JP2001156312A - Method of manufacturing thin-film solar cell and method of processing through-hole in thin-film substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a thin-film solar cell which has good solar cell characteristics without generating cracks in a first electrode layer, is simple and excellent in mass productivity. SOLUTION: A connection hole and a current collection hole of a thin-film solar cell are formed by electrically connecting adjacent unit photoelectric conversion parts separated from each other in series via a connection hole and a current collection hole for electrical series connection. In the manufacturing method of processing using a mold comprising a punch and a die, a punch P1 and a spare die D1 having an opening having an inner diameter smaller than the outer diameter of the punch.
The opening of the spare die D1 is previously processed by the punch P1 so that the outer diameter of the punch and the inner diameter of the opening of the die are substantially the same. The connection hole and the current collecting hole are processed by using a mold comprising:

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a thin-film solar cell, and a thin-film function formed by laminating functional thin films such as thin-film solar cells, semiconductors and photoconductors, and thin films such as electrode layers and protective layers. The present invention relates to a thin film substrate through hole processing method for forming a plurality of predetermined through holes in an element substrate or a substrate on which at least a part of a thin film is formed.

[0002]

2. Description of the Related Art At present, research and development of clean energy are being promoted from the standpoint of environmental protection. Above all, solar cells are attracting attention because of their infinite resources (solar rays) and no pollution. A typical example of a solar cell (photoelectric conversion device) in which a plurality of solar cell elements formed on the same substrate are connected in series is a thin-film solar cell.

Thin-film solar cells are considered to be the mainstream of solar cells in the future because of their thinness, light weight, low production cost, and easy area enlargement. Demand is expanding for business use and general residential use, which are used for such purposes.

Conventional thin-film solar cells use a glass substrate, but research and development of a flexible solar cell using a plastic film has been advanced in terms of weight reduction, workability, and mass productivity. Further, a device using a film substrate insulated from a flexible metal material has been developed. Taking advantage of this flexibility, mass production has become possible by roll-to-roll or stepping roll manufacturing methods.

In the above-mentioned thin film solar cell, a first electrode (hereinafter, also referred to as a lower electrode), a photoelectric conversion layer comprising a thin film semiconductor layer, and a second electrode (hereinafter, also referred to as a transparent electrode) are formed on a flexible electrically insulating film substrate. ) Are formed in a plurality of photoelectric conversion elements (or cells). By repeatedly electrically connecting the first electrode of a certain photoelectric conversion element and the second electrode of the adjacent photoelectric conversion element, the first electrode of the first photoelectric conversion element and the second electrode of the last photoelectric conversion element Required voltage can be output. For example,
Alternating with an inverter, AC 100 as commercial power source
In order to obtain V, the output voltage of the thin-film solar cell must be 100 V
The above is desirable, and actually several tens or more elements are connected in series.

[0006] Such a photoelectric conversion element and its serial connection are formed by forming an electrode layer and a photoelectric conversion layer, patterning each layer, and combining them. An example of the configuration and the manufacturing method of the solar cell is disclosed in, for example,
No. 0-233517 and Japanese Patent Application No. 11-19306.

FIGS. 7A and 7B show an example of a thin-film solar cell described in the above-mentioned Japanese Patent Application Laid-Open No. Hei 10-233517. FIG. 7A is a plan view, and FIG.
It is sectional drawing along C, (c) is E in (a).
E shows a sectional view.

A first electrode layer, a photoelectric conversion layer, and a second electrode layer are sequentially laminated on a long film substrate made of an electrically insulating and flexible resin. The three electrode layer and the fourth electrode layer are stacked to form a back electrode. The photoelectric conversion layer is, for example, a pin junction of amorphous silicon. As the material for the film substrate, a polyimide film, for example, a film having a thickness of 50 μm is used.

Other materials for the film include polyethylene naphthalate (PEN) and polyether sulfone (P
ES), polyethylene terephthalate (PET), or aramid-based films can be used.

Next, an outline of the manufacturing process will be described below.

First, a connection hole h1 is formed in a film substrate by using a punch, and silver is formed as a first electrode layer on one side (front side) of the substrate by sputtering, for example, to a thickness of 100 nm. On the opposite side (the back side)
Similarly, a silver electrode is formed as an electrode layer. The first electrode layer and the third electrode layer overlap with each other on the inner wall of the connection hole h1 and conduct.

The electrode layer is made of not only silver (Ag) but also Al, C
A metal such as u or Ti may be formed by sputtering or electron beam evaporation, or a multilayer film of a metal oxide film and a metal may be used as the electrode layer. After the film formation, on the front side, the first electrode layer is laser-processed into a predetermined shape, and the lower electrodes 11 to 16 are patterned. A portion adjacent to the lower electrodes 11 to 16 is a single separation line g2.
For separation between two rows of photoelectric conversion elements connected in series and the periphery conductive portion f, two separation lines g2 are formed, and the lower electrodes 11 to 16 are surrounded by the separation lines. After the current collecting hole h2 is opened again by using a punch, an a-Si layer is formed as a photoelectric conversion layer p on the front side by plasma CVD. A film having a width W2 is formed using a mask, and the same separation line as that of the first electrode layer is formed only between the two-row elements by laser processing. The width W2 may extend over the connection hole h1.

Further, a transparent electrode layer (ITO layer) is formed on the front side as a second electrode layer. However, a mask is applied between the two element rows and on both side edges of the substrate parallel to the two element rows to form connection holes h1.
Is formed on the element portion only. As the transparent electrode layer, in addition to ITO (Indium Sulfate), SnO
2. An oxide conductive layer such as ZnO can be used.

Next, a layer made of a low-resistance conductive film such as a metal film is formed as a fourth electrode layer on the entire back surface. Due to the formation of the fourth electrode, the second electrode and the fourth electrode are overlapped on the inner wall of the current collecting hole h2, and conduction is achieved. On the front side, a separation line having the same pattern as that of the lower electrode is formed by laser processing, and individual second electrodes u1
To u6, the third electrode and the fourth electrode are simultaneously laser-processed on the back side, the connection electrodes e12 to e56, and the power extraction electrodes o1 and o2 are individualized, and the separation line g3 on the front side is formed at the periphery of the substrate. A separation line g2 is formed so as to overlap,
One separation line is formed between adjacent electrodes.

A separation line g3 (inside the peripheral conductive portion f) is provided on the periphery surrounding all the thin-film solar cell elements at once and on the adjacent boundary between the two rows of series-connected solar cell elements. There are no layers in the separation line g3. On the rear side, there is a separation line g2 (inside the peripheral conductive portion f) at the periphery surrounding all the electrodes collectively and at the adjacent boundary between the two rows of serially connected electrodes. There are no layers in the separation line g2.

In this manner, the power extraction electrode o1-current collection hole h2-upper electrode u1, photoelectric conversion layer, lower electrode l1-connection hole h
1—connection electrode e12—upper electrode u2, photoelectric conversion layer, lower electrode 12—connection electrode e23—.. .—Upper electrode u6, photoelectric conversion layer, lower electrode 16—connection hole h1—electricity in the order of power extraction electrode o2. The serial connection of the conversion elements is completed.

Since the third electrode layer and the fourth electrode layer have the same electric potential, they may be treated as a single connection electrode layer in the following description for convenience of explanation.

FIG. 8 is a simplified perspective view showing the structure of a thin-film solar cell for easy understanding of the structure. In FIG. 8, the unit photoelectric conversion element 62 formed on the front surface of the substrate 61 and the connection electrode layer 63 formed on the back surface of the substrate 61 are completely separated into a plurality of unit units, respectively, and are formed with their separation positions shifted. ing. Therefore, the current generated in the photoelectric conversion layer 65, which is the amorphous semiconductor portion of the element 62, is first collected in the transparent electrode layer 66, and then the current collecting holes 67 formed in the transparent electrode layer region.
(H2) through the connection electrode layer 63 on the back surface, and further through the connection electrode 68 (h1) for series connection formed outside the transparent electrode layer region of the device in the connection electrode layer region, and connected to the device. Reaching the lower electrode layer 64 extending outside the transparent electrode layer region of the adjacent element, the two elements are connected in series.

FIGS. 9 (a) to 9 (g) show simplified manufacturing steps of the above-mentioned thin film solar cell. Plastic film 71
Is used as a substrate (step (a)), connection holes 78 are formed in the substrate (step (b)), and a first electrode layer (lower electrode) is formed on both surfaces of the substrate.
After forming the first electrode layer 74 and the third electrode layer (part of the connection electrode) 73 (step (c)), a current collecting hole 77 is formed at a position separated from the connection hole 78 by a predetermined distance (step (d)). Step (c)
Between the step (d) and the step (d), there is a step of patterning the lower electrode by laser processing the first electrode layer (lower electrode) 74 into a predetermined shape, but the figure of this step is omitted here. .

Next, a semiconductor layer 75 serving as a photoelectric conversion layer and a transparent electrode layer 76 serving as a second electrode layer are sequentially formed on the first electrode layer 74 (step (e) and step (f)). Then, a fourth electrode layer (connection electrode layer) 79 is formed on the third electrode layer 73 (step (g)). Thereafter, the thin films on both sides of the substrate 71 are separated and processed using a laser beam to form a series connection structure as shown in FIG.

In FIG. 9, the connection between the transparent electrode layer 76 and the fourth electrode layer 79 in the current collecting hole h2 is shown by two layers with each layer being superposed. Are electrically treated as one layer, and are shown in one layer.

In the manufacturing process of the thin film solar cell, the step (b) of forming the connection hole 78 and the step (d) of forming the current collecting hole 77 are conventionally performed by punching using a punch or energy beam such as laser beam. By laser processing. However, in laser processing
In the case of an infrared laser such as a YAG laser, since thermal processing is performed, unevenness is formed on the inner surface and the periphery of the hole due to heat, and the electrode layer may be separated. On the other hand, in the case of a short-wavelength laser such as an excimer laser, it is possible to perform processing without forming irregularities, but it is difficult to apply because of poor mass productivity and high operating cost.

Regarding the punching process using a so-called punch, which is performed by using a die composed of a punch and a die, the applicant of the present application has proposed a continuous hole forming apparatus with high mass productivity (Japanese Patent Laid-Open No. 8-139352). Gazette). FIG. 10 is a schematic cross-sectional view of a hole opening device in the apparatus for manufacturing a thin film solar cell described in the above publication, and includes a substrate transporting unit, a through hole processing unit, and a processing position detection hole processing unit. The substrate 1a sent out from the unwinding roll R1 sequentially includes a hole P3 for processing position detection, a hole P2 for a current collecting hole, and a hole P1 for a connection hole.
Thus, a predetermined number of processing position detection holes, current collection holes, and connection holes are opened at predetermined positions, and after being cleaned by the cleaning device, the processing roll is taken up by the take-up roll R2. For various hole positions,
The transport direction and transport distance of the substrate 1a are controlled with reference to the processing position detection hole.

FIG. 11 is an enlarged schematic view of an opening portion of a conventional opening device. The opening includes a punch P having a hole shape in the substrate, a stripper plate Ps having an opening having the same cross-sectional shape as the punch P, and a die D having the same opening. The die D and the punch P are configured to have a predetermined clearance C. The substrate 1a transported and stopped between the die D and the stripper plate Ps is pressed by the stripper plate Ps. In this state, the punch P punches (penetrates) the substrate 1a, and a hole is formed in the substrate 1a.

[0025]

However, the above-described conventional method of punching various through-holes of a thin-film solar cell using a punch as described above has the following problems.

In the case of the opening by the punch, there is a problem that the film substrate surface on the processing surface side sags and large burrs are generated on the back surface side. As a result, a circumferential crack is generated in the first electrode layer 74 formed on the substrate 71 in FIG. 9 (see FIG. 4A described later). Therefore, the photoelectric conversion layer 75 cannot cover the cracks generated in the first electrode layer 74, and the first electrode layer 74 and the third electrode layer 76 come into contact with each other, thereby decreasing the fill factor of the solar cell. As a result, There is a problem that conversion efficiency is reduced.

In general, in punching, in order to reduce sag on the front side and burrs on the back side as described above,
It is said that machining should be performed with the clearance C between the punch P and the die D as small as possible. However, if the clearance C between the punch P and the die D is reduced, not only does the manufacturing cost of the mold rise, but also the clearance The production of punches and dies with small size was technically difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to improve a method of processing a connection hole or a current collection hole to form a crack in a first electrode layer. A method for manufacturing a thin-film solar cell that has good solar cell characteristics without any generation, is simple and has excellent mass productivity, and forms a plurality of predetermined through holes in a substrate such as the solar cell, semiconductor, and photoconductor. It is an object of the present invention to provide a thin-film substrate through-hole processing method which is suitable for the above.

[0029]

Means for Solving the Problems To solve the above-mentioned problems, the invention of claim 1 is to provide a first electrode layer as a lower electrode layer, a photoelectric conversion layer,
A photoelectric conversion unit in which transparent electrode layers (second electrode layers) are sequentially laminated; and a third electrode layer and a fourth electrode layer serving as connection electrode layers formed on the back surface of the substrate. The connection electrode layers are separated into unit portions by displacing the positions, and a connection hole for electrical series connection formed outside the transparent electrode layer formation region and a current collection hole formed in the transparent electrode layer formation region are formed. A method for manufacturing a thin-film solar cell, wherein adjacent unit photoelectric conversion portions separated from each other on the surface are electrically connected in series, wherein the connection hole and the current collection hole are formed by a punch and a die. In a manufacturing method of processing using a mold comprising: preparing a punch and an auxiliary die having an opening having an inner diameter smaller than the outer diameter of the punch, and pre-processing the opening of the auxiliary die by the punch. do it, The outer diameter of the punch and the inner diameter of the opening of the die are set to be substantially the same, and the connection hole and the current collecting hole are processed using a die formed of the processed die and the punch. .

The present invention is based on the finding of the following experimental facts. In the opening portion (FIG. 11) of the conventional opening device, the clearance between the die and the punch is optimally about 3 to 5% of the thickness of the workpiece. That is, if the thickness of the substrate as the workpiece is 0.05 mm, the clearance is about 0.0015 mm to 0.0025 mm on one side. However, when actually processing and assembling the die, it is necessary to process a large area, so that the die is also large in size. Therefore, a very difficult situation arises in terms of manufacturing technology.

For example, a number of situations have been observed where the clearance is caused by one side. As a result, the workpiece is pulled toward the die by the clearance or the deviation due to the assembling condition at the time of cutting, and when the workpiece is drawn into a soft material such as a film substrate, the substrate elongates. Become. At that time, it was found that the electrode layer formed on the surface side was cracked. Due to this effect,
The photoelectric conversion layer cannot completely cover the cracks generated in the first electrode layer, the first electrode layer and the second electrode layer come into contact, the fill factor is reduced, and the output characteristics of the solar cell are reduced. There was a thing.

According to the present invention, the clearance can be minimized by processing the die with the punch. Further, it is possible to suppress a phenomenon that the punch is caused by one side of the die at the time of assembling the mold. Therefore, it is possible to minimize the elongation of the substrate at the time of forming the holes, and to suppress the occurrence of cracks in the electrode layer.

The present invention can be applied not only to solar cells but also to thin film functional elements such as semiconductors and photoreceptors. A semiconductor substrate, a solar cell,
A plurality of predetermined through holes are punched on a substrate of a thin film functional element or a substrate on which at least a part of the thin film is formed by laminating a functional thin film such as a photoconductor and a thin film such as an electrode layer and a protective layer. In a method of processing a through-hole of a thin film substrate using a die comprising a die, a preliminary die having the punch and an opening having an inner diameter smaller than the outer diameter of the punch is prepared, and the opening of the preliminary die is prepared. Is processed in advance with the punch so that the outer diameter of the punch and the inner diameter of the opening of the die are substantially the same, and the through-hole is formed by using a die including the processed die and the punch. It is formed (claim 2).

In the method according to claim 1 or 2, the inner diameter of the opening of the spare die is smaller by 0.01 mm to 0.06 mm than the outer diameter of the punch (claim 3). This is preferable for the reasons described below.

Further, in the method according to claim 1 or 2, the hardness of the material used for the preliminary die is smaller than the hardness of the material used for the punch.
Is preferred in terms of processing.

[0036]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an enlarged schematic view of a mold having a spare die according to the present invention. Only the differences from the conventional mold will be described. The opening of the preliminary die D1 is made smaller in advance by the clearance C than the outer shape of the punch P1. In this state, the work is carried out in an empty state (a state where there is no workpiece) by assembling into a manufacturing apparatus for actually forming a hole, and the clearance C of the preliminary die D1 is removed by the punch P1.
And remove the part. FIG. 2 is an enlarged schematic diagram of a mold showing a state after processing of a spare die. As described above, the clearance between the punch P1 and the die D2 can be minimized.

In this embodiment, carbide is used for the punch P1, high-speed steel is used for the preliminary die D1, and the quenching condition is HRC5.
5, but is not limited to this. For example, the condition for quenching the punch P1 with high-speed steel is H
The quenching condition on the die D1 side was set to punch P1.
The hardness of the punch P1 by making it weaker than the conditions on the side
The hardness may be higher than 1, and the material is not limited. The clearance C is 0.05mm on one side
It is as follows. If it is larger than this, the tip of the punch may be hung when processing the die with the punch, or the die side may not be processed well.

When the clearance is reduced, a situation such as a one-side contact occurs due to the assembling accuracy when assembling the mold.
There are places on the circumference of the die that are processed by the punch and places that are not, so 0.005-0.03 mm on one side
In other words, when converted to a diameter difference, 0.01 to
A range of 0.06 mm is preferred. In this example, the one having 0.01 mm on each side was used. When the die D1 is processed by the punch P1, when the die D1 is incorporated into an actual manufacturing apparatus, the processing state such as the processing pressure, the bending of the mold, and the vibration is slightly different depending on the apparatus. It is desirable to perform trial processing in advance by incorporating it into a manufacturing apparatus.

Using the mold prepared as described above,
A method for manufacturing a solar cell is described below. In the present embodiment, a polyimide film having a thickness of 0.05 mm is used as the substrate 1a, but an insulating plastic film such as PEN, PES, PET, or aramid may be used. Further, the film thickness used in the embodiment is 0.05 mm, but is not limited to this thickness.

FIG. 5 is a plan view showing the arrangement of the position detecting holes and the connection holes of the substrate in the embodiment of the present invention. Substrate 1a
Are opened in the order of the position detection hole h3 and the connection hole h1. The position detection holes h3 are formed at predetermined length intervals of the unit pattern of the solar cell, and are used for positioning of subsequent conveyance.

First, the position detecting hole h3 is opened, and thereafter, the substrate 1
a was conveyed by a predetermined distance and stopped, and a row of a plurality of connection holes h1 was formed by one punching operation in the width direction of the film. After repeating this a predetermined number of times, the position detection hole h3 is opened. The distance between the position detection holes h3 is set to the length of one basic pattern, and by repeating this, a large number of basic patterns can be formed on the long substrate 1a. After the opening, the surface of the substrate 1a was cleaned by blowing with an adhesive roll or non-contact ultrasonic waves in the same apparatus.

The first electrode layer 74 was formed on this surface, and the third electrode layer 73 was formed on the surface opposite to the first electrode layer 74 with a thickness of several hundred nm by sputtering (see FIG. 9C). As a material,
In addition, a multilayer structure film such as Al or Ag / transparent conductive layer can be used. Either of the first electrode layer 74 and the third electrode layer 73 may be first, but the first electrode layer 74 is preferably first. After that, it is attached to the same opening device and the position detecting hole h
3 is detected by the position detection sensor and stopped.
A predetermined number of rows of 2 were opened. Also in this case, the connection hole h1 is formed by the same method.

FIG. 6 is a plan view of the substrate of this embodiment in which a current collecting hole is further provided. In the embodiment, the interval between the current collecting hole arrays is set to 5 mm, but the interval can be set to an arbitrary value depending on the solar cell pattern. In this case, the shape of the hole does not necessarily have to be a circle. For example, in order to improve solar cell characteristics, it is preferable that the area of the current collecting hole h2 is as small as possible and the peripheral length is as long as possible. Further, in this embodiment, one line of holes is formed in the substrate transfer direction in one operation. However, a plurality of lines can be simultaneously formed to improve mass productivity.

After the above steps, a thin film semiconductor layer was formed as the photoelectric conversion layer 75. In this embodiment, a nip junction was formed using hydrogenated amorphous silicon (a-Si: H) -based material deposited by a normal glow discharge decomposition method (FIG. 9).
(E)). A transparent electrode layer was formed thereon as a second electrode layer. Although an oxide conductive film such as ITO or ZnO can be used for this layer, in this embodiment, ITO by sputtering is used.
A film was formed (see FIG. 9 (f)). At this time, a film is not formed in the connection hole h1 by, for example, covering with a mask when forming the film. Next, a fourth electrode layer 79 made of a metal film or the like was finally formed on the substrate surface opposite to the surface on which the solar cells were formed. In this embodiment, Ni is used as a material, but the material is not limited to Ni. The film formation method is sputtering (see FIG. 9 (g)).

Finally, in order to form a series structure, three layers from the second electrode layer to the first electrode layer on the front surface and two third and fourth electrode layers on the back surface are cut by a YAG laser, Pattern.

FIG. 3 shows the results of comparing the characteristics (power generation efficiency) of the solar cell manufactured as described above and a plurality of solar cells manufactured by the conventional method. FIG. 3 shows that the characteristics of the solar cell manufactured in this example have little variation and are very stable. FIG. 4 shows a diagram (micrograph) of the state of the hole processed according to the present invention and the state of the electrode surface in the vicinity thereof, in comparison with the conventional method.

FIG. 4A shows a photomicrograph of the current collecting hole 77 in FIG. 9D processed by the conventional method and the substrate surface near this hole. FIG. 4 (b) shows a micrograph when processed according to the present invention. 4 (a) and 4 (b), the left side shows the surface of the second electrode layer and the right side shows a part of the hole, and shows a photograph of the substrate surface observed from the light receiving surface side of the solar cell.

In the case of FIG. 4A, there are many linear grooves on the surface of the electrode layer as seen on the surface of the bark. This is a crack formed on the surface of the electrode layer caused by the drilling. 4 (a) and 4 (b), it can be seen that the cracks on the surface of the electrode layer are less around the holes produced in this example. In addition, in the case of FIG. 4A, it can be seen that sagging occurs in the inner peripheral portion of the hole. This is considered to be due to the fact that the above-mentioned clearance is minimized, so that the substrate is drawn into the die side during processing, and the extension of the substrate is reduced.

In the case of FIG. 4B, cracks on the electrode surface are reduced due to the reduced elongation of the substrate. Therefore, it is considered that the coverage of the first electrode layer in the photoelectric conversion layer is sufficient, and no deterioration in characteristics occurs. Further, according to the present invention, it is possible to manufacture the mold without worrying about the clearance, so that the manufacturing cost of the mold can be reduced. As a result, the cost of the solar cell can be reduced, and a low-cost solar cell can be easily and stably manufactured with good mass productivity.

[0051]

According to the present invention, as described above, a first electrode layer, a photoelectric conversion layer, and a transparent electrode layer (second electrode layer) as a lower electrode layer are sequentially formed on the surface of a film substrate having electrical insulation. A photoelectric conversion unit formed by stacking, and a third electrode layer and a fourth electrode layer serving as connection electrode layers formed on the back surface of the substrate, wherein the photoelectric conversion unit and the connection electrode layer are displaced from each other in a unit part; And separated from each other on the surface through a connection hole for electrical series connection formed outside the transparent electrode layer formation region and a current collection hole formed in the transparent electrode layer formation region. A method of manufacturing a thin-film solar cell in which adjacent unit photoelectric conversion portions are electrically connected in series, wherein the connection hole and the current collection hole are processed using a mold including a punch and a die. In the above, the punch and the punch A spare die having an opening having an inner diameter smaller than the diameter is prepared, and the opening of the spare die is pre-processed by the punch so that the outer diameter of the punch and the inner diameter of the opening of the die are substantially the same. Like nothing
Since the connection hole and the current collection hole were processed using a die including the processed die and the punch,
The processing state of the connection hole and the current collection hole is improved, and the first electrode layer is not cracked. Therefore, the thin film solar cell having good solar cell characteristics without a decrease in the fill factor can be stably mass-produced. Can be manufactured.

Further, the above-mentioned claims 2 to 4 of the present invention
The thin film substrate through hole processing method according to the invention can be suitably used for processing a substrate through hole of a thin film functional element such as a semiconductor or a photoreceptor other than a solar cell, and can contribute to improvement in quality and mass productivity.

[Brief description of the drawings]

FIG. 1 is an enlarged schematic view of a mold having a spare die according to an embodiment of the present invention.

FIG. 2 is an enlarged schematic view of a mold showing a state after processing a spare die of FIG. 1;

FIG. 3 is a diagram showing a comparison between the present invention and a conventional method with respect to a measurement result of power generation efficiency of a solar cell.

FIG. 4 is a photomicrograph showing a comparison between the present invention and a conventional method for a current collecting hole and a substrate surface near the hole.

FIG. 5 is a plan view showing an arrangement of a position detection hole and a connection hole of the substrate.

FIG. 6 is a plan view of the substrate in which a current collecting hole is further opened in FIG. 5;

FIG. 7 illustrates an example of a configuration of a thin-film solar cell.

FIG. 8 is a perspective view showing a schematic configuration of a thin-film solar cell.

FIG. 9 is a view schematically showing a manufacturing process of a conventional thin-film solar cell.

FIG. 10 is a schematic cross-sectional view of a conventional opening device for a thin-film solar cell.

FIG. 11 is an enlarged schematic view of an opening portion of a conventional opening device.

[Explanation of symbols]

1a: substrate, C: clearance, D1: spare die, D2:
Die, P1: punch, Ps: stripper plate.

Claims (4)

[Claims] A photoelectric conversion unit comprising: a first electrode layer as a lower electrode layer, a photoelectric conversion layer, and a transparent electrode layer (second electrode layer) sequentially laminated on a surface of a film substrate having electrical insulation; A third electrode layer and a fourth electrode layer as connection electrode layers formed on the back surface of the substrate, wherein the photoelectric conversion unit and the connection electrode layer are separated from each other by being displaced from each other into unit portions; The adjacent unit photoelectric conversion portions separated from each other on the surface are electrically connected via a connection hole for electrical series connection formed outside the formation region and a current collection hole formed in the transparent electrode layer formation region. A method of manufacturing a thin-film solar cell connected in series, wherein the connection hole and the current collecting hole are processed using a mold comprising a punch and a die, wherein the punch and an outer diameter of the punch are provided. Has a smaller inner diameter A spare die having an opening was prepared, and the opening of the spare die was previously processed by the punch so that the outer diameter of the punch and the inner diameter of the opening of the die were substantially the same, and this processing was performed. A method for manufacturing a thin-film solar cell, wherein the connection hole and the current collection hole are processed using a mold including a die and the punch. 2. A substrate for a thin film functional element comprising a laminate of a functional thin film such as a semiconductor, a solar cell and a photoconductor and a thin film such as an electrode layer and a protective layer on a surface of a film substrate having electrical insulation. In a thin-film substrate through-hole processing method in which a plurality of predetermined through-holes are formed on a substrate on which at least a part of a thin film is formed using a mold including a punch and a die, the punch and the outer diameter of the punch are smaller than the outer diameter of the punch. Prepare a spare die having an opening having an inner diameter of the dimensions, pre-processing the opening of this spare die by the punch,
A thin film substrate, wherein the outer diameter of the punch and the inner diameter of the opening of the die are substantially the same, and the through-hole is formed using a die comprising the processed die and the punch. Through hole processing method. 3. The thin-film solar cell according to claim 1, wherein the inner diameter of the opening of the spare die is smaller than the outer diameter of the punch by 0.01 mm to 0.06 mm. A method for manufacturing a battery or a method for processing a through hole in a thin film substrate. 4. The method according to claim 1, wherein the hardness of the material used for the spare die is smaller than the hardness of the material used for the punch. Or a method of processing a through hole in a thin film substrate.