TW201427048A - Solar cell and module comprising the same - Google Patents

Abstract

A solar cell and a module comprising the same are provided. The solar cell comprises a substrate having a light receiving surface, a plurality of finger bar electrodes disposed on the light receiving surface, a first bus bar electrode, and a second bus bar electrode. The finger bar electrodes extend along a first direction and are separately disposed along a second direction which is perpendicular to the first direction. The first and the second bus bar electrodes are separately disposed along the first direction and include a plurality of first and second electrode portions separately disposed along the second direction. The first and the second electrode portions are alternately located at different sides of the first direction and are connected to the finger bar electrodes so as to permit electric connection between the finger bar electrodes. The design of the solar cell can reduce the consumption of a conductive paste of the bus bar electrodes so as to reduce the manufacturing costs as well as provide a sufficient welding stability for solder ribbons.

Description

Solar cell and its module

The invention relates to a battery and a module thereof, in particular to a solar battery and a module thereof.

Known twinned solar cells mainly comprise: a battery body for converting light energy into electrical energy, and a front electrode and a back electrode for conducting current. The front electrode includes at least one elongated bus bar electrode and a plurality of finger bar electrodes laterally connected to the bus electrode. The bus electrode and the finger electrodes are manufactured by applying a conductive paste to a light receiving surface of the battery body by screen printing, and are solidified by a sintering process.

However, as the price of the conductive paste continues to increase, especially the silver paste having a better conductivity is expensive, and the bus electrode of the conventional battery has a continuous strip shape, the conductive paste is consumed in a large amount, resulting in a large amount of electricity. The production cost of the battery is high, and therefore, how to improve the structure of the bus electrode to save cost is an important issue. On the other hand, after the battery is manufactured, it is necessary to additionally solder a ribbon to the bus electrode of the battery to arrange a plurality of cells in series to form a battery module. Therefore, in the improvement of the bus electrode structure, it is also necessary to consider whether the welding bonding force between the bus electrode and the ribbon wire is sufficient. If the bonding force is not good, it is easy to generate welding when the module is packaged or used in subsequent use. The problem of wire stripping, which in turn affects product reliability.

Therefore, the object of the present invention is to provide a production cost saving Solar cells and their modules that maintain product reliability.

The solar cell of the present invention comprises: a substrate having a light receiving surface; and a plurality of finger electrodes on the light receiving surface, a first bus electrode and a second bus electrode.

The finger electrodes all extend in a first direction and are spaced apart in a second direction perpendicular to the first direction. The first bus electrode includes a plurality of first electrode portions spaced apart along the second direction. The second bus electrode is spaced apart from the first bus electrode along the first direction, the second bus electrode includes a plurality of second electrode portions spaced along the second direction, and the second electrode portion and the second electrode portion The positions of the first electrode portions in the first direction are staggered. Each of the finger electrodes connects one of the first electrode portions and one of the second electrode portions.

The solar cell module of the present invention comprises: a first plate and a second plate disposed oppositely, a plurality of solar cells as described above and arranged between the first plate and the second plate, and a A package between a plate and the second plate and surrounding the solar cells.

The effect of the present invention: by using the first bus electrode and the second bus electrode of the innovative structure to replace the known long-shaped bus electrode with a solid structure, the amount of conductive paste can be reduced to reduce the production cost, and at the same time It also provides sufficient welding area and welding bonding force to meet the requirements of welding stability to maintain product reliability. Further, the first electrode portions and the second electrode portions are alternately arranged, and can be used to connect the finger electrodes to form a continuous current conduction path.

The foregoing and other technical aspects, features and advantages of the present invention will be apparent from the Detailed Description of the <RTIgt; Before the present invention is described in detail, it is noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to Figures 1, 2 and 3, a first preferred embodiment of the solar cell module of the present invention comprises: a first plate 1 and a second plate 2 disposed opposite each other, and a plurality of arrays arranged on the first plate 1 The solar cell 3 between the second plate 2 and at least one of the first plate 1 and the second plate 2 are wrapped around the solar cells 3.

The first plate 1 and the second plate 2 are not particularly limited in implementation, and a glass or plastic plate may be used, and the plate on one side of the light receiving surface of the battery must be permeable to light. The material of the encapsulant 4 is, for example, a translucent ethylene vinyl acetate copolymer (EVA). Of course, other materials suitable for packaging may be used.

The solar cells 3 are electrically connected through ribbons not shown. The configurations of the solar cells 3 are the same, and only one of them will be described below as an example.

The solar cell 3 includes a substrate 31, a plurality of finger electrodes 32, a first bus electrode 33, a second bus electrode 34, and two outer finger electrodes 32.

The substrate 31 has an opposite light receiving surface 311 and a back surface (not shown). Actually, an emitter layer (not shown) is disposed on the inner side of the light receiving surface 311, and the emitter layer is additionally disposed. An anti-reflection layer is disposed on the surface. Wherein, the substrate 31 is, for example, a germanium substrate, and one of the substrate 31 and the emitter layer is n The type of semiconductor, the other is a p-type semiconductor, which in turn forms a p-n junction. The material of the anti-reflective layer such as tantalum nitride can be used to reduce light reflection to increase the amount of light incident. Since the substrate 31, the emitter layer, and the anti-reflection layer are not the improvement points of the present invention, they will not be described.

The two outer finger electrodes 32 ′ are located on the light receiving surface 311 of the substrate 31 , and both extend along a first direction 51 , and the two outer finger electrodes 32 ′ are perpendicular to each other in the first direction 51 . The second direction 52 is spaced apart.

The finger electrodes 32 are also located on the light receiving surface 311 of the substrate 31 and are located between the two outer finger electrodes 32'. The finger electrodes 32 all extend along the first direction 51, and the finger electrodes 32 are spaced apart from each other along the second direction 52.

The first bus electrode 33 is located on the light receiving surface 311 and includes a plurality of first electrode portions 35 arranged at intervals in the second direction 52. Each of the first electrode portions 35 includes a first segment 351 and a second segment 352 disposed opposite to each other along the second direction 52, and a first connection between the first segment 351 and the second segment 352. Paragraph 353. The length d1 of the first segment 351 along the first direction 51 and the length d2 of the second segment 352 along the first direction 51 are greater than the length d3 of the first engaging segment 353 along the first direction 51. In the present embodiment, d1 = d2, but the implementation is not limited thereto.

Specifically, one of the first electrode portions 35 of the present embodiment is connected between one of the outer finger electrodes 32' and the first finger electrode 32. The other first electrode portions 35 are respectively connected between the nth and n+1th finger electrodes 32, and are even numbers such as n=2, 4, 6, 8, and so on. Except for the outer finger electrode In addition to the first electrode portion 35 between the first finger electrode 32 and the first finger portion 35, the first segment 351 of each of the other first electrode portions 35 is connected to the nth finger electrode 32, and each of the first electrodes The second segment 352 of the portion 35 is connected to the n+1th finger electrode 32. The first electrode portions 35 are similar to an hourglass shape, and the length of each of the first electrode portions 35 along the first direction 51 is gradually reduced from the first segment 351 and the second segment 352 toward the first engaging segment 353. .

The second bus electrode 34 is located on the light receiving surface 311 and is spaced apart from the first bus electrode 33 along the first direction 51 . The second bus electrode 34 includes a plurality of second electrode portions 36 spaced apart along the second direction 52, and the second electrode portions 36 are interleaved with the positions of the first electrode portions 35 in the first direction 51. Arranging, that is, the second electrode portions 36 and the first electrode portions 35 are located on different lines extending along the first direction 51, thereby allowing the finger electrodes 32 to pass through the first electrodes The portion 35 is electrically connected to the second electrode portion 36.

The second electrode portion 36 of the present embodiment has the same structure as the first electrode portion 35, and each of the second electrode portions 36 includes a third segment 361 and a fourth segment 362 which are oppositely disposed along the second direction 52, and A second engaging section 363 between the third section 361 and the fourth section 362. The length d4 of the third segment 361 along the first direction 51 and the length d5 of the fourth segment 362 along the first direction 51 are greater than the length d6 of the second engaging segment 363 along the first direction 51. In the present embodiment, d4=d5, but the implementation is not limited thereto.

The third segment 361 of the second electrode portion 36 between any two adjacent first electrode portions 35 of the present embodiment and the second segment 352 of one of the first electrode portions 35 are connected to the same finger electrode 32, The fourth segment 362 and the other first The first segment 351 of the electrode portion 35 is connected to the same finger electrode 32.

Specifically, one of the second electrode portions 36 of the present embodiment is connected between one of the outer finger electrodes 32' and the last one of the finger electrodes 32. The other second electrode portions 36 are connected between the mth and m+1th finger electrodes 32, respectively, and have odd numbers such as m=1, 3, 5, 7, and so on. The third segment 361 of each of the second electrode portions 36 is connected to the mth finger electrode 32 except for the second electrode portion 36 between the outer finger electrode 32' and the last finger electrode 32. The fourth segment 362 of each second electrode portion 36 is connected to the m+1th finger electrode 32. The second electrode portions 36 are similar to an hourglass shape, and the length of each of the second electrode portions 36 along the first direction 51 is gradually reduced from the third segment 361 and the fourth segment 362 toward the second engaging segment 363. .

As can be seen from the above description, each of the finger electrodes 32 of the present invention is connected to one of the first electrode portions 35 and one of the second electrode portions 36.

The solar cell 3 actually further includes a back electrode (not shown) on the back surface of the substrate 31 for use with the first bus electrode 33, the second bus electrode 34, the outer finger electrode 32' and the finger The electrode 32 cooperates with the output of electric energy, but since the back electrode is not an improvement of the present invention, it will not be described.

The present invention improves the structure of the first bus electrode 33 and the second bus electrode 34, and the two include the first electrode portion 35 and the second electrode portion 36 at equal intervals, respectively, instead of the known elongated and solid structure. The bus electrode can reduce the amount of conductive paste of the bus electrode to reduce the production cost.

In addition, the hourglass-like design of each of the first electrode portion 35 and the second electrode portion 36 of the embodiment passes through the first connecting segment 353 and the second engaging segment. The reduction of the length of the 363 along the first direction 51 also helps to save the slurry, and at the same time maintains the first segment 351, the second segment 352, the third segment 361 and the fourth segment 362 along the first The length of the direction 51, on the one hand, enables the first electrode portion 35 and the second electrode portion 36 to have sufficient connection strength with the connected finger electrodes 32, and on the other hand, can provide sufficient welding area and welding bonding force, so that the subsequent The ribbon wires soldered to the first bus electrode 33 and the second bus electrode 34 can be firmly soldered and attached. In this way, the invention can reduce the production cost, and can also meet the requirements of the welding stability, so that the welded module can pass the subsequent tensile test to maintain the reliability of the product.

In addition, after the soldering wire is soldered, it actually has the function of connecting the equally spaced finger electrodes 32. However, since the soldering wire may have a local portion of the solder joint, if the first electrode portion 35 of the present invention is When the second electrode portion 36 is not formed in a staggered arrangement, that is, when the positions of the first electrode portion 35 and the second electrode portion 36 are correspondingly left and right, the portion where the solder ribbon is soldered is exactly falling between the two electrodes. When the finger electrodes 32 are between the portions, the two finger electrodes 32 cannot be electrically connected.

In the present invention, the first electrode portion 35 and the second electrode portion 36 are alternately arranged to connect the finger electrodes 32. Therefore, the first bus electrode 33 and the second bus electrode 34 are continuous with the finger electrodes 32. The conductive network can provide a continuous current conduction path by the first electrode portion 35 and the second electrode portion 36 even if the ribbon wire forms a dummy weld between any two finger electrodes 32. For example, if the ribbon wire on the first bus electrode 33 is soldered between the first and second finger electrodes 32, the first one The second finger electrode 32 can still be connected to the second electrode portion 36. This is a very innovative and practical structural design that is very helpful for industrial applications.

Referring to FIG. 4, the second preferred embodiment of the solar cell module of the present invention is substantially the same as the first preferred embodiment, except that the first bus electrode 33 and the second bus electrode 34 of the solar cell 3 are different. Structure.

The first segment 351 and the second segment 352 of the first bus electrode 33 of the embodiment, and the third segment 361 and the fourth segment 362 of the second bus electrode 34 not only connect the finger electrodes 32 or the outer finger electrodes 32', and also protrudes in the second direction 52 and spans the finger electrode 32 or the outer finger electrode 32' to which it is connected. This embodiment also achieves the same effects as the first preferred embodiment, and will not be described here.

Referring to FIG. 5, the third preferred embodiment of the solar cell module of the present invention is substantially the same as the first preferred embodiment, except that the first first electrode portion 35 of the embodiment is connected to an outer side. The finger electrode 32' and the two finger electrodes 32 are connected to each of the other first electrode portions 35 and each of the second electrode portions 36. This embodiment also achieves the same effects as the first preferred embodiment, and will not be described here.

It can be seen from the above three embodiments that the spirit of the present invention is that the positions of the first electrode portion 35 and the second electrode portion 36 in the first direction 51 must be shifted, and each of the finger electrodes 32 is connected to the first electrode portions. One of the 35 and one of the second electrode portions 36 to ensure that the conductive paths are continuous. However, the present invention does not need to define each of the first electrode portions 35 and each of the second electrodes. The number of the finger electrodes 32 connected to the pole portion 36 does not need to limit the shapes of the first electrode portion 35 and the second electrode portion 36. The shapes of the two electrode portions 35 may be the same or different, and of course, other shapes may be adopted. Other embodiments are described.

Referring to FIG. 6, the fourth preferred embodiment of the solar cell module of the present invention is substantially the same as the first preferred embodiment. The difference is that each of the first electrode portions 35 of the embodiment includes several A first line segment 354 that is continuously bent and connected. Each of the second electrode portions 36 includes a plurality of second line segments 364 that are connected in a continuous bend. The above design of the first electrode portion 35 can lengthen the extension thereof, increase the conductive path, and enable a sufficiently large contact area between the first electrode portion 35 and the substrate 31 to help increase the first electrode portion 35. Adhesion, while also providing sufficient welding bonding force for the ribbon conductor. Similarly, the structure of the second electrode portion 36 has the same effect.

Referring to FIG. 7, the fifth preferred embodiment of the solar cell module of the present invention is substantially the same as the first preferred embodiment. The difference is that each of the first electrode portions 35 of the embodiment includes a plurality of edges. The second direction 52 is spaced apart and both extend along the first direction 51, and a second conductive segment 356 extending along the second direction 52 and connecting the first conductive segments 355. Each of the second electrode portions 36 includes a plurality of third conductive segments 365 spaced along the second direction 52 and extending along the first direction 51, and a second conductive portion extending along the second direction 52 and connecting the third conductive portions The fourth conductive segment 366 of segment 365.

Each of the first electrode portions 35 of the embodiment can increase the conductive path of the first electrode portion 35 by the design of the first conductive segments 355, and can The first electrode portion 35 has a sufficiently large contact area with the substrate 31 to help increase the adhesion of the first electrode portion 35 to the substrate 31 and to provide sufficient solder bonding force for the ribbon conductor. Similarly, the structure of the second electrode portion 36 has the same effect.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

1‧‧‧ first plate

2‧‧‧Second plate

3‧‧‧Solar battery

31‧‧‧Substrate

311‧‧‧Stained surface

32‧‧‧ finger electrode

32'‧‧‧Outer finger electrodes

33‧‧‧First bus electrode

34‧‧‧Second bus electrode

35‧‧‧First electrode section

351‧‧‧ first paragraph

352‧‧‧second paragraph

353‧‧‧First junction

354‧‧‧First line segment

355‧‧‧First conductive segment

356‧‧‧Second conductive section

36‧‧‧Second electrode section

361‧‧‧ third paragraph

362‧‧‧ fourth paragraph

363‧‧‧Second junction

364‧‧‧second line

365‧‧‧third conductive section

366‧‧‧fourth conductive segment

4‧‧‧Package

51‧‧‧First direction

52‧‧‧second direction

D1~d6‧‧‧ length

1 is a partial cross-sectional view showing a first preferred embodiment of a solar cell module of the present invention; FIG. 2 is a top plan view of a solar cell of the first preferred embodiment; FIG. 3 is a partial enlarged view of FIG. 4 is a partial top plan view of a solar cell according to a second preferred embodiment of the solar cell module of the present invention; FIG. 5 is a partial view of a solar cell of a third preferred embodiment of the solar cell module of the present invention; FIG. 6 is a partial top plan view of a solar cell according to a fourth preferred embodiment of the solar cell module of the present invention; and FIG. 7 is a solar energy according to a fifth preferred embodiment of the solar cell module of the present invention. A partial top view of the battery.

3‧‧‧Solar battery

31‧‧‧Substrate

311‧‧‧Stained surface

32‧‧‧ finger electrode

32'‧‧‧Outer finger electrodes

33‧‧‧First bus electrode

34‧‧‧Second bus electrode

35‧‧‧First electrode section

36‧‧‧Second electrode section

51‧‧‧First direction

52‧‧‧second direction

Claims (6)

A solar cell comprising: a substrate having a light receiving surface; a plurality of finger electrodes on the light receiving surface and extending in a first direction, the finger electrodes along a second direction perpendicular to the first direction Arranging at intervals; a first bus electrode on the light receiving surface and including a plurality of first electrode portions arranged along the second direction; and a second bus electrode on the light receiving surface and along the first direction Arranging at intervals from the first bus electrode, the second bus electrode includes a plurality of second electrode portions spaced along the second direction, and the second electrode portions and the first electrode portions are in the first direction The positions are staggered; each finger electrode connects one of the first electrode portions and one of the second electrode portions. The solar cell of claim 1, wherein each of the first electrode portions includes a first segment and a second segment disposed opposite to each other in the second direction, each of the second electrode portions including the second electrode portion a third segment and a fourth segment disposed oppositely in a second direction; a third segment of the second electrode portion between any two adjacent first electrode portions and a second segment of one of the first electrode portions The same finger electrode is connected, and the fourth segment is connected to the same finger electrode as the first segment of the other first electrode portion. The solar cell of claim 2, wherein each of the first electrode portions further includes a first segment and the second segment a first connecting section, a length of the first segment along the first direction and a length of the second segment along the first direction are greater than a length of the first engaging segment along the first direction; each second electrode portion further Included in the second connecting segment between the third segment and the fourth segment, the length of the third segment along the first direction and the length of the fourth segment along the first direction are greater than the second connecting segment The length along the first direction. The solar cell of claim 1, wherein each of the first electrode portions includes a plurality of first line segments connected in a continuous bend; each of the second electrode portions includes a plurality of continuous bends The second line segment of the connection. The solar cell of claim 1, wherein each of the first electrode portions includes a plurality of first conductive segments spaced along the second direction and extending along the first direction, and a first along the first a second conductive segment extending in two directions and connecting the first conductive segments; each second electrode portion includes a plurality of third conductive segments spaced along the second direction and extending along the first direction, and an edge The second direction extends and connects the fourth conductive segments of the third conductive segments. A solar cell module comprising: a first plate and a second plate disposed opposite to each other; and a solar cell according to any one of claims 1 to 5, arranged on the first plate and the Between the second plates; and a packaging material between the first plate and the second plate, and wrapped around the solar cells.