WO2010103947A1

WO2010103947A1 - Grooving tool for thin film solar cell

Info

Publication number: WO2010103947A1
Application number: PCT/JP2010/053212
Authority: WO
Inventors: 正信曽山
Original assignee: 三星ダイヤモンド工業株式会社
Priority date: 2009-03-09
Filing date: 2010-03-01
Publication date: 2010-09-16
Also published as: JP2010207945A; TW201115752A

Abstract

Provided is a grooving tool for a thin film solar cell in which when a cutting edge is worn, it can be easily replaced with a new cutting edge without exchanging the grooving tool itself, and integrated thin film solar cells can be manufactured at a high yield. A plurality of cutter blade areas having cutting edges that are directed substantially in the tangential directions are spaced from one another at equal distances in the circumferential direction on the outer peripheral portion of a disc-like body (81) which is rotatably and fixably attached to a holder (9) of a scriber, wherein one of the cutting edges is used to form a groove.

Description

Grooving tool for thin film solar cells

The present invention relates to a groove processing tool for manufacturing a chalcopyrite compound integrated thin film solar cell.
Here, the chalcopyrite compound includes CIGS (Cu (In, Ga) (Se, S) ₂ ), CIS (CuInS ₂ ) and the like in addition to CIGS (Cu (In, Ga) Se ₂ ).

In a thin film solar cell using a chalcopyrite compound semiconductor as a light absorption layer, an integrated structure in which a plurality of unit cells are connected in series on a substrate is common.

A conventional method for producing a chalcopyrite compound-based integrated thin film solar cell will be described. FIG. 7 is a schematic diagram showing a manufacturing process of a CIGS thin film solar cell. First, as shown in FIG. 7A, a Mo electrode layer 2 serving as a plus-side lower electrode is formed on an insulating substrate 1 made of soda lime glass (SLG) or the like by sputtering, and then a light absorption layer is formed. A groove S for lower electrode separation is formed on the previous thin film solar cell substrate by scribing.

After that, as shown in FIG. 7B, a light absorption layer 3 made of a compound semiconductor (CIGS) thin film is formed on the Mo electrode layer 2 by vapor deposition, sputtering, or the like, and on that, for heterojunction. A buffer layer 4 made of a ZnS thin film is formed by a CBD method (chemical bath deposition method), and an insulating layer 5 made of a ZnO thin film is formed thereon. Then, with respect to the thin-film solar cell before forming the transparent electrode layer, the interelectrode contact groove that reaches the Mo electrode layer 2 by scribing at a position spaced apart from the lower electrode separation groove S in the lateral direction. M1 is formed.

Subsequently, as shown in FIG. 7C, 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. An electrode separation groove M2 reaching the lower Mo electrode layer 2 is formed by scribing, using the solar cell substrate provided.

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 a technique for groove-growing the electrode separation grooves M1 and M2 by scribing.

In the laser scribing method, as disclosed in, for example, Patent Document 1, a groove for electrode separation is formed by irradiating laser light emitted by exciting an Nd: YAG crystal with a continuous discharge lamp such as an arc lamp. . In this method, when a groove is formed on 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.

For example, as disclosed in

Patent Documents

2 and 3, the mechanical scribing method is performed by pressing a cutting edge of a groove processing tool such as a metal needle (needle) having a tapered tip against a substrate while applying a predetermined pressure. This is a technique for processing a groove for electrode separation by moving the electrode. At present, this mechanical scribing method is often performed.

Japanese Patent Laid-Open No. 11-31815 JP 2002-094089 A JP 2004-115356 A

Grooving tools used in conventional mechanical scribing methods, including those disclosed in Patent Document 2 and Patent Document 3, are configured in a shape in which one cutting edge is provided at the tip of the body. The groove processing tool having such a shape is attached and fixed to the holder of the scribing device, and the groove processing tool is pressed against the thin film solar cell and moved relatively along the planned scribe line so that the groove processing is performed. ing.
However, with a grooving tool formed with a single cutting edge, if the cutting edge wears or spills due to use, it must be removed from the holder and polished or replaced with a new one each time. Was troublesome.

SUMMARY OF THE INVENTION Therefore, a first object of the present invention is to provide a solar cell grooving tool that can be easily replaced with a new cutting edge without replacing the grooving tool itself when the cutting edge is worn. .

Further, in the mechanical scribing method disclosed in Patent Document 2 and Patent Document 3, the shape of the cutting edge of the grooving tool is a tapered needle shape, but strictly speaking, the portion pressed against the thin film solar cell The tip is cut horizontally to be flat to increase the contact area. That is, as shown in FIG. 8, the tip portion has a truncated cone shape with a tapered surface.
When the cutting edge is worn, it is economical if the grooving tool can be removed from the holder, polished and repaired, and reused, but if the tip has a truncated cone shape, the diameter of the cutting edge is reduced by polishing. Will change. In solar cell substrates, it is important to maintain the scribe line width constant to achieve the quality (photoelectric conversion efficiency, etc.) planned in the product design and to improve the quality uniformity (reproducibility). For this purpose, it is necessary to make the degree of peeling of the thin film constant.

Therefore, the present invention secondly provides a grooving tool for a thin-film solar cell that can be reused by maintaining a constant width of the scribe line by polishing even for a cutting edge that has already been worn. With the goal.

The groove processing tool for an integrated thin film solar cell of the present invention, which has been made to solve the above-mentioned problems, has a plurality of blades whose blade edges are directed in the tangential direction at the outer peripheral portion of the disc-shaped body with equal intervals in the circumferential direction. A plurality of the grooves, and the groove can be formed with any one of the blades.

In the grooving tool of the integrated thin film solar cell of the present invention, when the blade used is worn or spilled, the disc-shaped body is set so that the next new blade is at the grooving position. By rotating only the angle, the grooving tool itself can be easily replaced with a new blade without exchanging, and the complexity of the replacement work can be eliminated.

(Means and effects for solving other problems)
The blade is preferably provided with a notch having a blade surface along the radial direction on the outer peripheral surface of the body so that a corner formed by the outer peripheral surface of the body and the blade surface becomes a blade edge.
As a result, the cutting edge can be point-contacted with the substrate at the time of grooving, and the thin film can be peeled smoothly and smoothly, and a straight and clean scribe line can be formed.

Moreover, it is preferable that the left and right side surfaces of the tip portion of the blade of the grooving tool are formed by a pair of parallel surfaces.
As a result, when the blade tip is worn, there is no change in the horizontal width of the blade even if the top surface of the blade, that is, the outer peripheral surface of the body is polished. Can be maintained the same as before polishing, and when all the cutting edges are worn, they can be repaired and reused.

Moreover, it is preferable that the grooving tool is made of cemented carbide or diamond (sintered diamond (PCD) or the like).
As a result, the tool has a long life and little deformation, so that it can be accurately scribed over a long period of time.

The perspective view which shows one Embodiment of the scribing apparatus for integrated type thin film solar cells using the groove processing tool concerning this invention. The perspective view of the groove processing tool concerning this invention. The front view of the said groove processing tool. The side view of the said groove processing tool. The side view which shows the example of the usage condition of the said groove processing tool. The perspective view which shows another Example of the groove processing tool concerning this invention. The schematic diagram which shows the manufacturing process of a general CIGS type thin film solar cell. The perspective view which shows an example of the conventional groove processing tool.

Hereinafter, details of the present invention will be described in detail with reference to the drawings showing embodiments thereof. Initially, the whole structure of the scribe device which attaches the grooving tool of this invention is demonstrated.
FIG. 1 is a perspective view showing an embodiment of an integrated thin film solar cell scribing apparatus using a groove processing tool according to the present invention. The scribing device includes a table 18 that is movable in the horizontal direction (Y direction) and that can rotate 90 degrees and an angle θ in a horizontal plane. The table 18 substantially forms a means for holding the solar cell substrate W. To do.

The bridge 19 composed of the

support pillars

20 and 20 on both sides provided across the table 18 and the guide bar 21 extending in the X direction is provided so as to straddle the table 18. The holder support 23 is attached to be movable along a 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 scribe head 7. A grooving tool 8 for scribing the thin film surface of the solar cell substrate W placed on the table 18 is provided below the scribe head 7 (for details, see FIG. A holder 9 is provided for holding (described later). The holder 9 can adjust the attachment angle, and the angle between the groove processing tool 8 and the solar cell substrate W can be adjusted by adjusting the attachment angle. Further, the attached grooving tool 8 can be rotated by a certain angle (for example, 90 degrees). For example, a ratchet mechanism is employed, and the rotation direction of the attached blade is set to one direction, and the rotation is stopped at a position of a predetermined angle by the claw in the reverse direction.

The cameras 10 and 11 are provided on the

pedestals

12 and 13 that can move in the X direction and the Y direction, respectively. The

pedestals

12 and 13 move along a guide 15 extending in the X direction on the support base 14. The cameras 10 and 11 can be moved up and down by manual operation, and the focus of imaging can be adjusted. Images taken by the cameras 10 and 11 are displayed on the

monitors

16 and 17.

The solar cell substrate W placed on the table 18 has a scribe line or the like that is formed in the previous process and can be observed from the surface by each process. Therefore, when scribing the solar cell substrate W in each process, the scribe line formed in the previous process is used as a mark for specifying the scribe position. For example, when forming grooves for upper and lower electrode contacts on the solar cell substrate W in which the light absorption layer 3, the buffer layer 4 and the insulating layer 5 are formed on the scribed lower electrode layer (Mo electrode layer) 2, A scribe line formed on the electrode layer 2 is used as a mark for specifying a groove forming position. That is, the position of the solar cell substrate W is adjusted by imaging the scribe line formed on the lower electrode layer 2 by the cameras 10 and 11. Specifically, the scribe line formed on the lower electrode layer 2 is imaged with the cameras 10 and 11 by imaging the scribe line formed on the lower electrode layer 2 that can be observed from the surface of the solar cell substrate W supported by the table 18. Identify the location. Based on the position of the scribe line formed in the specified lower electrode layer, the position (scribe position) where the upper and lower electrode contact grooves are to be formed is determined, and the position of the solar cell substrate W is adjusted to determine the scribe position. adjust.

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

Next, the grooving tool according to the present invention will be described.
2 to 4 show a grooving tool 8 which is an example of the present invention. 2 is a perspective view, FIG. 3 is a front view, and FIG. 4 is a side view. The grooving tool 8 includes a plurality of four blade regions in the present embodiment at equal intervals in the circumferential direction on the outer periphery of a disc-shaped body 81 made of a hard material such as cemented carbide or diamond. 82 is provided.
The blade region 82 is provided with a notch 84 that forms a blade surface 83 along the radial direction of the body 81 on the outer periphery of the body 81, and a corner formed by the body outer peripheral surface and the blade surface 83 becomes the blade edge 85. It is formed as follows. Further, an attachment hole 86 for attaching to the holder 9 of the scribing device is provided at the center of the disc-shaped body 81, and the attachment is made to the holder 9 via the attachment hole 86 so as to be rotatable and fixed.

When attaching the grooving tool 8 to the holder 9, the blade edge 85 is arranged toward the traveling direction side with respect to the solar cell substrate W as shown in FIG. ing.

The left and right width L1 of the top of the blade region 82 is preferably 50 to 60 μm, but can be 25 to 80 μm corresponding to the required groove width of the scribe. The diameter of the disk-shaped body 81 is, for example, 1 to 20 mm, the thickness L2 is 20 μm to 1 mm, and the height H of the blade surface 83 is about 50 μm to 5 mm.

In the above configuration, when the grooving tool 8 is attached to the holder 9 and grooving is performed, the blade edge 85 is in line contact with the substrate W (line contact in the front-rear direction of the page in FIG. ), The thin film can be smoothly peeled off, and a straight and clean scribe line can be formed. Further, when the grooving tool 8 is attached, the blade edge 85 is attached to the substrate W in a posture in which the blade surface 83 of the blade region 82 is slightly inclined with respect to the substrate W as shown in FIG. It is possible to reliably make contact with the line contact and peel off the thin film with good sharpness.

Also, when the cutting edge 85 being used is worn or spilled, the disk-shaped body 81 is rotated and fixed so that the next new cutting edge becomes the groove machining part. In the case of the present embodiment, the number of blade regions 82 formed at equal intervals is four, and therefore the rotation angle when the position is changed to a new blade edge is 90 degrees. Thereby, it is possible to easily set a new cutting edge without exchanging the grooving tool, and it is possible to eliminate the complexity of the exchanging operation.

FIG. 6 shows another embodiment of the grooving tool according to the present invention, in which left and right side surfaces 82a and 82b of the tip portion including the cutting edge 85 of the blade region 82 are formed by a pair of parallel surfaces. Has been.
As a result, when the cutting edge 85 is worn, the top and bottom surfaces of the blade region 82, that is, the outer peripheral surface of the body 81, will not change in the horizontal width of the blade region 82. However, the scribed groove width can be kept the same as that before polishing, so that when the cutting edge is worn, it can be repaired and reused.

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

The representative embodiments of the present invention have been described above, but the present invention is not necessarily limited to the above-described embodiment structures. For example, the means for attaching the grooving tool 8 to the holder 9 may be any means as long as the grooving tool 8 can be sequentially rotated every predetermined angle and can be reliably fixed at the set position. Others The present invention can be appropriately modified and changed within the scope of achieving the object and without departing from the scope of the claims.

The present invention can be applied to a groove processing tool used in manufacturing an integrated thin film solar cell using a chalcopyrite compound semiconductor film.

W Solar cell substrate 8 Groove machining tool 81 Body 82 Blade region 83 Blade surface 84 Notch 85 Blade tip 9 Holder

Claims

A groove processing tool for an integrated thin-film solar cell in which a plurality of blade regions with blade edges facing in the tangential direction are provided at equal intervals in the circumferential direction on the outer peripheral portion of the disc-shaped body.
The grooving tool according to claim 1, wherein a notch having a blade surface along a radial direction is provided on the outer peripheral surface of the body, and a corner formed by the outer peripheral surface of the body and the blade surface is a cutting edge.
The grooving tool according to any one of claims 1 to 2, wherein the grooving tool is formed of cemented carbide or diamond.
The grooving tool according to any one of claims 1 to 3, wherein the left and right side surfaces of the tip portion of the blade region are formed of a pair of surfaces parallel to each other.