JP2010267717A - Solar cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar cell module which can prevent module deformation in the laminating step, when a resin plastic is used for a back plate. <P>SOLUTION: This solar cell module M includes a sealing member 1 into which photovoltaic cells 11 are sealed, and a back plate assembly 2 is provided on the rear side of the sealing member 1. A back plate 21 in the back plate assembly 2 is made of the resin plastic, and the rear side is formed into a rugged shape. Furthermore, a translucent member 23 is provided between the back plate 21 and the sealing member 1, and the structure is made such that the thickness of the back plate 21 becomes substantially equal. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a solar cell module, and more particularly to a concentrating solar cell module provided with a back plate.

  A solar cell module having a structure in which a sealing material layer including solar cells is disposed between two light-transmitting members is known. As such a solar cell module, conventionally, a solar cell module including a layer including a solar battery cell, in which one main surface is an incident surface and the other main surface is a reflection surface has been disclosed (see, for example, Patent Document 1). ). In this solar cell module, the translucent member provided in the back surface material in the layer containing a photovoltaic cell is made uneven.

  In this solar cell module, a part of the light incident from one main surface side of the layer including the solar cell enters the solar cell. Moreover, the light that has not entered the solar battery cell is reflected by the reflecting surface. At this time, the reflection surface on the other surface has an uneven shape. This uneven shape is formed by alternately arranging a plurality of portions recessed toward the layer including the solar cells and portions protruding toward the opposite side of the layer including the solar cells. ing. The light reflected by the reflecting surface having such a shape is efficiently collected in the solar battery cell, and the light collection efficiency of the solar battery module becomes high.

Japanese Patent Laid-Open No. 11-307791 (FIG. 11)

  By the way, when manufacturing the solar cell module described in the said patent document 1, it is possible to use resin plastic or glass as a back surface material (back plate). Here, when glass is used, it is preferable to use a resin plastic because of problems such as difficulty in manufacturing, an increase in mass, and a brittle material.

  However, resin plastic is a material having high thermal expansibility. For this reason, in order to give unevenness to the reflective surface, if the resin plastic is provided with a thick part and a thin part, after being exposed to high temperature and high pressure in the lamination process when manufacturing a solar cell module There was a problem that module deformation caused by thermal deformation occurred when the temperature returned to room temperature.

  Then, the subject of this invention is providing the solar cell module which can prevent the module deformation | transformation in a lamination process, when resin plastic is used for a backplate.

  The solar cell module according to the present invention that has solved the above problems includes a sealing material layer in which solar cells are sealed, and is incident from the light incident surface on the opposite side of the light incident surface provided in the sealing material layer. The solar cell module is provided with a back plate on which a reflective surface for reflecting the reflected light is formed, and the reflective surface of the back plate is provided with an uneven shape, and the back plate is made of resin plastic and sealed. A light transmitting member is interposed between the stopper layer and the reflecting surface of the back plate.

  In the solar cell module according to the present invention, the light transmitting member is interposed between the sealing material layer and the reflective surface of the back plate, and the thickness of the back plate is substantially uniform. Module deformation due to thermal deformation in the laminating process is largely due to rigidity based on the difference in thickness of the back plate. For this reason, a light transmitting member is interposed between the sealing material layer and the reflective surface of the back plate, and the thickness of the back plate is made substantially uniform, thereby suitably preventing module deformation in the laminating process. Can do.

  Note that “substantially uniform” in the present invention does not mean that it is completely uniform, and there is a difference in width between the portion where the distance between the back plate and the sealing member is the longest and the portion where the shortest is the shortest. It means that it has been shortened.

  Here, it can be set as the aspect by which the thickness of the thick part in a backplate is adjusted substantially uniformly.

  As described above, the thickness of the thick portion of the back plate is adjusted to be substantially uniform, so that the back plate contracts uniformly when the back plate returns to room temperature even when thermal expansion occurs. For this reason, the module deformation | transformation in a lamination process can be prevented suitably.

  In addition, a solar cell module according to the present invention that has solved the above problems includes a sealing material layer in which a plurality of solar cells are sealed, and a light is provided on the opposite side of the light incident surface provided in the sealing material layer. A solar cell module in which a back plate on which a reflection surface for reflecting light incident from an incident surface is formed is provided, and an uneven shape is provided on the reflection surface of the back plate, wherein the plurality of solar cells are strings. The back plate and the strings form a fitting structure, and the strings are provided.

  In the solar cell module according to the present invention, the back plate and the strings form a fitting structure, and the strings are provided. For this reason, the position shift of the photovoltaic cell and the strings with respect to the back plate can be prevented. Therefore, the shape of the solar cell module can be accurately manufactured into a desired shape.

  At this time, the fitting structure is formed on the back plate and has a projection portion protruding toward the sealing member side and a fitting hole formed in the string and fitted into the projection portion. Can do.

  As described above, the protrusions are formed on the back plate, and the fitting holes that are fitted into the protrusions are formed in the strings, whereby the fitting structure can be easily formed.

  The strings may include an elastic member that expands and contracts along the extending direction of the strings, and the fitting hole is formed in a state of being supported by the elastic member.

  In this way, by forming the fitting hole in a state where it is supported by the elastic member that expands and contracts along the extending direction of the strings, it is possible to absorb the subtle displacement of the strings with respect to the back plate by the elastic member. it can.

  According to the solar cell module of the present invention, module deformation in the laminating process can be prevented when resin plastic is used for the back plate.

(A) is the perspective view which looked at the solar cell module which concerns on the 1st Embodiment of this invention from the upper side, (b) is the perspective view which looked at the solar cell module which concerns on embodiment of this invention from the lower side. is there. It is a sectional side view of a solar cell module. It is a principal part expanded side sectional view of a solar cell module. It is a disassembled perspective view of a solar cell module. It is a disassembled perspective view of a backplate assembly. It is a disassembled perspective view of a sealing member and a backplate assembly. It is a sectional side view of the solar cell module which shows the reflective state of sunlight. It is a sectional side view of a laminator. It is a side view of the solar cell module explaining the state along the front plate. It is a partial top view of the inner side of the sealing member in the solar cell module which concerns on 2nd Embodiment. (A) is a side view of the string in which the elastic part is formed, and (b) is a plan view of the string in which the elastic part of another aspect is formed. It is a perspective view of the backplate assembly concerning a 3rd embodiment. It is a figure which shows the solar cell module which carried out the bimetal deformation | transformation, (a) is a side view, (b) is a perspective view. It is a sectional side view which shows the solar cell module in a lamination process. (A) (b) is a sectional side view which shows the other example of a solar cell module. It is a sectional side view which shows the further another example of a solar cell module.

  Hereinafter, preferred embodiments of a solar cell module according to the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Also, the dimensional ratios in the drawings may differ from the actual ones.

  FIG. 1A is a perspective view of the solar cell module according to the first embodiment of the present invention as viewed from above, and FIG. 1B is a perspective view of the solar cell module according to the embodiment of the present invention as viewed from below. 2 is a side sectional view of the solar cell module, FIG. 3 is an enlarged side sectional view of a main part of the solar cell module, and FIG. 4 is an exploded perspective view of the solar cell module.

  As shown in FIG. 1, a frame F is attached around the solar cell module M according to the first embodiment. As shown in FIGS. 2 and 3, the solar cell module M includes a sealing member 1, and a back plate assembly 2 is disposed on the lower surface side of the sealing member 1. Further, a front plate 3 is disposed on the upper surface side of the sealing member 1. As shown in FIG. 1, a terminal box 4 is attached to the back side of the back plate assembly 2. The terminal box 4 is attached to the back side of the back plate assembly 2 using an adhesive such as butyl rubber. In FIG. 1, the illustration of the front plate 3 is omitted.

  The sealing member 1 includes a plurality of solar cells 11. Solar cell 11 is arranged such that its light receiving surface is parallel to the surface of sealing member 1. The plurality of solar cells 11 are electrically connected in series by strings 12. The strings 12 are attached to the solar cells 11 with a certain positional relationship. Furthermore, the plurality of solar battery cells 11 are arranged apart from each other in the direction along the surface of the sealing member 1. Further, the solar cells 11 and the strings 12 are enclosed in a sealing material layer 13.

  The sealing material layer 13 is composed of an ethylene-vinyl acetate copolymer (EVA). When forming the sealing material layer 13, as shown in FIG. 4, the EVA resin sheets 13A, 13A are sandwiched between two EVA resin sheets 13A, 13A and exposed to high temperature and high pressure. And then cooled to solidify the EVA resin sheet. Thus, the sealing material layer 13 enclosing the solar battery cell 11 is formed.

  The solar battery cell 11 includes a double-sided light receiving type that captures sunlight on both sides and a single-sided light receiving type that captures sunlight on one side. In this embodiment, the double-sided light receiving solar cell 11 is used. Examples of the solar cell 11 include a single crystal Si cell, a polycrystalline Si cell, a thin film Si cell, a III-V group cell, a compound cell, and an organic cell. Further, by using a single crystal Si cell or a polycrystal Si cell as the solar battery cell 11, the energy conversion efficiency can be improved.

  As shown in FIGS. 2 and 3, the back plate assembly 2 includes a back plate 21. The back plate is made of resin plastic, the buffer member 22 is provided on the upper layer side of the back plate, and the light transmitting member 23 is provided on the upper layer side of the buffer member 22. The back surface of the back plate 21 is a reflection surface 24 that reflects light incident from the front plate 3 side. The reflection surface 24 is formed in a concavo-convex shape in which a portion recessed toward the sealing member 1 side and a portion protruding toward the opposite side of the sealing member 1 are alternately arranged. . In generating the reflection surface 24, the back surface of the back plate 21 can be used as the reflection surface 24 as it is, or a metal thin film made of aluminum or silver is formed on the back surface side of the back plate 21 by vapor deposition or the like. The reflective surface 24 can also be used.

  Further, as shown in FIG. 5, a plurality of streak-shaped concave portions 21 </ b> A are formed on the surface of the back plate 21. A light transmitting member 23 is disposed in the streaky recess 21 </ b> A via a buffer member 22. The back plate 21 is formed with a recess 21A, and the light transmitting member 23 is disposed in the recess 21A, so that the thickness of the back plate 21 is substantially uniform. As the resin plastic in the back plate 21, polycarbonate is preferably used. As the buffer member 22, a member having a low Young's modulus and bonded by cross-linking is preferable. For example, an EVA resin can be preferably used.

  The light transmissive member 23 is light transmissive and is made of, for example, a transparent resin such as polycarbonate or glass. The light transmissive member 23 is a columnar body having a cut circular shape in which an end portion having a circular cross section is cut into a straight line. The light transmitting member 23 is accommodated and disposed in a recess 21 </ b> A formed in the back plate 21. A recess 21 </ b> A is formed on the surface of the back plate 21, and the light transmitting member 23 is provided, so that the thickness of the back plate 21 is uniform.

  Furthermore, between the recesses 21 </ b> A on the back plate 21, projections 25 are provided that are spaced apart at substantially equal intervals in the extending direction of the recesses 21 </ b> A. Further, the buffer member 22 is formed with a through hole 22A at a position corresponding to the position where the protrusion 25 is provided. For this reason, in the state in which the buffer member 22 and the light transmission member 23 are provided on the front surface side of the back plate 21, the protrusion 25 penetrates the through hole 22A. Thus, the protruding portion 25 protrudes from the front surface side of the back plate assembly 2.

  Further, as shown in FIG. 6, a plurality of through holes 12 </ b> A are formed in the strings 12 in the sealing member 1. These through holes 12 </ b> A are formed at positions corresponding to the protrusions 25 provided on the back plate 21. Further, the through hole 12 </ b> A has substantially the same diameter as the protrusion 25 provided on the back plate 21, and can be fitted into the protrusion 25. Thus, the fitting structure is configured by fitting the protrusions 25 provided on the back plate into the through holes 12 </ b> A formed in the strings 12. Further, the through hole 12A becomes a fitting hole.

  Furthermore, a front plate 3 that allows sunlight to enter is provided on the surface of the sealing member 1. As the front plate 3, soda glass, borosilicate glass, quartz glass, polycarbonate, acrylic resin, white plate tempered glass, or the like can be used. In particular, by using white plate tempered glass, it is possible to achieve excellent strength, heat resistance and long-term reliability.

  In the solar cell module M according to the present embodiment having the above configuration, sunlight L enters from the front plate 3 as schematically shown in FIG. Part of the sunlight L incident from the front plate 3 is absorbed by the solar cells 11, and the other part passes through the sides of the solar cells 11 and reaches the back plate 21. The sunlight L that has reached the back plate 21 is reflected by the reflecting surface 24 of the back plate 21 and travels again toward the solar battery cell 11.

  At this time, the reflection surface 24 of the back plate 21 is formed in an uneven shape. For this reason, as shown in FIG. 7, the light incident from the front plate 3 side and passing through the side of the solar cell 11 is directed toward the solar cell 11 reflected by the reflecting surface 24. . For this reason, the condensing efficiency in the photovoltaic cell 11 improves.

  Furthermore, in the solar cell module M according to the present embodiment, the buffer member 22 is provided between the back plate 21 and the light transmitting member 23 in the back plate assembly 2. For this reason, since the thermal contraction of the back plate 21 can be absorbed by the buffer member 22, the influence of the thermal contraction can be prevented from being given to the sealing member 1 and the front plate 3. Therefore, the deformation of the solar cell module M as a whole can be prevented.

  Further, when the solar cell module M is used outdoors, for example, the back plate 21 expands and contracts as the summer temperature rises and the winter temperature drops. On the other hand, since the buffer member 22 is provided, the expansion and contraction of the back plate 21 can be absorbed, so that the warpage of the solar cell module M can be prevented.

  Further, when polycarbonate or the like is used as the front plate 3, there is a problem that the strings 12 are easily corroded because they transmit moisture and are hygroscopic. Although it is conceivable to form a barrier layer by coating the surface of polycarbonate, there is a concern that the barrier layer may be damaged by external factors such as hail. In contrast, in the present embodiment, glass is used as the front plate 3. For this reason, it can be set as the front plate 3 excellent in durability and reliability.

  By the way, when manufacturing this solar cell module, the laminator 50 shown in FIG. 8 is used. The laminator 50 includes an upper chamber 51 and a lower chamber 52. A heater 53 is provided between the upper chamber 51 and the lower chamber 52, and a diaphragm 54 is provided at a position spaced apart from the upper chamber 51 in the heater 53. Also, vacuum pumps 55 and 56 are connected to the upper and lower chambers 51 and 52, respectively, so that the upper and lower chambers 51 and 52 can be in a vacuum state, respectively.

  When manufacturing the solar cell module, from the laminate in which the front plate 3, EVA resin sheet 13A, solar cells 11 and strings 12, EVA resin sheet 13A, and back plate assembly 2 shown in FIG. A solar cell module base material to be mounted is placed on the heater 53. Thereafter, the pressure in the lower chamber 52 is reduced to a vacuum state, so that the solar cell module base material is pressed by the diaphragm 54 and the solar cell module base material is heated by the heater 53. In this way, the solar cell module M is manufactured by laminating the solar cell module base material.

  Here, as the back plate 21 provided with the concavo-convex shape, it is conceivable to use glass manufactured by providing the concavo-convex shape by extrusion by a roll method or a resin plastic manufactured by injection molding. Among these, the glass is fragile and has a drawback that it is easily damaged during the lamination process. Therefore, a resin plastic can be suitably used as the back plate 21.

  However, even if resin plastic is used as the back plate 21, if the back plate 21 has an uneven shape and the back plate 21 is provided with portions having different thicknesses, the deformation of the back plate 21 during lamination is uneven. Will occur. When the deformation of the back plate 21 at the time of laminating becomes uneven, the back plate 21 that is heated and expanded is cooled and contracts unevenly when contracted, and the acting force to warp the front plate 3 is large. Become. As a result, as shown by a virtual line in FIG. 9, it is conceivable that the result is that the front plate 3 is warped.

  In this respect, in the solar cell module M according to the present embodiment, in the back plate assembly 2, the recess 21 </ b> A is formed in the back plate 21, and the light transmitting member 23 is disposed in the recess 21 </ b> A. It is almost uniform. For this reason, when the back plate 21 contracts during lamination, the entire back plate 21 can be contracted. As a result, since the relative rigidity with the front plate 3 is also reduced, the acting force for warping the front plate 3 can be reduced. Thus, module deformation in the laminating process can be suitably prevented.

  In particular, this tendency becomes remarkable when the front plate 3 is glass. The linear expansion coefficient coefficient differs greatly between the glass used for the front plate 3 and the polycarbonate used for the back plate 21. Further, in the laminating process when manufacturing the solar cell module M, the EVA resin is crosslinked and bonded at a temperature of about 150 ° C. For this reason, the linear expansion differs between the front plate 3 made of glass and the back plate 21 made of polycarbonate in the process of returning to room temperature after crosslinking the EVA resin. For this reason, module deformation due to warping of the front plate 3 is greatly generated. In this respect, in this embodiment, since the thickness of the back plate 21 is uniform, the acting force that warps the front plate 3 can be reduced, and module deformation in the laminating process can be suitably prevented.

  In the solar cell module according to this embodiment, the through holes 12A are formed in the strings 12 that electrically connect the solar cells 11, and the protrusions 25 provided on the back plate 21 penetrate the through holes 12A. The protrusion 25 of the back plate 21 is fitted to the strings 12. The strings 12 are attached to the solar battery cells 11 with a certain positional relationship. For this reason, when the protrusion part 25 of the back surface board 21 is fitted by the strings 12, the back surface board 21 and the photovoltaic cell 11 can be easily arrange | positioned to a fixed positional relationship. Therefore, since the sunlight reflected from the reflecting surface 24 of the back plate 21 can be collected with high accuracy with respect to the solar battery cell 11, power is generated with high efficiency without causing variations in individual outputs of the solar battery cell. be able to.

  Next, a second embodiment of the present invention will be described. The solar cell module according to the present embodiment is mainly different from the solar cell module according to the first embodiment in the configuration of strings. Hereinafter, the present embodiment will be described with a focus on differences from the first embodiment.

  FIG. 10 is a partial plan view of the inside of the sealing member in the solar cell module according to the present embodiment. As shown in FIG. 10, in the solar cell module according to this embodiment, the solar cell 11 and the strings 15 and 16 are provided, and the solar cell 11 is electrically connected by the strings 15 and 16. . Moreover, although not shown in figure, also in the solar cell module which concerns on this embodiment, many of these photovoltaic cells 11 and the strings 15 and 16 are provided.

  Among these, the first through holes 15A and the second through holes 16A are formed in the first strings 15 and the second strings 16, respectively. Of these, the first through hole 15A has a circular shape, and the second through hole 16A has an elliptical shape. Moreover, the protrusion part 25 (refer FIG. 5) formed in the backplate 21 has comprised the column shape, and the cross-sectional shape is made into the substantially same diameter as the cross-sectional shape of 15 A of 1st through-holes. Further, the second through hole 16A is arranged such that the short side of the second through hole 16A faces the direction in which the second strings 16 extend. The short side of the second through hole 16 </ b> A has substantially the same diameter as the diameter of the cross-sectional shape of the protrusion 25.

  Furthermore, the extending direction of the strings 15 and 16 is located at a position sandwiching the first through hole 15A in the first string 15 surrounded by a broken line in FIG. 10 and a position sandwiching the second through hole 16A in the second string 16 respectively. The elastic part is formed by an elastic member that extends and contracts along the spring, for example, a spring. Therefore, the first through hole 15A and the second through hole 16A are both supported by the elastic portion, and can vibrate in the direction along the extending direction of the first strings 15 or the second strings 16. Yes.

  As the elastic portion, for example, as shown in FIG. 11 (a), the elastic portion 15C can be given a wave shape in the vertical direction, and an elastic force can be applied. As shown in FIG. 11 (b), the elastic portion 15D can be provided. Elastic force can also be applied as a wave shape in the planar direction. Of course, the elastic force can be applied in other modes, or an elastic member can be provided separately.

  Further, the urging force of the elastic portion sandwiching the first through hole 15A is set to be approximately the same size with the first through hole 15A interposed therebetween. Similarly, the urging force of the elastic portion sandwiching the second through hole 16A is substantially the same size across the second through hole 16A. The solar cell module according to the present embodiment has the same configuration as that of the first embodiment with respect to other points.

  In the solar cell module according to the present embodiment having the above-described configuration, the reflection surface of the back plate has an uneven shape as in the first embodiment. For this reason, the condensing efficiency with respect to a photovoltaic cell can be improved. Moreover, since the buffer member is provided on the back plate, it is possible to prevent deformation of the corresponding battery module as a whole. And since the thickness of a backplate is made substantially uniform, the module deformation | transformation in a lamination process can be prevented suitably.

  By the way, in the said 1st Embodiment, since the projection part 25 of the backplate 21 fits in the through-hole 12A formed in the strings 12, and the backplate 21 is attached to the photovoltaic cell 11, back | inner_surface is attached. The face plate 21 and the solar battery cell 11 can be easily arranged in a certain positional relationship. However, there is a limit to the accuracy of dimensions such as the pitch between the solar cells 11. For this reason, for example, when 40 solar cells 11 are arranged with a deviation of about 0.2 mm at one pitch between the solar cells 11, an error as large as 8 mm can be generated.

  On the other hand, in the solar cell module according to the present embodiment, the positions of the strings 15 and 16 sandwiching the through holes 15A and 16A are respectively formed by elastic portions. The positions of the strings 15 and 16 sandwiching the through holes 15A and 16A are formed by elastic portions, respectively, so that the strings 15 and 16 expand and contract. For this reason, errors in dimensional accuracy can be absorbed by the expansion and contraction of the strings 15 and 16.

  In attaching the strings 15 and 16 to the solar battery cell 11, the solar battery cell 11 and the strings 15 and 16 are joined together by soldering or the like in a ladder shape. At this time, it is assumed that the dimensional accuracy is, for example, about ± 0.2 mm between cell pitches depending on the capability of the manufacturing equipment. In the case of dimensional accuracy under this process, the error can be sufficiently absorbed by the expansion and contraction of the strings 15 and 16. Therefore, each uneven shape of the back plate can be made to coincide with the solar cells 11 with high accuracy, so that the light collection efficiency with respect to the solar cells 11 can be further increased.

  In addition, the second through-hole 16A formed in the second string 16 has an elliptical shape formed of a long hole that is long in the longitudinal direction of the solar battery cell 11 (the direction orthogonal to the extending direction of the second string 16). . For this reason, a dimensional error in the longitudinal direction of the solar battery cell 11 can be absorbed by the long hole of the second through hole 16 </ b> A in the second string 16. Therefore, the position of the back plate with respect to the solar cells 11 in the longitudinal direction of the solar cells 11 can also be accurately arranged. Furthermore, by forming the elastic part and the long hole, it is possible to absorb the distortion due to the difference in thermal expansion generated between the front plate and the back plate. Therefore, high durability can be exhibited.

  Subsequently, a third embodiment of the present invention will be described. In the solar cell module according to the present embodiment, as shown in FIG. 12, the protrusion provided in the central region Y in the back plate assembly 2 is more than the protrusion provided in other regions in the back plate assembly 2. The amount of protrusion is small. About another point, it has the structure similar to the said 1st Embodiment.

  In the solar cell module according to the present embodiment having such a configuration, the reflection surface of the back plate has an uneven shape as in the first embodiment, as in the first embodiment. For this reason, the condensing efficiency with respect to a photovoltaic cell can be improved. Moreover, since the buffer member is provided on the back plate, it is possible to prevent deformation of the corresponding battery module as a whole. And since the thickness of a backplate is made substantially uniform, the module deformation | transformation in a lamination process can be prevented suitably.

  Moreover, in the solar cell module which concerns on this embodiment, it can contribute to reduction of the dispersion | variation in the EVA crosslinking rate which is the crosslinking rate of EVA contained in the sealing member 1 in a lamination process. In the laminating process in the laminator 50 shown in FIG. 8, as shown in FIG. 13, bimetallic deformation occurs in the solar cell module M due to the temperature difference between the upper and lower surfaces of the solar cell module M. Such bimetal deformation occurs in both the glass material and the polycarbonate, but it occurs remarkably in the polycarbonate. For this reason, it is desired to suppress bimetal deformation in the back plate made of polycarbonate.

  In this respect, in the solar cell module according to the present embodiment, in the preheating process of the laminate, the main press for EVA crosslinking for forming the sealing material layer 13 (FIG. 4) is performed at the second press pressure. As a pre-stage, the first press pressure is applied to suppress bimetal deformation. When pressurization by the first press pressure is performed, the protrusions 25 formed in the central region Y of the back plate assembly 2 are made minute so that bimetal deformation can be suitably suppressed.

For example, if the first press pressure is set to 50 kPa, the protrusions 25 in the central region Y are provided at 102 locations, and the protrusion shape is φ2 mm, the protrusion area is 320 mm ² . Note that the first press pressure can be set by providing a difference in pressure between the upper chamber and the lower chamber 52. On the other hand, the total load received by the first press pressure can be calculated from the module area.

  For example, when the module area is 700 mm × 500 mm, the pressure difference is 0.05 N / mm 2 at 50 kPa. When this pressure difference is multiplied by the area, the total load applied by the first press pressure is 17500 N. When the total load applied by the first press pressure is divided by the protrusion area, the compressive stress applied to the back plate 21 (FIG. 3) is calculated, and this compressive stress is 55 MPa.

  For example, if the yield stress when the polycarbonate is elastically deformed is 70 MPa, the deformation due to the 55 MPa compressive stress is elastic deformation. Therefore, EVA is not pressurized by the protrusion 25, the back plate 21 can be uniformly deformed with a load of 17500 N, and bimetal deformation can be suppressed.

  Next, in performing pressurization with the second press pressure, by applying a pressure of 100 kPa, the stress of the protrusion becomes about 110 MPa, which exceeds the yield stress of 70 MPa of the back plate 21. For this reason, since a projection part is crushed by plastic deformation, the positive pressure is applied to EVA resin, the dispersion | variation in EVA bridge | crosslinking can be reduced, and EVA bridge | crosslinking can be performed reliably.

  As described above, by adjusting the protrusion area of the protrusions, the first press pressure, and the second press pressure in the back plate assembly 2, variations in EVA cross-linking can be reduced. Furthermore, the clearance gap between the center part of the solar cell module M and an outer peripheral part can also be changed by changing the protrusion height and the number of arrangement | positioning of the protrusion part 25, for example. In this case, the air R flows as shown in FIGS. In this case, since it becomes difficult to eliminate the air R at the center of the solar cell module M, the clearance between the front plate 3 and the back plate 21 is provided closer to the outer periphery, thereby facilitating air removal. Can do. Thus, generation of voids in the laminating process can be suppressed.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. For example, in the above-described embodiment, the recesses 21A of the back plate 21 and the light transmitting member 23 are columnar bodies having a cut circular shape, but other forms may be employed. For example, as shown in FIG. 15 (a), a buffer member 62 is disposed in a concave portion of a back plate 61 in which a concave portion of a columnar body having a cross-sectional mountain shape is formed, and light transmission comprising a columnar body having a cross-sectional mountain shape is provided thereon. It can be set as the aspect which mounts the member 63. FIG. Alternatively, as shown in FIG. 15 (b), a buffer member 72 is disposed in a concave portion of the back plate 71 in which the concave portion of the cross-sectional corrugated columnar body is formed, and light transmission comprising the cross-sectional corrugated columnar body is provided thereon. It can be set as the aspect which mounts the member 73. FIG.

  Moreover, in the said embodiment, although the buffer member 22 is interposed between the backplate 21 and the light transmissive member 23, as shown in FIG. 16, a buffer member between the backplate 21 and the light transmissive member 23 is used. It can also be set as the aspect which does not provide. In this case, the concave portion 21 </ b> A of the back plate 21 and the light transmission member 23 are in direct contact. Furthermore, in the said embodiment, although the back plate is made into the aspect which is the polycarbonate which is resin plastic, in the aspect in which the through-hole is formed in the strings, the back plate is the aspect which consists of materials other than resin plastic, for example, glass It can also be.

  DESCRIPTION OF SYMBOLS 1 ... Sealing member, 2 ... Backplate assembly, 3 ... Front plate, 4 ... Terminal box, 11 ... Solar cell, 12 ... Strings, 12A ... Through-hole, 13 ... Sealing material layer, 13A ... Resin sheet, 15 ... 1st string, 15A ... 1st through-hole, 15C ... Elastic part, 15D ... Elastic part, 16 ... 2nd strings, 16A ... 2nd through-hole, 21 ... Back plate, 21A ... Recessed part, 22 ... Buffer member, 22A ... through-hole, 23 ... light transmitting member, 24 ... reflecting surface, 25 ... projection.

Claims (6)

A solar cell is provided with a sealing material layer that is sealed, and a reflection surface that reflects light incident from the light incident surface is formed on the opposite side of the light incident surface provided on the sealing material layer. A solar cell module in which a face plate is disposed and an uneven shape is imparted to the reflective surface of the back plate,
The back plate is made of resin plastic;
A solar cell module, wherein a light transmitting member is interposed between the sealing material layer and the reflective surface of the back plate.   The solar cell module according to claim 1, wherein a thickness of the thick portion of the back plate is adjusted substantially uniformly. The plurality of solar cells are electrically connected via strings,
The solar cell module according to claim 1 or 2, wherein the back plate and the strings form a fitting structure and the strings are provided. A plurality of solar cells are provided with a sealing material layer, and a reflective surface that reflects light incident from the light incident surface is formed on the opposite side of the light incident surface provided in the sealing material layer. A solar cell module in which a back plate is disposed and an uneven shape is imparted to the reflective surface of the back plate,
The plurality of solar cells are electrically connected via strings,
The solar cell module, wherein the back plate and the strings form a fitting structure and the strings are provided.   The said fitting structure is comprised by the projection part which is formed in the said back plate and protrudes toward the said sealing member side, and the fitting hole which is formed in the said strings and is engage | inserted by the said projection part. The solar cell module of Claim 3 or Claim 4.   The solar cell module according to claim 5, wherein the strings include an elastic member that expands and contracts along an extending direction of the strings, and the fitting hole is formed while being supported by the elastic member.

Images