JPH04330785A - Integrated solar cell module - Google Patents

Abstract

PURPOSE:To effectively use a substrate by extending an output terminal along edges of a plurality of generating elements in parallel aligning direction of the elements in a solar cell module in which the plurality of generating elements are aligned in parallel, and further connected in series. CONSTITUTION:Transparent electrode layers 2 for constituting generating elements and parts 8 becoming output terminals are formed by a mask patterning on a glass board 1. The electrodes 2 are aligned laterally in such a manner that each set has two, and the parts 8 becoming the terminals are extended at upper and lower edges of the board 1. The layers 2 and the terminals 8 are screen printed with conductive paste 3. The paste is formed of silver paste, printed at a right side edge on the layers 2 and at a center on the terminals 8. With this structure, even if the elements are formed in a slender shape, since the terminals are formed along a lateral direction of the board, the parts which do not contribute to generation can be reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated solar cell module, and particularly to a power solar cell module suitable for extracting a large current.

0002

2. Description of the Related Art In power solar cells that require a large current to be extracted, the side edges of adjacent solar cell elements are connected in series to reduce internal resistance. As one method for mass-producing it, a method as shown in FIGS. 15 and 16 has been implemented. This method is
After patterning a plurality of transparent electrode layers 2 on a glass substrate 1, a conductive paste 3 and an insulating paste 4 are patterned into strips on the side edges of the transparent electrode layer, and then a photoactive layer 5 and a metal electrode layer 6 are formed. After sequentially forming the entire surface, the conductive paste 3 portion is welded (LW) between this paste and the metal electrode layer 6 by irradiation with a laser beam,
4 portions of the insulating paste are fused (LS). By doing this, in the case shown in FIG. 15, an integrated solar cell module is formed in which two power generating elements 7, 7 are connected in series and have extraction terminals 8, 8 on both sides. This method is disclosed in detail in Japanese Unexamined Patent Publication No. 102274/1983.

In order to further reduce the internal resistance of an integrated solar cell module having such a configuration, a structure shown in FIG. 17 has been considered. That is, the conductive paste 3 is extended 3' onto the transparent electrode layer 2 in a comb-like shape to facilitate current collection from the transparent electrode layer and to lower the internal resistance. Note that the extended portion 3' of the conductive paste is covered with an insulating paste 4' in order to prevent short circuit with the metal electrode layer 6.
covered with. Such an integrated solar cell module is disclosed in Japanese Patent Application Laid-Open No. 63-119586, but because of the comb-shaped extension, the power generation area is reduced and the expected power increase is not achieved. In addition, the comb-like extensions 3' of the conductive paste tend to short-circuit with the metal electrode layer 6, resulting in a high failure rate.

[0004] Therefore, the structure of FIG. 15 described first is preferable. In this structure, in order to increase the amount of power that can be taken out, each power generating element may be made elongated by decreasing its horizontal width and increasing its vertical width, as shown in FIG. However, if the power generation element is elongated, the lead terminals 8,8 formed on both sides of the battery module will also become elongated, increasing the amount of wasted parts, and if the lead terminals are made too thin, it will be difficult to solder the lead wires. be. In order to facilitate soldering, it has been considered to widen one end 8' of the lead-out terminal 8 as shown in FIG. Since the laser beam needs to be bent, precision is required, and since the laser beam temporarily stops at the point where the direction changes, the power generating element may be locally abnormally heated and damaged while the laser beam stops. In order to avoid such drawbacks, Japanese Unexamined Patent Publication No. 1-209769 describes providing an insulating region below the direction change point, but this method has the drawback of becoming complicated.

[0005]

[Problems to be Solved by the Invention] According to the present invention, even when the shape of each power generating element is elongated, the extraction electrode does not occupy a large part of the part, and the scanning of the laser beam can also be done in a straight line. This is designed to improve mass productivity and prevent damage from laser beams.

[0006]

[Means for Solving the Problems] In order to solve the above problems, the present invention extends the extraction terminal in the direction in which a plurality of power generating elements are arranged side by side.

[0007]

[Function] With this structure, even if each power generation element is made into an elongated shape, the extraction terminals are formed along the lateral direction of the substrate, so that the portion that does not contribute to power generation becomes small.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a state in which a transparent electrode layer 2 for constructing a power generation element and a portion 8 to be an extraction terminal are formed on a glass substrate 1 by mask patterning. The transparent electrode layers 2 are arranged in pairs in the horizontal direction,
The portion 8 serving as the extraction terminal extends in the direction in which the portions serving as the power generation elements are arranged side by side, that is, along the upper and lower edges of the glass substrate 1.

FIG. 2 shows a state in which a conductive paste 3 is screen printed on the transparent electrode layer 2 and the lead-out terminal 8. This conductive paste is made of, for example, silver paste, and is printed on the transparent electrode layer 2 along its right edge and on the lead-out terminal 8 at its center.

FIGS. 3 and 4 show a state in which an insulating paste 4, for example a silicon dioxide paste, is screen printed. This insulating paste extends linearly in the vertical direction from the upper edge to the lower edge of the glass substrate 1 along the conductive paste 3, and the portion that crosses the extraction terminal 8 is exposed to the conductive paste 3 from a laser beam, which will be described later. It is wide for protection. The insulating paste 4 also extends in the left-right direction between the transparent electrode groups 2 and the lead-out terminals 8.

After printing the conductive paste 3 and the insulating paste 4 in this manner, these pastes are cured by baking, and then a photoactive layer 5 and a metal electrode layer 6 are formed on the entire surface, respectively. The photoactive layer 5 is formed by dividing amorphous silicon into three layers of P, I, and N by a PCVD method or the like.
The metal electrode layer 6 is formed of Al, Ti, Cr, Ag, etc. by vapor deposition or sputtering.

Next, a laser beam is irradiated from the side of the metal electrode layer 6 to perform welding (LW) and fusing (LS). That is, by scanning a laser beam along the insulating paste 4, fusing is performed to divide it into power generation elements 7, and
Takeout terminals 8 and 8 along the upper and lower edges of the glass substrate 1
form. Furthermore, by scanning the laser beam along the conductive paste 3, the metal electrode layer 6 and the conductive paste 3 are welded and connected, and the two power generating elements are connected in series. A battery module is connected in parallel to the extraction terminal 8. Here, since the insulating paste 4 is printed on parts that do not require welding, even if the laser beam for welding is scanned linearly, it will not have an adverse effect on the conductive paste at the extraction terminal 8 part.

With this configuration, two sets of modules each having two power generation elements connected in series are connected in parallel, and electric power can be extracted from the extraction terminal 8.

[0014] Also, if necessary, two sets of modules can be separated by dividing the insulating substrate 1 into two left and right from the center.
Two solar cells can be formed by connecting two power generation elements in series.

In the above embodiments, the transparent electrode 2 is formed by mask patterning. That is, the glass substrate 1
After forming a transparent conductive film on the entire surface, etching is performed using a mask to form a transparent electrode 2 in a desired pattern. However, as the size of the glass substrate 1 increases, patterning accuracy decreases, contributing to poor quality, and the effective power generation area relatively decreases due to the increase in the etched portion, which tends to deteriorate the characteristics. Furthermore, it takes time to attach the mask and perform etching, which causes high costs.

In view of these points, in other embodiments shown in FIGS. 8 to 14, a transparent electrode layer having a desired shape is obtained by laser beam irradiation and conductive paste.

Another embodiment will be explained below, as shown in FIG.
1 shows a state in which a laser beam is scanned after forming a transparent electrode layer 2 on the entire surface of a glass substrate 1. The laser beam is scanned linearly from one end of the glass substrate 1 to the other. The electrode layer 2 is divided into a portion 2a corresponding to the power generation element 2 and a portion 8a corresponding to the extraction terminal 8.
...separated into... 9... indicates lines separated by the laser beam.

FIG. 9 shows a state in which a conductive paste 3 is screen printed on the transparent electrode layer 2. This conductive paste 3 is printed along the side edge of the portion corresponding to the power generation element 2a, and the portion 8 corresponding to the extraction terminal is printed.
In a, it is printed in the center. Further, a predetermined portion of the portion 2a corresponding to the plurality of power generation elements and a portion 8a corresponding to the extraction terminal are connected by the conductive paste 3. A cross section of this connection portion is shown in FIG.

FIG. 10 shows a state in which an insulating paste 4 is further screen printed after printing a conductive paste, and then a photoactive layer 5 and a metal electrode layer 6 are formed on the entire surface, and then a laser beam is applied from the side of the metal electrode layer 6. Weld by irradiating the beam (L
W) and fusing (LS), a plurality of power generation elements are connected in series. The letters LW and LS shown in FIG. 10 indicate that the laser beam is scanned linearly from this position.

FIGS. 12 to 14 show cross sections of the respective parts in FIG. 10 after the photoactive layer 5 and the metal electrode layer 6 have been formed and then welded and cut by a laser beam.

[0021]

Effects of the Invention As described above, the present invention provides an arrangement in which a plurality of power generation elements are arranged in parallel and connected in series, and the extraction terminal is connected to the edge of each power generation element in the direction in which the power generation elements are arranged in parallel. , even if each power generation element is made elongated to extract a large amount of power, the extraction terminal will not be so large, making it possible to use the board effectively. Since the beam can be scanned linearly from one end of the substrate to the other, it is excellent in mass production and does not damage the photoactive layer.

[0022] Also, when patterning the transparent electrode with a laser beam, the laser beam can be scanned linearly from one end of the substrate to the other, making it suitable for mass production.

Furthermore, by patterning as in the example, a plurality of solar cell modules can be formed in parallel on one substrate, so it is possible to use them in a parallel connection state as is, or to form a plurality of solar cell modules in parallel. It can also be divided and used, widening the scope of application.

[Brief explanation of drawings]

FIG. 1 shows a pattern of a transparent electrode layer formed on a glass substrate.

FIG. 2: Pattern of conductive paste.

FIG. 3: Pattern of insulation paste.

FIG. 4 is an enlarged view of the main part of FIG. 3.

FIG. 5 is a sectional view taken along line V-V in FIG. 4;

FIG. 6 is a sectional view taken along VI-VI in FIG. 4;

FIG. 7 is a sectional view taken along VII-VII in FIG. 4;

FIG. 8 shows a pattern after a transparent electrode layer is irradiated with a laser beam in another example.

FIG. 9: Pattern of conductive paste.

FIG. 10: Pattern of insulation paste.

FIG. 11 is a sectional view taken along line XI-XI in FIG. 9;

FIG. 12 is a sectional view taken along line XII-XII in FIG. 10;

FIG. 13 is a sectional view taken along line XIII-XIII in FIG. 10;

FIG. 14 is a sectional view taken along line XIV-XIV in FIG. 10;

FIG. 15 shows a pattern according to a conventional example.

FIG. 16 is a sectional view taken along line XVI-XVI in FIG. 15;

FIG. 17 shows a pattern according to another conventional example.

FIG. 18 is a sectional view taken along line XVIII-XVIII in FIG. 17;

FIG. 19 shows another conventional example.

FIG. 20 shows another conventional example.

[Explanation of symbols]

1 Glass substrate (insulating substrate) 2 Transparent electrode layer 3 Conductive paste 4 Insulating paste 5 Photoactive layer 6 Metal electrode layer 7 Power generation element 8 Output terminal

Claims (5)

[Claims] Claim 1: A plurality of power generation elements formed by sequentially stacking a transparent electrode layer, a photoactive layer, and a metal electrode layer are arranged in parallel on an insulating substrate, and the side edges of each power generation element are connected in series, The power generating element at both ends is provided with extraction terminals,
An integrated solar cell module characterized in that the extraction terminal extends along the edge of each power generation element in the direction in which the plurality of power generation elements are arranged side by side. 2. The integrated solar cell module according to claim 1, wherein a plurality of sets of modules are formed on a single insulating substrate, and each module has a common extraction terminal. 3. A method in which a conductive paste and an insulating paste are provided on the side edges of a transparent electrode layer, and by linearly scanning an energy beam such as a laser beam, a plurality of power generation elements are melted and connected in series. 3. The integrated solar cell module according to claim 1, wherein the conductive paste is extended to the extraction terminal portion, and a portion where the energy beam crosses the extraction terminal is covered with an insulating paste. 4. The integrated solar cell module according to claim 2, wherein a plurality of solar cells are formed by dividing a plurality of sets of modules. 5. A transparent electrode layer is formed on substantially the entire surface of the insulating substrate, and an energy beam is linearly scanned from one end of the insulating substrate to the other, so that the transparent electrode layer is connected to each power generation element and the extraction layer. 4. The integrated solar cell module according to claim 3, wherein the integrated solar cell module is separated into parts corresponding to the terminals, and at least the transparent electrode layer corresponding to the outermost power generating element and the transparent electrode layer corresponding to the extraction terminal are connected by conductive paste. .