JP2013084726A - Solar cell bus bar wiring apparatus and wiring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent soldering defects due to plastic deformation caused by extension of a ribbon and reliably perform soldering with high positioning accuracy without causing misalignment.SOLUTION: A solar cell bus bar wiring apparatus includes: a ribbon supply part 10 supplying a ribbon 12; a chuck 35 holding the ribbon; a holding part 30 having a cutter 31 for cutting; a driving part 33 which moves the holding part and applies tensile force to the ribbon during soldering; a chuck 74 holding the ribbon; a soldering part 70 having a soldering tool 73 which solders the ribbon on a solar cell; a guide part 50 restricting misalignment of the ribbon during the soldering; and a driving part 72 moving the guide part and the soldering part. The driving part 72 moves the soldering part and the guide part along a predetermined direction thereby soldering the ribbon on a surface of the solar cell.

Description

  The present invention relates to a bus bar wiring device and a wiring method for solar cells, and more particularly to a device and method suitable for soldering a ribbon to a thin film solar cell.

  As a power generation system using natural energy, solar power generation has become widespread. A solar cell is the smallest unit of a photovoltaic power generation system and is an element that converts solar energy into electric power. Among them, a crystalline silicon solar cell made of a monocrystalline or polycrystalline silicon substrate is the most common, but in recent years, a thin film solar cell has attracted attention.

As an example of a thin film solar cell, a structure of a solar cell using amorphous silicon is shown in FIG. In this solar cell, when one surface of a substrate 101 made of glass, plastic, or the like is used as a light receiving surface, an SnO ₂ transparent electrode 102, a p-type amorphous silicon layer 103, and an i-type as a light absorption layer are formed on the other surface. An amorphous silicon layer 104 and an n-type amorphous silicon layer 105 are sequentially deposited, and an aluminum electrode 106 is formed.

  Alternatively, there are CIGS-based, CIS-based, chalcopyrite-based solar cells using a light absorption layer made of copper, indium, selenium, gallium or the like instead of silicon, as shown in FIG. On a substrate 111 made of plastic, metal foil or the like, a back electrode 112 made of Mo or the like, a light absorption layer 113 made of a p-type semiconductor layer such as CIGS, CIGSS, or CIS, a buffer layer 114 made of ZnS, InS, or the like, ZnO, etc. The transparent electrode 115 is formed in order from the n-type semiconductor layer 115, the surface of which is a light receiving surface.

  FIG. 18 shows a planar configuration of the amorphous silicon solar cell module 1A. This solar cell module 1A has a structure in which a plurality of photoelectric conversion cells 2 are electrically connected in series on a substrate made of glass or the like. Each photoelectric conversion cell 2 has an elongated rectangular shape along the long side of the solar cell module 1A, and one of the photoelectric conversion cells 2a or 2b at both ends in the short direction of the solar cell module 1A is a positive electrode, and the other The photoelectric conversion cell 2b or 2a becomes a negative electrode.

  In order to take out electric power from the solar cell module 1A, the lead 6 is wired on the back surface opposite to the light receiving surface of the solar cell module 1A after the insulating tape 5 is pasted to the middle of the photoelectric conversion cells 2a and 2b. Further, the bus bars 3 and 4 are wired to the photoelectric conversion cells 2a and 2b, respectively, and the lead 6 is connected to the terminal box 7 for power output.

  The bus bar wiring is a technique in which a ribbon is connected to each of the positive and negative photoelectric conversion cells of the solar cell module 1A and an electrode including such bus bars 3 and 4 is formed in order to extract electric power from the solar cell module 1A. is there.

  FIG. 19 shows a planar configuration of the CIGS solar cell module 1B. Similarly to the amorphous silicon solar cell module 1A shown in FIG. 18, the solar cell module 1B has a structure in which a plurality of photoelectric conversion cells 2 are electrically connected in series on a substrate made of glass or the like. Each photoelectric conversion cell 2 has an elongated rectangular shape along the long side of the solar cell module 1B, and one of the photoelectric conversion cells 2a or 2b at both ends in the short direction of the solar cell module 1B is the positive electrode, and the other The cell 2b or 2a becomes a negative electrode.

  In order to take out electric power from the solar cell module 1B, the bus bars 3 and 4 are wired to the photoelectric conversion cells 2a and 2b on the light receiving surface of the solar cell module 1B. Furthermore, the lead 5 is wired to the back side of the substrate through the through hole 6 provided at the end of the substrate, and connected to the terminal box 7 for power output.

  In any type of solar cell module, in order to obtain high reliability by reliably extracting power from the solar cell, the ribbon is arranged with high positioning accuracy without any deviation from the positive and negative photoelectric conversion cells. However, it is necessary to securely solder.

  However, the ribbon is usually drawn out and used as necessary from the state wound around a bobbin or the like. For this reason, the ribbon has a curl and has a planar bend and twist. As a result, there are problems such as insufficient adhesion of the ribbon to the substrate of the solar cell module and misalignment. Therefore, conventionally, it has been common to perform soldering after applying tension to the ribbon to cause plastic deformation.

  The following patent documents exist as a technique for disposing a ribbon (elongated conductor) on a conventional solar cell.

JP 2010-0697968 A

  As described above, in the prior art, there is a technique in which a ribbon is plastically deformed to be linear and then adhered to a substrate.

  However, if the ribbon is stretched for plastic deformation, the welding area may be reduced, resulting in insufficient soldering or cracking. Further, when the ribbon is hardened by plastic deformation, there is a possibility that the tension increases due to shrinkage during cooling and peeling occurs.

  In the method and apparatus for attaching an elongated conductor described in Patent Document 1, the elongated conductor is stretched with a tension slightly exceeding the yield point at which the elongated conductor starts plastic deformation, causing minimal plastic deformation and removing curl. I am going to do that. However, it is technically difficult to stretch the elongated conductor with a tension slightly exceeding the yield point, and a mechanism for monitoring so as not to exceed the limit of the tension is necessary, and an increase in cost is inevitable.

  SUMMARY OF THE INVENTION In view of the above circumstances, the present invention eliminates a soldering failure caused by plastic deformation due to the elongation of a ribbon, and can securely solder a ribbon with high positional accuracy and without misalignment. The purpose is to provide.

The bus bar wiring device for solar cells of the present invention,
A gripping part having a chuck for gripping the supplied ribbon;
A first drive unit that applies a predetermined tension to the ribbon by a predetermined torque when soldering;
A soldering part having a soldering tool for soldering the ribbon on the surface of the solar cell;
A guide portion for restricting positional deviation of the ribbon during soldering;
A second drive unit for moving the soldering unit and the guide unit along a predetermined direction;
A control unit for controlling operations of the gripping unit, the first driving unit, the soldering unit, the guide unit, and the second driving unit;
With control of the control unit,
The ribbon is soldered on the surface of the solar cell by the second driving unit moving the soldering unit and the guide unit along the predetermined direction.

The solar cell bus bar wiring method of the present invention,
A gripping part having a chuck for gripping the supplied ribbon;
A first drive unit that applies a predetermined tension to the ribbon by a predetermined torque when soldering;
A soldering part having a soldering tool for soldering the ribbon on the surface of the solar cell;
A guide portion for restricting positional deviation of the ribbon during soldering;
A second drive unit for moving the soldering unit and the guide unit along a predetermined direction;
A solar cell bus bar wiring device comprising the gripping unit, the first driving unit, the soldering unit, the guide unit, and a control unit for controlling the operations of the second driving unit. A method of wiring a bus bar,
The ribbon is soldered onto the surface of the solar cell by the second driving unit moving the soldering unit and the guide unit along the predetermined direction under the control of the control unit. Features.

  According to the bus bar wiring device and wiring method for solar cells of the present invention, reliable soldering is performed by soldering without misalignment without stretching the ribbon with tension that causes plastic deformation as in the prior art. It is possible to reliably extract electric power from the solar cell.

It is a front view which shows the schematic structure of the whole bus bar wiring apparatus of the solar cell by embodiment of this invention. It is a front view which shows the structure of the ribbon supply part in the bus-bar wiring apparatus of the solar cell by the same embodiment. It is the top view and front view which show the structure of the holding part in the bus-bar wiring apparatus of the solar cell by the same embodiment. It is the front view, right view, and left view of the guide part and soldering part in the bus-bar wiring device of the solar cell by the same embodiment. It is explanatory drawing which showed the principal part for every process of the bus-bar wiring method of the solar cell by embodiment of this invention using the bus-bar wiring apparatus of solar cell by the embodiment. It is explanatory drawing which showed the principal part for every process of the bus-bar wiring method of the solar cell by embodiment of this invention using the bus-bar wiring apparatus of solar cell by the embodiment. It is explanatory drawing which showed the principal part for every process of the bus-bar wiring method of the solar cell by embodiment of this invention using the bus-bar wiring apparatus of solar cell by the embodiment. It is explanatory drawing which showed the principal part for every process of the bus-bar wiring method of the solar cell by embodiment of this invention using the bus-bar wiring apparatus of solar cell by the embodiment. It is explanatory drawing which showed the principal part for every process of the bus-bar wiring method of the solar cell by embodiment of this invention using the bus-bar wiring apparatus of solar cell by the embodiment. It is explanatory drawing which showed the principal part for every process of the bus-bar wiring method of the solar cell by embodiment of this invention using the bus-bar wiring apparatus of solar cell by the embodiment. It is explanatory drawing which showed the principal part for every process of the bus-bar wiring method of the solar cell by embodiment of this invention using the bus-bar wiring apparatus of solar cell by the embodiment. It is explanatory drawing which showed the principal part for every process of the bus-bar wiring method of the solar cell by embodiment of this invention using the bus-bar wiring apparatus of solar cell by the embodiment. It is an enlarged view which expands and shows the part enclosed with the dotted line in FIG. It is explanatory drawing which showed the principal part for every process of the bus-bar wiring method of the solar cell by embodiment of this invention using the bus-bar wiring apparatus of solar cell by the embodiment. It is explanatory drawing which showed the principal part for every process of the bus-bar wiring method of the solar cell by embodiment of this invention using the bus-bar wiring apparatus of solar cell by the embodiment. It is the longitudinal cross-sectional view which showed the structure of the amorphous silicon solar cell as an example of the object of the bus-bar wiring in this invention. It is the longitudinal cross-sectional view which showed the structure of the CIGS type | system | group solar cell as an example of the object of the bus-bar wiring in this invention. It is the top view which showed the structure which takes out electric power from an amorphous silicon solar cell module. It is the top view which showed the structure which takes out electric power from a CIGS type | system | group solar cell module.

  Hereinafter, a bus bar wiring device according to an embodiment of the present invention and a bus bar wiring method using the bus bar wiring device will be described with reference to the drawings.

  First, a preparation process performed before bus bar wiring will be described. In many solar cells, the substrate is made of a material that is difficult to solder, such as glass, plastic, or aluminum. For this reason, before soldering a ribbon, it is necessary to form the contact bonding layer which has electroconductivity in the photoelectric conversion cell of a positive electrode and a negative electrode. For example, a preliminary solder such as indium is soldered on the surface of the photoelectric conversion cell, or a conductive paste is applied.

  The ribbon is formed by coating a conductive material made of pure copper with solder (Sn—Pb) or lead-free type solder (Sn—Ag—Cu), and has a width of 1 to 5 mm and a thickness of 100 to 200 μm, for example. Moreover, a solar cell module has various dimensions, such as 600 mm x 1600 mm, 1100 mm x 1400 mm, and each photoelectric conversion cell has a width | variety of about 5-6 mm, for example.

  Hereinafter, a specific configuration of the solar cell bus bar wiring device according to the present embodiment will be described in detail with reference to the drawings. The bus bar is connected to both the positive and negative photoelectric conversion cells of the substrate of the solar cell, but since the connection method is the same, the case of connecting to either one will be described as an example. .

  In FIG. 1, the structure of the whole bus-bar wiring apparatus of a solar cell is shown schematically. The bus bar wiring apparatus includes a ribbon supply unit 10, a gripping unit 30, a guide unit 50, and a soldering unit 70 as main components. The ribbon supply unit 10, the gripping unit 30, the guide unit 50, and the soldering unit 70 are controlled by the central control unit 80.

  On the surfaces of the positive and negative photoelectric conversion cells of the solar cell 1, although not shown, preliminary solder is applied in advance or a conductive paste is applied.

  FIG. 2 shows a detailed configuration of the ribbon supply unit 10. The ribbon supply unit 10 includes a bobbin 13, a roller 11, a step roller 14, guide rollers 15 and 16, and a chuck A 17. The ribbon 12 is wound around the bobbin 13, and the fed ribbon 12 is drawn around the roller 11, the step roller 14, the guide rollers 15 and 16 in order, and is gripped or released by the chuck A 17.

  When the ribbon 12 is pulled out from the bobbin 13, the step roller 14 moves up and down by its own weight, so that an appropriate second tension is applied to the ribbon 12, and the ribbon 12 is pulled out without loosening. The central controller 80 controls the gripping / opening of the chuck A 17 and the operation of a servo motor (not shown) that drives the bobbin 13.

  FIG. 3A shows a configuration of the grip portion 30 viewed from the top, and FIG. 3B shows a configuration viewed from the front. The grip portion 30 includes a cutter 31, an LM guide 32, a servo motor 33, a block 34, and a chuck B 35. When the servo motor 33 rotates forward or backward, the chuck B 35 and the cutter 31 connected to each other by the block 34 move in the direction a indicated by the arrow in the drawing. As will be described later, an appropriate first tension is applied to the ribbon 12 by rotating the servo motor 33 with a predetermined torque during soldering. The central control unit 80 controls the cutting / release of the cutter 31, the grip / release of the chuck B 35, a mechanism such as a cylinder or a motor (not shown) that drives the LM guide 32, and the operation of the servo motor 33.

  FIG. 4B shows the configuration of the guide unit 50 and the soldering unit 70 viewed from the front, FIG. 4A shows the configuration viewed from the left side, and FIG. 4C shows the configuration viewed from the right side.

  The guide unit 50 includes guides 51 and 52 and a pressing roller 53. The LM guide 55 to which the guide 52 and the pressing roller 53 are connected is movable in the c direction indicated by an arrow in the figure under the control of the central control unit 80 by a mechanism such as a cylinder or a motor (not shown).

  The soldering unit 70 includes a soldering tool 73 and a chuck C74. The soldering tool 73 can be moved by the servo motor 71 in the d direction indicated by the arrow in the figure. The LM guides 56 and 57 to which the chuck C 74 is connected can be moved in the e and f directions indicated by arrows in the drawing under the control of the central control unit 80 by a mechanism such as a cylinder or a motor (not shown). is there. The central controller 80 controls the soldering of the soldering tool 73, the gripping / releasing of the chuck C74, and the operation of the servomotor 71.

  The guide portion 50 and the soldering portion 70 are assembled to the plate 58, and the whole plate 58 can be moved in the b direction indicated by the arrow in the figure by driving a servo motor 72 provided on the back surface of the plate 58. is there. The operation of the servo motor 72 is controlled by the central controller 80.

  As a means for moving in these a, b, c, d, e, and f directions, a mechanism different from the above mechanism may be used.

  A bus bar wiring method according to the present embodiment in which wiring processing is performed using a solar cell bus bar wiring device having such a configuration will be described with reference to FIGS. Each operation is controlled by the central control unit 80.

  First, as shown in FIG. 5, the guide part 50 and the soldering part 70 which are assembled to the plate 58 and can be moved at the same time are moved away from the A direction indicated by the arrow in FIG. Move toward 10

  As shown in FIG. 6, the end of the ribbon 12 is gripped by the chuck C 74, and the chuck A 17 is released.

  As shown in FIG. 7, the guide portion 50 and the soldering portion 70 move in the B direction indicated by the arrow in the drawing, that is, on the surface of the solar cell 1 by the required length of the ribbon 12.

  As shown in FIG. 8, the ribbon 12 is gripped by the chuck A 17, the ribbon 12 is gripped by the chuck B 35, and the ribbon 12 is cut by the cutter 31 positioned therebetween.

  The chuck B 35 and the cutter 31 are provided with a moving mechanism such as the LM guide 32 shown in FIG. 3 in order to avoid interference with the guide unit 50 and the soldering unit 70, and the movement of the plate 58. It is good also as a mechanism movable in the direction orthogonal to.

  As shown in FIG. 9, the chuck 31 is opened, and the chuck B 35 and the guide unit 50 are moved to the position where the ribbon 12 is soldered on the portion of the solar cell 1 where the preliminary solder or conductive paste is formed. The soldering portion 70 moves in the B direction indicated by the arrow in the drawing. The chuck A 17 waits in a state where it is held until the next ribbon 12 is supplied.

  As shown in FIG. 10, the chuck C 74 is lowered by the LM guide 56. As a result, the ribbon 12 is fitted into the groove of the guide 51 in the guide portion 50.

  As shown in FIG. 11, the guide 52 and the pressing roller 53 in the guide portion 50 are lowered by the LM guide 55 and stopped at a position where the pressing roller 53 contacts the ribbon 12. As a result, the ribbon 12 is fitted into the groove of the guide 52, and at the same time, the chuck C74 is released.

  12 and FIG. 13 showing an enlarged portion surrounded by a dotted line in FIG. 12, the chuck C 74 is moved laterally by the LM guide 57 to a position where it does not interfere with the soldering tool 73. The LM guide 56 ascends to the next ribbon gripping height. Thereafter, the soldering tool 73 is lowered to the soldering position. As described above, the ribbon 12 is fitted in the groove indicated by the dotted line in the guides 51 and 52.

  As shown in FIG. 14, in a state where the ribbon 12 is gripped at a fixed position by the chuck B 35, the guide unit 50 and the soldering unit 70 are moved to the A direction indicated by the arrow in FIG. Move in the direction of approach.

  Here, the servo motor 33 in the gripping portion 30 moves the gripping portion 30 with a predetermined torque so that the ribbon 12 being soldered is applied with a first tension having a degree of straightness on the solar cell 1. Drive in direction A. The torque is desirably set in advance to a value that does not cause plastic deformation of the ribbon 12 according to the material, hardness, width, thickness, soldering conditions, and the like of the ribbon.

  Further, the guide 51, the guide 52, the pressing roller 53, and the tip of the soldering tool 73 in the guide portion 50 are arranged with the center line aligned as shown by the dotted line g in FIG. For this reason, the pressing roller 53 and the soldering portion 70 move in a state where the ribbon 12 is fitted in the guide grooves of the guides 51 and 52, so that the soldering is performed while restricting the displacement of the ribbon 12 to the left and right. be able to. As a result, it is possible to prevent the bus bar from being displaced without using a previously stretched ribbon.

  As shown in FIG. 15, when the guide 51 of the guide portion 50 is close to the chuck B 35, the chuck B 35 is released and returned to the standby position, and when the soldering portion 70 reaches the end of the ribbon 12. The guide 52 and the pressing roller 53 of the guide part 50 are raised by the LM guide 55, and the soldering part 70 is raised by the servo motor 71. Thereby, the wiring of the bus bar is completed.

  Note that a material that is difficult to solder is used for the substrate of the solar cell, such as glass, plastic, and aluminum. For this reason, it is desirable to perform soldering in the soldering unit 70 using vibration such as ultrasonic waves.

  Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the technical scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the technical scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  For example, in the above embodiment, the central control unit 80 controls the operations of the ribbon supply unit 10, the gripping unit 30, the guide unit 50, and the soldering unit 70. However, the present invention is not limited to this configuration, and a configuration may be adopted in which a plurality of control units are provided and the central control unit controls the plurality of control units in an integrated manner.

DESCRIPTION OF SYMBOLS 1 Solar cell module 10 Ribbon supply part 11 Roller 12 Ribbon 13 Bobbin 14 Step roller 15, 16 Guide roller 17 Chuck A
30 Gripping part 31 Cutter 32 LM guide 33 Servo motor 34 Block 35 Chuck B
50 Guide part 51, 52 Guide 53 Pressing roller 55, 56, 57 LM guide 58 Plate 70 Soldering part 71, 72 Servo motor 73 Soldering tool 74 Chuck C
80 Central control unit

Claims (8)

A gripping part having a chuck for gripping the supplied ribbon;
A first drive unit that applies a predetermined tension to the ribbon by a predetermined torque when soldering;
A soldering part having a soldering tool for soldering the ribbon on the surface of the solar cell;
A guide portion for restricting positional deviation of the ribbon during soldering;
A second drive unit for moving the soldering unit and the guide unit along a predetermined direction;
A control unit for controlling operations of the gripping unit, the first driving unit, the soldering unit, the guide unit, and the second driving unit;
With control of the control unit,
The solar cell bus bar, wherein the ribbon is soldered on the surface of the solar cell by the second driving unit moving the soldering unit and the guide unit along the predetermined direction. Wiring device.   By the control of the control unit, when the ribbon is soldered on the surface of the solar cell, the first driving unit applies the predetermined tension to the ribbon by the predetermined torque, 2. The bus bar wiring device for a solar cell according to claim 1, wherein the ribbon has straightness on the surface of the solar cell.   The guide portion includes two guides having grooves into which a ribbon at the time of soldering can be fitted, and a pressing roller for pressing the ribbon at the time of soldering, the groove, the pressing roller, and the soldering tool. The bus bar wiring device for a solar cell according to claim 1, wherein the front end of the solar cell is arranged on a straight line.   4. The solar cell bus bar wiring device according to claim 1, wherein soldering is performed while applying ultrasonic waves or other vibrations with the soldering tool. 5. A gripping part having a chuck for gripping the supplied ribbon;
A first drive unit that applies a predetermined tension to the ribbon by a predetermined torque when soldering;
A soldering part having a soldering tool for soldering the ribbon on the surface of the solar cell;
A guide portion for restricting positional deviation of the ribbon during soldering;
A second drive unit for moving the soldering unit and the guide unit along a predetermined direction;
A solar cell bus bar wiring device comprising the gripping unit, the first driving unit, the soldering unit, the guide unit, and a control unit for controlling the operations of the second driving unit. A method of wiring a bus bar,
The ribbon is soldered onto the surface of the solar cell by the second driving unit moving the soldering unit and the guide unit along the predetermined direction under the control of the control unit. A feature of a bus bar wiring method for a solar cell.   When the ribbon is soldered on the surface of the solar cell, the first driving unit applies the predetermined tension to the ribbon by the predetermined torque, so that the ribbon is connected to the solar cell. 6. The bus bar wiring method for a solar cell according to claim 5, wherein the bus bar wiring method has straightness on the surface.   The guide portion includes two guides having grooves into which a ribbon at the time of soldering can be fitted, and a pressing roller for pressing the ribbon at the time of soldering, the groove, the pressing roller, and the soldering tool. The solar cell bus bar wiring method according to claim 5, wherein the tip of the solar cell is arranged in a straight line.   The bus bar wiring method for a solar cell according to any one of claims 5 to 7, wherein the soldering is performed while applying ultrasonic waves or other vibrations by the soldering tool.

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