JP2011088165A - Soldering device and soldering method - Google Patents

Abstract

An object of the present invention is to provide a soldering apparatus and method capable of soldering a solar battery cell and a tab lead in a short time without damaging the solar battery cell.
A soldering device of the present invention is a soldering device (100) for soldering a solar cell (10) and a tab lead (15), the solar cell (10) and the tab lead (15). ) Are superposed, the solar cell (10) and the tab lead (15) are heated to a temperature below the solder melting point (60), the solar cell (10) and the tab lead ( And a soldering part (70) for heating the overlapping part with 15) to a temperature higher than the solder melting point.
[Selection] Figure 2

Description

  The present invention relates to a soldering apparatus and a soldering method for soldering a solar battery cell and a tab lead.

The solar cell module is configured by electrically connecting adjacent solar cells among a plurality of solar cells arranged in a row on one surface.
Conventionally, when solar cells are electrically connected to each other, the front side connection electrode of one of the adjacent solar cells and the back side connection electrode of the other solar cell are soldered using a tab lead. It is done by the soldering device to do.

  A conventional soldering apparatus includes a loading unit that sequentially arranges solar cells and tab leads, and a soldering unit that solders the solar cells and tab leads. The loading unit conveys the tab leads and the solar cells to the soldering unit while sequentially arranging the tab leads and the solar cells in a string form for each one-pitch feed on the conveyor that is carrying the one-pitch feed. The soldering part is a solar cell by heating and pressing the contact part between the solar cell and the tab lead at a temperature equal to or higher than the solder melting point using a hot air heater or the like for a short time until the next one-pitch feed. And tab lead.

  However, in the case of the soldering apparatus as described above, the temperature of the contact portion between the solar cell and the tab lead is rapidly raised from a substantially room temperature state to a temperature higher than the solder melting point in a short time. Cracks are likely to occur. Here, it is conceivable that the cracking rate of the solar battery cell is prevented by slowing the heating rate, but the cycle time for soldering the solar battery cell and the tab lead becomes longer, and the production efficiency is increased. It was difficult to improve. Further, since the temperature is rapidly increased, cracks may occur in the solar battery cell, leading to a decrease in yield.

On the other hand, for example, in the solar cell tab lead soldering device disclosed in Patent Document 1, a plate heater is provided as a preheating means. By providing such a plate heater as preheating means, it is possible to prevent cracking of the solar battery cell due to rapid heating.
For example, in the solar cell module manufacturing apparatus disclosed in Patent Document 2, a heating block is provided in the shroud. By providing such a heating block, it is effective to some extent for preventing cracking of the solar battery cell due to rapid heating, and the production efficiency can be improved to some extent.

JP 2006-147887 A JP 2005-191259 A

However, for example, in the soldering apparatus disclosed in Patent Document 1, there is no sufficient preheating, and the entire solar cell and the tab lead are heated to a temperature equal to or higher than the solder melting point in the immediate vicinity of the soldering portion, so that the production efficiency is improved. Is impossible. Moreover, there is a problem that cracks or the like occur in the solar battery cells when the temperature is rapidly raised in order to improve the production efficiency.
In addition, for example, when the solar battery cell and the tab lead are soldered by the solar battery module manufacturing apparatus disclosed in Patent Document 2 or the like, the entire solar battery cell is more than the solder melting point from the preheating stage to the soldering stage. Since the structure is heated to a high temperature, there is a problem that the solar battery cells are damaged and cracks are generated in some cases, and the production efficiency cannot be sufficiently improved. .

Here, with reference to FIG. 14, the temperature change of the whole photovoltaic cell and tab lead when the manufacturing apparatus of the solar cell module disclosed by patent document 2 etc. solders is demonstrated. FIG. 14 is a graph showing the temperature change of the entire solar cell and the tab lead, and the horizontal axis shows the position where the solar cell and the tab lead are conveyed in the solar cell module manufacturing apparatus disclosed in Patent Document 2, The vertical axis indicates the temperature of the entire solar battery cell and the tab lead. Above the graph in FIG. 14, a part of the solar cell module manufacturing apparatus 200 disclosed in Patent Document 2 is illustrated in correspondence with the position where the horizontal solar cell and the tab lead are conveyed. In a solar cell module manufacturing apparatus 200 shown in FIG. 14, a heating block 202 and a cooling block 203 are provided in a shroud 201. The solar cell module manufacturing apparatus 200 transports solar cells and tab leads in the shroud 201 in the direction of arrow D.
When the solar cell module manufacturing apparatus 200 transports the solar cells and the tab leads into the shroud 201, the entire solar cells and the tab leads are rapidly heated by the heating block 202 as shown in the graph of FIG. The solar cell module manufacturing apparatus 200 heats the temperature of the entire solar cell and the tab lead to a temperature higher than the solder melting point (for example, approximately 180 ° C.) by the heating block 202. Then, the entire solar cell and the tab lead are continuously heated to a temperature higher than the solder melting point, and the solar cell and the tab lead are soldered. Thereafter, the entire solar cell and the tab lead are cooled by the cooling block 203 in the cooling stage.

  In the conventional solar cell module manufacturing apparatus 200 and the like, the entire solar cell and the tab lead are continuously heated to a temperature higher than the solder melting point from the preheating stage to the soldering stage, and the solar battery cell and the tab lead are soldered. To do. That is, since it is a structure which transfers continuously from the preheating stage to the soldering stage, the time for heating to a temperature higher than the solder melting point cannot be controlled. Therefore, since the entire solar battery cell is heated at a high temperature for a long time, the solar battery cell may be damaged such as a crack. Further, when lead-free solder having a high solder melting point that has been used in recent years is used, there is a concern that the solar battery cell may be damaged.

  The present invention has been made in view of the above-described problems, and greatly improves the output per unit of time, and without causing damage such as cracks to the solar battery cell, the solar battery cell and the tab lead. It is an object to provide an apparatus and method for soldering.

In order to achieve the above object, a soldering apparatus according to the present invention is a soldering apparatus for soldering a solar battery cell and a tab lead, wherein the solar battery cell and the tab lead are overlapped with each other. A preheating part for heating the solar battery cell and the tab lead to a temperature below the solder melting point; and a soldering part for heating the overlapping part of the solar battery cell and the tab lead to a temperature higher than the solder melting point. It is characterized by that.
Further, the soldering portion includes a heating body disposed along the longitudinal direction of the tab lead, and the heating body is close to or in contact with the overlapping portion of the solar cell and the tab lead, The overlapping portion of the solar battery cell and the tab lead can be configured to be heated to a temperature higher than the solder melting point. In this case, it is possible to locally heat the overlapped portion of the preheated solar cell and the tab lead, and heat the overlapped portion of the solar cell and the tab lead to a temperature higher than the solder melting point in a short time. be able to.
Moreover, the said heating body can be comprised so that the several tab may be provided which presses the said tab lead with respect to the said photovoltaic cell. In this case, each pressing element can reliably press the tab lead against the solar battery cell.
In addition, a transport unit that transports the solar cells and the tab lead to the preheating unit and the soldering unit, the transport unit adsorbs the transported solar cells to a transport belt, By sandwiching the tab lead between the solar battery cell and the transport belt, the solar battery cell and the tab lead can be transported in a positioned state. In this case, the tab lead sandwiched between the solar battery cell and the transport belt can be transported while being positioned without being displaced from the solar battery cell.
Moreover, the said conveyance part adsorbs the said photovoltaic cell to the said conveyance belt by adsorbing the said photovoltaic cell through the cell adsorption hole of the said conveyance belt located in the both sides of the said tab lead currently conveyed. It can be constituted as follows. In this case, the tab lead sandwiched between the solar battery cell and the transport belt can be transported while being positioned without being displaced from the solar battery cell.
The transport unit may be configured to position the tab lead with respect to the transport belt by attracting the tab lead placed on the transport belt to the transport belt. In this case, when the solar battery cell is placed on the tab lead or the tab lead is placed on the transport belt, the tab lead can be accurately positioned without shifting.
In addition, the transport unit sucks the tab lead to the transport belt by sucking the tab lead through a tab lead suction hole of the transport belt, which is located below the tab lead placed on the transport belt. Can be configured to. In this case, when the solar battery cell is placed on the tab lead or the tab lead is placed on the transport belt, the tab lead can be accurately positioned without shifting.
The transport unit may be configured to suck the transported tab lead until immediately before the melting of the tab lead solder starts. In this case, misalignment of the tab lead can be reliably prevented during conveyance of the solar battery cell and the tab lead.
The tab lead supply unit further includes a tab lead supply unit that supplies the tab lead, and the tab lead supply unit connects the tab lead to the side where the tab lead is connected to the front connection electrode of the solar cell and the tab lead connects to the back side of the solar cell. It can be configured to be bent so as to have a step between the side connected to the electrode. In this case, the tab lead can be brought into surface contact with the solar battery cell without the tab lead floating on the solar battery cell.
In addition, the tab lead supply unit contacts the tab lead with the front connection electrode as the tab lead moves toward the front end of the tab lead on the side where the tab lead is connected to the front connection electrode of the solar battery cell. It can be configured to be inclined and molded. In this case, since the tab lead presses on the solar battery cell due to the elastic force of the tab lead, the solar battery cell and the tab lead can be kept positioned without being displaced.
In addition, before the soldered portion heats the overlapping portion of the solar battery cell and the tab lead to a temperature higher than the solder melting point, the temporary fixing of the tab lead and the solar battery cell is temporarily fixed. A stop device may be further provided. In this case, the tab lead can be transported in a positioned state without being displaced from the solar battery cell.
Moreover, the temporary fixing device can be configured to temporarily fix the tab lead by heating the tab lead superimposed on the front connection electrode of the solar battery cell. In this case, it is possible to more reliably prevent the tab lead from being displaced from the solar battery cell.
Moreover, it can comprise so that the soldering part may further comprise the cooling part which cools the melt | dissolved solder of the overlapping part of the said photovoltaic cell and the said tab lead from the one side in the longitudinal direction of the said tab lead. In this case, warpage of the solar battery cell after soldering can be eliminated.
A soldering method according to the present invention is a soldering method for soldering a solar battery cell and a tab lead, and the solar battery cell and the tab lead are joined in a state where the solar battery cell and the tab lead are overlapped. It has the preheating process heated to the temperature below a solder melting | fusing point, and the soldering process which heats the overlapping part of the said photovoltaic cell and the said tab lead to temperature higher than a solder melting | fusing point, It is characterized by the above-mentioned.

  According to the present invention, the solar battery cell and the tab lead can be soldered without causing damage such as cracks to the solar battery cell while greatly improving the output per hour.

It is a top view which shows the structure of a photovoltaic cell and a tab lead. It is a side view which shows the structure of a photovoltaic cell and a tab lead. It is a figure which shows the structure of a photovoltaic cell. It is a figure which shows schematic structure of a soldering apparatus. It is a perspective view which shows the structure of a tab lead loading apparatus. It is the figure which looked at the tab lead loading apparatus from the arrow A direction. It is the figure which looked at the tab lead loading apparatus from the arrow B direction. FIG. 6 is a diagram of the transport belt as viewed from the direction of arrow C. It is a side view of the tab lead which the tab lead loading device formed. It is a side view of the tab lead of other forms. It is a side view of the tab lead of a short specification among the tab leads mounted last. It is a figure which shows the state which mounted the first tab lead on the conveyance belt. It is a figure which shows the state which mounted the photovoltaic cell on the conveyance belt. It is a figure which shows the state which mounted the following (or last) tab lead. It is the perspective view which cut | disconnected a part of heating head. It is a figure which shows the structure of a heating head. It is a figure which shows the temperature change of the whole photovoltaic cell and tab lead concerning this embodiment. It is a figure which shows the state which the lead wire of a tab lead shrink | contracts when it cools. It is a figure which shows the temperature change of the whole photovoltaic cell and tab lead in the conventional soldering apparatus and the conventional soldering apparatus.

Hereinafter, the soldering apparatus 100 according to the present embodiment will be described with reference to the drawings. In the drawings, the front side (soldered solar cell and tab lead discharge side) of the soldering apparatus 100 is indicated by an arrow Fr, and the rear side (solar cell and tab lead supply side) is indicated by an arrow as necessary. Indicated by Rr.
Here, first, the solar cells 10 and the tab leads 15 to be soldered by the soldering apparatus 100 will be described with reference to FIGS. 1A, 1B, and 1C.
FIG. 1A is a plan view of a state in which a plurality of solar cells 10 are arranged in a string shape with tab leads 15 as viewed from the front connection electrode side (hereinafter referred to as the front side). FIG. 1B is a side view of a state in which a plurality of solar cells 10 are arranged in a string shape with tab leads 15 as viewed from the side. FIG. 1C is a diagram illustrating a configuration of the solar battery cell 10. FIG. 1C (a) is a plan view of the solar battery cell 10 as viewed from the front side. FIG. 1C (b) is a plan view of the solar battery cell 10 as viewed from the back side connection electrode side (hereinafter referred to as the back side).
The solar battery cell 10 is formed in a rectangular flat plate shape having a thickness of approximately 0.16 mm. As shown in FIG. 1C (a), on the front side of the solar battery cell 10 according to this embodiment, two front-side connection electrodes 11 are provided from one side to the opposite side of the solar battery cell 10. Further, on the front side of the solar battery cell 10, a plurality of finger portions 13 are provided from one side to the opposite side of the solar battery cell 10 so as to be orthogonal to the front-side connection electrode 11. Further, as shown in FIG. 1C (b), on the back side of the solar battery cell 10, two back side connection electrodes 12 are formed over one side facing from one side of the solar battery cell 10 like the front side connection electrode 11. Is provided. The front side connection electrode 11 and the back side connection electrode 12 are coated with solder for soldering to the tab lead 15.
On the other hand, as shown in FIGS. 1A and 1B, the tab lead 15 is a lead wire, and is formed in a strip-like flat plate shape having a thickness of approximately 0.2 mm. The tab lead 15 is formed using copper, and the surface thereof is coated with solder for soldering to the front side connection electrode 11 and the back side connection electrode 12.

Soldering is performed in a state where a plurality of solar cells 10 are arranged in a string with tab leads 15 as shown in FIGS. 1A and 1B. Specifically, the solar cells 10 are arranged at a predetermined interval, and one (front side) of half of the tab leads 15 is placed on the front connection electrode 11 of the solar cells 10 so as to overlap the tab leads 15. The other half (rear side) is placed on the back side connection electrode 12 of the adjacent solar battery cell 10 so as to overlap. In the present embodiment, adjacent solar cells 10 are connected by two tab leads 15. Here, the distance between the centers of the two tab leads 15 is W (see FIG. 1A).
The soldering device 100 heats the overlapping portion where the solar cells 10 arranged in a string and the tab leads 15 are superposed, so that the solder coated on each connection electrode and the tab lead 15 is melted. The battery cell 10 and the tab lead 15 are electrically connected.

Next, an outline of the soldering apparatus 100 according to the present embodiment will be described with reference to FIG. FIG. 2 is a diagram illustrating a schematic configuration of the soldering apparatus 100.
The soldering apparatus 100 according to this embodiment includes a plurality of components that perform processing related to soldering. Specifically, the soldering apparatus 100 includes a solar battery cell supply unit 20, a tab lead supply unit 30, a transport unit 50, a preheating unit 60, a soldering unit 70, and a cooling unit 80.
Here, each component will be briefly described. First, the solar cell supply unit 20 supplies the solar cell 10 to the transport unit 50. The tab lead supply unit 30 bends the tab lead 15, cuts it to a predetermined length, and supplies it to the transport unit 50. At this time, the solar cell supply unit 20, the tab lead supply unit 30, and the transport unit 50 operate in conjunction with each other, so that the solar cell 10 and the tab lead 15 are placed on the transport belt 51 of the transport unit 50 in FIGS. Are arranged in a string as shown in FIG.

  The conveyance part 50 conveys to the preheating part 60, the soldering part 70, and the cooling part 80 in the state which positioned the photovoltaic cell 10 and the tab lead 15. FIG. In the preheating unit 60, the temperature control device 61 heats the entire solar cell 10 and the tab lead 15 while controlling the solar cell 10 in the heating furnace 62 to a temperature not higher than the solder melting point. In the soldering portion 70, the overlapping portion of the connection electrode of the solar battery cell 10 and the tab lead 15 is locally heated, and the tab lead 15 is pressed against the solar battery cell 10, so that the solar battery cell 10 and the tab lead 15 Solder. In the cooling unit 80, the solar battery cell 10 and the tab lead 15 are cooled, and the overlapping part of the solar battery cell 10 and the tab lead 15 is solidified.

  According to the soldering apparatus 100 of the present embodiment, each of the above-described constituent elements can be soldered to the solar battery cell 10 and the tab lead 15 with high efficiency by singly or in cooperation with each other. Hereinafter, a specific configuration and operation process of each component will be described in detail.

(Solar cell supply unit 20)
The solar cell supply unit 20 performs a step of supplying the solar cell 10 to the transport unit 50.
As shown in FIG. 2, the solar cell supply unit 20 is provided with a cell loading device 21. The cell loading device 21 can reciprocate from the stocker 22 in which the solar cells 10 before being soldered are stacked and accommodated to the transport unit 50. Specifically, the cell loading device 21 adsorbs the solar cells 10 one by one from the stocker 22 and then places the cells 10 at predetermined positions on the conveyance belt 51 of the conveyance unit 50. In the middle of supplying the solar cells 10 to the transport unit 50, an imaging device (not shown) inspects whether or not the solar cells 10 are cracked, or a flux supply device (not shown) is connected to the front side of the solar cells 10. It can comprise so that a flux may be apply | coated to the connection electrode 11 and the back side connection electrode 12. FIG.

(Tab lead supply unit 30)
The tab lead supply unit 30 performs a process of bending and forming the tab lead 15 having a predetermined length and supplying it to the transport unit 50.
As shown in FIG. 2, the tab lead supply unit 30 includes a tab lead loading device 33 that bends the tab lead 15 having a predetermined length and places the bent tab lead 15 on the conveyor belt 51. Here, the tab lead loading device 33 will be described with reference to FIGS. FIG. 3 is a perspective view showing the configuration of the tab lead loading device 33. 4 is a view of the tab lead loading device 33 shown in FIG. 5A is a view of the tab lead loading device 33 shown in FIG.
As shown in FIG. 3, the tab lead loading device 33 is disposed on the side of the transport unit 50 and includes an upper die 37, a lower die 42, and the like.

The upper die 37 is one mold for bending the tab lead 15 and can be moved in the vertical direction and the horizontal direction by an upper die driving device (not shown).
As shown in FIGS. 4 and 5A, two protrusions 38 are formed in parallel on the lower surface of the upper mold 37 along the conveying direction of the conveying belt 51. Formed portions 39 for pressing the tab lead 15 protrude downward from the lower surface of each protrusion 38. The width dimension of the molding part 39 formed on each protrusion 38 substantially matches the width of the tab lead 15. Further, the distance between the adjacent molded portions 39 is the same distance as the distance W between the centers of the two tab leads 15 described in FIG. 1A (see FIG. 5A and the like). Further, as shown in FIG. 4, a stepped portion 40 is formed at the approximate center in the longitudinal direction of each molding portion 39. Each molding part 39 protrudes slightly toward the lower side from the front side of the molding part 39 with the stepped part 40 as a boundary. The step of the step portion 40 is approximately the thickness of the solar battery cell 10.

Further, as shown in FIG. 4, a plurality of suction holes 41 are formed in the protruding portions 38 of the upper mold 37 so as to be separated in the longitudinal direction. Each suction hole 41 is formed in the ridge portion 38 along the vertical direction, and the lower side is open to the lower surface of the molding portion 39. The tab lead 15 can be sucked to the upper die 37 by sucking the tab lead 15 through the suction holes 41 by a tab lead suction device (not shown).
Further, as shown in FIG. 4, heating elements 48 as a plurality of temporary fixing members are provided in the protrusions 38 on the front side of the upper die 37 so as to be separated in the longitudinal direction. Here, the heating element 48 is provided at two locations of the front end portion and the rear end portion of the front protrusion portion 38. The heating element 48 is formed in a pin shape, and at least its tip is heated to a solder melting point or higher. The heating element 48 can be heated by an electric resistance heating method or the like. Each heater element 48 is configured to be protruded downward from the lower surface of the molding portion 39 by a lifting mechanism (not shown) from the state accommodated in the molding portion 39 as indicated by a two-dot chain line in FIG. As will be described later, when the front side of the tab lead 15 is placed on the solar battery cell 10, each heater element 48 protrudes downward from the lower surface of the molding portion 39, thereby heating a predetermined position of the tab lead 15. Thus, a part of the solder of the tab lead 15 can be melted. By partially melting the solder of the tab lead 15, the tab lead 15 and the solar battery cell 10 are partially soldered and temporarily fixed. In addition, although this embodiment demonstrated the case where the heating element 48 was provided in two places, the front-end part and rear-end part in the front protrusion part 38, it is not restricted to this case but provided in two or more places. It may be done.

On the other hand, the lower die 42 is the other die for bending the tab lead 15 and can be moved in the vertical direction by a lower die driving device (not shown). Two protrusions 43 are formed on the upper surface of the lower mold 42 in parallel along the conveying direction of the conveying belt 51.
As shown in FIGS. 4 and 5A, a concave groove portion 44 for pressing the tab lead 15 is formed on the upper surface of each protrusion 43. The groove width dimension of the concave groove portion 44 formed in each protrusion 43 substantially matches the width of the tab lead 15. Further, the distance between the adjacent concave groove portions 44 is the same distance as the distance W between the centers of the two tab leads 15 described in FIG. 1A (see FIG. 5A and the like). Further, as shown in FIG. 4, stepped portions 45 are formed in the recessed groove portions 44 of the respective protrusions 43 of the lower mold 42. The step 45 is formed so as to be positioned vertically below the step 40 formed in each molding portion 39 of the upper die 37. That is, the position of the step 45 of the lower mold 42 is such that the step 40 of the upper mold 37 and the step 45 of the lower mold 42 sandwich the tab lead 15 disposed between the upper mold 37 and the lower mold 42 from above and below. When pressed in such a manner, a step is formed at the center of the tab lead 15A as shown in FIG. Further, the groove portion 44 of the lower mold 42 is slightly deeper on the rear side than on the front side of the groove portion 44 with each step portion 45 as a boundary. The level difference of the stepped portion 45 is approximately the thickness of the solar battery cell 10.

Next, the operation of the tab lead loading device 33 for bending the tab lead 15 will be described with reference to FIGS. 4 and 5A. Here, as shown in FIG. 2, the case where the tab lead supplied from one reel 32 is bent will be described. However, the case where the tab lead supplied from another adjacent reel 32 is bent is similarly described. Done at the same time.
First, as shown in FIG. 4, the tab lead chuck 35 pulls the tab lead 15 from the reel 32 and holds it in a horizontal state.
Next, the lower mold driving device raises the lower mold 42 and fits the tab lead 15 into the recessed groove portion 44 of the lower mold 42 for positioning (see also the lower mold shown by a two-dot chain line in FIG. 5A).

Subsequently, the tab lead cutter 36 cuts the tab lead 15. The tab lead chuck 35 releases the holding of the tab lead 15 and retracts backward. Next, the upper die driving device lowers the upper die 37 and presses the tab lead 15 fitted to the lower die 42 (see also the upper die indicated by a two-dot chain line in FIG. 5A).
Through the above-described operation, the tab lead 15 having a predetermined length drawn from the reel 32 is formed in the step portion 40 formed in the molding portion 39 of the upper die 37 and the groove portion 44 formed in the lower die 42 on the center side. The center is bent by the portion 45 and molded. Further, when the formed tab lead 15 is pressed between the upper die 37 and the lower die 42, the shape wound around the reel 32 is more straightened.

Next, with reference to FIG. 5A and FIG. 5B, the operation | movement which mounts the tab lead cut | disconnected by the tab lead loading apparatus 33 on the conveyance belt 51 is demonstrated. 5B is a view of the conveyor belt 51 shown in FIG.
After the upper die 37 presses the tab lead 15, the upper die 37 of the tab lead loading device 33 sucks the tab lead 15 through the suction hole 41. The upper mold drive device and the lower mold drive device release the upper mold 37 and the lower mold 42, respectively. Therefore, the tab lead 15 is attracted only to the upper mold 37.
Next, as shown in FIG. 5B, the upper die drive device, on which the tab lead 15 is attracted by the upper die driving device, is moved in the horizontal direction to above the conveyor belt 51 of the conveyor unit 50. Further, as indicated by a two-dot chain line in FIG. 5B, the upper die driving device lowers the upper die 37, and then the upper die 37 releases the tab lead 15 from suction. Therefore, the two tab leads 15 are placed at predetermined positions on the conveyance surface 52 of the conveyance belt 51 as indicated by a two-dot chain line in FIG. 5B. Here, the distance between the two tab leads 15 is the same distance as the distance W between the centers of the two tab leads 15 described in FIG. 1A.

By operating the tab lead loading device 33 in this way, the tab lead supply unit 30 can cut and bend the tab lead 15 to a predetermined length and supply the molded tab lead 15 to the transport unit 50. While the upper die 37 places the tab lead 15 at a predetermined position on the transport belt 51, the tab lead chuck 35 is pulled horizontally in the direction of the tab lead 15 with the cut portion of the tab lead 15 therebetween, and is held horizontally. Prepare for 15 bending.
Here, the cell loading device 21 of the solar cell supply unit 20 and the tab lead loading device 33 of the tab lead supply unit 30 described above place the solar cell 10 and the tab lead 15 on the conveyance belt 51 of the conveyance unit 50 in order, respectively. As shown in FIGS. 1A and 1B, a plurality of solar cells 10 are arranged in a string with tab leads 15.
In the above-described tab lead supply unit 30, the tab lead 15 is cut and bent, and the operation of placing the formed tab lead 15 on the conveyor belt 51 is described as being performed by the tab lead loading device 33 alone. A device for bending the tab lead 15 and a device for placing the molded tab lead 15 on the conveyor belt 51 may be separately configured.

  Here, the shape of the tab lead 15 bent by the upper die 37 and the lower die 42 will be described with reference to FIGS. 6A and 6B. FIG. 6A is a side view of the tab lead 15a formed by the tab lead loading device 33 according to the present embodiment. In FIG. 6A, the solar battery cell 10 is indicated by a two-dot chain line. The tab lead 15a is bent so that the front side is higher by the thickness of the solar battery cell 10 at the center. Accordingly, when the tab lead 15a is placed on the transport belt 51 of the transport unit 50, the tab lead 15a does not float on the solar battery cell 10 even if it is placed on the solar battery cell 10 already placed. The tab lead 15a and the solar battery cell 10 can be brought into wide surface contact.

  FIG. 6B is a side view of another form of the tab lead 15b. In FIG. 6B, the solar battery cell 10 is indicated by a two-dot chain line. The tab lead 15b is bent so that the front side is higher by the thickness of the solar battery cell 10 at the center. Further, the tab lead 15b is formed with a slight inclination so as to go downward as it goes toward the front end. That is, in the upper mold 37 and the lower mold 42 of the tab lead loading device 33, the molded part 39 of the upper mold 37 and the recessed groove part 44 of the lower mold 42 are respectively provided on the front side so that the tab lead 15b as shown in FIG. 6B can be molded. What is necessary is just to form the inclination which goes below as it goes. Therefore, when the tab lead 15b is placed on the transport belt 51 of the transport unit 50, the tab lead 15b does not float on the solar battery cell 10 even if it is placed on the solar battery cell 10 already placed. The tab lead 15b and the solar battery cell 10 can be brought into wide surface contact. Furthermore, since it inclines so that it may go to a lower side as it goes to the front side, the front side of the tab lead 15b acts so that the top of the photovoltaic cell 10 may be pressed by the elastic force of the tab lead 15b. Therefore, the tab lead 15b and the solar battery cell 10 can be brought into more contact with each other to prevent a deviation between them.

As shown in FIG. 7, the tab lead 15 to be placed first is not subjected to bending as described above. In the case of the first tab lead 15, the tab lead loading device 33 is provided with means such as providing a separate upper die and a lower die that are not bent to adsorb the tab lead 15 having no step formed in the center. Can be supplied.
Further, although the tab lead 15 that is finally placed on the transport belt 51 by the tab lead loading device 33 is bent, there is a specification that is shorter than the first tab lead 15 and the intermediate tab lead 15. Specifically, like the tab lead 15c shown in FIG. 6C, the rear side is short.

(Conveyor 50)
The conveyance part 50 performs the process of carrying intermittently to the preheating part 60, the soldering part 70, and the cooling part 80, positioning the photovoltaic cell 10 and the tab lead 15 in the state arrange | positioned at string form.
As shown in FIG. 2, the conveyance unit 50 includes a conveyance belt 51, conveyance rollers 55a and 55b, a suction device 56, and the like. The conveyance belt 51 is wound around a conveyance roller 55 a and a conveyance roller 55 b disposed at a position close to the cooling unit 80. The conveyor belt 51 is a thin flat belt, and is made of metal in order to increase thermal conductivity. Further, when a roller driving device (not shown) connected to the rotation shafts of the transport rollers 55a and 55b is driven, the respective transport rollers 55a and 55b are rotated in the arrow direction. The solar cells and the tab leads (hereinafter collectively referred to as “conveyed objects”) placed on the conveying surface 52 of the conveying belt 51 are rotated by the rotation of the conveying rollers 55a and 55b. The parts 80 are conveyed in the order.

Further, the suction device 56 is disposed below the conveyance surface 52 of the conveyance belt 51 over the longitudinal direction of the conveyance belt 51. The suction device 56 can position the photovoltaic cells 10 and the tab leads 15 placed on the transport surface 52 by attracting them to the transport belt 51. The operation of adsorbing the solar battery cell 10 and the tab lead 15 by the adsorption device 56 will be described later.
Further, as shown in FIG. 3, a plurality of tab lead suction holes 53 are continuously formed in the transport belt 51 along the circumferential direction of the transport belt 51. In the conveyance belt 51 of the present embodiment, two rows of tab lead suction holes 53 are formed on the left and right sides in the width direction of the conveyance belt 51. The tab lead suction hole 53 is formed at a position coinciding with the position where each tab lead 15 is placed on the conveyor belt 51 by the tab lead loading device 33 (see also FIG. 5B). That is, the distance between the rows of the tab lead suction holes 53 is the same as the distance W between the centers of the two tab leads 15 described with reference to FIG. 1A. As shown in FIG. 3, a plurality of cell suction holes 54 are continuously formed in the transport belt 51 over the circumferential direction of the transport belt 51 on both sides of each tab lead suction hole 53.

  Next, with reference to FIG. 3 and FIG. 7 to FIG. 9, an operation in which the conveyor belt 51 conveys the solar cells 10 and the tab leads 15 while adsorbing the solar cells 10 and the tab leads 15 by the adsorption device 56 will be described. . Here, FIG. 7A is a perspective view showing a state in which the tab lead loading device 33 has placed the first tab lead 15 on the conveyor belt 51. FIG.7 (b) is sectional drawing which cut | disconnected the II line | wire shown to Fig.7 (a) in the perpendicular direction, and was seen from the arrow direction. FIG. 8A is a perspective view showing a state in which the cell loading device 21 places the solar battery cell 10 on the transport belt 51. FIG. 8B is a cross-sectional view taken along the line II-II shown in FIG. FIG. 9A is a perspective view showing a state in which the tab lead loading device 33 places the next (or last) tab lead 15 on the conveyor belt 51. 9B is a cross-sectional view taken along the line III-III shown in FIG. 9A (a cross section including the solar battery cell and the tab lead in the heating furnace 62) in the vertical direction and viewed from the arrow direction. It is. 7A, 8A, and 9A illustrate an inlet 64 of a heating furnace 62 described later.

  First, as shown in FIG. 7A, the first tab lead 15 that is not bent by the tab lead loading device 33 is placed in parallel along a predetermined position on the transport surface 52, that is, along the continuous tab lead suction holes 53. To do. Subsequently, the suction device 56 sucks each tab lead 15 placed on the transport surface 52 through each tab lead suction hole 53. Specifically, as shown in FIG. 7B, the suction device 56 sucks each tab lead suction hole 57 positioned below each tab lead suction hole 53 of the transport belt 51, thereby The tab lead 15 is attracted to the conveyor belt 51. Accordingly, each tab lead 15 is positioned at a predetermined position placed on the transport belt 51.

  Next, as shown in FIG. 8A, the cell loading device 21 places the first solar battery cell 10 at a predetermined position on the transport surface 52. Specifically, the cell loading device 21 places the solar battery cell 10 so that the rear side of each tab lead 15 already placed and the back side connection electrode 12 of the solar battery cell 10 are aligned. When the solar battery cell 10 is placed on the tab lead 15, the solar battery cell 10 may come into contact with the tab lead 15 and the tab lead 15 may be displaced. However, since each tab lead 15 is positioned with respect to the conveyance belt 51 by the suction device 56, even if the solar battery cell 10 comes into contact, it does not move and can maintain a predetermined position.

  Subsequently, the suction device 56 sucks the solar cells 10 placed on the transport surface 52, specifically, each tab lead 15, through each cell suction hole 54. Specifically, as shown in FIG. 8B, the suction device 56 sucks through the cell suction holes 58 located below the cell suction holes 54 of the transport belt 51, thereby solar cells. 10 is adsorbed to the conveyor belt 51. Therefore, the solar battery cell 10 is positioned so that the predetermined position placed on the conveyor belt 51, that is, the tab lead 15 and the back side connection electrode 12 of the solar battery cell 10 coincide with each other. At this time, the solar cell 10 is adsorbed while being slightly bent in the vicinity of contact with each tab lead 15, so that each tab lead 15 is sandwiched between the solar cell 10 and the transport belt 51. Therefore, the photovoltaic cell 10 and each tab lead 15 can maintain the state positioned without deviation. In FIG. 8B, the state where the solar cell 10 is bent and fixed in the vicinity of the tab lead 15 by the adsorption hole 54 is emphasized.

Next, the photovoltaic cells 10 and the tab leads 15 are intermittently conveyed by the conveyance rollers 55 a and 55 b and the conveyance belt 51. Specifically, the roller driving device moves the transport belt 51 by a length corresponding to approximately one solar cell 10. At this time, since the adsorption device 56 continues to adsorb the solar battery cell 10, the solar battery cell 10 and the tab lead 15 do not shift due to vibration during transportation.
Next, as shown in FIG. 9A, the next tab lead 15 bent by the tab lead loading device 33 is placed at a predetermined position on the transport surface 52. Specifically, the front side of each tab lead 15 is placed so as to coincide with each front-side connection electrode 11 of the solar battery cell 10, and the rear side of each tab lead 15 is placed in parallel along the continuous tab lead suction hole 53. Put. Subsequently, the suction device 56 sucks the tab lead 15 newly placed on the transport surface 52 through the tab lead suction hole 53 and sucks it to the transport belt 51. Therefore, the rear side of the tab lead 15 is positioned at a predetermined position placed on the transport belt 51. Further, since the rear side of the tab lead 15 is positioned, the movement of the front side of the tab lead 15 is also regulated so as to coincide with the front connection electrode 11 of the solar battery cell 10.

  Further, as shown in FIGS. 6A and 6B, the tab lead 15 is bent at the center by the thickness of the solar battery cell 10, so that the front side of the tab lead 15 can be prevented from floating on the solar battery cell 10. Further, by placing the tab lead 15b with the front side of the tab lead inclined downward as shown in FIG. 6B, the front side of the tab lead 15b presses on the front connection electrode 11 of the solar cell 10 by the elastic force of the tab lead 15b. . Therefore, since the front side of the tab lead 15b and the front side connection electrode 11 of the solar battery cell 10 are in strong surface contact, it is possible to further prevent the tab lead 15b and the solar battery cell 10 from shifting.

Next, the cell loading device 21 places the next solar battery cell 10 on the rear side of the already placed tab lead 15. Specifically, the cell loading device 21 places the solar battery cell 10 so that the rear side of each tab lead 15 that has already been placed coincides with each back-side connection electrode 12 of the solar battery cell 10. Subsequently, the suction device 56 sucks the solar battery cell 10 placed on the tab lead 15 through the cell suction hole 54.
Next, the photovoltaic cells 10 and the tab leads 15 are intermittently conveyed by the conveying rollers 55 a and 55 b and the conveying belt 51 by a length corresponding to approximately one photovoltaic cell 10.
As described above, the tab lead loading device 33, the cell loading device 21 and the transport belt 51 are operated, so that the solar cells 10 and the tab leads 15 can be arranged in a string while accurately positioning on the transport belt 51. .

Next, a case where the tab lead loading device 33 places the last tab lead 15 at a predetermined position on the transport surface 52 will be described with reference to FIG. Here, it is assumed that a predetermined number of solar cells 10 are placed on the conveyor belt 51 as indicated by a two-dot chain line in FIG.
In this case, the tab lead loading device 33 places the last tab lead 15 bent and formed at a predetermined position on the conveyance surface 52. Specifically, the front side of each tab lead 15 is placed so as to coincide with each front-side connection electrode 11 of the solar battery cell 10, and the rear side of each tab lead 15 is placed in parallel along the continuous tab lead suction hole 53. Put. When the last tab lead 15 is a tab lead 15c with a short rear side as shown in FIG. 6C, the tab lead loading device 33 is mounted so that the front side of the tab lead 15c coincides with each front connection electrode 11 of the solar battery cell 10. Put.
Next, each heater element 48 provided on the upper die 37 of the tab lead loading device 33 described with reference to FIG. 4 protrudes downward from the lower surface of the molding portion 39, and two front and rear positions on the front side of each tab lead 15 (FIG. 9 ( The temporary attachment positions 59a and 59b) shown in a) are heated. Each heater element 48 heats each tab lead 15, so that the solder at the temporary attachment positions 59 a and 59 b of each tab lead 15 is melted and soldered to the front connection electrode 11 of the solar battery cell 10 to be temporarily fixed. The At this time, each tab lead 15 and the front-side connection electrode 11 of the solar battery cell 10 are temporarily fixed to be separated from each other on the front side of the tab lead 15, so that there is no deviation between the tab lead 15 and the solar battery cell 10. As described above, stable temporary fixing can be performed.

Thus, the last tab lead 15 is temporarily fixed to the solar battery cell 10 because the adsorption device 56 is configured not to adsorb the tab lead 15 to the transport belt 51 in the heating furnace 62 as described later. It is. That is, in the heating furnace 62, the rear side of the last tab lead 15 is not adsorbed and is not sandwiched between the solar battery cell 10 and the transport belt 51. Therefore, when the temporary fixing is not performed, the last tab lead 15 may be displaced from the solar battery cell 10 during transportation or soldering.
In addition, although the case where the last tab lead 15 was temporarily fixed was demonstrated here, you may make it temporarily fix all the tab leads 15 mounted on the photovoltaic cell 10. FIG. Moreover, although the case where the tab lead loading device 33 also serves as a temporary fixing device for temporarily fixing the tab lead 15 has been described, a dedicated temporary fixing device for temporarily fixing the tab lead 15 may be provided.

  Next, the conveyor belt 51 intermittently conveys the placed solar cells 10 and the tab leads 15 into the heating furnace 62 of the preheating unit 60 in order. In the heating furnace 62, the adsorption device 56 is configured to suck only the solar battery cell 10 placed on the tab lead 15 and not suck the tab lead 15. Specifically, as shown in FIG. 9B, the adsorption device 56 in the heating furnace 62 is not provided with the tab lead suction hole 57 described in FIGS. 7B and 8B. That is, in the heating furnace 62, the adsorption device 56 sucks only through the cell suction holes 58 located below the cell suction holes 54 of the transport belt 51 and sucks the solar battery cells 10 to the transport belt 51. . Even if the suction device 56 does not suck the tab leads 15, both sides of each tab lead 15 are pressed against the transport belt 51 by the solar cells 10, and thus the solar cells 10 and the tab leads 15 are misaligned during transport. There is no.

Here, the suction device 56 is configured not to suck the tab lead 15 in the heating furnace 62. When the tab lead 15 is directly sucked, the solder of the tab lead 15 melted by the heat in the heating furnace 62 is sucked. This is to prevent any trouble in the subsequent process.
Thus, the adsorption device 56 adsorbs the solar cells 10 to the conveyance belt 51 on both sides of the tab lead 15 in the heating furnace 62, so that the conveyance belt 51 positions the tab lead 15 and the solar cells 10. Can be transported. Further, it is possible to prevent the tab lead 15 from forming a trace of the tab lead suction hole 53. Even in the heating furnace 62, the suction device 56 can suck the tab lead 15 until the soldering of the tab lead 15 is started or until the soldering of the tab lead 15 is started. Also good. Thereby, the shift | offset | difference during conveyance with the tab lead 15 and the photovoltaic cell 10 can be prevented more reliably by the conveyance belt 51. FIG.
In the above description, the case where the suction device 56 sucks each tab lead 15 placed on the transport surface 52 through each tab lead suction hole 53 has been described. It can also be configured.

(Preheating part 60)
The preheating unit 60 performs a step of preheating the solar battery cell 10 and the tab lead 15.
As shown in FIG. 2, the preheating unit 60 includes a plurality of heaters 63 in the heating furnace 62 along the conveyance direction of the conveyance belt 51. Although the preheating part 60 of this embodiment is comprised from the three heaters 63, the quantity can be suitably changed according to the kind etc. of the photovoltaic cell 10. FIG. Each heater 63 is, for example, a hot air heater or an IR lamp. In addition to directly heating the solar cells 10 conveyed by the conveyor belt 51, the heaters 63 heat the atmosphere in the heating furnace 62 to uniformly heat the entire solar cells 10.

Further, the temperature at which each heater 63 is heated by the temperature control device 61 is controlled. Specifically, a plurality of temperature detection devices (not shown) are provided in the heating furnace 62 along the conveyance direction at positions close to the conveyance belt 51. The temperature control device 61 controls the heater 63 closer to the soldering portion 70 to have a higher temperature based on the temperature detection device. Therefore, in the heating furnace 62 in the preheating unit 60, the ambient temperature increases as the soldering unit 70 is approached from the inlet 64 of the heating furnace 62.
Here, with reference to FIG. 12, the temperature change of the whole photovoltaic cell 10 and the tab lead 15 in the preheating part 60 is demonstrated. FIG. 12 is a graph showing temperature changes of the entire solar battery cell and the tab lead, the horizontal axis shows the position where the solar battery cell and the tab lead are transported in the soldering apparatus, and the vertical axis shows the temperature of the solar battery cell and the tab lead. Is shown. Note that a part of the configuration of the soldering apparatus 100 is illustrated above the graph of FIG. 12 so as to correspond to the positions at which the horizontal solar cell and the tab lead are conveyed. Moreover, the temperature change of the whole photovoltaic cell 10 is shown with the continuous line, and the temperature change of the tab lead 15 is shown with the broken line.

As shown in FIG. 12, the temperature of the entire solar cell 10 and the tab lead 15 is raised by the temperature-controlled heater 63 toward the soldering portion 70 in the preheating portion 60. At this time, the temperature control device 61 controls the temperature so that the solar battery cell 10 is gradually heated so as not to crack.
The temperature control device 61 controls the temperature of the solar battery cell 10 positioned in front of the soldering portion 70 so as to heat it to a temperature not higher than the solder melting point, preferably lower than the solder melting point. In the example shown in FIG. 12, it is a case where solder melting | fusing point is 200 degreeC solder | pewter, Comprising: The temperature control apparatus 61 is heating so that the photovoltaic cell 10 may be about 150 degreeC. Since the solder melting point varies depending on the type of solder used, etc., the temperature controller 61 controls the temperature of the heating furnace 62, that is, the heater 63, according to the type of solder.

Thus, in the preheating part 60, the photovoltaic cell 10 is heated gradually. Moreover, in the preheating part 60, the photovoltaic cell 10 located in front of the soldering part 70 is heated to a temperature below the solder melting point. Therefore, the solar battery cell 10 is not damaged such as cracks. In the next soldering part 70, since the solar cell 10 and the tab lead 15 are preheated in the preheating part 60, the overlapping part where the tab lead 15 and the front side connection electrode 11 are overlapped, the tab lead 15 and the back side connection. The time for melting the solder in the overlapping portion where the electrode 12 is overlapped can be shortened.
In the preheating unit 60, the case where each heater 63 heats the solar battery cell 10 and the tab lead 15 has been described. However, a heater may be appropriately provided in the space between the conveyance belt 51 and the adsorption device 56. In this case, since the conveyor belt 51 heated by a heater provided as appropriate in the space between the conveyor belt 51 and the suction device 56 heats the solar cells 10 and the tab leads 15, the efficiency of preheating can be further improved. .

(Soldering part 70)
The soldering unit 70 performs a process of soldering the solar battery cell 10 and the tab lead 15.
As shown in FIG. 2, the soldering unit 70 is provided with a tab lead heating device 71. The tab lead heating device 71 includes a heating head 72 that heats the overlapping portion of the solar battery cell 10 and the tab lead 15 in the heating furnace 62, a heating head lifting device (not shown) that moves the heating head 72 up and down, and the like. Yes. Here, the heating head 72 will be described with reference to FIGS. 10 and 11. FIG. 10 is a perspective view in which a part of the heating head 72 is cut. Fig.11 (a) is sectional drawing which cut | disconnected the IV-IV line | wire shown in FIG. 10 in the perpendicular direction, and was seen from the arrow direction. FIG. 11B is a cross-sectional view of the VV line shown in FIG. 10 cut in the vertical direction and viewed from the arrow direction.

  As shown in FIGS. 10 and 11B, the heating head 72 is provided with two heating blocks 73 as heating elements in parallel along the conveyance direction of the conveyance belt 51, that is, the longitudinal direction of the tab lead 15. ing. The two heating blocks 73 are separated from each other in the width direction of the transport belt 51. The distance between the two heating blocks 73 is the same distance as the distance W between the centers of the two tab leads 15 described in FIG. 1A. In each heating block 73, two sheath heaters 74 as heat transfer bodies are embedded along the longitudinal direction. The sheath heater 74 has a nichrome wire processed into a coil shape at the center, an insulating material such as magnesium oxide filled around the nichrome wire, and a sheath covering the entire circumference of the insulating material. The heat transfer body is not limited to the sheath heater 74 and may be any heat transfer body as long as it can heat the heating block 73 and a presser 75 described later.

  Between the two sheath heaters 74 of each heating block 73, a plurality of pressing members 75 that respectively press the tab leads 15 from above are provided along the transport direction. Although the heating block 73 of the present embodiment includes seven pressing elements 75, the number thereof can be changed as appropriate according to the dimensions of the solar battery cell 10. Each pressing element 75 is formed in a pin shape. Further, each pressing element 75 is urged downward by an urging spring 76. Therefore, when each pressing element 75 presses the tab lead 15 from above, the pressing elements 75 are slightly lifted against the urging spring 76 so that each pressing element 75 presses the tab lead 15 and the pressing force against the tab lead 15 is increased. Adjusted appropriately. Each presser 75 is located in the heating block 73 heated by the sheath heater 74, so that each presser 75 itself is heated to a high temperature.

  Here, the sheath heater 74 is controlled by the temperature control device 61. Specifically, a temperature detection device (not shown) is provided at a position close to the heating block 73 or the pressing element 75. The temperature control device 61 controls the heating block 73 and the pressing element 75 at a temperature higher than the solder melting point and at a constant temperature based on the temperature detection device.

Next, an operation in which the tab lead heating device 71 solders the tab lead 15 to the front connection electrode 11 and the back connection electrode 12 of the solar battery cell 10 will be described with reference to FIGS.
First, the conveyor belt 51 intermittently conveys the solar cells 10 heated by the preheating unit 60, thereby conveying the solar cells 10 just below the heating head 72 as shown in FIG. At this time, the heating block 73 and the pressing element 75 are heated to a temperature higher than the solder melting point by the temperature control device 61 via the sheath heater 74.

  Next, as indicated by a two-dot chain line in FIGS. 11A and 11B, the heating head lifting device of the tab lead heating device 71 lowers the heating head 72 so that a plurality of pressings of each heating block 73 are pressed. The lower end of the child 75 presses each tab lead 15 disposed on the solar battery cell 10 from above. At this time, each pressing element 75 moves upward against the urging force of the urging spring 76, thereby preventing the solar cell 10 from being damaged due to the pressing force pressing the tab lead 15 being too strong. Can do.

  Further, the temperature control device 61 heats the heating block 73 and the pressing element 75 to a temperature higher than the solder melting point. Therefore, the temperature of the tab lead 15 rises as the heating block 73 and the presser 75 are lowered. Furthermore, when the heating block 73 and the pressing element 75 are close to the tab lead 15, the overlapping portion of the tab lead 15 and the front connection electrode 11 of the solar battery cell 10 has a temperature higher than the solder melting point, and the solder is completely melted. To do. Furthermore, the heat of the heating block 73 and the pressing element 75 is transmitted to the lower side of the solar battery cell 10, and the solder at the overlapping portion between the back-side connection electrode 12 and the tab lead 15 of the solar battery cell 10 is similarly melted. At this time, since the plurality of pressing elements 75 press the tab lead 15 against the solar battery cell 10, the tab lead 15 and the solar battery cell 10 are reliably brought into contact with each other, so that the soldering can be reliably performed. it can. In addition, it is not restricted to the part which the presser 75 contact | abutted among the overlapping parts of the tab lead 15 and the photovoltaic cell 10, but it is the tab lead similarly along the longitudinal direction of the tab lead 15 with the radiant heat of the presser 75 and the heating block 73. Since the solder of 15 and each connection electrode melts, the soldering is performed over the entire length of the tab lead 15.

The heating block 73 and the pressing element 75 are provided so as to coincide with the longitudinal direction of the tab lead 15. Accordingly, the tab lead heating device 71 locally heats the tab lead 15 and the portion (the connection electrodes 11 and 12 of the solar cell 10) where the solder of the solar cell 10 is coated. That is, the heating is not performed on the other portions of the solar battery cell 10 that is not coated with solder, and the temperature of only the connection electrodes 11 and 12 of the solar battery cell 10 is increased.
Here, with reference to FIG. 12, the temperature change of the whole photovoltaic cell 10 and the tab lead 15 in the soldering part 70 is demonstrated. In FIG. 12, the temperature change of the entire solar battery cell 10 is indicated by a solid line, and the temperature change of the tab lead 15 is indicated by a broken line.

The temperature of the tab lead 15 indicated by the broken line in FIG. 12 is raised to a temperature higher than the solder melting point when the temperature-controlled pressing element 75 and the heating block 73 approach in the soldering portion 70. At this time, since the solar battery cell 10 and the tab lead 15 are preheated by the preheating unit 60, the time required to reach a temperature higher than the solder melting point can be shortened. In the example shown in FIG. 12, the temperature of the tab lead 15 is raised from 150.degree. C. to 200.degree.
On the other hand, the temperature of the entire solar battery cell 10 shown by the solid line in FIG. 12 is such that only the portion coated with solder is locally heated in the soldering portion 70 and the other part of the solar battery cell 10 is heated. There is almost no change. In the example shown in FIG. 12, the temperature of the entire solar battery cell 10 remains at 150 ° C. Therefore, it is possible to prevent the solar cell 10 from being damaged due to the entire solar cell 10 being heated to a high temperature.

  Thus, in the soldering part 70, when heating the overlapping part of the solar battery cell 10 and the tab lead 15 to a temperature higher than the solder melting point, it is heated from a preheated state, so that the temperature higher than the solder melting point. It is possible to shorten the time until heating, and to improve the efficiency of soldering. At this time, in the soldering part 70, since the overlapping part of the photovoltaic cell 10 and the tab lead 15 is locally heated without heating the entire photovoltaic cell 10, the occurrence of damage to the photovoltaic cell 10 is prevented. it can. According to the soldering portion 70 of the present embodiment, the solar battery cell 10 and the tab lead 15 can be soldered in a short time of 3 seconds or less.

Further, as shown in FIG. 11 (b), the adsorption device 56 adsorbs the solar cells 10 to the transport belt 51 on both sides of the lower tab lead 15, so that the lower tab lead 15 and the solar cells 10 are absorbed. Is a positioned state. Moreover, the rear side of the upper tab lead 15 is positioned by the adjacent solar battery cell 10 to be soldered next. Therefore, the upper tab lead 15 is also positioned with respect to the solar battery cell 10. Therefore, even if the tab lead heating device 71 presses the upper tab lead 15 via the presser 75, soldering can be performed between each tab lead 15 and the solar battery cell 10 without deviation.
In addition, in the soldering part 70 mentioned above, the case where the tab lead 15 was pressed using the presser 75 was demonstrated. However, the present invention is not limited to this, and the heating block 73 omitting the presser 75 is heated without contacting the tab lead 15, or the heating block 73 omitting the presser 75 directly presses and heats the tab lead 15. May be. Furthermore, the pressing element 75 arranged in a quantity corresponding to the size of the solar battery cell 10 may locally heat the overlapping portion of the solar battery cell 10 and the tab lead 15. Any configuration may be used as long as the overlapping portion of the battery cell 10 and the tab lead 15 can be locally heated.
In the soldering part 70, after soldering, the tab lead heating device 71 raises the heating head 72 to prepare for the next soldering of the tab lead 15 and the solar battery cell 10.

(Cooling unit 80)
The cooling unit 80 performs a process of cooling the soldered solar battery cell 10 and the tab lead 15.
As shown in FIG. 2, the cooling unit 80 includes a cooling device 81. The cooling device 81 blows and cools the solar cells 10 and the tab leads 15 intermittently conveyed from the heating furnace 62 to cool them. The temperature of the cool air blown by the cooling device 81 is controlled by the temperature control device 61. Here, the cooling device 81 can also blow room temperature air. Furthermore, it is possible to blow cold air of 0 ° C. or lower. In the cooling unit 80, the temperature of the cold air blown by the temperature control device 61 according to the type of the solar battery cell 10 can be appropriately changed.

Here, with reference to FIG. 12, the temperature change of the whole photovoltaic cell 10 and the tab lead 15 in the cooling unit 80 will be described. In FIG. 12, the temperature change of the entire solar battery cell 10 is indicated by a solid line, and the temperature change of the tab lead 15 is indicated by a broken line.
The temperature of the tab lead 15 indicated by the broken line in FIG. 12 and the temperature of the entire solar battery cell 10 indicated by the solid line rapidly decrease in the cooling unit 80. Therefore, the solder melted at the overlapping portion of the solar battery cell 10 and the tab lead 15 can be solidified by a mechanism described later.

Next, the case where the cooling unit 80 cools the solder melted at the overlapping portion of the solar battery cell 10 and the tab lead 15 will be described with reference to FIG.
The cooling device 81 sequentially cools the transported tab lead 15 from one end in the longitudinal direction, whereby the lead wire 18 in the tab lead 15 having a high thermal conductivity is thermally contracted in the direction of arrow E. At this time, as shown in FIG. 13A, the lead wire 18 can be contracted while moving in the solder melted in the solder 16 (hereinafter referred to as melted solder 17). Therefore, since the molten solder 17 is solidified after the lead wire 18 is sufficiently heat-shrinked, the stress along the longitudinal direction of the tab lead 15 does not act between the lead wire 18 and the solder 16 after the solidification. Warpage of the battery cell 10 can be reduced.
In the case of natural cooling, the tab lead 15 is cooled from both ends in the longitudinal direction toward the center. At this time, the tab lead 15 is gradually cooled, so that it is not affected by the difference in thermal conductivity, and the thermal contraction of the lead wire 18 and the solidification of the molten solder 17 are performed simultaneously. Therefore, as shown in FIG. 13B, the lead wire 18 contracts in the center side, that is, in the direction of the arrow F, and is affected by the difference in the thermal expansion coefficient between the solar battery cell 10 and the copper in the tab lead 15. The cell 10 is warped.
In this way, by cooling the soldered solar battery cell 10 and the tab lead 15, the solar battery cell 10 is formed by the thermal contraction of the lead wire 18 after the molten solder 17 is solidified, as compared with the case where it is naturally cooled. Can reduce the warpage.
Next, the cooled solar cells are formed as strings connected in a string. The strings are connected in a plurality of rows and formed as a matrix solar cell panel. The solar cell panel is transferred to a laminating process (not shown) laminated with another member such as a glass plate.

  As mentioned above, according to the soldering apparatus 100 mentioned above, since the photovoltaic cell 10 and the tab lead 15 can be soldered in a short time, production efficiency improves. Moreover, according to the soldering apparatus 100 mentioned above, since the generation | occurrence | production of the photovoltaic cell 10 can be eliminated, a yield can be improved significantly.

  In the soldering apparatus 100 described above, the case where the solar cells 10 are connected by the two parallel tab leads 15 has been described. However, the present invention is not limited to this case, and the solar cells 10 are formed by one or three or more tab leads. May be connected. In this case, the tab lead supply unit 30 may be provided with the reel 32, the tab lead chuck 35, the protrusions 38 of the upper die 37, and the protrusions 43 of the lower die 42 according to the number of tab leads. Further, the transport unit 50 may be provided with a tab lead suction hole 53, a cell suction hole 54, a tab lead suction hole 57, and a cell suction hole 58 corresponding to the number of tab leads. In the soldering part 70, a heating block 73 corresponding to the number of tab leads may be provided.

  Here, in the above-described soldering apparatus 100, for example, the solar cell 10 and the tab lead 15 are transported in a positioned state without being misaligned. In this case, the soldering apparatus 100 superimposes the solar battery cell and the tab lead with a preheating portion that heats the solar battery cell and the tab lead to a temperature below the solder melting point, and the solar battery cell and the tab lead. It is not restricted to the structure provided with the soldering part which heats a part to temperature higher than solder melting | fusing point.

DESCRIPTION OF SYMBOLS 10: Solar cell 11: Front side connection electrode 12: Back side connection electrode 13: Finger part 15: Tab lead 20: Cell supply part 21: Cell loading apparatus 30: Tab lead supply part 33: Tab lead loading apparatus 37: Upper mold 38: Projection Part 39: Molding part 40: Step part 42: Lower mold 43: Projection part 44: Groove part 45: Step part 48: Heater 50: Conveying part 51: Conveying belt 53: Tab lead adsorbing hole 54: Cell adsorbing hole 56: Adsorption device 60: Preheating part 70: Soldering part 72: Heating head 73: Heating block (heating body)
74: Sheath heater 75: Presser 80: Cooling unit

Claims (14)

A soldering device for soldering solar cells and tab leads,
In a state where the solar battery cell and the tab lead are overlapped, a preheating part that heats the solar battery cell and the tab lead to a temperature equal to or lower than a solder melting point,
A soldering apparatus, comprising: a soldering portion that heats an overlapping portion of the solar battery cell and the tab lead to a temperature higher than a solder melting point. The soldering portion includes a heating body disposed along a longitudinal direction of the tab lead,
The heating body heats the overlapping portion of the solar battery cell and the tab lead to a temperature higher than the solder melting point by approaching or contacting the overlapping portion of the solar battery cell and the tab lead. The soldering apparatus according to claim 1.   The soldering apparatus according to claim 2, wherein the heating body includes a plurality of pressing elements that press the tab lead against the solar battery cell. A transport unit that transports the solar cell and the tab lead to the preheating unit and the soldering unit;
The transport unit adsorbs the solar battery cell being transported to a transport belt, and positions the solar battery cell and the tab lead by sandwiching the tab lead between the solar battery cell and the transport belt. The soldering apparatus according to claim 1, wherein the soldering apparatus is transported in a state where the soldering is performed.   The conveyance unit adsorbs the solar cells to the conveyance belt by adsorbing the solar cells via cell adsorption holes of the conveyance belt located on both sides of the tab lead being conveyed. The soldering apparatus according to claim 4, wherein the soldering apparatus is a soldering apparatus.   6. The solder according to claim 4, wherein the conveyance unit positions the tab lead with respect to the conveyance belt by attracting the tab lead placed on the conveyance belt to the conveyance belt. 7. Attachment device.   The conveyance unit adsorbs the tab lead to the conveyance belt by adsorbing the tab lead through a tab lead adsorption hole of the conveyance belt located below the tab lead placed on the conveyance belt. The soldering apparatus according to claim 6.   The soldering apparatus according to claim 7, wherein the transport unit sucks the tab lead being transported until immediately before the melting of the solder of the tab lead is started. A tab lead supply section for supplying the tab lead;
The tab lead supply unit has a step between the tab lead and the side where the tab lead is connected to the front connection electrode of the solar cell and the side where the tab lead is connected to the back side connection electrode of the solar cell. The soldering apparatus according to claim 1, wherein the soldering apparatus is bent.   The tab lead supply unit is configured so that the tip of the tab lead comes into contact with the front connection electrode as the tab lead is directed to the tip of the tab lead on the side where the tab lead is connected to the front connection electrode of the solar battery cell. The soldering apparatus according to claim 9, wherein the soldering apparatus is formed while being inclined. Before heating the overlapping portion of the solar cell and the tab lead to a temperature higher than the solder melting point by the soldering portion,
The soldering apparatus according to any one of claims 1 to 10, further comprising a temporary fixing device that temporarily fixes the tab lead and the solar battery cell in an overlapped state.   The soldering apparatus according to claim 11, wherein the temporary fixing device temporarily fixes the tab lead superimposed on the front connection electrode of the solar battery cell by heating.   The cooling part which cools from the one side in the longitudinal direction of the tab lead the solder which the melted part of the superposition part of the photovoltaic cell and the tab lead by the soldering part is further provided. The soldering device described. A soldering method for soldering solar cells and tab leads,
A preheating step of heating the solar battery cell and the tab lead to a temperature not higher than a solder melting point in a state where the solar battery cell and the tab lead are overlapped,
A soldering method comprising: a soldering step of heating an overlapping portion of the solar battery cell and the tab lead to a temperature higher than a solder melting point.

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