JP6877897B2 - Solar cell module - Google Patents

Description

It relates to a solar cell module using a single-sided electrode type cell.

In recent years, as interest in global environmental issues has increased, new energy technologies that utilize natural energy have received a great deal of attention. As one of them, there is a great deal of interest in systems that use solar energy, and in particular, photovoltaic power generation, which converts light energy into electrical energy by utilizing the photoelectric conversion effect, is widely used as a means of obtaining clean energy.

There are various types of solar cell elements, such as those using compound semiconductors and those using organic materials, but solar cells using silicon crystals are the mainstream.

Currently, most solar cells manufactured and sold have n electrodes formed on the surface (light receiving surface) on which sunlight is incident, and p electrodes on the surface (back surface) opposite to the light receiving surface. It is a double-sided electrode type solar cell having a formed structure. Further, the development of a back electrode type solar cell in which no electrode is formed on the light receiving surface of the solar cell and the n electrode and the p electrode are formed only on the back surface of the solar cell is being promoted.

For example, Patent Document 1 discloses a back electrode type solar cell with a wiring sheet.
Patent Document 1 includes a wiring sheet in which the back electrode type solar cell and the wiring sheet are adhered to each other by using a fixing resin installed between the electrodes of the back electrode type solar cell and at least one of the wirings of the wiring sheet. A back electrode type solar cell is disclosed.

Japanese Unexamined Patent Publication No. 2012-99569

However, in the back electrode type solar cell with a wiring sheet described in Patent Document 1, light incident from the back surface is not taken into consideration.

In order to further improve the power generation efficiency, the present invention provides a solar cell module using a single-sided electrode type solar cell in consideration of light intake not only from the surface on which the electrode is not formed but also from the surface on which the electrode is formed. The purpose is to provide.

The solar cell module of the present invention includes a plurality of solar cells having a first electrode and a second electrode having a polarity different from that of the first electrode on one surface, a first electrode of the first solar cell, and a first electrode. The solar cell is provided with a plurality of wires for electrically connecting the second electrode of the second solar cell adjacent to the solar cell of the above, and both the first electrode and the second electrode are arranged in the solar cell. It is characterized by having a non-region on one side and having a solar cell string in which a plurality of solar cells are connected in series by wiring.

According to the present invention, it is possible to provide a solar cell module using a single-sided electrode type solar cell capable of taking in light from a surface on which an electrode is formed.

It is a top view which looked at the solar cell which concerns on 1st Embodiment of this invention from the electrode formation surface side. It is sectional drawing of the solar cell which concerns on 1st Embodiment of this invention. FIG. 5 is a plan view of a part of the solar cell module according to the first embodiment of the present invention as viewed from the electrode forming surface side. FIG. 5 is a plan view of a part of the solar cell module according to the first embodiment of the present invention as viewed from the electrode forming surface side. It is sectional drawing of BB'of FIG. 4 which concerns on 1st Embodiment of this invention. FIG. 5 is a plan view of a part of the solar cell module according to the first embodiment of the present invention as viewed from the electrode forming surface side. It is a top view which looked at the solar cell which concerns on 1st Embodiment of this invention from the electrode formation surface side. It is sectional drawing of the solar cell module which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the manufacturing process of the solar cell string which concerns on 2nd Embodiment of this invention. It is sectional drawing of the solar cell module which concerns on 2nd Embodiment of this invention. It is a top view which looked at the solar cell which concerns on 3rd Embodiment of this invention from the electrode formation surface side. It is a top view which looked at the solar cell which concerns on 4th Embodiment of this invention from the electrode formation surface side. It is sectional drawing of the solar cell module which concerns on 5th Embodiment of this invention. It is sectional drawing of the solar cell module which concerns on 6th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.

[Embodiment 1]
A solar cell module using a single-sided electrode type solar cell according to the first embodiment will be described with reference to the drawings.
(Solar cell)
FIG. 1 is a plan view of the single-sided electrode type solar cell used in the present embodiment as viewed from the electrode forming surface side. As shown in FIG. 1, a plurality of n-type electrodes 26 and p-type electrodes 27 are arranged at predetermined intervals, and each has a long rectangular shape. The n-type electrode 26 and the p-type electrode 27 are alternately arranged one by one at a predetermined interval in a direction orthogonal to the longitudinal direction. The width and pitch of the n-type electrode 26 and the p-type electrode 27 are substantially constant. The width of the electrode indicates a direction orthogonal to the longitudinal direction of the electrode, that is, a length in the lateral direction. The electrode pitch indicates the distance between the midpoint of the electrode in the lateral direction and the midpoint of the adjacent electrode in the lateral direction.

FIG. 2 is a diagram showing a cross section of the single-sided electrode type solar cell in FIG. 1A'A'. In the single-sided electrode type solar cell 2, the antireflection film 22 is formed on the surface side of the silicon substrate 21 having an uneven shape, and the passivation film 25 is formed on the electrode forming surface side of the silicon substrate 21. As the silicon substrate 21, for example, a substrate made of polycrystalline silicon or single crystal silicon having either an n-type or p-type conductive type can be used. The thickness of the silicon substrate 21 is preferably about 50 μm or more and 400 μm or less. A film made of silicon nitride was used as the antireflection film 22, and a film made of silicon oxide was used as the passivation film 25. Neither is limited to these. As the passivation film 25, for example, a silicon nitride film, silicon oxide, aluminum oxide, or a laminate thereof can be used.

Further, on the electrode forming surface side inside the silicon substrate 21, an n-type impurity diffusion region 23 in which n-type impurities such as phosphorus are diffused and a p-type impurity diffusion region 24 in which p-type impurities such as boron are diffused are formed. It is formed. The n-type impurity diffusion region 23 is a region containing n-type impurities such as phosphorus. The p-type impurity diffusion region 24 is a region containing p-type impurities such as boron and aluminum.

Inside the silicon substrate 21 having an n-type or p-type conductive type, a plurality of pn junctions are formed at the interface between the n-type impurity diffusion region 23 or the p-type impurity diffusion region 24 and the silicon substrate 21. Each of the n-type electrode 26 connected to the n-type impurity diffusion region 23 and the p-type electrode 27 connected to the p-type impurity diffusion region 24 via a contact hole provided in the passivation film 25 is a silicon substrate. It is an electrode corresponding to each of a plurality of pn junctions formed inside the 21. As the n-type electrode 26 and the p-type electrode 27, for example, metals such as Ag, Ti / Pd / Ag, Ti / W / Cu, and Ni / Cu can be used.
(Wiring between solar cells)
FIG. 3 is a plan view of a part of the solar cell module according to the present embodiment as viewed from the electrode forming surface side. As shown in FIG. 3, the wiring 41 is the n-type electrode 26 (first electrode) of one solar cell and the p-type electrode 27 (second electrode) of the other solar cell among the adjacent solar cells. Connect with the electrode). The n-type electrode 26 and the p-type electrode 27 are connected to the wiring 41 at the first wiring connection portion and the second wiring connection portion, respectively. The wiring 41 is arranged from the center of the n-type electrode 26 to the center of the p-type electrode 27 of the adjacent solar cell. The wiring 41 is arranged along the long n-type electrode 26 and the long p-type electrode 27 of the adjacent solar cell. The length of the wiring 41 is not particularly specified, but it is preferably a length that does not cause resistance loss when a current is collected. For example, as shown in FIG. 4, the wiring 41 extends from one end of the n-type electrode 26 (around one end) to the other end (around the other end) of the p-type electrode 27 of the adjacent solar cell. It can be about the same length as the length. Most of the current generated inside the solar cell flows toward the electrode directly below, and further flows toward the wiring directly below. Therefore, by arranging the wiring 41 from one end to the other end of the n-type electrode 26 and the p-type electrode 27 to which the wiring 41 is connected, the current collected from the solar cell can be passed through the wiring 41. It is not necessary to reduce the resistance of the n-type electrode 26 and the p-type electrode 27 in the longitudinal direction of the wiring 41, and the thickness thereof can be reduced.

Since the n-type electrode 26 and the p-type electrode 27 use an expensive material such as silver, it is desirable to form the n-type electrode 26 and the p-type electrode 27 as thin as possible from the viewpoint of suppressing the manufacturing cost.

Each solar cell has a plurality of n-type electrodes 26 (first electrode) and p-type electrodes 27 (second electrode). The n-type electrode 26 and the p-type electrode 27 of the adjacent solar cell are connected by a wiring 41, respectively, and the wiring 41 and the n-type electrode 26 and the p-type electrode 27 connected to the wiring 41 are connected to each other. Adjacent solar cells are connected in series by providing a plurality of sets consisting of. The wiring connection portion (first wiring connection portion) of the n-type electrode 26, the wiring connection portion (second wiring connection portion) of the p-type electrode 27, and the wiring 41 are arranged in a straight line. Among the adjacent solar cells, the n-type electrode 26 of one solar cell and the p-type electrode 27 of the other solar cell are linearly arranged, and the linear wiring 41 is connected thereto. This facilitates wiring between the solar cells.

The solar cell has a region on the electrode forming side where neither the n-type electrode 26 (first electrode) nor the p-type electrode 27 (second electrode) is arranged. This region is arranged between the wiring 41 connected to the adjacent n-type electrode 26 and the p-type electrode 27, and is arranged at least in the central portion between the wirings 41. By providing a region in which none of the n-type electrode 26 (first electrode), the p-type electrode 27 (second electrode), and the wiring 41 is arranged, sunlight is sent to the solar cell from the electrode forming surface side. It can be incident.

The take-out wirings 41a and 41b are connected to the solar cells at both ends, and a plurality of solar cells are connected in series by the wirings 41 to form a solar cell string 32.

FIG. 5 is a diagram showing a part of the solar cell and the wiring of the BB'cross section of FIG.

As shown in FIG. 5, the wiring 41 is connected to the n-type electrode 26 and the p-type electrode 27. As the wiring 41, for example, a copper wire having a diameter of 120 μm and a circular cross section can be used. The cross-sectional shape of the wiring 41 is not limited to a circular shape, and a rectangular shape or another shape may be used. Since such a wiring 41 can have a large length in the vertical direction (direction perpendicular to the surface direction of the solar cell 2 (Y direction in FIG. 5)), the resistance value of the current collected from the solar cell 2 In consideration of the above, the width of the wiring 41 in the lateral direction (direction parallel to the surface direction of the solar cell 2 (X direction in FIG. 5)) can be reduced. Therefore, more solar SL can be incident on the solar cell 2 from the electrode forming surface side of the solar cell 2, and the power generation area of the solar cell 2 can be expanded.

Since a copper wire generally distributed on the market can be used as the wiring 41, the solar cell module can be manufactured at a very low cost.

For example, the electrodes 26 and 27 and the wiring 41 are heated by using a printed electrode using silver paste as the n-type electrode 26 and the p-type electrode 27 and using a solder-coated copper wiring as the wiring 41. Can be solder-connected. Here, since the silver electrodes 26 and 27 only need to have a function of extracting the current generated from the solar cell 2 and transmitting the current to the copper wiring 41, a thin thickness of about several μm is sufficient and used for the silver electrodes 26 and 27. The amount of silver produced can be reduced and the manufacturing cost can be suppressed. In addition to metal bonding represented by solder, conductive adhesive, ACF (Anisotropic Conductive Film), and ACP (Anisotropic Conductive Paste) are used to connect the n-type electrode 26 and p-type electrode 27 to the wiring 41. Connection is also possible.

Further, it is desirable that the width (length in the X direction) of the n-type electrode 26 and the p-type electrode 27 is smaller than the width (length in the X direction) of the wiring 41. In the present embodiment, the widths of the n-type electrode 26 and the p-type electrode 27 are set to 100 μm. This size is smaller than the width (diameter) of the wiring 41 of 120 μm. With this configuration, the solar SL incident from the electrode forming surface side of the solar cell 2 can be increased to expand the power generation region, and the amount of electrode material used can be suppressed.

The solar cell has a region in which none of the first electrode, the second electrode, and the wiring of the solar cell is arranged in a plan view from the electrode forming surface side. The area of this region is preferably 50% or more of the flat area of the solar cell. With this configuration, it is possible to increase the amount of sunlight SL incident from the electrode forming surface side of the solar cell 2 and further expand the power generation area.

FIG. 6 shows a plan view of a part of the solar cell module according to the present embodiment as viewed from the electrode forming surface side. In the present embodiment, two solar cell strings 32 in which four solar cell 2s are connected in series are arranged side by side. The take-out wiring 41a and the take-out wiring 41c protruding from one end of the solar cell string 32 are connected to each other by a bus bar 62, and the two solar cell strings 32 are connected in series. Further, a plurality of take-out wirings 41b and 41d protruding from the other end of the solar cell string 32 are connected by bus bars 61 and 63, respectively, and have a structure in which the output of the solar cell is taken out to the outside via the bus bars 61 and 63. The solar cell string structure 64 of the above is configured.

FIG. 7 is a view of the solar cell as viewed from the electrode forming surface side. The electrodes 26 and 27 are arranged so that the positions of the n-type electrode 26 and the p-type electrode 27 are interchanged like the solar cell 2'when the solar cell 2 is rotated by 180 ° in the substrate surface. Is preferable. By arranging the electrodes of all the solar cells in this way, if the solar cells connected in series are inverted by 180 ° every other one and installed, the metal wire such as the copper wire which is the wiring 41 can be straightened. Can be connected to the electrodes 26 and 27. As a result, not only the production efficiency is increased, but also the stress load on the wiring 41 is reduced, so that the reliability of the wiring between the solar cells is improved.

Here, "the positions of the n-type electrode 26 and the p-type electrode 27 are interchanged" means that when the solar cell 2 is rotated by 180 ° in the substrate surface, the n-type electrode 26 and the p-type electrode 27 are interchanged. It is not intended that the positions of 27 are exactly the same, as long as at least half of the electrode placement positions overlap.

When the n-type electrode 26 and the p-type electrode 27 are alternately arranged in one direction in the substrate surface of the solar cell 2, the solar cell 2 is rotated by 180 ° in the substrate surface. As a result, the arrangement positions of the n-type electrode 26 and the p-type electrode 27 in at least one direction may be exchanged.
(Solar cell module)
The manufacturing method of the solar cell module of this embodiment is shown below.

It is arranged so as to be a translucent base material, a sealing resin, a solar cell string structure, a sealing resin, and a protective material on the back surface side from the light receiving surface side, and is sealed by heating and pressurizing. Heating is performed, for example, at 160 ° C. Glass is used as the translucent base material. Further, EVA (ethylene vinyl acetate resin) is used as the sealing resin. As the sealing resin, an olefin-based resin may be used. As the back surface side protective material, a film such as PET is used.

The solar cell string structure has a p-type take-out wiring (bus bar 61) and an n-type take-out wiring (bus bar 63), which are electrically connected to the terminal box and output to the outside of the solar cell module. It is electrically connected to the output take-out cable for taking out the.

The solar cell module is manufactured by the above steps. Further, a structure may be formed in which a frame is fitted to the side portion of the sealed solar cell module to obtain high strength.

FIG. 8 shows a schematic cross-sectional view of the solar cell module according to the present embodiment. The solar cell string structure 64 is arranged between the translucent base material 81 and the back surface protective material 82, and the sealing resin 83 is used between the translucent base material 81 and the back surface protective material 82. It is sealed. The sealing resin 83 has a translucent property, and the back surface protective material 82 has a property of reflecting light. A sealing resin 83 is interposed between the solar cell string structure 64 and the back surface side protective material 82, and the sunlight SL reflected by the back surface side protective material 82 is on the non-light receiving surface side of the solar cell string structure 64. It is a structure that can be incident on the solar cell. Since the solar cell module according to the present embodiment also has a light receiving region on the non-light receiving surface (back surface) side of the solar cell, the amount of light incident on the solar cell increases and the amount of power generation can be improved.

[Embodiment 2]
The solar cell module according to the present embodiment has a different structure of the solar cell string structure 64 in the solar cell module of the first embodiment. FIG. 9 is a schematic cross-sectional view of the solar cell string structure 64 according to the present embodiment and the manufacturing process thereof.

The attachment of the single-sided electrode type solar cell 2 and the wiring base material 92 of the present embodiment will be described with reference to FIG.

First, as shown in FIG. 9A, a single-sided electrode type solar cell 2 including an n-type electrode 26 and a p-type electrode 27 provided on one side of a silicon substrate 21 at predetermined intervals is provided. prepare.

Next, a wiring base material 92 in which a plurality of wirings 41 are fixed to one surface by an adhesive 93 is prepared. As the wiring base material 92, an insulating and translucent material is used. In the present embodiment, a resin sheet containing PET as a main component having a thickness of about 75 μm was used as the base material, and copper wiring having a cross-sectional diameter of about 150 μm was used as the wiring. The main component of the base material is not limited to PET, and PEN or the like or glass or the like is used.

The wiring 41 is arranged at a position corresponding to the electrode patterns of the n-type electrode 26 and the p-type electrode 27 of the solar cell 2. That is, the wiring 41 is arranged at the same pitch as the electrodes 26 and 27. The pitches of the electrodes 26 and 27 and the wiring 41 are both about 500 μm.

An uncured fixing resin 94a is installed between the plurality of wirings 41. The fixing resin is for fixing the wiring base material and the single-sided electrode type solar cell, and is installed on at least a part of the wiring base material 92 on which the wiring 41 is not arranged. The fixing resin functions as an adhesive for fixing the wiring base material and the solar cell. The same material can be used for the adhesive 93 and the fixing resin 94a, or different materials can be used.

Examples of the method for installing the fixing resin 94a include screen printing, dispenser coating, and inkjet coating. Of these, it is preferable to use screen printing. The fixed resin 94a can be easily installed at low cost and in a short time.

The width of the fixed resin 94a is preferably smaller than the width between the n-type electrode 26 and the p-type electrode 27 of the single-sided electrode type solar cell 2. This is because the stability of the electrical connection between the electrode of the single-sided electrode type solar cell 2 and the wiring of the base material can be expected to be improved.

In the present embodiment, the case where the fixing resin 94a is installed between the wirings of the base material will be described. However, the fixing resin 94a may be installed between the electrodes of the single-sided electrode type solar cell 2, and the single-sided electrode may be installed. The fixing resin 94a may be installed between the electrodes of the type solar cell 2 and between the wiring of the base material.

The shape of the fixed resin 94a is preferably a line shape along each of the wiring and the n-type electrode 26 and the p-type electrode 27 of the single-sided electrode type solar cell 2, but it is also possible to arrange the fixed resin 94a intermittently. I do not care.

As the fixing resin 94a, it is preferable to use a resin that can be B-staged. The resin that can be B-staged means that when the uncured fixed resin 94a in a liquid state is heated, the viscosity increases to a cured state (first cured state), and then the viscosity decreases as the temperature rises. It is a resin that softens and then softens, and when the temperature rises further, the viscosity rises again and becomes a cured state (second cured state).

Next, the uncured fixing resin 94a is cured to obtain the first cured fixing resin 94b. The uncured fixing resin 94a is cured by heating and / or irradiation with light such as ultraviolet rays to be in the first cured state. As a result, it is possible to obtain the first cured fixed resin 94b having reduced adhesive strength and fluidity as compared with the uncured fixed resin 94a.

Further, the fixed resin 94b in the first cured state has a higher viscosity than the uncured state at room temperature (about 25 ° C.), has shape retention (property that does not deform unless an external force is applied), and It is preferable that the adhesiveness is low (the adhesiveness is such that the fixed resin 94b does not adhere even if the single-sided electrode type solar cell 2 or the wiring base material 92 is brought into contact with the surface of the fixed resin 94b). In this case, a highly productive printing process can be adopted in the process of installing the joining member described later. Further, in the step of superimposing the single-sided electrode type solar cell 2 and the wiring base material 92, which will be described later, even after the single-sided electrode type solar cell 2 and the wiring base material 92 are overlapped, the single-sided electrode type There is a tendency that the solar cell 2 and the wiring base material 92 can be easily removed. Therefore, there is a tendency that the electrode of the single-sided electrode type solar cell 2 and the wiring of the wiring base material 92 can be easily and highly accurately aligned.

When the uncured fixed resin 94a becomes the first fixed resin 94b in the first cured state by heating, the temperature at which the first fixed resin 94b in the first cured state becomes the first fixed resin 94b will be described later. It is preferable that the temperature at which the first fixed resin 94b in the cured state softens and the temperature at which the first fixed resin 94c in the softened state becomes lower than the temperature at which the first fixed resin 94c in the softened state becomes the second cured state. Thereby, by controlling the heating temperature, it is possible to prevent the uncured fixed resin 94a from advancing to the softened state or the second cured state.

Next, the joining member 91 is installed on the surfaces of the n-type electrode 26 and the p-type electrode 27 of the single-sided electrode type solar cell 2. As the joining member 91, a material containing a conductive substance such as solder can be used. The joining member 91 can be installed by, for example, screen printing, dispenser coating, inkjet coating, or the like. Of these, it is preferable to use screen printing. This is because the joining member 91 can be easily installed at low cost and in a short time.

In the present embodiment, the case where the joining member 91 is installed on the electrode of the back electrode type solar cell 2 will be described, but the joining member 91 such as solder is coated as the wiring 41 on the base material. A copper wire may be used, or a joining member 91 may be installed on the electrode of the single-sided electrode type solar cell 2 and on the wiring surface of the base material, respectively. Further, it is not necessary to install both the fixing resin 94a and the joining member 91 on the single-sided electrode type solar cell 2 or the wiring base material 92. For example, between the electrodes of the single-sided electrode type solar cell 2. The fixing resin 94a may be installed, and the joining member 91 may be installed on the wiring surface of the wiring base material 92. Further, instead of the joining member 91 and the fixing resin 94a, ACP is printed on the electrode forming surface side of the single-sided electrode type solar cell 2 or on the surface of the wiring base material 92 facing the single-sided electrode type solar cell 2. May be good. The ACP may be arranged so that the n-type electrode 26 and the p-type electrode 27 of one single-sided electrode type solar cell 2 are not short-circuited, and are preferably arranged in a wider range. ACP enables the connection of electrodes and wiring, and two types of members (joining member 91 and fixing resin 94a).
) Can be replaced only by ACP, so work efficiency can be improved.

Next, as shown in FIG. 9B, the single-sided electrode type solar cell 2 and the wiring base material 92 are overlapped with each other. In the superposition of the single-sided electrode type solar cell 2 and the wiring base material 92, the n-type electrode 26 and the p-type electrode 27 of the single-sided electrode type solar cell 2 are respectively on the insulating wiring base material 92. The wiring 41 corresponding to the n-type electrode 26 and the p-type electrode 27 provided in the above is opposed to each other via the joining member 91.

Next, by heating and / or irradiating light while pressurizing the single-sided electrode type solar cell 2 and the wiring base material 92 that are overlapped as described above, the single-sided electrode type solar cell 2 and the wiring base material 92 are used for wiring. The base material 92 and the base material 92 are bonded together.

Here, the first cured fixed resin 94b is softened by heating and / or irradiation with light such as ultraviolet rays to become a softened fixed resin 94c.

The softened fixed resin 94c located between the electrodes of the single-sided electrode type solar cell 2 is deformed by the pressurization between the single-sided electrode type solar cell 2 and the wiring base material 92, and the wiring base. It gets in between the wirings of the material 92. Further, the conductive substance in the joining member 91 is also melted by being heated, and the electrodes and wiring of the single-sided electrode type solar cell 2 are applied by pressurizing between the single-sided electrode type solar cell 2 and the wiring base material 92. It is deformed with the wiring of the base material 92.

After that, the softened fixed resin 94c is further heated and / or irradiated with light such as ultraviolet rays to increase its viscosity and is cured again to become the second cured fixed resin 94d. Since the second cured state is curing by the cross-linking reaction of the resin, the fixed resin 94d in the second cured state is stable without being softened again. That is, the single-sided electrode type solar cell 2 and the wiring base material 92 can be firmly bonded.

When the solar cell 2 and the wiring base material 92 are crimped as described above, the electrodes 26 and 27 of the solar cell 2 and the plurality of wirings 41 are electrically connected at one time. Further, by crimping the wiring base material 92 to which the plurality of wirings 41 are fixed and the plurality of solar cells 2, it becomes possible to connect the wirings of the adjacent solar cells 2 at once, and the production can be performed. Greatly improved efficiency.

FIG. 10 shows a schematic cross-sectional view of the solar cell module according to the present embodiment. The structure is such that the solar cell string structure 64 is arranged between the translucent base material 81 and the back surface side protective material 82, and the sealing resin 83 is between the translucent base material 81 and the back surface side protective material 82. Is sealed by. The sealing resin 83 and the wiring base material 92 have a translucent property, and the back surface protective material 82 has a property of reflecting light. A sealing resin 83 is interposed between the solar cell string structure 64 and the back surface side protective material 82, and the sunlight SL reflected by the back surface side protective material 82 is a non-light receiving surface (non-light receiving surface of the solar cell string structure 64). It is incident from the back side) side. Since the wiring base material 92 and the fixing resin 94d in the solar cell string structure 64 have translucency, the sunlight SL incident on the solar cell string structure 64 from the non-light receiving surface (back surface) side is the sun. It can enter the battery cell. As described above, in the solar cell module according to the present embodiment, since sunlight is also incident on the non-light receiving surface (back surface) side of the solar cell, the light incident on the solar cell is increased and the amount of power generation can be improved. It becomes.

Further, a sealing step of sealing the solar cell string structure 64 is performed in a state where the single-sided electrode type solar cell 2 and the wiring base material 92 are fixed by the fixing resin 94d, and the sealing step is heated. Since the joining member 91 such as solder melts, it is possible to electrically connect the electrodes 26 and 27 of the solar cell 2 and the wiring of the wiring base material 92 very easily and reliably.

[Embodiment 3]
The solar cell module according to the present embodiment has a different electrode pattern of the single-sided electrode type solar cell in the solar cell module of the first or second embodiment. FIG. 11 is a plan view of the single-sided electrode type solar cell according to the present embodiment as viewed from the electrode forming surface side.

The n-type electrode 26 and the p-type electrode 27 are separated into a plurality of island-shaped portions, and the wiring 41 is electrically connected to the plurality of island-shaped electrodes 26 and 27, respectively. By separating the n-type electrode 26 and the p-type electrode 27 into a plurality of island-shaped portions in this way, the amount of metal used as the electrodes 26 and 27 can be reduced, and the amount of metal used as the electrodes 26 and 27 can be reduced. The manufacturing cost can be suppressed.

[Embodiment 4]
The solar cell module according to the present embodiment has a different electrode pattern of the single-sided electrode type solar cell in the solar cell module of the first or second embodiment. FIG. 12 is a plan view of the single-sided electrode type solar cell according to the present embodiment as viewed from the electrode forming surface side.

All n-type electrodes 26 are connected by an electrode connecting portion 26a, and all p-type electrodes 27 are connected by an electrode connecting portion 27a, respectively. The plurality of wirings 41 are electrically connected to the electrodes 26 and 27, respectively, as in the first and second embodiments. In this way, by connecting all the n-type electrodes 26 and all the p-type electrodes 27 at the electrode connecting portions 26a and 27a, respectively, even if one wiring 41 is broken, the broken wiring can be obtained. The connected electrodes 26, 27 are connected to the electrodes 26, 27 of the adjacent solar cell via the electrode connecting portions 26a, 27a and other non-broken wiring 41, and thus the quality of the solar cell module. And reliability is guaranteed.

[Embodiment 5]
The solar cell module according to the present embodiment uses glass as a translucent base material as the back surface side protective material 82 in the solar cell module of the first embodiment. FIG. 13 is a schematic cross-sectional view of the solar cell module according to the present embodiment.

The structure is such that the solar cell string structure 64 is arranged between the translucent base material 81 (glass) and the back surface side protective material 82 (glass), and the translucent base material 81 (glass) and the back surface side protective material 82 are arranged. It is sealed with (glass) by a sealing resin 83. The sealing resin 83 has translucency. A sealing resin 83 is interposed between the solar cell string structure 64 and the back surface side protective material 82 (glass), but the sunlight SL incident from the back surface side of the solar cell module is the back surface side protective material. It is a structure that allows the solar cell to enter the solar cell from the non-light receiving surface (back surface) side of the solar cell string structure 64 through the 82 (glass) and the sealing resin 83. In the solar cell module according to the present embodiment, since the sunlight incident from the back surface side of the solar cell module can enter the solar cell 2, the light incident on the solar cell 2 increases and the amount of power generation is improved. It will be possible.

[Embodiment 6]
The solar cell module according to the present embodiment uses glass as a translucent base material as the back surface side protective material 82 in the solar cell module of the second embodiment. FIG. 14 is a schematic cross-sectional view of the solar cell module according to the present embodiment.

The structure is such that the solar cell string structure 64 is arranged between the translucent base material 81 (glass) and the back surface side protective material 82 (glass), and the translucent base material 81 (glass) and the back surface side protective material It is sealed with a sealing resin 83 between it and 82 (glass). The sealing resin 83, the wiring base material 92, and the back surface side protective material 82 (glass) have translucency. A sealing resin 83 is interposed between the solar cell string structure 64 and the back surface side protective material 82 (glass), but the sunlight SL incident from the back surface side of the solar cell module is the back surface side protective material. It is a structure that allows the solar cell to enter the solar cell from the non-light receiving surface (back surface) side of the solar cell string structure 64 through the 82 (glass) and the sealing resin 83. Since the wiring base material 92 and the fixing resin 94d in the solar cell string structure 64 have translucency, the sunlight SL incident on the solar cell string structure 64 from the non-light receiving surface (back surface) side is the sun. It can enter the battery cell. In the solar cell module according to the present embodiment, since the sunlight incident from the back surface side of the solar cell module can enter the solar cell 2, the light incident on the solar cell 2 increases and the amount of power generation is improved. It will be possible.

Although the first to sixth embodiments have been specifically described above, the present invention is not limited thereto. The technical scope of the present invention also includes embodiments obtained by appropriately combining the technical means disclosed in each of the above-mentioned six embodiments.

It should be noted that the embodiments disclosed this time are examples in all respects and do not serve as a basis for limited interpretation. Therefore, the technical scope of the present invention is not construed solely by the above-described embodiments, but is defined based on the description of the claims. It also includes all changes within the meaning and scope of the claims.

2 Solar cell 21 Silicon substrate 22 Antireflection film 23 n-type impurity diffusion region 24 p-type impurity diffusion region 25 Passion film 26 n-type electrode 27 p-type electrodes 26a, 27a Electrode connection 32 Solar cell string 41 Wiring 41a, 41b, 41c, 41d Take-out wiring SL Solar 61, 62, 63 Bus bar 64 Solar cell string structure 81 Translucent base material 82 Back side protective material 83 Sealing resin 91 Bonding member 92 Wiring base material 93 Adhesive 94a , 94d Fixed resin

Claims (9)

A plurality of solar cells having a first electrode and a second electrode having a polarity different from that of the first electrode on one surface, and
A plurality of wirings for electrically connecting the first electrode of the first solar cell and the second electrode of the second solar cell adjacent to the first solar cell are provided.
The solar cell has a region on one of the surfaces where neither the first electrode nor the second electrode is arranged.
The wiring has a circular cross-sectional shape.
The first wiring connection portion of the first electrode connected to the wiring, the second wiring connection portion of the second electrode connected to the wiring, and the wiring are arranged in a straight line.
The wiring is arranged at a position corresponding to the first electrode and the second electrode.
The width of the wiring is larger than the width of the first electrode and the second electrode.
A solar cell module having a solar cell string in which a plurality of the solar cell cells are connected in series by the wiring. The solar cell module according to claim 1 before the first wiring connection portion SL, comprising a plurality of sets of the second wiring connection portion and the wire. The wiring is arranged from one end in the longitudinal direction of the first electrode in the first solar cell to the other end in the longitudinal direction of the second electrode in the second solar cell. The solar cell module according to claim 1 or 2. Any of claims 1 to 3, wherein the solar cell string is arranged between two translucent substrates, and the translucent substrate is sealed with a translucent encapsulant. The solar cell module according to item 1. The solar cell module according to any one of claims 4 wherein the wiring claims 1 disposed on the wiring substrate. The solar cell module according to claim 5, wherein a portion of the solar cell in which the first electrode and the second electrode are not arranged and at least a part of the wiring base material are fixed by an adhesive. The solar cell module according to claim 6, wherein the wiring base material and the adhesive are translucent. The first electrode and the second electrode of the solar cell have the positions of the first electrode and the second electrode when the solar cell is rotated by 180 ° in the substrate surface of the solar cell. The solar cell module according to any one of claims 1 to 7, which are arranged so as to be interchanged. In a plan view from the one surface side of the solar cell, the area of the region where none of the first electrode, the second electrode, or the wiring of the solar cell is arranged is the solar cell. The solar cell module according to any one of claims 1 to 8 , which is 50% or more of the area of the solar cell.

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