JP2014022475A - Joining material for solar cell, joining material assembly for solar cell, and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a good connection between electrodes and improve the work efficiency during the connection in a joining material assembly for a solar cell even when an inter-electrode distance between the connection electrode on a rear surface of a solar battery cell and a wiring electrode on a wiring board is large.SOLUTION: A joining material transfer sheet 13 includes: joining materials 10, each of which includes a metal layer 11 including a first end surface 11 and a second end surface 11b, a conductive resin layer 12a formed on the first end surface 11a, and a conductive resin layer 12b formed on the second end surface 11b; and a peeling sheet 14 which adheres tightly with the conductive resin layer 12a of the joining material 10 so as to be peeled. The joining materials 10 are arranged along a sheet surface direction of the peeling sheet 14 while being spaced away from each other.

Description

  The present invention relates to a solar cell bonding material, a solar cell bonding material assembly, and a solar cell module.

Conventionally, electricity generated in a solar cell is concentrated through a bus bar stretched around the surface. However, since this bus bar covers and hides part of the surface of the solar battery cell, there is a problem that the power generation efficiency is lowered.
In order to solve this problem, for example, Patent Document 1 proposes a back contact type solar cell in which both the positive electrode and the negative electrode of the solar cell are installed on the back surface of the cell. This type of solar cells can be connected on the back side of the cell and can prevent a decrease in power generation efficiency without covering the cell surface. Such a solar cell module has a wiring pattern on the back side of the solar cell. A laminated body with a metal foil is used as an alternative circuit for a bus bar, and copper is generally used for these metals because of their conductivity.
However, since copper is expensive, it has also been proposed to use aluminum which is cheaper than copper for wiring.
However, when joining solar cells and wiring, silver paste is conventionally used, and the resistance value becomes larger than copper due to the oxide film generated on the surface by using aluminum. Since the potential difference between the aluminum and silver electrochemical columns is very large, there is a problem that the aluminum corrodes and is insulated in the worst case.
Moreover, even if this is solved, enormous cost of using more expensive silver is required.
As a method for solving these problems, a method of connecting a solar battery cell and a wiring by using a conductive material containing metal particles has been proposed (see Patent Document 2).

JP 2005-011869 A JP 2009-302327 A

However, the prior art as described above has the following problems.
In the technique described in Patent Document 2, since the back contact type solar cells are connected using a conductive material containing metal particles, it is easy to electrically connect even an aluminum wiring. However, in the connection using such a conductive material, it is necessary to reduce the distance between the circuit board and the solar battery cell.
On the other hand, the solar cell has an outer periphery made of a sealing material, for example, in order to increase the durability in use over time, such as suppressing the intrusion of moisture or the like, or to increase the resistance to vibration and impact when an external force is applied. It is necessary to seal. For this reason, it is calculated | required that the distance between electrodes between a photovoltaic cell and a circuit board should be enlarged to some extent.
Therefore, when connecting a solar cell and a circuit board with a conductive material, when ensuring good conductivity, the inter-electrode distance between the solar cell and the circuit board should be set to a suitable distance. There is a problem that it may not be possible.
Even if the necessary distance between the electrodes can be set, the conductive material contains expensive metal particles such as silver (Ag) in order to make such a connection. The usage amount of the functional material increases. For this reason, there exists a problem that manufacturing cost increases.

  The present invention has been made in view of the above problems, and even when the interelectrode distance between the connection electrode on the back surface of the solar battery cell and the wiring electrode on the wiring substrate is large, the electrodes are excellent. It is an object of the present invention to provide a solar cell bonding material, a solar cell bonding material assembly, and a solar cell module that can be connected to each other and that can improve work efficiency during connection.

  In order to solve the above-described problem, the solar cell bonding material according to the first aspect of the present invention includes a connection electrode of the solar battery cell provided on the back surface opposite to the light receiving surface of the solar battery cell, and a wiring. A solar cell bonding material for bonding a wiring electrode on a substrate and electrically connecting the connection electrode and the wiring electrode to each other, the first end face in one of the thickness directions, A metal bonding material body having a second end surface located on the opposite side of the thickness direction with respect to the one end surface; a first conductive resin layer formed on the first end surface of the bonding material body; And a second conductive resin layer formed on the second end face of the bonding material main body.

  Moreover, in the solar cell bonding material according to the first aspect of the present invention, the bonding material body protrudes from the first end surface toward the first conductive resin layer at the outer peripheral portion of the first end surface. It is preferable that the outer peripheral portion of the second end face has a protrusion protruding from the second end face toward the second conductive resin layer.

  In the solar cell bonding material according to the first aspect of the present invention, the bonding material body is preferably made of aluminum or an aluminum alloy.

  The solar cell bonding material assembly according to the second aspect of the present invention includes a plurality of solar cell bonding materials according to the first aspect of the present invention, and the first conductive resin of the plurality of solar cell bonding materials. And a release sheet that comes into close contact with at least one of the layer and the second conductive resin layer, and the plurality of solar cell bonding materials are separated from each other along the sheet surface direction of the release sheet It is set as the structure arrange | positioned.

  Moreover, in the solar cell bonding material assembly according to the second aspect of the present invention, the plurality of solar cell bonding materials are symmetrical with the arrangement pattern of the connection electrodes of the solar cells on the release sheet. It is preferable that they are arranged in an arrangement pattern.

  In the solar cell bonding material assembly according to the second aspect of the present invention, it is preferable that the release sheet has an identification mark for identifying the position of the solar cell bonding material.

  The solar cell module according to the third aspect of the present invention includes a solar cell in which a connection electrode is provided on the back surface opposite to the light receiving surface, a wiring substrate having a wiring electrode, and the first aspect of the present invention. A solar cell bonding material, wherein the connection electrode of the solar battery cell and the wiring electrode on the wiring substrate are electrically connected by the solar cell bonding material.

  In the solar cell module according to the fourth aspect of the present invention, the solar cell bonding material assembly according to the second aspect of the present invention is applied to one of the connection electrode of the solar battery cell and the wiring electrode on the wiring board. The second conductive resin layer of the solar cell bonding material is overlapped and bonded, and then the release sheet is peeled to place the solar cell bonding material on one of the connection electrode and the wiring electrode. It is set as the structure manufactured by transcribe | transferring and bonding the other of the said connection electrode and the said electrode for wiring to the said 1st conductive resin layer of the said solar cell bonding material.

  According to the solar cell bonding material, the solar cell bonding material assembly, and the solar cell module of the present invention, the first conductive resin layer and the first end surface of the metal bonding material main body on the first end surface and the second end surface, respectively. Since the conductive resin layer 2 is formed, even when the interelectrode distance between the connection electrode on the back surface of the solar battery cell and the wiring electrode on the wiring substrate is large, the electrodes can be connected well, and There is an effect that work efficiency at the time of connection can be improved.

It is typical sectional drawing which shows the structure of the solar cell module of the 1st Embodiment of this invention. It is a typical top view which shows the board | substrate part of the solar cell module of the 1st Embodiment of this invention. It is the typical top view which shows the structure of the joining material assembly for solar cells of the 1st Embodiment of this invention, and its AA sectional drawing. It is the elements on larger scale of the B section in FIG. It is process explanatory drawing explaining an example of the manufacturing process of the bonding | jointing material assembly for solar cells of the 1st Embodiment of this invention. It is process explanatory drawing explaining an example of the manufacturing process of the solar cell module of the 1st Embodiment of this invention. It is process explanatory drawing explaining an example of the manufacturing process following FIG. 6 of the solar cell module of the 1st Embodiment of this invention. It is process explanatory drawing explaining an example of the manufacturing process following FIG. 7 of the solar cell module of the 1st Embodiment of this invention. It is typical sectional drawing which shows the structure of the joining material assembly for solar cells used for the solar cell module of the modification (1st modification) of the 1st Embodiment of this invention. It is typical sectional drawing which shows the structure of the solar cell module of the 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and common description is omitted.

[First Embodiment]
The solar cell bonding material, solar cell bonding material assembly, and solar cell module according to the first embodiment of the present invention will be described.
FIG. 1 is a schematic cross-sectional view showing the configuration of the solar cell module according to the first embodiment of the present invention. FIG. 2 is a schematic plan view showing a substrate portion of the solar cell module according to the first embodiment of the present invention. FIG. 3A is a schematic plan view showing the configuration of the solar cell bonding material assembly according to the first embodiment of the present invention. FIG.3 (b) is AA sectional drawing in Fig.3 (a). FIG. 4 is a partially enlarged view of a portion B in FIG.

  As shown in FIG. 1, the schematic configuration of the solar cell module 50 of the present embodiment includes a plurality of wiring connection electrodes 20 a on the back surface 20 c (back surface portion) opposite to the light receiving surface 20 b that receives light for power generation. Solar cell 20 provided, substrate unit 55 for wiring solar cell 20, bonding material 10 (bonding material for solar cell) for electrically connecting substrate unit 55 and solar cell 20, and substrate unit 55 And a sealing material 30 stacked on the solar battery cell 20 to seal the solar battery cell 20, and a translucent substrate 40 stacked on the sealing material 30.

The solar battery cell 20 is a semiconductor element that generates electricity by photoelectrically converting light incident from the light receiving surface 20b. As a method of the solar battery cell 20, an appropriate method can be adopted as long as it is a so-called back contact type solar battery cell in which the connection electrode 20 a is provided on the back surface 20 c. Although FIG. 1 is a schematic diagram, the illustration is simplified, but the number of connection electrodes 20a can be appropriately set to 2 or more as needed (see the two-dot chain line in FIG. 2).
The connection electrode 20a is formed in a circular shape with a diameter w _20a , for example, and the material is made of, for example, a baked silver paste. The connection electrodes 20a may be different in size and shape, but in the following description, each connection electrode 20a is described as having the same size and shape as an example.

Moreover, as shown in a two-dot chain line in FIG. 2, for example, an appropriate shape such as a rectangular shape in a plan view can be adopted as the plan view shape of the solar battery cell 20.
Further, in FIG. 2, only one solar battery cell 20 is shown, but as shown in FIG. 1, a plurality of solar battery cells 20 in the solar battery module 50 are arranged along the surface direction of the substrate portion 55. Two or more are arranged next to each other with a gap. In the present embodiment, although not shown in the figure, a plurality of them are arranged adjacent to each other with a gap in the left-right direction and the depth direction shown in FIG. 1, thereby arranging them in a rectangular lattice shape in plan view. ing.

  As shown in FIG. 1, the substrate portion 55 of this embodiment includes a back sheet 54, a base material 51 (wiring substrate), an insulating adhesive layer 52, and an aluminum electrode 53 (wiring electrode) stacked in this order. It has been done.

The back sheet 54 constitutes one outer surface in the stacking direction of the substrate portion 55 to suppress moisture, oxygen, and the like from entering the inside of the substrate portion 55 and the inside of the solar cell module 50. It is a sheet-like member. For this reason, the back sheet 54 has a barrier function as a shield material.
As a material of the back sheet 54, an appropriate resin material having excellent barrier property against moisture and oxygen, an aluminum foil, or a composite laminated film of an aluminum foil and an appropriate resin can be used.

The base material 51 is a member formed by laminating on the back sheet 54, and is a member that supports the aluminum electrode 53 via the insulating adhesive layer 52. In this embodiment, the base material 51 is composed of a flexible sheet-like member. Is done. Moreover, it is preferable that the base material 51 consists of a material excellent in electrical insulation.
For example, the base material 51 can employ a resin material formed into a sheet shape or a film shape.
As a material of the base material 51, for example, a resin material such as acrylic, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polyimide, urethane, epoxy, melamine, styrene, or a resin material obtained by copolymerizing them can be used. .
Moreover, the material of the base material 51 can also use the material which mixed the organic filler or the inorganic filler etc. as needed for control of heat insulation, elasticity, or an optical characteristic.
The base material 51 can also employ a laminated film in which a plurality of the above resin materials are laminated or a composite laminated film in which a layer of the above resin material and a metal foil such as an aluminum foil are laminated. is there.
Also, for example, when the above-mentioned composite laminated film is used, the back sheet 54 is deleted when the base material 51 has the necessary strength and moisture or oxygen barrier properties as the outer surface of the solar cell module 50. However, the base material 51 may serve as the function of the back sheet 54.

  The insulating adhesive layer 52 is a layered portion for fixing the aluminum electrode 53 to the surface of the base material 51. For example, urethane, acrylic, epoxy, polyimide, olefin, which is a curable resin, or a copolymer thereof. It is formed by curing the cured curable adhesive. The kind of curable adhesive is not specifically limited, For example, a thermosetting adhesive, a UV curable adhesive, etc. can be employ | adopted suitably. Further, an adhesive layer that is not a step curable type may be used as the insulating adhesive layer 52.

The aluminum electrode 53 forms a wiring pattern for wiring the solar battery cells 20. The aluminum electrode 53 has an appropriate plan view shape according to the arrangement of the connection electrodes 20 a of the solar battery cells 20, and has an insulating adhesive layer 52 interposed therebetween. And laminated on the base material 51 and integrally joined to the base material 51.
As a wiring pattern of the aluminum electrode 53, for example, as shown in FIG. 2, four linear portions 53a ₁ , 53a ₂ , 53a ₃ , 53a ₄ (hereinafter referred to as linear portions 53a ₁ to 53a ₄ ) having a substantially constant line width. 53a ₄ may be described as a comb-tooth-shaped portion 53A and four linear portions 53b ₁ , 53b ₂ , 53b ₃ , 53b ₄ (which have a substantially constant line width). Hereinafter, the linear portions 53b _{1 to} 53b ₄ may be described as comb-shaped portions 53B arranged in a comb-tooth shape, and these comb-tooth-shaped portions 53A and 53B are connected to each other. An example of the pattern that penetrates into the gap between the shaped parts and is arranged in close proximity to each other can be given.
In the following, the direction in which the linear portions 53a _{1 to} 53a ₄ and 53b _{1 to} 53b ₄ extend (the vertical direction in FIG. 2) is the length direction of the aluminum electrode 53, and the linear portions 53a _{1 to} 53a ₄ , 53b orthogonal to this. The line width direction of _{1 to} 53b ₄ (the left-right direction in FIG. 2) may be referred to as the width direction of the aluminum electrode 53.

In this example, the comb-like portions 53A and 53B correspond to the positive electrode wiring and the negative electrode wiring of the power generation output, respectively. Also, above the comb-like portions 53A and 53B (on the translucent substrate 40 side), as shown by a two-dot chain line in FIG. 2, the solar battery cell 20 is positioned so as to cover the comb-like portions 53A and 53B from above. Is placed. In such a connection position, the solar battery cell 20 includes a total of 24 connection electrodes 20a (two points in FIG. 2), three above each of the linear portions 53a _{1 to} 53a ₄ and 53b _{1 to} 53b ₄ . (See chain line).
On the linear portion _53a of each pattern of the aluminum electrode _{53 1 ~53a 4, 53b 1 ~53b} 4 is a opposable position to the connection electrode 20a, the bonding material 10 to be described later is bonded by three respectively.
In addition, the shape of the pattern of the aluminum electrode 53 shown in FIG. 2 and the number and arrangement of the connection electrodes 20a of the solar battery cells 20 are examples and are not limited thereto.

  As a material of the aluminum electrode 53, it is desirable to use, for example, high-purity aluminum such as 1N30 material in order to ensure as good electrical conductivity as possible.

As shown in FIG. 1, the bonding material 10 of the present embodiment includes a conductive resin layer 12 a (first conductive resin layer) and a metal layer 11 (bonding material body) from the aluminum electrode 53 toward the connection electrode 20 a. , And conductive resin layer 12b (second conductive resin layer) are laminated in this order. Thereby, the aluminum electrode 53 and the connection electrode 20a are electrically connected to each other.
In the present embodiment, the shape of the bonding material 10 in plan view is not particularly limited as long as it does not short-circuit between the comb-like portions 53A and 53B and between the connection electrodes 20a.
In the present embodiment, as an example, circular linear portion _53a 1 _{~53a 4, 53b} 1 smaller than the line width of ～53B _4, and smaller diameter _{w 10} than the connection electrode 20a of the solar cell 20 of the aluminum electrode 53 It is said.
This material of the portion bonding material 10 is not connected to have a shape larger than the linear portion _53a 1 _{~53a 4, 53b} 1 line width of ～53B ₄ of diameter and aluminum electrodes 53 of the connection electrode 20a is wasted Because. Further, if smaller than the linear portion _53a 1 _{~53a 4, 53b} 1 line width of ～53B ₄ of the outer shape of the bonding material 10 connecting electrode 20a of the diameter and the aluminum electrode 53, positional deviation occurs when connecting Also in this case, it is also possible to reduce the possibility of short-circuiting with the other electrode that protrudes from the connection electrode 20a and the linear portions 53a _{1 to} 53a ₄ and 53b _{1 to} 53b ₄ .

However, this is an example, and the shape of the bonding material 10 in plan view may be, for example, the same shape as the connection electrode 20a or a shape larger than the connection electrode 20a. Further, when the size and shape of the connection electrodes 20a are different, the size and shape can be appropriately changed in accordance with the size and shape of the connection electrode 20a to be joined. A planar shape of the bonding material 10, the same applies with respect to the linear portion _{53a 1 ~53a 4, 53b 1 ~53b} 4 of the line width of the aluminum electrode 53.
Therefore, the shape and size of the outer shape in the direction orthogonal to the connecting direction of the bonding material 10 (the vertical direction in FIG. 1) are the linear portions 53a _{1 to} 53a ₄ and 53b ₁ to shape 53b _4, and size, determined in advance in accordance with the magnitude of the positional deviation in the direction perpendicular to the connection direction that may occur when connecting.

  In this embodiment, the bonding material 10 is supplied in the form of a bonding material transfer sheet 13 (a bonding material assembly for solar cells) as shown in FIGS. 3 (a), 3 (b), and 4, and the solar cell module. Used in the manufacture of 50. Therefore, hereinafter, the configuration of the bonding material 10 will be described together with the configuration of the bonding material transfer sheet 13 of the present embodiment.

As shown in FIGS. 3A and 3B, the bonding material transfer sheet 13 is a sheet-like member in which a plurality of bonding materials 10 are closely attached to the release sheet 14.
As the release sheet 14, a sheet cut into an appropriate size or a long tape-shaped sheet can be adopted. In this embodiment, it consists of a long tape having a short width that can cover each connection electrode 20a of one solar battery cell 20.
One surface 14a of the release sheet 14 has a releasability with respect to the conductive resin layer 12a, so that it can come into close contact with the conductive resin layer 12a.
Further, the other surface 14b of the release sheet 14 has a releasability with respect to the conductive resin layer 12b, so that the bonding material 10 is not transferred to the surface 14b side even when the release resin 14 is laminated with the conductive resin layer 12b. ing.

On the front surface 14a of the release sheet 14, an arrangement pattern that is in a line-symmetrical positional relationship with the arrangement pattern of each connection electrode 20a when viewed from the back surface 20c side of one solar battery cell 20 is formed. The same number of bonding materials 10 are in close contact with each conductive resin layer 12a. For this reason, when the conductive resin layer 12b of each bonding material 10 disposed on the release sheet 14 is faced to each connection electrode 20a of the solar battery cell 20, it is possible to face each other at positions facing each other. .
When such a group of bonding materials 10 is referred to as a unit group U, a plurality of unit groups U are arranged at a constant pitch along the longitudinal direction of the release sheet 14.
On the release sheet 14 in the vicinity of each unit group U, identification marks 14c and 14d for representing position information of the release sheet 14 are formed by, for example, printing, stamping, punching, or the like.
The shapes and positions of the identification marks 14 c and 14 d are not particularly limited as long as a coordinate system for specifying the position information of the bonding material 10 in the unit group U can be set on the release sheet 14.
In the present embodiment, as an example, the respective positions can be specified at the two corners corresponding to the diagonal positions of the rectangular region 20A (see FIG. 3A) where the connection electrodes 20a of the solar battery cells 20 are arranged. Cross-shaped identification marks 14c and 14d are formed. For this reason, the arrangement position of each bonding material 10 can be represented by a rectangular coordinate system determined by the identification marks 14c and 14d.
In addition, when forming the identification marks 14c and 14d by printing, it forms in either one or both of the surfaces 14a and 14b of the peeling sheet 14 as needed.
According to such identification marks 14c and 14d, for example, by acquiring position information of the identification marks 14c and 14d by image recognition or detection by an optical sensor from an image captured by a camera, the position of each bonding material 10 is obtained. Can be specified.
For example, the identification marks 14c and 14d are omitted when the position of the bonding material 10 can be specified from the image of the bonding material 10 on the release sheet 14 or when position measurement is not necessary due to the conveyance accuracy of the release sheet 14. May be.

  In this embodiment, such a bonding material transfer sheet 13 is wound in a roll shape, and can be unwound and used as necessary. At that time, since the surface 14b has good releasability with respect to the conductive resin layer 12b, the bonding material 10 on the lower layer side is not transferred onto the surface 14b of the peeled release sheet 14.

The conductive resin layer 12a of the bonding material 10 is for electrically connecting the metal layer 11 and the aluminum electrode 53 as shown in FIG. 1, and the thickness of the metal layer 11 as shown in FIG. It is formed on the first end face 11a which is one end face in the direction.
As the conductive resin layer 12a, a conductive adhesive or a conductive adhesive film used for element mounting can be used.
As an example of the conductive resin layer 12a, there may be mentioned a configuration in which conductive particles are contained in a thermosetting resin such as urethane, acrylic, epoxy, polyimide, olefin, or a curable adhesive obtained by copolymerizing these. it can.
Examples of the conductive particles include copper particles, zinc particles, silver particles, gold particles, nickel particles, or particles obtained by performing metal plating similar to these on the surface of polymer particles.
In order to reduce the cost of the conductive resin layer 12a, it is desirable to contain inexpensive zinc particles, nickel particles, or both.
In particular, when the conductive resin layer 12a contains silver particles, zinc particles, and nickel particles, each has high rigidity. For example, when pressed against aluminum or copper, oxide films formed on these surfaces Is broken through. For this reason, even if an oxide film is formed, electrical connection can be easily made.

Moreover, such a conductive resin layer 12a is cured by being heated, and is bonded to a mating member.
As the heating method, for example, techniques such as vacuum pressure lamination, oven heating, and hot plate heating can be used.

The thickness t _12a of the conductive resin layer 12a is set to a thickness that allows good electrical connection to the aluminum electrode 53 and the metal layer 11.
A preferable thickness for the conductive resin layer 12a is, for example, about 10 μm to 50 μm. If conductive particles having a small particle diameter are used, the thickness of the conductive resin layer 12a can be made thinner than 10 μm.

As shown in FIG. 1, the metal layer 11 is a conductive member that conducts the aluminum electrode 53 and the connection electrode 20a through the conductive resin layers 12a and 12b, and is a metal or alloy, or a composite of metal and alloy. It is a plate-shaped conductive member made of a body. In the present embodiment, the outer shape in the direction orthogonal to the connection direction is the same as that of the conductive resin layers 12a and 12b.
Metal layer 11, as shown in FIG. 4, respectively one and the other in the thickness direction, the first end surface 11a, has a second end face 11b, the thickness of the metal layer 11 is t _11. A conductive resin layer 12a is laminated on the first end surface 11a, and a conductive resin layer 12b described later is laminated on the second end surface 11b.
Further, in the present embodiment, the outer peripheral portion of the first end surface 11a, the protrusion 11c of the maximum height is the height h _11c projecting toward the conductive resin layer 12a from the first end face 11a is formed.
The protrusion 11c is a burr formed on the outer peripheral portion of the first end surface 11a by punching the metal layer 11. In the present embodiment, the height h _11c of the protrusion 11c is smaller than the thickness t _12a of the conductive resin layer 12a. Therefore, the protrusion 11c is buried in the layer thickness of the conductive resin layer 12a. . Therefore, the bonding strength between the first end face 11a and the conductive resin layer 12a is improved by the protrusion 11c.

However, the height of the protrusion 11c may be equal to or greater than the thickness of the conductive resin layer 12a. In this case, it is preferable that the amount of protrusion from the conductive resin layer 12 a does not exceed the thickness of the aluminum electrode 53.
Thus, when the protrusion part 11c protrudes from the conductive resin layer 12a, since the metal layer 11 and the aluminum electrode 53 conduct | electrically_connect also when the protrusion part 11c contact | abuts to the aluminum electrode 53, electroconductivity is further improved. It is possible.
In the present embodiment, since the conductive resin layer 12a is formed of a material or thickness that can provide good adhesion and conductivity, the protrusion 11c is not an essential configuration. For this reason, the metal layer 11 may be processed by a processing method such as laser processing or water jet processing that does not generate burrs on the outer periphery.

The metal layer 11 can be formed by cutting a metal foil sheet or a plate material. The ready-made member, when the thickness t ₁₁ is not obtained the required, or scraped off-the-shelf member, rolling or, or by deposition, may increase or decrease the thickness.
Further, the thickness may be adjusted by joining a plurality of pieces by soldering or the like.
Further, a sheet material having a necessary thickness may be formed by film formation.
Since the metal layer 11 is composed of only a metal or an alloy, the conductivity does not deteriorate even if the thickness is increased.
Thus, no particular restriction on the thickness t ₁₁ of the metal layer 11, moreover it is easy to change. Therefore, the thickness t ₁₁ of the metal layer 11 can be set to a thickness of as appropriate according to the inter-electrode gap to be secured between the aluminum electrode 53 and the connection electrode 20a.

The material of the metal layer 11 is not particularly limited as long as it is a metal or an alloy that can obtain conductivity. For example, a metal selected from gold, silver, copper, aluminum, iron, or the like, or an alloy containing these as a main component. Can be adopted. However, it is more preferable to use copper, aluminum, or an aluminum alloy from the viewpoint of low cost and conductivity.
In the present embodiment, as an example, it employs an aluminum foil or an aluminum plate having a thickness of t _11.

The conductive resin layer 12b connects the second end surface 11b, which is the end surface opposite to the first end surface 11a in the thickness direction of the metal layer 11, and the connection electrode 20a of the solar battery cell 20, and is electrically conductive. Similarly to the resin layer 12a, a conductive adhesive or a conductive adhesive film used for element mounting can be used. That is, a material suitable for the conductive resin layer 12a exemplified above can also be used for the conductive resin layer 12b.
The materials of the conductive resin layers 12a and 12b and the thicknesses _t12a and _t12b may be the same. However, as long as the electrical connection performance with the metal layer 11 is not impaired, the aluminum electrode 53 and the connection electrode 20a, respectively. In consideration of ease of electrical connection and durability, the material, thickness, particle diameter of conductive particles, surface roughness, and the like may be adopted.
For example, when the material of the aluminum electrode 53 and the connection electrode 20a is different, or when the temperature condition of the connection part between the aluminum electrode 53 and the connection electrode 20a is different, the conductivity is changed according to the condition of each connection part. The material and thickness of the conductive resin layers 12a and 12b, the particle diameter of the conductive particles, the roughness of the surface, and the like can be changed.

Such a bonding material transfer sheet 13 can be manufactured as follows.
FIGS. 5A, 5 </ b> B, and 5 </ b> C are process explanatory views illustrating an example of a method for manufacturing the solar cell bonding material assembly according to the first embodiment of the present invention.

First, as shown in FIG. 5A, a release sheet 14, a conductive resin layer 12a, a metal layer sheet 11A made of a sheet member made of the same material as the metal layer 11, and a conductive resin layer 12b were laminated in this order. A stacked body 13A is formed.
The formation method of 13 A of laminated bodies is not specifically limited. For example, in this embodiment, since an aluminum foil or an aluminum plate is used as the metal layer 11, a sheet of the conductive resin layer 12a with the release sheet 14 on one surface of an aluminum foil (aluminum plate) sheet that is the metal layer sheet 11A. The members are bonded to each other and formed by transferring only the conductive resin layer 12b from the sheet member of the conductive resin layer 12b with an unillustrated release sheet to the other surface of the aluminum foil (aluminum plate) sheet. be able to.

Next, as shown in FIG. 5B, half-cut processing is performed from the conductive resin layer 12 b side by the punching blade C in order to form the outer shape of the metal layer 11.
By this step, although not shown in FIG. 5B, a protrusion 11c as shown in FIG. 4 is formed.

Next, as shown in FIG. 5C, the unnecessary portion 13B outside the punching blade C is peeled off and removed so that the portion inside the punching blade C remains on the release sheet 14 side.
Thereby, the bonding material transfer sheet 13 is manufactured.
These processes can be continuously performed by a roll-to-roll method.

If the sealing material 30 can seal and insulate the photovoltaic cell 20 on the aluminum electrode 53 and the insulating adhesive layer 52 of the board | substrate part 55, it can be comprised from an appropriate material. Suitable materials for the sealing material 30 include a film material made of a thermoplastic resin, for example, an ethylene / vinyl acetate copolymer (EVA), an ethylene / methacrylic acid copolymer (EMAA), or the like.
When the sealing material 30 is composed of these thermoplastic resin films, the sealing material 30 can be formed by laminating two or more thermoplastic resin films so as to sandwich the solar battery cell 20.

  The translucent substrate 40 is a member that guides incident light to the light receiving surface 20 b of the solar battery cell 20 and forms an outer surface opposite to the back sheet 54 in the solar battery module 50. In this embodiment, the structure which adhere | attached the glass panel on the surface of the sealing material 30 is employ | adopted.

Next, a method for manufacturing such a solar cell module 50 will be described.
6 (a), 6 (b), and 6 (c) are process explanatory views illustrating an example of the manufacturing process of the solar cell module according to the first embodiment of the present invention. FIG. 7 is a process explanatory diagram illustrating an example of a manufacturing process subsequent to FIG. 6C of the solar cell module according to the first embodiment of the present invention. FIG. 8 is a process explanatory diagram illustrating an example of a manufacturing process subsequent to FIG. 7 for the solar cell module according to the first embodiment of the present invention.

In order to manufacture the solar cell module 50, first, the bonding material 10 is transferred from the bonding material transfer sheet 13 to the connection electrode 20 a of the solar battery cell 20.
For example, as shown in FIG. 6A, the solar cells 20 are arranged on the work base 100 with the connection electrodes 20a facing upward. The work base 100 may be a fixed table or a moving table on which the solar cells 20 are placed and move in a certain direction.
Then, the bonding material transfer sheet 13 is disposed above each connection electrode 20a of the solar battery cell 20 so that the conductive resin layer 12b faces. At this time, images of the identification marks 14c and 14d on the release sheet 14 are obtained by a camera (not shown) and the like, the position analysis is performed, and each bonding material 10 on the release sheet 14 and each of the solar cells 20 The position with the connection electrode 20a is adjusted.
For example, if the bonding material transfer sheet 13 is rolled, the bonding material transfer sheet 13 is unwound and the unit group U of the bonding material 10 is moved onto the solar battery cell 20.
In the present embodiment, the bonding material 10 on the release sheet 14 has the same number of bonding materials 10 as the connection electrodes 20a of one solar battery cell 20 arranged at line-symmetric positions for each unit group U. For this reason, if the joining material 10 and connection electrode 20a of two appropriate places are made to oppose, all the joining materials 10 on the unit group U and all the connection electrodes 20a on the photovoltaic cell 20 will mutually oppose. It will be.

Next, as shown in FIG. 6A, the pressing jig 101 having a plurality of pressing portions 101 a corresponding to the arrangement pattern of the connection electrodes 20 a in the solar battery cell 20 is connected to the release sheet 14 side in the bonding material transfer sheet 13. The pressing jig 101 is pressed toward the release sheet 14 as shown in FIG.
As a result, each bonding material 10 is pressed against the connection electrode 20a, and the conductive resin layer 12b of the bonding material 10 is in close contact with and bonded to the connection electrode 20a.
The adhesive strength at this time may be higher than the adhesive strength between the conductive resin layer 12a and the release sheet 14 and may be such that the bonding material 10 does not fall off during the transportation of the solar battery cell 20. Further, the conductive particles in the conductive resin layer 12b may be in a state where they are not electrically connected to the connection electrode 20a.

Next, as shown in FIG.6 (c), the press jig | tool 101 is evacuated and the peeling sheet 14 is peeled. At this time, since the adhesive force between the connection electrode 20a and the conductive resin layer 12b is larger than the adhesive force between the release sheet 14 and the conductive resin layer 12a, the bonding material 10 is transferred to the solar cell 20 side, and the release sheet Only 14 is peeled off.
Thus, the solar cell 21 with a bonding material in which the bonding material 10 is bonded to each connection electrode 20a of the solar cell 20 is formed.

A substrate portion 55 is formed in parallel with the above steps.
In order to form the board | substrate part 55, the aluminum foil sheet used as the material of the back sheet | seat 54, the base material 51, the insulating adhesive layer 52, and the aluminum electrode 53 is laminated | stacked in this order. At this time, an appropriate adhesive is also disposed between the back sheet 54 and the base material 51.
Next, this laminate is bonded by, for example, a dry laminating method.
Next, the aluminum foil sheet in this laminated body is patterned to form an aluminum electrode 53.
As the patterning method, for example, an etching method can be employed. That is, after a resist is applied on the aluminum foil sheet, the resist is patterned so as to correspond to the wiring pattern of the aluminum electrode 53, and the aluminum foil sheet not covered with the resist is removed by chemical etching, so that the aluminum electrode 53 Form. Thereafter, the resist on the aluminum electrode 53 is removed.
In this way, the substrate portion 55 is formed as shown in FIG.
Such a laminate may be formed by forming the insulating adhesive layer 52 and the aluminum electrode 53 on the substrate 51 and then bonding the back sheet 54 to the back surface of the substrate 51.

Next, as shown in FIG. 7, the board | substrate part 55, the lower side sealing material film 32, the photovoltaic cell 21 with a joining material, the upper side sealing material film 31, and the translucent board | substrate 40 are piled up in this order, and are arrange | positioned. .
Here, the lower sealing material film 32 and the upper sealing material film 31 are for forming the sealing material 30, and both are made of the same thermoplastic resin film as the sealing material 30.
The lower sealing material film 32 is a film member having a thickness that substantially corresponds to the height of the bonding material 10.
Further, the lower sealing material film 32 is provided with a through hole 32a for allowing the bonding material 10 of the solar cell with bonding material 21 to be inserted.
The upper sealing material film 31 is a film member having a thickness that substantially corresponds to the layer thickness from the back surface 20 c of the solar battery cell 20 to the translucent substrate 40 in the solar battery module 50.
Since the upper sealing material film 31 covers the light receiving surface 20b of the solar battery cell 20, it is necessary to use a transparent film having optical transparency.
However, since the lower sealing material film 32 forms at least the region of the sealing material 30 below (the substrate part 55 side) from the light receiving surface 20b, it does not require light transmittance. For this reason, the lower sealing material film 32 can employ various films having light absorption, light scattering, and light reflectivity. For example, a colored (including white) film containing a color material having a suitable color, such as a black film or a white film, can be suitably employed.
By adopting such a colored film as the lower sealing material film 32, the surface of the substrate portion 55 cannot be visually recognized from the light transmissive substrate 40 side through the gaps between the solar cells 20. The design property of can be improved.

Next, as shown in FIG. 8, in the state where each bonding material 10 of the solar cell 21 with bonding material is inserted into the through hole 32 a of the lower sealing material film 32, the substrate portion 55, the lower sealing material A laminated body 50A in which the film 32, the solar battery cell 21 with the bonding material, the upper sealing material film 31, and the translucent substrate 40 are laminated is formed.
At this time, it is preferable that the connection electrode 20a and the conductive resin layer 12b, and the aluminum electrode 53 and the conductive resin layer 12a are all in contact with each other.

Next, using a laminator, vacuum pressurization laminating is performed under vacuum, in which the stacked body 50A is heated and pressed in the stacking direction.
The processing conditions of the heating temperature and the applied pressure at this time are temperatures at which the lower sealing material film 32 and the upper sealing material film 31 are softened and deformed, and can be adhered and adhered to the surfaces of adjacent members. In addition, the heating temperature and the applied pressure are such that the conductive resin layer 12b and the connection electrode 20a can be joined to the conductive resin layer 12a and the aluminum electrode 53.

By the laminating process, the conductive resin layer 12a sandwiched between the aluminum electrode 53 and the first end surface 11a of the metal layer 11 and between the connection electrode 20a and the second end surface 11b of the metal layer 11 respectively. , 12b are pressurized and heated in the thickness direction.
Thereby, the conductive resin layers 12a and 12b are cured, and the metal layer 11, the aluminum electrode 53, and the connection electrode 20a are bonded.
In addition, the conductive particles in the conductive resin layers 12a and 12b are in contact with and in close contact with the first end surface 11a and the aluminum electrode 53 of the metal layer 11, and the second end surface 11b of the metal layer 11 and the connection electrode 20a, respectively. . At this time, even when an oxide film is formed on the surfaces of the metal layer 11, the aluminum electrode 53, and the connection electrode 20a, the oxide film is pierced by the stress concentration generated on each surface by contact with the conductive particles. Thus, an electrical connection is obtained.

Moreover, the lower sealing material film 32 and the upper sealing material film 31 are softened and deformed and integrated by the heating of the laminating process. Moreover, the lower sealing material film 32 and the upper sealing material film 31 that have been softened flow and are in close contact with the surfaces of adjacent members. Thereby, the outer peripheral part of the photovoltaic cell 20 is sealed, and the layer of the sealing material 30 is formed between the substrate part 55 and the translucent substrate 40.
Thus, when heating is complete | finished, it solidifies in the state which each layer of 50 A of laminated bodies adhered, and the solar cell module 50 as shown in FIG. 1 is formed.

According to such a solar battery module 50, when the solar battery cell 20 and the substrate part 55 are electrically connected, an aluminum oxide film is formed on the surface of the aluminum electrode 53. Therefore, special processing is required for soldering or the like. On the other hand, in the present embodiment, by using the conductive resin layer 12a, it is possible to perform electrical connection satisfactorily without performing surface treatment or the like for removing the oxide film. For this reason, the process of electrical connection is simplified.
Moreover, since the photovoltaic cell 20 and the board | substrate part 55 are connected by the joining material 10, even if thickness changes, the thickness of the metal layer 11 with which favorable electroconductivity is obtained is set to appropriate thickness. Only by this, the interelectrode distance between the connection electrode 20a and the aluminum electrode 53 can be changed.
In addition, the conductive resin layers 12a and 12b can employ a certain thickness and material that can provide the necessary adhesive strength and conductivity between the aluminum electrode 53 and the connection electrode 20a, respectively.
Therefore, the connection electrode 20a and the aluminum electrode 53 can be electrically connected satisfactorily regardless of the distance between the electrodes between the connection electrode 20a and the aluminum electrode 53.
Further, even when the distance between the electrodes needs to be large, the assembly can be easily performed.

  Moreover, since the metal layer 11 can employ an inexpensive material compared to the conductive resin layers 12a and 12b, the amount of the expensive conductive resin layers 12a and 12b can be suppressed, and the solar cell The manufacturing cost of the module 50 can be reduced.

  Moreover, the joining of the joining material 10, the connection electrode 20 a, and the aluminum electrode 53 can be performed simultaneously with the laminating process for forming the solar cell module 50. For this reason, compared with the case where the process of joining the bonding | jointing material 10, the connection electrode 20a, and the aluminum electrode 53 is provided separately, working efficiency can improve and the number of processes can also be reduced.

Further, since the bonding material 10 can be transferred from the release sheet 14 of the bonding material transfer sheet 13 and arranged on the connection electrode 20a, the arrangement work is facilitated.
In particular, in this embodiment, since the bonding material 10 is arranged in an arrangement pattern that is line-symmetric with the arrangement pattern of the connection electrodes 20 a, the unit group U of the bonding material transfer sheet 13 with respect to one solar battery cell 20. After the alignment, the bonding material 10 corresponding to each connection electrode 20a can be collectively transferred. Thereby, the efficiency of arrangement | positioning work can further be improved.

[First Modification]
Next, a modified example (first modified example) of the present embodiment will be described.
FIG. 9 is a schematic cross-sectional view showing the configuration of the solar cell bonding material assembly used in the solar cell module of the modified example (first modified example) of the first embodiment of the present invention.

As shown in FIG. 1, the solar cell module 60 of the present modification includes a bonding material 70 (a solar cell bonding material) instead of the bonding material 10 of the solar cell module 50 of the first embodiment.
Hereinafter, a description will be given centering on differences from the first embodiment.

As shown in FIG. 9, the bonding material 70 has a protrusion 11 c of the metal layer 11 provided on the outer peripheral portion of the second end surface 11 b instead of the metal layer 11 of the bonding material 10 of the first embodiment. Only the different metal layer 71 (joining material main body) is provided.
FIG. 9 shows an example where the height h 11c of the protrusion _11c is lower than the thickness t _{12b of the} conductive resin layer 12b. In this case, the protrusion 11c is buried in the layer thickness of the conductive resin layer 12b. Therefore, the bonding strength between the protrusion 11c and the conductive resin layer 12b with respect to the second end surface 11b is improved.
Further, similarly to the first embodiment, the thickness may be equal to or greater than the thickness of the conductive resin layer 12b. In this case, it is preferable that the amount of protrusion from the conductive resin layer 12b does not exceed the thickness of the connection electrode 20a.
Thus, when the protrusion part 11c protrudes from the conductive resin layer 12b, since the metal layer 61 and the connection electrode 20a are electrically connected even when the protrusion part 11c contacts the connection electrode 20a, the conductivity is further improved. It is possible.

The solar cell module 60 having such a configuration can be manufactured in the same manner as in the first embodiment except that the manufacturing method of the bonding material 70 is different.
In order to manufacture the bonding material 70 of this modification, as shown in FIG. 5A, a laminated body 73A in which the conductive resin layers 12a and 12b of the laminated body 13A of the first embodiment are replaced is formed. Then, a half cut similar to that in the first embodiment is performed (see FIGS. 5B and 5C) to form a laminated body 73 </ b> C in which the bonding material 70 is disposed on the release sheet 14. At this time, the protrusion 11c (not shown) protrudes toward the conductive resin layer 12b. Further, the uppermost surface of the laminate 73A is composed of the conductive resin layer 12a.
Then, another release sheet 14 (not shown) is prepared, the conductive resin layer 12a of the laminate 73A is brought into close contact with the other release sheet 14, and each bonding material 70 is transferred from the laminate 73A to the other release sheet 14. Thus, the bonding material transfer sheet 73 shown in FIG. 9 is manufactured.

[Second Embodiment]
Next, the solar cell module of the 2nd Embodiment of this invention is demonstrated.
FIG. 10 is a schematic cross-sectional view showing the configuration of the solar cell module according to the second embodiment of the present invention.

As shown in FIG. 10, the solar cell module 80 of the present embodiment is obtained by adding a black solder resist 81 to the solar cell module 50 of the first embodiment.
Hereinafter, a description will be given centering on differences from the first embodiment.

The solder resist 81 of the present embodiment covers the gaps between the aluminum electrodes 53 and both ends in the width direction on the aluminum electrode 53 so that the surface of the aluminum electrode 53 cannot be visually recognized from the translucent substrate 40 side. In addition, it is painted black. Thereby, the recessed hole part 87 is formed in the position which can oppose the connection electrode 20a of the photovoltaic cell 20, and the aluminum electrode 53 is partially exposed to the hole bottom of the recessed hole part 87. FIG.
In the present embodiment, the recessed hole portion 87 is provided in a circular hole shape of w _{87 having} a larger diameter than the diameter w ₁₀ of the bonding material 10 as an example. Thus, in plan view, and is exposed aluminum electrode 53 the size of the diameter w _87.
However, the shape and size of the recessed hole portion 87 are not limited to this as long as the aluminum electrode 53 having a size capable of arranging the bonding material 10 is exposed. For example, it may be provided in a polygonal hole shape such as a square hole, or may be a linear concave hole portion extending along the length direction of the comb-like portions 53A and 53B of the aluminum electrode 53.

  The solar cell module 80 having such a configuration is manufactured in the same manner as in the first embodiment except that the solder resist 81 is formed after the aluminum electrode 53 is formed on the substrate portion 55. Can do.

  According to the solar cell module 80 of the present embodiment, since the solder resist 81 is provided, it is necessary to make the inter-electrode distance between the connection electrode 20a and the aluminum electrode 53 larger than that in the first embodiment. However, since the bonding material 10 that allows good electrical connection even when the thickness is changed is used, the electrodes are connected well as in the first embodiment even if it is necessary to increase the distance between the electrodes. And the work efficiency at the time of connection can be improved.

  In the description of each of the above embodiments and the first modification, an example in which the aluminum electrode 53 is formed with a comb-like wiring pattern having an elongated linear portion has been described. In addition, for example, by attaching another metal foil such as a copper foil, a wiring electrode for connecting the bonding material 10 is formed in a region narrower than the aluminum electrode 53 at a position facing the connection electrode 20a. Also good.

  In the description of each of the above embodiments and the first modification, the example in which the aluminum electrode 53 is used as the wiring electrode has been described. However, the material of the wiring electrode is not limited to aluminum or aluminum alloy. For example, copper, a copper alloy, iron, an iron alloy, nickel, a nickel alloy, or the like can be used.

  In the description of each of the above embodiments and the first modification, the example in which the connection electrode 20a is circular in plan view has been described. However, this is an example, and the shape of the connection electrode 20a is not limited thereto. For example, an appropriate shape such as a polygon such as a quadrangle, an ellipse, a band, or a line can be employed.

  Moreover, in description of each said embodiment and a 1st modification, it is an example in the case of manufacturing the solar cell module by transferring the bonding material 10 from the bonding material transfer sheet 13 to the connection electrode 20a of the solar battery cell 20. As described above, the bonding material transfer sheet is formed by inverting the bonding material 10 in the thickness direction on the release sheet 14, and the bonding material 10 is transferred onto the aluminum electrode 53 from the bonding material transfer sheet. May be.

In the description of each of the embodiments and the first modification, the bonding material on the bonding material transfer sheet is an example in which the bonding material on the bonding material transfer sheet is arranged in a unit group in a line-symmetric arrangement pattern with respect to the arrangement pattern of the connection electrodes 20a. However, the arrangement pattern of the bonding material on the bonding material transfer sheet is not limited to this.
For example, the arrangement pattern of the bonding material on the bonding material transfer sheet may be a line-symmetric arrangement pattern with a part of the arrangement pattern of the connection electrode 20a.
In this case, a unit group corresponding to a part of the arrangement pattern of the connection electrodes 20a is formed on the release sheet. In this case, a plurality of bonding materials can be transferred to the connection electrode 20a or the aluminum electrode 53 for each unit group.
Further, for example, the arrangement pattern of the bonding material on the bonding material transfer sheet may be an arrangement pattern that is line-symmetric with the arrangement pattern of the connection electrodes 20 a of the plurality of solar cells 20.
In this case, a unit group corresponding to the arrangement pattern of the connection electrodes 20a of the plurality of solar cells 20 is formed on the release sheet. In this case, a plurality of bonding materials can be transferred to the connection electrode 20a or the aluminum electrode 53 for each unit group. That is, since the bonding material for bonding the plurality of solar cells 20 can be transferred at a time, the working efficiency is further improved.
For example, it may be unrelated to the arrangement pattern of the connection electrodes 20a. Specifically, for example, they may be arranged in a rectangular lattice with an appropriate pitch, or may be arranged in a line in the length direction of the release sheet 14.
In such a case, when the bonding material is transferred from the bonding material transfer sheet to the connection electrode 20a or the aluminum electrode 53, the bonding material can be moved and arranged one by one. As a result, even when the arrangement pattern of the connection electrodes 20a is different, the bonding material transfer sheet can be used for general purposes.

Further, in the description of each of the above embodiments and the first modification, when transferring the bonding material to the connection electrode 20a, the bonding strength is such that the bonding material does not fall off during the transportation of the solar battery cell 20, and the conductive property. Although it has been described that the particles may not be electrically connected to the connection electrode 20a, when the bonding material is transferred from the bonding material transfer sheet to the electrode, the adhesive strength and electric connection necessary for the solar cell module are completed. It may be transferred so that
The two conductive resin layers are made of different materials, and the conductive resin layer on the side first transferred from the bonding material transfer sheet is bonded to the electrode under the heating and pressurizing conditions for forming the solar cell module. When the strength and electrical connection are insufficient, transfer may be performed so that the adhesive strength and electrical connection are sufficient when transferring from the bonding material transfer sheet. Thereby, it is not necessary to change the heating condition and the pressurizing condition of the laminating process according to the processing conditions of the conductive resin layer to be transferred first, so that the heat load and pressing load in the laminating process can be reduced. .

  In the description of each of the embodiments and the first modification, the example in which the release sheet 14 is detachably attached to the conductive resin layer 12a has been described. However, the release sheet 14 is detachably attached to the conductive resin layer 12b. Or may be in close contact with both conductive resin layers 12a and 12b so as to be peelable.

In the description of each of the embodiments and the first modification, the solar cell bonding material has been described as an example in which the bonding material main body includes the first conductive resin layer and the second conductive resin layer. However, when an electrical connection can be easily made without using a conductive resin layer, such as when an oxide film is not formed on the electrode, at least one of the first conductive resin layer and the second conductive resin layer, A conductive connecting material other than the conductive resin layer may be substituted.
An example of such a conductive connection material is a solder layer. Such a conductive connection material is more preferably a material that can be joined to an electrode by heating or pressurization in a laminating process when manufacturing a solar cell module.
For example, a configuration in which a conductive resin layer is used on the side to be bonded to the release sheet and a conductive connection material different from the conductive resin layer is provided on the opposite side as the solar cell bonding material assembly is also suitable. .

  Moreover, all the components described above can be implemented by appropriately changing or deleting the combination within the scope of the technical idea of the present invention.

  Next, specific examples 1 to 3 of the solar cell bonding material, the solar cell bonding material assembly, and the solar cell module of the first embodiment will be described together with comparative examples.

[Example 1]
As the metal layer 11 of the bonding material 10 of this example, an aluminum plate made of high-purity aluminum (purity 99% or more) having a thickness of 300 μm was used.
As the conductive resin layer 12a and the release sheet 14, SP100 (trade name) manufactured by Sony Chemical & Information Device Co., Ltd. was used. The conductive resin layer in SP100 is obtained by dispersing nickel particles as conductive particles in an epoxy thermosetting resin binder.
As the conductive resin layer 12b, a conductive resin layer of SP100 was transferred and used.
The manufacturing method of the bonding material transfer sheet 13 was the same as that described with reference to FIGS. 5A, 5B, and 5C. For this reason, the protrusion part 11c which faced the peeling sheet 14 side was formed. The maximum height of the protrusion 11c was h _11c = 10 (μm).
The shape of the bonding material 10 in plan view is a circle of w ₁₀ = 3 (mm). The conductive resin layer 12b of the bonding material transfer sheet 13 is connected to the solar battery cells 20 as shown in FIG. 6B. The electrode 20a was heated and pressed and temporarily bonded to the connection electrode 20a to form the solar cell 21 with the bonding material. In this temporary bonding step, pressurization was performed for 1 second at a temperature of 80 ° C. and a pressure of 0.2 MPa.
At this time, since the bonding material 10 is temporarily bonded to each connection electrode 20a at a time, temporary bonding can be performed more quickly than in the case where the bonding material 10 is sequentially bonded to each connection electrode 20a.
The solar cell module 50 of the present embodiment includes a substrate portion 55 on which an aluminum electrode 53 is formed in accordance with the arrangement of the connection electrodes 20a of the solar cells 20, the lower sealing material film 32, the solar cell 21 with bonding material, the upper side. A sealing material film 31 and a translucent substrate 40 made of a glass plate having a thickness of 3 mm were laminated in this order, and the laminate was produced by module lamination using a module laminator.
Here, the lower sealing material film 32 was a 300-μm-thick black EVA film, and the upper sealing material film 31 was a 300-μm-thick transparent EVA film.
The module lamination was carried out in vacuum at 150 ° C. for 3 minutes, followed by pressurization in the laminating direction at 150 ° C. and atmospheric pressure for 12 minutes.
In the solar cell module 50 manufactured in this way, the solar cells 20 were well electrically connected to the aluminum electrode 53, and no conduction failure occurred.

[Example 2]
The present embodiment is different from the bonding material transfer sheet 13 of the first embodiment in that the metal layer 11 is processed so as not to be burred by water jet processing, whereas the bonding material transfer sheet 13 is formed by punching processing.
In the solar cell module 50 manufactured using the bonding material transfer sheet 13 of this example, the solar cell 20 is well electrically connected to the aluminum electrode 53 in the same manner as in Example 1 above. I did not.

[Example 3]
The present embodiment is different from the embodiment 1 in that the bonding material 10 of the bonding material transfer sheet 13 of the first embodiment was punched into a 3 mm square.
In the solar cell module 50 manufactured using the bonding material transfer sheet 13 of this example, the solar cell 20 is well electrically connected to the aluminum electrode 53 in the same manner as in Example 1 above. I didn't.

[Comparative example]
This comparative example uses Pertron (registered trademark) S-3031 (trade name; manufactured by Pernox Co., Ltd.), which is a silver paste, in place of the bonding material 10 in the solar cell module 50 of Example 1 described above. .
In such a solar cell module, after the substrate portion 55 is formed, a silver paste is applied to the connection electrode 20a by a screen printing method, and then the substrate portion 55, the lower sealing material film 32, the solar cell 20, The sealing material film 31 and the translucent substrate 40 were laminated in this order, and were produced by module lamination using a module laminator.
In this comparative example, since application time of Pertron (registered trademark) S-3031 required about 3 seconds for one place, it was much longer than the temporary bonding work of the bonding material 10 in Examples 1 to 3 above. It took work time.

10, 70 Bonding material (bonding material for solar cells)
11, 61 Metal layer (joint body)
11a 1st end surface 11b 2nd end surface 11c Protrusion part 12a Conductive resin layer (1st conductive resin layer)
12b Conductive resin layer (second conductive resin layer)
13, 73 Bonding material transfer sheet (solar cell bonding material assembly)
14 Release sheet 14c, 14d Identification mark 20 Solar cell 20a Connection electrode 20b Light receiving surface 20c Back surface (back surface portion)
30 Sealant 40 Translucent Substrate 50, 60, 80 Solar Cell Module 51 Base Material (Substrate for Wiring)
52 Insulating adhesive layer 53 Aluminum electrode (wiring electrode)
54 Back sheet 55 Substrate part 81 Solder resist U Unit group

Claims (8)

The connection electrode of the solar battery cell provided on the back surface opposite to the light receiving surface of the solar battery cell is joined to the wiring electrode on the wiring board, and the connection electrode and the wiring electrode are electrically connected to each other. A solar cell bonding material,
A metal bonding material body having a first end face in one of the thickness directions and a second end face located on the opposite side of the thickness direction with respect to the first end face;
A first conductive resin layer formed on the first end surface of the bonding material body;
A second conductive resin layer formed on the second end surface of the bonding material body;
A solar cell bonding material comprising: The bonding material body protrudes from the first end surface toward the first conductive resin layer at the outer peripheral portion of the first end surface, or from the second end surface at the outer peripheral portion of the second end surface. 2. The solar cell bonding material according to claim 1, further comprising a protruding portion that protrudes toward the second conductive resin layer. The said joining material main body consists of aluminum or an aluminum alloy, The joining material for solar cells of Claim 1 or 2 characterized by the above-mentioned. A plurality of solar cell bonding materials according to any one of claims 1 to 3,
A release sheet that is detachably adhered to at least one of the first conductive resin layer and the second conductive resin layer of the plurality of solar cell bonding materials,
The plurality of solar cell bonding materials include:
A solar cell bonding material assembly disposed to be separated from each other along the sheet surface direction of the release sheet. The plurality of solar cell bonding materials include:
The solar cell bonding material assembly according to claim 4, wherein the solar cell bonding material assembly is arranged in an arrangement pattern that is line-symmetric with the arrangement pattern of the connection electrodes of the solar cells on the release sheet. The solar cell bonding material assembly according to claim 4, wherein the release sheet has an identification mark for identifying a position of the solar cell bonding material. A solar cell provided with a connection electrode on the back surface opposite to the light receiving surface;
A wiring board having wiring electrodes;
The solar cell bonding material according to any one of claims 1 to 3,
With
The solar cell module in which the connection electrode of the solar battery cell and the wiring electrode on the wiring substrate are electrically connected by the solar cell bonding material. The solar cell bonding material of the solar cell bonding material assembly according to any one of claims 4 to 6, wherein one of the connection electrode of the solar battery cell and the wiring electrode on the wiring substrate is provided. Two conductive resin layers are stacked and bonded, and then the release sheet is peeled off to transfer the solar cell bonding material to one of the connection electrode and the wiring electrode,
A solar cell module manufactured by overlapping and joining the first conductive resin layer of the solar cell bonding material with the other of the connection electrode and the wiring electrode.

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