JPS62205669A - Manufacture of thin film solar cell - Google Patents

Abstract

PURPOSE:To make it possible to ensure cutting of a layer to be machined, without giving effects to a lower layer, by contacting the tip part of an ultrasonic wave machining tool to the layer to be machined, relatively moving the tip part with respect to the layer to be machined, and cutting the layer. CONSTITUTION:An ultrasonic wave vibrator 51 comprising a piezoelectric element such as barium titanate is attached to a supporting body 7. The ultrasonic wave, which is generated by the vibrator 5, is converged at the tip part of a cutting tool 6 through a horn 52. A layer to be machined 10 on a solar cell substrate 1, to which said tip is contacted, is broken and separated with the energy of the ultrasonic wave. In the patterning of a metal layer, the metal layer comprising Al, Ag, Cu and the like can be cut with good selectivity without damaging an amorphous layer by adjusting the output of the ultrasonic wave vibrator 51 and a sweeping speed with respect to the substrate 1.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

In the present invention, a semiconductor thin film and a metal electrode layer are laminated on a plurality of transparent electrodes arranged in a row on a single translucent insulating plate, and each is divided by parallel cut parts and connected in series. The present invention relates to a method for manufacturing a thin film solar cell comprising a plurality of unit cells.

[Prior art and its problems]

Since the amorphous semiconductor film formed by glow discharge decomposition of raw material gas or photo-CVD is grown in a vapor phase, it is theoretically easy to increase the area, and it is expected to be used as a low-cost Ohma battery material. In order to efficiently extract the power generated from these amorphous solar cells, it is necessary to
It is desirable that t Tl has a shape as shown in FIG. 3, for example, and a structure in which unit cells are connected in series. In this structure, transparent electrodes 21, 22, 23, 24, . 33, 34..., then metal electrode 41
．． Form in the order of 42, 43°, 44... And the transparency of one unit cell? The patterns of both electrodes and the amorphous layer are configured so that Iti partially contacts the metal electrode of an adjacent unit cell. Laser scribing technology has recently come to be used to form such patterns. This has the advantage of reducing the number of patterning steps and reducing costs compared to the case of using conventional photoetching. In patterning using a laser scribe, first, a beam of focused light from a laser, usually a YAG laser, is swept over a transparent conductive film formed on the entire surface of the substrate 1, and a rectangular transparent mold i21.22.23 is formed. ... to form. An amorphous layer is formed on the entire surface, and then similarly divided by sweeping a focused laser beam to form strip-shaped amorphous i regions 31, 32, 33, . . . . Figure 4 shows a patterned transparent electrode 21.22°2
The figure shows a state in which amorphous Mi3 is deposited on the entire surface of the layer 3, and then a cut section 8 is formed. However, in this case, the laser output is too small to completely cut the amorphous layer 3 as shown in section A. A metal i-pole 42 is provided thereon.
is not connected to the transparent electrode 23, and the series connection of the unit cells is interrupted, so that no output is produced from the solar cell. In addition, if the laser output is too large, the transparent II1 electrode 24 will be cut as shown in part B, and the contact surface between the metal' electrode 43 and the transparent electrode 24 that will be formed later will become small, resulting in a low resistance. Unable to connect. On the other hand, when the metal layer 4 is formed on the entire surface of the patterned transparent electrode and amorphous layer as shown in FIG. 5, and the metal layer is divided using a YAG laser, the laser beam output is adjusted when cutting the amorphous layer. It is even more difficult than That is, if the laser output is too small, the metal layer 4 will not be completely cut and adjacent unit cells will be short-circuited as shown in section 0, and if the laser output is too large, the transparent mold 123 will be short-circuited as shown in section D. However, it is very difficult to find optimal conditions for the laser output so that only the metal layer 4 is cut. In addition, when the purpose is to produce rice, it is a major drawback that processing must be carried out while finding the optimum laser output for each solar cell device. Furthermore, if there are variations in the thickness or reflectance of the gold DX F5, there will be parts that cannot be cut even when swept with a laser of a constant output, or parts that will cut through the transparent N or crosspiece.

[Purpose of the invention]

The present invention solves the above-mentioned problems and facilitates the selection of cutting processing conditions for dividing the gold Y4 electrode layer or the semiconductor NIQ, and manufactures a thin film solar cell that can be performed at high speed, reliably, and at low cost. The purpose is to provide a method.

[Key points of the invention]

What is the present invention? At least one of the semiconductor thin film and the metal layer laminated on the transparent electrode of jf number, the tip of an ultrasonic machining tool connected to an ultrasonic vibrator is brought into contact with the layer to be processed, and the layer to be processed is The cutting is performed by relative movement, and the ultrasonic energy can reliably cut the 11th layer of wave power without affecting the underlying layer, so the above-mentioned objective is achieved. It is effective to form a strip-like pattern at a higher speed by arranging several ultrasonic machining tools in a line and simultaneously bringing them into contact with a liquid injection hole for cutting.

[Embodiments of the invention]

FIG. 1 shows an embodiment of the present invention, in which ultrasonic waves generated by an ultrasonic vibrator 51 made of a piezoelectric element such as barium titanate attached to a support 7 are transmitted to a cutting tool via a horn 52. It is focused at the tip of 6. The cutting tool 53 has a conical shape, and its tip contacts the layer 10 to be processed on the solar cell substrate 1. Amorphous layer or metal 1! The Tachibana layer is crushed, peeled off, and peeled off by ultrasonic energy. Therefore, by sweeping the support 7 or the substrate 1, a striped pattern of an amorphous layer or a metallic electrode layer is formed. The frequency of the ultrasonic transducer is several tens of kiloz to one hundred k11z
+By using a device with an output of several tens of W, it is possible to
A pattern with a width of m to several hundred μm can be cut at a speed of ten to several tens of cuts/second. 3rd in amorphous large lit pond
As shown in the figure, transparent electrodes 21 to 24 made of SnO□ or the like are formed on the glass substrate +Iix. The patterning can be easily performed by a laser scribing technique using a YAG laser or the like. However, when cutting the amorphous semiconductor layer formed thereon as shown in FIG. 4, it is necessary to ensure that the transparent electrode is not damaged and that no semiconductor layer remains. When using a laser, the laser output! Although If is difficult, according to the present invention, for example, an amorphous layer with a width of 100 μIn is easily crushed at a speed of 30 c+a/sec using an ultrasonic vibrator with a frequency of 20 kHz and an output of 10 W, f#IXM,
It has been found that divided amorphous layers 41 to 44 can be formed, and the transparent electrodes 21 to 24 made of 5nOtHJ or the like formed on the glass substrate 1 are not damaged by ultrasonic energy. Therefore, it is easy to selectively cut only the amorphous layer. As shown in FIG. 5, in the patterning of the metal layer 4 formed entirely on the upper right side of the amorphous semiconductor, the output of the ultrasonic transducer and the sweep speed with respect to the substrate are set under the same conditions as in the processing of the amorphous layer, based on the present invention. By adjusting to A1. All 1. Ag, Cu, etc. It was found that the i'i layer could be cut with good selectivity without damaging the underlying amorphous layer. If the output of the ultrasonic transducer is too large or the sweep speed is too slow, the underlying amorphous layer will also be cut at the same time, but even in this case, the transparent electrode will not be damaged as described above. , does not cause deterioration of solar cell characteristics. FIG. 2 shows another embodiment in which ultrasonic cutting tools 61, 62, 63, etc. as shown in FIG. Place it in
This figure shows a method of simultaneously patterning the dividing lines 81, 82, 83, . . . in - times of sweeps.

【Effect of the invention】

According to the present invention, semiconductor y of series-connected thin film solar cells
When patterning l films and metal TL pole layers, using an ultrasonic processing tool cuts semiconductor thin films and gold RF47FJ more easily than transparent conductive films, so we recommend using the conventional laser scribing method. Processing with better selectivity is now possible, and there is no risk of disconnection of unit cells. Cutting speed is several tens of cIa
/second is easily achieved and is comparable to the laser method. In addition, the ultrasonic machining tools themselves are not very expensive, and by arranging multiple ultrasonic machining tools in rows, low-cost machining can be achieved even by using a method that enables patterning in -1 sweeps. This gives you the advantage of

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing one embodiment of the present invention, Fig. 2 is a perspective view showing another embodiment, Fig. 3 is a cross-sectional view of an amorphous solar cell, and Figs. 4 and 5 are manufacturing steps thereof. FIG. 1: Thick V4 Ti Mk Base'tH151: [Sound 1ti
i+Jr child, 52: Horn, G, 61.62.63
:Ultrasonic cutting tool, 81.82゜Figure 1 B-'tr;rt*nll Engineer Figure 2

Claims (1)

[Claims] 1) A semiconductor thin film and a metal electrode layer are stacked on a plurality of transparent electrodes arranged in a row on a single transparent insulating substrate, and each is divided by parallel cut parts and arranged in series. In a method of manufacturing a solar cell comprising a plurality of connected unit cells,
A thin film solar cell characterized in that at least one of a semiconductor thin film and a metal electrode layer is cut by bringing the tip of an ultrasonic processing tool into contact with the layer to be processed and moving it relative to the layer to be processed. Production method. 2) A method for manufacturing a thin film solar cell according to claim 1, characterized in that a plurality of ultrasonic processing tools are arranged in a line and brought into contact with the layer to be processed at the same time to cut it.