JP2013012661A - Solar cell module and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell module having high power generation efficiency.SOLUTION: The solar cell module includes: a solar cell element 20; a translucent coating layer 30 covering the solar cell element 20; and a panel body 40 which is disposed on the coating layer 30 and comprises a first compressive stress layer 41, a tensile stress layer 42, and a second compressive stress layer 43 in order from the coating layer 30 side in a thickness direction. The second compressive stress layer 43 comprises a first region 43a positioned in a region overlapping the solar cell element 20 in a plan view and a second region 43b positioned in a region not overlapping the solar cell element 20 in a plan view and has a recess 44 for directing at least part of light incident on the second region 43b toward the solar cell element 20.

Description

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

  Solar cell elements using silicon semiconductor substrates are vulnerable to physical loads and impacts, and are used for a long period of time. Especially when solar cells are installed outdoors, it is necessary to protect them from rain and snow. is there. Moreover, since the electrical output generated by one solar cell element is small, it is necessary to connect a plurality of solar cell elements in series and parallel so that a practical electrical output can be taken out. For this reason, as shown in Patent Document 1, a plurality of solar cell elements are electrically connected by inner leads, and ethylene vinyl acetate is provided between a light-transmitting panel body on the light-receiving surface side and a protective panel on the back surface side. In general, it is used as a solar cell module arranged by being covered and encapsulated with a filler mainly composed of a copolymer (EVA) or the like.

JP 2004-200515 A

  However, in the technique described in Patent Document 1, most of the sunlight incident between the solar cell elements does not reach the solar cell element.

  The present invention has been devised under the above-described circumstances, and its purpose is to effectively utilize sunlight incident on a region that does not overlap with a solar cell element in a plan view to efficiently generate power. It is to provide a solar cell module and a manufacturing method thereof.

  The solar cell module of the present invention includes a solar cell element, a translucent coating layer that covers the solar cell element, and a first compressive stress layer disposed on the coating layer in order from the coating layer side in the thickness direction. A solar cell module comprising a panel body having a tensile stress layer and a second compressive stress layer, wherein the second compressive stress layer is located in a region overlapping the solar cell element in plan view; A second region located in a region that does not overlap the solar cell element in plan view, and a recess for directing at least part of the light incident on the second region toward the solar cell element.

  Moreover, the manufacturing method of the solar cell module of this invention arrange | positions the translucent coating layer which covers these solar cell elements on several solar cell elements, and the said coating layer side in the thickness direction on this coating layer. A panel body having a first compressive stress layer, a tensile stress layer, and a second compressive stress layer is arranged and assembled in order, and an assembly process, and in a region that does not overlap the solar cell element of the panel body in plan view, A recess that does not reach the tensile stress layer from the side of the compressive stress layer; a first region located in a region overlapping the solar cell element when viewed from above the second compressive stress layer; And a panel body processing step of processing so as to be provided with a second region that is located in a region that does not overlap with the solar cell element and has the concave portion on the upper surface.

  According to the present invention, it is possible to effectively utilize sunlight incident on a region that does not overlap with the solar cell element in plan view, and thus it is possible to provide a solar cell module with high power generation efficiency.

(A), (b) is the top view which shows an example of embodiment of this invention, respectively, and sectional drawing in the II line. It is sectional drawing which shows the other example of embodiment of this invention. It is sectional drawing which shows the other example of embodiment of this invention. It is sectional drawing which shows the other example of embodiment of this invention. (A)-(c) is sectional drawing which shows the manufacturing process of the solar cell module of this invention, respectively.

  An example of an embodiment of the solar cell module of the present invention will be described with reference to the drawings.

(First embodiment)
FIGS. 1A and 1B are a plan view and a cross-sectional view in a see-through state showing the solar cell module 10 of the first embodiment of the present invention.

  As shown in FIG. 1, the solar cell module 10 includes a solar cell element 20, a translucent coating layer 30 that covers the solar cell element 20, and a panel body 40 on the coating layer 30. In this example, there are a plurality of solar cell elements 20 (21 to 24), and they are arranged at intervals. Moreover, the protection panel 50 is provided in the surface (lower surface of FIG.1 (b)) on the opposite side to the side in which the panel body 40 is arrange | positioned so that these solar cell elements 20 may be supported. Thus, the solar cell element 20 is hermetically sealed with the panel body 40, the covering layer 30, and the protective panel 50. In practice, there are inner leads for electrically connecting the plurality of solar cell elements 21 to 24 to each other, but the illustration is omitted.

  In the solar cell element 20, a reverse conductivity type semiconductor layer is formed on a one conductivity type semiconductor substrate, and a surface on which the semiconductor layer is disposed serves as a light receiving surface. An example of such a semiconductor material is silicon (Si). A semiconductor layer may be formed by using a p-type silicon single crystal substrate as a semiconductor substrate and diffusing an n-type dopant on the upper surface thereof. Current collecting electrodes (bus bar electrodes, finger electrodes, etc.) are formed on the light receiving surface side and the back surface side of the solar cell element 20 using silver (Ag), aluminum (Al), or the like.

  The covering layer 30 is made of a light-transmitting insulating material and covers at least the light receiving surface side (upward direction in FIG. 1B) of the solar cell element 20. In order to protect the solar cell element 20, in consideration of covering properties, for example, a resin material mainly composed of ethylene vinyl acetate copolymer (EVA) or the like can be used.

  The panel body 40 is made of a translucent material, and is disposed on the upper surface of the covering layer 30 (upward direction in FIG. 1B). The panel body 40 is required to have high strength in order to protect the solar cell element 20 from external impacts such as loads of snow and people, and for example, tempered glass can be used. The translucency etc. of the material which comprises the panel body 40 will not be specifically limited if the sunlight received on the upper surface of the panel body 40 can reach the light-receiving surface of the solar cell element 20 efficiently. In order to prevent unintentional scattering of sunlight at the interface between the coating layer 30 and the panel body 40, it is preferable that the panel body 40 is made of a material having a refractive index comparable to that of the coating layer 30.

Here, the panel body 40 has the 1st compressive stress layer 41, the tensile stress layer 42, and the 2nd compressive stress layer 43 in an order from the coating layer 30 side in the thickness direction (up-down direction of FIG.1 (b)). For example, the panel body 40 made of tempered glass used in this example has first and second compressive stress layers 41 and 43 having a film thickness of about 1/6 of the total thickness, and the outermost surfaces (panels) The compressive stress in the upper and lower surfaces of the body 40 was about 100 MPa.

  The second compressive stress layer 43 has a first region 43a that overlaps the solar cell element 20 in plan view, and other non-overlapping second regions 43b. The second region 43 b has a recess 44 that guides at least part of light (sunlight) incident on the panel body 40 to the solar cell element 20. Conventionally, the sunlight incident on the second region 43b reaches the solar cell elements 20 as it is and cannot contribute to power generation. However, by providing the recess 44, it is possible to scatter and refract sunlight incident on the second region 43b, change the optical path, and direct it toward the solar cell element 20. Thereby, it is possible to efficiently use sunlight incident on the entire solar cell module 10 and to have high power generation efficiency. Then, a layer (43) subjected to compressive stress is provided on the upper surface side of the panel body 40, and the recess 44 is provided within the range of the layer subjected to compressive stress (second compressive stress layer 43). Even if 40 is comprised with the tempered glass which is difficult to process, generation | occurrence | production of a crack etc. can be suppressed. That is, it is possible to form a configuration in which sunlight incident on the second region 43 b is directed toward the solar cell element 20 while maintaining the strength and reliability of the panel body 40.

Such a recess 44 only needs to have an inclined portion in a cross-sectional shape in a cross section perpendicular to the panel body 40 and crossing the solar cell element 20. For example, it may be V-shaped, may have a plurality of inclined surfaces with different angles, or may be curved. In order to achieve an effect without depending on the incident angle of sunlight with respect to the main surface of the panel body 40, it is preferable that the inclination angle in the cross section changes continuously. More preferably, as shown in FIG. 1, the cross-sectional shape of the recess 44 is preferably a curved surface in a cross section that is perpendicular to the panel body 40 and passes through the center line of the plurality of solar cell elements 20. .

  The shape of the recess 44 in plan view may be a plurality of circular shapes having a smaller diameter than one side of the solar cell element 20 or a rectangular shape having a shorter side than one side of the solar cell element 20. Alternatively, a donut shape surrounding the solar cell element 20 may be used. In the example shown in FIG. 1A, the solar cell elements 20 are arranged in parallel with the arrangement direction of the solar cell elements 21 and 22 and the solar cell elements 21 and 23 as a rectangular shape having a longer side than one side of the solar cell element 20. . In other words, it is a lattice shape that fits between the plurality of solar cell elements 20.

  In FIG. 1A, the arrangement interval d1 between the solar cell elements 21 and 22 and the width d2 of the recess 44 in the arrangement direction of the solar cell elements 21 and 22 so that the positional relationship between the solar cell element 20 and the recess 44 is clear. However, preferably, as shown in FIG. 1B, the arrangement interval d1 of the solar cell elements 21 and 22 and the width d2 of the recess 44 are preferably substantially the same. Similarly, it is preferable that the arrangement interval d3 between the solar cell elements 21 and 23 and the width d4 of the concave portion 44 are substantially the same.

  Here, the panel body 40 is required to have strength as described above, but on the other hand, the ductility is not necessarily high. For example, when tempered glass is used as the panel body 40, ductility is low and processing is difficult. Further, stress may be applied after processing to cause cracks. For this reason, it is preferable to further increase the strength of the surface layer region in which the recess 44 is formed in the second region 43b. Specifically, it is preferable that the compressive stress per unit volume in the surface layer region in which the recess 44 is formed is larger than the compressive stress per unit volume in the surface layer region of the first region 43a. By setting it as such a structure, generation | occurrence | production of a crack can be suppressed, without having a bad influence on translucency.

  The protection panel 50 is a flat plate that supports and protects the solar cell element 20 together with the covering layer 30 and the panel body 40. For example, polyethylene phthalate (PET), metal foil made of polyvinyl fluoride resin (PVF), or the like. It is composed of things sandwiched between.

  By setting it as the above structures, the solar cell module 10 which can utilize effectively the sunlight which injected into the area | region which does not overlap with the solar cell element 20 by planar view can be provided.

(Second Embodiment)
A solar cell module 10A according to the second embodiment of the present invention will be described with reference to FIG.

  The solar cell module 10 </ b> A is different from the solar cell module 10 in the configuration of the second region 43 </ b> Ab, and other parts are the same as the solar cell module 10. Only different points will be described below.

  In the solar cell module 10A, the upper surface side of the second region 43Ab of the panel body 40A has a recess 44A and a curved protrusion 45A adjacent to the recess 44A. The protrusion 45A has a height smaller than the depth in the thickness direction of the recess 44A. Here, “adjacent to the recess 44A” means that the skirt portion of the protrusion 45A is adjacent to the edge 44Aa of the region where the recess 44A is formed. The protrusion 45A can also be formed, for example, by irradiating the panel body 40 in the vicinity of the region where the protrusion 45A is to be formed with conditions of laser light.

  By adopting such a configuration, it is possible to suppress the reflection of sunlight at the edge 44Aa (intersection with the portion parallel to the main surface) of the recess 44A in the second region 43Ab, and thus a more efficient solar cell. The module 10A can be used. Moreover, since the chipping at the edge 44Aa of the recess 44A can be prevented and the edge 44Aa can be prevented from becoming a starting point of destruction, the reliability of the solar cell module 10A can be improved. Furthermore, when installing such a solar cell module 10A on a roof, since it is highly reliable as described above, it can be made highly workable.

(Third embodiment)
Next, a solar cell module 10B according to a third embodiment of the present invention will be described using FIG.

  The solar cell module 10 </ b> B is different from the solar cell module 10 in the configuration of the first compressive stress layer 41 </ b> B constituting the panel body 40 </ b> B, and other parts are the same as the solar cell module 10. Only different points will be described below.

  In the solar cell module 10B, the first compressive stress layer 41B has a second recess 46B on the lower surface (downward in FIG. 3). In other words, the second compressive stress layer 41B is provided on the surface of the first compressive stress layer 41B on the side in contact with the coating layer 30B. The second recess 46B is filled with the coating layer 30B. In other words, the upper surface of the coating layer 30B has a raised portion along the second recess 46B of the first compressive stress layer 41B. With such a configuration, unintended reflection / loss of sunlight can be suppressed between the second recess 46B and the coating layer 30B.

  A plurality of such second recesses 46B may be provided, but each size is preferably equal to or less than the depth of the recess 44B and the width in plan view. By providing the second recess 46B, the stress generated in the panel body 40B due to the presence of the recess 44B can be relaxed.

  More preferably, as shown in FIG. 3, the second recess 46B having the same size as the recess 44B is formed at a position overlapping the region where the recess 44B is formed in plan view. With such a configuration, it is possible to suppress warping of the panel body 40B and to suppress generation of unnecessary stress.

  When the refractive index difference between the coating layer 30B and the first compressive stress layer 41B of the panel body 40B is smaller than the refractive index difference between the second compressive stress layer 43B and the atmosphere, the second recess 46B is You may arrange | position in the position which overlaps with 1st area | region 43Ba by planar view.

  By setting it as such a structure, the more reliable solar cell module 10B can be provided.

(Fourth embodiment)
Next, a solar cell module 10C according to a fourth embodiment of the present invention will be described using FIG.

  The solar cell module 10 </ b> C is different from the solar cell module 10 in the shape of the recess 44 </ b> C, and the other portions are the same as the solar cell module 10. Only different points will be described below.

  In the cross section passing through the center line of the solar cell element 20C, the recess 44C is steeper as the inclination angle with respect to the main surface of the panel body 40C approaches the center in the width direction of the second region 43Cb. By setting it as such a structure, the inclination | tilt angle of the recessed part 44C becomes large as it leaves | separates from the solar cell element 20. FIG. Sunlight incident on the vicinity of the center of the second region 43Cb of the panel body 40C needs to be refracted greatly because it is away from the solar cell element 20. Therefore, by adopting a configuration like the concave portion 44 </ b> C, sunlight incident in a region away from the solar cell element 20 in a plan view can be guided to the solar cell element 20.

(Production method)
Next, a method for manufacturing the solar cell module as described above will be described with reference to FIG. 4, taking the solar cell module 10 shown in FIG. 1 as an example.

(Assembly process)
First, as shown to Fig.4 (a), the several solar cell element 20 is prepared, they are electrically connected in series and parallel using an inner lead not shown, and it arrange | positions on the protection panel 50, Cover with a coating layer 30. Specifically, the lower surface of the solar cell element 20 is formed so as to be filled with a coating layer (filling layer) 30.

  Next, as shown in FIG. 4B, the panel body in which the first compressive stress layer 41, the tensile stress layer 42, and the second compressive stress layer 43 are laminated, and the first compressive stress layer 41 is combined with the coating layer 30. The panel body 40 is disposed on the upper surface of the coating layer 30 so as to be in contact with each other.

(Panel body processing process)
Next, as shown in FIG. 4C, a recess 44 that does not reach the tensile stress layer 42 from the second compressive stress layer 43 side is formed in a region that does not overlap the solar cell element 20 of the panel body 40 in plan view. To do. The recess 44 can be formed by appropriately selecting mechanical processing such as sand blasting and dicing, and chemical processing such as etching.

Here, the formation of the recess 44 is preferably performed by laser processing. By carrying out laser processing, the dimension in the depth direction can be accurately controlled, so that the concave portion 44 can be surely accommodated in the second compressive stress layer 43, and no cracks are generated. It can be. Moreover, the surface which forms the recessed part 44 becomes spherical shape by performing laser processing. In other words, the cross-sectional shape in a cross section crossing the solar cell element 20 is a spherical shape. Thereby, power generation efficiency can be improved irrespective of the incident angle of sunlight. Further, by laser processing, heat is applied to the processed surface (surface layer region where the recess 44 is formed), and the compressive stress can be increased as compared with other regions. Thereby, the strength deterioration due to the formation of the recess 44 can be suppressed, and the reliability becomes high.

  By going through the process of FIG. 4C, the second compressive stress layer 43 is located in a region overlapping the solar cell element 20 in plan view, and a region not overlapping the solar cell element 20 in plan view. And a second region 43b having a recess 44 on the upper surface.

  By going through the steps up to here, the solar cell module 10 is made.

  Note that a panel body processing step may be performed prior to the assembly step. That is, in accordance with the shape of the solar cell element 20 to which the panel body 40 is applied, the recess 44 is formed in the panel body in advance and processed so as to have the first region 43a and the second region 43b, and then the coating layer The panel body 40 may be arranged on the upper surface of 30 such that the first region 43a and the solar cell element 20 overlap in plan view. In other words, what is necessary is just to arrange | position so that the area | region in which the recessed part 44 was formed may not overlap with the solar cell element 20 by planar view.

  Moreover, you may form the panel body 40 using the roll which has a processus | protrusion according to the shape of the recessed part 44 by the rollout method. That is, you may use what the recessed part 44 was previously formed in the surface of the tempered glass used as the panel body 40. FIG.

  In addition, this invention is not limited to the above-mentioned example, A various change can be added within the scope of the present invention. For example, in the present embodiment, an example in which a plurality of solar cell elements 20 are provided has been described.

DESCRIPTION OF SYMBOLS 10 ... Solar cell module 20 ... Solar cell element 30 ... Cover layer 40 ... Panel body 41 ... 1st compressive stress layer 42 ... Tensile stress layer 43 ... 2nd compressive stress Layer 43a ... 1st area | region 43b ... 2nd area | region 44 ... Recess 45A ... Projection part 50 ... Protection panel

Claims (7)

A solar cell element;
A translucent coating layer covering the solar cell element;
A solar cell module comprising a panel body disposed on the coating layer and having a first compressive stress layer, a tensile stress layer, and a second compressive stress layer in order from the coating layer side in the thickness direction,
The second compressive stress layer has a first region located in a region overlapping with the solar cell element in plan view, and a second region located in a region not overlapping with the solar cell element in plan view,
The solar cell module which has a recessed part for directing at least one part of the light which injects into this 2nd area | region to the said solar cell element.   2. The solar cell module according to claim 1, wherein a compressive stress per unit volume in the surface layer region in which the concave portion of the second region is formed is larger than a compressive stress per unit volume in the first region.   The solar cell module according to claim 1, wherein the recess has a curved cross-sectional shape perpendicular to the panel body and passing through the solar cell element.   2. The solar cell module according to claim 1, further comprising a curved protrusion having a height smaller than the depth of the recess adjacent to the recess on the upper surface of the second region. The refractive index difference between the coating layer and the first compressive stress layer is smaller than the refractive index difference between the second compressive stress layer and the atmosphere,
2. The solar cell module according to claim 1, wherein the first compressive stress layer has a second recess on a lower surface for relieving stress generated in the panel body by the recess. A translucent coating layer covering these solar cell elements is disposed on the plurality of solar cell elements, and the first compressive stress layer, the tensile stress layer, and the second layer are sequentially formed on the coating layer from the coating layer side in the thickness direction. An assembly process for arranging and assembling a panel body having a compressive stress layer;
A concave portion that does not reach the tensile stress layer from the second compressive stress layer side is formed in a region that does not overlap with the solar cell element of the panel body in plan view, and the panel body is formed into the second compressive stress layer. A first region located in a region overlapping with the solar cell element in a plan view and a second region located in a region not overlapping with the solar cell element in a plan view and having the concave portion on the upper surface. The manufacturing method of a solar cell module including the panel body process process to do. The method for manufacturing a solar cell module according to claim 6, wherein the recess is formed by laser processing in the panel body processing step.

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