JP7514233B2 - Solar Cell Module - Google Patents

Description

The present invention relates to a solar cell module.

Conventionally, in a crystalline solar cell module, a plurality of solar cells are electrically connected via wiring members. For example, in the solar cell module of Patent Document 1, a bus bar electrode portion and a finger electrode portion are provided as collector electrodes on both sides of each solar cell, and ends of wiring members are soldered to the bus bar electrode portions to connect the solar cells to each other.

International Publication No. 2017/179317

Incidentally, in conventional solar cell modules, solar cells are sandwiched between EVA sheets, and the outside of the EVA sheets is further sandwiched between base materials such as a glass substrate or a back sheet to seal the cells.
If an initial defect or the like occurs during the manufacture of a solar cell module, the substrate and EVA sheet are peeled off and the module is disassembled to identify the cause of the defect.
However, in conventional solar cell modules, when the substrate and the EVA sheet are peeled off, the adhesive strength between the busbar electrode portion, which is a part of the collector electrode, and the underlayer that is the underlayer for the busbar electrode portion is smaller than the adhesive strength between the busbar electrode portion and the EVA sheet. Therefore, when the substrate and the EVA sheet are peeled off, the busbar electrode portion may be pulled by the EVA sheet and peeled off from the underlayer. If the busbar electrode portion peels off from the underlayer, it is not possible to inspect for electrical continuity, etc., and there is a problem that the cause of defects, such as initial defects, cannot be identified.

Therefore, an object of the present invention is to provide a solar cell module in which the bus bar electrode portion is less likely to peel off when the base material and the sealing material are peeled off, compared to conventional solar cell modules.

One aspect of the present invention for solving the above-mentioned problems is a solar cell module in which a solar cell and a wiring member are arranged between two base materials, and the space between the two base materials is filled with a sealing material, wherein the solar cell has a front electrode layer, a back electrode layer, and a photoelectric conversion unit sandwiched between the front electrode layer and the back electrode layer, and a bus bar electrode portion is provided on at least one of the electrode layers of the front electrode layer and the back electrode layer, and the wiring member is bonded to the bus bar electrode portion via a solder layer, the solar cell has an interfacial peeling layer that covers at least a part of a side surface of the bus bar electrode portion when the solar cell is viewed in cross section, and further extends across the one of the electrode layers, and an adhesive strength at the interface between the bus bar electrode portion and the interfacial peeling layer is greater than an adhesive strength at the interface between the sealing material and the interfacial peeling layer, and an adhesive strength at the interface between the sealing material and the interfacial peeling layer is greater than an adhesive strength at the interface between the one of the electrode layers and the interfacial peeling layer.

According to this aspect, the adhesive strength at the interface between the busbar electrode portion and the interfacial peeling layer is greater than the adhesive strength at the interface between the sealing material and the interfacial peeling layer. Therefore, when the substrate and sealing material are peeled off, the interfacial peeling layer is pulled by the sealing material and self-destructs, resulting in partial peeling, or the interface between the sealing material and the interfacial peeling layer peels off preferentially compared to the interface between the busbar electrode portion and the interfacial peeling layer.
Furthermore, according to this aspect, the adhesive strength at the interface between the sealing material and the interfacial peeling layer is greater than the adhesive strength at the interface between one of the electrode layers and the interfacial peeling layer, so that when the substrate and sealing material are peeled off, the interface between one of the electrode layers and the interfacial peeling layer peels off preferentially compared to the interface between the sealing material and the interfacial peeling layer.
That is, according to this aspect, when the substrate and the sealing material are peeled off, in a portion of the interfacial peeling layer extending from the side surface of the busbar electrode portion to one of the electrode layers, peeling occurs at the interface between the interfacial peeling layer and one of the electrode layers, and on the busbar electrode portion, peeling occurs at the interface between the busbar electrode portion and the interfacial peeling layer. Therefore, the substrate and the sealing material can be peeled off without the busbar electrode portion peeling off from the one of the electrode portions. As a result, breakage of the busbar electrode portion due to being pulled by the sealing material is unlikely to occur, and evaluation for initial defects and the like can be performed with the substrate and the sealing material peeled off.

In a preferred aspect, the interfacial peeling layer extends on the one electrode layer from a side surface of the bus bar electrode portion to an area that is 0.5 times or more the width of the bus bar electrode portion.

In a more preferred aspect, the interfacial peeling layer extends from a side surface of the bus bar electrode portion on the one electrode layer to an area that is 1.5 times or more the width of the bus bar electrode portion.

In a preferred aspect, the one electrode layer is formed of a transparent conductive oxide.

In a preferred aspect, the interface release layer is a flux layer containing a rosin compound, and the halide content of the flux component is 0.5 wt % or less.

According to this aspect, the interface peeling layer is formed of a flux having a grade of A or AA according to JIS Z 3283:2006 and a medium or low activity, so that corrosion of one of the electrode layers that serves as the base can be suppressed or prevented.

In a preferred aspect, the busbar electrode portion is wider than the solder layer, and the interfacial peeling layer covers the exposed portion of the busbar electrode portion from the solder layer when the solar cell is viewed in cross section.

According to this aspect, since the width of the busbar electrode portion is wider than the width of the solder layer, when the solder layer is formed, the solder remains at the busbar electrode portion and does not come into contact with one of the electrode layers. Therefore, the one of the electrode layers is less likely to become hot due to the formation of the solder layer.
According to this aspect, the interfacial peeling layer covers the exposed portion of the busbar electrode portion, so that the busbar electrode portion is less likely to peel off from one of the electrode layers, and when peeling off the substrate or sealing material, they can be easily peeled off leaving the busbar electrode portion behind.

In a preferred aspect, the battery module receives light from the front electrode layer side based on the photoelectric conversion section and generates electricity, the front electrode layer and the back electrode layer are provided with bus bar electrode portions, and the bus bar electrode portion of the back electrode layer is wider than the bus bar electrode portion of the front electrode layer.

According to this aspect, since the width of the back electrode layer is wider than the width of the front electrode layer on the light-receiving side, a sufficient area of the back electrode layer can be secured, and resistance loss in the back electrode layer can be suppressed.

In a preferred aspect, the sealing material includes a sealing sheet, and the bus bar electrode portion is formed of a thin film.

In conventional solar cell modules, when solar cells are sealed by sandwiching them between sealing sheets such as EVA sheets, they may appear to be tightly attached at first glance, but may not be sealed accurately. In such cases, when used for a long period of time, air, water, etc. get between the sealing sheet and its adhesive surface, creating voids and causing the sealing sheet to float.
When the busbar electrode portion is formed of a thin film as in this aspect, the rigidity of the busbar electrode portion itself is smaller than that when the busbar electrode portion is formed of a bulk material, and therefore, when the lifting of the encapsulating sheet spreads, the busbar electrode portion is pulled by the encapsulating sheet, causing a problem that cohesive failure occurs within the busbar electrode portion or the busbar electrode portion peels off from the underlying electrode layer.
Even in such a case, according to this aspect, the adhesive strength at the interface between the busbar electrode portion and the interfacial peeling layer is greater than the adhesive strength at the interface between the sealing material and the interfacial peeling layer, so that even if the sealing material floats, the interfacial peeling layer will undergo cohesive failure inside or will peel off at its interface with the sealing material before the interface between the busbar electrode portion and the interfacial peeling layer, thereby dissipating the force generated by the floating of the sealing material and preventing the busbar electrode portion from peeling off from the underlying electrode layer.

In a preferred aspect, the bus bar electrode portion remains on the one electrode layer when the sealing material is peeled off.

According to this aspect, the bus bar electrode portion does not peel off from one of the electrode layers, and reliability is high.

In a preferred aspect, a second interfacial peeling layer is interposed between the wiring member and the sealing material, and the adhesive strength between the wiring member and the bus bar electrode portion is greater than the adhesive strength between the second interfacial peeling layer and the sealing material.

According to this aspect, it is possible to prevent the wiring member from peeling off from the bus bar electrode portion toward the sealing material side.

One aspect of the present invention is a solar cell module in which a solar cell and a wiring member are arranged between two base materials and the space between the two base materials is filled with a sealing material, wherein the solar cell has a photoelectric conversion unit, a bus bar electrode unit is provided on the photoelectric conversion unit, the wiring member is adhered to the bus bar electrode unit via a solder layer, the solar cell has an interfacial peeling layer containing a rosin compound, the interfacial peeling layer covers at least a portion of a side surface of the bus bar electrode unit when the solar cell is viewed in cross section and further extends across the photoelectric conversion unit, the adhesive strength at the interface between the bus bar electrode unit and the interfacial peeling layer is greater than the adhesive strength at the interface between the sealing material and the interfacial peeling layer, and the adhesive strength at the interface between the sealing material and the interfacial peeling layer is greater than the adhesive strength at the interface between the photoelectric conversion unit and the interfacial peeling layer.

According to this aspect, the adhesive strength at the interface between the busbar electrode portion and the interfacial peeling layer is greater than the adhesive strength at the interface between the sealing material and the interfacial peeling layer. Therefore, when the substrate and sealing material are peeled off, the interface between the sealing material and the interfacial peeling layer peels off preferentially compared to the interface between the busbar electrode portion and the interfacial peeling layer.
According to this aspect, the adhesive strength at the interface between the sealing material and the interfacial peeling layer is greater than the adhesive strength at the interface between the photoelectric conversion section and the interfacial peeling layer, so that when the substrate and sealing material are peeled off, the interface between the photoelectric conversion section and the interfacial peeling layer peels off preferentially compared to the interface between the sealing material and the interfacial peeling layer.
That is, according to this aspect, when the base material is peeled off, in the portion extending from the side surface of the busbar electrode portion of the interfacial peeling layer to the photoelectric conversion portion, peeling occurs at the interface between the interfacial peeling layer and the photoelectric conversion portion, and on the busbar electrode portion, peeling occurs at the interface between the busbar electrode portion and the interfacial peeling layer, so that the base material can be peeled off without the busbar electrode portion peeling off from the photoelectric conversion portion. As a result, breakage of the busbar electrode portion due to being pulled by the sealing material is unlikely to occur, and evaluation for initial defects and the like can be performed with the base material and sealing material peeled off.

According to the solar cell module of the present invention, when the base material and the sealing material are peeled off, the bus bar electrode portion is less likely to peel off than in the conventional solar cell module.

1 is a perspective view that illustrates a solar cell module according to a first embodiment of the present invention; FIG. 2 is an exploded perspective view of the solar cell module of FIG. 1 . 2 is a cross-sectional view perpendicular to the extension direction of a first bus bar electrode portion of the solar cell module of FIG. 1 and taken at a position not passing through a first finger electrode portion. FIG. 2 is a cross-sectional view perpendicular to the extension direction of a first bus bar electrode portion of the solar cell module of FIG. 1 and taken at a position passing through a first finger electrode portion. FIG. 3 is a cross-sectional perspective view of the solar cell string of FIG. 2 as viewed from the front side. 3 is a cross-sectional perspective view of the solar cell string of FIG. 2 as viewed from the rear side. FIG. 3 is an exploded perspective view of the solar cell string of FIG. 2 . 8A and 8B are explanatory views of the solar cell of FIG. 7, in which FIG. 8A is a front view and FIG. 8B is a rear view. 2 is a cross-sectional perspective view showing the solar cell module immediately after a coating step in the manufacturing process of the solar cell module of FIG. 1 . FIG. 2A and 2B are cross-sectional views showing the condition of key parts on the front side when peeling off the substrate and sealing material from the solar cell module of FIG. 1, where (a) is a cross-section perpendicular to the extension direction of the first bus bar electrode portion of the solar cell module and shows the condition at a position that does not pass through the first finger electrode portion, and (b) is a cross-section perpendicular to the extension direction of the first bus bar electrode portion of the solar cell module and shows the condition at a position that passes through the first finger electrode portion. 2A and 2B are cross-sectional views showing the condition of key parts on the back side when peeling off the substrate and sealing material from the solar cell module of FIG. 1 , where (a) is a cross-section perpendicular to the extension direction of the first bus bar electrode portion of the solar cell module and shows the condition at a position that does not pass through the first finger electrode portion, and (b) is a cross-section perpendicular to the extension direction of the first bus bar electrode portion of the solar cell module and shows the condition at a position that passes through the first finger electrode portion. FIG. 11 is an explanatory diagram of a solar cell module according to a second embodiment of the present invention, showing a cross section perpendicular to the extension direction of a first bus bar electrode portion and at a position not passing through a first finger electrode portion. 13 is a cross-sectional view perpendicular to the extension direction of the first bus bar electrode portion of the solar cell module of FIG. 12 and taken at a position passing through the first finger electrode portion. FIG. FIG. 13 is a cross-sectional perspective view of the solar cell string of FIG. 12 as viewed from the front side. 13 is a cross-sectional perspective view showing the solar cell module immediately after a coating step in the manufacturing process of the solar cell module of FIG. 12. 13 is a cross-sectional view perpendicular to the extension direction of a first bus bar electrode portion of a solar cell module according to a third embodiment of the present invention, taken at a position not passing through a first finger electrode portion. FIG. 17A and 17B are cross-sectional views perpendicular to the extension direction of the first bus bar electrode portion of the solar cell module when the substrate and the sealing material are peeled off from the solar cell module in Figure 16, showing the situation at a position that does not pass through the first finger electrode portion, where (a) shows the front side and (b) shows the back side. 13 is a cross-sectional view perpendicular to the extension direction of a first bus bar electrode portion of a solar cell module according to a fourth embodiment of the present invention, taken at a position not passing through a first finger electrode portion. FIG.

Hereinafter, an embodiment of the present invention will be described in detail.

The solar cell module 1 according to the first embodiment of the present invention is a heterojunction type solar cell module.
As shown in Figs. 1 and 2, the solar cell module 1 includes a first substrate 2, a second substrate 3, a solar cell string 5, and sealing materials 6a and 6b.
The solar cell module 1 is a single-sided light-receiving solar cell module in which the outer main surface of the first substrate 2 forms the light-receiving surface, based on the photoelectric conversion unit 21 (see Figure 3) of the solar cell string 5, and light is received from the first substrate 2 side to generate electricity in the solar cell string 5.

The first base material 2 is a plate-like or film-like member having a planar extension, and in this embodiment is a transparent insulating substrate having light-transmitting and insulating properties.
The first base material 2 is not particularly limited as long as it has light-transmitting and insulating properties, and for example, a glass substrate or a transparent resin substrate can be used.

The second base material 3 is a plate-like or film-like member having a planar extension, and in this embodiment is an insulating sheet having insulating properties.
The second base material 3 is not particularly limited as long as it has insulating properties, and for example, a glass substrate, a resin sheet, or the like can be used.

As shown in FIGS. 2 to 4, the solar cell string 5 includes a plurality of solar cells 10, wiring members 11 that connect the solar cells 10 together, and solder layers 12, 13 that connect the solar cells 10 and the wiring members 11.

The solar cell 10 is a crystalline type solar cell, and includes a front electrode layer 20, a photoelectric conversion section 21, and a back electrode layer 22, as shown in Figures 3 and 4. In the solar cell 10, a first collector 25 and a first interface peeling layer 26 are provided on the front electrode layer 20, and a second collector 35 and a second interface peeling layer 36 are provided on the back electrode layer 22.

The front electrode layer 20 is a transparent conductive layer that is translucent and conductive.
The front electrode layer 20 of this embodiment is made of a transparent conductive oxide such as indium tin oxide (ITO) or zinc oxide.

The photoelectric conversion unit 21 has a PN junction, and a semiconductor layer is formed on a semiconductor substrate. Specifically, the solar cell 10 is a crystalline silicon solar cell, and has a one-conductivity type silicon substrate as a support substrate, and a reverse conductivity type silicon layer or the like formed on the one-conductivity type silicon substrate. The "one-conductivity type" refers to one of the conductivity types, n-type or p-type, and the "reverse conductivity type" refers to a conductivity type opposite to the "one-conductivity type". In other words, when the "one-conductivity type" is n-type, the "reverse conductivity type" is p-type, and when the "one-conductivity type" is p-type, the "reverse conductivity type" is n-type.

The back electrode layer 22, like the front electrode layer 20, is a transparent conductive layer that is translucent and conductive.
The back electrode layer 22 in this embodiment is made of a transparent conductive oxide such as indium tin oxide (ITO) or zinc oxide.

The first collector electrode 25 is a comb-shaped electrode that extracts electricity from the front electrode layer 20, and is a thin-film electrode.
The first collector electrode 25 is not particularly limited as long as it has a higher conductivity than the front electrode layer 20, and for example, metals such as gold, silver, copper, and palladium, or metal alloys can be used.
The method for forming the first collector 25 is not particularly limited, and the first collector 25 can be formed by, for example, a printing method, a plating method, or a vapor phase film formation method. Among these, the first collector 25 is preferably formed by a printing method or a vapor phase film formation method from the viewpoint of reducing costs, and more preferably formed by a printing method from the viewpoint of exerting a more effective effect. Examples of the vapor phase film formation method include a CVD method and a sputtering method.

As shown in FIG. 8A , the first collector 25 is composed of a first bus bar electrode portion 40 and a first finger electrode portion 41 .
The first bus bar electrode portion 40 is a conductive portion extending on the front electrode layer 20 in a predetermined direction (hereinafter also referred to as the vertical direction Y).
A width W1 of the first busbar electrode portion 40 shown in FIG. 8A is larger than a width W2 of the first finger electrode portion 41 and is at least twice the width W2 of the first finger electrode portion 41.
The width W1 of the first bus bar electrode portion 40 is preferably 0.5 mm or more and 3 mm or less.

5 , the first finger electrode portion 41 is a conductive portion extending on the front electrode layer 20 from the first bus bar electrode portion 40 perpendicular to the first bus bar electrode portion 40. That is, the first finger electrode portion 41 extends in the lateral direction X.

The first interface peeling layer 26 is an organic compound layer having translucency and containing a rosin compound as a main component, and is a flux layer formed by hardening the flux 70. The "main component" here means that the proportion of the flux 70 in all components is 50% or more.
The first interface release layer 26 is made of a flux of grade AA or A in accordance with JIS Z 3283:2006, and the halide content of the flux component is preferably 0.5 wt % or less.
The flux 70 preferably contains a rosin compound and an activator.

The second collector electrode 35 is a comb-shaped electrode that extracts electricity from the rear electrode layer 22, and is a thin-film electrode.
The second collector electrode 35 is not particularly limited as long as it has a higher conductivity than the back electrode layer 22, and for example, metals such as gold, silver, copper, and palladium, and metal alloys can be used.
The method for forming the second collector 35 is not particularly limited, and the second collector 35 can be formed by, for example, a printing method, a plating method, or a vapor phase method. Among these, the second collector 35 is preferably formed by a printing method or a vapor phase method from the viewpoint of reducing costs, and more preferably formed by a printing method from the viewpoint of exerting a more effective effect. Examples of the vapor phase film formation method include a CVD method and a sputtering method.

As shown in FIG. 8B , the second collector electrode 35 is composed of a second bus bar electrode portion 50 and a second finger electrode portion 51 .
The second bus bar electrode portion 50 is a conductive portion extending in the vertical direction Y on the back electrode layer 22 .
A width W3 of the second busbar electrode portion 50 shown in FIG. 8( b ) is greater than a width W4 of the second finger electrode portion 51 and is four or more times the width W4 of the second finger electrode portion 51 .
The width W3 of the second bus bar electrode portion 50 is preferably 1 mm or more and 3 mm or less.

6 , the second finger electrode portion 51 is a conductive portion extending on the back electrode layer 22 from the second bus bar electrode portion 50 perpendicular to the second bus bar electrode portion 50. That is, the second finger electrode portion 51 extends in the lateral direction X.

The second interface peeling layer 36 is an organic compound layer that has light transmitting properties and contains a rosin compound as a main component, and is a flux layer formed by hardening the flux 70 .
The second interface release layer 36 of this embodiment, like the first interface release layer 26, is composed of a flux of grade AA or A in accordance with JIS Z 3283:2006, and it is preferable that the halide content of the flux component is 0.5 wt % or less.

The wiring member 11 is a so-called interconnector, and as shown in FIG. 7, is an elongated member having a certain thickness and extending in a predetermined direction.
As shown in the enlarged view of FIG. 7, the wiring member 11 is a conductor having solder 71 formed on its surface, and the solder 71 is formed on the outer surface of a conductive core material 72 .
The thickness of the wiring member 11 is thicker than the thickness of the collector electrodes 25 and 35 which are thin films, and is therefore less likely to bend.
As shown in FIG. 7 , the wiring member 11 includes connector portions 60 and 61 and a connection portion 62 .
The connector portions 60 , 61 are portions that can be connected to the bus bar electrode portions 40 , 50 of the solar cell 10 .
The connection portion 62 is a portion that connects the first connector portion 60 and the second connector portion 61 .

The solder layers 12, 13 are adhesive layers that physically and electrically connect the bus bar electrode portions 40, 50 and the connector portions 60, 61 of the wiring member 11 as shown in FIGS.
The solder layers 12 and 13 are layers in which the solder 71 (see FIG. 7) is hardened, and are conductive layers having electrical conductivity. The solder layers 12 and 13, like the interfacial peeling layers 26 and 36, contain a rosin compound component.

The sealing materials 6a and 6b are adhesive members that seal the solar cell string 5 disposed between the two base materials 2 and 3, as shown in FIG. 3, and bond the two base materials 2 and 3 together.
The sealing materials 6a and 6b are sheet-shaped sealing sheets, and for example, sealing sheets of EVA, polyolefin, ionomer, etc. can be used.

Next, the positional relationship between the components of the solar cell module 1 of the first embodiment will be described.

2, the solar cell module 1 has a solar cell string 5 sandwiched between sheet-like sealing materials 6a, 6b, and further sandwiched between two base materials 2, 3 on the outside of the sealing materials 6a, 6b. That is, in the solar cell module 1, the solar cell string 5 is disposed between the base materials 2, 3, and the sealing materials 6a, 6b are filled between the base materials 2, 3.
As shown in Figures 5 and 7, the wiring member 11 has a first connector portion 60 connected to the first bus bar electrode portion 40 of one of the two adjacent solar cell 10a, 10b to be connected via a first solder layer 12, and as shown in Figures 6 and 7, the second connector portion 61 connected to the second bus bar electrode portion 50 of the other solar cell 10b via a second solder layer 13.
The width W1 of the first busbar electrode portion 40 is narrower than the width W3 of the second busbar electrode portion 50 when viewed in a cross section perpendicular to the extension direction of the first busbar electrode portion 40, as shown in Figures 3 and 8.

As shown in Fig. 4, the first interface peeling layer 26 is in contact with both end faces (width direction end faces) of the first solder layer 12 when viewed in a cross section perpendicular to the extension direction of the first bus bar electrode portion 40. Also, as shown in Fig. 3, the first interface peeling layer 26 spreads from both sides of the first solder layer 12 in a cross section that does not pass through the first finger electrode portion 41, passes through the end faces in the width direction (lateral direction X) of the first bus bar electrode portion 40, and extends onto the front electrode layer 20.
That is, as shown in FIG. 5 , the first interface peeling layer 26 is formed so as to spread over the front electrode layer 20 and sandwich the first bus bar electrode portion 40 in the lateral direction X, and covers the exposed portion of the first bus bar electrode portion 40 from the first solder layer 12.

As shown in Figure 4, in a cross section passing through the first finger electrode portion 41, both ends of the first busbar electrode portion 40 in the horizontal direction X are covered with the first interface peeling layer 26, and the first finger electrode portion 41 has a portion that is covered with the first interface peeling layer 26 and a portion that is not covered with the first interface peeling layer 26.
Furthermore, the first interface peeling layer 26 extends parallel to the first bus bar electrode portion 40 and extends across the multiple first finger electrode portions 41 in the longitudinal direction Y, as shown in FIG.

The extension length D1 of the first interface peeling layer 26 from the first solder layer 12 shown in FIG. 3 is preferably 0.25 mm or more and 10 mm or less.
The extension length D1 is preferably 0.5 times or more, more preferably 1 time or more, and particularly preferably 1.5 times or more, the width W1 of the first busbar electrode portion 40 shown in Fig. 8(a) . The extension length D1 is preferably 10 times or less, and more preferably 5 times or more, the width W1 of the first busbar electrode portion 40.

As shown in Figs. 3 and 6, the second bus bar electrode portion 50 is wider than the width of the second solder layer 13 and has protruding portions 52, 53 protruding from both sides of the second solder layer 13 in the width direction (lateral direction X).
When viewed in cross section perpendicular to the extension direction of the second busbar electrode portion 50, as in Figures 3 and 4, the second interface peeling layer 36 is in contact with both end faces of the second solder layer 13 in the width direction (lateral direction X).
3 , in a cross section not passing through the second finger electrode portion 51, the second interface peeling layer 36 spreads from both sides of the second solder layer 13, passes over the protruding portions 52 and 53 of the second busbar electrode portion 50, covers the end face of the second busbar electrode portion 50, and further extends onto the back-side electrode layer 22. That is, the second interface peeling layer 36 is formed so as to sandwich the second busbar electrode portion 50 as shown in FIG.

4 , the second interface peeling layer 36 extends from above the second bus bar electrode portion 50 across a portion of the second finger electrode portion 51. That is, in the cross section passing through the second finger electrode portion 51, both ends of the second bus bar electrode portion 50 in the lateral direction X are covered with the second interface peeling layer 36, and the second finger electrode portion 51 has a portion that is covered with the second interface peeling layer 36 and a portion that is not covered with the second interface peeling layer 36.
As shown in FIG. 6 , the second interface peeling layer 36 extends parallel to the second bus bar electrode portion 50 and extends across the multiple second finger electrode portions 51 in the longitudinal direction Y.

The extension length D2 from the second solder layer 13 of the second interface peeling layer 36 shown in Figure 3 is approximately the same as the extension length D1 from the first solder layer 12 of the first interface peeling layer 26, and is preferably 0.25 mm or more and 10 mm or less.
The extension length D2 is preferably 0.5 times or more, more preferably 1 time or more, and particularly preferably 1.5 times or more, the width W3 of the second busbar electrode portion 50 shown in Fig. 8(b) . The extension length D2 is preferably 10 times or less, and more preferably 5 times or more, the width W3 of the second busbar electrode portion 50.
The extension length D3 from the protrusions 52, 53 of the second interface peeling layer 36 is not particularly limited, but is preferably equal to or less than the extension length D2 from the second solder layer 13, and is preferably less than the extension length D2 from the second solder layer 13.

Here, the relationship between the adhesive strength of the bus bar electrode portions 40, 50, the interfacial peeling layers 26, 36, and the sealing materials 6a, 6b will be described.

3 is greater than the adhesive strength at the interface between the sealing material 6a and the first interface peeling layer 26, which in turn is greater than the adhesive strength at the interface between the front electrode layer 20 and the first interface peeling layer 26. In other words, the interface between the first busbar electrode portion 40 and the first interface peeling layer 26 is more difficult to peel off than the interface between the sealing material 6a and the first interface peeling layer 26, and the interface between the sealing material 6a and the first interface peeling layer 26 is more difficult to peel off than the interface between the front electrode layer 20 and the first interface peeling layer 26.

Similarly, the adhesive strength at the interface between the second busbar electrode portion 50 and the second interfacial peeling layer 36 is greater than the adhesive strength at the interface between the sealing material 6b and the second interfacial peeling layer 36, and the adhesive strength at the interface between the sealing material 6b and the second interfacial peeling layer 36 is greater than the adhesive strength at the interface between the back electrode layer 22 and the second interfacial peeling layer 36. In other words, the interface between the second busbar electrode portion 50 and the second interfacial peeling layer 36 is more difficult to peel off than the interface between the sealing material 6b and the second interfacial peeling layer 36, and the interface between the sealing material 6b and the second interfacial peeling layer 36 is more difficult to peel off than the interface between the back electrode layer 22 and the second interfacial peeling layer 36.

Next, a method for manufacturing the solar cell module 1 of the first embodiment will be described.

First, as in conventional solar cells, a photoelectric conversion section 21 is formed, electrode layers 20, 22 are formed on each main surface of the photoelectric conversion section 21, and collector electrodes 25, 35 are further formed on the electrode layers 20, 22 to form the solar cell 10 (collector electrode formation process).

Subsequently, as shown in FIG. 9, flux 70, which is a raw material of the interface peeling layers 26, 36 having fluidity, is applied to the bus bar electrode portions 40, 50 of the solar cell 10 (application step).
Specifically, on the front side of the solar cell 10, the coating is applied intentionally overflowing from above the first busbar electrode portion 40 so as to straddle from above the first busbar electrode portion 40 onto the front-side electrode layer 20 and the first finger electrode portion 41. Similarly, on the back side of the solar cell 10, the coating is applied intentionally overflowing from above the busbar electrode portion 50 so as to straddle from above the second busbar electrode portion 50 onto the back-side electrode layer 22 and the second finger electrode portion 51.
At this time, the flux 70 is applied from the side surfaces of the busbar electrode portions 40, 50 onto the electrode layers 20, 22 to an area that is 0.5 times or more the widths W1, W3 (see FIG. 8) of the busbar electrode portions 40, 50.
It is preferable to apply the flux 70 from the side surface of the bus bar electrode portion 40, 50 onto the electrode layer 20, 22 to an area that is at least 1 time the width W1, W3 of the bus bar electrode portion 40, 50, and it is more preferable to apply the flux 70 to an area that is at least 1.5 times the width W1, W3 of the bus bar electrode portion 40, 50.

The connector portions 60, 61 of the wiring member 11, which have solder 71 formed on their surfaces, are placed on the busbar electrode portions 40, 50 covered with flux 70, and heated to melt the solder 71, thereby bonding the connector portions 60, 61 of the wiring member 11 to the busbar electrode portions 40, 50 with the solder 71 (bonding process).
At this time, the components of the flux 70 are vaporized, and the interfacial peeling layers 26, 36, which are resin layers, are formed.

Then, the base materials 2, 3 having sealing materials 6a, 6b formed on their surfaces are adhered and sealed so that the sealing materials 6a, 6b face each other and sandwich the solar cell 10, and a terminal box or the like is provided as necessary to complete the solar cell module 1.

According to the solar cell module 1 of this embodiment, the adhesive strength of the interface between the first busbar electrode portion 40 and the first interface peeling layer 26 is greater than the adhesive strength of the interface between the sealing material 6a and the first interface peeling layer 26, and the adhesive strength of the interface between the sealing material 6a and the first interface peeling layer 26 is greater than the adhesive strength of the interface between the front electrode layer 20 and the first interface peeling layer 26. Therefore, when the first base material 2 is pulled to peel off the sealing material 6a from the solar cell string 5, as shown in FIG. 10(a), the first interface peeling layer 26 has a portion in contact with the first busbar electrode portion 40 remaining in a cross section that does not pass through the first finger electrode portion 41, and a portion in contact with the front electrode layer 20 peels off preferentially. Also, as shown in FIG. 10(b), the first interface peeling layer 26 has a portion in contact with a part of the first finger electrode portion 41 and the first busbar electrode portion 40 remaining in a cross section that passes through the first finger electrode portion 41. As a result, the first bus bar electrode portion 40 is not substantially peeled off from the front electrode layer 20 .
According to the solar cell module 1 of the present embodiment, the adhesive strength of the interface between the second busbar electrode portion 50 and the second interface peeling layer 36 is greater than the adhesive strength of the interface between the sealing material 6b and the second interface peeling layer 36, and the adhesive strength of the interface between the sealing material 6b and the second interface peeling layer 36 is greater than the adhesive strength of the interface between the back electrode layer 22 and the second interface peeling layer 36. Therefore, when the second base material 3 is pulled to peel off the sealing material 6b from the solar cell string 5, as shown in FIG. 11(a), the second interface peeling layer 36 has a portion in contact with the second busbar electrode portion 50 remaining in a cross section that does not pass through the second finger electrode portion 51, and a portion in contact with the back electrode layer 22 is preferentially peeled off. Also, as shown in FIG. 11(b), the second interface peeling layer 36 has a portion in contact with a part of the second finger electrode portion 51 and the second busbar electrode portion 50 remaining in a cross section that passes through the second finger electrode portion 51. As a result, the second bus bar electrode portion 50 covered with the second interface release layer 36 is not substantially peeled off from the back electrode layer 22 .
In this way, according to the solar cell module 1 of this embodiment, even if the base materials 2, 3 and the sealing materials 6a, 6b are peeled off from the solar cell string 5, the parts that mainly contribute to electrical conduction do not peel off along with the base materials 2, 3 and the sealing materials 6a, 6b, so that initial defects, etc. can be accurately evaluated.

According to the solar cell module 1 of the first embodiment, the interfacial peeling layers 26, 36 are provided across the busbar electrode portions 40, 50 and onto the electrode layers 20, 22, and extend from the side surfaces of the busbar electrode portions 40, 50 to an area that is 0.5 times or more the widths W1, W3 of the busbar electrode portions 40, 50. Therefore, the busbar electrode portions 40, 50 are not easily peeled off from the electrode layers 20, 22.

According to the solar cell module 1 of this embodiment, the first interface peeling layer 26, which is preferentially subjected to cohesive failure, is interposed between the sheet-like sealing material 6a and the thin-film first collector 25. That is, a portion that is easily subjected to cohesive failure is intentionally created on the first collector 25 to suppress cohesive failure of the first collector 25, so that the first bus bar electrode portion 40 of the first collector 25 is unlikely to peel off from the front electrode layer 20 in the portion of the first collector 25 covered with the first interface peeling layer 26 even if the sealing material 6a floats. Therefore, the long-term reliability is high.
Similarly, according to the solar cell module 1 of this embodiment, the second interface peeling layer 36, which is preferentially subjected to cohesive failure, is interposed between the sheet-like sealing material 6b and the thin-film second collector 35. That is, a portion that is easily subjected to cohesive failure is intentionally created on the second collector 35 to suppress cohesive failure of the second collector 35, so that in the portion of the second collector 35 covered with the second interface peeling layer 36, the second bus bar electrode portion 50 of the second collector 35 is unlikely to peel off from the back electrode layer 22 even if the sealing material 6b floats. Therefore, the long-term reliability is high.

A solar cell module according to a second embodiment of the present invention will be described below. Note that the same components as those in the solar cell module 1 according to the first embodiment will be denoted by the same reference numerals and the description thereof will be omitted.

The solar cell module of the second embodiment of the present invention is a so-called PERC type solar cell module, and the solar cell is different from that of the first embodiment.

12 , a solar cell 110 of the second embodiment includes an opposite conductivity type semiconductor layer 112, an antireflection layer 113, and a first collector 25 on one main surface of a one conductivity type semiconductor substrate 111 (hereinafter also simply referred to as semiconductor substrate 111). The solar cell 110 includes a back surface field layer 116, a protective layer 117, a back electrode layer 118, and a second collector 35 on the other main surface of the semiconductor substrate 111.
In the solar cell 110 , the antireflection layer 113 , the reverse conductivity type semiconductor layer 112 , the semiconductor substrate 111 , the back surface field layer 116 , and the protective layer 117 constitute a photoelectric conversion section 120 .
That is, in the solar cell 110 , a first collector 25 is formed on the front side of the photoelectric conversion section 120 , and a rear electrode layer 118 and a second collector 35 are formed on the rear side of the photoelectric conversion section 120 .

The semiconductor substrate 111 is an n-type or p-type semiconductor substrate, and for example, a p-type or n-type silicon substrate can be used.
The opposite conductivity type semiconductor layer 112 is a semiconductor substrate having a conductivity type opposite to that of the semiconductor substrate 111, and for example, an n-type or p-type silicon thin film layer can be used.
In the solar cell 110 of this embodiment, the semiconductor substrate 111 is composed of a p-type silicon substrate, and the reverse conductivity type semiconductor layer 112 is composed of an n-type silicon thin film layer, and a PN junction is formed between the semiconductor substrate 111 and the reverse conductivity type semiconductor layer 112.

The anti-reflection layer 113 is a layer that reduces the reflectance on the light receiving surface of the solar cell 110 , and is a layer that confines light that has entered the photoelectric conversion section 120 within the photoelectric conversion section 120 .
The anti-reflection layer 113 is an insulating layer having insulating properties, and for example, a silicon oxide layer, a silicon nitride layer, an aluminum oxide layer, or the like can be used.

The back surface field layer 116 is a so-called BSF (Back Surface Field) layer, and is a semiconductor layer having the same conductivity type as the semiconductor substrate 111 .
The back surface field layer 116 has a dopant concentration higher than that of the semiconductor substrate 111 and is a layer that forms an internal electric field.
The back surface field layer 116 can be formed, for example, by diffusing a dopant element such as boron or aluminum into the other main surface of the semiconductor substrate 111 .
The back surface field layer 116 of this embodiment uses aluminum as a dopant element.

The protective layer 117 is a passivation layer that reduces defect levels that cause minority carrier recombination at the interface with the semiconductor substrate 111 .
The protective layer 117 is an insulating layer having insulating properties, and for example, a silicon oxide layer, a silicon nitride layer, an aluminum oxide layer, or the like can be used.
When the semiconductor substrate 111 is of p-type, the protective layer 117 is preferably made of a material having a negative fixed charge, such as aluminum oxide, whereas when the semiconductor substrate 111 is of n-type, the protective layer 117 is preferably made of a material having a positive fixed charge, such as silicon nitride.

The back electrode layer 118 is an electrode that collects electricity from the photoelectric conversion section 120 and also serves as an extraction electrode that extracts electricity to the wiring member 11 .
The back electrode layer 118 is a conductive layer having electrical conductivity, and may be made of, for example, a metal such as aluminum, silver, gold, platinum, or palladium, or an alloy of these metals.

Next, a description will be given of the positional relationship of each member of the solar cell module of the second embodiment. The description will be centered mainly on the solar cell 110, and a description of the same parts as in the first embodiment will be omitted.

12 to 14, the solar cell 110 has a reverse conductivity type semiconductor layer 112, an anti-reflection layer 113, and a first collector electrode 25 laminated on one main surface of a semiconductor substrate 111. The solar cell module has a front-side bottomed hole 121 that penetrates the anti-reflection layer 113 and has the reverse conductivity type semiconductor layer 112 as a bottom, as shown in FIG.
The first collector 25 is filled in the front-side bottomed hole 121, and is in contact with the reverse conductivity type semiconductor layer 112 inside the front-side bottomed hole 121. That is, the first collector 25 is electrically connected to the reverse conductivity type semiconductor layer 112 through the front-side bottomed hole 121.
Specifically, the front-side bottomed hole 121 is a bottomed groove that extends continuously or intermittently in the extension direction of the first bus bar electrode portion 40 .
In the portion other than the front-side bottomed hole 121 , the opposite conductivity type semiconductor layer 112 is covered with an antireflection layer 113 .

When viewed in cross section perpendicular to the extension direction of the first busbar electrode portion 40, the first interface peeling layer 26 spreads from both sides of the first solder layer 12 in the width direction (lateral direction X), passes through the end face of the first busbar electrode portion 40, and extends onto the anti-reflection layer 113.

As shown in FIGS. 12 to 14, the solar cell 110 has a back surface field layer 116, a protective layer 117, and a back electrode layer 118 laminated on the other main surface of a semiconductor substrate 111.
The solar cell 110 has a bottomed back hole 122 that penetrates the protective layer 117 and has the back surface field layer 116 as a bottom. The back surface hole 122 is filled with a back surface electrode layer 118, and the back surface electrode layer 118 and the back surface field layer 116 are in contact with each other inside the back surface hole 122. That is, the back surface electrode layer 118 is electrically connected to the back surface field layer 116.
Specifically, the rear side blind hole 122 is a blind groove that extends continuously or intermittently in the extension direction of the second bus bar electrode portion 50 .
In the portion other than the bottomed back hole 122 , the protective layer 117 is interposed between the back electrode layer 118 and the semiconductor substrate 111 , and the back electrode layer 118 and the semiconductor substrate 111 are not directly connected to each other.

12 and 14 , when viewed in a cross section perpendicular to the extension direction of the second busbar electrode portion 50, the second interface peeling layer 36 comes into contact with both end faces of the second solder layer 13 in the width direction (lateral direction X) and spreads from both sides of the second solder layer 13. In addition, the second interface peeling layer 36 passes over the protruding portions 52 and 53 of the second busbar electrode portion 50, covers the end faces of the second busbar electrode portion 50, and further extends onto the back electrode layer 118.

12 is greater than the adhesive strength at the interface between the anti-reflection layer 113 and the first interface peeling layer 26. That is, the interface between the sealant 6a and the first interface peeling layer 26 is more difficult to peel off than the interface between the anti-reflection layer 113 and the first interface peeling layer 26.
The adhesive strength at the interface between the sealing material 6b and the second interface peeling layer 36 is greater than the adhesive strength at the interface between the back electrode layer 118 and the second interface peeling layer 36. In other words, the interface between the sealing material 6b and the second interface peeling layer 36 is more difficult to peel off than the interface between the back electrode layer 118 and the second interface peeling layer 36.

Next, a method for manufacturing the solar cell module of the second embodiment will be described.

First, similarly to conventional PERC type solar cells, a photoelectric conversion unit 120 is formed, a back electrode layer 118 is formed on the back side of the photoelectric conversion unit 120, and a first collector electrode 25 is formed on the reverse conductivity type semiconductor layer 112 and a second collector electrode 35 is formed on the back electrode layer 118 to form the solar cell 110 (collector electrode formation process).

Next, as shown in FIG. 15, flux 70 having fluidity is applied to the bus bar electrode portions 40, 50 of the solar cell 110 (application step).
Specifically, on the front side of the solar cell 110, the coating is applied intentionally overflowing from above the first busbar electrode portion 40 so as to straddle from above the busbar electrode portion 40 onto the anti-reflection layer 113. Similarly, on the back side of the solar cell 10, the coating is applied intentionally overflowing from above the busbar electrode portion 50 so as to straddle from above the second busbar electrode portion 50 onto the back-side electrode layer 118.
At this time, similarly to the first embodiment, on the front side, the flux 70 is applied from the side surface of the first bus bar electrode portion 40 onto the anti-reflection layer 113 to an area that is 0.5 times or more the width W1 of the bus bar electrode portion 40, and on the back side, the flux 70 is applied from the side surface of the second bus bar electrode portion 50 onto the back electrode layer 118 to an area that is 0.5 times or more the width W3 of the second bus bar electrode portion 50.

The connector portions 60, 61 of the wiring member 11, which have solder 71 formed on their surfaces, are placed on the busbar electrode portions 40, 50 covered with flux 70, and heated to melt the solder 71, thereby bonding the connector portions 60, 61 of the wiring member 11 to the busbar electrode portions 40, 50 with the solder 71 (bonding process).

Then, the substrates 2 and 3 having sealing materials 6a and 6b formed on their surfaces are bonded together so that the sealing materials 6a and 6b face each other and sandwich the solar cell 110 to seal it, and a terminal box or the like is provided as necessary to complete the solar cell module.

According to the solar cell module of the second embodiment, the adhesive strength at the interface between the first bus bar electrode portion 40 and the first interface peeling layer 26 is greater than the adhesive strength at the interface between the sealing material 6a and the first interface peeling layer 26, and the adhesive strength at the interface between the sealing material 6a and the first interface peeling layer 26 is greater than the adhesive strength at the interface between the anti-reflection layer 113 and the first interface peeling layer 26. Therefore, when the first base material 2 is pulled and peeled off from the solar cell string 5, the portion of the first interface peeling layer 26 that is in contact with the first bus bar electrode portion 40 remains, and the portion that is in contact with the anti-reflection layer 113 peels off preferentially. As a result, the first bus bar electrode portion 40 is not substantially peeled off from the anti-reflection layer 113.
Furthermore, according to the solar cell module of the second embodiment, the adhesive strength at the interface between the second busbar electrode portion 50 and the second interface peeling layer 36 is greater than the adhesive strength at the interface between the sealing material 6b and the second interface peeling layer 36, and the adhesive strength at the interface between the sealing material 6b and the second interface peeling layer 36 is greater than the adhesive strength at the interface between the back electrode layer 118 and the second interface peeling layer 36. Therefore, when the second base material 3 is pulled and peeled off from the solar cell string 5, the portion of the second interface peeling layer 36 that is in contact with the second busbar electrode portion 50 remains, and the portion that is in contact with the back electrode layer 118 is preferentially peeled off. As a result, the second busbar electrode portion 50 is not substantially peeled off from the back electrode layer 118.
In this way, according to the solar cell module of the second embodiment, even if the base materials 2, 3 and the sealing materials 6a, 6b are peeled off from the solar cell string 5, the parts that contribute to electrical conduction do not peel off along with the base materials 2, 3 and the sealing materials 6a, 6b, so that initial defects, etc. can be accurately evaluated.

According to the solar cell module of the second embodiment, the first interface peeling layer 26 is provided across the first busbar electrode portion 40 and across the photoelectric conversion portion 120, and extends from the side of the first busbar electrode portion 40 to a range that is 0.5 times or more the width W1 of the first busbar electrode portion 40, so that the first busbar electrode portion 40 is not easily peeled off from the photoelectric conversion portion 120.

According to the solar cell module of the second embodiment, the second interface peeling layer 36 is provided across from the second busbar electrode portion 50 to the back-side electrode layer 118 and extends from the side surface of the second busbar electrode portion 50 to a range that is 0.5 times or more the width W3 of the second busbar electrode portion 50, so that the second busbar electrode portion 50 is not easily peeled off from the back-side electrode layer 118.

A solar cell module according to a third embodiment of the present invention will be described.

As shown in FIG. 16 , the solar cell module of the third embodiment further includes interface peeling layers 246 , 256 that cover the outside of the wiring member 11 with respect to the photoelectric conversion section 21 in the solar cell module of the first embodiment.
The interfacial peeling layers 246 and 256, like the first interfacial peeling layer 26, are light-transmitting organic compound layers containing a rosin compound as a main component, and are flux layers formed by hardening the flux 70.

Next, the positional relationship between the components of the solar cell module of the third embodiment will be described.

16 , the interfacial peeling layers 246, 256 are located outside the wiring members 11, 11 with respect to the photoelectric conversion unit 21 when viewed in cross section perpendicular to the extension direction of the first bus bar electrode portion 40. The interfacial peeling layers 246, 256 are also interposed between the wiring members 11, 11 and the sealing materials 6a, 6b, and cover the side and outer side surfaces of the wiring members 11, 11. In other words, the interfacial peeling layers 246, 256 cover the exposed parts of the wiring members 11, 11 from the interfacial peeling layers 26, 36, and also cover part of the interfacial peeling layers 26, 36.

Here, the relationship of adhesive strength between the bus bar electrode portions 40, 50, the interfacial peeling layers 26, 36, 246, 256, and the sealing materials 6a, 6b will be described.

The adhesive strength at the interface between the wiring members 11, 11 and the interfacial peeling layers 246, 256 is greater than the adhesive strength at the interface between the interfacial peeling layers 246, 256 and the sealing materials 6a, 6b.
The adhesive strength between the wiring members 11 , 11 and the bus bar electrode portions 40 , 50 via the solder layers 12 , 13 is greater than the adhesive strength at the interface between the wiring members 11 , 11 and the interface peeling layers 246 , 256 .
That is, the interfaces between the wiring members 11, 11 and the bus bar electrode portions 40, 50 are less likely to peel off than the interfaces between the wiring members 11, 11 and the interfacial peeling layers 246, 256, and are less likely to peel off than the adhesive strength of the interfaces between the interfacial peeling layers 246, 256 and the sealing materials 6a, 6b.

The manufacturing method of the solar cell module of the third embodiment is almost the same as the manufacturing method of the solar cell module of the first embodiment, and after the bonding process, flux 70 is applied again to the wiring member 11, and then the wiring member 11 is sandwiched and sealed between base materials 2 and 3 on which sealing materials 6a and 6b are formed.

According to the solar cell module of the third embodiment, the interface between the wiring members 11, 11 and the busbar electrode portion 40, 50 is more difficult to peel off than the interface between the wiring members 11, 11 and the interfacial peeling layers 246, 256, and is more difficult to peel off than the adhesive strength of the interface between the interfacial peeling layers 246, 256 and the sealing materials 6a, 6b. Therefore, when the first base material 2 is pulled to peel off the sealing material 6a from the solar cell string 5, the interfacial peeling layer 246 undergoes cohesive failure as shown in FIG. 17(a) or is preferentially peeled off at the interface with the sealing materials 6a, 6b. As a result, in a cross section perpendicular to the extension direction of the first busbar electrode portion 40, the portion in contact with the wiring member 11 remains, and the portion in contact with the sealing material 6a is preferentially peeled off. Therefore, the wiring member 11 is not substantially peeled off from the first busbar electrode portion 40. Similarly, when the second base material 3 is pulled to peel off the sealing material 6b from the solar cell string 5, the interface peeling layer 256 undergoes cohesive failure or is preferentially peeled off at the interface with the sealing materials 6a, 6b as shown in Fig. 17(b) . As a result, in a cross section perpendicular to the extension direction of the second bus bar electrode portion 50, the portion in contact with the wiring member 11 remains, and the portion in contact with the sealing material 6b is preferentially peeled off. Therefore, the wiring member 11 is not substantially peeled off from the second bus bar electrode portion 50.

According to the solar cell module of the third embodiment, the interface peeling layers 246, 256, which are preferentially subjected to cohesive failure, are interposed between the sealing materials 6a, 6b and the wiring members 11, 11. That is, because a portion which is easily subjected to cohesive failure is intentionally created on the wiring members 11, 11, the wiring members 11, 11 covered with the first interface peeling layer 26 are unlikely to peel off from the bus bar electrode portions 40, 50 even if the sealing materials 6a, 6b float. Therefore, the long-term reliability is high.

A solar cell module according to a fourth embodiment of the present invention will be described.

The solar cell module of the fourth embodiment differs from that of the second embodiment in the structure of the solar cell string. That is, the solar cell string of the fourth embodiment includes a solar cell 110, a wiring member 11, and solder layers 12 and 13, as shown in Fig. 18, and includes interface peeling layers 246 and 256 on the outer side of the wiring member 11, similar to the third embodiment.

In the first embodiment described above, the front electrode layer 20 and the rear electrode layer 22 are formed on the photoelectric conversion unit 21, and the collector electrodes 25, 35 are electrically connected to the photoelectric conversion unit 21 via the front electrode layer 20 and the rear electrode layer 22, but the present invention is not limited to this. The collector electrodes 25, 35 may be formed directly on the photoelectric conversion unit 21.

In the above-described embodiment, the collecting electrodes 25, 35 include the finger electrode portions 41, 51, but the present invention is not limited to this. The collecting electrodes 25, 35 do not necessarily have to include the finger electrode portions 41, 51.

In the above embodiment, each solar cell is connected by two wiring members 11, but the present invention is not limited to this. Each solar cell may be connected by one wiring member 11, or may be connected by three or more wiring members 11.

In the above embodiment, the solder layers 12, 13 are formed by the solder 71 coated on the surface of the wiring member 11, but the present invention is not limited to this. The solder layers 12, 13 may be formed by solder prepared separately from the wiring member 11.

In the above embodiment, the first busbar electrode portion 40 and the second busbar electrode portion 50 have different widths, but the present invention is not limited to this. The first busbar electrode portion 40 and the second busbar electrode portion 50 may have the same width.

In the above embodiment, the first bus bar electrode portion 40 has the same width as the wiring member 11, but the present invention is not limited to this. The first bus bar electrode portion 40 may have a width wider than the wiring member 11.
In the above embodiment, the width of the second bus bar electrode portion 50 is wider than the width of the wiring member 11, but the present invention is not limited to this. The second bus bar electrode portion 50 may have the same width as the width of the wiring member 11.

In the above embodiment, a single-sided light receiving solar cell module in which the main surface of the first substrate 2 is the light receiving surface has been described, but the present invention is not limited to this. The present invention may be a double-sided light receiving solar cell module in which both the main surface of the first substrate 2 and the main surface of the second substrate 3 are light receiving surfaces.

In the above embodiment, the interface peeling layer is formed of flux, but the present invention is not limited to this, and the interface peeling layer may be formed of other materials.

In the above-described embodiments, each component may be freely substituted or added between the respective embodiments as long as it falls within the technical scope of the present invention.

REFERENCE SIGNS LIST 1 Solar cell module 2 First substrate 3 Second substrate 5 Solar cell string 6a, 6b Sealing material 10, 10a, 10b, 110 Solar cell 11 Wiring member 12, 13 Solder layer 20 Front electrode layer 21 Photoelectric conversion section 22 Rear electrode layer 25 First collector electrode 26 First interface peeling layer 35 Second collector electrode 36 Second interface peeling layer 40 First bus bar electrode section 41 First finger electrode section 50 Second bus bar electrode section 51 Second finger electrode section 52, 53 Extension section 111 One conductivity type semiconductor substrate 112 Reverse conductivity type semiconductor layer 113 Anti-reflection layer 116 Back surface field layer 117 Protective layer 118 Back surface electrode layer 120 Photoelectric conversion section 246, 256 Interface peeling layer

Claims (11)

A solar cell module in which a solar cell and a wiring member are disposed between two base materials, and a sealant is filled between the two base materials,
the solar cell has a front electrode layer, a back electrode layer, and a photoelectric conversion unit sandwiched between the front electrode layer and the back electrode layer, and a bus bar electrode unit is provided on at least one of the front electrode layer and the back electrode layer;
the wiring member is bonded to the bus bar electrode portion via a solder layer,
The solar cell has an interface peeling layer,
the interfacial peeling layer covers at least a part of a side surface of the bus bar electrode portion and extends across the one electrode layer when the solar cell is viewed in cross section,
an adhesive strength at an interface between the bus bar electrode portion and the interfacial peeling layer is greater than an adhesive strength at an interface between the sealing material and the interfacial peeling layer,
a bonding strength at the interface between the sealing material and the interfacial release layer is greater than a bonding strength at the interface between the one electrode layer and the interfacial release layer. The solar cell module according to claim 1 , wherein the interfacial peeling layer extends on the one electrode layer from a side surface of the bus bar electrode portion to an area that is 0.5 times or more the width of the bus bar electrode portion. The solar cell module according to claim 2 , wherein the interfacial peeling layer extends on the one electrode layer from a side surface of the bus bar electrode portion to an area 1.5 times or more the width of the bus bar electrode portion. The solar cell module according to claim 1 , wherein the one electrode layer is formed of a transparent conductive oxide. 5. The solar cell module according to claim 1, wherein the interface release layer is a flux layer containing a rosin compound, and the halide content of the flux component is 0.5 wt% or less. The bus bar electrode portion is wider than the solder layer,
The solar cell module according to claim 1 , wherein the interfacial peeling layer covers a portion of the bus bar electrode portion exposed from the solder layer when the solar cell is viewed in cross section. A battery module that receives light from the front electrode layer side and generates electricity based on the photoelectric conversion unit,
the front electrode layer and the rear electrode layer are provided with busbar electrode portions,
The solar cell module according to claim 1 , wherein the busbar electrode portion of the back electrode layer is wider than the busbar electrode portion of the front electrode layer. The encapsulant includes an encapsulating sheet,
The solar cell module according to claim 1 , wherein the bus bar electrode portion is formed of a thin film. The solar cell module according to claim 1 , wherein the bus bar electrode portion remains on the one electrode layer when the sealing material is peeled off. a second interface peel layer is interposed between the wiring member and the sealing material,
The solar cell module according to claim 1 , wherein an adhesive strength between the wiring member and the bus bar electrode portion is greater than an adhesive strength between the second interface release layer and the sealing material. A solar cell module in which a solar cell and a wiring member are disposed between two base materials, and a sealant is filled between the two base materials,
The solar cell has a photoelectric conversion unit, and a bus bar electrode unit is provided on the photoelectric conversion unit,
the wiring member is bonded to the bus bar electrode portion via a solder layer,
The solar cell has an interface peeling layer,
the interfacial peeling layer covers at least a portion of a side surface of the bus bar electrode portion and extends across the photoelectric conversion portion when the solar cell is viewed in cross section,
an adhesive strength at an interface between the bus bar electrode portion and the interfacial peeling layer is greater than an adhesive strength at an interface between the sealing material and the interfacial peeling layer,
a solar cell module, wherein an adhesive strength at the interface between the sealing material and the interfacial peeling layer is greater than an adhesive strength at the interface between the photoelectric conversion section and the interfacial peeling layer.

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