JP2016036029A - Solar battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar battery module which is further increased in efficiency and decreased in its manufacturing steps.SOLUTION: A solar battery module comprises: a first solar battery C1 and a second solar battery C2, each including a semiconductor substrate 110 and a first electrode part C141 and a second electrode part C142 which are different from each other in polarity; interconnectors CW1, CW2 for electrically connecting the first solar battery C1 and the second solar battery C2; a conductive adhesive for electrically connecting the interconnectors CW1, CW2 to the relevant electrode parts of the first solar battery C1 and the second solar battery C2; and at least one insulative adhesive part AT for temporarily fixing the interconnectors CW1, CW2 to the relevant electrode parts. The at least one insulative adhesive part includes an adhesive for gluing the interconnectors CW1, CW2 to the relevant electrode parts.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a solar cell module including a plurality of solar cells.

  A general solar cell includes a substrate and an emitter that are semiconductors of different conductive types, such as p-type and n-type, and electrodes connected to the substrate and the emitter, respectively. At this time, a pn junction is formed at the interface between the substrate and the emitter.

  When light enters such a solar cell, electrons in the semiconductor become free electrons (hereinafter referred to as “electrons”) due to the photoelectric effect, and the electrons and holes are p−. Depending on the principle of n-junction, it moves in the direction of n-type semiconductor and p-type semiconductor, for example, in the direction of emitter and substrate, respectively. The moved electrons and holes are collected by the respective electrodes electrically connected to the substrate and the emitter.

  On the other hand, in recent years, in order to increase the efficiency of the solar cell, an interdigitated back contact solar cell in which an electrode is formed on the rear surface of the semiconductor substrate without forming an electrode on the light receiving surface of the semiconductor substrate has been developed. .

  A modular technology for connecting and electrically connecting a plurality of solar cells has also been developed. In the modular technology, a method for electrically connecting a plurality of solar cells to a wire in the form of a ribbon or a clip. and so on.

  An object of the present invention is to provide a solar cell module with further improved efficiency and reduced manufacturing steps.

  A solar cell module according to an embodiment of the present invention includes a first solar cell, a second solar cell, a first solar cell, and a second solar cell each including a semiconductor substrate and first and second electrode portions having different polarities. A plurality of interconnectors that electrically connect the batteries, a conductive adhesive that electrically connects the plurality of interconnectors to corresponding electrode portions of the first solar cell and the second solar cell, and a plurality of interconnectors, It includes at least one insulating adhesive part that is temporarily fixed to the electrode part, and the at least one insulating adhesive part includes an adhesive that adheres the interconnector to the electrode part.

  As an example, the insulating adhesive portion may be a pressure sensitive adhesive tape.

  Therefore, when an insulating adhesive portion provided with an adhesive is used, the interconnector can be bonded to the electrode portion without using a curing process.

  The insulative adhesive portion may be formed of a double-sided tape having adhesives on both sides or a single-sided tape having an adhesive on one surface.

  The insulating adhesive portion made of double-sided tape can be located between the interconnector and the semiconductor substrate, or between the interconnector and the electrode portion.

  The insulating adhesive portion made of single-sided tape can be positioned on the interconnector so that the adhesive faces the semiconductor substrate, and the insulating adhesive portion made of double-sided tape is also made of the insulating adhesive portion made of single-sided tape. Can be arranged in the same way.

  The first solar cell and the second solar cell can be positioned adjacent to each other in the first direction, and the plurality of interconnectors can extend in the first direction.

  In this case, the insulating adhesive portion may include a second tape located in one region of the semiconductor substrate and a second tape located in an opposite region opposite to the one region. The two tapes can extend in a second direction that intersects the first direction.

  Further, the insulating adhesive portion may include a third tape located between both side regions of the semiconductor substrate, in addition to the first and second adhesive portions described above.

  Here, the width of the insulating adhesive portion can be made larger than the width of the interconnector, and conversely, the width of the insulating adhesive portion can be the same as or smaller than the width of the interconnector.

  Then, at least one of the first tape and the second tape can be divided into a plurality along the second direction.

  The conductive adhesive may include a resin that is cured by thermal or light and a plurality of conductive particles dispersed within the resin.

  In this case, the interconnector can be made of conductive metal, or can be made of conductive metal and solder coated on the surface of the conductive metal. If the interconnector is made of conductive metal, the conductive metal is When the interconnector is provided with solder, the solder can be in direct contact with the adhesive of the insulating adhesive portion.

  In contrast, when the interconnector is made of conductive metal and solder coated on the surface of the conductive metal, the solder can be used as a conductive adhesive without using a separate conductive adhesive. In this case, the solder is preferably made of a low melting point solder having a melting temperature of 180 ° C. or lower.

  The first electrode part and the second electrode part may be located on the same surface of the semiconductor substrate.

  In this case, the first electrode unit includes a first finger electrode extended in the first direction, and the second electrode unit includes a second finger electrode extended in the first direction. The two-electrode portion may be formed in a non-busbar structure that does not include a busbar electrode that physically and electrically connects the finger electrodes.

  At this time, at least one of the first adhesive part and the second adhesive part may or may not overlap each other on the projection plane with at least one of the first finger electrode and the second finger electrode.

  In contrast, the first electrode part includes a first finger electrode extended in the second direction, and the second electrode includes a second finger electrode extended in the second direction. The second electrode part may be formed of a non-busbar structure that does not include a busbar electrode that physically and electrically connects the finger electrodes.

  At this time, among the plurality of interconnectors, the interconnector electrically connected to the first finger electrode of the first solar cell is formed by an insulating layer located at a portion intersecting with the second finger electrode of the first solar cell. The interconnector that may be insulated from the second finger electrode and electrically connected to the second finger electrode of the first solar cell has an insulating layer located at a portion intersecting the first finger electrode. The electrodes can be insulated from each other.

  On the other hand, as described above, when a solar cell having an electrode structure in which finger electrodes are formed in a direction intersecting with the extension direction of the interconnector is used, the first of the first solar cells is selected from the plurality of interconnectors. The interconnector that is electrically connected to the finger electrode can be adhered to the second finger electrode in a state of being insulated from each other by an insulating adhesive portion located at a portion intersecting the second finger electrode of the first solar cell. The interconnector that is electrically connected to the second finger electrode of the first solar cell is bonded to the first finger electrode in a state of being insulated from each other by an insulating adhesive portion located at a portion intersecting the first finger electrode. can do.

  Since the solar cell module having such a configuration includes an insulating adhesive portion that can temporarily fix the interconnector to the electrode portion at room temperature even if a separate curing step is not performed, the interconnector is A plurality of solar cells can be transferred to the stacking equipment while temporarily fixed to the electrode portion.

  Therefore, even if the tabbing process for electrically connecting the interconnector to the electrode unit is not performed, the interconnector and the electrode unit are aligned during the substrate transfer process to proceed with the laminating process. It is possible to effectively suppress the state from becoming defective.

  In addition, since the Tebin process in which the interconnector and the electrode part are electrically joined by the conductive adhesive is performed by the heat applied to the solar cell module during the lamination process, the substrate for proceeding with the lamination process There is no need to perform a separate tabine operation before the transfer process. Therefore, the manufacturing process of a solar cell module can be reduced.

  In addition, since the interconnector and the electrode part tebin process are performed during the lamination process, the board bowing phenomenon occurs compared to the case where another tebin process is performed before the lamination process. Can be suppressed.

  In addition, when an insulating adhesive portion is used, the interconnector can be locally fixed. Therefore, an adhesive is applied to one surface of the insulating substrate having a size larger than that of the semiconductor substrate, so that a plurality of interconnectors can be attached. Compared to fixing everything at once, the amount of material used can be reduced, so that the manufacturing cost can be reduced.

  Here, fixing the interconnector locally by using the insulating adhesive portion means that only a part of the interconnector is fixed on the projection plane by the insulating adhesive portion.

  In this way, the insulating adhesive portion can fix the interconnector in a local region, so that the overall area of the insulating adhesive portion is preferably as small as possible relative to the plane area of the substrate.

  As an example, the overall plane area of the insulative bonding portion is understood to be 0.5 times or less, preferably 0.2 times, more preferably 0.1 times or less the plane area of the substrate.

It is a figure for demonstrating 1st Embodiment of the solar cell module which concerns on this invention. It is sectional drawing of the part of "A" shown in FIG. It is sectional drawing of the part of "B" shown in FIG. It is a figure for demonstrating the deformation | transformation embodiment of FIG. FIG. 5 is a cross-sectional view of a portion “C” shown in FIG. 4. It is a figure for demonstrating an example of the back surface junction solar cell applicable to the solar cell module shown by FIG. 7 shows an example in which an insulating paste is applied to the rear surface of the back junction solar cell shown in FIG. 6. It is a figure for demonstrating 2nd Embodiment of the solar cell module which concerns on this invention. FIG. 9 illustrates a state in which an insulating adhesive portion is bonded to the rear surface of the rear surface bonded solar cell illustrated in FIG. 8. It is a figure for demonstrating 3rd Embodiment of the solar cell module which concerns on this invention. It is a figure which shows the deformation | transformation embodiment of FIG. It is sectional drawing of the part of "D" shown in FIG. It is a figure for demonstrating an example in which the number of the insulation adhesion parts was adjusted so that it may differ from FIG. It is a figure for demonstrating an example in which the insulating adhesion part was divided | segmented into multiple along the 2nd direction so that it may differ from FIG. It is a figure for demonstrating 4th Embodiment of the solar cell module which concerns on this invention.

  While the invention is susceptible to various modifications, and may have several embodiments, specific embodiments are illustrated in the drawings and will be described in detail in the detailed description. It should be understood that the present invention is not limited to a specific embodiment and includes all modifications, equivalents or alternatives included in the spirit and technical scope of the present invention.

  In describing the present invention, terms such as first and second may be used to describe various components, which may not be limited by the terms. The terms can only be used to distinguish one component from another.

  For example, the first component can be named as the second component without departing from the scope of the present invention, and the second component can be named as the first component as well.

  The term “and / or” can include any combination of a plurality of related description items or any of a plurality of related description items.

  Any component that is referred to as “connected” or “coupled” to another component may be directly connected to or otherwise coupled to the other component However, it can be understood that there may be other components in the middle.

  Conversely, when any component is referred to as being “directly connected” or “directly coupled” to another component, it is understood that there are no other components in between. Can do.

  The terms used in the present application are merely used to describe particular embodiments, and are not intended to limit the present invention. A singular expression may include a plurality of expressions unless the context clearly indicates otherwise.

  In this application, terms such as “comprising” or “having” are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described in the specification. It can be understood that it does not preliminarily exclude the presence or possibility of addition of one or more other features or numbers, steps, actions, components, parts, or combinations thereof.

  In the figure, the thickness is shown enlarged to clearly represent many layers and regions. When a part such as a layer, film, region, plate, etc. is said to be “on top” of another part, this includes not only the case of “on top” of the other part but also the case where there is another part in between. Conversely, when any part is said to be “directly above” another part, it means that there is no other part in the middle.

  Unless defined differently, all terms used herein, including technical or scientific terms, are generally understood by those of ordinary skill in the art to which this invention belongs. Can have the same meaning.

  Terms such as those defined in commonly used dictionaries may be construed as having a meaning consistent with the meaning possessed in the context of the related art and are ideal unless explicitly defined in this application. Or may not be interpreted as an overly formal meaning.

  Further, the following embodiments are provided for a more complete explanation to those having average knowledge in the industry, and the shapes and sizes of elements in the drawings are more clearly described. Can be exaggerated for simple explanation.

  Now, an embodiment of the present invention will be described with reference to FIGS. 1 to 3, 6 and 7.

  In the following embodiments, a description will be given of a back-junction solar cell in which the first electrode portion and the second electrode portion having different polarities are all located on the rear surface of the semiconductor substrate. However, the present invention relates to MWT (Metal Wrap Through). ) Can also be applied to solar cells with a structure, and can also be applied to normal single-sided or double-sided solar cells where the first and second electrode parts are located on different surfaces of the semiconductor substrate. The present invention can also be applied to solar cells having various other electrode structures.

  FIG. 1 is a diagram for explaining a first embodiment of a solar cell module according to the present invention, FIG. 2 is a cross-sectional view of a portion “A” shown in FIG. 1, and FIG. 2 is a cross-sectional view of a portion “B” shown in FIG.

  6 is a diagram for explaining an example of a back junction solar cell applicable to the solar cell module shown in FIG. 1, and FIG. 7 is a rear view of the back junction solar cell shown in FIG. Shows an example in which an insulating paste is applied.

  Further, FIG. 13 is a diagram for explaining an example in which the number of insulating adhesive portions is adjusted to be different from that in FIG. 1, and FIG. 14 is different from FIG. It is a figure for demonstrating an example divided | segmented into multiple along 2 directions.

First, as shown in FIG. 1, the solar cell module according to the first embodiment of the present invention includes a first back-junction solar cell (C1) and a second that are alternately positioned in the first direction (XX ^′ ). Rear junction solar cell (C2), interconnectors (CW1, CW2) for electrically connecting the first rear junction solar cell (C1) and the second rear junction solar cell (C2) adjacent to each other, and the first and second rear surfaces It includes an insulating adhesive portion (AT) located in a part of the rear surface of the junction solar cell (C1, C2).

  Here, each of the plurality of back junction solar cells includes a semiconductor substrate 110, a first electrode portion including a plurality of first finger electrodes (C141), and a second electrode portion including a plurality of second finger electrodes (C142). . The first electrode portion and the second electrode portion are each formed in a non-busbar structure that does not include a busbar electrode that physically and electrically connects the finger electrodes.

  The semiconductor substrate 110 may be formed to include crystalline silicon or amorphous silicon, and a pn junction is formed on the semiconductor substrate 110 so that electricity is generated from incident light. be able to.

  Further, the first finger electrode (C141) and the second finger electrode (C142) may be formed on the rear surface of the semiconductor substrate 110 so as to be separated from each other in the first direction (X-X '). Such a rear junction solar cell will be described more specifically in FIG. 6 below.

  The interconnectors (CW1, CW2) electrically connect a plurality of solar cells including the first, second, and rear junction solar cells (C1, C2) to each other, as shown in FIG. 2 and FIG. Conductive metal formed of a metal having excellent conductivity such as copper (Cu) or silver (Ag), for example, outer surface of conductive wire (cw) and conductive wire (cw) having a circular cross-sectional shape It can be done with solder (sd) coated on the surface or only with conductive metal as shown in FIG.

  Furthermore, in the figure, the case where the number of interconnectors (CW1, CW2) is 6 for each of CW1 and CW2 is shown as an example, but the number of each of CW1 and CW2 may be formed between 10 to 20 it can.

  And solder (sd) can be performed with the low melting-point solder which has a melting temperature of 180 degrees C or less, or can be performed with the high melting-point solder fuse | melted at the temperature beyond it.

  The conductive metal of the interconnector (CW1, CW2) may be formed in a rectangular or quadrangular cross-sectional shape like a normal ribbon, and there are various cross-sectional shapes besides the circular or quadrangular cross-sectional shape. Can be formed.

  The interconnector is fixed and electrically connected to the electrode by a conductive adhesive (CP).

  The conductive adhesive (CP) includes a resin (resin, CP1) that is cured by thermal or light and a plurality of conductive particles (CP2) dispersed in the resin (CP1). The paste can be formed by curing with heat or light.

  Resin (CP1) will not be specifically limited if it is the material which has adhesiveness by a hardening process. However, in order to increase the adhesion reliability, it is desirable to use a thermosetting resin that is cured at a temperature lower than the temperature of the laminating process (about 150 ° C.).

  As the thermosetting resin, at least one resin selected from epoxy resin, phenoxy resin, acryl resin, polyimide resin, and polycarbonate resin is used. be able to.

  Resin (CP1) can contain a well-known hardening | curing agent and hardening accelerator as arbitrary components other than a thermosetting resin.

  For example, the resin (CP1) is made of a silane coupling, a titanate coupling agent, an aluminate, in order to improve the adhesion between the electrode part and the interconnector. A modifying material such as a coupling agent can be contained, and a dispersing agent such as calcium phosphate or calcium carbonate can be contained in order to improve the dispersibility of the conductive particles (CP2). Further, the resin (CP1) can contain a rubber component such as acrylic rubber, silicone rubber, urethane, etc. in order to control the elastic modulus.

  And if the electroconductive particle (CP2) has electroconductivity, the material will not be specifically limited. The conductive particles (CP2) include copper (Cu), silver (Ag), gold (Au), iron (Fe), nickel (Ni), lead (Pb), zinc (Zn), cobalt (Co), titanium ( One or more kinds of metals selected from Ti) and magnesium (Mg) can be included as a main component, and the process can be performed using only metal particles or can be made of metal-coated resin particles.

  The conductive particles (CP2) can be formed in various shapes such as a flake shape, a burr shape, and a sphere shape.

  In terms of connection reliability after the resin (CP1) is cured, the amount of the conductive particles (CP2) dispersed in the resin (CP1) is 0 with respect to the total volume of the conductive adhesive (CP). It is desirable to be 5% by volume to 20% by volume.

  If the blending amount of the conductive particles (CP2) is less than 0.5% by volume, the physical contact with the electrode part decreases, so that the current flow may not be performed smoothly. When the content exceeds 20% by volume, the relative amount of the resin (CP2) may decrease, and the adhesive strength may decrease.

  As shown in FIG. 3, the conductive adhesive (CP) having such a structure may be locally applied only to a region where electrical connection with the electrode portion is required. The application position of the agent (CP) is not particularly limited.

That is, taking the embodiment shown in FIG. 1 as an example, an insulating layer (IL) is formed in a region overlapping with the interconnector on the projection plane along the length direction (XX ^′ ) of the interconnector. It can also apply | coat to the whole remaining area | region except the formed area | region.

  In such a solar cell module, the first, second and rear junction solar cells (C1, C2) are the first and second finger electrodes of the first, second and rear junction solar cells (C1, C2), respectively. They can be arranged in a direction that intersects the length direction of (C141, C142).

As an example, as shown in FIG. 1, the length direction of the first and second finger electrodes (C141, C142) of the respective rear junction solar cells (C1, C2) may be the second direction (YY ^′ ). The first, second and rear junction solar cells (C1, C2) can be arranged in the first direction (XX ^′ ).

Further, the length direction of the plurality of interconnectors (CW1, CW2) is the length of the first and second finger electrodes (C141, C142) of the first, second, and rear junction solar cells (C1, C2), respectively. It can be formed in a direction that intersects the direction (YY ^′ ). As an example, the length direction of the plurality of interconnectors (CW1, CW2) may be the first direction (XX ^′ ).

  Here, the plurality of interconnectors (CW1, CW2) are connected to the first finger electrode (C141) of the first rear surface junction solar cell (C1) and the first rear surface junction solar cell (C1). The second interconnector (CW2) connected to the second finger electrode (C142).

  In order to electrically connect the first, second and rear junction solar cells (C1, C2), the first interconnector (CW1) is a second finger electrode (C142) of the second rear junction solar cell (C2). The second interconnector (CW2) can be connected to the first finger electrode (C141) of the second rear surface junction solar cell (C2).

  Further, the first interconnector (CW1) is connected to the first solar cell (C1) by an insulating layer (IL) located at a portion intersecting the second finger electrode (C142) of the first rear junction solar cell (C1). The second solar cell (C1) is electrically insulated from the two-finger electrode (C142), and the second solar cell (C1) by an insulating layer (IL) positioned at a portion intersecting with the first finger electrode (C141) of the second rear junction solar cell (C2). The first finger electrode (C142) can be electrically insulated.

  In addition, the second interconnector (CW2) is connected to the first solar cell (C1) by an insulating layer (IL) located at a portion intersecting the first finger electrode (C141) of the first rear junction solar cell (C1). The second solar cell (C2) is electrically insulated from one electrode (C141) by an insulating layer (IL) positioned at a portion intersecting with the second finger electrode (C142) of the second rear junction solar cell (C2). It can be electrically insulated from the second finger electrode (C142).

  Here, the insulating layer (IL) may be formed of an insulating resin such as an epoxy resin that is cured by thermal or light.

  On the other hand, in the above, the case where the interconnectors (CW1, CW2) are directly connected to the electrodes of two solar cells adjacent to each other in order to connect a plurality of rear junction solar cells in series has been described as an example. Differently, the interconnectors (CW1, CW2) may be provided separately for each solar cell, and in such a case, another interconnector (not shown) may be provided.

  That is, the back surface of each rear junction solar cell is provided with each interconnector (CW1, CW2), and each interconnector (CW1, CW2) is connected to another interconnector, and a plurality of solar cells are electrically connected. It is also possible to be connected.

  Such an insulating adhesive portion (AT) is used for temporarily fixing a plurality of interconnectors (CW1, CW2) to the rear surface of the semiconductor substrate 110.

  Here, the insulating adhesive portion (AT) can be formed by using yeast or insulating adhesive tape to the insulating adhesive.

  More specifically, when yeast is used for insulating bonding at the insulating bonding portion (AT), as shown in FIG. 1, after arranging a plurality of interconnectors (CW1, CW2) on the rear surface of the semiconductor substrate 110, It is formed by drying in a state where the yeast-shaped insulating adhesive portion (AT) is applied to the insulating adhesive, or the yeast-shaped insulating adhesive portion (AT) is formed on the rear surface of the semiconductor substrate 110 to the insulating adhesive. After the plurality of interconnectors (CW1, CW2) are arranged in the applied state, they can be formed by drying.

  Further, when an insulating adhesive tape is used for the insulating adhesive portion (AT), the insulating adhesive tape can have a shape of an insulating adhesive tape. Below, the case where an insulating adhesive part (AT) is formed using an insulating adhesive tape is demonstrated as an example.

  When the insulating adhesive portion (AT) has the form of an insulating adhesive tape, the insulating adhesive tape temporarily fixes a plurality of interconnectors (CW1, CW2) to the rear surface of the semiconductor substrate 110, thereby forming a film (AT- 1) and a single-sided tape containing an adhesive (AT-2) located on one side of the film.

  Here, the adhesive (AT-2) contains an adhesive substance that can adhere the interconnector to the electrode part at room temperature, and the adhesive (AT-2) Adhesion of the interconnector to the electrode portion at room temperature (1 ° C. to 35 ° C.) preferably means that a separate step for curing the adhesive is not required.

  Therefore, when the insulating adhesive portion (AT) provided with the adhesive (AT-2) is used, the interconnector can be bonded to the electrode portion without using the curing step.

  As an example, the insulating adhesive portions (AT1, AT2) may be pressure sensitive adhesive tapes.

  As a more specific example, such an insulating adhesive portion (AT) may be melted or not melted by a laminating process involving heat treatment.

  When the insulating bonding part (AT) is formed of a material that melts during the laminating process, the film (AT-1) of the insulating bonding part (AT) may be formed including a polyolefin material, and may be bonded. The agent (AT-2) can be formed including at least one of acrylic, silicon, and epoxy.

  When the insulating adhesive part (AT) is formed of a material that does not melt during the laminating process, the insulating adhesive part (AT) film (AT-1) is PET (polyethylene terephthalate) or PI (polyimide). The adhesive (AT-2) may be formed to include at least one of acrylic, silicon, and epoxy.

  On the other hand, although not shown, the insulating adhesive part (AT) may further include a layer for blocking ultraviolet rays.

  The insulating adhesive portion (AT) having such a configuration can be positioned on the interconnector so that the adhesive (AT-2) faces the semiconductor substrate and temporarily fix the interconnector.

  Accordingly, the alignment state of the interconnector and the electrode part is not changed during the substrate transfer process for proceeding the laminating process without performing a tabbing process for electrically connecting the interconnector to the electrode part. It can suppress effectively that it becomes defective.

  As described above, the insulating adhesive portion (AT) is used to locally (temporarily) fix the interconnectors (CW1, CW2) before the laminating step or the tebin step.

  Here, fixing the interconnector locally by using the insulating adhesive portion means that only a part of the interconnector is fixed on the projection plane by the insulating adhesive portion.

  In this way, the insulating adhesive portion can fix the interconnector in a local region, so that the overall area of the insulating adhesive portion is preferably as small as possible relative to the plane area of the substrate.

  As an example, the overall plane area of the insulating adhesive portion may be 0.5 times or less, preferably 0.2 times or less, more preferably 0.1 times or less with respect to the plane area of the substrate.

  As described above, when the interconnector is locally fixed using the insulating adhesive portion, an adhesive is applied to one surface of the insulating substrate having a size larger than that of the semiconductor substrate, and a plurality of interconnectors are attached at a time. Compared to the conventional case of fixing, the amount of material used can be reduced, the occurrence of voids can be suppressed, and the thickness of the interconnector can be increased.

  Also, since the Tebin process in which the interconnector and the electrode part are electrically joined by the conductive adhesive due to the heat applied to the solar cell module during the lamination process will be performed, the progress of the lamination process There is no need to perform a separate tabine operation before the substrate transfer process. Therefore, the manufacturing process of a solar cell module can be reduced.

  In addition, since the interconnector and the electrode part tebin process are performed during the laminating process, the board bowing phenomenon occurs compared to the case where another tebin process is performed before the laminating process. It can be suppressed.

  According to the experiments of the present inventors, when the interconnectors (CW1, CW2) are (temporarily) fixed from the end portions of the interconnectors (CW1, CW2), the interconnectors are connected to the solar cells in the transfer process for proceeding with the laminating process. It was confirmed that it was able to be fixed well.

Therefore, in the present embodiment, the insulating bonding portion (AT) is a region on both sides of the semiconductor substrate 110 with a distance (D1) in the length direction of the interconnector, that is, the first direction (XX ^′ ). And the first tape (AT1) and the second tape (AT2) that are extended in the second direction (Y-Y ^' ).

  However, it is also possible to further arrange at least one tape in the space between the first tape (AT1) and the second tape (AT2).

  As an example, the insulating adhesive part (AT) may include a third tape (AT3) located between both side regions of the semiconductor substrate 110.

  As an example, as shown in FIG. 13 (a), the insulating adhesive portion (AT) according to the present invention includes, in addition to the first and second tapes (AT1, AT2) located on both sides of the semiconductor substrate 110, A third tape (AT3) located in the central region between the first and second tapes (AT1, AT2) is further included.

  However, unlike this, FIG. 1 shows an example in which the insulating adhesive portion includes the first and second tapes (AT1, AT2) disposed in both regions of each solar cell. As shown in (b), only one insulative adhesive part (AT) is arranged in the area inside each solar cell with the interconnectors (CW1, CW2) arranged on the rear surface of each solar cell. Then, the interconnectors (CW1, CW2) can be temporarily fixed to the rear surface of each solar cell.

  Here, the width of each of the insulating adhesive portions (AT1, AT2, AT3) is larger than the width of each of the interconnectors (CW1, CW2), thereby temporarily fixing the interconnectors (CW1, CW2) during the manufacturing process. Unlike the above, the width of each of the insulating adhesive portions (AT1, AT2, AT3) may be the same as or smaller than the width of the interconnector (CW1, CW2).

  Thereby, when manufacturing a solar cell module, an interconnector (CW1, CW2) can be more stably fixed before a lamination process, and the manufacturing process of a solar cell module can be made still easier.

Then, at least one of the first tape (AT1) and the second tape (AT2) can be divided into a plurality along the second direction (YY ^′ ).

As an example, as shown in FIG. 14, the first tape (AT1) is divided into a plurality of first tapes (AT1-a) and a first tape (b) which are divided into a plurality along the second direction (YY ^′ ). The second tape (AT2-a) may be formed to include (AT1-b), and the second tape (AT2) may be divided into a plurality of pieces along the second direction (YY ^' ). And the second b tape (AT2-b).

  Here, the first tape (AT1) and the second tape (AT2) are in various forms within the same number as the total number of the first interconnector (CW1) and the second interconnector (CW2), Each of the first tape (AT1) and the second tape (AT2) can be divided into the same number as the total number of the first interconnector (CW1) and the second interconnector (CW2). In each case, one insulating adhesive portion can temporarily fix one interconnector.

  The first tape (AT1) and the second tape (AT2) can overlap at least partially with the finger electrodes (C141, C142) on the projection surface, and may not overlap at all.

  Referring to FIG. 6, the back junction solar cell includes a semiconductor substrate 110, an antireflection film 130, an emitter 121, a back surface field (BSF, 172), a first finger electrode (C141), and a second finger. An electrode (C142) can be included.

  Here, although the antireflection film 130 and the rear surface electric field portion 172 may be omitted, the following description will be made by taking as an example that the antireflection film 130 and the rear surface electric field portion 172 are included as shown in FIG. .

  The semiconductor substrate 110 may be a semiconductor substrate 110 made of silicon of a first conductivity type, for example, n-type conductivity type. Such a semiconductor substrate 110 can be formed by doping a semiconductor wafer made of crystalline silicon material with a first conductivity type impurity.

  The emitters 121 are spaced apart from each other on the back surface of the semiconductor substrate 110 facing the front surface and extend in parallel to each other. There may be a plurality of such emitters 121, and the plurality of emitters 121 may include an impurity of a second conductivity type opposite to the conductivity type of the semiconductor substrate 110, for example, a p-type conductivity type.

  Thereby, a pn junction can be formed by the semiconductor substrate 110 and the emitter 121.

  A plurality of the rear surface electric field portions 172 may be located on the rear surface of the semiconductor substrate 110, are spaced apart in a direction parallel to the plurality of emitters 121, and extend in the same direction as the plurality of emitters 121.

  Therefore, as shown in FIG. 6, a plurality of emitters 121 and a plurality of rear surface electric field portions 172 can be alternately positioned on the rear surface of the semiconductor substrate 110.

  The plurality of back surface electric field portions 172 may be impurities containing, for example, an n ++ portion having impurities of the same conductivity type as the semiconductor substrate 110 in a higher concentration than the semiconductor substrate 110.

  The plurality of first finger electrodes (C141) are physically and electrically connected to the emitter 121, respectively, and can be formed on the rear surface of the semiconductor substrate 110 at the same position as the emitter 121 on the projection surface.

  The plurality of second finger electrodes (C142) are formed on the rear surface of the semiconductor substrate 110 at the same position as the plurality of rear surface electric field portions 172 on the projection plane, and each of the second finger electrodes (C142) is physically connected to the semiconductor substrate 110 via the rear surface electric field portion 172. And electrical connection.

  Here, the first finger electrode (C141) and the second finger electrode (C142) on the rear surface of the semiconductor substrate 110 may be physically insulated from each other physically and spatially.

Here, a plurality of first finger electrodes (C141) is, ^'can be extended long, the second direction ^(Y-Y second direction ^(Y-Y)' first direction intersecting the) (X-X ^′ ) Can be spaced apart from each other.

Then, a plurality of second finger electrodes (C 142) also the second direction ^{(Y-Y ')} in the long that can be extended, the second direction ^(Y-Y') a first direction that intersects the ^(X-X ') Can be arranged apart from each other.

Further, the plurality of first and second finger electrodes (C141, C142) can be separated from each other, and the first finger electrode (C141) and the second finger electrode (C142) are in the first direction (XX ^′ ). Can be arranged alternately.

  The back junction solar cell applied to the solar cell module according to the present invention is not necessarily limited to the structure shown in FIG. 6 and can be changed to various structures.

As an example, the first, respectively, second finger electrode (C141, C 142) is ^'not extend to the second direction ^(Y-Y second direction ^(Y-Y)') in spaced apart from the dots from one another It is also possible to arrange in the form.

And it is long in the 1st direction (XX ^' ) so that it may connect in common with all the several 1st finger electrodes (C141) at either end of the 2nd direction (YY ^' ) on the rear surface of the semiconductor substrate 110. An extended first bus bar electrode (not shown) may be further provided. Similarly, a plurality of second fingers may be formed on the rear surface of the semiconductor substrate 110 at the other end in the second direction (Y-Y ^' ). A second bus bar electrode (not shown) extended in the first direction (XX ^′ ) so as to be commonly connected to all the electrodes (C142) may be further provided.

  In the back junction solar cell of FIG. 6, in order to connect the interconnectors (CW1, CW2) only to the electrodes, an insulating paste (ILP) is applied as shown in FIG. Can do.

For example, in order to connect the first and second interconnectors (CW1, CW2) to the plurality of first finger electrodes (C141) and the plurality of second finger electrodes (C142) formed on the rear surface of the semiconductor substrate 110, insulation is performed. As shown in FIG. 7, the conductive paste (ILP) can be applied on the plurality of first and second finger electrodes (C141, C142) extending in the second direction (YY ^′ ).

  Then, as shown in FIG. 1, the first and second interconnectors (CW1, CW2) are aligned and arranged on the rear surface of the electrodes, and the first and second interconnectors are used by using the insulating adhesive portions (AT1, AT2). (2) The interconnector (CW1, CW2) is (temporarily) fixed to the electrode and then the lamination process is performed, or only a part of the region is heated locally to connect the interconnector (CW1, CW2) to the electrode. After performing the joining process, a laminating process is performed.

  Here, the partial region may be a remaining region excluding the position where the insulating adhesive portions (AT1, AT2) are arranged. As an example, the center of the substrate located between the insulating adhesive portions (AT1, AT2) Can be an area.

  In contrast, the partial region may be a region where the interconnector and the electrode overlap each other on the projection plane.

  As described above, when the Tebin process is performed by locally applying heat to only a part of the region, the conductive adhesive (CP) located in the region to which the heat has been applied is melted and cured. The electrodes are electrically joined.

  The solder (sd) of the interconnectors (CW1, CW2) located in the area where heat is applied is melted by the heat, but the solder of the interconnectors (CW1, CW2) located in the area where no heat is applied. (Sd) is not melted.

  Accordingly, in the region where heat is applied, the interconnectors (CW1, CW2) are fixed to the electrode by the conductive adhesive (CP) and the solder (sd) and are electrically connected to the electrode.

  Thus, the interconnectors (CW1, CW2) are fixed to the electrodes to be electrically connected by the conductive adhesive (CP) and the solder (sd), and insulated from the electrodes that should not be electrically connected. It is fixed with an adhesive paste (ILP).

  And even when the tabin work is carried out locally, the interconnector is physically fixed by the insulating adhesive, so that the movement of the interconnector is minimized and the board is bowed by the local tabine operation. The phenomenon is suppressed.

  When the interconnector is temporarily fixed using the insulating adhesive portions (AT1, AT2) and the interconnector is only made of the conductive metal (cw), the conductive metal is the adhesive (AT) of the insulating adhesive portion. -2), and when the interconnector includes solder (sd), the solder (sd) can directly contact the adhesive (AT-2) of the insulating adhesive portion.

  On the other hand, the solar cell module of the present embodiment is a state in which the interconnector is temporarily fixed to the electrode portion of the solar cell using the insulating adhesive portions (AT1, AT2), and without performing another tabine process, It is also possible to carry out the laminating process immediately.

  More specifically, the conductive adhesive (CP) is located in the region where the electrode and the interconnector overlap each other on the projection surface as shown in FIG. (CP) includes a resin (CP1) that is cured by thermal or light as described above and a plurality of conductive particles (CP2) dispersed in the resin. The thermosetting resin is cured at a temperature lower than the temperature (about 150 ° C. or outside) in the lamination process of the solar cell module.

  Therefore, since the conductive adhesive (CP) is cured during the laminating process without performing another tabine process, the interconnector is electrically connected to the electrode.

  When the conductive adhesive (CP) is not used, when the interconnector solder (sd) is formed of a low melting point solder melted at a temperature of about 180 ° C. or less, the laminating process proceeds as described above. Meanwhile, since the low melting point solder is melted and soldered, the interconnector is electrically connected to the electrode.

  Therefore, when manufacturing the solar cell module according to the embodiment of the present invention, the Tebin process can be performed separately, but in order to reduce the manufacturing process and improve the production efficiency, during the lamination process It is desirable to perform the Tebin process.

  And if the manufacturing method of a module is comprised so that a Tebin process may be performed during a lamination process, generally the curvature phenomenon of the solar cell which generate | occur | produces during a Tebin process will be suppressed.

  Hereinafter, a modified embodiment of FIGS. 1 to 3 will be described with reference to FIGS. 4 and 5. In the description of the present embodiment, the same reference numerals are given to the same components as those of the above-described embodiments of FIGS. 1 to 3, and detailed description thereof will be omitted.

  In the solar cell module of the present embodiment, the insulating adhesive portions (AT1, AT2) are different from the above-described embodiments of FIGS. 1 to 3 in that the adhesive (AT-) is formed on both sides of the film (AT-1). 2).

  Therefore, after attaching the insulating adhesive parts (AT1, AT2) to the rear surface of the semiconductor substrate, the interconnector may be temporarily fixed by arranging the interconnector on the electrode part. Unlike the third embodiment, the insulating adhesive portions (AT1, AT2) can be located between the interconnector and the semiconductor substrate.

  The second embodiment of the present invention will be described below. FIG. 8 is a view for explaining a solar cell module according to the second embodiment of the present invention. FIG. 9 shows an insulating adhesive portion on the rear surface of the rear junction solar cell shown in FIG. It shows a bonded state.

  As shown, in the solar cell module of the present embodiment, the insulating adhesive portion (AT) composed of a double-sided tape is located on the insulating layer (ILP) described in the embodiment of FIGS. A feature located in the region.

  A separate insulating adhesive portion is not located at the corner of the substrate.

  However, as in the embodiment of FIGS. 1 to 3, it is also possible to place an insulating adhesive portion at the corner of the substrate.

  In the solar cell module having such a configuration, the interconnector (CW1) electrically connected to the first finger electrode (C141) of the first solar cell (C1) is the second of the first solar cell (C1). The second finger electrode (C142) is adhered to the second finger electrode (C142) in a state of being electrically insulated from each other by an insulating adhesive portion (AT) located at a portion intersecting the finger electrode (C142), and the first solar cell (C1) The interconnector (CW2) that is electrically connected to the second finger electrode (C142) has the first finger electrode (C141) by the insulating adhesive portion (AT) located at a portion intersecting the first finger electrode (C141). ) And are electrically insulated from each other.

  Therefore, the electrical insulation can be achieved in a region where electrical insulation is necessary even though another insulation layer is not formed. Therefore, the insulation layer of the first embodiment described above can be removed. This can further reduce the manufacturing process and manufacturing cost.

  The solar cell modules arranged so that the arrangement direction of the solar cells and the length direction of the interconnectors (CW1, CW2) intersect with the length direction of the finger electrodes (C141, C142) have been described above.

  However, unlike this, the arrangement direction of the solar cells and the length direction of the interconnectors (CW1, CW2) are arranged or arranged in the same direction as the length direction of the finger electrodes (C141, C142). Is also possible.

  Such a case will be described with reference to FIG. FIG. 10 is a diagram for explaining a third embodiment of the solar cell module according to the present invention.

  In describing the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the embodiment of FIG. 10, the interconnectors (CW1, CW2) are displayed as lines for the sake of simplicity.

In the solar cell module according to the present embodiment, the arrangement direction of the solar cells (C1, C2) and the length direction of the interconnectors (CW1, CW2) are the same as the length direction of the finger electrodes (C141, C142), that is, , Formed in the first direction (XX ^′ ).

The first finger electrode (C141) and the second finger electrode (C142) are all extended in the first direction (XX ^′ ), and the interconnectors (CW1, CW2) are connected to the first rear junction solar cell (C1). The first finger electrode (C141) and the first finger electrode (C141) of the second rear junction solar cell (C2) are electrically connected to each other, or the second finger electrode (C1) of the first rear junction solar cell (C1) ( C142) and the second finger electrode (C142) of the second rear junction solar cell (C2) are electrically connected to each other.

Then, the first direction ^{(X-X ')} first tape (AT1) and the second tape that is long extended in the second direction ^(Y-Y which intersects ^the') (AT2), the interval in the first direction (D2 ) And spaced apart from each other on the rear surface of the semiconductor substrate 110.

At this time, the distance (D2) between the first tape (AT1) and the second tape (AT2) in the first direction (XX ^′ ) is the distance between the first finger electrode (C141) and the second finger electrode (C142). It may be formed larger than the length (L), and the insulating adhesive portions (AT1, AT2) may be either one-sided tape or double-sided tape.

Thus, the distance (D2) between the first tape (AT1) and the second tape (AT2) in the first direction (XX ^′ ) is the first finger electrode (C141) and the second finger electrode (C142). ) Larger than the length (L) of the first tape (AT1) and the second tape (AT2) on the projection plane with the first finger electrode (C141) and the second finger electrode (C142), respectively. Do not overlap each other. Therefore, the contact area between the finger electrodes (C141, C142) and the interconnector (CW1 or CW2) increases, and the charge collection efficiency of the solar cell module increases.

  FIG. 11 and FIG. 12 are diagrams showing a modified embodiment of FIG. 10, and unlike the above-described third embodiment of FIG. 10, between the first tape (AT1) and the second tape (AT2). The case where the distance (D2) is formed smaller than the length (L) of the first finger electrode (C141) and the second finger electrode (C142) is shown.

  In this case, at least one of the first tape (AT1) and the second tape (AT2) overlaps with at least one of the first finger electrode (C141) and the second finger electrode (C142) on the projection surface. can do.

  In the above description, the use of the insulating adhesive portion has been described as an example, but it is also possible to use an insulating adhesive other than the tape.

  FIG. 15 is a view for explaining a fourth embodiment of the solar cell module according to the present invention.

  In the first embodiment of the present invention, each of the interconnectors (CW1, CW2) has a length that is superimposed on all the two adjacent solar cells, and each of the interconnectors (CW1, CW2). However, the case where it was connected to the 1st finger electrode (C141) or the 2nd finger electrode (C142) of each solar cell was demonstrated as an example.

  To this end, in FIG. 1, the first interconnector (CW1) has a length that is superimposed on all of the first solar cell (C1) and the second solar cell (C2), and the first interconnector ( CW1) is electrically connected to the first finger electrode (C141) of the first solar cell (C1) by the conductive adhesive (CP), and is electrically connected to the second finger electrode (C142) of the second solar cell (C2). The case where it is electrically connected by the adhesive (CP) has been described as an example.

However, unlike this, as shown in FIG. 15, in the solar cell module according to the fourth embodiment of the present invention, each of the first and second interconnectors (CW1, CW2) is one solar cell. The first interconnector (CW1) is connected by a cell-to-cell connector (CC) that is only overlapped and connected via a conductive adhesive (CP) and is long between the solar cells in the second direction (Y-Y ^' ). ) And the second interconnector (CW2) can be connected in series with each other.

  More specifically, the first interconnector (CW1) is connected to the first finger electrode (C141) of each solar cell via a conductive adhesive (CP), and the second finger electrode (C142) of each solar cell. ) Can be insulated.

  Further, the second interconnector (CW2) is connected to the second finger electrode (C142) of each solar cell via a conductive adhesive (CP) and insulated from the first finger electrode (C141) of each solar cell. Can be done.

  Further, the connector (CC) between the cells includes the first interconnector (CW1) connected to the first finger electrode (C141) of the first solar cell (C1) and the second of the second solar cell (C2). The second interconnector (CW2) connected to the finger electrode (C142) is connected, and the first solar cell (C1) and the second solar cell (C2) can be connected in series with each other.

  Even in the solar cell module having such a structure, the insulating adhesive portions (AT1, AT2) are used to temporarily fix a plurality of interconnectors (CW1, CW2) connected to the solar cells to the rear surface of the semiconductor substrate 110. It is done.

At this time, as an example, as shown in FIG. 15, the insulating adhesive portions (AT 1, AT 2) are formed in the second direction ((YY) crossing the interconnectors (CW 1, CW 2) in the regions on both sides of each semiconductor substrate. ^′ ) Can be long.

Furthermore, as described with reference to FIGS. 13 and 14, only one such insulative bonding portion may be used for each solar cell, or may be divided and arranged separately in the second direction (YY ^′ ). It is also possible.

Claims (23)

A first solar cell and a second solar cell each comprising a first electrode part and a second electrode part having different polarities from the semiconductor substrate;
A plurality of interconnectors that electrically connect the first solar cell and the second solar cell;
A conductive adhesive that electrically connects the plurality of interconnectors to the electrode portions of the first solar cell and the second solar cell;
Including at least one insulating adhesive portion that temporarily fixes the plurality of interconnectors to the electrode portion;
The solar cell module, wherein the at least one insulating adhesive portion includes an adhesive that adheres the interconnector to the electrode portion.   2. The solar cell module according to claim 1, wherein the insulating adhesive portion is formed of a double-sided tape that includes the adhesive on both sides thereof and is located between the interconnector and the semiconductor substrate.   2. The solar cell according to claim 1, wherein the insulating adhesive portion is formed of a single-sided tape having an adhesive on one side and the adhesive is positioned on the interconnector so that the adhesive faces the semiconductor substrate. module.   2. The solar cell module according to claim 1, wherein the first solar cell and the second solar cell are positioned adjacent to each other along a first direction, and the plurality of interconnectors extend in the first direction. .   5. The solar cell according to claim 4, wherein the insulating adhesive portion includes a second tape located in one region of the semiconductor substrate and a second tape located in a region opposite to the one region. module.   The solar cell module according to claim 4, wherein the insulating adhesive portion includes a third tape located between both side regions of the semiconductor substrate.   The solar cell module according to claim 5, wherein the second tape and the second tape are formed of a tape extending in a second direction intersecting the first direction.   The solar cell module according to claim 5, wherein a width of the insulating adhesive portion is larger than a width of the interconnector.   The solar cell module according to claim 5, wherein a width of the insulating adhesive portion is the same as or smaller than a width of the interconnector.   The solar cell module according to claim 7, wherein at least one of the second tape and the second tape is divided into a plurality along the second direction.   The conductive adhesive according to claim 4, wherein the conductive adhesive includes a resin that is cured by thermal or light and a plurality of conductive particles dispersed in the resin. Solar cell module.   The solar cell module according to claim 11, wherein the interconnector is made of a conductive metal, and the conductive metal is in direct contact with an adhesive of the insulating adhesive portion.   The solar cell module according to claim 11, wherein the interconnector is made of a conductive metal and solder coated on the surface of the conductive metal, and the solder is in direct contact with the adhesive of the insulating adhesive portion.   The solar cell module according to claim 4, wherein the interconnector includes a conductive metal and a solder coated on a surface of the conductive metal, and the solder acts as the conductive adhesive.   The solar cell module according to claim 14, wherein the solder is a low melting point solder having a melting temperature of 180 ° C. or less.   The solar cell module according to claim 7, wherein the first electrode portion and the second electrode portion are located on the same surface of the semiconductor substrate.   The first electrode part includes a first finger electrode extended in the first direction, the second electrode part includes a second finger electrode extended in the first direction, and the first electrode The solar cell according to claim 16, wherein the part and the second electrode part are formed in a non-busbar structure that does not include a busbar electrode that physically and electrically connects the finger electrode. Battery module.   The solar cell of claim 17, wherein at least one of the second tape and the second tape overlaps at least one of the first finger electrode and the second finger electrode on a projection plane. module.   The solar cell module according to claim 17, wherein each of the second tape and the second tape does not overlap with the first finger electrode and the second finger electrode on a projection plane.   The first electrode part includes a first finger electrode extended in the second direction, the second electrode includes a second finger electrode extended in the second direction, and the first electrode part. The solar cell of claim 16, wherein the second electrode part has a non-busbar structure that does not include a busbar electrode that physically and electrically connects the finger electrodes. module. Among the plurality of interconnectors, an interconnector electrically connected to the first finger electrode of the first solar cell is an insulation located at a portion intersecting the second finger electrode of the first solar cell. Insulated from the second finger electrode by a layer,
Among the plurality of interconnectors, an interconnector electrically connected to the second finger electrode of the first solar cell is formed by an insulating layer located at a portion intersecting the first finger electrode. The solar cell module according to claim 20, wherein the solar cell module is insulated from the electrode.   The first electrode part includes a first finger electrode extended in a second direction intersecting the first direction, and the second electrode includes a second finger electrode extended in the second direction. The first electrode part and the second electrode part are formed in a non-busbar structure that does not include a busbar electrode that physically and electrically connects the finger electrodes. 2. The solar cell module according to 2. Among the plurality of interconnectors, the interconnector electrically connected to the first finger electrode of the first solar cell is located at a portion intersecting the second finger electrode of the first solar cell, Bonded in a state of being insulated from the second finger electrode by the insulating adhesive portion,
Of the plurality of interconnectors, an interconnector electrically connected to the second finger electrode of the first solar cell is located at a portion intersecting with the first finger electrode, by the insulating adhesive portion The solar cell module according to claim 22, wherein the solar cell module is bonded to the first finger electrode while being insulated from each other.

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