阅读说明：本技术 太阳能电池组件的制造方法 (Method for manufacturing solar cell module ) 是由 曾谷直哉 津村信也 吉岭幸弘 于 2020-08-28 设计创作，主要内容包括：本发明提供一种太阳能电池组件的制造方法,在层压工序中,抑制层叠体的温度偏差,能够对层叠体均匀加热。实施方式的一例的太阳能电池组件的制造工序包括层压工序,将重叠太阳能电池组件的构成部件而成的层叠体送入腔室内并载置在热板上,一边通过按压部件加压一边进行加热。在层压工序中,在将层叠体送入到腔室内之前的待机状态下,使按压部件的至少要与层叠体抵接的部分整体处于与上腔室接触、或者与热板接触、或者与上腔室和热板不接触的任一种状态,来控制按压部件的温度。(The invention provides a method for manufacturing a solar cell module, which can restrain temperature deviation of a laminated body in a laminating process and can uniformly heat the laminated body. The process for manufacturing a solar cell module according to an example of the embodiment includes a laminating step of placing a laminated body in which the components of the solar cell module are stacked in a chamber and on a hot plate, and heating the laminated body while pressing the laminated body with a pressing member. In the laminating step, in a standby state before the laminate is fed into the chamber, the temperature of the pressing member is controlled by bringing at least a portion of the pressing member to be in contact with the laminate into contact with the upper chamber as a whole, or into contact with the hot plate, or into non-contact with the upper chamber and the hot plate.)

1. A method for manufacturing a solar cell module, comprising:

comprises a laminating step of feeding a laminate, in which components of a solar cell module are stacked, into a chamber having an upper chamber provided with a pressing member and a lower chamber provided with a heat plate, placing the laminate on the heat plate, and heating the laminate while applying pressure by the pressing member,

in the laminating step, in a standby state before the laminated body is fed into the chamber, the temperature of the pressing member is controlled by bringing at least a portion of the pressing member to be brought into contact with the laminated body into a state in which the entire portion is brought into contact with the upper chamber, or is brought into contact with the hot plate, or is not brought into contact with the upper chamber and the hot plate.

2. The method for manufacturing a solar cell module according to claim 1, wherein:

in the laminating step, in the standby state, the entire portion of the pressing member to be brought into contact with at least the stacked body is brought into contact with the upper chamber or the hot plate, and the temperature of the pressing member is controlled.

3. The method for manufacturing a solar cell module according to claim 1, wherein:

in the laminating step, in the standby state, at least the entire portion of the pressing member to be brought into contact with the laminated body is brought into contact with the upper chamber or into non-contact with the upper chamber and the heat plate, and then the entire portion to be brought into contact with the laminated body is brought into contact with the heat plate for a predetermined time, and then the laminated body is fed into the chamber.

4. The method for manufacturing a solar cell module according to claim 1, wherein:

in the laminating step, in the standby state, at least the entire portion of the pressing member to be brought into contact with the laminated body is brought into contact with the upper chamber, and then the entire portion to be brought into contact with the laminated body is brought into contact with the hot plate for a predetermined time, and then the laminated body is fed into the chamber.

Technical Field

The present disclosure relates to a method for manufacturing a solar cell module, and more particularly, to a method for manufacturing a solar cell module including a lamination process.

Background

Solar modules generally comprise: a solar cell string in which a plurality of solar cells are connected by a wiring member; two base materials which hold the cell string; and a filler which is filled between the base materials and seals the solar cells. For example, patent document 1 discloses a method for manufacturing a solar cell module, which includes a laminating step of laminating and thermocompression-bonding a glass substrate, a resin sheet constituting a 1 st filler, a solar cell string, a resin sheet constituting a 2 nd filler, and a back sheet from a light-receiving surface side of the module. In the laminating step, the laminated body on which the constituent members of the solar cell module are laminated is compressed using a pressing member made of elastic rubber.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2013-118321

Disclosure of Invention

Problems to be solved by the invention

However, in the above lamination process, for example, in order to prevent the 2 nd filler from being entangled into the light receiving surface side of the solar cell while maintaining good adhesion between the filler and the base material, it is necessary to control the temperature of the laminate so that the laminate is uniformly heated at a target temperature. However, the temperature of the pressing member for compressing the laminate varies, and as a result, the laminate may not be uniformly heated, which may affect the quality of the product.

An object of the present disclosure is to provide a method for manufacturing a solar cell module, which can suppress temperature variation of a laminate and can uniformly heat the laminate in a lamination process.

Means for solving the problems

In one aspect of the present disclosure, there is provided a method for manufacturing a solar cell module, including a laminating step of feeding a laminated body in which constituent members of the solar cell module are stacked into a chamber having an upper chamber provided with a pressing member and a lower chamber provided with a hot plate, placing the laminated body on the hot plate, and heating the laminated body while applying pressure by the pressing member, wherein in the laminating step, in a standby state before the laminated body is fed into the chamber, the temperature of the pressing member is controlled by bringing at least a portion of the pressing member to be brought into contact with the laminated body into a state of being in contact with the upper chamber, or in contact with the hot plate, or in a state of not being in contact with the upper chamber and the hot plate as a whole.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the method for manufacturing a solar cell module of the present disclosure, in the lamination step, the temperature variation of the laminate can be suppressed, and the laminate can be uniformly heated. As a result, a solar cell module having good quality can be stably manufactured.

Drawings

Fig. 1 is a sectional view of a solar cell module as an example of the embodiment.

Fig. 2 is a diagram showing a structure of a laminating apparatus for manufacturing a solar cell module according to an example of the embodiment.

Fig. 3 is a diagram showing a lamination process according to an example of the embodiment.

Fig. 4 is a diagram showing the pressure P acting on the laminate, the temperature T of the laminate, and the loss elastic modulus G2 of the filler in the lamination step of one example of the embodiment.

Fig. 5 is a diagram showing a laminating step according to another example of the embodiment.

Fig. 6 is a diagram showing a laminating step according to another example of the embodiment.

Fig. 7 is a diagram for explaining a laminating process of the related art.

Description of the reference numerals

1 laminating apparatus

10 solar cell module

11 solar cell

12 glass substrate

13 Back sheet

14 st filling material

15 No. 2 Filler Material

16 laminated body

20 chamber

21 upper chamber

21a upper chamber

22 metal plate

22a, 26a vent hole

23 pressing member

25 lower chamber

25a lower chamber

26 Hot plate

30 vacuum pump

31 st pipe

32 st opening and closing valve

33 No. 1 purge valve

35 No. 2 pipe

36 nd 2 nd opening and closing valve

37 nd 2 nd air release valve

40 control device

41 processor

42 memory

Detailed Description

Embodiments of the method for manufacturing a solar cell module according to the present disclosure will be described in detail below with reference to the drawings. The embodiments described below are merely examples, and the manufacturing method of the present disclosure is not limited thereto. The drawings referred to in the embodiments are schematic only, and the dimensional ratios of components and the like depicted in the drawings should be determined in consideration of the following description.

Fig. 1 is a cross-sectional view showing a solar cell module 10 as an example of the embodiment. As shown in fig. 1, the solar cell module 10 includes a solar cell 11, a glass substrate 12 (1 st substrate) covering a light-receiving surface of the solar cell 11, and a back sheet 13 (2 nd substrate) covering a back surface of the solar cell 11. The 1 st base material disposed on the light-receiving surface side of the solar cell 11 may be a resin base material, and the 2 nd base material disposed on the back surface side of the solar cell 11 may be a glass base material. The solar cell module 10 has, for example, a rectangular shape in plan view, but the shape may be appropriately changed, and may be a square shape, a pentagonal shape, or the like in plan view.

Here, the "light receiving surface" of the solar cell 11 refers to a surface on which light is mainly incident, and the "back surface" refers to a surface opposite to the light receiving surface. More than 50%, for example, 80% or more or 90% or more of the light incident on the solar cell 11 is incident from the light receiving surface side. The terms light-receiving surface and back surface are used for the solar cell module 10, the photoelectric conversion portion described below, and the like as well.

The solar cell module 10 includes a 1 st filler 14 filled between the solar cells 11 and the glass substrate 12, and a 2 nd filler 15 filled between the solar cells 11 and the back sheet 13. The solar cell 11 is sandwiched between the glass base 12 and the back sheet 13 and sealed with the 1 st filler 14 and the 2 nd filler 15. In the example of fig. 1, two solar cells 11 are shown, but the number of solar cells 11 included in the solar cell module 10 is not particularly limited. The solar cell module 10 generally includes a plurality of solar cells 11, and a cell string of the solar cells 11 is formed by connecting adjacent solar cells 11 in series by a wiring member not shown.

The solar cells 11 each include a photoelectric conversion portion that generates carriers by receiving sunlight and a collector electrode that is provided on the photoelectric conversion portion and collects carriers. The photoelectric conversion portion has, for example, a substantially square shape in which four corners are obliquely cut off in a plan view. Examples of the photoelectric conversion part include a semiconductor substrate made of crystalline silicon (Si), gallium arsenide (GaAs), indium phosphide (InP), or the like, and an amorphous semiconductor layer formed on the semiconductor substrate, or a transparent conductive layer formed on a doped layer formed by thermal diffusion or the like.

For example, the collector electrode is composed of a light-receiving surface electrode formed on the light-receiving surface of the photoelectric conversion portion and a back surface electrode formed on the back surface of the photoelectric conversion portion. The collector electrode preferably comprises a plurality of finger electrodes. The plurality of sub-gate electrodes are thin line-shaped electrodes formed substantially parallel to each other. The collector electrode may further include a main finger electrode having a width greater than the finger electrodes and substantially orthogonal to each finger electrode. The back surface electrode may cover substantially the entire back surface of the photoelectric conversion portion.

The glass base material 12 covers the entire cell string of the solar cells 11, and protects the solar cells 11 from external impact, moisture, and the like. The glass substrate 12 preferably has a high total light transmission, for example, 80% to 100%, or 85% to 95%. The total light transmittance was measured based on JIS K7361-1 (test method of total light transmittance of plastic-transparent material-part 1: single beam method).

As with the glass substrate 12, a light-transmitting substrate may be used for the back sheet 13, and an opaque substrate may be used for the back sheet 13. The total light transmittance of the back sheet 13 is not particularly limited, and may be 0%. For example, from the viewpoint of weight reduction of the module, a resin sheet having a thickness smaller than that of the glass base material 12 is used for the back sheet 13.

The 1 st filler 14 and the 2 nd filler 15 are composed mainly of a softened or melted resin in the laminating step described later. Each filler material may contain an antioxidant ultraviolet absorber or the like. The 1 st filler 14 is made of a colorless transparent resin having a high total light transmittance. On the other hand, the 2 nd filling material 15 may contain a colorant such as a white pigment. The white pigment such as titanium oxide has a function of reflecting sunlight to increase the incident light of the solar cell 11.

Examples of the resin constituting the first filler 14 include polyolefins (for example, polyethylene, polypropylene, and random or block copolymers of ethylene and α -olefins having 3 to 20 carbon atoms) obtained by polymerizing at least one selected from ethylene and α -olefins, polyesters, polyurethanes, epoxy resins, and copolymers of ethylene and vinyl carboxylates, acrylates, and other vinyl monomers (for example, ethylene-vinyl acetate copolymers).

The 1 st filler 14 preferably contains a thermosetting resin. The thermosetting resin is a crosslinkable resin containing a crosslinking component, a crosslinking agent, and the like, which undergo a crosslinking reaction by heating. As the resin constituting the 1 st filler 14, a crosslinkable polyolefin (hereinafter, referred to as "POE") is particularly preferable. Since the POE is used as the first filling material 14, good sealing performance is obtained, and the reliability of the solar cell module 10 is improved.

The crosslinking initiation temperature of the No. 1 filler material 14 is, for example, 135 ℃ to 140 ℃ and may be more than 140 ℃. The crosslinking initiation temperature is a temperature at which crosslinking proceeds to some extent in a time of 60 seconds to 600 seconds, which is a time of the laminating step. In the present embodiment, the loss tangent (tan δ ═ G2/G1, G1: storage modulus, G2: loss elastic modulus) measured by curing torque (JIS K6300-2) is a temperature falling to 1 or less in about 10 minutes.

The 2 nd filler 15 may be composed of the same resin as the 1 st filler 14, but is preferably composed of a different resin from the 1 st filler 14. The 2 nd filling material 15 preferably contains a thermosetting resin. As the resin constituting the second filler 15, a crosslinkable ethylene-vinyl acetate copolymer (hereinafter, referred to as "EVA") is particularly preferable. EVA contains organic peroxides such as benzoyl peroxide, dicumyl peroxide, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane, etc. as a crosslinking agent.

The crosslinking initiation temperature of the 2 nd filler 15 may be lower than the crosslinking initiation temperature of the 1 st filler 14, and may be 120 to 130 ℃. The viscosity of each filler at the time of heating in the laminating step is not particularly limited, but when the above-mentioned filler is used for each filler, the viscosity of the 2 nd filler 15 before the start of curing is generally higher than the viscosity of the 1 st filler 14 before the start of curing. The 1 st filler material 14 and the 2 nd filler material 15 flow in, for example, a lamination process, and have fluidity of the 1 st filler material 14 > the 2 nd filler material 15.

The 1 st and 2 nd filler materials 14 and 15 preferably contain a coupling agent. By using the coupling agent, the adhesion force between the solar cells 11, the glass substrate 12, and the back sheet 13 and the respective fillers can be improved, and interface peeling can be more easily suppressed. Examples of the coupling agent include silane coupling agents, titanate coupling agents, and aluminate coupling agents. Among them, a silane coupling agent is particularly preferable. Examples of the silane coupling agent include vinyltriethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-methacryloxypropyltrimethoxysilane, and the like.

Next, a method for manufacturing the solar cell module 10 will be described in detail with reference to fig. 2 to 6. Fig. 2 is a diagram showing a configuration of a laminating apparatus 1 according to an example of the embodiment. Fig. 3 is a diagram illustrating a lamination process of the solar cell module 10 according to an example of the embodiment. For comparison, fig. 7 shows a conventional example of the laminating step.

The manufacturing process of the solar cell module 10 includes a lamination process. The solar cell module 10 is manufactured through a lamination process shown in fig. 3, for example. The lamination step is a step of thermocompression bonding the laminate 16 on which the constituent members of the solar cell module 10 are superimposed, and can be performed using the lamination apparatus 1 illustrated in fig. 2.

The process for manufacturing the solar cell module 10 may further include a curing step of heat-treating the laminate 16 after the lamination step. In the curing step, the laminated body 16 is preferably heat-treated at a temperature higher than that in the laminating step or for a long time to cause a crosslinking reaction of the respective fillers and a reaction of the silane coupling agent. The heating furnace for performing the curing step is not particularly limited as long as it can feed the laminate 16, and for example, a resistance heating furnace can be used.

As illustrated in fig. 2, the laminating apparatus 1 includes: a chamber 20 for performing thermocompression bonding of the stacked body 16, a vacuum pump 30 for evacuating the chamber 20, and a control device 40 for controlling operations of the chamber 20, the vacuum pump 30, and the like. The chamber 20 includes an upper chamber 21 and a lower chamber 25, and has a structure in which an internal space is opened and closed by moving the upper chamber 21 in the vertical direction. The inner space of the chamber 20 is a vacuum chamber that can be evacuated by the vacuum pump 30. The 1 st pipe 31 connected to the vacuum pump 30 is connected to the upper chamber 21, and the 2 nd pipe 35 connected to the vacuum pump 30 is connected to the lower chamber 25.

The upper chamber 21 includes a top surface portion and a side surface portion, and is open downward. The upper chamber 21 moves downward and comes into contact with the upper surface of the lower chamber 25, thereby sealing the internal space of the chamber 20. The upper chamber 21 has a metal plate 22 formed with a vent hole 22a and a pressing member 23 for compressing the stacked body 16. The metal plate 22 and the pressing member 23 are fixed to, for example, a side surface portion of the upper chamber 21. The metal plate 22 is, for example, a perforated metal plate, and prevents the pressing member 23 from sticking to the inlet of the 1 st pipe 31. The temperature of the metal plate 22 is, for example, 30 to 70 ℃ (higher than room temperature and lower than the temperature of the hot plate 26).

The pressing member 23 is attached to the metal plate 22 below the upper chamber 21 so as to close the opening of the upper chamber 21. Therefore, the internal space of the chamber 20 is partitioned into an upper chamber 21a and a lower chamber 25a by the pressing member 23. The lower chamber 25a is formed to move the upper chamber 21 downward and close the chamber 20. The stacked body 16 is disposed in the lower chamber 25 a. The pressing member 23 presses the stacked body 16 from above using a heat-resistant rubber-like member such as elastic silicone rubber. The pressing member 23 is generally called a diaphragm (diaphragm).

The lower chamber 25 has a heater comprising a hot plate 26. In the example shown in fig. 2, a vent hole 26a is formed around the hot plate 26. The heat plate 26 has a size capable of placing one or more stacks 16, and the stacks 16 fed into the chamber 20 are disposed on the upper surface of the heat plate 26. The temperature of the hot plate 26 is set to, for example, a temperature equal to or higher than the crosslinking start temperature of the 1 st filler 14 (140 to 170 ℃ for example).

As described above, the laminating apparatus 1 includes the 1 st pipe 31 and the 2 nd pipe 35. The 1 st pipe 31 is provided with a 1 st opening/closing valve 32 and a 1 st purge valve 33, and the 2 nd pipe 35 is provided with a 1 st opening/closing valve 36 and a 2 nd purge valve 37. For example, the vacuum pump 30 is operated to open the 1 st opening/closing valve 32, thereby evacuating the upper chamber 21 a. After the 1 st opening/closing valve 32 is closed in a vacuum state, the degree of vacuum of the upper chamber 21a can be adjusted by operating the 1 st purge valve 33, and the upper chamber 21a can be returned to the atmospheric pressure. The lower chamber 25a can also be similarly adjusted in vacuum degree or the like using the 2 nd opening/closing valve 36 and the 2 nd purge valve 37.

The controller 40 controls the vertical movement mechanism of the upper chamber 21, the heater of the lower chamber 25, the vacuum pump 30, the operations of the valves, and the like. The control device 40 is constituted by a computer provided with a processor 41, a memory 42, an input/output interface, and the like. The processor 41 is constituted by, for example, a CPU or a GPU, and executes a control program by reading it to execute a manufacturing process described later. The memory 42 includes nonvolatile memory such as ROM, HDD, SSD, and volatile memory such as RAM. The control program is stored in the nonvolatile memory.

As illustrated in fig. 3, the lamination step is a step of feeding the laminate 16 into a chamber 20 having an upper chamber 21 provided with a pressing member 23 and a lower chamber 25 provided with a hot plate 26, placing the laminate on the hot plate 26, and heating the laminate while pressurizing the laminate with the pressing member 23. The laminate 16 has a structure in which, for example, the glass base 12, the 1 st filler 14, the cell string of the solar cells 11, the 2 nd filler 15, and the back sheet 13 are laminated in this order from the hot plate 26 side.

In the laminating step, after the laminated body 16 is fed into the chamber 20, the upper chamber 21 is closed and the laminated body 16 is thermally pressed by the pressing member 23, and thereafter, the upper chamber 21 is opened again and the laminated body 16 is fed out from the chamber 20. Then, when the processed laminated body 16 is sent out from the chamber 20, the laminating process is intermittently performed to send the next laminated body 16 into the chamber 20.

In the laminating step illustrated in fig. 3, in a standby state until the laminated body 16 is loaded into the chamber 20, at least the entire portion of the pressing member 23 that abuts against the laminated body 16 (hereinafter, may be referred to as "abutting portion") is brought into contact with the upper chamber 21, and the temperature of the pressing member 23 is controlled. More specifically, the entire abutting portion of the pressing member 23 is brought into contact with the metal plate 22 of the upper chamber 21. In this case, the temperature control of the pressing member 23 can be started before the pressurized laminate 16 is sent out from the chamber 20. In the standby state illustrated in fig. 3, the chamber 20 is open, but the chamber 20 may be closed.

The pressing member 23 is in contact with the metal plate 22, and thus is generally cooled by the metal plate 22. Since the pressing member 23 is in contact with the hot plate 26 via the stacked body 16 or a part of the pressing member is in direct contact with the hot plate 26, the temperature of the pressing member 23 is higher than that of the metal plate 22 when the laminating step is intermittently performed. On the other hand, since the metal plate 22 not in contact with the hot plate 26 is, for example, 30 to 70 ℃, the pressing member 23 in contact with the metal plate 22 is cooled to a temperature close to the temperature.

That is, in the laminating step of the present embodiment, the temperature of the pressing member 23 is controlled so that the temperature of the pressing member 23 is uniform by the metal plate 22 in the standby state. As a result, the laminated body 16 can be uniformly heated, and a solar cell module 10 having good quality can be stably manufactured. The laminating apparatus 1 may have a temperature adjusting device for maintaining the metal plate 22 at a predetermined temperature, and in this case, the pressing member 23 may be cooled or heated to a temperature close to the predetermined temperature.

As illustrated in fig. 7, in the laminating process according to the related art, temperature control of the pressing member 23 in a standby state is not performed, and for example, only a part of the pressing member 23 is in contact with the upper chamber 21 (metal plate 22), so that temperature variation occurs in the pressing member 23. As a result, the laminate 16 may not be uniformly heated, which may affect the quality of the product. In addition, it is also assumed that the temperature of the laminate 16 varies in each lamination step, and the quality of the product varies.

In the prior art, for example, after the laminate 16 is compressed for a predetermined time by the pressing member 23, the pressure bonding force is eliminated, and therefore only the lower chamber 25a is opened to the atmospheric pressure. At this time, since the exhaust valve (the 1 st opening/closing valve 32) and the 1 st purge valve 33 of the upper chamber 21a are closed, a certain amount of air (the pressure at the time of pressurization × the volume of the upper chamber at the time of pressurization) is sealed in the upper chamber 21a, and the outside of the pressing member 23 becomes the atmospheric pressure, whereby the pressing member 23 is pushed up so that the upper chamber 21a becomes also substantially the atmospheric pressure. Therefore, the position of the pressing member 23 is unstable, and a part of the pressing member 23 comes into contact with the upper chamber 21 (metal plate 22), so that the temperature of the pressing member 23 at the contact portion is greatly lowered. The contact of the pressing member 23 with the portion of the upper chamber 21 (metal plate 22) may be caused by exhausting the upper chamber 21a when the chamber 20 is closed at the time of the next lamination process. In either case, the temperature of the pressing member 23 varies. In order to suppress the temperature variation of the pressing member 23 caused by this, the temperature of the contact portion of the pressing member 23 can be controlled by maintaining the entire contact portion of the pressing member 23 in contact with the upper chamber 21 (metal plate 22), in contact with the heat plate 26, or in a state of not being in contact with the upper chamber 21 (metal plate 22) and the heat plate 26. In either case, the temperature of the pressing member 23 varies.

As a method of bringing the entire contact portion of the pressing member 23 into contact with the metal plate 22, for example, a method of operating the vacuum pump 30 and opening the 1 st opening/closing valve 32 to evacuate the upper chamber 21a by a degree of vacuum with which the entire contact portion is brought into contact with the metal plate 22 is given. Specifically, the vacuum pump 30 may be operated to open the 1 st opening/closing valve 32. Since the outer portion of the pressing member 23 is at atmospheric pressure, the pressing member 23 may be in contact with the metal plate 22 and the side surface portion of the upper chamber 21 in the standby state, substantially the entire pressing member 23.

In the laminating step of the present embodiment, in the standby state, at least the entire contact portion of the pressing member 23 may be brought into contact with the upper chamber 21 (metal plate 22), and then the laminated body 16 may be fed into the chamber 20 after bringing the pressing member 23 into contact with the hot plate 26 for a predetermined time. At this time, at least the entire abutting portion needs to be in contact with the hot plate 26. An example of the predetermined time is 5 to 60 seconds.

After the temperature of the pressing member 23 is made uniform, the temperature of the cooled pressing member 23 can be uniformly increased by contacting the hot plate 26. In this case, the stacked body 16 can be heated relatively uniformly. As a method of bringing the entire contact portion of the pressing member 23 into contact with the hot plate 26, for example, a method of closing the chamber 20 to return the upper chamber 21a to the atmospheric pressure and evacuating the lower chamber 25a may be mentioned.

Fig. 4 is a graph showing the pressure P acting on the laminated body 16, the temperature T of the laminated body 16, and the loss elastic modulus G2 of the 1 st filler 14 at each time point from the time when the laminated body 16 is fed into the chamber 20 to the time when it is fed out. The pressure Pz is a pressing force applied to the stacked body 16 by the pressing member 23. Further, thermocouples were attached to the inner surfaces of the glass base material 12 and the back sheet 13, respectively, and the measurement values of the thermocouples were averaged to determine the temperature T of the laminate 16.

In the laminating step, after the laminated body 16 is carried into the chamber 20 and disposed on the upper surface of the hot plate 26, the laminated body 16 is compressed by using the pressing member 23 whose temperature is controlled in a standby state, and the respective constituent members of the laminated body 16 are thermally pressed. The 1 st filler 14 and the 2 nd filler 15 are generally supplied in the form of resin sheets, and are heated, softened, or melted through the glass base material 12 in contact with the hot plate 26.

As shown in fig. 4, in the laminating step, the laminate 16 is heated for a predetermined time while evacuating the upper chamber 21a and the lower chamber 25a (M0 to M1), and then the pressing by the pressing member 23 is started (M1). The predetermined time (M0 to M1) is, for example, 10 seconds to 90 seconds. In the laminating step illustrated in fig. 3, it is preferable that the entire contact portion of the pressing member 23 is brought into contact with the upper chamber 21 (metal plate 22) for a predetermined time (M0 to M1).

The pressing force Pz of the pressing member 23 is, for example, at most 1atm, and is, for example, 0.6 to 1.0 atm. The laminating apparatus may also include a pressurizing mechanism of more than 1 atm. The temperature T of the laminate 16 is greatly increased by the large pressing force of the hot plate 26, and the loss elastic modulus G2 of the filler is also greatly decreased with the increase in the temperature of the laminate 16.

Further, the change in the loss elastic modulus G2 accompanying the change in temperature of each filler showed the same tendency as the change in the viscosity of the filler. In the case of a viscous elastomer, the complex elastic modulus G (G × G1+ iG2, i2 — 1) is used as a value for the elastic modulus E. The loss elastic modulus G2 is a measure of energy lost by heat generation or the like during deformation, and is an index indicating viscosity. In the present specification, the loss elastic modulus G2 of the filler is determined by dynamic viscoelasticity measurement (DMA, see the references "network polymer" vol.32, No.6(2011), p 362).

The measurement conditions of DMA are as follows.

Frequency: 10Hz

Temperature rise rate: 10 ℃/min (-50 ℃ -150 ℃ C.)

Deformation mode: stretching

In the laminating step, the pressing of the pressing member 23 is stopped at a temperature T1 at which the 1 st filler 14 maintains a predetermined loss elastic modulus G2(T1) (M2). The pressurization by the pressing member 23 can be stopped by setting the lower chamber 25a to atmospheric pressure and the upper chamber 21a to atmospheric pressure or lower. The laminate 16 is uniformly pressurized by the atmospheric pressure at the hydrostatic pressure in a temperature region where the loss elastic modulus G2 is lower than the predetermined loss elastic modulus G2(T1), whereby the 2 nd filler 15 is highly suppressed from being entangled into the light receiving surface side of the solar cell 11. The pressing time (M1 to M2) is significantly shorter than that in the laminating process of the prior art, and is, for example, 90 seconds or less.

In this case, since the lamination process of the laminated body 16 to be fed next is provided, it is preferable that the entire contact portion of the pressing member 23 is completely in contact with (or not in contact with) the metal plate 22. That is, after the pressurization by the pressing members 23 is stopped and before the pressurized laminate 16 is sent out from the chamber 20, the temperature control of the pressing members 23 can be started. In the laminating step illustrated in fig. 3, for example, the entire contact portion of the pressing member 23 is brought into (or out of) contact with the upper chamber 21 (metal plate 22) and the temperature of the pressing member 23 is controlled from the time when the pressing by the pressing member 23 is stopped (M2) to the time when the predetermined time (M0 to M1) of the next laminating step elapses.

After the pressing of the pressing member 23 is stopped, the heating is preferably continued until the temperature T of the laminated body 16 reaches a higher temperature of the respective crosslinking start temperatures of the 1 st filler 14 and the 2 nd filler 15. When the crosslinking start temperature of the 1 st filler 14 is higher than the crosslinking start temperature of the 2 nd filler 15, the heating is continued until the temperature T of the laminated body 16 reaches at least the crosslinking start temperature T2 of the 1 st filler 14 after the pressing of the pressing member 23 is stopped (M3). At this time, the laminated body 16 is pressurized by the hydrostatic pressure formed at the atmospheric pressure, and the adhesion of each filler to the solar cells 11 and the like is further increased.

The loss elastic modulus G2(T1) of the 1 st filling material 14 as the pressurization stop threshold of the pressing member 23 is preferably set to 10³Pa or more, e.g. set at 10³Pa～10⁶Pa, in the range of Pa. In the laminating step, the pressing by the pressing member 23 may be stopped when the temperature of the laminated body 16 reaches 80 to 110 ℃ or 85 to 105 ℃. Because the loss elastic modulus of the filler material used in the solar cell module 10 is generally around 110 ℃ and below 10³Pa, the rolling-in of the 2 nd filler 15 can be suppressed by stopping the pressing by the pressing member 23 with 110 ℃ as a threshold.

In the laminating step illustrated in fig. 5, in a standby state until the laminated body 16 is loaded into the chamber 20, the entire contact portion of the pressing member 23 is not in contact with the upper chamber 21 and the heat plate 26. Since the laminating process is generally intermittently continued in the production process, the temperature of the pressing member 23 at the end of pressing (M2) is, for example, T1, and the temperature can be maintained for a certain period of time as long as the pressing member does not contact the upper chamber 21 (metal plate 22). Therefore, the temperature of the pressing member 23 can be controlled to be near T1. For example, by controlling a part of the contact portion of the pressing member 23 so as not to contact the metal plate 22, temperature variation of the pressing member 23 can be suppressed. In the step illustrated in fig. 5, similarly to the step illustrated in fig. 3, the stacked body 16 is fed into the chamber 20, is arranged on the upper surface of the hot plate 26, and the stacked body 16 is compressed by the pressing member 23 whose temperature is controlled in a standby state.

As a method for keeping the entire contact portion of the pressing member 23 out of contact with the upper chamber 21 and the hot plate 26, the pressure of the upper chamber 21a may be set to be not less than the pressure of the outside of the pressing member 23, for example, the lower chamber 25 a. For example, the upper chamber 21a and the lower chamber 25a may be set to atmospheric pressure. In the example shown in fig. 5, it is preferable that substantially the entire pressing member 23 except for the fixing portion to the side surface portion of the upper chamber 21 is maintained in a state of not contacting the metal plate 22 and the hot plate 26.

In the laminating step illustrated in fig. 5, in a standby state, at least the entire contact portion of the pressing member 23 may not be in contact with the upper chamber 21 and the hot plate 26, and then the laminated body 16 may be fed into the chamber 20 after the pressing member 23 is in contact with the hot plate 26 for a predetermined time. At this time, at least the entire abutting portion needs to be in contact with the hot plate 26. An example of the predetermined time is 5 to 60 seconds.

In the laminating step illustrated in fig. 6, in a standby state until the laminated body 16 is fed into the chamber 20, more preferably immediately before the laminated body 16 is fed, the entire contact portion of the pressing member 23 is brought into contact with the hot plate 26, and the temperature of the pressing member 23 is controlled. The pressing member 23 is separated from the hot plate 26 from when the pressing of the stacked body 16 is stopped (for example, at a temperature T1) to when the next stacked body 16 is compressed, and therefore, the temperature thereof is lower than the temperature of the hot plate 26. Further, the pressing member 23 may be brought into contact with the metal plate 22 at a relatively low temperature. Therefore, the temperature of the pressing member 23 rises by the contact of the pressing member 23 and the hot plate 26.

Since the temperature of the hot plate 26 is usually set to be constant, in the laminating step illustrated in fig. 6, the temperature of the pressing member 23 is controlled so that the temperature of the pressing member 23 is uniform by the hot plate 26 in a standby state. In the step illustrated in fig. 6, similarly to the steps illustrated in fig. 3 and 5, the stacked body 16 is fed into the chamber 20, disposed on the upper surface of the hot plate 26, and the stacked body 16 is compressed by the pressing member 23 whose temperature is controlled in a standby state.

As a method of bringing the entire contact portion of the pressing member 23 into contact with the hot plate 26, for example, a method of evacuating the lower chamber 25a by making the upper chamber 21a at atmospheric pressure in a state where the chamber 20 is closed can be cited. Specifically, the vacuum pump 30 may be operated to open the 2 nd opening/closing valve 36, and the 1 st opening/closing valve 32 may be closed to fully open the 1 st purge valve 33. In the lamination process illustrated in fig. 6, the chamber 20 needs to be temporarily opened when the stacked body 16 is fed. At this time, since the upper chamber 21a is maintained at atmospheric pressure, the pressing member 23 does not contact the upper chamber 21 (metal plate 22).

In the laminating step illustrated in fig. 6, the entire contact portion of the pressing member 23 may be brought into contact with the upper chamber 21 from the time when the pressurization of the laminate 16 is stopped to the time when the processed laminate 16 is fed out. After the processed laminate 16 is sent out, the chamber 20 is closed, and the entire contact portion of the pressing member 23 is brought into contact with the hot plate 26. The time for bringing the pressing member 23 into contact with the hot plate 26 is, for example, 10 to 120 seconds. The method of fig. 6 is different from the method of fig. 6 in that the temperature controllability is optimal, but the stack 16 cannot be simultaneously fed and discharged. There is also a disadvantage that the processing time becomes long, such as the number of times of opening and closing the chamber 20 increases.

As described above, according to the manufacturing method, the temperature variation of the pressing member 23 can be suppressed in the standby state of the laminating process. As a result, temperature variation of the laminate 16 is suppressed, and a solar cell module 10 having good quality can be stably manufactured.

The above embodiments can be appropriately modified in design within a range not impairing the object of the present disclosure. For example, in the above embodiment, the first filler material 1 is maintained at 10³The laminating step in which the pressing by the pressing member 23 is stopped at a temperature at which the elastic modulus is lost at Pa or more, but the pressing by the pressing member 23 may be continued up to a higher temperature.