JPH08267265A - Thin film machining device - Google Patents

Abstract

PURPOSE: To increase utilizing efficiency of laser optical system by rotating the line connecting irradiating points in a prescribed angle in the case a thin film laminate body is machined by irradiating it on one line with plural laser beam. CONSTITUTION: A laser beam from an oscillator 1 is split into an output ratio of roughly 7:3 by a beam splitter 2 and adjusted to respective prescribed output by output regulators 81, 82 and guided to optical fibers 41, 42. Out of two laser beams 12, 13, the laser beam 12 having higher output is passed into a small diameter round slit 61 and the laser beam 13 having lower output is passed into a large diameter round slit 62 through a beam expander 5. Successively, a machining device is laid on a base board so that the arraying direction of condensing lenses 71, 72 is coincided with the machining direction, irradiation of laser beams 12, 13 is executed. Next, by shifting a machining device in traverse direction and overlapping the machining direction right under the arraying direction of condensing lenses 71, 72, as soon as a beam splitter 2 is moved, a beam splitter 3 having adverse splitting ratio is rentered in the optical path of laser beam 11.

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 used for separating and processing a thin film laminated on a substrate for manufacturing a thin film solar cell or the like.

[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, so that its area can be easily increased and its formation temperature is low. Therefore, it has a feature that it can be formed on a substrate having flexibility such as resin. A thin film solar cell is a typical thin film element using this amorphous semiconductor. The thin film solar cell is formed by forming a conductive film on an insulating substrate, and then sequentially stacking an amorphous semiconductor film and a conductive film. At least one of the conductive films is made into a transparent conductive film, and sunlight is incident from this transparent conductive film side. Conventionally, the extraction voltage has been set by dividing the thin film solar cell into a plurality of pieces and connecting the divided thin film solar cells in series.

2A and 2B show an example of a thin film solar cell submodule. FIG. 2A is a plan view and FIG. 2B is a sectional view taken along line AA of FIG. This submodule consists of three unit solar cells 20. Each unit solar cell 20 has an insulating substrate 21.
A first electrode 22 made of silver, an amorphous semiconductor layer 23 mainly composed of amorphous silicon, and a transparent second electrode layer 24 are laminated on top of this, and a current collecting electrode layer 5 printed in a comb shape thereon.
Are connected in series by the connection electrode 26 on the substrate 21. In order to form this same structure, it is necessary to separate the first electrode layer, the amorphous semiconductor layer, and the second electrode layer laminated on the substrate into a plurality of unit solar cells. To perform this separation process, first, the underlying first electrode layer 2
2, the amorphous semiconductor layer 23 and the second electrode layer 24 are formed by removing and separating a wide width of, for example, 100 μm by laser processing, and the portion of the first electrode layer 22 which has been widely removed and separated is removed. The amorphous semiconductor layer 23 and the second electrode layer 24 are separated and processed with a width of, for example, 50 μm by using a laser beam having a width narrower than that of the removal separation of the first electrode layer 21. The short circuit of the electrode layer was prevented. However, in such a separation process, the positions of the two laser processes must be aligned with high accuracy, and alignment is difficult.

In order to cope with such a problem, the method disclosed in Japanese Patent Application No. 6-51473 discloses two laser beams 31 having different processing laser output densities and laser processing diameters, as shown in FIG. , 32 are arranged on the straight line in the machining direction 33, the output density is high, and the machining diameter is, for example, 50 to 10.
The first electrode layer 22, the amorphous semiconductor layer 23, and the second electrode layer 24 are separated by a laser beam 31 having a small value of 0 μm, and the laser beam 32 having a low output density and a large processing diameter of, for example, 200 to 400 μm is applied to the first surface of the surface. The two-electrode layer 24 was widely removed.
As a result of performing such processing, the laser processing performed in two times can be performed only once.

[0005]

In order to perform the laser processing as shown in FIG. 3, for example, a laser optical system connected to one oscillator 34 shown in FIG. 4 included in the drawings attached to the above specification is used. That is, the laser light 35 emitted from one oscillator 34 is equally divided by the beam splitter 36 and guided to the optical fiber 37. One of the light emitted from the optical fiber 37 is guided to the condenser lens 38 as it is and the other is expanded. After being magnified by the lens 39, it is guided to the condenser lens 38. The former light can be used as the first laser light 31 in FIG. 3, and the latter light having a large beam diameter after passing through the expander lens 39 can be used as the second laser light 32.

However, in the case of performing separation processing using such an apparatus, after processing one patterning line, the substrate or the optical system is moved horizontally for processing the next patterning line and is moved vertically. However, there is a drawback in that the efficiency of using an expensive device is low, the processing takes a long time, and the productivity is not good, because it has to be returned to the position of the starting point of the processing.

An object of the present invention is to provide a thin film processing apparatus which eliminates the above-mentioned drawbacks and which has high utilization efficiency of a laser optical system and can improve productivity.

[0008]

In order to achieve the above-mentioned object, one of the present invention is to divide one laser beam into a plurality of light beams for a laminated body of thin films and process each divided light beam. In a thin film processing device that irradiates processing points arranged in a line in a direction to process all or part of the layers of the laminated body under predetermined conditions, the line connecting the irradiation points of each light beam is the processing of each light beam. It is possible to rotate a predetermined angle without changing the conditions. Therefore, a spectroscope that splits one laser beam into two beams with a predetermined ratio and a spectroscope that splits the laser beam into two beams with an inverse ratio of the predetermined ratio are alternated in the optical path of the original laser beam. It is preferable that the line connecting the irradiation points of the two light beams be rotatable by 180 °, by providing a mechanism for switching the light beams. A mechanism that moves the beam expander that is inserted into the optical path of one of the two light beams split from one laser beam into the optical path of the other light beam, and that is inserted into the optical paths of the two light beams. It is also possible to provide a mechanism for alternately replacing two slits having different opening diameters, and to rotate the line connecting the irradiation points of the two light rays by 180 °. An optical fiber is provided in the optical path from the single laser beam to the irradiation end of multiple beams, and the line that exists in the optical path ahead of this optical fiber and that connects the members arranged in a line is at an arbitrary angle. It is also effective to be rotatable. Another aspect of the present invention is a thin film processing apparatus for irradiating a plurality of light beams split from a single laser beam to a thin film stack to process all or part of the stack under predetermined conditions. Therefore, each of the divided light beams is applied to the same point.

[0009]

When a plurality of laser beams are irradiated on one line to process all or part of each layer of the thin film laminate under different conditions, the line connecting the irradiation points can be rotated by a predetermined angle. In this case, after the processing for one processing line is completed, it is possible to perform processing for processing lines in different directions by a predetermined angle without largely moving the optical system. If the line connecting the irradiation points is rotated by 180 °, it is possible to carry out the machining in and out, and if it is rotated by 90 °, the machining in the orthogonal direction can be carried out. To rotate by 180 °, replace the spectroscope that splits the two rays with different intensities with one with the opposite ratio, or move the beam expander that forms the two rays with different processing diameters and insert the slit. Change.
If there is a flexible optical fiber in the optical path of the divided light rays, the processing direction is changed by an arbitrary angle by rotating the connecting line of the members existing in the optical path ahead of that and being in line.

If a plurality of light rays to be processed under different conditions are applied to the same point, the processing direction can be changed arbitrarily by moving the irradiation point in an arbitrary direction.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a laser processing apparatus according to an embodiment of the present invention. This device includes a laser oscillator 1, a beam splitter 2, 3, two optical fibers 41, 42 for splitting two lights at a constant ratio, a beam expander 5 connected to one optical fiber 42, and two types of beam expanders. Slits 61 and 6 with caliber
Slit plate 6 with two openings and two condenser lenses 7
It consists of 1, 72. In addition, output regulators 81 and 82 that finely adjust the output of light that is split from the light beam 11 emitted from the oscillator 1 and enters the optical fibers 41 and 42 may be inserted. The beam splitters 2 and 3 have opposite light splitting ratios, and can be alternately switched to the optical path of the light beam 11. The slit plate 6 has two large slits 61.
One, a small aperture 62 is opened, the light beam 12,
The diameters of the slits entering the optical path of 13 can be interchanged.

FIGS. 5 (a) and 5 (b) are thin-film solar cell modules manufactured according to an embodiment of the present invention using the apparatus of FIG. 1, (a) is a plan view, and (b) is (a). 3 is a cross-sectional view taken along line BB of FIG. 2, and the same parts as those in FIG. 2 are denoted by the same reference numerals. This solar cell was configured by sequentially forming a first electrode layer 22, an amorphous semiconductor layer 23, a second electrode layer 24, and a printed electrode 25 on a flexible polyimide film substrate 21. In order to form a series connection of the thin film solar cells, the first electrode layer, the amorphous semiconductor layer, and the second electrode layer were processed using the laser processing device shown in FIG. YA for processing
The second harmonic of the G: Nd laser is used to split the laser beam emitted from the oscillator 1 using the beam splitter 2 for splitting the output ratio to 7: 3, and the split laser beam is output to the output adjusters 81 and 82. Each of them is adjusted to a predetermined laser output and guided to the optical fibers 41 and 42. Of the two laser beams 12 and 13 emitted from the optical fiber, the laser beam 12 having a high output is passed through the small-diameter circular slit 61 having a diameter of 0.5 mm, and the laser beam 13 having a low output is transmitted to the beam expander 5
And pass through a large-diameter circular slit 62 having a diameter of 2.0 mm.
Then, the processing direction 2 is set in the arrangement direction of the condenser lenses 71 and 72.
A processing device is arranged on the substrate so that 7 coincide with each other, and the laser beams 12 and 13 are moved and irradiated in the processing direction. Then, the laser beam 12 having a high processing output and a small diameter is scanned to process and remove the first electrode layer 22, the amorphous semiconductor layer 23, and the second electrode layer 24, and the laser beam 13 having a low processing output and a large diameter is used. Then, the second electrode layer 24 alone is processed by scanning. By performing such processing, it is possible to prevent electrical contact between the first electrode layer 22 and the second electrode layer 24 due to the laser-processed end portion. Next, the processing device is laterally displaced with respect to the substrate without changing the orientation of the substrate, and the condenser lens 71,
The processing direction 28 is made to overlap immediately below the arrangement direction of 72, and the beam splitter 2 is moved to the position of the dotted line in the direction of arrow 91, and at the same time, the beam splitter 3 having the opposite division ratio is put in the optical path of the laser beam 11. In conjunction with this, the beam expander 5 and the slit plate 6 are moved in the direction of the arrow 92, and the diameters of the light rays 12 and 13 immediately before the slit plate 6 and the position diameters of the circular slits 61 and 62 are also reversed from the conventional machining. . By performing the processing in the opposite processing direction 28 in this manner, the same processing as the processing in the processing direction 27 can be performed, and the thin film solar cell according to the difference in the processing state when performing the return processing without changing the orientation of the substrate. Prevent the performance degradation of.

FIG. 6 shows a laser processing apparatus according to another embodiment of the present invention, in which the same parts as those in FIG. 1 are designated by the same reference numerals. In this device, instead of using the two beam splitters 2 and 3, the flexibility of the optical fibers 41 and 42 is utilized, and the beam expander 5, the slits 61 and 62, and the condenser lens ahead of the optical fibers are used. The portions 10 of 71 and 72 were rotated as indicated by arrow 93 so that the processed state was always the same, and only one beam splitter 2 was used. By using this apparatus, not only the above-described return processing, but also the processing in any direction on the substrate, for example, in the direction orthogonal to the processing directions 27 and 28, can be performed by rotating the rotating portion 10 to 90.
It is possible by turning °.

FIG. 7 shows a laser processing apparatus according to still another embodiment of the present invention, and the same parts as those in FIGS. 1 and 6 are designated by the same reference numerals. In this device, two laser beams having different processing outputs and processing diameters are combined and irradiated. That is, the laser beam 11 emitted from the oscillator 1 contains YA
This laser beam 1 using the second harmonic of a G: Nd laser
1 is split using a beam splitter 2 that splits an output ratio of 7 to 3, and the split laser beams 12 and 13 are adjusted to predetermined laser outputs using output adjusters 81 and 82, respectively.
It leads to the optical fibers 41 and 42. The high power laser beam 12 emitted from the optical fiber 41 passes through the small diameter circular slit 61 having a diameter of 0.5 mm, and the low power laser beam 13 is
A large diameter circular slit 62 having a diameter of 2.0 mm is passed through. Finally, the laser beams 12 and 13 whose processing output and processing diameter have been adjusted are guided to the condenser lenses 71 and 72 arranged so that the two laser beams divided at the processing point overlap. By doing so, it is possible to perform processing in all directions depending on the moving direction of the processing point with respect to the substrate in the same processing state.

[0015]

According to the present invention, the laser beam for processing all or part of the layers of the thin film laminate under the respective processing conditions is formed by dividing the laser beam from one oscillator. When irradiating the processing points arranged on the line,
By making the line connecting the processing points rotatable, it became possible to perform processing in different directions under the same conditions without significantly moving the laminate or the optical system. As a result, patterning for manufacturing a thin-film solar cell can reduce the processing time by the return processing or the processing in the orthogonal direction, and the productivity is improved. Further, the same effect as above can be obtained by irradiating the same processing point with laser beams having different processing conditions.

[Brief description of drawings]

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

FIG. 2 shows a solar cell module that has been subjected to a conventional thin film processing method, (a) is a plan view, (b) is AA of (a).
Line cross section

FIG. 3 shows another conventional method for processing a thin film solar cell,
(a) is a plan view, (b) is a sectional view

FIG. 4 is a front view showing a thin film processing apparatus for performing the processing of FIG.

FIG. 5 shows a solar cell module manufactured using the thin film processing apparatus of the embodiment of the present invention, (a) is a plan view,
(b) is a sectional view taken along line BB of (a).

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

FIG. 7 is a front view showing a thin film processing apparatus of still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser oscillator 11, 12, 13 Laser beam 2, 3 Beam splitter 41, 42 Optical fiber 5 Beam expander 6 Slit plate 61, 62 Slit 71, 72 Condensing lens 10 Rotating part 20 Unit solar cell 21 Substrate 22 First electrode Layer 23 Amorphous semiconductor layer 24 Second electrode layer 27, 28 Processing direction

Claims (5)

[Claims] 1. A single laser beam is divided into a plurality of light beams for a thin film laminate, and the respective divided light beams are applied to processing points arranged in a line in the processing direction under predetermined conditions. In a thin film processing apparatus for processing all or part of layers of a laminated body, a line connecting irradiation points of each light beam can be rotated by a predetermined angle without changing processing conditions of each light beam. apparatus. 2. A spectroscope for splitting one laser beam into two beams at a predetermined ratio and a spectroscope for splitting two laser beams at a ratio opposite to the predetermined ratio are provided in the optical path of the original laser beam. 2. The thin film processing apparatus according to claim 1, further comprising a mechanism for alternately irradiating with each other, the line connecting the irradiation points of the two light rays being rotatable by 180 °. 3. A mechanism for moving a beam expander, which is inserted into the optical path of one of the two light beams split from one laser beam, into the optical path of the other light beam, and an optical path of the two light beams. 2. A mechanism for alternately replacing two slits each having a different opening diameter to be inserted into the optical fiber, and the line connecting the irradiation points of the two light rays can be rotated by 180 °.
Alternatively, the thin film processing apparatus described in 2. 4. An optical fiber is provided in each of optical paths leading to irradiation ends of a plurality of light beams split from one laser beam,
The thin film processing apparatus according to claim 1, wherein a line existing in the optical path ahead of the optical fiber and connecting the members arranged in a line is rotatable by an arbitrary angle. 5. A thin film processing apparatus for irradiating a plurality of light beams divided from one laser beam to a thin film laminate to process all or part of the layers of the laminate under predetermined conditions. A thin film processing apparatus characterized by irradiating each of the divided light beams to the same point.