JPH0638433Y2 - Solar cell module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to an improvement of a solar cell module configured by electrically connecting a large number of solar cells.

(B) Conventional technology Generally, when a solar cell is used as a power source, a high output is required. Therefore, it is necessary to electrically connect a large number of solar cells in series or in parallel to form a solar cell module. There is.

As shown in FIG. 3 and FIG. 4, a conventional solar cell module is provided with a large number of solar cells (1) and a large number of two interconnectors (2) in a set of two solar cells. The rule (1) is composed of a rectangular silicon cell, and the front electrode (N electrode) (3) is formed along the long side of the light-receiving surface side, and the back surface is formed on almost the entire surface opposite to the light-receiving surface. An electrode (P electrode) (4) is formed. Each interconnector (2)
Is made of a metal plate, is linearly spot-welded to the N electrode (3) and the P electrode (4), and electrically connects each solar battery cell (1). Further, each solar cell (1) is formed such that the orientation of the cleavage plane (5) is parallel to the N electrode (3) forming side of each solar cell (1) as shown in FIG. .

Next, a method for manufacturing this solar cell module will be described. FIG. 3 shows an outline of a method for welding the N electrode (3) of the solar battery cell (1), and FIG. 4 shows a method of welding the P electrode (4) of the solar battery cell (1). This is an overview. The same technique is basically applied to both welding of the N electrode (3) and the P electrode (4).

First, the solar cell (1) is attached to the plate-shaped welding jig (6a) (6
b) Set on top. Then, the N electrode (3) or P
The interconnector (2) is aligned and fixed on the surface of the electrode (4). The welding points (8) are sequentially shifted by the welding machine (7) only in the X direction, and the welding points for which the welding conditions determined in advance so as to obtain the desired welding strength are determined.
Welding is performed so that the welding points are on a straight line. A schematic diagram of the welding state at this time is shown in FIG. In addition, (9) is a welding electrode. Here, multi-point welding, that is, the reason why the welding point is divided into several points, is to (a) increase the area of the welding point, and (b) to prevent the welding power from increasing and the welding equipment becoming large. , (C) In some cases, the solar cell itself is not flat but warped, so to prevent cracking of the solar cell due to welding, (d)
This is to prevent the residual welding strain from increasing during welding. Further, by arranging the plurality of welding points on a straight line, movement of the welding points can be performed very easily only in the X direction, for example.

(C) Problems to be solved by the invention Today, GaAs, which has a high electric output conversion efficiency, is being used as a new solar cell along with the increase in power and weight of solar cell arrays.
Solar cell arrays using cells, lightweight thin Si cells, thin GaAs cells, etc. are considered as main candidates. Therefore, if the same welding technique as the conventional technique is applied to such a solar battery cell, the following problems arise. The main point is that the GaAs cell or the like has a strong cleavage property in the crystal itself, and when the orientation is as in the conventional example described above, for example, during the welding, welding strains are accumulated and the solar battery cell is Very easy to crack. In the case of thin Si cells, thin cells have a smaller heat capacity than solar cells of conventional thickness, so the heating during welding becomes steeper and cracks occur in the solar cells compared to conventional thick cells. Easier to do. In particular, if the welding power is increased in order to obtain a strong connection strength, the crack generation rate increases, and the work yield cannot be ignored.

This invention has been made in view of the above circumstances, and when a GaAs cell, a lightweight thin cell, a thin GaAs cell, etc. is used as a solar cell, each solar cell is welded with an interconnector to connect each solar cell. It is an object of the present invention to provide a solar cell module capable of preventing cracks and cracks in solar cells due to welding distortion during welding and heating during welding during electrical connection.

(D) Means for Solving the Problems The present invention comprises a large number of rectangular plate-shaped solar cells, all of which are formed along one side of a light-receiving side surface thereof. It has an electrode and a back electrode formed on substantially the entire surface opposite to the light receiving surface thereof, and further, in the state where these solar cells are arranged in a plane with a space therebetween, each front electrode and each back electrode. Each electrode is provided with an interconnector for electrically connecting each solar cell by a plurality of spot weldings or a plurality of spot solders located on a straight line along one side of the light-receiving surface, and one side of the light-receiving surface is formed by each of the above-mentioned ones. The solar cell module is formed so as to intersect with the orientation of the cleavage plane of the solar cell.

(E) Action The present invention is intended to prevent cracks or cracks in the solar cells when the interconnector is spot-welded or spot-soldered to the front and back electrodes of each solar cell.

(F) Embodiment This invention will be described in detail based on the embodiment shown in the drawings.

Since the basic configuration of the present invention is the same as that of the conventional example, the same parts are designated by the same reference numerals and the description thereof will be omitted. The difference from the conventional example is that each solar cell (1) is formed so that the cleavage plane (10) of the solar cell (1) is oriented in a direction intersecting the N electrode formation side of each solar cell (1) as shown in FIG. In point. A silicon cell is preferable as the solar cell (1), but a GaAs cell may be used instead.

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

First, in the case of N electrode (3) welding as shown in FIG.
The solar battery cell (1) is set on the electrode welding jig (6a, see FIG. 3). Then, the interconnector (2) is aligned and fixed on the surface of the N electrode (3). Here first
As shown in the figure, the welding electrode (9, see FIG. 3) is pressed onto the interconnector (2) set on the N electrode (3) of the solar battery cell (1) to perform the first welding. . At the second welding point, welding is performed by shifting the position of the welding machine (7) in the X direction in FIG. Hereinafter, the welding work after the third point is repeated. FIG. 1 shows a schematic view of a state where the interconnector (2) is welded to the solar cell (1) when the number of welding points (8) is five. Although an example of the P electrode (4) is not shown in the figure, it is the same as that of the N electrode. The interconnector (2) may be connected to the N electrode (3) and the P electrode (4) by soldering instead of the above welding.

As described above, by making the azimuth of the cleavage plane of the solar battery cell not coincident with the N electrode formation side of the solar battery cell,
The rate of cracks and cracks in the solar cells during welding can be made extremely small. Further, in the completed module, when the cell is broken due to the crack of one cell, in the conventional case, for example, in FIG. However, due to the influence of the horizontal series shown in FIG. 4, non-uniformity of the generated voltage and current in the module occurred, which caused the failure of the module. However, according to the present invention, even if there is a crack, it is in the diagonal direction of the cell, and it is possible to maintain a part of the electrical connection in the column, so that there is little possibility of causing the above-mentioned malfunction, and the entire module is The reliability of can be improved.

Note that these rectangular solar cells are generally obtained by dicing a wafer into a plurality of cells. An orientation flat is provided on the wafer, and dicing is performed in parallel or perpendicularly to this orientation flat.
It is usually divided into multiple cells.

It has been empirically known that the number of scratches on the edge of the wafer, which is the main cause when the wafer breaks in the manufacturing process of the solar cell, is relatively large around the orientation flat.
In this case, in the conventional case, since the orientation of the cleavage plane is perpendicular to the orientation flat, the cracks generated from the scratched spots proceed along a plurality of rectangular cells in all the corresponding columns in the wafer, Damage a lot. However, according to the present invention, since the orientation of the cleavage plane intersects the orientation flat at a constant angle, the crack generated from the scratched portion intersects the sides of the plurality of rectangular divided portions in the wafer. Proceed and reduce cell damage. Therefore, the number of cells taken from the wafer is larger than in the conventional case, and there is an advantage that the production yield is improved.

(G) Effect of the Invention According to the present invention, in a case where the interconnector is electrically connected by a plurality of spot weldings or a plurality of spots solders which are located on a straight line along one side of the light receiving surface, the interconnector is limited to a limited area. The welding area is expanded, the welding equipment is downsized, cracks due to cell warpage are prevented, residual welding strain is reduced to obtain the desired connection strength, and the movement of the welding point is straight and very easy. Since one side of the light receiving surface is formed so as to intersect with the azimuth of the cleavage plane of each of the solar cells,
When an interconnector is welded to each solar battery cell, cracks or cracks in the solar battery cell can be reduced as compared with the conventional case due to distortion caused by the welding and heat generated during welding. Further, in the solar cell module, even if the cell is broken due to cracks or the like, it is possible to partially maintain the electrical connection, and the reliability of the entire module can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view of an N electrode welding state showing an embodiment of the present invention, FIG. 2 is a view corresponding to FIG. 1 of a conventional example, and FIG. 3 is a schematic perspective view showing a conventional N electrode welding, FIG. 4 is a schematic perspective view showing conventional P electrode welding. (1) …… Solar cell, (2) …… Interconnector, (3) …… N electrode (front electrode), (4) …… P electrode (back electrode), (10) …… Cleaved surface.

Claims (1)

[Scope of utility model registration request] 1. A large number of rectangular plate-shaped solar cells, each of which has a front electrode formed along one side of its light-receiving surface and a surface opposite to the light-receiving surface. A back electrode formed on substantially the entire surface, and further, in the state where these solar cells are arranged in a plane with a space therebetween, for each front electrode and each back electrode, on one side of the light receiving surface. Provide an interconnector that electrically connects each solar cell by a plurality of point welding or a plurality of point solders located along a straight line, and one side of the light receiving surface intersects with the azimuth of the cleavage plane of each solar cell. A solar cell module, which is characterized by being formed.