JP2015035436A - Solar cell module and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology which improves the reliability of a solar cell module.SOLUTION: A solar cell module 10 includes: a translucent member 12 disposed at the light receiving side; a rear surface glass plate 14 which is provided facing the translucent member; a photovoltaic device 16 provided between the translucent member 12 and the rear surface glass plate 14; and metal terminals 18, each of which is provided on a surface of the rear surface glass plate 14 and has a conductive path 18a for outputting electric power generated by the photovoltaic device 16 to the exterior. Through holes 20 are formed at the rear surface glass plate 14. Each metal terminal 18 is disposed so as to cover the through hole 20 and is fused to the rear surface glass plate 14 in at least a part of an area around the through hole 20.

Description

  The present invention relates to a solar cell module and a manufacturing method thereof.

  2. Description of the Related Art Conventionally, so-called solar cells have been vigorously developed in various fields as photoelectric conversion devices that convert light energy into electrical energy. Solar cells are expected to be a new energy source because they can directly convert light from the sun, a clean and inexhaustible energy source, into electricity.

  For example, in a solar cell panel, a transparent glass substrate, a filling adhesive, a photoelectric conversion panel, a filling adhesive, and a back surface protection cover material are sequentially stacked and integrated into a laminated configuration, and then the peripheral edge is sealed with a sealing material. Obtained. Here, in order to take out the electric power generated in the photoelectric conversion panel, the two lead wires connected to the photoelectric conversion panel penetrate the filling adhesive and the back surface protection cover material, and are provided outside the back surface protection cover material. In a box. Therefore, the back protective cover material is provided with a terminal port for penetrating the two lead wires. For the purpose of waterproofing, the terminal port is sealed with a filling adhesive such as silicone resin. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 9-279789

  By the way, in order to spread solar cells, it is necessary to reduce the power generation cost, and in order to achieve this, it is effective to extend the lifetime of the photoelectric conversion device. The main factor that hinders the longevity is the ingress of moisture into the photoelectric conversion panel. On the other hand, in order to prevent moisture from entering, as described above, the peripheral edge is sealed with a sealing material, or the terminal port is sealed with a filling adhesive.

  However, the sealing material and the filling adhesive deteriorate due to long-term use, and moisture easily enters. In particular, since the terminal port is provided close to the photoelectric conversion panel, the probability of failure of the photoelectric conversion panel increases when moisture enters from the terminal port. Although the above-mentioned filling adhesive is considered to be waterproof, there is room for further improvement from the viewpoint of moisture resistance.

  This invention is made | formed in view of such a condition, The objective is to provide the technique which improves the reliability of a solar cell module.

  In order to solve the above-described problems, a solar cell module according to an aspect of the present invention includes a translucent member disposed on the light receiving side, a back glass plate provided to face the translucent member, and a translucent member. A photovoltaic device provided between the conductive member and the back glass plate, and a conductive path provided on the surface of the back glass plate for outputting the electric power generated in the photovoltaic device to the outside. A terminal. The back glass plate has a through hole formed therein, and the terminal is disposed so as to cover the through hole, and at least a part of the periphery of the through hole is melt bonded to the back glass plate.

  Another aspect of the present invention is a method for manufacturing a solar cell module. In this method, a step of preparing a translucent member provided with a photovoltaic device, and an electric power generated in the photovoltaic device on the surface of a back glass plate in which a through hole is formed are externally provided. A step of arranging a terminal having a conductive path to be output so as to cover the through hole, and a laser beam having a pulse width of 1 nanosecond or less at the opposite portion between the back glass plate and the terminal around the through hole. A step of irradiating, and a step of making the translucent member and the back glass plate face each other and joining the peripheral portion.

  According to the present invention, the reliability of the solar cell module can be improved.

It is the top view which looked at the solar cell module which concerns on 1st Embodiment from the light-receiving surface side. It is AA sectional drawing of the terminal box vicinity shown in FIG. It is the front view which looked at the inside of the terminal box shown in FIG. 1 from the back surface side. FIG. 4A to FIG. 4C are diagrams for explaining a method for manufacturing a solar cell module. It is an enlarged view of the junction part vicinity of the metal terminal and back glass plate which concern on 2nd Embodiment. It is an enlarged view of the junction part vicinity of the metal terminal and back glass plate which concern on 3rd Embodiment. It is a figure which shows the modification of the connection mechanism of a metal terminal and a cable. It is a figure which shows the modification of the fusion | melting joining of a translucent member and a back surface glass plate. It is a figure which shows the modification of the fusion | melting joining of a translucent member and a back surface glass plate.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate.

  The scales and shapes of each layer and each part shown in the following drawings are set for convenience of explanation, and are not limitedly interpreted unless otherwise specified.

(First embodiment)
FIG. 1 is a plan view of the solar cell module according to the first embodiment viewed from the light receiving surface side. 2 is a cross-sectional view taken along the line AA in the vicinity of the terminal box shown in FIG. FIG. 3 is a front view of the inside of the terminal box shown in FIG. 1 viewed from the back side.

  The solar cell module 10 includes a translucent member 12 disposed on the light receiving side, a back glass plate 14 provided so as to face the translucent member 12, and the translucent member 12 and the back glass plate 14. And a photovoltaic device 16 provided therebetween.

  As the translucent member 12, for example, a glass plate having a 1 m square and a plate thickness of 4 mm is applied. However, the present invention is not limited to this, and any material that is suitable for forming the photovoltaic device 16 and that can mechanically support the solar cell module 10 may be used. Incidence of light to the solar cell module 10 is basically performed from the translucent member 12 side.

A photovoltaic device 16 is formed on the translucent member 12. The photovoltaic device 16 is formed by laminating a transparent electrode, a photoelectric conversion unit, a back electrode, and the like. The transparent electrode, for example, tin oxide (SnO ₂ ), zinc oxide (ZnO), indium tin oxide (ITO), etc. is doped with tin (Sn), antimony (Sb), fluorine (F), aluminum (Al), etc. Among the transparent conductive oxides (TCO), a film in which at least one kind or a plurality of kinds is combined can be used.

Examples of the photoelectric conversion unit include an amorphous silicon photoelectric conversion unit (a-Si unit) and a microcrystalline silicon photoelectric conversion unit (μc-Si unit). The photoelectric conversion unit may have a structure in which a plurality of photoelectric conversion units are stacked such as a tandem type or a triple type. The back electrode can be a transparent conductive oxide (TCO), a reflective metal, or a laminated structure thereof. As the transparent conductive oxide (TCO), tin oxide (SnO ₂ ), zinc oxide (ZnO), indium tin oxide (ITO) or the like is used, and as the reflective metal, silver (Ag), aluminum (Al ) Or the like is used.

  The back glass plate 14 is provided so as to cover the photovoltaic device 16 formed on the translucent member 12. The back glass plate 14 has, for example, substantially the same size as the translucent member 12, and a glass plate having a thickness of 3.2 mm is applied. However, it is not limited to this.

  The translucent member 12 and the back glass plate 14 are melt-bonded in the bonding region R1 of the outer peripheral edge region. The joining region R1 is provided in the peripheral portion R2 where the photovoltaic device 16 is not formed in the translucent member 12. For example, the peripheral portion R2 (region not hatched in FIG. 1) can be provided by removing the photovoltaic device 16 once formed on the translucent member 12 with a laser or the like. In order to melt and bond the translucent member 12 and the back glass plate 14, as shown in FIG. 2, at least one peripheral portion of the translucent member 12 and the back glass plate 14 may be bent. Is preferred.

  As shown in FIG. 2, the solar cell module 10 is provided on the front surface 14 a of the back glass plate 14, and has a metal terminal 18 having a conductive path 18 a that outputs power generated in the photovoltaic device 16 to the outside. It has. Further, the back glass plate 14 has two through holes 20 having a diameter of 6 mm formed at the center, and the metal terminals 18 are arranged so as to cover the through holes 20, and the periphery of the through holes 20 (see FIG. 3). At least a part of the hatching region R3) shown is melt bonded to the back glass plate 14.

  Therefore, in the solar cell module 10, the metal terminal 18 is melt-bonded and at least melt-bonded to the back glass plate 14 in at least a part of the periphery of the through-hole 20 in a state of covering the through-hole 20 of the back glass plate 14. Highly airtight against the ingress of moisture from the outside is realized in the part. Therefore, external moisture passes between the metal terminal 18 and the back glass plate 14 and is prevented from entering the inside of the solar cell module 10 through the through hole 20, and long-term reliability of the solar cell module 10. Can be improved.

  Here, “melt-bonding” can be understood as, for example, a state in which the metal terminals 18 and the back glass plate 14 are partly melted and joined together. More preferably, at the interface between the metal terminal 18 and the back glass plate 14, the material of the metal terminal 18 and the glass of the back glass plate 14 may be melted and mixed with each other.

  Next, an extraction path for the electric power generated by the photovoltaic device 16 will be described. As shown in FIGS. 1 and 2, a first current collecting wiring 22 and a second current collecting wiring 24 are formed in order to take out the electric power generated by the photovoltaic device 16. The first current collecting wiring 22 is a wiring for collecting current from the photovoltaic devices 16 divided in parallel, and the second current collecting wiring 24 is connected from the first current collecting wiring 22 to the terminal box 26. Wiring to do.

  The first current collector wiring 22 extends on the back electrode of the photovoltaic device 16. The first current collector wiring 22 is formed to connect the positive electrodes and the negative electrodes of the photoelectric conversion layers divided in parallel near the end of the solar cell module 10. Therefore, the 1st current collection wiring 22 is extended along the direction orthogonal to the parallel division direction of a photoelectric conversion layer. In the first embodiment, as shown in FIG. 1, the first current collector wiring 22 extends along the vertical direction on the left and right edges. As a result, the positive electrodes and the negative electrodes of the photovoltaic devices 16 connected in series are connected in parallel.

  In addition, an insulating coating material 28 is disposed to form electrical insulation between the second current collector wiring 24 and the back electrode of the photovoltaic device 16. As shown in FIG. 1 and FIG. 2, the insulating coating material 28 extends from the vicinity of the first current collector wiring 22 provided along the left and right edges of the solar cell module 10 to the vicinity of the arrangement position of the terminal box 26 in the central portion. , Extending on the back electrode of the photovoltaic device 16. The insulating coating material 28 is preferably made of, for example, polyester (PE), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, polyvinyl fluoride, or the like. Moreover, it is preferable to use the insulating coating material 28 in which an adhesive is applied to the back surface in a sealing manner.

  As shown in FIGS. 1 and 2, the second current collecting wiring 24 is extended from the left and right first current collecting wirings 22 along the insulating coating material 28 toward the center of the solar cell module 10. Yes. The insulation coating material 28 is sandwiched between the second current collecting wiring 24 and the back electrode of the photovoltaic device 16, so that electrical insulation between the second current collecting wiring 24 and the back electrode is maintained. On the other hand, one end of the second current collecting wiring 24 extends to the first current collecting wiring 22 and is electrically connected to the first current collecting wiring 22. For example, the second current collecting wiring 24 is preferably electrically connected to the first current collecting wiring 22 by ultrasonic soldering or the like. The other end of the 2nd current collection wiring 24 is electrically connected with the metal terminal 18 in the terminal box 26 via the spring which is the electroconductive elastic member mentioned later.

  A region where the translucent member 12 and the back glass plate 14 face each other is filled with a filler 30. As the filler 30, in addition to butyl rubber and ethylene vinyl acetate (EVA), materials used for coking such as silicone, filled resin materials such as polyvinyl butyral (PVB), ethylene resins such as ethylene ethyl acrylate copolymer (EEA), urethane, Acrylic or epoxy resin may be used.

<Melting method>
Next, a method for fusion bonding the translucent member 12 and the back glass plate 14 and the back glass plate 14 and the metal terminal 18 will be described.

  In the fusion bonding of the translucent member 12 and the back glass plate 14, as shown in FIG. 2, at least one peripheral portion of the translucent member 12 and the back glass plate 14 is bent to transmit the translucent member 12. And the rear surface glass plate 14 are in a state of being in close contact with each other. Then, a laser beam 34 is irradiated from the laser device 32 while focusing on the contact surface of the peripheral portion R2 that is in close contact, and scanning is performed along the outer peripheral four sides of the translucent member 12 and the back glass plate 14.

  The laser beam 34 is preferably a femtosecond laser beam. That is, the laser beam 34 preferably has a pulse width of 1 nanosecond or less. The laser beam 34 preferably has a wavelength at which absorption occurs in at least one of the translucent member 12 and the back glass plate 14. For example, it is preferable that the laser beam 34 has a wavelength of 800 nm. Furthermore, it is preferable that the laser beam 34 is irradiated at an energy density and a scanning speed sufficient to melt the translucent member 12 and the back glass plate 14. For example, the laser beam 34 is preferably irradiated with a pulse energy of a wavelength of 800 nm, a pulse width of 150 fs, an oscillation repetition rate of 1 kHz, and 5 microjoules (μJ) per pulse. The laser beam 34 is preferably scanned at a scanning speed of 60 mm / min. Further, the laser beam 34 may be irradiated from either the translucent member 12 side or the back glass plate 14 side.

  By the same method, the metal terminal 18 is melt-bonded to the back glass plate 14 in at least a part of the periphery of the through hole 20 (hatching region R3 shown in FIG. 3).

  The metal terminal 18 may be melt bonded to the back glass plate 14 over the entire circumference around the through hole 20. Accordingly, it is further suppressed that external moisture passes between the metal terminal 18 and the back glass plate 14 and enters the solar cell module 10 through the through hole 20.

<Metal terminal>
The metal terminal 18 has a cylindrical shape with a diameter of 30 mm and a thickness of 5 mm, and is made of copper. The metal terminal 18 is a metal whose surface is plated with a low resistivity material such as aluminum, gold or silver, Kovar (an alloy in which nickel and cobalt are mixed with iron), or at least a part of the metal terminal 18, or Other alloys may be used. Thereby, the electric power generated by the photovoltaic device 16 can be output to the outside through the metal terminal 18.

  The metal terminal 18 has a large-diameter cylindrical portion that faces the back glass plate 14 and a small-diameter cylindrical portion that protrudes from the center of one end face of the large-diameter cylindrical portion. The small-diameter columnar portion is positioned in the through hole 20 to position the metal terminal 18 with respect to the rear glass plate 14. Further, as shown in FIG. 2, a cable 36 is connected to the other end face of the large-diameter column by solder or the like.

<Method for manufacturing solar cell module>
FIG. 4A to FIG. 4C are diagrams for explaining a method for manufacturing a solar cell module. As shown in FIG. 4A, the metal terminal 18 to which the cable 36 is connected is arranged on the front surface 14 a of the back glass plate 14 in which the through hole 20 is formed so as to cover the through hole 20. And in the circumference | surroundings of the through-hole 20, the pulse width is 1 nanosecond or less from the opposite side to the side by which the metal terminal 18 of the back surface glass plate 14 is provided in the opposing part of the back surface glass plate 14 and the metal terminal 18. A laser beam 34 is irradiated using a laser device 32. Thereby, the metal terminal 18 and the back surface glass plate 14 are melt-bonded.

  In parallel with this, as shown in FIG. 4B, a translucent member 12 provided with the photovoltaic device 16 is prepared. In that case, the 1st current collection wiring 22, the 2nd current collection wiring 24, insulating covering material 28, filler 30 (not shown in Drawing 4 (b)) etc. are arranged suitably. Then, the back glass plate 14 on which the metal terminals 18 are melt-bonded and the translucent member 12 provided with the photovoltaic device 16 are opposed to each other and overlapped with each other in a predetermined positional relationship.

  At this time, a spring 38 as a conductive elastic member that conducts the metal terminal 18 and the photovoltaic device 16 is arranged in a state of being biased inside the through hole 20 (see FIG. 4C). One end of the biased spring 38 contacts the metal terminal 18 inside the through hole 20, and the other end contacts the second current collector wiring 24. That is, the second current collection wiring 24 and the cable 36 are electrically connected to each other via the spring 38 and the metal terminal 18. As a result, the solar cell module 10 is deformed by external force or heat, or the joining position of the metal terminal 18 is shifted, so that the positional relationship between the metal terminal 18 and the photovoltaic device 16 or each wiring changes. However, high connection reliability is realized.

  The surface of the spring 38 is covered with a material having a higher conductivity than the core material of the spring 38. Examples of the material having high conductivity include gold (Au), silver (Ag), and copper (Cu). Thereby, both moderate elasticity and moderate conductivity in the spring 38 can be achieved. The entire spring 38 may be made of a highly conductive material such as gold (Au), silver (Ag), or copper (Cu).

  After that, as shown in FIG. 4C, the translucent member 12 and the back glass plate 14 are opposed to each other, and the peripheral portion is melt-bonded by the laser beam 34 to complete the completely sealed solar cell module 10. To do.

  With such a method, by using a laser beam having a pulse width of 1 nanosecond or less, an airtight property can be obtained without filling a sealing member or an adhesive between the metal terminal 18 and the back glass plate 14. High solar cell modules can be continuously produced.

(Second Embodiment)
FIG. 5 is an enlarged view of the vicinity of the joint between the metal terminal and the back glass plate according to the second embodiment. The metal terminal 40 according to the second embodiment has a glass portion 40a in which glass frit is baked. The glass part 40 a is a cylindrical part fired around the small-diameter columnar part 40 b of the metal terminal 40. Here, the glass frit refers to, for example, glass fragments (flakes) or powder produced by melting a glass raw material at a high temperature and quenching.

  The glass part 40a is formed by applying a glass frit to the metal part of the metal terminal 40 using a dispenser and then baking at 200 ° C. for about 20 minutes.

  And the metal terminal 40 is fusion-bonded with the back surface glass plate 14 through the glass part 40a. As in the first embodiment, the fusion bonding is performed by a laser beam 34 emitted from the laser device 32 from the side opposite to the side where the metal terminals 40 of the back glass plate 14 are provided. Thus, in 2nd Embodiment, since the junction part of the metal terminal 40 and the back surface glass plate 14 is glass, stronger and highly fusion-bondable melt | fusion joining is attained.

(Third embodiment)
FIG. 6 is an enlarged view of the vicinity of the joint between the metal terminal and the back glass plate according to the third embodiment. First, the metal terminal 42 according to the third embodiment is brazed and welded to the intermediate glass 44 in which the through-hole 43 is formed, using a braze 46. The metal terminal 42 is preferably, for example, Kovar. The intermediate glass 44 is preferably a borosilicate glass that is easy to braze. Note that TIG (Tungsten Inert Gas) welding may be used instead of brazing.

  The metal terminal 42 is melt-bonded to the back glass plate 14 via the intermediate glass 44. The fusion bonding is performed by a laser beam 34 emitted from the laser device 32 as in the first embodiment. Thus, in 3rd Embodiment, since the junction part of the intermediate | middle glass 44 and the back surface glass plate 14 to which the metal terminal 40 is being fixed is glass, more firm and highly-sealing fusion joining is possible. Become.

  As described above, the present invention has been described with reference to each of the above-described embodiments, but the present invention is not limited to each of the above-described embodiments, and the configuration of the embodiments is appropriately combined or replaced. Are also included in the present invention. Further, it is possible to appropriately change the combination and processing order in each embodiment based on the knowledge of those skilled in the art and to add various modifications such as various design changes to each embodiment. Embodiments to which is added can also be included in the scope of the present invention.

  In each above-mentioned embodiment, although the metal terminal and the cable were joined by solder, you may connect via another member so that a metal terminal and a cable may be attached or detached. FIG. 7 is a diagram illustrating a modification of the connection mechanism between the metal terminal and the cable.

  The metal terminal 48 that is melt-bonded to the back glass plate 14 is connected to the cable 36 via the connection member 50. The connection member 50 includes a crimp terminal 52 that is crimped to one end of the cable 36, and a screw 54 that fixes the crimp terminal 52 to the metal terminal 48. Thereby, the metal terminal 48 and the cable 36 are detachably connected, and the cable 36 can be easily replaced.

  Moreover, in each above-mentioned embodiment, the peripheral part of the translucent member 12 and the back surface glass plate 14 is melt-bonded directly. However, there are cases where the photovoltaic device 16 and the wiring, etc., disposed inside the solar cell module are thick and it is difficult to bring the translucent member 12 and the back glass plate 14 into close contact with each other at the periphery. FIG. 8 and FIG. 9 are diagrams showing modifications of the fusion bonding between the translucent member 12 and the back glass plate 14.

  When the gap between the peripheral portions of the translucent member 12 and the back glass plate 14 becomes large, a spacer 56 is formed in the gap as shown in the cross-sectional view of FIG. The translucent member 12 and the back glass plate 14 may be melt-bonded by melting.

As the spacer 56, it is preferable to apply a material containing an element capable of melt-bonding the translucent member 12 and the back glass plate 14, such as Si, SiO, SiO ₂ , or SiO _X. For example, the frame-shaped spacer 56 may be formed by applying the above-described glass frit to the outer peripheral portion of the back glass plate 14 by screen printing and baking.

  Further, the laser beam 34 can be irradiated from either the translucent member 12 side or the back glass plate 14 side. Therefore, when the photovoltaic device 16 (including the silicon substrate) itself is thick like a crystalline silicon solar cell, the surface 56a of the spacer 56 and the translucent member 12 are melted as shown in FIG. The back surface 56b of the spacer 56 and the back glass plate 14 may be melt-bonded to each other.

  DESCRIPTION OF SYMBOLS 10 Solar cell module, 12 Translucent member, 14 Back surface glass plate, 14a Surface, 16 Photovoltaic device, 18 Metal terminal, 18a Conductive path, 20 Through-hole, 22 1st current collection wiring, 24 2nd current collection wiring , 32 laser device, 34 laser beam, 40 metal terminal, 40a glass part, 42 metal terminal, 43 through hole, 44 intermediate glass, 46 solder, 48 metal terminal, 50 connecting member, 52 crimp terminal, 56 spacer.

Claims (4)

A translucent member disposed on the light receiving side;
A back glass plate provided to face the translucent member;
A photovoltaic device provided between the translucent member and the back glass plate;
A terminal provided on the surface of the back glass plate, and having a conductive path for outputting the power generated in the photovoltaic device to the outside,
The back glass plate has a through hole formed,
The solar cell module, wherein the terminal is disposed so as to cover the through hole, and is melt-bonded to the back glass plate in at least a part of the periphery of the through hole.   The solar cell module according to claim 1, wherein the terminal is melt-bonded to the back glass plate over the entire circumference around the through hole. A conductive elastic member for conducting the terminal and the photovoltaic device;
The solar cell module according to claim 1, wherein the conductive elastic member is disposed in the through hole in an urged state. Preparing a translucent member provided with a photovoltaic device;
On the surface of the back glass plate in which the through hole is formed, a step of arranging a terminal having a conductive path for outputting the electric power generated in the photovoltaic device to the outside so as to cover the through hole,
A step of irradiating a laser beam having a pulse width of 1 nanosecond or less to the opposed portion of the back glass plate and the terminal around the through hole;
A step of making the translucent member and the back glass plate face each other and bonding a peripheral edge;
The manufacturing method of the solar cell module characterized by including.

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