JP2001085711A - Thin film solar battery module and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfy both appearance and reliability by discretely arranging photovoltaic thin film semiconductor layer in the longitudinal direction in a center part on the width side of a bus area and filling the hole with adhesive conductor. SOLUTION: SiO2 is formed on a transparent insulating substrate 1 and a transparent electrode layer 16 is formed on it. Grooves 18 are installed in the transparent electrode layer 16 by a laser work method. Strip individual region 17 are formed and a semiconductor layer 19 is formed on them. A rear electrode layer 22 is formed on the semiconductor layer 19 and the rear electrode layer 22 is made into individual electrodes 23 by grooves 24. Unit elements 28 across a semiconductor are connected in series between the transparent electrode and the rear electrode. Bus areas 3 and 3' are installed on both ends to which the elements 28 are connected. The plural discrete holes 29 are installed in the regions 3 and 3' and the holes 29 are filled with adhesive conductors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method for manufacturing the semiconductor device, and more particularly, to a solar cell module, and more particularly, a device for performing photoelectric conversion using a thin film semiconductor layer such as amorphous silicon. The present invention relates to a battery module and a method for manufacturing the battery module. More specifically, the present invention relates to a structure of a positive / negative electrode take-out stage of the above-mentioned solar cell module and a method of attaching an electrically good conductor.

[0002]

2. Description of the Related Art Photovoltaic power generation has become popular as a means for solving environmental problems such as depletion of resources or an increase in the amount of generated carbon dioxide, and the use of semiconductor materials such as silicon is small. Attention has been focused on thin-film solar cells.

A thin-film solar cell has an efficiency of converting light into electric power that is several percent lower than a solar cell using a crystal substrate that has been conventionally put into practical use, but the appearance of a light incident surface, which is an appearance after installation, is low. Compared to crystal-based solar cells, 1) the color is brown or black, similar to roofs of houses or buildings. 2) Strips densely arranged without any visible wiring or internal mechanism. Since the solar cell element is present on the entire surface, it looks uniform from a distance, and has attracted much attention in terms of design. In particular, a thin-film solar cell module in which a solar cell element is formed directly on a transparent insulating substrate and connected on the substrate (hereinafter, referred to as a substrate-integrated solar cell module) has been proposed. Up to about 90% can be realized, and portions other than the elements are hardly noticeable.

[0004] The structure of a solar cell portion of a substrate-integrated solar cell and a method of manufacturing the same are disclosed in US Pat.
No. 2092. A transparent conductive film is formed on a transparent insulating substrate such as glass, separated into individual strip-like photovoltaic regions by laser processing lines, and a p-type, i-type
And n-type amorphous silicon are formed on the entire surface to form a photovoltaic semiconductor layer. A connection groove for connecting to the next element is formed by laser processing at a position shifted parallel to the first processing line, and after forming the back electrode layer, it is parallel to the connection groove and opposite to the separation groove of the transparent electrode Then, a back electrode separation groove is formed. Through these steps, a thin-film solar cell in which a plurality of strip-shaped photovoltaic elements are connected in series to one substrate is formed.

In this configuration, the connection portion of the solar cell has a width of 0.1 mm.
It exists as a thin line of 3 mm to 0.5 mm and cannot be visually recognized from a place as far as 20 m.

A bus means is provided at or near the end of the connection in order to extract the electric power of the thin-film solar cell. Since the bus means does not contribute to power generation, a good conductor is provided in a strip-shaped area (bus area) slightly narrower than the photovoltaic element so that power can be more easily collected. As a good conductor, for example, a method in which a paste in which metal particles such as glass frit are dispersed is applied to the region in a process immediately after forming a transparent electrode on a transparent insulating substrate as disclosed in JP-A-3-171675, or As disclosed in Japanese Patent Application Laid-Open No. 9-83001, there is a method in which a back electrode layer and a semiconductor layer in a bus region are linearly removed, and a solder-plated copper foil is connected to a portion where a transparent electrode is exposed by using ceramic solder.

The former method is specifically shown in FIG.
Bus regions 3 and 3 'for collecting positive and negative power are provided on the thin-film solar cell 100, and a back electrode layer and a semiconductor layer are linearly removed at a substantially central portion in a width direction of the bus regions 3 and 3' to expose a transparent electrode. Provided on those are discretely provided bumps of ceramic solder containing lead, tin, zinc and antimony as essential components using an ultrasonic soldering iron, and solder plated copper foils 4, 4 'are provided thereon. I have.

[0008]

The prior art described above is
Metals are used to solve problems such as corrosion caused by the reaction between the paste material or solder material and the back electrode material, and peeling of the connection part, etc., which occur with the older technology of installing a good conductor with solder or conductive paste on the back electrode. It is invented from the viewpoint of eliminating the problem of electrolytic corrosion during intercalation and the problem of peeling by directly applying a paste material or a solder material to the transparent electrode layer. It was found that the portion where the paste such as glass frit was in contact with the transparent electrode became a silvery glossy portion when viewed from the light incident side.

On the other hand, in the structure disclosed in Japanese Patent Application Laid-Open No. 9-83001, the back surface electrode layer and the semiconductor layer are linearly removed at a substantially central portion in the width direction of the bus region, and the metallic luster of the solder-plated copper foil passes through a portion where the transparent electrode is exposed. Was seen from the light incident surface.

It has been found that these external characteristics significantly impair the design of a solar cell module of the type installed as part of a building.

That is, in the case where the solar cell module is used as a building material such as a roof of a general house or a component similar to the building material, many architects demand a design similar to or exceeding the conventional building material. I have. For example, in the case of using a solar cell as a roofing material, appearance characteristics such as a brown color tone, matteness, and a uniform whole surface without a pattern are required as in a normal colonial roof tile or a single.

In this case, the metallic luster shown above is extremely different from the color tone of the solar cell roof material, and is notable because it becomes a noticeable pattern.

However, it is obvious that reliability is significantly reduced by the method of attaching to the back electrode as in the prior art, and it is necessary to propose a structure that satisfies both appearance and reliability. This is a very important issue.

[0014]

The inventor of the present invention has improved the means for solving the above problems day and night with the structure disclosed in Japanese Patent Application Laid-Open No. 9-83001 as a starting point. Has found a simple and clear means to disclose.

The gist of the present invention is that a layer including a transparent electrode layer, a photovoltaic thin film semiconductor layer, and a back electrode layer is sequentially formed on a transparent insulating substrate, and is divided into a plurality of regions. A bus area of a thin-film solar cell module having a bus area to which photovoltaic elements are electrically connected and from which power is taken out as an end of the connection and a good conductor made of a metal wire or a metal ribbon for collecting power in the bus area. The hole is formed by removing the photovoltaic thin-film semiconductor layer and / or the back electrode layer so as to expose the transparent electrode layer, which is discretely arranged in the longitudinal direction at the center on the width side of the bus region. And an adhesive conductor that fills the opening and mechanically and electrically connects the bus region and the good conductor.

The adhesive conductor used here may be one obtained by placing a conductive liquid containing a conductive metal or an organic metal component such as a conductive paste or the like in the above-mentioned opening and solidifying the conductive liquid. Solder containing lead, tin, zinc and antimony as essential components, more specifically, 1 to 60% by weight of lead, 10 to 98% by weight of tin, 0.01 to 25% by weight of zinc and 0.01 to 25% by weight of antimony. Those having 50% by weight are preferably used.

A good conductor made of a metal wire or a metal ribbon is a copper wire or foil coated with solder or tin, preferably a solder-plated copper foil having a width of 2 mm or more, and a solder plating thickness of 50 μm or more. Is 10
Those having a size of 0 μm or more and 200 μm or less are preferably used.

As a method of manufacturing these structures, the photovoltaic thin film semiconductor layer and / or the back electrode layer are arranged discretely in the longitudinal direction at the center on the width side of the bus region so that the transparent electrode layer is exposed. Providing an opened hole, providing a bump of an adhesive conductor in the opening, and connecting a good conductor made of a metal wire or a metal ribbon for collecting power in a bus area to the bump of the adhesive conductor. This part is implemented in the process. The composition of the bump is to dispense a conductive liquid containing a conductive metal or an organic metal component such as a conductive paste and harden it by post-heating, or to use solder or lead, tin, zinc and antimony used for ceramics as an essential component. The solder to be soldered may be attached by heating with a soldering iron that oscillates ultrasonic waves and oscillates ultrasonic waves.

In order to form an opening, a metal tool having a tip portion smaller than the size of the opening is mechanically pierced, or an ultrasonic wave is applied using a metal tool such as an ultrasonic soldering iron. This can be done in a mechanical step of mechanically drilling the holes or in a thermal step using the radiant energy of the laser.

Further, although it is applicable only when the above-mentioned solder is used, by optimizing the frequency and power of the ultrasonic wave of the ultrasonic soldering iron, and the distance between the iron tip and the processed part,
By simultaneously performing the step of providing the opening and the step of providing a solder bump in the opening, a step characteristic of the present invention can be realized in one step. In this case, the device is devised based on the conditions set in the device for soldering the ceramic. Set the ultrasonic oscillation power to at least 10% higher, and make sure that the power always comes out by using an oscillator in the iron part of the ultrasonic soldering iron (only the speaker coil and ball piece attached to the iron tip) ) Is provided with a cooling means for lowering the temperature.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a specific embodiment will be described with reference to FIG.
This will be described with reference to FIG. The contents described here are for explaining the form, and the present invention is not limited to the form. The present invention can be applied to another form as long as the technical idea is reflected.

[Thin Film Solar Cell] The cross section of FIG. 1 shows a thin film solar cell used in the present invention.

Transparent insulating substrate 1 used in thin-film solar cell
Glass or heat-resistant plastic is used.
For example, SiO ₂ is formed on this substrate so that impurities of the substrate do not diffuse into the layer thereabove. A transparent electrode layer is formed on this.

[0024] As the transparent electrode layer 16, SnO ₂ is preferably used grown form unevenness is formed by the apex angle of the crystal grains. As a forming method, a thermal CVD method is generally used.

The transparent electrode layer is provided with a groove 18 by using a laser processing method or the like, and a strip-shaped individual region 17 is formed.

A semiconductor layer 19 is formed thereon. As the semiconductor layer, a photovoltaic junction of amorphous silicon, thin-film polycrystalline silicon, CIS, CdTe, or the like is appropriately formed. Also, the material of the transparent electrode is appropriately selected from those suitable for these semiconductors.

These semiconductor layers are provided with a groove 21 for connection with an adjacent photovoltaic element.

On the semiconductor layer 19, a back electrode layer 22 is formed. As the back electrode layer, an electrode in which a transparent conductive material such as ZnO and a high light reflective metal such as Ag are combined is preferably used.

These back electrode layers 22 become individual electrodes 23 by the grooves 24. With this configuration, the unit elements 28 each having a semiconductor sandwiched between the transparent electrode and the back electrode are connected in series.

At both ends where these elements 28 are connected, bus areas 3 and 3 'for collecting power are provided. In this region, a plurality of discrete openings 29 for exposing the transparent electrode layer are provided.

In the experiment of the inventor, in the experiment of the inventor, the semiconductor layer and the back surface are efficiently rubbed by rubbing with a higher ultrasonic power than when soldering with an ultrasonic soldering iron tip described in a later step. It was found that the electrode layer could be removed to expose the transparent electrode layer. By utilizing this principle, it is possible to manufacture an industrially viable device. In this case, it has been found that the oscillator always oscillates and generates heat, and the resonance point of the oscillator changes with this heat generation, so that the ultrasonic power decreases. As a countermeasure, it has been found that stable ultrasonic power can always be ensured by blowing or cooling the oscillator. Further, by this improvement, it was possible to similarly cut and attach the solder even when the ceramic solder was melted and attached to the iron tip of the ultrasonic soldering iron. in this case,
In the shaving process and soldering process, the power, the distance between the iron tip and the bus area, and in the shaving stage, use a large power to hold down the iron tip, and when soldering, lower the power a little and feel the iron tip floating It was found that the two steps could be performed efficiently.

On the other hand, as another method, it is possible in principle to discretely remove the back electrode and the semiconductor by setting the condition of the laser to a condition for partially removing the back electrode. However, it is necessary to wait for the emergence of a device that performs this method at high speed.

In the openings, bumps 26 of ceramic solder are discretely formed. The diameter of these bumps or apertures is 2 mm as disclosed in Japanese Patent Application Laid-Open No. Hei 9-135035 of the applicant, and the distance between the centers of the bumps is about 20 mm.

The ceramic solder contains a rare earth element so that it can be bonded to a transparent electrode or ceramic.
It is commercially available from Senju Metal under the trade name of Cerasolza. These components contain 1 to 60% by weight of lead and 10% by weight of tin.
Those containing up to 98% by weight, 0.01 to 25% by weight of zinc and 0.01 to 50% by weight of antimony are preferably used.

In another embodiment, instead of ceramic solder, a metal or conductive resin-based conductive paste is provided in the opening using a dispenser or screen printing. Thereafter, the bumps are formed by drying with hot air.

As the conductive paste, a commercially available paste is preferably used. However, in practicing the present invention, the color tone after drying needs to be dark. As the paste material, a carbon-based, copper-based, or nickel-based paste is preferably used.

The solder plated copper foil 4 is connected to the bump 26. The solder-plated copper foil 4 is formed by coating a copper foil having a thickness of about 0.2 mm and a width of several mm with ordinary eutectic solder. The corrosion resistance is improved by this coating, and there is an effect that solder connection can be easily performed only by arranging the copper foil on the bump and pressing the copper foil with a soldering iron.
In addition, in order to secure the bonding strength between the bump and the solder, the soldering strength must be at least 1 kg, but in order to secure this strength, the solder thickness on the solder-plated copper foil must be 50 μm or more. Preferably, it is 0.1 mm.

The reason that the solder strength is reduced when the amount of the solder is small is that the copper foil surface has irregularities of 0.1 mm or more with respect to the contact surface, and if there is not enough solder to fill the irregularities, the solder joint will be a surface. This is because it is not a shape but a dot shape.

The soldering process used here is a process that does not use flux. This is because when a flux is used, the acid in the flux remains to significantly reduce the reliability.

The subsequent steps are not described in detail in the specification of the present invention, but as shown in FIGS.
(A) A step of connecting another solder-plated copper foil 5, 5 'to the 3.3' solder-plated copper foil 4, 4 'on the bus area.

As shown in FIG. 3B, a step of setting the fillers 6 and 8 for burying the insulating sheet at predetermined positions with the insulating sheet 7 sandwiched therebetween.

The solder-plated copper foils 5, 5 'up to the power extraction connection means are bent at the terminal box installation position so that the terminal box side end thereof is perpendicular to the substrate, and FIG. As shown, a step of covering with a filler material 9 covering the entire surface of the substrate in which a slit 10 for passing a solder-plated copper foil is opened.

Specifically, as shown in FIGS. 3 (D) and 4 (E), a small Tedler sheet piece 13 slightly larger than the hole of the protective cover is cut on the sheet of the filling material with a solder-plated copper foil. Step of setting around and further setting EVA sheet small pieces 12 of almost the same size and step of covering the protective cover Remove solder-plated copper foil from the opening of the protective cover and place it in a position where the copper foil and the protective cover do not come in contact with heat resistant tape Temporarily fixing step, see FIGS. 4 (F) and 4 (G).

In addition, a sealed solar cell module is produced through a step of heating and pressing with a double vacuum tank type laminator (abbreviation: vacuum laminator).

The steps shown in FIGS. 3 and 4 show the relationship with the elements formed in the steps after the structure of the present invention is formed. Of course, it is not limited to this configuration. Any element that includes the elements of the present invention can be used as appropriate.

[0046]

Next, an embodiment of the present invention will be described using an amorphous silicon solar cell formed on glass.

(Example 1) As the transparent insulating substrate 1, short sides 5
A blue plate glass having a length of 0 cm and a length of 100 cm and a thickness of 4 mm was used. This glass has a chamfered periphery of the cut surface to prevent thermal cracking and mechanical destruction during the process.

On this glass, SiO 2 was formed as an alkali barrier at a thickness of 1000 ° by thermal CVD to form a transparent conductive layer 16.
Was formed by fluorine-doped SnO ₂ at 10000 °. The surface has irregularities formed by the apex angles of the crystal grains.

The grooves 18 were formed in the transparent electrode layer 16 by laser processing using the second harmonic of a YAG laser.

A semiconductor layer 19 of p-type amorphous silicon carbide, 3,000-degree i-type amorphous silicon, and 300-degree n-type amorphous silicon was formed thereon by plasma CVD.

Using the second harmonic of the YAG laser, a groove 21 for connection to an adjacent photovoltaic element was provided.

Further, on the semiconductor layer 19, ZnO was formed at a thickness of 1000 ° and Ag was formed at a thickness of 3000 ° by a sputtering method, thereby forming a back electrode layer 22.

The grooves 24 were formed on the back electrode layer 22 using the second harmonic of the YAG laser to obtain individual electrodes 23. With this configuration, the unit elements 28 each having a semiconductor sandwiched between the transparent electrode and the back electrode are connected in series. The width of this unit element is about 10 mm.

Similarly, bus regions 3 and 3 'for collecting power were provided at both ends of these elements with a width of 5 mm using laser processing. The distance between the positive electrode bus region 3 ′ and the negative electrode bus region 3 was 48 cm. Semiconductors and amorphous silicon were mechanically removed by using an ultrasonic soldering iron every 2 cm at the center in the width direction of the bus region to form an opening 27 on one side 4.
96 bumpers were formed in 8 pieces, and bumps 26 of Cerasolzer were provided.
The size of this hole is 2 mm in diameter.

The bump has a width of 2 mm and a thickness of copper foil of 0.2 m.
m, a solder-plated copper foil 4 having a solder thickness of 0.1 mm was connected.

The peripheral region 27 of the substrate 1 was polished by a sand blast method to provide a region in which all layers were not present.

The solder-plated copper foil 4 on the bus area
4 ′ was adjusted so as to form a gap of 0.1 mm so that the filler filled the gap between the copper foil and the element surface.

Solder-plated copper foils 4 on bus areas 3 and 3 '
4cm length 30cm width 5mm 5cm from the edge of the substrate
Are connected. The thickness of the copper foil and the thickness of the solder are the same as those of the above-mentioned solder-plated copper foil.

When the external appearance of the solar cell module was observed from the light incident side, the color tone of the entire surface was wine red. The connection portion of the solar cell was seen as a silver line of about 0.1 mm when viewed close. Also, when observing the bath area, the bumps appeared dark gray, but when observed about 2 m away, these points disappeared.

It has been found that the color of the solder becomes darker in color tone in the case of using the textured transparent electrode and in the case of using the plane transparent electrode.

(Examples 2 and 3) The connection portion of the present invention can be similarly formed by using a conductive paste instead of solder. When the copper paste was used, the color tone viewed from the light irradiation surface was dark red, and the color tone was similar to that of amorphous silicon. It was also found that the use of a chromium-based paste turned black. From a distance of 2 m or more, it was found that both were similarly inconspicuous.

[0062]

As described above, according to the present invention, the method of connecting a good conductor to the bus area is performed by discrete bumps, and the bases are discretely provided, so that the appearance of the portion can be greatly improved. It is possible to improve.

As a result, the inherent appearance characteristics of the substrate-integrated thin-film solar cell can be exhibited, and the superiority of the thin-film solar cell in building material applications can be fully exhibited. became.

[Brief description of the drawings]

FIG. 1 is a laminated perspective view of each member of a thin-film solar cell module of the present invention.

FIG. 2 is a laminated perspective view of each member of a conventional thin-film solar cell module.

FIG. 3 is a process diagram (1) of a wiring according to the present invention;

FIG. 4 is a process diagram (2) of the wiring of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transparent insulating substrate 2 Solar cell power generation area 3, 3 'bus area 4, 4' Means for increasing the conductance of the bus area (solder plated copper foil) 5, 5 'Connection means for outputting power to the outside and the bus area 6 (filler for embedding insulating sheet) 7 Insulating sheet 8 Filler for embedding wiring between insulating sheet and 5 9 Filling material 10 Opening provided in filling material for passing 5 wiring 11 Another insulating sheet with an opening for preventing the opening of the back protective cover from contacting with the wiring of 5 12 Filler for embedding the insulating sheet of 11 13 Back protective cover 14 Back protecting to pass the wiring of 5 Opening provided in cover 15 Insulating material used in conventional invention 16 Transparent electrode layer 17 Individual transparent electrode 18 Groove for individualizing transparent electrode 19 Semiconductor layer 20 Individually divided semiconductor layer 2 1 groove provided in the semiconductor layer for connecting adjacent photovoltaic elements 22 back electrode layer 23 individual back electrode 24 groove for separating back electrode 25 groove for connecting conductance increasing means to bus area Reference Signs List 26 solder bump 27 insulating region provided around thin-film solar cell 28 individual photovoltaic element constituting thin-film solar cell 29 discrete opening for exposing transparent electrode layer 100 solar cell element

Claims (13)

[Claims] 1. A layer including a transparent electrode layer, a photovoltaic thin film semiconductor layer, and a back electrode layer is sequentially formed on a transparent insulating substrate,
A photoconductor element, which is divided into a plurality of areas, is electrically connected, and a bus area from which power is taken out as an end of the connection, and a good conductor made of a metal wire or a metal ribbon for collecting power in the bus area. A thin film solar cell module comprising: a photovoltaic thin film in which a connection between a bus region and the good conductor is discretely arranged in a longitudinal direction at a center portion on a width side of the bus region to expose a transparent electrode layer. A thin-film solar cell module comprising: an opening from which a semiconductor layer and / or a back electrode layer is removed; and an adhesive conductor that fills the opening and mechanically and electrically connects a bus region and a good conductor. . 2. The thin-film solar cell according to claim 1, wherein the adhesive conductor is formed by setting and solidifying a conductive liquid containing a conductive metal or an organic metal component in the opening. module. 3. The thin-film solar cell module according to claim 1, wherein the adhesive conductor is a ceramic solder or a solder containing lead, tin, zinc and antimony as essential components. 4. The thin-film solar cell module according to claim 1, wherein said good conductor is a copper wire or foil coated with solder or tin. 5. The solder containing lead, tin, zinc and antimony as essential components contains 1 to 60% by weight of lead and 10 to 9% of tin.
The thin-film solar cell module according to claim 3, wherein 8% by weight, 0.01 to 25% by weight of zinc, and 0.01 to 50% by weight of antimony. 6. The thin-film solar cell according to claim 1, wherein the good conductor is a solder-plated copper foil having a width of 2 mm or more, and a thickness of the solder plating is 50 μm or more, preferably 100 μm or more and 200 μm or less. module. 7. A layer including a transparent electrode layer, a photovoltaic thin film semiconductor layer, and a back electrode layer is sequentially formed on a transparent insulating substrate,
Forming a thin-film solar cell having a bus region in which photovoltaic elements divided into a plurality of regions are electrically connected and collecting power as an end of the connection; and a central portion on the width side of the bus region. Forming an opening from which the photovoltaic thin-film semiconductor layer and / or the back electrode layer are removed so as to expose the transparent electrode layer which is discretely disposed in the longitudinal direction, and a bump of an adhesive conductor is provided in the opening. And a step of connecting a good conductor made of a metal wire or a metal ribbon for collecting power in a bus area to the bumps of the adhesive conductor. 8. The method for manufacturing a thin-film solar cell module according to claim 7, wherein the step of placing the bump of the adhesive conductor in the opening includes a step of dispensing a conductive liquid containing a conductive metal or an organometallic component. Method. 9. A step of installing a bump of an adhesive conductor in the opening, wherein at least a part of the solder containing lead, tin, zinc and antimony as an essential component is irradiated with a soldering iron that oscillates ultrasonic waves. The method for manufacturing a thin-film solar cell module according to claim 7, comprising a step of oscillating, heating, and attaching. 10. The method according to claim 1, wherein the step of providing the opening is a step of mechanically drilling with a metal tool having a tip portion smaller than the size of the opening. 11. The method according to claim 7, wherein the step of forming the opening is a step of mechanically piercing with a metal tool having a tip portion smaller than the size of the opening by using ultrasonic waves.
3. The method for manufacturing a thin-film solar cell module according to item 1. 12. The method for manufacturing a thin-film solar cell module according to claim 7, wherein the step of providing the holes is a step of thermally piercing using radiant energy of a laser. 13. The thin-film solar cell according to claim 7, wherein the step of providing the opening using a soldering iron that oscillates an ultrasonic wave and the step of installing a solder bump in the opening are performed simultaneously. Manufacturing method of battery module.