JP2020107795A - Groove processing tool, and grooving method and grooving apparatus for thin film solar cell using the same - Google Patents

Abstract

To provide a groove processing tool for a solar cell capable of manufacturing an integrated thin-film solar cell with high yield.SOLUTION: A groove processing tool includes a rod-shaped body 81, and a truncated cone-shaped cutting edge region 82 formed at the tip of the body 81. The cutting edge region 82 includes a bottom surface 83 and a side surface 84 extending from the bottom surface 83 toward the body 81, a corner formed by the bottom surface 83 and the side surface 84 forms a cutting edge 85, and the groove processing tool in which a groove portion 86 is formed from the bottom surface 83 toward the body 81 is used to perform groove processing on a thin film of a thin film solar cell.SELECTED DRAWING: Figure 2

Description

The present invention relates to a groove processing tool used when manufacturing a thin film solar cell, a groove processing method using the groove processing tool, and a groove processing apparatus.

In a thin film solar cell, an integrated structure in which a plurality of unit cells are connected in series on a substrate is common. As an example of the thin-film solar cell, a method of manufacturing a chalcopyrite compound-based thin-film solar cell using a chalcopyrite compound semiconductor as a light absorption layer will be described. The chalcopyrite compound includes, in addition to CIGS (Cu(In, Ga)Se2), CIGSS (Cu(In, Ga)(Se, S)2), CIS(CuInS2), and the like.

FIG. 5: is a schematic diagram which shows the manufacturing process of a CIGS thin film solar cell. First, as shown in FIG. 7A, a Mo electrode layer 2 to be a lower electrode on the plus side is formed on an insulating substrate 1 made of soda lime glass (SLG) or the like by a sputtering method, and then a light absorption layer is formed. The groove S for separating the lower electrode is formed by scribing on the previous thin film solar cell substrate.

Then, as shown in FIG. 5B, a light absorption layer 3 made of a compound semiconductor (CIGS) thin film is formed on the Mo electrode layer 2 by a vapor deposition method, a sputtering method or the like, and a heterojunction is formed thereon. The buffer layer 4 made of the ZnS thin film or the like is formed by the CBD method (chemical bath deposition method), and the insulating layer 5 made of the ZnO thin film is formed thereon. Then, for the inter-electrode contact reaching the Mo electrode layer 2 by scribing at a position laterally separated from the lower electrode separating groove S by a predetermined distance with respect to the thin film solar cell substrate before forming the transparent electrode layer. The groove M1 is formed.

Subsequently, as shown in FIG. 5C, a transparent electrode layer 6 as an upper electrode made of a ZnO:Al thin film is formed on the insulating layer 5, and each functional layer necessary for power generation using photoelectric conversion is formed. Using the provided solar cell substrate, a groove M2 for electrode separation that reaches the lower Mo electrode layer 2 is formed by scribing.

In the process of manufacturing the integrated thin-film solar cell described above, a laser scribing method and a mechanical scribing method have been used as techniques for grooving the grooves M1 and M2 for electrode separation.

In the laser scribing method, for example, as disclosed in Patent Document 1, a groove for electrode separation is formed by irradiating a laser beam emitted by exciting a Nd:YAG crystal with a continuous discharge lamp such as an arc lamp. .. In this method, when the groove is formed in the thin film solar cell substrate after the light absorption layer is formed, the photoelectric conversion characteristics of the light absorption layer 3 may be deteriorated by the heat of the laser light during scribing.

The mechanical scribing method is, for example, disclosed in Patent Documents 2 and 3, while pressing a blade end of a groove processing tool such as a metal needle (needle) having a tapered tip against a substrate by applying a predetermined pressure. This is a technique for processing a groove for electrode separation by moving it.

JP, 11-31815, A JP-A-2002-94089 JP, 2004-115356, A

In the mechanical scribing method as disclosed in Patent Documents 2 and 3, the shape of the cutting edge of the groove machining tool is made into a tapered needle shape, but strictly speaking, the contact area of the portion pressed against the thin film solar cell has a contact area. The tip is cut substantially horizontally so that it is flat to make it wider. That is, as shown in FIG. 6, the tip portion has a tapered truncated cone shape. While pressing the groove processing tool 8'having such a shape against the thin film (various functional layers such as the upper and lower electrodes and the light absorption layer) on which the groove of the thin film solar cell substrate is to be formed, it is moved in the Y direction along the planned scribe line. Groove processing is performed by relatively moving.
By using a grooved tool having a truncated cone shape with a tapered tip, groove processing can be performed relatively stably. On the other hand, as shown in FIG. 7, the thin film may be peeled off irregularly to a large extent, and even a portion that does not need to be removed may be removed, resulting in a problem that the performance and yield of the solar cell are reduced. It was

Therefore, the present invention, when processing the groove in various functional layers such as the light absorption layer and the electrode film in the thin-film solar cell substrate, good yield, and also suppress the deterioration of the product performance such as photoelectric conversion efficiency. An object of the present invention is to provide a groove processing tool for a thin film solar cell that can be processed, a groove processing method and a groove processing apparatus using the groove processing tool.

The groove processing tool for a thin-film solar cell of the present invention made to solve the above-mentioned problems is composed of a rod-shaped body and a truncated cone-shaped cutting edge region formed at the tip of the body, and the cutting edge region is a bottom surface. The base has a side surface extending from the bottom surface toward the body, a corner formed by the bottom surface and the side surface forms a cutting edge, and a groove is formed on the side surface from the bottom surface toward the body.
Further, the groove processing method of the thin film solar cell according to the present invention made to solve the above problems, along the scribe scheduled line of the thin film solar cell substrate, while pressing with the blade edge of the groove processing tool, the solar cell substrate and A groove processing method for an integrated thin-film solar cell, which comprises relatively moving a groove processing tool to form a scribe line in a thin film of a solar cell substrate, wherein the groove processing tool of the present invention is used to remove a bottom surface of the groove processing tool. Groove processing is performed by pressing on the surface of the thin film solar cell substrate.
Further, a groove processing apparatus for a thin-film solar cell according to the present invention made to solve the above-mentioned problems, a groove processing tool of the present invention, a table on which a solar cell substrate is mounted, and a bottom surface of the groove processing tool A scribe head that scribes while pressing the surface of the solar cell substrate is provided.

According to the groove processing tool of the present invention, since the groove portion is formed on the side surface of the blade edge region from the bottom surface pressed against the thin film solar cell substrate toward the body, the thin film allowed from the substrate is separated at the groove portion. Since it is difficult to peel off as a large lump, the influence of the removed thin film can be suppressed, and a scribe line with less film peeling can be formed.

(Means and effects for solving other problems)
The groove processing tool preferably has a bottom width of 30 μm or more and 100 μm or less.

The groove processing tool preferably has a groove width of 6 μm or more and 20 μm or less.

The grooving tool is preferably made of cemented carbide or diamond.
As a result, the tool has a long life and little deformation, so that scribing can be performed accurately for a long time.

The perspective view which shows one Embodiment of the groove|channel processing apparatus of the integrated thin film solar cell concerning this invention. The perspective view of the grooving tool concerning this invention. An enlarged bottom view of the groove processing tool. FIG. 3 is an enlarged view of a cutting edge region of the groove machining tool according to the present invention. The schematic diagram which shows the manufacturing process of a general CIGS type|mold thin film solar cell. The perspective view which shows an example of the conventional groove processing tool. The figure which shows the example of the processing state by the conventional processing tool.

Hereinafter, details of the present invention will be described in detail with reference to the drawings showing an embodiment thereof.
FIG. 1 is a perspective view showing an embodiment of an integrated type thin film solar cell scribing apparatus using a groove processing tool according to the present invention. The scribing device is provided with a table 18 which is movable in the horizontal direction (Y direction) and rotatable by 90 degrees and an angle θ in the horizontal plane, and the table 18 substantially forms a holding means for the solar cell substrate W. To do.

A bridge 19 composed of support columns 20, 20 on both sides of the table 18 and a guide bar 21 extending in the X direction is provided so as to straddle the table 18. The holder support 23 is movably attached along the guide 22 formed on the guide bar 21, and moves in the X direction by the rotation of the motor 24.

The holder support 23 is provided with a scribing head 7, and below the scribing head 7, a groove processing tool 8 for scribing the thin film surface of the solar cell substrate W placed on the table 18 is held. A holder 9 is provided.

Cameras 10 and 11 are provided on pedestals 12 and 13 that can move in the X and Y directions, respectively. The pedestals 12 and 13 move on the support 13 along a guide 15 extending in the X direction. The cameras 10 and 11 can be manually moved up and down, and the focus of imaging can be adjusted. The images captured by the cameras 10 and 11 are displayed on the monitors 16 and 17.

An alignment mark for identifying a position is provided on the surface of the solar cell substrate W placed on the table 18, and the position of the solar cell substrate W is detected by capturing the alignment mark with the cameras 10 and 11. Adjust. Specifically, the alignment marks on the surface of the solar cell substrate W supported by the table 18 are imaged by the cameras 10 and 11 to specify the positions of the alignment marks. Based on the position of the specified alignment mark, the displacement of the surface of the solar cell substrate W during mounting is detected, and the displacement is corrected by rotating the table 18 by a predetermined angle.

Every time the table 18 is moved in the Y direction at a predetermined pitch, the scribe head 7 is lowered to move in the X direction while the blade edge of the groove forming tool 8 is pressed against the surface of the solar cell substrate W. The surface of W is scribed along the X direction. When scribing the surface of the solar cell substrate W along the Y direction, the table 18 is rotated by 90 degrees and the same operation as described above is performed.

2, 3 and 4 are schematic views showing the groove processing tool 8 used in the present invention. 2 is a perspective view seen from below, FIG. 3 is an enlarged view of the bottom surface of the groove machining tool 8 seen from the bottom side, and FIG. 4 is an enlarged view of the cutting edge region of the groove machining tool 8 seen from the side surface side. Is. The groove forming tool 8 is composed of a cylindrical body 81 that substantially serves as a mounting portion for the scribe head 7, and a truncated cone-shaped cutting edge region 82 that is integrally formed at the tip portion of the body 81. Made of hard material such as alloy or diamond. The cutting edge region 82 includes a bottom surface 83 and a side surface 84 that rises from the outer edge of the bottom surface 83 toward the body 81. The corner portion formed by the bottom surface 83 and the side surface 84 becomes the cutting edge 85. Further, on the side surface 84, a groove portion 86 extending from the bottom surface 83 toward the body 81 is formed.

The width W of the bottom surface 83 is preferably 50 to 80 μm, but can be 30 to 100 μm in accordance with the required groove width of the scribe. The width of the groove 86 is preferably 6 to 20 μm, the depth is 3 to 10 μm, and the height H is preferably 30 μm or more. Further, the angle formed by the side surfaces 84 facing each other with the center of the blade edge region therebetween, that is, the apex angle α of the cone formed by extending the side surface 84 is preferably 20° to 70°. Further, the diameter of the cylindrical body 81 is preferably about 2-4 mm. The body 81 of the groove forming tool 8 is not limited to the columnar shape, but may be formed in a quadrangular or polygonal cross section.

When processing is performed using the groove processing tool 8 described above, it is attached to the scribe head 7 so that the bottom surface 83 of the blade edge region 82 is parallel to the surface of the solar cell substrate W. Further, the groove portion 86 is arranged so as to be located in front of the moving direction of the tool.

According to the present invention, since the groove portion 86 is formed in the cutting edge region 82, in the groove portion 86, the direction and the position of the force applied to the thin film to be removed are different from those of the other side surfaces 84. It is divided at the position of 86 and is not separated as a large lump. As a result, the size of the lump of the film to be peeled off becomes small, and the influence of the removed thin film becomes small, so that the scribe line with less film peeling can be formed.

In the above-described embodiment, the scribing process is performed by moving the scribing head 7 in the X direction, but it is sufficient if the scribing head 7 and the solar cell substrate W can move relatively. The scribe head 7 may be moved in the X direction or the Y direction in a fixed state, or only the solar cell substrate W may be moved in the X direction or the Y direction without moving the scribe head 7.

Although the representative embodiments of the present invention have been described above, the present invention is not necessarily limited to the structures of the above embodiments. It is possible to appropriately modify and change within the scope which achieves the object and does not deviate from the scope of claims.

INDUSTRIAL APPLICABILITY The present invention can be applied to a groove processing tool, a groove processing method, and a groove processing apparatus that can be used for manufacturing a thin film solar cell.

W Solar Cell Substrate 7 Scribing Head 8 Grooving Tool 81 Body 82 Blade Edge Region 83 Blade Edge Region Bottom 84 Blade Edge Region Side 85 Blade Edge 86 Groove

Claims (6)

It consists of a rod-shaped body and a frustoconical cutting edge area formed at the tip of the body,
The cutting edge region has a bottom surface and a side surface extending from the bottom surface toward the body,
The corner formed by the bottom surface and the side surface forms a cutting edge,
A groove machining tool for a thin film solar cell, wherein a groove is formed on the side surface from the bottom surface toward the body. The groove machining tool according to claim 1, wherein the bottom surface has a width of 30 μm or more and 100 μm or less. The groove machining tool according to claim 1, wherein the width of the groove is 6 μm or more and 20 μm or less. The grooving tool according to claim 1, wherein the grooving tool is formed of cemented carbide or diamond. A thin film solar forming a scribe line in the thin film of the thin film solar cell by relatively moving the thin film solar cell and the groove processing tool while pressing the cutting edge of the groove processing tool along the planned scribe line of the thin film solar cell. A method for machining a groove in a battery,
The groove processing tool is
It consists of a rod-shaped body and a frustoconical cutting edge area formed at the tip of the body,
The cutting edge region has a bottom surface and a side surface extending from the bottom surface toward the body,
The corner formed by the bottom surface and the side surface forms a cutting edge,
A groove is formed on the side surface from the bottom surface toward the body,
A groove machining method for a thin film solar cell, comprising: pressing the bottom surface of the groove machining tool against a surface of a thin film of the thin film solar cell to perform the groove machining. It consists of a rod-shaped body and a frustoconical cutting edge area formed at the tip of the body,
The cutting edge region has a bottom surface and a side surface extending from the bottom surface toward the body,
The corner formed by the bottom surface and the side surface forms a cutting edge,
A groove processing tool for a thin film solar cell in which a groove is formed on the side surface from the bottom surface toward the body, a table on which the thin film solar cell is mounted, and a bottom surface of the groove processing tool for forming a thin film of the solar cell. Grooving device equipped with a scribe head that performs grooving while being pressed against the surface of.