JPH04288881A - Method and device for manufacturing solar cell - Google Patents

Abstract

PURPOSE:To eliminate looseness of a substrate due to self-weight and thermal expansion and a uniform film to be formed on a tensioned surface by providing a tension means at an edge of a flexible substrate which is placed on a tray for giving a tension constantly. CONSTITUTION:A flexible substrate 11 is fixed to a periphery on a tray 10 by holding of a retention member which is screwed by a bolt and a tension is given to the flexible substrate 11 by a tension means 14 which is adjacent to the retention means. The tension means 14 is configured so that a hinge member which can be rocked freely is provided at a retention member at a side which is opposite to the retention member. The hinge member moves downward following loosening of the flexible substrate 11 is inclined and the move operates as a tension for pulling the edge of the flexible substrate 11 outward. The flexible substrate 11 is constantly in tensioned state and an amorphous silicon layer is formed while retaining the state constantly. After the film is formed, move is made to another film-forming chamber 1 but a uniform layer is formed by forming film on the flexible substrate 11 which is constantly in tensioned state.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to plasma CVD, sputtering, etc. for forming thin films by discharge, and relates to the production of thin film solar cells in which, for example, an amorphous silicon layer is deposited on a flexible substrate. .

0002

2. Description of the Related Art As a manufacturing apparatus for thin film solar cells, for example, Japanese Patent Publication No. 62-43554 discloses a substrate advancing system that continuously moves a strip-shaped substrate so as to continuously advance the substrate in the longitudinal direction of the substrate. and a first amorphous semiconductor layer along the travel path of the strip substrate to continuously glow discharge deposit a first amorphous semiconductor layer on one surface of the strip substrate that is continuously moving in the longitudinal direction under the control of the device and the advancement device. A first glow discharge deposition device having a first glow discharge deposition chamber provided in An apparatus for manufacturing a connected amorphous solar cell is disclosed, and it is further described that if the substrate is a metal or polymer, such as stainless steel or aluminum, it can be supplied from a semi-continuous source, such as a large roll.

[0003] Also, in Japanese Patent Application Laid-Open No. 62-25465,
For example, a thin film solar cell in which an amorphous silicon layer is deposited on the substrate while a tray carrying a rigid glass plate substrate is transported through a preheating chamber, reaction chambers for p-layer, i-layer, and n-layer, and a removal chamber in that order. A manufacturing apparatus is disclosed.

0004

[Problems to be solved by the invention] Japanese Patent Publication No. 62-435
The former described in Publication No. 54 is a highly productive roll-to-roll manufacturing device that uses a large-area flexible substrate. There is leakage between the deposition reaction chambers, making it difficult to manufacture highly efficient solar cells.Furthermore, if a problem occurs during continuous production, all the substrates in the line must be discarded, resulting in low yields. Ta.

In the latter method using the multi-chamber separation method disclosed in Japanese Patent Application Laid-Open No. 62-25465, the trays carrying the substrates are transported discontinuously and sequentially into the reaction chamber, so that the reaction chambers are completely partitioned, and unlike the former method, However, in up-deposition in which a flexible substrate is placed upside down on an open tray in a sputtering or vacuum deposition area in a film-forming area, or in vertical side-deposition, problems caused by the weight and thermal expansion of the substrate can be solved. There is a problem that it is difficult to form a uniform film over a large area due to loosening. Although the relaxation is resolved in the position, the vapor phase decomposition substances during film formation, such as falling particles or dust, may cause non-uniform film formation, pinholes, insulation due to particle entrainment, or short circuit phenomena. There was a problem.

[0006]

[Means for Solving the Problems] In view of the above problems, the present invention provides a method for manufacturing a thin film solar cell that can apply tension to a flexible substrate in a multi-chamber separation method and form a uniform film. With the aim of providing a thin film forming raw material gas and applying electric energy to the electrodes to cause discharge, a tray carrying a substrate is sequentially transported to each film forming chamber in a plasma state, and the substrate is heated. A method of manufacturing a solar cell in which a thin film is applied to an adhering surface, wherein a flexible substrate is placed on the tray, and a tensioning means is provided on the edge side of the substrate to apply tension to the substrate. A thin film forming raw material gas is introduced, electrical energy is applied to the electrodes to cause discharge, and a tray carrying a substrate is sequentially transported to each film forming chamber in a plasma state, and a thin film is formed on the adhered surface of the substrate. In the solar cell manufacturing apparatus, a flexible substrate is placed on the tray, a holding member for fixing the flexible substrate to an edge of the tray, and a holding member for fixing the flexible substrate to an edge of the tray, and a holding member for fixing the flexible substrate to an edge of the tray, and A solar cell manufacturing apparatus is provided that includes a tensioning means for applying tension to a flexible substrate.

The present invention can be applied not only to plasma CVD methods but also to sputtering methods and vacuum evaporation methods.
A flexible substrate is a metal plate made of stainless steel, aluminum, nickel, titanium, etc. with a thickness of about 10 to 100 μm,
Further, a polymer film having a thickness of approximately 1 μm to 1 mm is applicable, and is formed by up-deposition in which a flexible substrate is placed upside down on a tray.

[0008]

[Operation] The flexible substrate on the tray, which is transported into each film forming chamber with its peripheral edge fixed by a holding member, expands due to heating and the rise in atmospheric temperature during film forming, and loosens due to its own weight. By providing a tensioning means that applies tension to the substrate adjacent to the holding member, the tension is always maintained by offsetting the relaxation, and is uniform due to the tension following the temperature in the film forming area. Forms a thick film.

[0009]

Embodiments Hereinafter, embodiments of the present invention will be explained in detail based on the drawings. FIG. 1 shows a schematic cross-sectional view of the device of the present invention, FIG. 2 shows a plan view of the tray on which the flexible substrate is set in FIG. 1, and FIG. 3 shows a section A-A in FIG. 2. FIG. 4 is a cross-sectional view showing another embodiment.

P-layer, i-layer, and n-layer amorphous silicon are deposited on the substrate 11 in parallel reaction chambers (not shown) that can be isolated from each other. For example, the reaction deposition chamber 1 for the i-layer is An upper electrode 3 and a lower electrode 4 are arranged in parallel in a vacuum container surrounded by an outer wall 2, the upper electrode 3 is connected to a normal earth potential 5, the lower electrode 4 is connected to a negative potential of a high frequency power source 6, A pipe 7 for introducing source gas from the outside and an exhaust pipe 7' for maintaining a constant degree of vacuum are provided.

A roller conveyor 8 is disposed on both sides of the film forming area of the upper electrode 3 and the lower electrode 4, and the roller conveyor 8 is rectangular in shape and has an L-shaped peripheral cross section on the bottom surface. A flexible substrate 11 is placed on a hollow tray 10 with a roller groove 9 cut in contact with the roller conveyor 8. This makes it possible to run freely.

The flexible substrate 11 is fixed by holding a holding member 13 screwed onto the periphery of the tray 10 with bolts 18, and tension means 14 adjacent to the holding member are used to tighten the flexible substrate 11. The tensioning means is configured such that a swingable hinge member 15 is attached to the opposing holding member 13 on the opposite side thereof. The holding member 13 may be made into a rectangular shape to match the hollow tray 10, and a hinge member 15 may be provided on each side, or the two sides of the holding member 13 may be joined in an L shape, or each side may be independent. As the holding member 13, a hinge member 15 may be attached to the holding member 13.

As shown in FIG. 4, as another tensioning means 14, a U-shaped groove 16 is provided around the L-shaped cross section of the tray 10 that supports the edge of the flexible substrate 11, and a flexible groove is provided in the groove. A weight member 17 having a thickness that can be loosely fitted with the flexible substrate 11 interposed is provided, but the weight member 17 is connected to the four corners of the abutting portion of the groove 16 by bypassing the end portions without abutting each other. The flexible substrate 11 is easily fitted into the groove 16, and the peripheral edge of the flexible substrate 11 and the tray 10 are fixed by screwing the holding member 13 to the top portion 19 of the L-shaped cross section in advance with bolts 18 and holding the flexible substrate 13 therebetween.

The tension means such as the holding member 13, the hinge member 15, and the weight member 17 are preferably made of stainless steel, which is the same material as the tray 10. The operation of the present invention will be explained below.

A flexible substrate 11 is placed on the tray 10,
Subsequently, a swingable hinge member 15 is placed on the peripheral edge of the substrate.
The flexible substrate 1 is placed on a tray 10 on which a holding member 13 attached with a
1 is placed together with a tray 10 on a roller conveyor 8 connected to the film forming chamber 1 or a preheating chamber (not shown) disposed before and after the film forming chamber 1, or a take-out chamber, and drives the roller conveyor and guides the guide roller 12. Transport and move. When the flexible substrate 11 on the tray 10 reaches the film forming area between the upper and lower electrodes 3 and 4 of the film forming chamber 1, for example, a reactive gas is introduced from the pipe 7, and high frequency power is applied to the lower electrode 4 from the high frequency power source 6. In addition, when plasma is generated, the ambient temperature in the film-forming region rises, and the flexible substrate 11 expands and relaxes toward the hollow side of the tray 10. However, it is joined to the holding member 13 in a cantilevered manner and closes the hollow side of the tray 10. The hinge member 15, which can freely swing to the side, rotates and tilts downward following the relaxation of the flexible substrate 11, and its operation acts as a tension force that pulls the edge of the flexible substrate 11 outward. The flexible substrate is always in a tense state, and an amorphous silicon layer is formed while maintaining this state at all times. After the film is formed, it travels to another film forming chamber 1, and even in that room, another film is formed on the flexible substrate 11 which is always under tension, thereby forming a uniform layer.

In the tensioning means 14 shown in FIG. 4, a weight member 17 is fitted into a groove 16 provided at the periphery of the tray 10 via a flexible substrate 11. The depth is set to absorb the slack of the
As the weight member 17 descends in the groove 16 due to its own weight, it draws the peripheral edge of the flexible substrate 11 and tensions the relaxed flexible substrate 11.

The tensioning means 14 uses the weight of each of the hinge member 15 and the weight member 17 to apply tension, but instead of using its own weight, the tensioning means 14 uses a spring to apply tension, for example, the peripheral end of the tray 10. A spring material consisting of a plurality of springs is fixed to the edge and the edge of the flexible substrate 11 is held between the springs, or a spring material is used between the edges of the flexible substrate 11 covered on a flat member. A spring may be inserted to apply tension and then placed on the tray 10.

[0018] Although the above embodiment describes the plasma CVD method, it goes without saying that other sputtering methods and vacuum evaporation methods can also be applied.

[0019]

Effects of the Invention The present invention provides tensioning means at the edges of the flexible substrate placed on the tray to constantly apply tension, thereby eliminating the loosening of the substrate due to its own weight and thermal expansion. It is now possible to form a uniform film on a tense surface, and with the separation formation method, the weight of the substrate is reduced and the load on trays and roller conveyors is reduced, making it possible to create large-area, flexible, and more efficient solar cells. can be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a device of the present invention.

FIG. 2 is a plan view of the tray in which the flexible substrate is set in FIG. 1;

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a sectional view showing another embodiment.

[Explanation of symbols]

1... Film forming chamber 10... Tray
11... Flexible substrate 13... Holding member 14... Tensioning means
15... Hinge member 17... Weight member

Claims (2)

[Claims] [Claim 1] A thin film forming raw material gas is introduced, electric energy is applied to the electrodes to cause discharge, and a tray carrying a substrate is sequentially transported to each film forming chamber in a plasma state, and a thin film is formed on the adhering surface of the substrate. 1. A method for manufacturing a solar cell in which a flexible substrate is placed on the tray, and a tensioning means is provided on an edge side of the substrate. 2. A thin film forming raw material gas is introduced, electric energy is applied to the electrodes to cause discharge, and the trays carrying the substrates are sequentially conveyed to each film forming chamber in a plasma state, and a thin film is formed on the adhering surface of the substrate. In the solar cell manufacturing apparatus, a flexible substrate is placed on the tray, a holding member for fixing the flexible substrate to an edge of the tray, and a holding member for fixing the flexible substrate to an edge of the tray, and a holding member for fixing the flexible substrate to an edge of the tray, and 1. A solar cell manufacturing apparatus, comprising: a tensioning means for applying tension to a flexible substrate.