JP2001111078A - Manufacturing device of thin-film solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a processing focus of a laser beam just by a simple constitution. SOLUTION: In a manufacturing device for obtaining a thin-film solar cell by subjecting a thin film laminated on one side of a translucent insulating substrate 1 to the patterning with a laser beam 16 projected into the substrate 1 from the opposite side of the thin-film forming plane, a stage 14 where the substrate 1 is placed is constituted so as to support only a marginal part of the substrate, and a holding mechanism 100 which holds the substrate 1 placed on the stage 14 is arranged, thereby correcting deflection or warp of the substrate 1 placed on the stage 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an integrated thin-film solar cell manufacturing apparatus.

[0002]

2. Description of the Related Art In general, a thin-film solar cell comprises a transparent conductive film, an amorphous semiconductor photoelectric conversion layer (hereinafter referred to as a photoelectric conversion layer), and a back electrode laminated in this order on a transparent insulating substrate such as glass. Each layer (thin film) is formed by a method such as thermal CVD, plasma CVD, or sputtering.

In general, an integrated thin-film solar cell forms a series connection pattern using a laser beam. The integrated structure is such that a transparent conductive film is formed in a strip shape on a light-transmitting insulating substrate, and a photoelectric conversion layer and a back electrode are sequentially stacked thereon. The transparent conductive film of a unit solar cell (unit cell) is formed by a procedure of forming a pattern of both electrodes and a photoelectric conversion layer so that the transparent conductive film has a structure in contact with the back electrode of an adjacent unit solar cell.

[0004] In the manufacture of the integrated thin-film solar cell as described above, patterning (dividing into strips) of a transparent conductive film formed on a light-transmitting insulating substrate is performed by using a laser beam from a YAG fundamental wave laser device. The light-transmissive insulating substrate is made to enter from the opposite side of the thin film forming surface, and the photoelectric conversion layer and the back electrode are patterned by using a laser beam from a YAG-SHG laser device in the same manner. It is made to enter. As described above, the reason why the YAG-SHG laser beam is used for patterning the photoelectric conversion layer and the back surface electrode is that the YAG-SHG laser beam (wavelength: 0.532) which is the second harmonic of the YAG fundamental wave laser is used.
μm) is that the transparent conductive film underlying the photoelectric conversion layer can be processed without damaging the transparent conductive film.

A YAG fundamental wave laser device, a YAG
The -SHG laser device has almost the same device configuration except that the oscillator and the optical system are respectively for YAG fundamental wave and YAG-SHG.

[0006]

By the way, in the production of a thin film solar cell, it is desirable to always keep the processing focus of the laser beam appropriately in order to perform the patterning with the laser beam in a stable state. However, in practice, a light-transmitting insulating substrate such as a glass substrate has variations in thickness and warpage, and furthermore, the larger the area of the light-transmitting insulating substrate is, the greater the deflection of the substrate becomes. It is not easy to keep the processing focus at an appropriate value.

In the manufacture of a thin-film solar cell, a stage having a structure that supports only the periphery of the transparent insulating substrate is used in order to prevent the stage supporting the transparent insulating substrate from being damaged by laser beam irradiation. However, even if such a stage is used, the portion supporting the periphery of the transparent insulating substrate will be damaged by the laser beam, and the mechanical accuracy of the supporting portion will not be maintained. The focus problem still remains. In addition, when supporting only the peripheral portion of the transparent insulating substrate, if the size of the transparent insulating substrate increases, the transparent insulating substrate bends,
Or, it warps, and it becomes impossible to obtain a proper processing focus of the laser beam.

Here, in the manufacture of a thin-film solar cell, a thin film patterned by a laser beam scatters as a processing residue. This processing residue is very fine dust. Leaving it as it is degrades the working environment, and the processing residue adversely affects equipment and products including the optical system of the laser device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a thin-film solar cell manufacturing apparatus provided with a mechanism capable of always keeping the processing focus of a laser beam appropriately.

[0010]

According to the manufacturing apparatus of the present invention, a thin film laminated on one surface of a light-transmitting insulating substrate is patterned by a laser beam incident on the light-transmitting insulating substrate from the side opposite to the thin film forming surface. A manufacturing apparatus for obtaining a thin film solar cell by using a stage that supports only the periphery of the light-transmitting insulating substrate and a holding mechanism that holds the light-transmitting insulating substrate placed on this stage in a flat state Characterized by

According to the manufacturing apparatus of the present invention, since the stage on which the transmissive insulating substrate is placed is configured to support only the peripheral portion of the substrate, it is possible to prevent the stage surface from being damaged by laser beam irradiation. . In addition, since a holding mechanism for holding the transparent insulating substrate in a flat state is provided, it is possible to correct bending and warping of the transparent insulating substrate placed on the stage, and to always obtain an appropriate processing focus. it can.

Here, in the holding mechanism used in the manufacturing apparatus of the present invention, it is preferable that a portion in contact with the transparent insulating substrate is made of a soft material such as a resin.

If the holding mechanism is provided with a height adjusting mechanism for adjusting the height for supporting the translucent insulating substrate, it is possible to obtain a processing focus with high accuracy.

In the manufacturing apparatus of the present invention, if a mask for blocking a laser beam is provided on the peripheral edge on the upper surface side of the light-transmitting insulating substrate placed on the stage, laser beam irradiation is inevitable. It is possible to prevent the portion, that is, the peripheral portion of the substrate of the stage, from being damaged. Further, in this case, if the peripheral portion of the light-transmitting insulating substrate is held by using a mask, the facility can be simplified.

In the manufacturing apparatus of the present invention, if a means (dust collector) for collecting the processing residue generated by the patterning of the laser beam from the lower side of the translucent insulating substrate is provided, the processing residue in the working area is provided. Scattering can be reduced.

[0016]

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

FIG. 1 is an external view of an integrated thin-film solar cell, and FIG. 2 is a schematic cross-sectional view of the thin-film solar cell. Hereinafter, a method for manufacturing a thin-film solar cell will be described with reference to FIGS. An example will be described.

First, a glass substrate (light-transmitting insulating substrate) 1 on which a transparent conductive film is formed in advance is used. On the glass substrate 1, a transparent conductive film 2 is formed on the entire surface of one side surface and the peripheral end surface of the glass plate, and the transparent conductive film 2 is patterned by using a YAG fundamental wave laser beam. A single groove 7 is formed (scribed) to divide the transparent conductive film 2 into a plurality of strips 10. Thereafter, the glass substrate 1 is washed with pure water to form the photoelectric conversion layer 3. The photoelectric conversion layer 3 includes an Hp layer, a Hi layer,
Layer, a Hn layer, and the total thickness is 100 nm to 60 nm.
It is about 0 nm.

Next, the photoelectric conversion layer 3 is formed using a laser beam.
Is performed to form a second groove 8. The second groove 8 is formed at a position separated from the first groove 7 by a predetermined distance with a width of about 50 μm to 100 μm. The laser beam used to form the second groove 8 is:
In order to avoid the influence on the transparent conductive film 2, an SHG-YAG laser beam or the like having good transparency to the transparent conductive film 2 is used.

After the above groove processing is completed, the transparent conductive film 4
And a back electrode 5 are formed. The transparent conductive film 4 is made of ZnO or ITO having low specific resistance and high translucency, and the back electrode 5 is made of Al which is a metal having high reflectivity.
And Ag are used. The thickness of the transparent conductive film 4 is 50
about 200 nm, and the thickness of the back electrode 5 is 500 nm.
〜1 μm.

Then, a resin layer to be the resist layer 6 is applied on the back electrode 5 with a thickness of several μm to several tens μm and dried in a drying furnace or the like. In applying the resist layer 6,
Adopt spray method, spin coater, etc. Next, using a SHG-YAG laser beam, the third groove 9 is moved to a position away from the second groove 8 by a predetermined distance, and
By forming with a width of about 0 μm to 100 μm,
An integrated thin-film solar cell having the structure shown in FIG. 2 is obtained. In addition,
In such a structure, the transparent conductive film 4 and the resist film 6
May be omitted.

Next, an embodiment of the manufacturing apparatus of the present invention is shown in FIG.
This will be described with reference to FIGS. The manufacturing apparatus of this example includes a laser oscillator 15 and a stage 1 on which the glass substrate 1 is placed.
4. an X table 12 and a Y table 13 for moving the stage 14 in a two-dimensional direction to perform a predetermined scribe;
The glass substrate 1 is mounted on a stage 14 with the thin film forming surface facing down, and a laser beam 16 from a laser oscillator 15 is applied to the glass substrate 1 while the glass substrate 1 is placed on the stage 14. , X table 12
By driving the Y table 13, the thin film laminated on the glass substrate 1 can be patterned.
In this example, a YAG fundamental wave laser device and a YAG-SHG laser device are used as the laser oscillator 15.

In FIGS. 3 to 6, the description of the mask mechanism and the like generally attached to the thin-film solar cell manufacturing apparatus is omitted.

The manufacturing apparatus of this embodiment is characterized by a structure for supporting the glass substrate 1. The details will be described below.

First, in this embodiment, as shown in FIG. 4, the stage 14 is provided with a hollow 14a to support only the peripheral edge of the glass substrate 1. Such a structure is employed because, when the surface of the stage 14 is irradiated with a laser beam, the stage material itself is damaged depending on the beam intensity, and the transparent conductive film 2 or the photoelectric conversion layer This is to prevent processing residues generated when patterning 3 (or the back electrode 5 or the like in addition thereto) from adhering to the surface of the stage 14 and impairing the smoothness of the stage surface.

Here, when the stage 14 is structured as shown in FIG. 4 so as to support only the peripheral portion of the glass substrate 1, when the size of the glass substrate 1 increases, the glass substrate 1 The bending 25 as shown by the chain line may occur, or the glass substrate 1 may be warped,
In such a state, an appropriate laser beam processing focus cannot be obtained. Therefore, in this embodiment, two holding mechanisms 100 are provided in the hollow 14 a of the stage 14.
Are provided, and the glass substrate 1 is
By correcting the deflection and warpage of the glass substrate 1 and keeping the glass substrate 1 in a flat state, an appropriate laser beam processing focus can be always obtained.

As shown in FIG. 6, the holding mechanism 100 is a combination of a leg 18, a substrate support 19 and a height adjusting screw 20.
The height from the bottom surface of the substrate 8 to the upper end of the substrate supporting portion 19, that is, the holding height of the glass substrate 1 can be finely adjusted. The holding mechanism 100 avoids the patterning portion by the laser beam and selects and installs a position where the laser beam 16 is not irradiated to the substrate support 19.

In the holding mechanism 100 having the above structure, the substrate support 19 is in direct contact with the transparent conductive film 2 or the film surface of the back electrode 5. There is a risk of damaging these thin film surfaces. If the thin film surface is damaged, it may adversely affect electrical characteristics such as generation of no electromotive force and may result in poor appearance. Therefore, a soft material that does not damage the thin film surface is used for the substrate support 19. There is a need. Specifically, a resin such as Teflon tetrafluoride is used. When the substrate support 19 made of Teflon tetrafluoride was used, it was possible to perform processing without damaging the thin film surface.

Here, in processing using a laser beam, a processing method in which oscillation of a laser oscillator is not stopped during processing in order to stably oscillate the laser beam is common. Similarly, processing is performed while maintaining the state in which the laser beam is oscillated.
Therefore, the laser beam is in an oscillating state even in the process of moving from the strip 10 to the strip 10, and the laser beam 16 is also applied to the periphery of the glass substrate 1, and the laser beam 16 is applied to the substrate periphery support 17 (FIG. 4) of the stage 14. The surface will be damaged. In order to prevent this, in the present embodiment, as shown in FIGS. 5 and 6, masks 21 and 22 are provided to cover the peripheral edge of the upper surface of the glass substrate 1.

By providing the masks 21 and 22 in this manner, even if the laser beam advances toward the peripheral portion of the glass substrate 1, the progress is interrupted by the masks 21 and 22, so that the stage 14 The surface of the substrate peripheral supporting portion 17 is not damaged, and the laser beam processing focus is not affected.

In this example, the cylinders 23 are combined with the masks 21 and 22 so that the masks 21 and 22 are combined.
However, it is configured to function as a holder for holding down the peripheral edge of the glass substrate 1.

In the processing using the laser beam, the thin film patterned by the laser beam is scattered as fine processing residues 24 (see FIG. 6). Leaving it undesirably deteriorates the working environment and causes contamination of the optical system and the product, which is not preferable. Therefore,
In the present embodiment, as shown in FIG. 6, a dust collection duct 26 communicating with the center of the bottom of the hollow portion 14a of the stage 14 is provided.
Is installed, and a dust collector 27 is connected to the dust collection duct 26 to collect the processing residue 24 generated at the time of patterning. By such a dust collection system, the processing residue in the work area is removed. Scattering can be reduced.

[0033]

As described above, according to the apparatus for manufacturing a thin-film solar cell of the present invention, the stage on which the translucent insulating substrate is placed has a structure that supports only the peripheral portion of the substrate, and the stage has Since a holding mechanism that holds the placed translucent insulating substrate flat is provided, the processing focus of the laser beam can be kept at an appropriate value under a simple configuration, and stable patterning can always be realized. .

In the apparatus for manufacturing a thin-film solar cell according to the present invention, if the holding mechanism is provided with a height adjusting mechanism for adjusting the height for supporting the translucent insulating substrate, a highly accurate processing focus can be obtained. Obtainable.

In the apparatus for manufacturing a thin-film solar cell according to the present invention, if a mask for blocking a laser beam is provided at the peripheral edge on the upper surface side of the light-transmitting insulating substrate placed on the stage, the peripheral edge of the substrate of the stage can be provided. Damage to the support can be prevented. Further, in this case, if the peripheral portion of the light-transmitting insulating substrate is held by using a mask, the facility can be simplified.

In the apparatus for manufacturing a thin-film solar cell according to the present invention, if processing residue generated by laser beam patterning is configured to be collected from the lower side of the light-transmitting insulating substrate, processing in the work area can be performed. Scattering of the residue can be reduced, whereby the working environment can be preserved, and adverse effects due to the adhesion of the processing residue to equipment and products can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view (A) and a side view (B) showing the appearance of an integrated thin-film solar cell.

FIG. 2 is a cross-sectional view schematically illustrating the structure of an integrated thin-film solar cell.

FIG. 3 is a perspective view schematically showing a main structure of the embodiment of the present invention.

FIG. 4 is a perspective view schematically showing a structure of a stage used in the embodiment of the present invention.

FIG. 5 is a perspective view schematically showing a mask applied to the embodiment of the present invention.

FIG. 6 is a cross-sectional view schematically showing a structure of a stage used in the embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 glass substrate (translucent insulating substrate) 2 transparent conductive film 3 photoelectric conversion layer (amorphous semiconductor photoelectric conversion layer) 4 transparent conductive film 5 back electrode 6 resist 7 open groove 8 open groove 9 open groove 10 strip 11 mount 12 X table 13 Y table 14 Stage 15 Laser oscillator 16 Laser beam 17 Substrate peripheral support 100 Holding mechanism 18 Leg 19 Substrate support 20 Height adjusting screw 21, 22 Mask 23 Cylinder 24 Processing residue 25 Flexure 26 Dust collector 27 Dust collector

Claims (6)

[Claims] An apparatus for manufacturing a thin-film solar cell by patterning a thin film laminated on one surface of a light-transmitting insulating substrate with a laser beam incident on the light-transmitting insulating substrate from the side opposite to the thin-film forming surface. An apparatus for manufacturing a thin-film solar cell, comprising: a stage that supports only a peripheral portion of a light-insulating substrate; and a holding mechanism that holds the light-transmitting insulating substrate placed on the stage in a flat state. . 2. The thin-film solar cell manufacturing apparatus according to claim 1, wherein the holding mechanism has a portion in contact with the thin-film forming surface of the light-transmitting insulating substrate made of a soft material. 3. The thin-film solar cell according to claim 1, wherein the holding mechanism is provided with a height adjusting mechanism for adjusting a height at which the transparent insulating substrate is held. manufacturing device. 4. The mask according to claim 1, wherein a mask for blocking a laser beam is provided on a peripheral edge of an upper surface side of the light-transmitting insulating substrate placed on the stage. Equipment for manufacturing thin-film solar cells. 5. The thin-film solar cell manufacturing apparatus according to claim 4, wherein a peripheral portion of the light-transmitting insulating substrate is held by the mask. 6. The thin-film solar cell manufacturing apparatus according to claim 1, further comprising means for collecting processing residues generated by laser beam patterning.