JP2014154628A - Method of manufacturing solar cell module - Google Patents

Abstract

Provided is a method for manufacturing a solar cell module that can be easily connected with high accuracy even in the case of a warped solar cell, and can prevent the solar cell from being displaced even during conveyance.
SOLUTION: A side edge portion of adjacent solar cells 1 is vertically moved through an unmelted solder 2a on an adhesive sheet 3 whose adhesive strength is reduced by heating when unmelted solder 2a is melted. In a state of being overlaid, the plurality of solar cells 1 are adhesively fixed and arranged. And while melting the said unmelted solder 2a by heating, the adhesive force of the adhesive sheet 3 is reduced. Then, it takes out from a heating furnace, it cools, the molten solder is solidified, and the solar cell module to which the adjacent photovoltaic cell 1 was connected by the solidified solder is obtained. And a solar cell module is peeled from the adhesive sheet 3 in which the adhesive force fell.
[Selection] Figure 2

Description

  The present invention relates to a method for manufacturing a solar cell module by connecting a plurality of solar cells.

  In general, as shown in FIG. 3, the solar cell module is configured to obtain a predetermined voltage by connecting a plurality of long plate-like solar cells 1 in series in the width direction. The connection of the solar cells 1 is made by superimposing the side edges along the longitudinal direction of the adjacent solar cells 1 up and down via a conductive bonding agent such as solder 2 that is solidified after being melted. ing.

  As a method for manufacturing such a solar cell module A, a method that facilitates manufacturing work has been proposed (see, for example, Patent Document 1). As shown in FIG. 4, first, the method uses an assembly base 30 in which a large number of steps are formed on the mounting surface of the solar battery cell 1. The battery cells 1 are placed one by one, and are arranged in the shape of the solar battery module A (see FIG. 3) in a state where the plurality of solar battery cells 1 are not connected. In this state, the side edges along the longitudinal direction of the adjacent solar cells 1 are in contact with each other up and down via the unmelted solder 2a. Next, the unmelted solder 2a is melted by conveying it to a heating furnace and heating it. Then, it is taken out from the heating furnace, the molten solder is cooled and solidified, and the plurality of solar cells 1 are connected in series by the solidified solder 2 to obtain a solar cell module A (see FIG. 3). . Thus, the manufacturing operation is facilitated by using the specific assembly base 30.

JP 2011-77148 A

  However, since the solar cell 1 is thin, warpage is likely to occur, and even if the assembly base 30 is used, the solar cell 1 in which warpage has occurred can be connected to the adjacent solar cell 1 with high accuracy. It has become difficult. In addition, during the transfer to the heating furnace, the placement position of the solar cell 1 is shifted due to minute vibrations, and there is a possibility that the solar cell 1 is connected to the adjacent solar cell 1 in the state of being shifted.

  The present invention has been made in view of such circumstances, and it is easy to connect even a solar cell with warpage with high accuracy, and the solar cell can prevent the solar cell from shifting even during transportation. The purpose is to provide a module manufacturing method.

  In order to achieve the above object, a method for producing a solar cell module according to the present invention includes a plurality of side edges of adjacent solar cells stacked vertically with an unmelted conductive adhesive interposed therebetween. A step of arranging solar cells, and a step of connecting adjacent solar cells by cooling and solidifying after heating and melting the conductive adhesive, and the plurality of solar cells are connected in series. A solar cell module manufacturing method for obtaining a solar cell module, wherein the solar cells are arranged on an adhesive sheet whose adhesive strength is reduced by heating when the conductive adhesive is melted. Are fixed using the adhesive force of the pressure-sensitive adhesive sheet, and after the conductive adhesive is heated and melted, the pressure-sensitive adhesive sheet is used to reduce the adhesive force. Sticky A configuration that easily peeled solar cell module from the sheet.

  The manufacturing method of the solar cell module of the present invention uses an adhesive sheet whose adhesive strength is reduced by heating when melting the conductive adhesive, and arranges solar cells on the adhesive sheet before heating. Even if the solar cell is warped, the solar cell can be adhesively fixed on the pressure-sensitive adhesive sheet in a state in which the warp is eliminated. Due to the adhesive fixation, the solar battery cell is not displaced even if it receives vibration during conveyance to a heating furnace or the like. And when a conductive bonding agent is heated and melted in a heating furnace or the like, the adhesive force of the pressure-sensitive adhesive sheet can be reduced by the heating. Thereafter, when the molten conductive bonding agent is cooled and solidified, the cooling and solidified conductive bonding agent can connect adjacent solar cells with high accuracy, and form a high-quality solar cell module. it can. And the solar cell module can be easily peeled from the pressure-sensitive adhesive sheet having reduced adhesive strength. Furthermore, since the solar cell module is formed using an adhesive sheet as described above, the conventional large-scale assembly base is not required, so that the conveyance to a heating furnace or the like becomes lighter and easier. it can.

In particular, when the shear adhesive strength of the pressure-sensitive adhesive sheet is larger than 39.2 N / cm ² when the solar cells are arranged, and smaller than 5.9 N / cm ² after the conductive adhesive is heated and melted. In this case, the adhesive fixing of the solar battery cell and the peeling of the solar battery module are more appropriately performed.

  Further, when the pressure-sensitive adhesive sheet is a heat-peelable sheet composed of a base material sheet and an adhesive layer that is formed on at least one surface of the base material sheet and foams by heating when melting the conductive adhesive, The separation of the solar cell module becomes easier.

It is a front view which shows typically the solar cell module obtained by one Embodiment of the manufacturing method of the solar cell module of this invention. (A)-(d) is explanatory drawing which shows typically one Embodiment of the manufacturing method of the said solar cell module. It is a perspective view which shows a typical solar cell module typically. It is explanatory drawing which shows the manufacturing method of the conventional solar cell module typically.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a front view schematically showing a solar cell module obtained by an embodiment of a method for producing a solar cell module of the present invention. In the solar cell module A of this embodiment, a plurality of long plate-like solar cells 1 are connected in series in the width direction (X direction in FIG. 1). The connection is made by superimposing side edges along the longitudinal direction of adjacent solar cells 1 on the upper and lower sides via solder (conductive bonding agent) 2 that solidifies after melting.

  In this embodiment, the solar cell module A is manufactured by the following manufacturing method.

  First, as shown to Fig.2 (a), the adhesive sheet 3 from which adhesive force falls by the heating at the time of fuse | melting the unmelted solder 2a [refer FIG.2 (c)] is prepared. In this embodiment, the pressure-sensitive adhesive sheet 3 is composed of a single pressure-sensitive adhesive layer, and a foaming agent is blended with the pressure-sensitive adhesive. That is, the decrease in the adhesive force due to heating is due to the pressure-sensitive adhesive sheet 3 being foamed by the heating and the area of adhesion with the solar battery cell 1 being reduced.

Next, as shown in FIG. 2 (b), after one solar cell 1 is adhesively fixed on the adhesive sheet 3, one side (right side in the drawing) side edge of the surface of the solar cell 1. Then, the unmelted solder 2a is formed using a dispenser or the like. Then, the second solar cell 1 is adhesively fixed on the adhesive sheet 3 so that the back surface of the side edge of the second solar cell 1 overlaps with the unmelted solder 2a. To do. By repeating this, as shown in FIG. 2 (c), a plurality of solar cells 1 are stacked in a state where the side edges of adjacent solar cells 1 are vertically overlapped with unmelted solder 2a. Adhesive fixation is performed on the adhesive sheet 3. The shear adhesive strength of the pressure-sensitive adhesive sheet 3 at this time is 39 from the viewpoint of enabling the adhesive fixing with the warped solar cell 1 without warping, and from the viewpoint of preventing peeling by vibration or the like. It is preferable to set it to be larger than ² N / cm ² .

Next, as shown in FIG.2 (d), what adhered and fixed the some photovoltaic cell 1 on the said adhesive sheet 3 is conveyed to a heating furnace, and is heated with the heat source 10 of the heating furnace. By this heating, the unmelted solder 2a is melted, the pressure-sensitive adhesive sheet 3 is expanded and expanded, and the pressure-sensitive adhesive force of the foamed and expanded pressure-sensitive adhesive sheet 3A is reduced. Then, it takes out from a heating furnace, it cools, the molten solder is solidified, The solar cell module A (refer FIG. 1) to which the adjacent photovoltaic cell 1 was connected with the solidified solder 2 is formed. And the obtained solar cell module A is peeled from the foamed and expanded PSA sheet 3A. At this time, since the adhesive strength of the foamed and expanded adhesive sheet 3A is reduced, the solar cell module A can be easily peeled off. In this case, the shear adhesive strength of the foamed and expanded pressure-sensitive adhesive sheet 3A is preferably set to be smaller than 5.9 N / cm ² from the viewpoint of facilitating the peeling of the solar cell module A.

  Here, the pressure-sensitive adhesive sheet 3 that is used for the production method of the solar cell module A and whose adhesive strength is reduced by heating will be described in detail.

  As described above, the pressure-sensitive adhesive sheet 3 is obtained by blending a foaming agent with a pressure-sensitive adhesive in this embodiment.

  Examples of the pressure-sensitive adhesive include rubber-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, styrene / conjugated diene block copolymer-based pressure-sensitive adhesives, and silicone-based pressure-sensitive adhesives. In addition, you may mix | blend additives, such as a crosslinking agent, tackifier, a plasticizer, a filler, an anti-aging agent, as needed.

  Examples of the rubber-based pressure-sensitive adhesive include those using natural rubber or various synthetic rubbers as a base polymer. Examples of the acrylic pressure-sensitive adhesive include methyl group, ethyl group, propyl group, butyl group, 2-ethylhexyl group, isooctyl group, isononyl group, isodecyl group, dodecyl group, lauryl group, tridecyl group, pentadecyl group, hexadecyl group, Acrylic acid alkyl esters such as heptadecyl, octadecyl, nonadecyl, and eicosyl groups having an alkyl group with 20 or less carbon atoms such as acrylic acid and methacrylic acid, hydroxyethyl group, hydroxypropyl group, glycidyl group Esters such as acrylic acid and methacrylic acid having such functional group-containing groups, acrylic acid, methacrylic acid, itaconic acid, N-methylolacrylamide, acrylonitrile, methacrylonitrile, vinyl acetate, styrene, isoprene, butadiene, isobutylene, vinyl Having an acrylic polymer to the ether or the like as a component-based polymers.

  Examples of the foaming agent include decomposition-type inorganic foaming agents such as ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, ammonium nitrite, sodium borohydride, and azides, and organic foaming agents such as azo compounds. can give.

  Examples of the organic foaming agent such as the azo compound include fluorinated alkanes such as trichloromonofluoromethane and dichloromonofluoromethane, azobisisobutyronitrile, azodicarbonamide, and barium azodicarboxylate. Hydrazine compounds such as azo compounds, paratoluenesulfonyl hydrazide, diphenylsulfone-3,3′-disulfonyl hydrazide, 4,4′-oxybis (benzenesulfonyl hydrazide), allyl bis (sulfonyl hydrazide), ρ-toluylene sulfonyl Semicarbazide compounds such as semicarbazide and 4,4′-oxybis (benzenesulfonyl semicarbazide), triazole compounds such as 5-morpholyl-1,2,3,4-thiatriazole, N, N′-dinitrosopentamethene Examples thereof include N-nitroso compounds such as tylenetetramine and N, N′-dimethyl-N, N′-dinitrosotephthalamide, and other low-boiling compounds.

  Other foaming agents include, for example, thermal expansibility, such as isobutane, propane, and pentane, which are easily gasified and encapsulated in shell-forming materials by coacervation or interfacial polymerization. Fine particles. The average particle diameter of the thermally expandable fine particles is set within a range of 1 to 50 μm, for example. Examples of the shell-forming substance that forms the thermally expandable fine particles include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, and polysulfone.

  The blending ratio of the foaming agent is set in accordance with the degree to which the adhesive force is reduced. In this embodiment, for example, it is 10 to 95% by weight, preferably 20 to 80% by weight. In this embodiment, the expansion ratio of the pressure-sensitive adhesive sheet 3 is preferably set so that the expansion ratio is, for example, about 1.5 to 100 times.

  The pressure-sensitive adhesive sheet 3 can be formed by, for example, coating and forming a pressure-sensitive adhesive containing the foaming agent on the separator. The thickness of the adhesive sheet 3 is set in the range of 1 to 500 μm, for example.

  In the above-described embodiment, the pressure-sensitive adhesive sheet 3 is one in which the pressure-sensitive adhesive layer is foamed by heating and the pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer is reduced. You may use what falls.

  Moreover, in the said embodiment, although what consists of 1 layer of adhesive layers was used as the adhesive sheet 3, other may be sufficient, for example, the said base material and the said said formed on the single side | surface or both surfaces of this base material sheet You may use what consists of an adhesion layer. Examples of the base sheet include a resin sheet such as PET, a metal sheet such as stainless steel, and the like.

  Furthermore, when using the adhesive sheet which has the said base material sheet, what is induction-heated by a high frequency may be used as the base material sheet. When such a base material sheet is used, the base material sheet is induction-heated by high-frequency irradiation instead of heating by the heat source 10 (see FIG. 2D) in the heating furnace, and the heat is not melted. The solder 2a [see FIG. 2 (c)] can be melted and the adhesive strength of the adhesive layer can be reduced.

  Examples of the material for forming the base sheet to be induction-heated at high frequency include, for example, alloys mainly composed of a single component such as iron, nickel, copper, aluminum, titanium, zinc and tin, stainless steel such as SUS340, and permalloy. Various conductors and magnetic materials such as such alloys, metal oxides such as ferrite, and amorphous alloys such as iron and cobalt can be used.

  In addition, as the structure of the base sheet, for example, a single layer structure made of foil, a laminate structure in which a conductor layer or a magnetic layer made of foil or a vapor deposition film is formed on the base layer, and conductive powder or magnetic material on the base layer. Examples thereof include a containing structure in which powder is dispersed, and a superposed structure in which a base layer is coated with a layer containing conductive powder and magnetic powder. Two or more magnetic materials or conductors may be used in combination. In addition, examples of the shape of the base sheet include a net shape, a porous shape, and a non-woven fabric shape. And the thickness of a base material sheet is set in the range of 1-500 micrometers, for example.

  Examples of the base layer include fiber processed products such as paper, cloth, and nonwoven fabric, plastic or rubber-like polymer films or foamed films, plastic laminates thereof, and laminates of plastics. It is done.

  Next, examples will be described together with comparative examples. However, the present invention is not limited to the examples.

[Production of solar cells]
On one side of a stainless steel substrate (flexible conductive substrate) having a width of 10 mm, a length of 100 m, and a thickness of 50 μm, a 0.3 μm thick Cr layer (barrier layer) and a 0.3 μm thick Mo layer (first Electrode layer), a 2 μm thick CIGS layer (light absorption layer) made of chalcopyrite compound, a 75 nm thick ZnMgO layer (buffer layer), and a 0.5 μm thick ITO layer (first electrode layer). Lamination was sequentially performed to obtain a solar battery cell substrate.

  Next, a Ni layer having a thickness of 50 nm was formed by sputtering on the surface of a width portion of 1 mm from the edge of one side edge along the longitudinal direction of the solar cell substrate, and then a thickness of 50 nm was formed on the surface of the Ni layer. A Cu layer was formed by sputtering. Similarly, a Ni layer and a Cu layer were laminated on the back surface of the solar cell substrate.

  And the photovoltaic cell base | substrate with which the Ni layer and Cu layer were laminated | stacked was cut | disconnected in the width direction at intervals of 100 mm in length, and the photovoltaic cell of width 10mm x length 100mm was obtained.

[Example 1]
A heat release sheet (manufactured by Nitto Denko Corporation, heat release sheet: Riva Alpha No. 3195) provided with an adhesive layer that foamed by heating was prepared. And after sticking and fixing one solar cell on the surface of the heat release sheet, Sn-Bi solder was applied to the Cu layer on the surface of the solar cell in a width of 1 mm using a dispenser. . Next, the second solar cell was adhesively fixed on the heat release sheet so that the back surface of the side edge of the second solar cell overlapped with a width of 1 mm. This was repeated 11 times, and 11 solar cells were placed on the heat-peeled sheet with the side edges of adjacent solar cells stacked one above the other via unmelted Sn-Bi solder. An adhesive-fixed solar cell module substrate (100 mm × 101 mm) was obtained.

  And the thing of the state by which the solar cell module base | substrate was adhesive-fixed on the said heat peeling sheet was pinched | interposed with two glass plates, and it installed in the heating furnace in the state. Then, while making the inside of a heating furnace into nitrogen atmosphere and heating at 200 degreeC for 30 minute (s), while melting the unmelted Sn-Bi type | system | group solder, the adhesive force of the said heat peeling sheet was weakened. Then, it took out from the heating furnace and solidified the melted Sn—Bi-based solder to obtain a solar cell module to which adjacent solar cells were connected. And the obtained solar cell module was peeled from the said heat peeling sheet.

Moreover, the shear adhesive strength of the said heat peeling sheet was measured using the measuring device (Shimadzu Corporation autograph) before and after heating with a heating furnace. As a result, before heating 46N / cm ^2, after heating was 3N / cm ^2.

[Example 2]
In Example 1 above, the adhesive fixing of the solar cells was replaced with a heat-release sheet, and a heat-resistant sheet (Nitto Denko Corporation, heat-resistant double-sided adhesive tape No. 581). Other than that, it was the same as in Example 1 above. Further, the shear adhesive strength of the heat-resistant sheet, before heating 42N / cm ^2, after heating was 5.5 N / cm ^2.

[Comparative Example 1]
In the said Example 1, the fixation of the photovoltaic cell was changed into the heat peeling sheet, and the vacuum suction on the stage was utilized. Other than that, it was the same as in Example 1 above.

[Comparative Example 2]
In the said Example 1, fixing of the photovoltaic cell was replaced with the heat peeling sheet, and the conventional base for assembly (refer FIG. 4) in which many level | step differences were formed in the mounting surface of the photovoltaic cell was utilized. Other than that, it was the same as in Example 1 above.

[Comparative Example 3]
In the said Example 1, the solar cell module was obtained like Example 1 without utilizing the fixing means (heat peeling sheet) which fixes a photovoltaic cell.

〔Visual inspection〕
In the said Example 1, 2 and Comparative Examples 1-3, 100 solar cell modules were produced, respectively, and those external appearances were test | inspected. And what does not have abnormality, such as peeling of a photovoltaic cell, was made into the acceptable product, and the number of the acceptable products was shown in following Table 1.

  From the results of Table 1 above, it can be seen that 100% acceptable products could be produced in Examples 1 and 2 but not in Comparative Examples 1 to 3. The reason is presumed that in Comparative Examples 1 to 3, the solar cells are not fixed (shifted) at appropriate positions when the solar cells are connected.

  The manufacturing method of the solar cell module of this invention is applicable when producing a solar cell module in the state which connected the photovoltaic cell with high precision.

DESCRIPTION OF SYMBOLS 1 Solar cell 2a Unmelted solder 3 Adhesive sheet

Claims (3)

  The step of disposing a plurality of solar cells in a state where the side edge portions of adjacent solar cells are vertically overlapped with an unmelted conductive adhesive, and the conductive adhesive is heated and melted. And a step of connecting adjacent solar cells by cooling and solidification, and a method of manufacturing a solar cell module that obtains a solar cell module in which the plurality of solar cells are connected in series. The cell is placed on a pressure-sensitive adhesive sheet whose adhesive strength is reduced by heating when the conductive adhesive is melted. When the solar cells are placed, the solar cells are attached to the pressure-sensitive adhesive force of the pressure-sensitive adhesive sheet. After fixing the conductive bonding agent and heating and melting the conductive bonding agent, the solar cell module is easily peeled off from the pressure-sensitive adhesive sheet by using the pressure-sensitive adhesive sheet. Manufacturing method of solar cell modules. The shear adhesive strength of the pressure-sensitive adhesive sheet is larger than 39.2 N / cm ² when the solar battery cell is arranged, and smaller than 5.9 N / cm ² after the conductive adhesive is heated and melted. Of solar cell module.   The pressure-sensitive adhesive sheet is a heat-peelable sheet comprising a base material sheet and an adhesive layer formed on at least one surface of the base material sheet and foamed by heating when melting the conductive adhesive. The manufacturing method of the solar cell module of Claim 1 or 2 with which arrangement | positioning is made | formed on the said adhesion layer.

Images