TWI620337B - Method for manufacturing solar cell module - Google Patents

Abstract

The invention provides a method for manufacturing a solar cell module. In one embodiment of the method for manufacturing a solar cell module, in the solar cell 2 having no bus bar electrode, the connection line 3 is directly connected to the finger electrode 12 via the adhesive film 15. In this method, when the pressure from the pressing member 21 is applied to the connecting wire 3, the adhesive film 15 is pressed to the uneven surface constituted by the finger electrodes 12, and the finger electrodes 12 are arranged on the light receiving surface 2a. . Therefore, even if the pressing member 21 having a width wider than the line width of the connecting wire 3 is pressed at a low pressure of 1.0 MPa or less uniformly, the resin of the adhesive film 15 can be sufficiently ensured at the time of pressure bonding. It is possible to prevent the solar cell unit 2 from being broken and to achieve a good connection.

Description

Solar cell module manufacturing method

The invention relates to a method of manufacturing a solar cell module.

Since the solar cell module is a device that directly converts energy into electric energy, it is attracting attention as a clean energy source, and it is expected that the market will be rapidly expanded in the future. In such a solar cell module, a structure in which a plurality of solar cells are connected in series according to a required value of a voltage is generally employed.

More specifically, in the solar cell module, the surface electrode and the back surface electrode are electrically connected by a wiring member such as a tab line, wherein the surface electrode is formed on the light receiving surface side of the solar cell unit, The back electrode is formed on the back side of the adjacent solar cell. In the past, the connection between the electrodes and the connecting wires is made by soldering, and the connection reliability is excellent, such as the conductivity and the fixing strength, and the cost is low and the versatility is high (see, for example, Patent Document 1).

Prior art literature

Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2005-236235

In recent years, in consideration of the viewpoint of environmental protection, etc., a method of connecting electrodes and connecting wires of a solar cell unit using, for example, a film-like adhesive is being studied without using solder. In the connection method using the adhesive film, the connection at a low temperature can be achieved as compared with the connection by solder. Therefore, it is possible to suppress cracking/warpage of the solar cell due to high temperature at the time of connection and volume shrinkage of the solder.

On the other hand, in the connection method using the adhesive film in the related art, at the time of connection, the solar cell unit in which the connection line is connected via the adhesive film is performed at a pressure of about 2.0 MPa using a press head or the like. Hot crimping. In such a conventional method, there is a possibility that the solar cell unit is broken due to the shearing force at the time of pressure bonding. As a method of connecting the solar cell unit and the connecting wire at a low pressure, a method of improving the fluidity of the adhesive to improve the resin repellent property at the time of pressure bonding may be mentioned. However, in this method, the tackiness of the surface of the adhesive film may become too strong, and in the state in which the adhesive film is wound into a roll, blocking may occur (adhesive agent). Transfer to the back of the substrate).

The present invention has been made to solve the above problems, and an object thereof is to provide a method for manufacturing a solar cell module, which can prevent cracking of a solar cell unit and achieve good connection when connecting a solar cell unit and a connection line. .

In order to solve the above problem, in the method of manufacturing a solar cell module of the present invention, an adhesive film is used to connect a finger electrode and a connecting line, the finger shape The electrodes are arranged on the light receiving surface of the solar cell unit, and a bus bar electrode for connecting the finger electrodes is not provided on the light receiving surface of the solar cell unit, and the connecting line on the finger electrodes is not provided. In the arrangement region, the connection line is placed via the adhesive film, and a pressure member having a width wider than the line width of the connection line is used, and a pressure of 1.0 MPa or less is applied to the arrangement area of the connection line, and the connection line is heat-pressed. Pick up.

In the method of manufacturing a solar cell module, in a so-called solar cell without a bus bar electrode, a connection line is directly connected to a finger electrode via an adhesive film. In this method, when pressure from the pressing member is applied to the connecting wire, the adhesive film is pressed to the uneven surface formed by the finger electrodes, and the finger electrodes are arranged on the light receiving surface. Therefore, even if the pressing member having a width wider than the line width of the connecting wire is pressed at a low pressure of 1.0 MPa or less uniformly, the resin can be sufficiently removed during the pressure bonding, and the solar cell can be prevented. Broken, and a good connection can be achieved.

Further, in the method for manufacturing a solar cell module of the present invention, the finger electrode and the connection line are connected by using an adhesive film which is arranged on the light receiving surface of the solar cell, and is characterized in that it is in the solar cell unit. On the light-receiving surface, a bus bar electrode that connects between the finger electrodes is provided in a width narrower than the width of the adhesive film, and the connection line is disposed via the adhesive film in the arrangement region of the connection wires on the bus bar electrode. A pressure member having a width wider than the line width of the connecting wire is used, and a pressure of 1.0 MPa or less is applied to the arrangement area of the connecting wire, and the connecting wire is thermocompression bonded.

The solar cell module manufacturing method has a width ratio adhesive film In the solar cell of the bus bar electrode having a narrow width, the connection line is connected to the bus bar electrode via the adhesive film. In this method, when pressure from the pressing member is applied to the connecting wire, the adhesive film is locally pressed by the bus bar electrode, and the bus bar electrode has a width narrower than the adhesive film. Therefore, even if the pressing member having a width wider than the line width of the connecting wire is pressed at a low pressure of 1.0 MPa or less uniformly, the resin can be sufficiently removed during the pressure bonding, and the solar cell can be prevented. Broken, and a good connection can be achieved.

Further, in the method for manufacturing a solar cell module of the present invention, the finger electrode and the connection line are connected by using an adhesive film which is arranged on the light receiving surface of the solar cell, and is characterized in that it is in the solar cell unit. On the light-receiving surface, a bus bar electrode that connects the finger electrodes is provided on the end side of the light-receiving surface with a width narrower than the width of the adhesive film, and the connection is made to the finger electrodes on the center side of the light-receiving surface. In the arrangement area of the wire, the connection line is disposed via the adhesive film so that at least a part of the wire is superimposed on the bus bar electrode, and a pressure member having a width wider than the line width of the connection line is used, and the arrangement area of the connection line is given 1.0 MPa. The following pressures are used to thermocompress the connecting wires.

In the method of manufacturing a solar cell module, the connection line is directly connected to the finger electrode via the adhesive film. In this method, when pressure from the pressing member is applied to the connecting wire, the adhesive film is pressed to the uneven surface formed by the finger electrodes, and the finger electrodes are arranged on the light receiving surface. Therefore, even if the pressing member having a width wider than the line width of the connecting wire is pressed at a low pressure of 1.0 MPa or less uniformly, the resin can be sufficiently removed during the pressure bonding, and the solar cell can be prevented. Broken, and a good connection can be achieved. Further, in the method of manufacturing a solar cell module, a bus bar electrode that connects between the finger electrodes is provided on the end portion side of the light receiving surface with a width narrower than the width of the adhesive film. Thereby, the bus bar electrode can be utilized as an alignment mark when the connection line is disposed. Further, since the bus electrodes can be collected from the finger electrodes at the end portions of the light receiving surface, the current collection efficiency of the solar cell module can be prevented from being lowered.

Further, it is preferable to arrange the connecting wires so as to straddle all of the finger electrodes on the light receiving surface. In this way, current collection can be performed from all of the finger electrodes, so that the current collection efficiency of the solar cell module can be sufficiently ensured.

Further, it is preferable that the finger electrodes have a thickness of 10 μm to 30 μm and a width of 5 μm to 90 μm. When the thickness/width of the finger electrode satisfies this range, the uneven surface formed by the finger electrode can be sufficiently formed. Therefore, the repellent property of the resin at the time of crimping can be more fully ensured.

Further, it is preferable that the ratio of the thickness of the finger electrode to the thickness of the adhesive film is in the range of 1:5 to 6:5. In this range, the unevenness of the resin at the time of pressure bonding can be more sufficiently ensured by the uneven surface formed by the finger electrodes.

Further, it is preferable that the bus bar electrode has a width of 90 μm or less. As described above, by reducing the width of the bus bar electrode, the adhesive film is further partially pressed by the bus bar electrode, so that the resin rejection at the time of pressure bonding can be more sufficiently ensured.

Further, it is preferable that the bus bar electrode has a thickness of 10 μm to 30 μm and a width of 5 μm to 90 μm. At this time, since the adhesive film is further partially pressed by the bus bar electrode, the resin rejection at the time of pressure bonding can be more sufficiently ensured.

Further, it is preferable to apply a pressure of 0.5 MPa or less to the arrangement area of the connection line, and to perform thermocompression bonding on the connection line. By further reducing the pressure applied to the arrangement area of the connecting wires, it is possible to more reliably prevent the solar cell from being broken.

Further, it is preferable to use a conductive adhesive film or an insulating adhesive film as the adhesive film. Thereby, the connection of the connecting wires can be well achieved.

According to the method of manufacturing a solar cell module of the present invention, when the solar cell unit is connected to the connecting line, the solar cell unit can be prevented from being broken, and a good connection can be achieved.

1‧‧‧Solar battery module

2, 32, 42‧‧‧ solar battery unit

2a, 32a, 42a‧‧‧ light surface

2b‧‧‧back

3‧‧‧Connecting line

11‧‧‧Substrate

12‧‧‧ finger electrodes

13‧‧‧ Bus bar electrode

14‧‧‧Back electrode

15‧‧‧Adhesive film

21‧‧‧ Pressurized components

33, 43‧‧‧ bus bar electrodes

K‧‧‧Hot press

P‧‧‧Connection line configuration area

FIG. 1 is a perspective view showing a solar battery module manufactured by using the method for manufacturing a solar battery module according to the first embodiment of the present invention.

Fig. 2 is a plan view showing a solar battery cell constituting the solar battery module of Fig. 1 from the light receiving surface side.

Fig. 3 is a plan view showing the solar battery cell of Fig. 2 from the back side.

4 is a cross-sectional view showing a state in which a solar cell is connected to a connecting line.

FIG. 5 is a plan view of the solar battery cell to which the solar cell module manufacturing method according to the second embodiment of the present invention is applied, viewed from the light receiving surface side.

Fig. 6 is a cross-sectional view showing a state in which a solar cell unit is connected to a connecting line.

Fig. 7 is a plan view showing a solar battery cell of a modification from the light receiving surface side.

Hereinafter, preferred embodiments of the method for manufacturing a solar cell module of the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]

FIG. 1 is a perspective view showing a solar battery module manufactured by using the method for manufacturing a solar battery module according to the first embodiment of the present invention. As shown in FIG. 1, the solar battery module 1 is configured such that a plurality of solar battery cells 2 are electrically connected to each other by a connecting wire 3.

One surface side of the solar battery cell 2 is a light receiving surface 2a on which a surface electrode is formed, and the other surface side of the solar battery cell 2 is a back surface 2b on which a back surface electrode is formed. Between the adjacent solar battery cells 2 and 2, the surface electrode on the light-receiving surface 2a side and the back surface electrode on the back surface 2b side are connected by a connecting wire 3, thereby forming a string in which the solar battery cells 2 are connected in series (string) ).

The solar battery module 1 as a product includes, for example, a matrix in which a plurality of strings are arranged. In addition, the solar cell module 1 is completed by a surface cover of the protective light-receiving surface 2a side in a state in which the matrix is sandwiched by a sheet for sealing using a sealing sheet. The back sheet on the back surface 2b side is laminated together, and a metal frame such as aluminum is mounted around the back sheet.

As the adhesive for sealing, for example, a light-transmitting adhesive such as an ethylene vinyl acetate (EVA) resin is used. and Further, for the surface cover, for example, a material having a light transmissive property such as glass is used, and for the back sheet, for example, a laminate obtained by sandwiching a glass or an aluminum foil with a resin film is used.

Next, a method of manufacturing the solar cell module 1 will be described in more detail.

In the description, the structure of the solar battery unit 2 will first be described. 2 is a plan view showing a light receiving surface side of a solar battery cell, and FIG. 3 is a plan view showing a back side of the solar battery cell. As shown in FIGS. 2 and 3, the solar battery unit 2 has a substrate 11.

The substrate 11 is formed in a substantially square shape by, for example, at least one of single crystal, polycrystal, and amorphous of Si, and the four corners of the substrate 11 are chamfered into an arc shape. One surface of the substrate 11 corresponds to the light receiving surface 2a of the solar cell unit 2, and the other surface of the substrate 11 corresponds to the back surface 2b of the solar cell unit 2. Further, the light-receiving surface 2a side of the substrate 11 may be an n-type semiconductor or a p-type semiconductor.

On the light-receiving surface 2a side of the substrate 11, as shown in FIG. 2, a plurality of finger electrodes 12 are provided as surface electrodes. The finger electrodes 12 are formed on substantially the entire surface of the light-receiving surface 2a of the substrate 11 in a direction substantially perpendicular to the extending direction of the strings of the solar cell modules 1, and are spaced apart by a predetermined interval along the extending direction of the strings. arrangement.

The finger electrode 12 is formed, for example, by coating and heating a metal paste. The thickness of the finger electrodes 12 is, for example, 10 μm to 30 μm, and the width of the finger electrodes 12 is, for example, 5 μm to 90 μm. Further, the interval between the adjacent finger electrodes 12 and 12 is, for example, about 2 mm.

As a material for forming the finger electrodes 12, a glass paste containing silver, A silver paste, a gold paste, a carbon paste, a nickel paste, an aluminum paste, and indium tin oxide (ITO) formed by firing/deposition are dispersed in an adhesive resin. Among them, in view of heat resistance, electrical conductivity, stability, and cost, it is preferred to use a glass paste containing silver.

On the light-receiving surface 2a side, the arrangement regions P and P of the pair of connection lines 3 are set in a direction substantially perpendicular to the finger electrodes 12. In the present embodiment, the bus bar electrode as the surface electrode is not provided, and the connection line 3 is connected to the finger electrode 12 via the adhesive film 15 to be described later. In view of sufficiently ensuring the current collecting efficiency of the solar cell module 1, the arrangement region P is set to be linear in such a manner as to straddle all of the finger electrodes 12 on the light receiving surface 2a. Further, the interval between the arrangement regions P and P is, for example, about 60 mm.

On the back surface 2b side of the substrate 11, as shown in FIG. 3, a bus bar electrode 13 and a back surface electrode 14 are provided. The bus bar electrode 13 is provided in a pair of straight lines at positions corresponding to the arrangement regions P and P of the connection line 3 on the light-receiving surface 2a side. Similarly to the finger electrodes 12, the bus bar electrodes 13 are formed by, for example, applying and heating a metal paste. The width of the bus bar electrode 13 is, for example, about 2 mm.

The back electrode 14 is formed, for example, by calcining an aluminum paste. The back surface electrode 14 is formed over the entire area of the back surface 2b side of the substrate 11 except for the portion where the bus bar electrode 13 is formed. On the back surface 2b side, the arrangement areas P and P of the pair of connection lines 3 are set along the bus bar electrodes 13. The connection line 3 is connected to the bus bar electrode 13 and the back surface electrode 14 via the adhesive film 15. The arrangement region P is set to be linear, for example, over substantially the entire length of the bus bar electrode 13.

Next, an adhesive film 15 (see FIG. 4) for connection of the connection wires 3 will be described.

The conductive adhesive for the adhesive film 15 contains, for example, 25 parts by mass of a film-forming resin, 20 parts by mass of a thermosetting resin, 55 parts by mass of a curing agent for a thermosetting resin, and 10 parts by mass of a silicone particle, And 10 parts by mass of conductive particles.

As the film-forming resin, a thermoplastic polymer such as a phenoxyl resin, a polyester resin, or a polyamide resin is used from the viewpoint of achieving good film formation. Among these resins, a phenol oxygen resin is preferably used. Further, in consideration of the fluidity of the adhesive film 15, the weight average molecular weight of the thermoplastic polymer is preferably from 10,000 to 10,000,000.

Examples of the thermosetting resin include an epoxy resin, a polyimide resin, an unsaturated polyester resin, a polyurethane resin, a bismaleimide resin, and a triazine-double. Triazine-bismaleimide resin and phenol resin. Among these resins, an epoxy resin is preferably used in consideration of heat resistance.

The curing agent for a thermosetting resin refers to a material that promotes curing of the thermosetting resin when heated together with the thermosetting resin. As the curing agent, an imidazole curing agent, a hydrazide curing agent, an amine curing agent, a phenol curing agent, an acid anhydride curing agent, and a boron trifluoride-amine complex are used. Sulfur salts, iodized salts, salts of polyamines, amine imides, and dicyandiamide. When using epoxy When the resin is used as a thermosetting resin, it is preferred to use an imidazole curing agent, an oxime curing agent, a boron trifluoride amine complex, a sulfur salt, an amine sulfimine, a salt of a polyamine, and a dicyandiamide. .

As the fluorenone particles, an anthrone rubber particle, an anthrone resin particle, an anthrone composite particle or the like is used. The anthrone rubber particles are, for example, an anthrone rubber particle having a structure in which a linear dimethylpolysiloxane is crosslinked. The fluorenone resin particles are, for example, particles of a polyorganosilsesquioxane cured product having a structure in which a siloxane chain is crosslinked to a three-dimensional network represented by (RSiO3/2)n. structure.

As the conductive particles, for example, gold particles, silver particles, copper particles, nickel particles, gold-plated nickel particles, gold-plated/nickel plastic particles, copper-plated particles, and nickel-plated particles are used. The average particle diameter of the conductive particles is preferably from 1 μm to 20 μm, more preferably from 1 μm to 5 μm, from the viewpoint of ensuring conductivity.

Further, the conductive adhesive may contain a coupling agent for improving the adhesion to the adherend and the wettability. Examples of the coupling agent include a silane coupling agent and a titanate coupling agent.

Further, in the solar cell of the type of the busbar-free electrode such as the solar cell unit 2, it is also considered that since the connecting wire 3 is directly connected to the finger electrode 12, if it is at the finger electrode 12 The presence of conductive particles of 5 μm or more thereon hinders conduction between the connection line 3 and the finger electrodes 12. Therefore, instead of the conductive adhesive, the adhesive film 15 can be used, and the adhesive film 15 is used without a guide. An insulating adhesive for electric particles. In this case, the occurrence of the conduction failure between the connection line 3 and the finger electrode 12 as described above can be suppressed.

When the adhesive film 15 is formed, the resin composition is applied onto a release substrate by using a bar coater or a coating device or the like which forms the film into a resin, a thermosetting resin, and a cured film. The agent, the conductive particles, and the like are dissolved in a solvent. Then, the composition on the release substrate is dried using a heating furnace, a heating and drying device, or the like, whereby an adhesive film 15 having a predetermined size is obtained.

The thickness of the subsequent film 15 is appropriately set in consideration of the relationship with the thickness of the finger electrodes 12. The thickness of the subsequent film 15 is set, for example, such that the ratio of the thickness of the finger electrode 12 to the thickness of the adhesive film 15 is in the range of 1:5 to 6:5. Further, the width of the adhesive film 15 is set to be smaller than the width of the connecting wire 3. For example, when the width of the connecting wire 3 is about 1.5 mm, the width of the adhesive film 15 is set to about 1.2 mm.

Next, a method of connecting the solar cell 2 and the connection line 3 will be described.

When the solar battery cell 2 and the connection wire 3 are connected, first, the adhesive film 15 is attached along the arrangement region P of the connection line 3 of each of the light-receiving surface 2a side and the back surface 2b. Then, the connecting wire 3 is temporarily fixed to the adhesive film 15. As the connecting wire 3, for example, a connecting wire which covers a surface of a copper ribbon and has a width of about 1.5 mm by a conductive member such as solder is used, but the present invention is not limited thereto. It can be a connecting wire whose surface is not covered with solder. When a connecting wire having a coating layer of a conductive member on the surface is used, the conductive member and the finger are used The electrodes are in contact to obtain electrical conduction.

After temporarily fixing the connecting wire 3, as shown in FIG. 4, the connecting wire 3 and the solar battery cell 2 are thermocompression bonded, for example, using a thermocompression bonding machine K. In Fig. 4, a cross section in which the arrangement region P of the connecting wire 3 is cut along the longitudinal direction is illustrated. The thermocompression bonding machine K has a pair of flat pressing members 21 that face the light receiving surface 2a side and the back surface 2b side of the solar battery cell 2. The width of the pressing member 21 becomes a width wider than the width of the connecting wire 3. By making the width of the pressing member 21 wider than the width of the connecting wire 3, the pressure applied to the arrangement region P of the connecting wire 3 is uniformized.

Further, by applying pressure, the adhesive film 15 is pressed to the uneven surface formed by the finger electrodes 12, and the finger electrodes 12 are arranged on the light receiving surface 2a. By such pressing of the uneven surface, the resin of the adhesive film 15 is sufficiently removed at the time of pressure bonding, so that the connection of the finger electrode 12 and the connecting wire 3 is satisfactorily achieved. When a connecting wire having a coating layer of a conductive member on the surface is used, the conductive member may contact a part of the side surface of the finger electrode, but it is preferable to perform crimping in such a manner that the conductive member The contact of the side surface of the finger electrode is controlled within a range of 1/2 or less of the thickness of the finger electrode from the end surface of the finger electrode opposite to the substrate 11. In other words, it is preferable that the pressure contact between the light-receiving surface 2a of the substrate 11 after pressure bonding and the surface of the cladding layer facing the light-receiving surface 2a is larger than that of the finger electrodes. 1/2 of the thickness.

At the time of thermocompression bonding, the temperature of the pressurizing member 21 is set to about 80 ° C to 320 ° C, and the pressure applied to the arrangement region P of the connecting wire 3 is 1.0 MPa. The following ways to give pressure. Thereby, the connection of the connection line 3 on the light-receiving surface 2a side and the connection of the connection line 3 on the back surface 2b side can be simultaneously performed. The time for applying pressure is preferably from about 1 second to about 30 seconds. Further, the pressure to be applied is preferably 0.8 MPa or less, more preferably 0.5 MPa or less. Further, the pressure to be applied is preferably 0.1 MPa or more.

Further, at the time of thermocompression bonding, it is preferred to blow hot air to the adhesive film 15 to promote curing of the adhesive. The temperature of the hot air is preferably a temperature higher than the curing temperature of the adhesive film 15, and is set, for example, to about 80 ° C to 320 ° C. Further, the blowing time of the hot air is preferably, for example, about 1 second to 50 seconds. For the blowing of hot air, it is preferable to use a hot air supply nozzle (nozzle). By arranging the plurality of hot air supply nozzles along the longitudinal direction of the adhesive film 15, the uniformity of curing of the adhesive film 15 can be improved.

As described above, in the solar cell module manufacturing method, the connection line 3 is directly connected to the finger electrodes 12 via the adhesive film 15 in the so-called solar cell 2 having no bus bar electrodes. In this method, when the pressure from the pressing member 21 is applied to the connecting wire 3, the adhesive film 15 is pressed to the uneven surface constituted by the finger electrodes 12, and the finger electrodes 12 are arranged on the light receiving surface 2a. . Therefore, even if the pressing member 21 having a width wider than the line width of the connecting wire 3 is pressed at a low pressure of 1.0 MPa or less uniformly, the resin of the adhesive film 15 can be sufficiently ensured at the time of pressure bonding. It is possible to prevent the solar cell unit 2 from being broken and to achieve a good connection.

In the present embodiment, the finger electrodes 12 have a thickness of 10 μm to 30 μm and a width of 5 μm to 90 μm. Further, the ratio of the thickness of the finger electrode 12 to the thickness of the adhesive film 15 is in the range of 1:5 to 6:5. By satisfying this range, The uneven surface formed by the finger electrodes 12 is sufficiently formed on the adhesive film 15. Therefore, the repellent property of the resin at the time of crimping can be more fully ensured.

[Second Embodiment]

FIG. 5 is a plan view showing a light receiving surface side of the solar battery cell to which the solar battery module manufacturing method according to the second embodiment of the present invention is applied. As shown in FIG. 5, the second embodiment is different from the first embodiment in that a bus bar electrode 33 that connects the finger electrodes 12 is provided on the light receiving surface 32a side of the solar battery cell 32. .

The bus bar electrode 33 is disposed linearly substantially perpendicular to the finger electrode 12 so as to straddle all of the finger electrodes 12 on the light receiving surface 32a along the arrangement region P of the connection line 3. The bus bar electrode 33 is formed by applying and heating a metal paste similarly to the bus bar electrode 13 on the back surface 2b side. The thickness of the bus bar electrode 33 is, for example, 10 μm to 30 μm. Further, the width of the bus bar electrode 33 is smaller than the width of the bus bar electrode 13, and is, for example, 90 μm or less, preferably 5 μm to 90 μm.

In the second embodiment, after the connection line 3 is temporarily fixed, as shown in FIG. 6, the connection line 3 and the solar battery unit 2 are thermocompression bonded, for example, using a thermocompression bonding machine K. In Fig. 6, a cross section in which the arrangement region P of the connection line 3 is cut in a direction orthogonal to the longitudinal direction is illustrated. As shown in FIG. 6, by using the pressurizing member 21 having a width wider than the width of the connecting wire 3, thermocompression bonding is performed, and the arrangement region of the connecting wire 3 can be improved as in the case of the first embodiment. The uniformity of the pressure applied by P.

Moreover, by imparting pressure, the adhesive film 15 is narrower than the next The bus bar electrode 33 of the film 15 is partially pressed. By such local pressing, the resin of the adhesive film 15 is sufficiently removed at the time of pressure bonding, and the connection between the bus bar electrode 33 and the connecting wire 3 can be satisfactorily achieved.

The present invention is not limited to the embodiment described above, and various modifications can be applied. For example, in the above embodiment, the adhesive film 15 is exemplified, but it is not limited to a film-like adhesive, and a paste-like adhesive may be used. Further, in the above-described embodiment, in the thermocompression bonding machine K, the pressing member 21 is provided at the front end of a pin extending in the thickness direction of the solar battery cell 2, but may be along the solar battery unit 2. A pressing member 21 is provided at the front end of an arm extending in the surface direction.

Further, in the same manner as the solar battery unit 42 shown in FIG. 7, only a part of the finger electrodes 12 are connected by the bus bar electrode 43 on the light receiving surface 42a. In the example shown in Fig. 7, only a plurality of finger electrodes 12 located on the end side of the light receiving surface 42a are connected by the bus bar electrodes 43 having the same width as in the second embodiment. Further, the finger electrode 12 located on the center side of the light receiving surface 42a is provided with the arrangement region P of the connection line 3 so that at least a part thereof overlaps the bus bar electrode 43.

Even in such a form, the adhesive film 15 is pressed against the uneven surface formed by the finger electrodes 12, and the finger electrodes 12 are arranged on the light receiving surface 42a. Therefore, even if the pressing member 21 having a width wider than the line width of the connecting wire 3 is pressed at a low pressure of 1.0 MPa or less uniformly, the resin of the adhesive film 15 can be sufficiently ensured at the time of pressure bonding. It is possible to prevent the solar cell unit 42 from being broken and to achieve a good connection. Further, in this embodiment, the bus bar electrode 43 at the end of the light receiving surface 42a It can be used as an alignment mark when the connection line 3 is disposed, and on the other hand, the finger electrode 12 at the end of the light receiving surface 42a can be collected by the bus bar electrode 43. Therefore, the current collection efficiency of the solar cell module 1 can be prevented from being lowered.

[Examples]

Hereinafter, embodiments of the invention will be described. In the present embodiment, the solar cell module and the connection line are connected by the method for manufacturing the solar cell module of the first to fifth embodiments and the comparative example 1 to the third embodiment, and the unit of the solar cell module is connected. Whether or not cracking occurred and connection reliability was evaluated.

Use an infrared camera to check if the unit is broken. After connecting the cable to the solar cell unit, a current of 5 A flows through to cause the solar cell unit to emit light to acquire an image. The case where the following phenomenon is not observed is regarded as A, and the case where the following phenomenon is confirmed is regarded as B, which is 50 μm or more in the range of 10 mm or less from both end portions of the connecting line. The unit having a width of 0.1 μm or more is broken.

In evaluating the reliability of the connection, a solar simulator (WXS-2000S-20CH, AM1.5G manufactured by Wacom Electric Co., Ltd.) was used. After connecting the cable to the solar cell unit, the solar cell is used to measure the fill factor of the solar cell module at the initial stage of connection, and the case where the fill factor is 70 or more is regarded as A, and the fill factor is less than 70. Considered B.

[Example 1]

In Example 1, 25 parts by mass of a phenolic resin (PKHC manufactured by Union Carbide Co., Ltd.) and 10 parts by mass of an acrylic rubber were used. (acrylic rubber) a resin obtained by dispersing fine particles in a bisphenol A-type epoxy resin (containing 17% by mass of acrylic fine particles, epoxy equivalent of 220 to 240), and 10 parts by mass of cresol novolac (cresol novolac) ) epoxy resin (epoxy equivalent: 163 to 175), 10 parts by mass of silica fine particles KMP-605 (manufactured by Shin-Etsu Chemical Co., Ltd., average particle diameter: 2 μm), and 10 parts by mass of nickel Conductive particles (NiPF-BQ manufactured by Fukuda Metal Foil Co., Ltd., average particle diameter: 5 μm), and 55 parts by mass of a curing agent (made by Asahi Kasei Kogyo Co., Ltd.: microcapsules having an average particle diameter of 5 μm) a masterbatch type curing agent in which a unit type curing agent is dispersed in a liquid bisphenol F type epoxy resin, the microcapsule unit type curing agent is an imidazole modified body as a core, and is encapsulated by a polyurethane. The surface was coated to prepare an adhesive film.

Then, the adhesive film was applied to a peel-treated polyethylene terephthalate (PET) using a bar coater, and dried in an oven at 80 ° C for 5 minutes to prepare a thickness of 25 μm. Then the film is applied. Subsequently, the obtained adhesive film was cut into a width of 1.2 mm.

After the adhesive film was prepared, a 5 inch (inch) solar cell unit (125 mm × 125 mm, thickness: 200 μm) was prepared, and 57 finger electrodes (thickness 20 μm, width 0.1 mm) were formed on the light-receiving surface of the 5 吋 solar battery cell. ), and two bus bar electrodes (width 2 mm) are formed on the back surface. Next, the adhesive film was attached to the finger electrodes of the light receiving surface and the bus bar electrodes of the back surface, and the connecting wires having a width of 1.5 mm were temporarily fixed. Then, using a hot-pressing machine for solar cells (HBS02608, manufactured by Shibaura MECHATRONICS Co., Ltd.), The solar cell module of Example 1 was obtained by thermocompression bonding at a temperature of 180 ° C, a pressure of 1.0 MPa, and a pressure bonding time of 10 seconds to thereby connect the solar cell to the connecting wire.

[Embodiment 2]

An adhesive film was produced in the same manner as in Example 1. For the thermocompression bonding of the connecting wires, a welding device (a simple joint welding device NTS-150-Ms manufactured by NPC Co., Ltd.) which is improved for the connection of the connecting wires is used. In this device, the tip end portion of the pressurizing pin arranged along the longitudinal direction of the connecting wire is connected by a pressing member having a width wider than the line width of the connecting wire, and the connecting member is disposed by the pressing member. Pressurization of the area. Using this apparatus, the solar cell module of Example 2 was obtained under the conditions of a stage temperature of 170 ° C, a hot air temperature of 200 ° C, a pressure of 0.3 MPa, and a connection time of 3 seconds.

[Example 3]

In the same manner as in Example 2, except that 30 parts by mass of conductive particles of the solder (Sn96.5-Ag3.5 manufactured by Mitsui Mining and Mining Co., Ltd., average particle diameter: 10 μm) were used in the production of the adhesive film. Example 3 solar cell module.

[Example 4]

In the same manner as in Example 2, except that 30 parts by mass of conductive particles of nickel (Bright 25NR20-MX, manufactured by Nippon Chemical Industry Co., Ltd., average particle diameter: 20 μm) were used in the production of the adhesive film. Solar battery module.

[Example 5]

When the adhesive film is produced, conductive particles are not used, and besides The solar cell module of Example 5 was obtained in the same manner as in Example 2.

[Comparative Example 1]

An adhesive film was produced in the same manner as in Example 1. After the adhesive film was prepared, 5 吋 solar cell units (125 mm × 125 mm, thickness 200 μm) were prepared, and 57 finger electrodes (width 0.1 mm) and 2 bus bars were formed on the light receiving surface of the 5 吋 solar battery cell. The electrode (width 2.0 mm) was formed with two bus bar electrodes (width 2 mm) on the back surface. Further, in the same manner as in the second embodiment, the solar cell unit and the connection line were connected, and the solar cell module of Comparative Example 1 was obtained.

[Comparative Example 2]

A solar cell module of Comparative Example 2 was obtained in the same manner as in Comparative Example 1, except that the conductive particles were not used in the production of the adhesive film.

[Comparative Example 3]

A solar battery module of Comparative Example 3 was obtained in the same manner as in Comparative Example 1, except that the pressure at the time of thermocompression bonding by a thermocompression bonding apparatus for a solar cell was 2.0 MPa.

[Comparative Example 4]

A solar battery module of Comparative Example 4 was obtained in the same manner as in Example 1 except that the connection pressure was 2.0 MPa.

[Effect Confirmation Test Results]

Table 1 is a graph showing the results of the effect confirmation test of the examples. Moreover, Table 2 is a figure which shows the result of the effect confirmation test of a comparative example. As shown in Table 1, it was confirmed that in the first to fifth embodiments, no cell rupture occurred in the solar cell unit. Excellent performance at the initial connection. Further, it has been confirmed that, by setting the connection pressure to 1.0 MPa or less, the connection of the connection line (the solder coating layer of the connection line) to the side surface of the finger electrode is controlled to be referred to as the finger from the upper end of the finger electrode. Within the range of 1/2 or less of the thickness of the electrode. On the other hand, as shown in Table 2, it was confirmed that in Comparative Example 1 and Comparative Example 2, since the thermocompression bonding was performed at a low pressure of 1.0 MPa or less, cell breakage did not occur in the solar cell, but the value of the fill factor was low. Compared with Example 1 to Example 5, the performance of initial connection was poor. Further, it was confirmed that in Comparative Example 3 in which thermocompression bonding was performed at a high pressure of 2.0 MPa, cell breakage occurred in the solar cell. Further, it was confirmed that in Comparative Example 4, the contact line (the solder coating layer included in the connection line) reached the range of 1/2 of the thickness of the finger electrode from the upper end of the finger electrode to the side surface of the finger electrode. The short circuit current value drops. Such a decrease in the value of the short-circuit current is considered to be because the space formed between the light-receiving surface of the solar cell and the connection line is narrow, and the amount of resin excluded from both ends of the connection line is increased.

Table 2

Claims (15)

A method for manufacturing a solar cell module, which is a method for manufacturing a solar cell module in which a finger electrode and a connecting wire are connected by using an adhesive film, wherein the finger electrodes are arranged on a light receiving surface of a solar cell unit, wherein a bus bar electrode that connects the finger electrodes is not provided on the light receiving surface of the solar battery cell, and the arrangement region of the connecting wires on the finger electrodes is via the adhesive film The connection line is disposed, and a pressure member having a width wider than a line width of the connection line is used, and a pressure of 1.0 MPa or less is applied to the arrangement area of the connection line, and the connection line is thermocompression bonded. The method of manufacturing a solar cell module according to claim 1, wherein the connecting line is disposed so as to straddle all of the finger electrodes on the light receiving surface. The method for manufacturing a solar cell module according to the first or second aspect of the invention, wherein the finger electrode has a thickness of 10 μm to 30 μm and a width of 5 μm to 90 μm. The method for manufacturing a solar cell module according to claim 1 or 2, wherein a ratio of a thickness of the finger electrode to a thickness of the adhesive film is in a range of 1:5 to 6:5. . A method for manufacturing a solar cell module, which is a method for manufacturing a solar cell module in which a finger electrode and a connecting wire are connected by using an adhesive film, wherein the finger electrodes are arranged on a light receiving surface of a solar cell unit, wherein a light receiving surface of the solar battery cell having a width narrower than a width of the adhesive film, and a bus bar electrode connecting the finger electrodes, the connecting wire on the bus bar electrode In the arrangement region, the connection line is disposed via the adhesive film, and a pressure member having a width wider than a line width of the connection line is used, and a pressure of 1.0 MPa or less is applied to the arrangement region of the connection line. The connecting wire is thermocompression bonded. The method of manufacturing a solar cell module according to claim 5, wherein the connecting line is disposed so as to straddle all of the finger electrodes on the light receiving surface. The method of manufacturing a solar cell module according to claim 5, wherein the bus bar electrode has a width of 90 μm or less. The method for manufacturing a solar cell module according to claim 5, wherein the bus bar electrode has a thickness of 10 μm to 30 μm and a width of 5 μm to 90 μm. A method for manufacturing a solar cell module, which uses an adhesive film to connect fingers A method of manufacturing a solar cell module in which a finger electrode is arranged on a light receiving surface of a solar cell unit, wherein the light receiving surface of the solar cell unit is only on the light receiving surface a bus bar electrode that connects the finger electrodes with a width narrower than a width of the adhesive film on the end side, the said electrode on the finger electrode on the center side of the light receiving surface In the arrangement area of the connection line, the connection line is disposed via the adhesive film so that at least a part thereof overlaps the bus bar electrode, and a pressing member having a width wider than a line width of the connection line is used. A pressure of 1.0 MPa or less is applied to the arrangement area of the connection line, and the connection line is thermocompression bonded. The method for manufacturing a solar cell module according to claim 9, wherein the finger electrodes have a thickness of 10 μm to 30 μm and a width of 5 μm to 90 μm. The method for manufacturing a solar cell module according to claim 9 or claim 10, wherein a ratio of a thickness of the finger electrode to a thickness of the adhesive film is in a range of 1:5 to 6:5 . The method of manufacturing a solar cell module according to the invention of claim 9, wherein the bus bar electrode has a width of 90 μm or less. The solar cell module according to claim 9 or claim 10 The manufacturing method, wherein the bus bar electrode has a thickness of 10 μm to 30 μm and a width of 5 μm to 90 μm. The method for manufacturing a solar cell module according to any one of claims 1, 2, 5, 6, 9, or 10, wherein a pressure of 0.5 MPa or less is applied to an arrangement region of the connection line, and The connecting wire is thermocompression bonded. The method for producing a solar cell module according to any one of claims 1, 2, 5, 6, 9, or 10, wherein a conductive adhesive film or an insulating property is used as the adhesive film. Membrane film.