JPH0680836B2 - Photovoltaic device manufacturing method - Google Patents

Description

The present invention relates to a method of manufacturing a photovoltaic device mainly used as a power source for a timepiece or the like.

[Technical background]

When a plurality of photovoltaic elements are externally connected in series, they are usually constructed as shown in FIG. Fig. 7 is a schematic plan view showing a conventional photovoltaic device, and Fig. 8 is VIII-VII in Fig. 7.
Is a cross-sectional view by the line I, an insulating substrate 21, which is formed by providing an insulating film made of a polymer compound on a substrate such as stainless steel,
A plurality of metal electrode layers 22a, 22 provided with extended portions 22p, 22q, 22r extending to the peripheral side of the insulating substrate 21 using a metal mask
b, 22c are formed with gaps 26ab, 26bc between them, and then these metal electrode layers 22a, 22b, 22c and the gaps 22ab,
A semiconductor layer 23 having a photoactive layer is laminated over 22bc, and further extended portions 24p, 24q, which extend to the peripheral side of the insulating substrate 21 by using a metal mask on the surface of the semiconductor layer 23, respectively.
The transparent electrode layers 24a, 24b, 24c having 24r are formed, and the extended portions 24p, 24q of the transparent electrode layers 24a, 24b are adjacent transparent electrodes 24b, 24.
The extended portions 22q and 22r of the metal electrode layers 22b and 22c located under c are overlapped. As a result, three photovoltaic elements sandwiching the common semiconductor layer 23 between the metal electrode layers 22a, 22b, 22c and the transparent electrode layers 24a, 24b, 24c are connected in series, and the metal electrode layer 22
A photovoltaic device having the extended portion 22p of a and the extended portion 22r of the transparent electrode layer 24c as terminals is manufactured.

By the way, in the conventional manufacturing method as described above, the metal electrode layers 22a, 22b, 22c, and the transparent electrode layers 24a, 24b, 24c are formed in a mode in which they are separated by using a metal mask, but a metal mask is used. In this case, the gaps 26ab, 26bc between the metal electrode layers 22a, 22b, 22c are about 0.3 mm, and the transparent electrode layers 24a, 24b,
It is unavoidable that the gap between 24c has a width of about 0.6 mm to prevent the material from wrapping around.

Such a gap is of course a major obstacle to increasing the effective area of the substrate.
For example, since it is used as a wristwatch electrode, when it is applied to a dial, there is a problem that the above-mentioned gaps between the photovoltaic elements are conspicuous, resulting in impairing the design effect of the timepiece itself.

[Prior art]

For this reason, conventionally, a method of separately forming a transparent electrode or the like by a photolithography method or a method of scribing with a laser beam after integrally forming in advance has been performed.

The specific contents of the case of using the scribing method using a laser beam are as shown in FIGS.

FIGS. 9 and 10 are schematic views showing a manufacturing process of a photovoltaic device when using a scribing method using a laser beam,
A metal electrode layer 32, a semiconductor layer 33, and a transparent electrode layer 34 are laminated in this order on an insulating substrate 31. Incidentally, the metal electrode layer 32,
The transparent electrode layer 34 has extended portions 32p, 32q, 32r, 32s, 34p, 34q, 34r, 34s extending at the peripheral side of the insulating substrate 31 at regular intervals.
Are formed respectively, and the extension portions 32p, 32q, 32r are overlapped with the adjacent extension portions 34q, 34r, 34s. Then, as shown in Fig. 10, the extension parts 32p and 34q, 32q and 34r, 32 which overlap each other are shown.
Between r and 34s, the metal electrode layer 32, the semiconductor layer 33, and the transparent electrode layer 34 were scribed by using a laser beam, and each was divided into four pieces to be directly connected to the four photovoltaic elements. Manufacture a photovoltaic device in the state.

[Problems to be solved by the invention]

By the way, among the conventional methods as described above, the photolithography method can reduce the gap between the photovoltaic elements to about 0.3 mm, but there is a problem that the number of manufacturing steps is large and an increase in product cost cannot be avoided. On the other hand, the laser scribing method has an advantage that the mutual gap can be set to about 20 to 100 μm, but on the other hand, the residue such as melt dripping formed during the processing contacts the metal electrode layer and the transparent electrode layer. In addition to forming a short circuit state, there is a problem that the semiconductor layer is annealed by the laser beam and this portion is crystallized or crystallized to form a low resistance portion, which similarly causes a short circuit state. It was

Furthermore, in processing with a laser beam, it is necessary to accurately control the irradiation position and to accurately control the on / off of the laser device that emits the laser beam.
Processing for this has been very complicated.

The present invention has been made in view of such circumstances, and its purpose is to prevent the occurrence of a short-circuit state in each photovoltaic element, and to reduce the number of man-hours and reduce the manufacturing cost. A method of manufacturing a device is provided.

[Means for solving problems]

According to the method of the present invention, the surface of the insulating substrate has an extended portion extending toward the peripheral edge of the substrate, and the first electrode layers are arranged adjacent to each other with a required space between them, By disposing a mask having an opening for exposing the surface of the first electrode layer excluding the extended portion and the surface of the gap portion of the first electrode layer on the side of the first electrode layer, the exposed portion A semiconductor layer including a photoactive layer formed on the first electrode layer, and extending from a position corresponding to each of the first electrode layers to the peripheral side of the substrate,
A second electrode layer having an extended portion that overlaps an extended portion of another adjacent first electrode layer with an area where the surface of the insulating substrate is exposed being interposed on the extension of the gap between the first electrodes. The layers are formed in order, and the second electrode layer, or the semiconductor layer and the second electrode layer are irradiated with an energy beam along a portion corresponding to a gap between the first electrode layers to divide them, and at the same time, When dividing, use the above mask,
By disposing at the same position as when forming the semiconductor layer, the division by the irradiation of the energy beam is limited to the second electrode layer in the opening, or the second electrode layer and the semiconductor layer in the opening. is there.

[Action]

In the method of the present invention, a short-circuit state is less likely to occur even if division processing is performed with an energy beam, and each division line can be made thin and inconspicuous.

Furthermore, in the method of the present invention, when the second electrode layer or the semiconductor layer is divided by irradiation with an energy beam,
By using the mask, the irradiation is limited to the part exposed by the opening, that is, the part where the semiconductor layer can be formed. This can be easily prevented, and in addition, it is possible to reduce complicated on / off of the laser.

〔Example〕

The case where the method of the present invention is applied to the manufacture of a photovoltaic device for a wristwatch will be specifically described below with reference to the drawings. 1st, 2nd, 3rd,
FIG. 4 is a schematic plan view showing a manufacturing process according to the method of the present invention. In the figure, reference numeral 1 shows an insulating substrate formed by coating an insulating material made of a polymer compound on the surface of a stainless plate. First, metal electrode layers 2a, 2b, 2c, 2d, which are first electrode layers divided into four parts by using a metal mask as shown in FIG. 1, on the surface of such an insulating substrate 1 and a terminal portion 2e independent of them. Is formed to a thickness of 1000 to 5000Å by, for example, a vacuum vapor deposition method or a sputtering method. Metal electrode layers 2a, 2b,
Both 2c and 2d have a rectangular shape in the main body, and each 2
They are formed in parallel with each other and are formed in a state in which a constant space 1 is provided between the opposing sides adjacent to each other.

Each metal electrode layer 2a, 2 located on the central side of the insulating substrate 1
All corners of b, 2c, 2d are cut out in 1/4 arc shape,
In addition, each metal electrode layer 2 located on the peripheral side of the insulating substrate 1
Extension portions 2 extending from the other corners located on the same side in the circumferential direction of a, 2b, 2c, 2d toward the peripheral edge side of the insulating substrate 1 respectively.
p, 2q, 2r, 2s are formed. Each of the extended portions 2p, 2q, 2r is formed in an L shape in plan view, and each metal electrode layer 2
a, 2b, 2c extends from the corners located on the same side in the circumferential direction toward the peripheral edge of the insulating substrate 1, and extends along the outer circumference of other adjacent metal electrode layers 2b, 2c, 2d from the middle. It is formed so as to be refracted at a constant interval l from this.

The extended portion 2s is wider than the other extended portions 2p and the like and linearly extends from one corner of the metal electrode layer 2d toward the periphery of the insulative substrate 1. Layer 2a
A terminal portion 2e is formed on the outer side of this with a gap 1 therebetween.

When the formation of the metal electrode layers 2a, 2b and the terminal portion 2e is completed, the surface of the metal electrode layer excluding the extended portions 2p, 2q, 2r, 2s and the opening of the gap portion of the metal electrode layer are exposed. By disposing a metal mask having a portion so as to cover the metal electrode layer, a semiconductor layer 3 having a photoactive layer such as an amorphous semiconductor is formed to a thickness of 4000 to 6000Å as shown in FIG. Except for the formation or extension of the semiconductor layer 3 or the upper half of the extended portions 2p to 2s, the four metal electrode layers 2a to 2d and the entire gap formed therebetween, and the metal electrode layer 2a.
~ 2d is formed in a rectangular shape slightly protruding outward from the outer peripheral edge of the metal electrode layers 2a to 2c, and other adjacent metal of the extended portions 2p, 2q, 2r of the metal electrode layers 2a to 2c. Electrode layers 2b, 2c, 2d
A gap m for exposing the insulating substrate 1 is left between the portion and the portion that is bent and formed along the outer periphery of the insulating substrate 1.

Then, a transparent electrode layer 4 as a second electrode layer is formed on the surface of the semiconductor layer 3 by using a metal mask as shown in FIG.
Form to a thickness of 0Å.

On the surface of the transparent electrode layer 4 or the surface of the semiconductor layer 3, the metal electrode layers 2a, 2b, 2c, 2d except for the extension portions 2p, 2q, 2r, 2s and the terminal portion 2e and between them. Formed in a rectangular shape over the entire surface of the gap formed in, and a portion corresponding to each metal electrode layer 2a, 2b, 2c, 2d, the extended portion 2p,
2q, 2r, 2s is formed in a linear extended portion 4p toward the peripheral edge of the insulating substrate 1 from positions corresponding to other corners located on the opposite side with a distance 1 between them. 4q, 4r, 4s extend, the tip portion of the extended portion 2 of the metal electrodes 2a, 2b, 2c
It is superposed on p, 2q, 2r and the terminal portion 2e.

As a result, the portions surrounded by the extended portions 2p, 2q, 2r and the extended portions 4q, 4r, 4s and the semiconductor layer 3 which overlap with each other are located on the extension of the gap l between the metal electrode layers 2a to 2d, respectively. Regions 1a, 1b, 1c where the surface of the insulating substrate 1 is exposed are formed, and a region 1d where the surface of the insulating substrate 1 is exposed is formed on the extension of the gap between the extension portion 2s and the extension portion 4p. It is in the state of being

Next, as shown in FIG. 4, a laser beam is used to cover the exposed regions 1a to 1c of the insulating substrate 1 and 1b to 1d along the widthwise center of the space 1 between the metal electrode layers 2a to 2d. Scribing into a cross shape. For this processing, the metal mask used when forming the semiconductor layer 3 in advance is set at the same position as that set when forming the semiconductor layer 3. As a result, the laser beam can scribe only the regions of the transparent electrode layer and the semiconductor layer exposed in the opening of the metal mask. That is, it is possible to suppress the irradiation of the portion where the semiconductor layer is not formed, in which the irradiation with the laser beam is undesired. Further, the laser beam does not have to be troublesome to determine the scribing position by controlling the on / off of the laser device, and can be moved on the metal mask in the on state and moved to the scribing position for continuous and sequential operation.

The scribing depth is at least 4 for the transparent electrode layer 4.
The depth may be such that it can be divided, but the transparent electrode layer 4 and the semiconductor layer 3 may be processed so as to be divided.

As the laser beam, a YAG laser device with a Q switch (wavelength: 1.06 μm or 0.53 μm) is used, and the output is 0.05 to 0.2.
W, scanning speed is set to about 20 mm / sec to 100 mm / sec.

Thereby, the metal electrode layers 2a, 2b, 2c, 2d and the transparent electrode layers 4a, 4
4 of the mode in which the semiconductor layers 3a, 3b, 3c, 3d are sandwiched between b, 4c, 4d
The photovoltaic elements are connected in series, and a photovoltaic device having the extension portions 2s and 4p as terminals is configured.

A processing residue is formed on the laser-scribed dividing surface, and a microcrystallized or crystallized portion is generated in the semiconductor layer 3. A metal mask is used between the metal electrode layers 2a, 2b, 2c, 2d. The gap is set to about 0.3 mm, while the gap of the part divided by laser scribing is 20 mm.
It is about 100 μm, the divided surface does not come into contact with the metal electrode layers 2a to 2d, and a short circuit does not occur.

When the semiconductor layer 3 shown in FIG. 2 is formed, the peripheral edge of the semiconductor layer 3 protrudes from the outer peripheral edges of the metal electrode layers 2a to 2d and its extended portions 2p, 2q,
It is also conceivable to form it so as to cover the portion of 2r, 2s that is bent in the circumferential direction. In this case, if the transparent electrode layer 4 is formed as shown in FIG. 6 and the transparent electrode layer 4 and the semiconductor layer 3 by laser scribing are divided, structurally, as in the case shown in FIG. It is possible to configure a photovoltaic device in which photovoltaic elements are connected in series. However, in this case, the divided surface of the semiconductor layer 3 by the laser scribing process comes into direct contact with the extended portions 2p, 2q, 2r of the metal electrode layers 2a, 2b, 2c. 2
Transparent electrode layers 4a, 2b, 2c through the extension 2p, 2q, 2r
The 4b, 4c and the metal electrode layers 2a, 2b, 2c may be in a short circuit state, which is a functionally undesirable state.

〔effect〕

As described above, in the method of the present invention, the extended portion of the first electrode layer and the extended portion of the second electrode layer are provided with an area where the surface of the insulating substrate is exposed on the extension of the gap between the first electrode layers. Since the first electrode and the second electrode are formed so as to be overlapped with each other, when the second electrode layer or the semiconductor layer is separated from the second electrode layer along the gap between the first electrode layers, the divided section of the semiconductor layer is any extension. There is no contact with the portion, electrical loss due to microcrystallization of the semiconductor layer is small, and a short-circuit state due to microcrystallization of the semiconductor layer can be suppressed. Further, when the division is performed using the energy beam, the metal mask used for forming the semiconductor layer can be used, the operation of the energy beam is facilitated, and the manufacturing efficiency can be improved. It plays.

[Brief description of drawings]

1, 2, 3, 4 are schematic diagrams showing the manufacturing process by the method of the present invention, FIGS. 5, 6 are schematic diagrams showing an example in the case where the process of the present invention is not desirable, and FIG. 7 is a conventional method. Fig. 8 is a schematic plan view of the photovoltaic device manufactured in Fig. 8, Fig. 8 is a cross-sectional view taken along the line VIII-VIII in Fig. 7, and Figs. 9 and 10 are schematic views showing a scribing process using a laser beam of a conventional method. . 1 ... Insulating substrate, 2a, 2b, 2c, 2d ... Metal electrode layer, 2e ... Terminal part, 2p, 2q, 3r, 2s ... Extension part, 3 ... Semiconductor layer, 3a, 3b, 3c,
3d ... divided semiconductor layer, 4 ... transparent electrode layer, 4a, 4b, 4c, 4d ... divided transparent electrode layer, 4p, 4q, 4r, 4s ... extended portion

Claims (1)

[Claims] 1. An insulative substrate having a first electrode layer having an extended portion extending to the peripheral side of the substrate on the surface thereof, the first electrode layer being adjacently disposed so as to be spaced apart from each other by a required distance, and the extended portion. Except that the mask having an opening for exposing the surface of the first electrode layer and the surface of the gap of the first electrode layer is formed on the exposed portion due to the arrangement on the first electrode layer side. The semiconductor layer including the exposed photoactive layer and the first electrode layer, and the first electrode layer and the first electrode layer are extended to the peripheral side of the substrate, and the surface of the insulating substrate is exposed on the extension of the gap between the first electrodes. A second electrode layer having an extended portion that overlaps an extended portion of another first electrode layer adjacent to each other with a region interposed therebetween is formed in this order, and the second electrode layer or the second electrode layer and the semiconductor layer The energy beam along the portion corresponding to the gap between the first electrode layers. By, as well as disrupt them,
In dividing the mask, the mask is arranged at the same position as in the formation of the semiconductor layer, so that the dividing by the irradiation of the energy beam causes the second electrode layer in the opening to be separated,
Alternatively, it is limited to this and the semiconductor layer, and a method for manufacturing a photovoltaic device.