Soldering device, solar cell module, and method for manufacturing a solar cell module

Abstract

To provide a soldering device capable of restricting adhesive failure of solder, a solar cell module capable of securing a conductive path even if adhesive failure of a solder layer occurs, and a manufacturing method of a solar cell module in which adhesive failure of solder is less likely to occur compared to conventional methods.SOLUTION: A soldering device for melting solder to bond a solar cell and a wiring member includes: a heating member with a long shape; and a lifting / lowering mechanism for lifting / lowering the heating member in a vertical direction. The heating member has a plurality of heating contact parts and a plurality of recesses. The plurality of recesses are formed at intervals in a longer direction of the heating member. The plurality of heating contact parts are capable of heating solder and are partitioned by the plurality of recesses.SELECTED DRAWING: Figure 12

Description

Technical Field

[0001] The present invention relates to a soldering device, a solar cell module, and a method for manufacturing a solar cell module.

Background Art

[0002] Conventionally, a solar cell module having a solar cell string in which a plurality of solar cells are arranged in parallel and connected in series is known (for example, Patent Document 1). In the solar cell module of Patent Document 1, of adjacent solar cells, a portion on the end side of one solar cell is overlapped with a portion on the end side of the other solar cell, and the bus bar electrode portions are adhered to each other with a silver paste at that portion. By doing so, the filling factor of the solar cells is improved and the module efficiency is increased.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in order to connect between each solar cell string or to extract electricity from each solar cell string, it is necessary to connect a tab wire to the end of each solar cell string. Therefore, the inventor of the present invention attempted to connect a tab wire to the end of a solar cell string following the solar cell module of Patent Document 1. Specifically, the inventor of the present invention utilized the advantage that the bus bar electrode of the solar cell string of Patent Document 1 has a bus bar electrode portion extending in a direction orthogonal to the parallel arrangement direction of the solar cell, and prototyped a solar cell module in which the tab wire was adhered with solder to the entire surface of the bus bar electrode portion along the extending direction of the bus bar electrode portion. By adopting such a structure, a large adhesion area can be ensured, and it was considered that the adhesion strength was improved compared with the conventional case.

[0005] However, in the prototype solar cell modules, some exhibited expansion of the wiring due to differences in thermal expansion coefficients, and others had gaps between the wiring components and the busbar electrodes of the solar cells, resulting in poor solder adhesion.

[0006] Therefore, the object of the present invention is to provide a soldering apparatus that can suppress solder adhesion defects, a solar cell module that can secure a conductive path even if there are solder layer adhesion defects, and a method for manufacturing a solar cell module that is less prone to solder adhesion defects than conventional methods. [Means for solving the problem]

[0007] One aspect of the present invention for solving the above-mentioned problems is a soldering device for melting solder to bond a solar cell and a wiring member, comprising a long heating member and a lifting mechanism for raising and lowering the heating member vertically, wherein the heating member has a plurality of heating contact portions and a plurality of recesses, the plurality of recesses are formed at intervals in the longitudinal direction of the heating member, the plurality of heating contact portions are capable of heating the solder and are partitioned by the plurality of recesses.

[0008] According to this design, the heating element is long and allows for soldering of the wiring components in one go, making it easier to control the amount of heat applied to the wiring components and solar cells. According to this configuration, since a recess is provided between the heating contact areas, even if the wiring member expands due to the heating of the solder, the wiring member will move into the recess. This makes it less likely for the wiring member to lift at the adhesive area, and thus suppresses solder adhesion defects caused by the thermal expansion of the wiring member when the solder is heated.

[0009] A preferred configuration is one in which the spacing between adjacent heating contact portions in the longitudinal direction of the heating member is 1.5 mm or more and 3.5 mm or less.

[0010] According to this pattern, it is possible to ensure sufficient bonding strength by soldering while relieving stress on the wiring components.

[0011] A preferred configuration is one in which the multiple heating contact portions are arranged at equal intervals in the longitudinal direction.

[0012] According to this pattern, the wiring component and the solar cell can be evenly bonded by solder, which further relieves stress on the wiring component and ensures higher adhesive strength.

[0013] A preferred configuration includes an operating section, the lifting mechanism being capable of raising and lowering the heating member by operating the operating section, and the lifting mechanism comprising a biasing member that biases the heating member in the upward direction.

[0014] According to this configuration, since the heating element is biased upward by the biasing member, it is easy for the operator to adjust the pressure on the heating contact area when lowering the heating element by operating the control unit, thereby preventing excessive pressure on the wiring element and preventing cracking of the solar cell.

[0015] One aspect of the present invention is a solar cell module comprising a solar cell, a wiring member, and a solder layer, wherein the solar cell has a busbar electrode portion, the busbar electrode portion extends in a predetermined direction, the wiring member overlaps the busbar electrode portion when viewed from above, and has an adhesive region where the busbar electrode portion and the wiring member are bonded by the solder layer, and an unadhesive region where the busbar electrode portion and the wiring member are not bonded by the solder layer, and the wiring member has a plurality of bulging portions in the unadhesive region that bulge in a direction away from the solar cell, and the plurality of bulging portions are arranged at intervals in the predetermined direction.

[0016] According to this aspect, since the wiring component is bonded to the busbar electrode portion by solder layers at multiple points, a conductive path can be secured even if there are adhesion problems in the solder layers.

[0017] A preferred configuration is that the solar cell has one side, the busbar electrode portion is provided along the side, and the maximum distance from the side is 160 mm or less.

[0018] According to this aspect, since the distance from the bus bar electrode portion to one side is short, the wiring member is unlikely to obstruct the light reception of the solar cell.

[0019] One aspect of the present invention is a method for manufacturing a solar cell module in which a wiring member is adhered to a bus bar electrode portion of a solar cell using the soldering device described above, the method including a step of placing a wiring member having a solder layer coated on a surface thereof on the bus bar electrode portion of the solar cell, and a step of melting a part of the solder layer on the surface of the wiring member by bringing the heating contact portion close to or into contact with the wiring member.

[0020] According to this aspect, poor adhesion of the solder layer is less likely to occur compared to the prior art.

Advantages of the Invention

[0021] ]>According to the soldering device of the present invention, poor adhesion of the solder can be suppressed. According to the solar cell module of the present invention, even if there is poor adhesion of the solder layer, a conductive path can be ensured. According to the method for manufacturing a solar cell module of the present invention, poor adhesion of the solder is less likely to occur compared to the prior art.

Brief Description of the Drawings

[0022] [Figure 1] It is a right side view of the soldering device according to the first embodiment of the present invention in a natural state. [Figure 2] It is a left side view of the soldering device of FIG. 1 in a natural state. [Figure 3] It is a front view of the soldering device of FIG. 1 in a natural state. [Figure 4] It is an explanatory view of the heating member of FIG. 1, where (a) is a perspective view of the heating member and (b) is a front view of the heating member. [Figure 5]This is an explanatory diagram of a solar cell module according to the first embodiment of the present invention, where (a) is a schematic perspective view of the solar cell module, and (b) is a cross-sectional view AA of (a), with the hatching of the first and second sealing sheets omitted for ease of understanding. [Figure 6] Figure 5(a) is a cross-sectional perspective view of the main part of the solar cell module, with the first sealing sheet, second sealing sheet, and second protective member omitted for ease of understanding. [Figure 7] Figure 6 is a plan view of the main components of the solar cell module. [Figure 8] Figure 7 is a cross-sectional view of the main part of the solar cell module, where (a) is an end view of the BB section of Figure 7, and (b) is a cross-sectional view of the CC section of Figure 7. [Figure 9] Figure 6 is an explanatory diagram of the solar cell, where (a) is a plan view from the first main surface and (b) is a plan view from the second main surface. [Figure 10] Figure 1 is a side view of the soldering apparatus when the operating handle is operated and lowered. [Figure 11] Figure 1 is an explanatory diagram illustrating the relationship between the soldering device, solar cells, and wiring components when soldering using the soldering device shown in Figure 1. (a) is a cross-sectional view of the main part immediately before soldering, and (b) is a cross-sectional view of the main part midway through soldering. [Figure 12] Figure 1 is an explanatory diagram illustrating the relationship between the soldering device, solar cells, and wiring components when soldering using the soldering device shown in Figure 1. (a) is a cross-sectional view of the main part immediately after soldering, and (b) is a perspective view of the main part when the heating element is removed. [Figure 13] This is an explanatory diagram of a heating member according to another embodiment of the present invention, where (a) is a front view when the recess is triangular in shape, and (b) is a front view when the recess is semicircular in shape. [Modes for carrying out the invention]

[0023] Embodiments of the present invention will be described in detail below. Unless otherwise specified, the vertical positional relationship of the soldering device 1 is based on the no-load state, i.e., the natural state, when the operator is not operating the operating handle 10, as shown in Figure 1.

[0024] The soldering apparatus 1 of the first embodiment of the present invention adheres a connecting wiring member 111 to the collector electrodes 121 and 122 of a solar cell 110 using solder. As shown in Figures 1 and 10, the soldering device 1 is a lifting type soldering iron device in which the heating element 12 moves vertically up and down by a lifting mechanism, and is a semi-automatic soldering iron device in which the operator performs soldering by operating the operating handle 10. As shown in Figures 1 to 3, the soldering apparatus 1 comprises a base portion 2, a main shaft portion 3, a stand portion 5, a biasing member 6, a position fixing portion 7, a guide shaft portion 8, an operating handle portion 10, a support portion 11, and a heating member 12. Furthermore, the soldering apparatus 1 of this embodiment has one of its main features in the heating element 12. Based on this, the individual components will now be described.

[0025] (Base section 2) The base section 2 is the part that forms the base of the soldering device 1 and includes a mounting section 20 on which the workpiece, the solar cell 110, is placed.

[0026] (Main shaft part 3) The main shaft section 3 is a rod-shaped column that is erected (upright) from the base section 2 and extends in the vertical direction. As shown in Figures 1 and 2, the main shaft section 3 is equipped with a first angle adjustment section 25 in the middle of the vertical direction. By operating the first angle adjustment unit 25, the main shaft unit 3 rotates relative to the base unit 2 in the circumferential direction, making it possible to adjust the relative angle of the heating element 12 with respect to the solar cell 110 on the mounting portion 20 of the base unit 2.

[0027] (Stand section 5) The stand section 5 is a head that fixes the support section 11 and the heating element 12 to the main shaft section 3, and includes a guide position adjustment section 30 for adjusting the vertical position of the guide shaft section 8, as shown in Figure 2. The guide position adjustment unit 30 allows for adjustment of the relative position of the guide shaft 8 with respect to the stand 5 by operating it. The guide position adjustment section 30 in this embodiment is a wing bolt, which allows the vertical relative position of the guide shaft 8 with respect to the stand 5 to be adjusted by loosening it, and allows the guide shaft 8 to be tightened and its vertical relative position with respect to the stand 5 to be fixed by tightening it.

[0028] (Biasing member 6) The biasing member 6 is an elastic member having elasticity, and as shown in Figures 1 and 2, it is provided so as to surround the main shaft portion 3 and is a member that biases the stand portion 5 upward along the main shaft portion 3. The biasing member 6 is specifically a compression spring, which is spirally wound around the main shaft portion 3. That is, when a compressive force is applied from the stand portion 5, the biasing member 6 elastically deforms, and its restoring force makes it possible to bias the stand portion 5 upward.

[0029] (Position fixing part 7) The position fixing part 7 is a part that adjusts the upper limit position of the stand part 5, and engages with a part of the stand part 5 to restrict the upward movement of the stand part 5. As shown in Figure 1, the position fixing unit 7 includes a position adjustment unit 31 for adjusting the vertical position of the position fixing unit 7. In this embodiment, the position adjustment section 31 is a clamp screw, which restricts the movement of the main shaft section 3 of the position fixing section 7 in the extension direction (up and down direction) when tightened, and allows the main shaft section 3 of the position fixing section 7 to move in the extension direction (up and down direction) when loosened.

[0030] (Guide shaft portion 8) The guide shaft portion 8 is a restricting member that restricts the movement direction of the stand portion 5 in the vertical direction, and as shown in Figure 1, it is a rod-shaped stop bar that extends parallel to the axial direction of the main shaft portion 3.

[0031] (Operating handle section 10) The operating handle section 10 is an operating section operated by the operator, and is a rod-shaped body that is inclined with respect to the guide shaft section 8. As shown in Figure 1, the operating handle section 10 is connected to the stand section 5 and the position fixing section 7 via a link mechanism 32, and the rotational force of the operating handle section 10 can be converted into vertical movement force of the stand section 5 via the link mechanism 32.

[0032] (Support part 11) As shown in Figure 1, the support portion 11 is located at the bottom of the stand portion 5 and is the part that supports the heating element 12. The support section 11 includes a support shaft section 35, a support bracket section 36, and a second angle adjustment section 37. The second angle adjustment section 37 is a part that adjusts the angle of the support bracket section 36 with respect to the circumferential direction of the support shaft section 35, and adjusts the relative angle of the heating member 12 with respect to the solar cell 110 on the mounting section 20 of the base section 2. The second angle adjustment section 37 in this embodiment sandwiches the support shaft section 35, allowing the support shaft section 35 to move in the circumferential direction by loosening it, and restricting the circumferential movement of the support shaft section 35 by tightening it. By operating the second angle adjustment unit 37, the support unit 11 can be rotated relative to the stand unit 5, and by rotating it, the angle of the heating element 12 relative to the solar cell 110 can be adjusted.

[0033] (Heating element 12) The heating element 12 is a heating heater that heats the solder layer 156 on the surface of the connecting wiring element 111. As shown in Figure 4(a), the heating element 12 is a long, rectangular member that extends in a predetermined direction (longitudinal direction A1) in a wave-like shape, and when viewed from the front, it has an uneven shape with alternating convex and concave portions. As shown in Figure 4(b), the heating element 12 of this embodiment has a rectangular wave-like uneven shape when viewed from the front. As shown in Figure 4, the heating element 12 includes a plurality of heating contact portions 50 and a recess 51.

[0034] The heating contact portion 50 is a convex portion that protrudes downward with height relative to the bottom of the recess 51, and is a convex ridge that extends in a direction perpendicular to the extension direction (short side direction B1) of the heating member 12, and has a rectangular shape when viewed from the front. The heating contact portion 50 is the part that comes into contact with the connecting wiring member 111 of the solar cell 110 when the operating handle portion 10 is operated, and heats and melts the solder layer 156 on the surface of the connecting wiring member 111. As shown in Figure 4(a), the heating contact portions 50 are arranged at intervals along the longitudinal direction A1 of the heating member 12, and in this embodiment, they are arranged at equal intervals. The width D1 of the heating contact area 50 shown in Figure 4(b) is preferably 10 mm or more and 15 mm or less. Within this range, it is possible to ensure sufficient adhesive strength through the solder layer 156 while relieving the stress on the connecting wiring member 111 during bonding.

[0035] The recessed portion 51 is a part that is recessed with depth on the upper side relative to the heating contact portion 50, and has a rectangular shape when viewed from the front. The recess 51 is provided at the boundary of the heating contact portion 50 and is a portion that demarcates adjacent heating contact portions 50. It is a groove that extends in a direction perpendicular to the extension direction of the heating member 12 (short side direction B1). The recesses 51 are arranged at intervals along the longitudinal direction A1 of the heating element 12, and in this embodiment, they are arranged at equal intervals. The width D2 of the recess 51 shown in Figure 4(b) is preferably 1.5 mm or more and 3.5 mm or less.

[0036] (Solar module 100) As shown in Figure 5(a), the solar cell module 100 comprises one or more solar cell strings 101 (101a to 101f), lead-out wiring members 102 (102a to 102c), a first protective member 103, a second protective member 105, a first sealing sheet 106, and a second sealing sheet 107. As shown in Figure 5(b), the solar cell string 101 comprises a plurality of solar cells 110, a connecting wiring member 111, and a conductive adhesive 112.

[0037] (Solar cell 110) The solar cell 110 comprises a photoelectric conversion substrate 120, a first collector electrode 121, and a second collector electrode 122.

[0038] As shown in Figure 5, the photoelectric conversion substrate 120 is a plate-shaped substrate having a first main surface 125 and a second main surface 126. The first transparent electrode layer 131 is laminated on the first main surface 125 side of the photoelectric conversion section 130, and the second transparent electrode layer 132 is laminated on the second main surface 126 side, making it a transparent conductive substrate.

[0039] The photoelectric conversion unit 130 has a PN junction and is the part that converts light energy into electrical energy.

[0040] The transparent electrode layers 131 and 132 are transparent conductive layers that possess transparency and conductivity, and specifically, they are transparent conductive oxide layers composed of transparent conductive oxides such as indium tin oxide (ITO) and tungsten-doped indium oxide (IWO).

[0041] The first collecting electrode 121 is paired with the second collecting electrode 122 and, together with the second collecting electrode 122, is an extraction electrode that extracts the electrical energy photoelectrically converted by the photoelectric conversion substrate 120 from the photoelectric conversion substrate 120. As shown in Figure 9, the collector electrodes 121 and 122 are partially formed on both main surfaces 125 and 126 of the photoelectric conversion substrate 120, and are mainly composed of metal electrode layers. The metal electrode layer is a metal layer that has higher conductivity than the transparent electrode layers 131 and 132. The metal electrode layer is not particularly limited as long as it has a higher conductivity than the transparent electrode layers 131 and 132, but can be made of, for example, gold, silver, copper, platinum, aluminum, nickel, palladium, etc.

[0042] Furthermore, as shown in Figure 9(a), the first collecting electrode 121 is composed of a first busbar electrode portion 150a and a first finger electrode portion 151a when the photoelectric conversion substrate 120 is viewed from the first main surface 125 side. As shown in Figure 9(b), the second collecting electrode 122 is composed of a second busbar electrode portion 150b and a second finger electrode portion 151b when the photoelectric conversion substrate 120 is viewed from the second main surface 126 side. The busbar electrode sections 150a and 150b have a width in the vertical direction Y (parallel arrangement direction) and extend in the horizontal direction X. In other words, it is preferable that at least a portion of the busbar electrode portions 150a and 150b extends along the lateral edge, and the maximum distance to the nearest lateral edge (one side) is 160 mm or less. Furthermore, it is preferable that the maximum distance between the busbar electrode portions 150a and 150b and the nearest adjacent transverse side is between 1 / 20 and 1 / 3 of the length of that transverse side. Within these ranges, the busbar electrode sections 150a and 150b are located towards the edges, so the connecting wiring member 111 is less likely to obstruct light reception by the solar cell 110.

[0043] As shown in Figure 9, the finger electrode portions 151a and 151b are parts that extend in a comb-like manner from the middle portion of the busbar electrode portions 150a and 150b. The finger electrode portions 151a and 151b extend in a direction intersecting the extension direction (lateral direction X) of the busbar electrode portions 150a and 150b. In this embodiment, they extend in a direction perpendicular to the extension direction (vertical direction Y) of the busbar electrode portions 150a and 150b. That is, the finger electrode portions 151a and 151b have a width in the lateral direction X and extend in the vertical direction Y.

[0044] (Connecting wiring member 111) The connecting wiring component 111 is an extraction wiring that extracts electricity from the solar cell 110. The connecting wiring member 111 is a ladder-shaped wiring extending in the lateral direction X, as shown in Figure 7, and is a solder-coated wiring in which a solder layer 156 is coated on the surface of a metal core 155, as shown in Figure 8(b). As shown in Figures 6 and 7, the connecting wiring member 111 includes a first wiring section 160, a second wiring section 161, and connecting wiring sections 162a to 162e. The first wiring section 160 extends in the direction of extension (lateral direction X) of most of the busbar electrode sections 150a and 150b. The first wiring section 160 comprises base sections 163a to 163f and a plurality of expansion sections 165a to 165e, as shown in Figure 8(a). The base portions 163a to 163f are connected to the busbar electrode portion 150a (150b) by a solder layer 156. The expanded portions 165a to 165e are areas that have expanded relative to the base portions 163a to 163f due to thermal expansion, and are raised portions that are elevated relative to the base portions 163a to 163f. The expanded portions 165a to 165e are raised from the busbar electrode portions 150a (150b), and a space is formed between them and the busbar electrode portions 150a (150b). The density of the expanded sections 165a to 165e is lower than that of the base sections 163a to 163f.

[0045] As shown in Figure 7, the second wiring section 161 extends parallel to the first wiring section 160 with a gap between them in the direction in which the solar cells 110 are arranged side by side (the direction in which the solar cell string 101 extends, the vertical direction Y). The connecting wiring sections 162a to 162e extend from the first wiring section 160, crossing over each other, and connect the intermediate section of the first wiring section 160 with the intermediate section of the second wiring section 161. Each connection wiring section 162a to 162e extends in the direction of parallel arrangement of the solar cells 110 (vertical direction Y) and is parallel to the others.

[0046] (Conductive adhesive 112) The conductive adhesive 112 has both conductivity and adhesive properties, and is used to bond the busbar electrode portions 150a and 150b of adjacent solar cells 110, 110, as shown in Figure 5(b). The conductive adhesive 112 is not particularly limited as long as it has conductivity and adhesive properties. For example, a resin containing metal fine particles or a metal paste can be used as the conductive adhesive 112.

[0047] (Outlet wiring component 102) The lead-out wiring members 102 (102a to 102c) are connected to the connecting wiring member 111 and are wires that draw power from the solar cell string 101 to the outside. As shown in Figure 5(a), the lead wiring members 102a and 102b have one end connected to the connecting wiring member 111, and the end opposite to the connecting wiring member 111 is connected to a terminal box (not shown). The lead wiring member 102c is provided spanning the connecting wiring members 111, 111 and electrically connects the connecting wiring members 111, 111 to each other. In other words, the lead-out wiring member 102c electrically connects each solar cell string 101a~101c (101d~101f) in parallel, and electrically connects solar cell strings 101a~101c and solar cell strings 101d~101f in series.

[0048] (Protective members 103, 105) As shown in Figure 5(b), the first protective member 103 constitutes the first main surface 170 of the solar cell module 100 and is a member that protects the first main surface 170 side of each solar cell string 101a to 101f. The first protective member 103 is a transparent protective material, and can be, for example, a glass substrate or a transparent resin film. The second protective member 105 constitutes the second main surface 171 of the solar cell module 100 and is a member that protects the second main surface 171 side of the solar cell strings 101a to 101f. The second protective member 105 can be a transparent protective material such as a glass substrate or a transparent resin film, a light-reflective protective material such as a metal film, or a light-absorbing protective material such as a black resin film.

[0049] (Sealing sheets 106, 107) The sealing sheets 106 and 107 are transparent sealing sheets that have transparency and sealing properties, and are used to bond the protective members 103 and 105 between the solar cell strings 101 (101a to 101f). The sealing sheets 106 and 107 are not particularly limited as long as they have transparency, sealing properties, and adhesive properties. For example, transparent resin sheets such as PET (polyethylene terephthalate) sheets, olefin sheets, and EVA (ethylene vinyl acetate) sheets can be used as sealing sheets 106 and 107.

[0050] Here, we will explain the positional relationships of each part of the solar cell module 100.

[0051] As shown in Figure 5(a), the solar cell module 100 has multiple solar cell strings 101a to 101f arranged in a horizontal direction X, with solar cell strings 101a to 101c and solar cell strings 101d to 101f reversed in orientation. As shown in Figure 5(b), the solar cell strings 101a to 101f are sandwiched between sealing sheets 106 and 107, and further sandwiched from the outside of the sealing sheets 106 and 107 by protective members 103 and 105. When viewed from above, the solar cell string 101 has an overlapping portion between adjacent solar cells 110, 110 in the vertical direction Y, with the first busbar electrode portion 150a of one solar cell 110 and the second busbar electrode portion 150b of the other solar cell 110 located in this overlapping portion. The first busbar electrode portion 150a and the second busbar electrode portion 150b are bonded together by a conductive adhesive 112. As shown in Figure 8(b), the solar cells 110, 110 located at the ends in the vertical direction Y have the first wiring sections 160, 160 of the connecting wiring members 111, 111 connected to the busbar electrode sections 150a, 150b, respectively. The second wiring section 161 of the connecting wiring member 111 is connected to the lead wiring member 102.

[0052] Next, a description of the manufacturing method for the solar cell module 100 of this embodiment will be provided.

[0053] The manufacturing method for the solar cell module 100 of this embodiment mainly includes a solar cell formation step, a wiring connection step, a string formation step, a lead-out wiring step, and a sealing step.

[0054] First, multiple solar cells 110 are formed (solar cell formation process).

[0055] Next, we move on to the wiring connection process, which is one of the main features of this embodiment, and involves connecting the connecting wiring member 111 to the solar cell 110.

[0056] In the wiring connection process, first, the solar cell 110 is placed on the mounting section 20 of the base section 2 of the soldering device 1.

[0057] At this time, the solar cell 110 is positioned such that the busbar electrode portion 150a (150b) of the solar cell 110 is located directly below the heating element 12, as shown in Figure 11(a).

[0058] Next, if necessary, the angle of the heating element 12 relative to the solar cell 110 is adjusted by the angle adjustment units 25 and 37.

[0059] At this time, the angle of the heating element 12 is adjusted so that its extension direction (longitudinal direction A1) is parallel to the extension direction (lateral direction X) of the busbar electrode portion 150a (150b) of the solar cell 110.

[0060] Once the heating element 12 is positioned so that the busbar electrode portion 150a (150b) of the solar cell 110 is positioned on the vertical projection plane, the operator lowers the operating handle portion 10 downwards against the biasing force of the biasing member 6, as shown in Figure 10. As a result, the link mechanism 32 lowers the heating element 12, and as shown in Figure 11(b), each heating contact portion 50 of the heating element 12 comes into contact with the connecting wiring member 111, melting the solder layer 156 on the surface of the connecting wiring member 111, and bonding the busbar electrode portion 150a (150b) of the solar cell 110 and the connecting wiring member 111 by the solder layer 156 (wiring connection process).

[0061] The temperature of the heated contact area 50 at this time is a temperature that can melt the solder layer 156, preferably 150°C to 300°C, and more preferably 200°C to 250°C. When the operating handle portion 10 is operated, the pressure exerted on the solar cell 110 by the heated contact portion 50 is preferably 30N or more and 40N or less. The heating time is preferably between 1 second and 5 seconds. The heating time may differ between the front and back sides of the solar cell 110.

[0062] Furthermore, at this time, the busbar electrode portion 150a (150b) of the solar cell 110 has portions that are in contact with each heating contact portion 50 and portions that are not in contact. This forms an adhesive region 180 where the busbar electrode portion 150a (150b) and the connecting wiring member 111 are bonded by the solder layer 156, and a non-adhesive region 181 where the busbar electrode portion 150a (150b) and the connecting wiring member 111 are not bonded by the solder layer 156. Then, as shown in Figure 12, multiple expanded portions 165a to 165e are formed on the connecting wiring member 111 in the non-adhesive region 181, bulging in a direction away from the solar cell 110.

[0063] Once the wiring connection process is complete and the connecting wiring members 111 are bonded to the solar cells 110, the solar cells 110 are arranged in the vertical direction Y, and the busbar electrode portions 150a and 150b of adjacent solar cells 110 are connected with conductive adhesive 112, thereby electrically connecting each solar cell 110 in series and forming a solar cell string 101 (string formation process).

[0064] Next, the solar cell strings 101 are arranged in a horizontal X direction, the lead wiring members 102 are attached to the second wiring section 161 with a conductive adhesive such as solder, and the lead wiring members 102 are connected to the connecting wiring members 111 (lead wiring process).

[0065] Next, the solar cell string 101 to which the lead-out wiring member 102 is connected is sandwiched between sealing sheets 106, 107 and protective members 103, 105, and each solar cell 110 is sealed by heat compression (sealing process).

[0066] Afterward, terminal boxes and other components are attached as needed to complete the solar cell module 100.

[0067] According to the soldering apparatus 1 of this embodiment, the heating element 12 extends in the longitudinal direction A1, and the connecting wiring member 111 can be soldered at once, making it easy to control the amount of heat applied to the connecting wiring member 111 and the solar cell 110.

[0068] According to the soldering apparatus 1 of this embodiment, since a recess 51 is formed between the heating contact portions 50 of the heating element 12, even if the connecting wiring member 111 expands due to the heating of the solder layer 156, the connecting wiring member 111 escapes into the recess 51. This makes it less likely for the connecting wiring member 111 to lift at the adhesive portion, and can suppress poor adhesion of the solder layer 156 due to the thermal expansion of the connecting wiring member 111 when the solder layer 156 is heated.

[0069] According to the soldering apparatus 1 of this embodiment, the heating contact section 50 can be raised and lowered while remaining in a horizontal position, allowing for uniform heating and making it easier to control the amount of heat applied to the solar cell 110 and the connecting wiring member 111.

[0070] According to the soldering apparatus 1 of this embodiment, since the heating member 12 is biased upward by the biasing member 6, it is easy to adjust the pressing force applied by the heating contact portion 50 to the solar cell 110, and it is possible to prevent excessive pressure from being applied to the solar cell 110. As a result, the occurrence of cracks in the solar cell 110 can be suppressed.

[0071] Thus, according to the soldering apparatus 1 of this embodiment, defects such as non-adhesion of the solder layer 156 depending on the heating temperature, interfacial fracture between the solder layer 156 and the busbar electrode portion 150a (150b) depending on the amount of heat, and cell cracking depending on the pressure from the heated contact portion 50 can be suppressed. As a result, a decrease in the power generation of the solar cell module 100 and disconnection due to load fluctuations can be suppressed, and a high-quality solar cell module 100 can be manufactured.

[0072] In the solar cell module 100 of this embodiment, the connecting wiring member 111 is bonded to the busbar electrode portion 150a (150b) at multiple locations by solder layers 156, so even if there is a defect in the adhesion of a part of the solder layer 156, a conductive path can be secured by the other parts.

[0073] In the embodiment described above, the recess 51 was rectangular when viewed from the front, but the present invention is not limited thereto. The shape of the recess 51 may be a polygon such as a triangle, pentagon, or hexagon when viewed from the front, as shown in Figure 13(a), or it may be a semicircle or semiellipse, as shown in Figure 13(b).

[0074] In the embodiment described above, the recesses 51 were arranged side by side with spacing only in the lateral direction X, but the present invention is not limited thereto. The recesses 51 may also be arranged side by side with spacing in the vertical direction Y.

[0075] In the embodiments described above, the wiring connection process was performed before the string formation process, but the present invention is not limited thereto. The wiring connection process may be performed after the string formation process or after the lead-out wiring process.

[0076] In the embodiment described above, a solder layer 156 provided on the surface of the connecting wiring member 111 was used as the solder to bond the busbar electrode portions 150a and 150b to the connecting wiring member 111, but the present invention is not limited thereto. Solder independent of the connecting wiring member 111 may also be used. The type of solder is not particularly limited, and for example, solder paste or solder balls can be used.

[0077] In the embodiment described above, the heating contact portion 50 was brought into direct contact with the connecting wiring member 111 to melt a portion of the solder layer 156 on the surface of the connecting wiring member 111. However, the present invention is not limited thereto. The heating contact portion 50 may be brought close to the solder layer 156 on the surface of the connecting wiring member 111 to melt the solder layer 156, or the heating contact portion 50 may be used indirectly to melt the solder layer 156 on the surface of the connecting wiring member 111 via a heat transfer element.

[0078] In the embodiments described above, the components can be freely substituted or added between each embodiment, as long as they fall within the technical scope of the present invention. [Explanation of Symbols]

[0079] 1. Soldering device 6. Biasing member 10. Operating handle section (operating section) 12 Heating element 50 Heating contact area 51 Recess 100 solar modules 110 Solar Cells (Solar Cells) 111 Connecting wiring components (wiring components) 150a First busbar electrode section (busbar electrode section) 150b Second busbar electrode section (busbar electrode section) 156 Solder layer (solder) 165a~165e Expansion section 180 Adhesive area 181 Non-adhesive area

Claims

1. A soldering device that melts solder to bond the busbar electrode portion of a solar cell to a wiring component, It has a long heating element and a lifting mechanism that raises and lowers the heating element vertically. The heating element has a plurality of heating contact portions and a plurality of recesses, The plurality of recesses are formed at intervals along the longitudinal direction of the heating member. The plurality of heating contact portions are capable of heating the solder and are separated by the plurality of recesses. A soldering device that, when bonding the wiring member to the busbar electrode portion, brings the heating contact portion close to or in contact with the busbar electrode portion, thereby causing the wiring member to expand in a direction away from the solar cell and forming multiple bulging portions that float away from the busbar electrode portion.

2. The soldering apparatus according to claim 1, wherein the distance between adjacent heating contact portions in the longitudinal direction of the heating member is 1.5 mm or more and 3.5 mm or less.

3. The soldering apparatus according to claim 1 or 2, wherein the plurality of heating contact portions are arranged at equal intervals in the longitudinal direction.

4. It has an operating section, The lifting mechanism allows the heating element to be raised and lowered by operating the operating section. The soldering apparatus according to any one of claims 1 to 3, wherein the lifting mechanism comprises a biasing member that biases the heating member in the direction of upward movement.

5. Having a plurality of solar cells, a wiring member, and a solder layer, The aforementioned solar cells are arranged in parallel in the parallel direction and electrically connected in series to form a solar cell string. The solar cells located at the ends in the parallel arrangement direction have busbar electrode portions, The busbar electrode portion extends in a predetermined direction different from the parallel arrangement direction when viewed from above, The wiring member has a first wiring section and a connecting wiring section that intersects with the first wiring section, and when viewed from above, the first wiring section overlaps with the busbar electrode section. The busbar electrode portion and the wiring member have an adhesive region where they are bonded together by the solder layer, and an unadhesive region where they are not bonded together by the solder layer. The first wiring section has a plurality of expanded portions in the non-adhesive region that bulge in a direction away from the solar cell, The plurality of expansion portions are arranged at intervals in the predetermined direction in a solar cell module.

6. The aforementioned solar cell has one side, The solar cell module according to claim 5, wherein the busbar electrode portion is provided along one side and the maximum distance from the one side is 160 mm or less.

7. A method for manufacturing a solar cell module, comprising bonding a wiring member to the busbar electrode portion of a solar cell using a soldering apparatus according to any one of claims 1 to 4, A process of placing a wiring member, whose surface is covered with a solder layer, onto the busbar electrode portion of a solar cell, A method for manufacturing a solar cell module, comprising the step of bringing the heating contact portion close to or in contact with the wiring member to melt a portion of the solder layer on the surface of the wiring member.

Images