JPH0982993A - Thin film processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to accurately detect the position of the edge of a board so as to continuously laser process the position of a predetermined distance from the edge of the board of a thin film formed on a flexible board at the time of conveying the board. SOLUTION: A board 1 is conveyed along the columnar surface of a position detecting roll 4 having a lower surface reflectivity than that of the vicinity of the edge of the board, and the position of the edge of the board is detected from the difference of the reflectivity by a reflection type photosensor 5. A laser beam 6 is moved in the lateral direction of the board corresponding to the detected position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film processing apparatus for processing a thin film formed on a flexible substrate while transporting the substrate roll-to-roll.

[0002]

2. Description of the Related Art An amorphous semiconductor thin film formed by glow discharge decomposition of a raw material gas or photo CVD can be formed by a vapor phase growth method, and thus it is easy to increase the area and the formation temperature is low. Therefore, it has a feature that it can be formed on a flexible substrate such as a resin film. A thin film solar cell is a typical thin film device using the amorphous semiconductor.

The thin film solar cell has an excellent feature that a series connection structure can be easily formed in a substrate as compared with a crystalline solar cell. A series connection structure of thin-film solar cells known in Japanese Patent Laid-Open No. 6-342924 discloses a thin-film solar cell laminate including a first electrode layer, an amorphous semiconductor layer, and a second electrode layer on one surface of a substrate. A third electrode layer, which is a collector electrode, is formed on the opposite surface, and the third electrode layer is electrically connected to the first electrode layer and the second electrode layer through holes formed in the substrate, and a thin film solar cell is formed by a laser processing method. The laminated body and the third electrode layer are divided into a plurality of parts, and the first electrode layer of one unit solar cell is connected by connecting the second electrode layer and the third electrode layer of the adjacent unit solar cell. There is.

[0004]

The separation of a thin film on a flexible substrate for roll-to-roll transportation is performed by unwinding the thin film on the substrate transported at a constant speed by roll-to-roll transportation between an unwinding roll and a winding roll. The thin film is divided into a plurality of pieces in parallel with the substrate transfer direction by performing laser processing on a can roll located at. The number of divisions of the thin film depends on the number of laser beams irradiated on the can roll, and the pattern width depends on the interval between the laser beams. However, since the processing position is determined by the distance from the substrate edge, in order to perform processing parallel to the substrate transport direction, the substrate edge is continuously detected and the laser light emission position is always set as the edge. It is necessary to control them so that they are parallel to each other.

In the past, this position control was performed by detecting the edge of the substrate using a transmission type optical sensor in the space between the unwinding roll and the can roll. However, when a thin film is formed on the substrate at a high temperature, the edge of the substrate curls. Further, since the curl state also changes depending on the type and film thickness of the laminated film, the accurate edge of the substrate cannot be detected. An object of the present invention is to solve the above-mentioned problems, and to provide a thin film element manufacturing apparatus capable of accurately detecting the position of the edge portion of a substrate and processing parallel to the edge portion.

[0006]

In order to achieve the above object, the present invention provides a thin film formed on the surface of a flexible substrate which is conveyed in the longitudinal direction at a predetermined distance from the substrate edge. In a thin film processing apparatus that continuously processes points, a position detection roll that is rotatable by making contact with the substrate being conveyed in a cylindrical surface is installed, and the surface reflectance of this position detection roll is near the edge of the substrate. A sensor that is lower than the surface reflectance and detects the position of the substrate edge portion from the difference in the surface reflectance facing the position detection roll, and moves the processing means in the width direction of the substrate corresponding to the detected substrate edge position. It shall be equipped with a drive means. When the substrate passes along the cylindrical surface of the position detection roll that has a surface reflectance lower than the surface reflectance near the flexible edge of the substrate, the position of the edge of the substrate is determined from the difference in surface reflectance by the facing sensor. Can be detected. Since this position detection is performed with the substrate wound around the position detection roll surface, the influence of curl is small and accurate. Then, if the processing means is moved in the substrate width direction corresponding to this position,
The thin film can be processed continuously parallel to the substrate edge and at a distance from it. It is effective that the processing means is a laser light emitting optical system. Since the laser beam processing has high processing accuracy, it is necessary to set the processing position accurately. It is preferable that at least the surface of the substrate near the edge is covered with a metal film, and the surface of the position detection roll is made of a non-metal material. When a metal electrode layer is coated on the entire surface of a flexible substrate such as a thin-film solar cell, the difference in reflectance cannot be obtained even if a commonly used metal roll is used as a position detection roll, so the surface is A roll covered with a non-metallic material is used. It is preferable that the surface of the position detection roll is covered with an adhesive material that fixes dust generated during processing. By fixing the processing dust to the adhesive material, there is no problem due to the processing dust adhering to the surface of the thin film. The surface of the position detection roll, at least the surface layer is made of an adhesive material,
It may be covered by a belt that is movable while contacting the substrate. As a result, the adhesive material that comes into contact with the substrate is
Since it always has a fresh surface on which the processing dust does not adhere, the effect of removing the processing dust from the thin film surface increases, and there is no risk of the processing dust reattaching to the substrate. Further, it is preferable that the belt is circulated through a cleaning tank that removes dust generated by processing.
As a result, the processing dust is removed from the belt surface on which the processing dust has been fixed, and the belt can be reused. The belt may be formed by adhering a film made of an adhesive material onto a film made of a material from which the adhesive material is easily peeled off by using an adhesive. This eliminates the adhesion between the belts due to the adhesive material when the belts are wound.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention can be effectively applied to patterning of a thin film laminate or an electrode film, which is carried out by laser light processing for separating a thin film solar cell into unit solar cells. When the metal electrode film is deposited on the entire surface of the flexible substrate of the thin-film solar cell, a position detection roll whose surface material is rubber having a low surface reflectance is used. When the position detection roll has the function of removing machining dust, the surface material of the roll is adhesive rubber. A reflective optical sensor is used as a sensor for detecting the position of the edge of the substrate based on the difference in surface reflectance. Of course, the present invention can be similarly applied to thin film processing on a flexible substrate, which is performed other than the production of the thin film solar cell.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings in which common portions are given the same reference numerals. The thin film processing apparatus on the roll-to-roll transfer substrate shown in FIG. 1 includes a feed chamber 11, a processing chamber 12, and a winding chamber 13. The flexible substrate 1 is unwound from the core 21 of the feed chamber 11,
By changing the direction from the idle roll 22 and transporting it between the driving roll 23 and the pressing roll 24 as shown by an arrow 31, the core 25 of the winding chamber 13 is wound. The processing chamber 12 has a diameter 15 around which the substrate 1 is wound.
A 0 mm can roll 2, a laser light emitting optical system 3 facing it, a position detection roll 4 for detecting the edge position of the substrate 1, and a detection sensor 5 fixed at a position facing it are housed. The position detection roll 4 has a low reflectance surface made of rubber. 2 is a plan view of the substrate 1, and FIG. 3 is a sectional view taken along the line AA of FIG. The substrate 1 is a heat-resistant polyimide film having a thickness of 50 μm, a silver thin film as the first electrode layer 31 and a- as the photoelectric conversion layer 32 on one main surface.
A Si film and an indium oxide film as the second electrode layer 33 are laminated, and a silver layer as the third electrode layer 34 is formed on the other main surface. A series connection hole 35 is formed in the substrate to connect the third electrode layer 34 to the first electrode layer 31, and a current collecting hole 36 is formed in the substrate at intervals of 10 mm to connect to the second electrode layer 33. This device was operated as follows.

As shown in FIG. 2, a thin-film solar cell 10 in which a photoelectric conversion layer 32 and a second electrode layer 33 each having a predetermined outer shape are laminated at regular intervals on a first electrode layer 31 covering the entire surface of a substrate 1.
Are formed in plural. This substrate 1 is a thin film solar cell 1
The idle roll 2 up to the core 25 is pulled out from the top of the core 21 wound with the formation surface of 0 upward as shown by the solid line.
2. Roll-to-roll conveyance was performed at a constant speed using the drive roll 23 and the press roll 24. The edge portion of the substrate 1 that closely passes on the cylindrical surface of the elastic position detection roll 4 is
The detection electrode 5 detects the difference in reflectance between the high-reflectance surface of the first electrode layer 31 made of metal on the substrate 1 and the low-reflectance surface of the position detection roll 4, and the surface of the can roll 2 at the edge of the substrate 1. The displacement from the upper predetermined position is detected by the sensor 5 and the lead wire 5.
Measurement is performed via the sensor signal processing unit 51 connected in 2. Then, the output optical system 3 connected by the laser light source 62 and the optical fiber 63 by the rotation of the feed screw 61 by the displacement.
Is moved at a right angle to the transport direction of the substrate 1, and then the second electrode layer 33, the photoelectric conversion layer 32, and the first electrode layer 31 on the substrate 1 transported in the direction of the arrow 71 are processed by the laser beam 6. The patterning line 7 passing between the series connection hole 35 and the current collection hole 36 is formed. The thin film solar cell 10 is divided into unit solar cell elements by the patterning line 7. Next, as shown by the solid line, the core 25 wound with the formation surface of the thin-film solar cell 10 facing upward is moved to the position of the core 21 and pulled out as indicated by the dotted line, and roll-to-roll conveyance is performed. A patterning line for separating the third electrode layer on the back surface side is formed at a position separated by a predetermined dimension from. If the patterning line passes between the series connection hole 35 and the current collection hole 36 at a position not facing the patterning line 7 on the surface, the series connection structure of the unit solar cell elements is completed. The mounting surface of these solar cells is on the core 25 wound as shown by the dotted line. Furthermore, if the unit solar cells connected in series are connected by wiring on the substrate 1 and the flexible substrate 1 is appropriately cut, a thin film solar cell module having an arbitrary output can be obtained.

FIG. 4 shows an embodiment in which a mechanism for removing processing dust generated during laser processing is added. The position detection roll 4 used here is covered with a surface adhesive rubber 8 as shown in an enlarged view in FIG. The adhesive rubber 8 forms a low-reflectance surface, and also adheres the processing dust generated by the irradiation of the laser beam 6 to remove it from the surface of the substrate 1. However, in the adhesive position detection roll 4 used in this embodiment, the adhesive rubber 8 is covered with the processing dust in order to remove the processing dust, and the adhesive force is deteriorated. As a result, problems such as poor removal of processing dust and reduction of thin film separation resistance due to redeposition of processing dust on the insulating substrate become a problem. FIG. 6 shows an embodiment in which the problem is solved.

In FIG. 6, the surface of the position detection roll 4 is covered with an adhesive belt 81 which is unwound from the core 26 and wound onto the core 27. In the adhesive belt 81, as shown in FIG. 7, the adhesive layer made of the adhesive rubber 8 is adhered to the surface of the polyimide film 82 with the adhesive 83, so that the always clean adhesive surface of the adhesive rubber 8 contacts the surface of the substrate 1. To remove processing dust. In this way, the above-mentioned defective removal of the processing dust and the re-adhesion of the processing dust to the insulating substrate were prevented. Since the adhesive rubber 8 does not easily adhere to the polyimide film 82, the belts do not adhere to each other when the belt 81 is wound around the core 26 or 27. The adhesive belt 81 used in this embodiment is conveyed in one direction and is used up. In the embodiment shown in FIG. 8, this adhesive belt 8
1 can be continuously used.

In FIG. 8, the adhesive belt 81 is stretched between the position detection roll 4 and the cleaning roll 28.
By rotating the rolls 4 and 28, the adhesive belt 81 on which the processing dust adheres is dipped in the isopropyl alcohol-based cleaning liquid 91 in the cleaning tank 9, and the adhesive belt 81 is ultrasonically cleaned using the ultrasonic oscillator 92. Removes the processing dust adhering to. After that, a cycle mechanism is provided in which the adhesive belt 81 is dried by blowing warm air in the drying unit 93 to remove the processing dust again. This mechanism prevents defective removal of processing dust and re-adhesion of processing dust to the substrate, and at the same time, the adhesive portion of the position detection roll is regenerated.

[0013]

According to the present invention, when a thin film is formed on a substrate at a high temperature by detecting the position of the edge of the substrate from the difference in reflectance on a position detection roll having a lower surface reflectance than the substrate. It has become possible to solve the problem of curling at the edge of the substrate that occurs and to perform roll-to-roll transfer thin film processing with high accuracy. Also, by making the surface of the position detection roll sticky and performing position detection and processing dust removal with one roll, the device cost is reduced and the adhesive position detection roll due to processing dust is used by using an adhesive belt. It is also possible to take measures against the deterioration of the adhesive strength of and improve the reliability of processing performance.

[Brief description of drawings]

FIG. 1 is a sectional view of a thin film processing apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of a thin film solar cell substrate on which a thin film is formed by the thin film processing apparatus according to the embodiment of the present invention.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view of a thin film processing apparatus according to another embodiment of the present invention.

5 is an enlarged cross-sectional view of a position detection roll used in the apparatus of FIG.

FIG. 6 is a sectional view of a thin film processing apparatus according to another embodiment of the present invention.

7 is an enlarged cross-sectional view of an adhesive belt used in the device of FIG.

FIG. 8 is a sectional view of a thin film processing apparatus according to still another embodiment of the present invention.

[Explanation of symbols]

 1 flexible substrate 2 can roll 21, 25, 26, 27 core 23 drive roll 28 cleaning roll 3 laser light emitting optical system 31 first electrode layer 32 photoelectric conversion layer 33 second electrode layer 34 third electrode layer 4 position detection roll 5 Detection Sensor 6 Laser Beam 61 Feed Screw 62 Laser Light Source 7 Patterning Line 8 Adhesive Rubber 81 Adhesive Belt 9 Cleaning Tank 91 Cleaning Liquid 10 Thin Film Solar Cell 11 Feed Chamber 12 Processing Room 13 Winding Room

Claims (7)

[Claims] 1. A thin film processing apparatus for continuously processing a portion of a thin film formed on a surface of a flexible substrate transported in a longitudinal direction at a predetermined distance from a substrate edge portion, the substrate being transported. A position detection roll that is in contact with the cylindrical surface and is rotatable is installed, and the surface reflectance of this position detection roll is lower than the surface reflectance near the edge of the substrate. A thin film processing apparatus comprising: a sensor for detecting a position of a substrate edge portion based on a difference; and a driving means for moving the processing means in a width direction of the substrate corresponding to the detected substrate edge position. 2. The thin film processing apparatus according to claim 1, wherein the processing means is a laser light emitting optical system. 3. The thin film processing apparatus according to claim 1, wherein at least the surface of the substrate near the edge is covered with a metal film, and the surface of the position detection roll is covered with a non-metal material. 4. The thin film processing apparatus according to claim 1, wherein the surface of the position detection roll is covered with an adhesive material that fixes dust generated during processing. 5. The thin film processing apparatus according to claim 4, wherein at least the surface layer of the position detection roll is made of an adhesive material and is covered with a belt that is movable while contacting the substrate. 6. The thin film processing apparatus according to claim 5, wherein the belt is circulated through a cleaning tank for removing dust generated by processing. 7. The thin film processing apparatus according to claim 5, wherein the belt is formed by adhering a film made of an adhesive material onto a film made of a material from which the adhesive material is easily peeled off by using an adhesive.