The present specification claims priority from Japanese Patent Application No. 2007-072697, filed on Mar. 20, 2007 in the Japan Patent Office, the entire contents of which are hereby incorporated by reference herein.
1. Field of the Invention
The present invention relates to a photovoltaic cell holder that holds a photovoltaic cell (hereinafter also referred to simply as a cell) and interconnectors when soldering the interconnectors to the photovoltaic cells that form a photovoltaic module during manufacture of photovoltaic module.
2. Description of the Background Art
JP-H11-87756-A and JP-2003-168811-A disclose an interconnector soldering technique in which, when interconnectors are positioned on and soldered to a photovoltaic cell, the interconnectors are pressed and supported against the cell by bar- or rod-shaped rigid press members and heated to melt the solder, after which the cell is cooled.
However, conventional interconnector soldering using press members has the following drawbacks.
First, in an arrangement in which the interconnectors to be mounted on top and bottom surfaces of a cell are pressed and supported by rod-shaped rigid press members, bending and warping of the cell during heating and cooling causes partial separation of the interconnectors from the cell. As a result, the strength of the weld is not uniform. Moreover, when the cell is held strongly enough to prevent it from deforming, the cell may be damaged.
Second, during soldering, the interconnectors sometimes weld to the press members and the photovoltaic cell cannot be separated from the press members.
Third, pressing and supporting the interconnectors at multiple places using a plurality of bars causes changes in thermal conditions between the held and the free sections of the interconnectors. This unevenness in thermal conditions can cause unevenness in welding.
Neither JP-H11-87756-A nor JP-2003-168811-A discloses a solution to the above-described drawbacks.
The present invention has as its object to obtain uniform welding quality between a photovoltaic cell and interconnectors without the interconnectors and the press members welding to each other during soldering of the interconnectors onto the photovoltaic cell by holding the interconnectors tightly over substantially all areas while at the same time allowing flux gas to escape.
To achieve the above-described object, the present invention provides a photovoltaic cell holder to hold both a photovoltaic cell and interconnectors in order to soldering the interconnectors to a top surface and a bottom surface of the photovoltaic cell. The photovoltaic cell holder includes an upper holder and a lower holder. The upper holder includes an upper retainer configured to press the interconnectors against the top surface of the photovoltaic cell. The upper retainer has a plurality of elastic stick-shaped members and one or more flange parts provided at one end of the stick-shaped members. The lower holder includes one or more bar-shaped lower supports configured to support the interconnectors against the bottom surface of the photovoltaic cell. The lower supports extend parallel to the interconnectors. A surface of each lower support that contacts the interconnectors has either a groove or a hole formed therein.
In addition, a tapered portion may be provided at each of both ends of the flange part of the upper retainer in a long direction of the interconnectors. The flange part of the upper retainer may be attached to a plurality of the stick-shaped members and has either a groove or a hole formed therein. A peel-off layer may be provided on either a contact portion of the upper retainer that contacts the interconnectors or a contact portion of the lower support that contacts the interconnectors.
The present invention provides at least one of the following effects.
First, using the lower support and the upper retainer of the present invention enables uneven welds and weld defects caused by contacting and holding the interconnectors uniformly with flanges or bars to be prevented.
Second, because the lower support and the upper retainer of the present invention are constructed so as to allow flux gas to escape, welding malfunctions in the form of the interconnectors being welded to the lower support or the upper retainer can be prevented.
Third, by providing a peel-off layer on the lower support and the upper retainer of the present invention, welding of the interconnectors to the lower support or the upper retainer can be prevented.
Other features and advantages of the present invention will be apparent from the following description when taken in conjunction with the accompanying drawings, in which like reference characters designate similar or identical parts throughout the several views thereof.
A detailed description will now be given of illustrative embodiments of the present invention, with reference to the accompanying drawings. In so doing, specific terminology is employed solely for the sake of clarity, and the present disclosure is not to be limited to the specific terminology so selected. It is to be understood that each specific element includes all technical equivalents that operate in a similar manner and achieve a similar result.
As shown in
As shown in
In the soldering step, the photovoltaic cells 10 and the interconnectors 20 are positioned and held using the photovoltaic cell holder 30, with soldering carried out using a transport conveyer 60 that conveys the photovoltaic cell holder 30 and a heating space 70. The heating space 70 is a chamber-like space disposed so as to straddle the transport conveyer 60 from above and below, and is a space formed in such a way that a transport surface of the transport conveyer 60 runs through an interior of the heating space 70, and a plurality of heating means 71 is positioned inside the heating space 70.
The holder 30 transports the photovoltaic cells 10 to the heating space 70 with the transport conveyer 60, with the interconnectors 20 pressed against the electrodes 11 of the photovoltaic cell 10.
Inside the heating space 70, the plurality of heating means 71, such as a plurality of heaters, is arranged both above and below the transport conveyer 60.
The photovoltaic cells 10, having been brought to the heating space 70 by the holder 30, are then heated on both top and bottom surfaces simultaneously by the heating means 71, melting the interconnector solder.
The heated photovoltaic cells 10 are then removed from the heating space 70 by the transport conveyer 60 and are cooled either under room temperature conditions or by a cooling means such as fans, not shown, thus hardening the solder and completing soldering.
A more detailed description is now given of the photovoltaic cell holder 30 according to the present invention.
The photovoltaic cell holder 30 holds the photovoltaic cell 10 and the interconnectors 20 simultaneously, with the interconnectors 20 positioned on the top and bottom surfaces of the photovoltaic cell 10.
The photovoltaic cell holder 30, as shown in
The upper holder 40 and the lower holder 50, although not shown, are constructed so as to be positioned and set by positioning pins provided at two locations on a press part 51 and positioning holes provided at two locations on a press part 41.
The interconnectors 20 are set on top of supports 52 of the lower holder 50, the photovoltaic cell 10 is set on top of the interconnectors 20, and the upper holder 40 is positioned from above by the positioning pins and the positioning holes and set on top of the photovoltaic cell 10. In this manner, the photovoltaic cell 10 and the interconnectors 20 are set on the holder 30.
The upper holder 40, as shown in
The press part 41 holds the photovoltaic cell 10 at both side edges of the photovoltaic cell 10.
The press bars 42 and the flange parts 43 mounted on the press bars 42 hold the interconnectors 20.
The lower holder 50, as shown in
The press parts 51 hold the photovoltaic cell 10 at both side edges thereof. The supports 52 support the interconnectors 20.
The supports 52, as shown in
Next, using
Both side edges of the photovoltaic cell 10 are sandwiched between the press parts 41 and 51 and the photovoltaic cell 10 is held level. As a result, bending of the cell 10 due to heating and cooling can be prevented.
The interconnectors 20 mounted on the top surface of the cell 10 are pressed and held by the plurality of elastic upper retainers 44. As noted above, the upper retainers 44 are comprised of press bars 42 and flange parts 43 mounted on the tips of the press bars 42. The press bars 42 are stick-shaped and elastic, and therefore the interconnectors 20 held by the flange parts 43 are held tightly against the photovoltaic cell 10 and in that state are heated and cooled, and further, are contacted and held over substantially all areas by the same material, thus conducting heat uniformly to all areas of the interconnectors 20. As a result, uniform welding quality can be obtained.
The flange parts 43 are spaced as shown in
The interconnectors 20 mounted on the bottom surface of the cell 10 are held by the supports 52. The supports 52 are bar-shaped, and thus the interconnectors 20 supported by the supports 52 are held tightly against the photovoltaic cell 10 and in that state are heated and cooled, and further, are contacted and held over substantially all areas by the same material, thus conducting heat uniformly to all areas of the interconnectors 20. As a result, uniform welding quality can be obtained.
Grooves 54 are formed in the supports 52 as shown in
It should be noted that, with the holder 30 of the construction described above, interconnectors 20 may be disposed on both the top and bottom sides of the cell 10 as shown in
A description is now given of the upper retainers 44 and the lower supports 52 of a second embodiment of the present invention, using
As shown in
Further, a peel-off layer 433 made of fluoresin or the like may be provided on a contact surface 431 of the flange part 43 that contacts the interconnectors 20. The peel-off layer 433 may be provided by such methods as coating the surface of the side of the flange part 43 that contacts the interconnectors 20 with a fluid composed of fluoresin or the like, or affixing a resin sheet to the surface of the side of the flange part 43 that contacts the interconnectors 20 with an adhesive or the like. Such an arrangement effectively prevents the welding together of the interconnectors 20 and the upper retainer 44.
Each lower support 52 has a groove 522 provided in a bar-shaped member as shown in
Alternatively, instead of a bar-shaped member the lower support 52 may be a U-shaped jig like that shown in
A description is now given of upper retainers 44 and lower supports 52 of a third embodiment of the present invention using
The interconnector upper retainer 44 of the upper holder 40, as shown in
The press bars 42 are stick-shaped and elastic, and therefore the interconnectors 20 held by the flange part 43 are held tightly against the photovoltaic cell 10 and in that state are heated and cooled, thus enabling uniform welding quality to be obtained.
The attached flange part 43 may have a slot 434 formed therein as shown in
The lower supports 52 of the lower holder 50 may be provided with a plurality of holes 524 that penetrate lower support 52 as shown in
Further, the lower supports 52, as shown in
As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.
Number | Date | Country | Kind |
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2007-072697 | Mar 2007 | JP | national |