl lactate, butyl lactate, toluene, isopropyl alcohol, isobutyl alcohol, ethyl acetate, and butyl acetate.

[0044] The stretchable resin substrate 10 can be formed by applying and solidifying a resin composition containing the resin used in the stretchable resin substrate 10 and a solvent.

[0045] Among the above resins, urethane-based resins are preferred because they can be molded by simply coating and drying the resin composition without undergoing a curing reaction. If a resin requires a curing reaction, the composition and degree of cure may vary in the resin sheet if the curing reaction does not proceed uniformly, resulting in a resin sheet that does not have the desired elasticity, strength, and resistance to deterioration over time. Furthermore, when a urethane resin is used, it is preferable that the resin component contains a siloxane bond, because in this case the resin composition has appropriate water repellency and hydrolysis of the urethane bond is suppressed.

[0046] Hereinafter, the characteristics of the stretchable resin substrate 10 will be described while giving specific examples of resin compositions for producing the stretchable resin substrate 10. A specific example is a resin composition containing a resin component (sometimes referred to in this specification as "resin component (II)"), in which the resin component has a group represented by the following general formula (11), (21), or (31) and a urethane bond.

[0047] [ka] (In the formula, Z1 is an alkyl group, and one or more hydrogen atoms in the alkyl group may be substituted with a cyano group, a carboxy group, or a methoxycarbonyl group, and the two or more substituents may be the same or different. Z2 is an alkyl group. Z3 is an aryl group. R4 is a hydrogen atom or a halogen atom. The bond marked with an * is formed between the bond recipient of the group represented by general formula (11), (21), or (31).)

[0048] The resin component (II) contained in this resin composition has a urethane bond, and therefore has high flexibility. Resin component (II) is obtained by polymerization using a resin having a urethane bond and a polymerizable unsaturated bond and a RAFT agent for reversible addition-fragmentation chain transfer polymerization (hereinafter sometimes abbreviated as "RAFT polymerization"), from which the group represented by general formula (11), (21), or (31) is derived. By carrying out the polymerization reaction in this manner, gelation of the polymerized resin during the process of forming a crosslinked structure can be avoided, and a resin component with the desired degree of polymerization and crosslinked state can be obtained. In other words, resin component (II) having a group represented by general formula (11), (21), or (31) exhibits little variation in degree of polymerization and crosslinked state. Furthermore, the resin component (II) may have a siloxane bond, and in this case, the resin composition has appropriate water repellency and the hydrolysis of the urethane bond in the resin component (II) is suppressed. Such a resin component (II) can be obtained by carrying out a polymerization reaction using a resin having a siloxane bond and a polymerizable unsaturated bond. The method for producing the resin component (II) by RAFT polymerization will be described in detail separately.

[0049] The resin having a urethane bond and a polymerizable unsaturated bond used in producing the resin component (II) is an oligomer, and may be referred to as "resin (a)." The resin having a siloxane bond and a polymerizable unsaturated bond used in producing the resin component (II) is an oligomer, and in this embodiment may be referred to as "resin (b)." Resin component (II) is a polymer formed by polymerizing resins (a) together at their polymerizable unsaturated bonds. When resin (b) is used, resin component (II) is a polymer formed by polymerizing resins (a) and (b) at their polymerizable unsaturated bonds.

[0050] When resin (b) is used, the resin component (II) preferably has both a urethane bond and a siloxane bond in one molecule.

[0051] The resin (a) is not particularly limited as long as it has a urethane bond and a polymerizable unsaturated bond. Examples of the resin (a) include those having a urethane bond and a (meth)acryloyl group as the group having a polymerizable unsaturated bond, and more specifically, urethane (meth)acrylates and the like. In this specification, the term "(meth)acrylate" is a concept that encompasses both "acrylate" and "methacrylate." The same applies to terms similar to (meth)acrylate; for example, the term "(meth)acryloyl group" is a concept that encompasses both "acryloyl group" and "methacryloyl group."

[0052] The resin (b) is not particularly limited as long as it has a siloxane bond and a polymerizable unsaturated bond. Examples of the resin (b) include various known silicone resins having a (meth)acryloyl group as a group having a polymerizable unsaturated bond, and more specifically, examples thereof include modified polydialkylsiloxanes in which a (meth)acryloyl group is bonded to one or both ends of a polydialkylsiloxane such as polydimethylsiloxane.

[0053] Resin component (II) has high solubility in solvents due to its composition, and therefore the resin composition containing resin component (II) also has high solubility in solvents. Such a highly soluble resin composition can be easily formed into a resin composition layer by, for example, printing it onto an object to be applied using various printing methods. Then, by solidifying the resin composition layer by drying without curing, a layer (resin layer, resin sheet) similar to the resin sheet can be produced. This method is suitable for forming electrodes or wiring using the resin composition containing a conductive component.

[0054] Such a resin composition having high solubility is used to form a resin sheet having stretchability, and a stretchable device constructed using this resin sheet has the great advantage of being able to suppress breakage during stretching. From a materials perspective, possible causes of breakage in conventional stretchable devices during stretching include (i) structural defects such as voids and interfacial peeling caused by shrinkage due to heat or curing reactions, (ii) uneven hardness caused by uneven composition, and (iii) deterioration of materials over time caused by light exposure, oxidation, etc. Therefore, by suppressing structural defects such as voids, interfacial peeling, compositional irregularities, and deterioration of materials over time, it is possible to suppress breakage of stretchable devices when they are stretched. Although stretchable substrates are typically processed by thermal melting or crosslinking by thermal or photo-curing, there are concerns that the reliability of stretchable devices may be reduced when considering microfabrication due to the reasons (i) to (iii) above. In contrast, if there were a resin that could be molded by simply coating and drying the resin composition, compatible with lamination methods, it would be expected to produce good results.

[0055] The stretchable resin substrate 10 is obtained by drying and solidifying the resin composition of the specific example to obtain a stretchable resin substrate in the form of a resin sheet (hereinafter, sometimes referred to as a "resin sheet"). A plurality of resin sheets may be laminated to produce the stretchable resin substrate. The resin sheet contains resin component (II) as a main component and therefore has good stretchability. When resin (b) is used, the resin sheet also has moderate water repellency, which suppresses deterioration over time due to hydrolysis. The resin sheet having such properties is particularly suitable for constructing various stretchable devices, including wearable devices.

[0056] The resin sheet can be formed by simply solidifying the resin composition by drying, as described above, without carrying out a curing reaction of the resin composition, and therefore does not have the drawbacks associated with carrying out a curing reaction.

[0057] For example, it is extremely difficult to uniformly cure a material that is not transparent to ultraviolet light in a photocurable resin sheet. For example, when ultraviolet light is irradiated around a mounted device or electronic component in a photocurable resin sheet, the transmittance of ultraviolet light varies, resulting in areas with different degrees of cure, and the resin sheet is prone to breakage in areas with low crosslink density. Furthermore, non-crosslinked areas are prone to deterioration due to oxidation. On the other hand, the thermosetting reaction tends to cause differential shrinkage in the resin sheet due to heat distribution during curing. Such differential shrinkage can easily cause separation at the interface between different constituent materials, such as between a device and a sealant. Furthermore, if regions with different degrees of cure occur in the resin sheet due to heat distribution, repeated expansion and contraction can easily cause deterioration. Furthermore, in both the photocuring reaction and the thermosetting reaction, it is difficult for the reaction to proceed uniformly within the resin sheet, which causes variations in the composition and degree of cure within the resin sheet, resulting in the cured resin sheet lacking the desired elasticity and strength. Furthermore, since the resin contains a curing agent, it is prone to deterioration over time due to heat and light. In contrast, the resin sheet obtained by solidifying the resin composition of the specific example by drying does not have such a problem.

[0058] The resin sheet can be produced, for example, by applying the resin composition to a desired location and solidifying it by drying, without carrying out a curing reaction.

[0059] The resin composition can be applied by a known method using various coaters or wire bars, or by various printing methods including inkjet printing.

[0060] When producing a resin sheet, the drying temperature of the resin composition is preferably 25 to 150° C., more preferably 25 to 120° C. When the drying temperature is 25° C. or higher, the resin sheet can be produced more efficiently. When the drying temperature is 150° C. or lower, the drying temperature is prevented from becoming excessively high, which makes it less likely that deformation of the release sheet or damage to the resin sheet will occur, and thus prevents deterioration of the resin sheet.

[0061] In producing the resin sheet, the drying time of the resin composition may be appropriately set depending on the drying temperature, but is preferably 10 to 120 minutes, more preferably 30 to 90 minutes. When the drying time is within this range, a resin sheet with good properties can be efficiently produced.

[0062] Completion of solidification (formation of a resin sheet) by drying of the resin composition can be confirmed, for example, by the fact that no clear change in the mass of the resin composition being dried is observed any more.

[0063] The stretchability of the elastic resin substrate can be appropriately set according to the stretchability required for the solar cell module. The stretchability can be increased, for example, by increasing the amount of elastic resin. It can also be adjusted by increasing the mol% of bonds with high stretchability in the resin. For example, the stretchability of the elastic resin substrate can be increased by increasing the proportion of urethane bonds in the resin.

[0064] The thickness of the stretchable resin substrate is not particularly limited, but for example, a thickness of 10 to 5000 μm can be used.

[0065] <Stretchable electrode> The stretchable electrode 30 used in the solar cell modules according to the first to third embodiments contains a stretchable resin and a conductive filler. The elastic resin is not particularly limited, and any known elastic resin can be used, such as epoxy resins, urethane resins, urea resins, polyurethane urea resins, methacrylic acid resins, polyacrylic resins, silicone resins, diene resins, polyester resins, polyether resins, polyamide resins, polystyrene resins, and polyimide resins.

[0066] The conductive filler is not particularly limited, and any known conductive filler can be used. Examples include silver (Ag) powder, carbon (C), copper (Cu) powder, palladium (Pd) powder, gold (Au) powder, and platinum (Pt) powder. Among these, silver is preferred because of its low resistance.

[0067] The resin used for the stretchable electrode 30 is preferably soluble in at least one solvent selected from diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate (BCA), diethylene glycol monoethyl ether acetate, and α-terpineol.

[0068] Among the above resins, urethane-based resins are preferred because they can be solidified without undergoing a curing reaction. Furthermore, urethane-based resins have the best stretchability, making it possible to fabricate stretchable electrodes that are stretchable and conductive.

[0069] The breaking expansion ratio of the stretchable electrode 30 may be appropriately set to the breaking expansion ratio required for the solar cell module. For example, a value of approximately 30 to 300% is typical. However, from the viewpoint of ensuring excellent stretchability of the solar cell module, a value of 50% or more is preferable, 100% or more is more preferable, and 200% or more is even more preferable. Here, the breaking expansion ratio is defined as {(length at break - length before stretching) / length before stretching} × 100. The breaking expansion ratio can be measured in each direction, but in this specification, "breaking expansion ratio of 50% or more" refers to the breaking expansion ratio in the direction in which the breaking expansion ratio is greatest. If the breaking expansion ratio is not anisotropic, the breaking expansion ratio will be equal in all directions. Furthermore, if the anisotropy of the breaking expansion ratio is small, the breaking expansion ratio will be close in all directions. For example, the breaking expansion ratio can be measured as follows. Five strip-shaped measurement samples, each 10 mm wide and 35 mm long, are cut out from the stretchable electrode material. The elongation of each measurement sample is calculated using the method described below, and the average value is taken as the elongation. The metal substrate is clamped between the upper and lower grips of the measuring device, and the measurement sample is fixed to the metal substrate with double-sided tape so that the measurement point is 10 mm wide and 10 mm long. The measurement sample is then pulled at a pulling rate of 10 mm / min using a tensile tester (e.g., Autograph AGS-5kNX, manufactured by Shimadzu Corporation). The length of the measurement sample at the time of breakage is measured, and the length (10 mm) before pulling is subtracted from the measured length to calculate the elongation. When the resin constituting the stretchable electrode 30 is the same as the resin constituting the stretchable resin substrate, the stretchable electrode 30 has a smaller elongation rate than the stretchable resin substrate because it contains a conductive filler. Therefore, the breaking elongation rate of the stretchable electrode 30 is the upper limit of the elongation rate as a solar cell module.

[0070] When producing a stretchable electrode pattern, a stretchable electrode paste is produced by adding a conductive filler as a conductive component to the resin composition exemplified above. The stretchable electrode paste is then applied to a stretchable resin substrate. The solvent is then removed and the resulting paste is dried and solidified to produce a stretchable electrode pattern. When the resin component (II) described above is used, solidification can be achieved without a curing reaction.

[0071] The thickness of the stretchable electrode is not particularly limited, but can be, for example, 3 to 50 μm.

[0072] <Solar cell) Although it is not excluded that the solar cells constituting the solar cell module of the present invention themselves have elasticity, solar cells with no elasticity at all or solar cells with low elasticity (elongation rate of 1% or less) are envisioned. Examples of solar cells with no stretchability include inorganic solar cells such as silicon solar cells and compound semiconductor solar cells. Most organic solar cells have an elongation rate of 1% or less, but some organic solar cells may have an elongation rate of more than 1%, depending on the material. This elongation rate of 1% or less means that 10 samples of the target solar cell are subjected to a 1000-cycle test using a tensile testing machine (for example, an Autograph (manufactured by Shimadzu Corporation)) set to an elongation rate of 1%, and none of them break and the decrease in power generation is 5% or less.

[0073] The solar cells used in the solar cell modules according to the first to third embodiments are not particularly limited except for the elongation rate of 1% or less, and known solar cells can be used.

[0074] For example, in terms of electrode arrangement, either (a) a double-sided electrode solar cell or (b) a back-side electrode solar cell as shown in FIG. 6 can be used.

[0075] The solar cell shown in FIG. 6(a) is a double-sided electrode solar cell in which an n-type side electrode 26a (or a p-type side electrode) is arranged on one main surface and a p-type side electrode 25a (or an n-type side electrode) is arranged on the other main surface. In the double-sided electrode solar cell shown in FIG. 6(a), for example, a stacked structure of an n-type semiconductor layer 23a and a p-type semiconductor layer 22a is arranged so that the n-type semiconductor layer 23a is located on the light-receiving surface side to form a pn junction, and an n-type side electrode 26a is provided on the light-receiving surface side of the n-type semiconductor layer 23a, and a p-type side electrode 25a is provided on the back surface side of the p-type semiconductor layer 22a.

[0076] The solar cell shown in FIG. 6(b) is a back contact solar cell in which an n-type electrode 26b and a p-type electrode 25b, which are electrically separated from each other, are arranged on one main surface. 6(b), an n+ diffusion layer 23b and a p+ diffusion layer 22b are formed on the surface opposite the light-receiving surface, with an n-type electrode 26b and a p-type electrode 25b formed thereon, respectively. In a back contact solar cell, the electrodes can be concentrated on the back surface, eliminating the need for an electrode on the light-receiving surface, which makes it possible to increase the light-receiving surface and capture more light, thereby improving conversion efficiency.

[0077] Whether a double-sided electrode solar cell or a back-side electrode solar cell is used, it is preferable to use a solar cell in which the electrodes (or wiring) connected to the p-type electrodes 25a, 25b and the n-type electrodes 26a, 26b are arranged on the back side of the solar cell, because the stretchable electrode pattern can be formed according to the electrode pattern to be arranged on the back side of the solar cell.

[0078] Furthermore, as mentioned above, even if solar cells are classified into three types, silicon-based, compound semiconductor-based, and organic-based, there are no particular restrictions other than an elongation rate of 1% or less, and any type of solar cell can be used.

[0079] In the solar cell module according to the present invention, the area ratio of the solar cells (cell area ratio) is preferably 80% or less from the viewpoint of preventing breakage.

[0080] <Stretchable conductive adhesive> FIG. 7 is an exploded cross-sectional view showing a solar cell, a stretchable conductive adhesive, a stretchable resin substrate, and a stretchable electrode. 7, it is preferable to bond the solar cell 20 and the stretchable electrode 30 using a stretchable conductive adhesive 40. The stretchable conductive adhesive 40 can be solidified by drying. A specific bonding method is, for example, to apply an elastic conductive adhesive 40 to each position of the elastic electrode pattern 30 using a known method such as screen printing, and then to install the back electrode type solar cell 20 by arranging the electrode patterns 25, 26 on the back electrode type solar cell 20 side on the elastic conductive adhesive 40 that has been applied in the same pattern as the elastic electrode pattern 30, and then to remove the solvent in the elastic conductive adhesive 40 and dry and solidify it.

[0081] The elastic conductive adhesive 40 contains an elastic resin and an electrically conductive filler. The elastic resin is not particularly limited, and any known elastic resin can be used, such as epoxy resins, urethane resins, urea resins, polyurethane urea resins, methacrylic acid resins, polyacrylic resins, silicone resins, diene resins, polyester resins, polyether resins, polyamide resins, polystyrene resins, and polyimide resins.

[0082] The conductive filler is not particularly limited, and any known conductive filler can be used. Examples include silver (Ag) powder, carbon (C), copper (Cu) powder, palladium (Pd) powder, gold (Au) powder, and platinum (Pt) powder. Among these, silver powder is preferred because it has low resistance and is less susceptible to oxidation.

[0083] It is preferable that the resin used in the stretchable conductive adhesive 40 is soluble in one or more solvents selected from methyl ethyl ketone (MEK), methyl isobutyl ketone, butyl acetate, propylene glycol monomethyl ether acetate (PGMEA), and diethylene glycol monomethyl ether acetate (BCA).

[0084] The breaking expansion rate of the stretchable conductive adhesive 40 may be set appropriately depending on the expansion rate required for the solar cell module, and is generally about 3 to 1000%, for example, but from the viewpoint of the solar cell module exhibiting excellent expansion and contraction, it is preferably 50% or more, more preferably 70% or more, and even more preferably 100% or more. The breaking expansion rate of the stretchable conductive adhesive 40 is defined in the same way as the breaking expansion rate of the stretchable electrode 30, and the measurement method is also the same. In addition, when the resin that constitutes the stretchable conductive adhesive 40 is the same as the resin that constitutes the stretchable electrode 30, the breaking expansion rate of the stretchable conductive adhesive 40 will be approximately the same as the breaking expansion rate of the stretchable electrode 30.

[0085] Of the above resins, urethane resins that can be solidified without undergoing a curing reaction are preferred.

[0086] The thickness of the stretchable conductive adhesive is not particularly limited, but can be, for example, 10 to 1500 μm.

[0087] <Action and effect> The effects of the solar cell module according to the present invention will be described with reference to FIGS. 8(a) and 8(b).

[0088] As shown in Figure 8(b), when a substrate that is not thin enough is bent, only the center of the substrate is free from stress, but when bent, compressive stress acts on the inside of the substrate and tensile stress acts on the outside. In other words, contracting stress acts on the inside of the substrate and stretching stress acts on the outside.

[0089] FIG. 8(a) is a diagram schematically illustrating a solar cell module 100A according to the present invention. The direction and length of the double-headed arrows in the diagram conceptually indicate the direction and magnitude of the tensile stress in the vicinity. Also, reference numeral 10A indicates an elastic resin substrate, and reference numeral 20A indicates a "non-elastic solar cell." Solar cell cells of various sizes are arranged. Stretchable electrodes and stretchable conductive adhesives are not shown in the diagram.

[0090] 8(a), the only stretched portions of the elastic resin substrate 10A are those portions to which the solar cells 20A are not bonded. The elastic resin substrate 10A in the portions to which the solar cells 20A are bonded does not stretch. This point will be conceptually explained using FIG.

[0091] In FIG. 9, the stretchable electrodes and the stretchable conductive adhesive are omitted from the illustration. When the stretchable resin substrate 10A is divided into three portions 10Aa, 10Ab, and 10Ac when viewed from the direction in which the stretchable resin substrate 10A, stretchable electrode 30AA, stretchable conductive adhesive 40A, and solar cell 20A are layered, portions 10Aa and 10Ac are stretchable because they do not have a non-stretchable solar cell 20A bonded thereto. In contrast, portion 10Ab is bonded to a non-stretchable solar cell 20A, so its stretching is suppressed. Here, because the stretchable electrode 30AA and stretchable conductive adhesive 40A are disposed between portion 10A and solar cell 20A, peeling between portion 10Ab, which attempts to stretch, and the non-stretchable solar cell 20A is suppressed.

[0092] In this way, in the solar cell module of the present invention, the individual solar cells are bonded to the stretchable resin substrate via a stretchable electrode, or a stretchable electrode and a stretchable conductive adhesive, so that the portions to which the individual solar cells are not bonded can stretch, thereby making the solar cell module stretchable.

[0093] As shown in FIG. 8, the solar cell modules may include solar cells with different sizes and characteristics.

[0094] <Sealing layer> FIG. 10 shows a schematic cross-sectional view of a portion of a solar cell module according to the present invention, in which sealing layers 50 are provided on the top and bottom surfaces of solar cells 20. In FIG.

[0095] The resin used for the sealing layer 50 is preferably a resin having elasticity. There are no particular limitations on the elastic resin, and known resins can be used. Examples include epoxy resins, urethane resins, urea resins, polyurethane urea resins, methacrylic acid resins, polyacrylic resins, silicone resins, diene resins, polyester resins, polyether resins, polyamide resins, polystyrene resins, and polyimide resins.

[0096] The resin used for the sealing layer 50 is preferably soluble in one or more solvents selected from N,N-dimethylacetamide (DMAc), methyl ethyl ketone (MEK), N,N-dimethylformamide (DMF), diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate (BCA), diethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, acetone, ethanol, methanol, ethyl lactate, butyl lactate, toluene, isopropyl alcohol, isobutyl alcohol, ethyl acetate, and butyl acetate.

[0097] In the example shown in FIG. 10, the sealing layer 50 is provided on both the top and bottom surfaces of the solar cell 20, but it may be provided on only one of the top and bottom surfaces.

[0098] The sealing layer 50 can be formed by a known method.

[0099] (Solar cell module manufacturing method) FIG. 11 shows an example of a method for manufacturing a solar cell module according to the present invention. The solar cell module of the present invention can be manufactured through the steps of (a) preparing a predetermined number of solar cells, (b) forming an elastic electrode pattern on an elastic resin substrate, (c) applying an elastic conductive adhesive paste onto the elastic electrode pattern, (d) arranging solar cells on the elastic conductive adhesive paste, and (e) drying and solidifying the elastic conductive adhesive paste to fix the solar cells. [Example]

[0100] Below, specific numerical examples of the expansion rate of the solar cell module, the breaking expansion rate of the expandable electrode, the output voltage, and the amount of power generated per unit area for the solar cell module according to the present invention were examined.

[0101] [Example 1] Example 1 is a solar cell module including two solar cells. (Example of manufacturing a stretchable resin substrate) <Examples of raw materials for resin compositions> The raw materials that can be used to produce the resin composition are listed below. Resin (a) (a)-1: Urethane acrylate oligomer (product name: UN-5500, manufactured by Negami Chemical Industrial Co., Ltd.) ·Resin (b) (b)-1: Methacrylate-modified polydimethylsiloxane in which one end is modified with a methacryloyl group (product name: Silaplane (registered trademark) FM-0721, manufactured by JNC Corporation) Polymerization initiator (c) (c)-1: Dimethyl 2,2'-azobis(2-methylpropionate), azo polymerization initiator (product name: V601, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) RAFT agents (1)-1: RAFT agent represented by the following formula (1)-1 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (3)-1: RAFT agent represented by the following formula (3)-1 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Other polymerizable components MMA: methyl methacrylate ·solvent BCA: butyl carbitol acetate

[0102] [ka]

[0103] <Production Example of Resin Composition> Resin (a)-1 (100 parts by mass), polymerization initiator (c)-1 (0.8 parts by mass), RAFT agent (1)-1 (0.245 parts by mass), and BCA are weighed into a flask and mixed at room temperature using a stirrer to obtain a raw material mixture. The blending amounts of resin (b), polymerization initiator (c), and RAFT agent are determined based on 100 parts by mass of resin (a). Furthermore, BCA, which is a solvent, is mixed in such that 100 parts by mass of resin (a) becomes 15% by mass of the raw material mixture.

[0104] The sealed flask is then evacuated to remove air. Next, the raw material mixture is dissolved in an oil bath under a nitrogen atmosphere, and the temperature is raised while continuing to stir, and a polymerization reaction is carried out at 90°C for 20 minutes to produce resin component (II) and a resin composition containing this resin component (II).

[0105] <Example of resin sheet (elastic resin substrate) production> Using a spray coater, the resin composition obtained above is applied onto a release film and dried at 115°C for 60 minutes to produce a resin sheet (test resin sheet, thickness 80 μm) without undergoing a curing reaction, which is used as an elastic resin substrate.

[0106] (Example of manufacturing stretchable electrode paste) The raw materials for the stretchable electrode paste are the same as those for the resin composition prepared when producing the stretchable resin substrate, except that silver powder with a particle size of 0.5 μm to 5.0 μm is added and the amount of resin is adjusted.

[0107] (Example of making elastic conductive adhesive paste) The raw materials for the stretchable conductive adhesive paste are the same as those for the stretchable electrode paste, except that silver powder with a particle size of 0.5 μm to 5.0 μm is added and the amount of resin is adjusted.

[0108] (Example of solar cell preparation) The solar cells used have dimensions (Lx, Ly) of 1.5 mm and 5.75 mm in the x and y directions, respectively, and as shown in Figure 12, two solar cells are placed side by side in the x direction with their longitudinal directions parallel to each other. As the solar cell, for example, the BCS series manufactured by TDK Corporation can be used.

[0109] (Example of solar cell module production) The stretchable electrode paste is applied in a predetermined pattern onto a 100 mm x 100 mm stretchable resin substrate, and then dried and solidified to form a stretchable electrode pattern. Next, a stretchable conductive adhesive paste is applied onto the stretchable electrode pattern. Next, each solar cell is placed on the stretchable conductive adhesive paste that has been applied in a predetermined pattern so that the first conductivity type electrode and the second conductivity type electrode of each of the two solar cells are positioned. Thereafter, the solvent in the stretchable conductive adhesive paste is removed, the paste is dried and solidified, and the solar cell is fixed to produce a solar cell module comprising two solar cell units.

[0110] (Examples of numerical values ​​for the expansion rate of a solar cell module, the breaking expansion rate of an elastic electrode, output voltage, and power generation per unit area) Table 1 shows examples of specific numerical values ​​for the breaking expansion rate of the stretchable electrode, the expansion rate of the solar cell module, the output voltage, and the amount of power generated per unit area.

[0111] The length of the stretchable resin substrate in both the x and y directions is 100 mm. The portion of the stretchable resin substrate where the solar cell is bonded via the stretchable electrode and stretchable conductive adhesive (hereinafter sometimes referred to as the "bonded portion") does not substantially stretch, and only the portion where the solar cell is not bonded (hereinafter sometimes referred to as the "non-bonded portion") stretches. The stretching ratio of the entire solar cell module when the stretchable electrode breaks can be estimated using the stretching ratio at break of the stretchable electrode as follows: Stretch rate (%) = {(stretched length - length before stretching) (mm) / length before stretching (mm)} x 100 (%), Length when stretched (mm) = (length of part other than cell (electrode) × breaking stretch rate of stretchable electrode + length of entire cell part) (mm), The length before expansion (mm) = 100 mm, so Stretching rate (%) = [(length of the part other than the cell (electrode) × stretchability at break of the stretchable electrode + length of the entire cell part) - 100} mm / 100 mm] × 100 (%) = {(length of the part other than the cell (electrode) × breaking stretch rate of the stretchable electrode + length of the entire cell part) - 100} (%)

[0112] Let SSx and SSy be the breaking elongation rates [%] of the stretchable electrode in the x and y directions, respectively, Lx and Ly be the dimensions of the solar cell in the x and y directions, respectively, and Nx and Ny be the numbers of solar cell cells in the x and y directions, respectively. Then, let TSx and TSy be the elongation rates of the solar cell module in the x and y directions; Tsx〔%〕=〔(100-Lx×Nx)×{(100(%)+SSx(%)) / 100(%)} +Lx×Nx〕-100 ···(1) Tsy〔%〕=〔(100-Ly×Ny)×{(100(%)+SSy(%)) / 100(%)} +Ly×Ny〕-100 ···(2) In the numerator of the second term in equations (1) and (2), the first term indicates the length of the "non-junction" part, and the second term indicates the length of the "junction" part (same as the total length of the solar cell).

[0113] If the output voltage of a solar cell module is 0.65V per cell, then it is calculated as 0.65V x number of solar cell cells (Nx x Ny).

[0114] The power generation per solar cell under light irradiation of 200 lux is 0.1 μW / mm 2 Then, Power generation amount P=0.1μW / mm 2 × Light receiving area of ​​one solar cell [mm 2 〕, The light-receiving area is the area effective for power generation, excluding areas that do not generate power, such as the sealing material, from the cell area.

[0115] [Table 1]

[0116] [Example 2] Example 2 is an example in which a solar cell module was fabricated in the same manner as Example 1, except that the solar cell module had 16 solar cells, each solar cell had a size of Lx = 5 mm and Ly = 5 mm, and the solar cells were arranged in rows of four in each of the x and y directions.

[0117] [Example 3] Example 3 is an example in which a solar cell module was fabricated in the same manner as Example 1, except that the solar cell module had 42 solar cells, each having a size of Lx=5 mm and Ly=5 mm, and the solar cells were arranged in a row of 6 in the x direction and 7 in the y direction.

[0118] [Example 4] Example 4 is an example in which a solar cell module was fabricated in the same manner as Example 1, except that the solar cell module had 25 solar cells, each having a size of Lx=10 mm and Ly=10 mm, and the solar cells were arranged in rows of five in each of the x and y directions.

[0119] [Example 5] Example 5 is an example in which a solar cell module was fabricated in the same manner as Example 1, except that the solar cell module had 49 solar cells, each having a size of Lx=10 mm and Ly=10 mm, and the solar cells were arranged in rows of 7 in each of the x and y directions.

[0120] [Example 6] Example 6 is an example in which a solar cell module was fabricated in the same manner as Example 1, except that the solar cell module had 900 solar cells and the solar cells were arranged in a row of 60 in the x direction and 15 in the y direction.

[0121] [Example 7] Example 7 is an example in which a solar cell module was fabricated in the same manner as Example 1, except that the solar cell module had 25 solar cells, each having a size of Lx=45 mm and Ly=45 mm, and the solar cells were arranged two by two in each of the x and y directions.

[0122] Based on Examples 6 and 7, when the stretchable electrode has a breaking stretch rate of 50% or more, the elongation rate of the solar cell module can be made 5% or more. Based on Examples 2 to 7, if the stretchable electrode has a breaking stretch rate of 50%, the elongation rate of the solar cell module can be set to 5% to 40%. Based on Examples 3 to 7, when the stretchable electrode has a breaking stretch rate of 50%, the elongation rate of the solar cell module is 5% or more and the power generation amount per unit area is 50 μW / mm 2 It can be more than that. Based on Examples 3 to 7, if the stretchable electrode has a breaking stretch rate of 50%, and the cell area ratio is 10% or more, the elongation rate of the solar cell module is 5% or more, and the power generation amount per unit area is 50 μW / mm 2 It can be more than that.

[0123] The larger the area occupied by the solar cell (cell area ratio), the higher the amount of power generated per unit area, but the lower the expansion / contraction ratio. In the solar cell module of the present invention, there is a trade-off between the amount of power generated and the expansion / contraction ratio.

[0124] Even if the cell area ratio of a solar cell module is the same, if the solar cell module is made up of smaller solar cells, the density of bending parts will be higher than if it is made up of larger solar cells, and therefore it can respond to finer expansion and contraction. The densities of the bends in the x and y directions in Examples 1 to 7 are as follows:

[0125] [Table 2] [Explanation of symbols]

[0126] 10, 10A stretchable resin base material 20, 20A, 21 solar cells 25 First conductive electrode 26 Second conductive electrode 30, 30AA stretchable electrode 40, 40A Elastic Conductive Adhesive 50 Sealing layer 100, 200, 300, 100A solar module

Claims

1. an elastic resin substrate; A plurality of solar cells having an elongation rate of 1% or less are provided on the elastic resin substrate, and an elastic electrode is formed in a pattern to electrically connect the plurality of solar cells, the first and second conductive electrodes of the solar cell are joined to the stretchable electrode by a stretchable conductive adhesive, The solar cell module, wherein the stretchable electrode and the stretchable conductive adhesive contain the same resin component as the resin component constituting the stretchable resin substrate, and a conductive filler.

2. A solar cell module as described in claim 1, wherein the resin used in the stretchable electrode is soluble in one or more solvents selected from diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate (BCA), diethylene glycol monoethyl ether acetate, and α-terpineol, and the resin used in the stretchable conductive adhesive is soluble in one or more solvents selected from methyl ethyl ketone (MEK), methyl isobutyl ketone, butyl acetate, propylene glycol monomethyl ether acetate (PGMEA), and diethylene glycol monomethyl ether acetate (BCA).

3. A solar cell module described in either claim 1 or 2, wherein the resin component contains a polymer of a resin (a) having a urethane bond and a polymerizable unsaturated bond and a resin (b) having a siloxane bond and a polymerizable unsaturated bond.

4. A solar cell module described in any one of claims 1 to 3, wherein the stretchable resin substrate, the stretchable electrode, and the stretchable conductive adhesive are all solidified by drying.

5. The solar cell module according to any one of claims 1 to 4, wherein the expansion / contraction rate is 5% or more.

6. The solar cell module according to any one of claims 1 to 5, wherein the density of bends is 0.05 / mm or more.

7. The solar cell module according to any one of claims 1 to 6, wherein the stretchable electrode has a breaking stretch rate of 50% or more.

8. 8. The solar cell module according to claim 1, wherein the area occupied by the plurality of solar cells is 10% or more of the total area of ​​the solar cell module.

9. The solar cell module according to any one of claims 1 to 8, further comprising a sealing layer on at least one of the upper and lower surfaces of the solar cell.

10. an elastic resin substrate; A solar cell having an elongation rate of 1% or less is provided on the stretchable resin substrate, and a stretchable electrode connected to the solar cell is provided, the first and second conductive electrodes of the solar cell are joined to the stretchable electrode by a stretchable conductive adhesive, The solar cell module, wherein the stretchable electrode and the stretchable conductive adhesive contain the same resin component as the resin component constituting the stretchable resin substrate, and a conductive filler.

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