TW201431096A - Solar battery, module thereof and manufacturing method thereof - Google Patents

Abstract

A solar cell, a module thereof and a method of manufacturing the same, the battery comprising: a battery body; and a first island electrode and a back electrode layer on the back surface of the battery body. The back electrode layer has an opening that partially overlaps the first island electrode. The minimum length of the first island electrode along a first direction is smaller than the minimum length of the opening along the first direction, and the minimum length of the first island electrode along a second direction is greater than the minimum of the opening along the second direction length. By the relative sizing between the first island electrode and the opening, the first island electrode can provide sufficient soldering area and solder joint strength for a solder bond to be firmly soldered.

Description

Solar battery, module thereof and manufacturing method thereof

The invention relates to a solar cell, a module thereof and a manufacturing method thereof, in particular to a twinned solar cell, a module thereof and a manufacturing method thereof.

Referring to Figures 1 and 2, a known twinned solar cell mainly comprises: a battery body 91 for converting light energy into electrical energy, and a front electrode (not shown) for conducting current and a back electrode 92. The back electrode 92 includes at least one bus bar electrode 93, and a back electrode layer 94 connected around the bus electrode 93 and covering the back surface of the battery body 91. There is a structural improvement of the bus electrode 93. The bus electrode 93 is formed to include a plurality of electrode portions 931 spaced along a first direction 95, thereby replacing the conventional elongated bus electrode to reduce the conductive paste of the electrode. Use the material and reduce the cost of the battery. In the manufacturing, the conductive paste of the bus electrode 93 is first coated by a screen printing method, and then the conductive paste of the back electrode layer 94 is coated, and the conductive paste is cured by a sintering process. Further, the bus electrode 93 and the back electrode layer 94 are formed.

When the solar cell is manufactured, a plurality of batteries are packaged into a battery module, and the package must be connected to adjacent batteries through a plurality of ribbons 96, which are connected to the front side of one of the batteries. The electrode is connected to the bus electrode 93 on the back side of the other battery to connect the batteries in series. However, since the back electrode layer 94 of the battery partially overlaps the surface of each electrode portion 931 of the bus electrode 93, in particular, the back electrode layer 94 covers the respective electrodes. The two ends of the pole portion 931 along the first direction 95 have a high height, which is not conducive to the soldering of the ribbon conductor 96, so that the contact surface of the bus electrode 93 can be in contact with the ribbon conductor 96 and the area for soldering is reduced. . For example, the thickness of the protruding portion 941 of the back electrode layer 94 shown in FIG. 2 is thicker, causing the local line segment 961 of the ribbon conductor 96 to be elevated and forming a gap 930 with the bus electrode 93, so that the ribbon conductor 96 The bus electrode 93 cannot be smoothly joined, and the welding bonding force between the two is reduced, resulting in a problem of insufficient joint strength, which affects product reliability.

Therefore, while saving the amount of conductive paste and reducing the production cost of the battery, how to improve the problem of insufficient joint strength is an important issue.

Accordingly, it is an object of the present invention to provide a solar cell, a module thereof and a method of manufacturing the same that can improve the bonding strength between the ribbon conductor and the bus electrode and reduce the production cost.

Therefore, the solar cell of the present invention comprises: a battery body having an opposite light receiving surface and a back surface, a front electrode on the light receiving surface, a first island electrode on the back surface, and a back surface covering the back surface a back electrode layer having an opening partially overlapping the first island electrode. The minimum length of the first island electrode along a first direction is greater than the minimum length of the first island electrode along a second direction perpendicular to the first direction, the first island electrode along the first direction The minimum length is less than a minimum length of the opening along the first direction, and a minimum length of the first island electrode along the second direction is greater than a minimum length of the opening along the second direction.

The solar cell module of the invention comprises: a first board oppositely disposed And a second plate, a plurality of solar cells, a plurality of ribbon leads, and a package as described above and arranged between the first plate and the second plate. The strip conductors respectively connect the first island electrodes of one of the two adjacent solar cells to the front electrode of the other. The encapsulant is located between the first plate and the second plate and is wrapped around the solar cells.

The method for manufacturing a solar cell of the present invention comprises: providing a battery body having an opposite light receiving surface and a back surface; forming a front electrode on the light receiving surface; and forming a first island electrode and a cover on the back surface The back electrode layer of the back surface has an opening partially overlapping the first island electrode.

The minimum length of the first island electrode along a first direction is greater than the minimum length of the first island electrode along a second direction perpendicular to the first direction, the first island electrode along the first direction The minimum length is less than a minimum length of the opening along the first direction, and a minimum length of the first island electrode along the second direction is greater than a minimum length of the opening along the second direction.

The invention also provides another solar cell, a module thereof and a method of manufacturing the same.

Another solar cell of the present invention comprises: a battery body having an opposite light receiving surface and a back surface, a front electrode on the light receiving surface, a first island electrode on the back surface, and a back surface a second island electrode spaced apart from the first island electrode in a first direction, and a back electrode layer covering the back surface, the back electrode layer having a first An opening in which the island electrode and the second island electrode partially overlap each other.

Another solar cell module of the present invention comprises: a first plate and a second plate disposed opposite to each other, a plurality of solar cells arranged as described above and arranged between the first plate and the second plate, and a plurality of welding With wire, and a package. The strip conductors respectively connect the first island electrode, the second island electrode and the other front electrode of one of the two adjacent solar cells. The encapsulant is located between the first plate and the second plate and is wrapped around the solar cells.

Another method for manufacturing a solar cell of the present invention comprises: providing a battery body having opposite light receiving surfaces and a back surface; forming a front electrode on the light receiving surface; and forming a first island electrode on the back surface a second island electrode spaced apart from the first island electrode in a first direction, and a back electrode layer covering the back surface, the back electrode layer having a first island electrode and a second island The openings of the electrodes are partially overlapped.

The effect of the invention is that the relative size between the first island electrode and the opening of the back electrode layer is designed, or by the relative size between the first island electrode and the second island electrode and the opening The island electrodes are not shielded on both sides in the first direction to provide sufficient soldering area and solder joint strength, and the product has good reliability.

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 to be noted that In the following description, similar elements are denoted by the same reference numerals.

Referring to FIG. 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 and the first a solar cell 3 between two plates 2, a plurality of ribbons 4 for connecting two adjacent solar cells 3, and at least one between the first plate 1 and the second plate 2 and coated A package 5 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 strip conductors 4 of the present embodiment are in groups of two, and each of the two strip conductors 4 connects the front side of one of the solar cells 3 to the back side of the adjacent other solar cell 3. The material of the encapsulant 5 is, for example, a translucent ethylene vinyl acetate copolymer (EVA). Of course, other materials suitable for packaging may be used.

The configurations of the solar cells 3 are the same, and only one of them will be described below as an example.

Referring to FIGS. 4-7, the solar cell 3 includes a battery body 31, a front electrode 32, a plurality of first island electrodes 33, and a back electrode layer 34.

The battery body 31 includes a substrate 311 having an opposite light receiving surface 312 and a back surface 313, an inner emitter layer 314 formed on the light receiving surface 312 of the substrate 311, and a light receiving surface 312. It also corresponds to the anti-reflection layer 315 on the emitter layer 314. The substrate 311 is, for example, a germanium substrate, and one of the substrate 311 and the emitter layer 314 is an n-type semiconductor, and the other is a p-type semiconductor, thereby forming a pn junction. The material of the antireflective layer 315, for example, silicon nitride (SiN _x), can be used to reduce reflected light to increase the amount of incident light.

The front surface electrode 32 is located on the light receiving surface 312 of the battery body 31, specifically, the anti-reflection layer 315 and contacts the light receiving surface 312. Since the front electrode 32 is not a modification of the present invention, it will not be described in detail.

The first island electrodes 33 are located on the back surface 313 and are arranged in two rows. The first island electrodes 33 arranged in the same row in the first direction 61 together form a bus electrode 330. Two bus electrodes 330 are formed, which are arranged in a second direction 62 perpendicular to the first direction 61.

The minimum length a1 of each of the first island electrodes 33 along the first direction 61 is greater than the minimum length a2 of the first island electrodes 33 along the second direction 62. Specifically, the first island electrode 33 of the present embodiment has a rectangular shape, and its longitudinal direction is parallel to the first direction 61. The "island electrode" according to the present invention is for explaining the arrangement between the first island electrodes 33, and is not for defining the shape of the first island electrode 33. The island shape may include a square and a circle. Shapes, semicircles, ovals, polygons, etc.

The back electrode layer 34 covers the back surface 313 and a portion of each of the first island electrodes 33, specifically covering opposite sides of each of the first island electrodes 33 along the second direction 62. The back electrode layer 34 has a plurality of openings 340 partially overlapping the first island electrodes 33. Each of the openings 340 of the present embodiment has a one-to-one correspondence with the first island electrodes 33. The structures of the openings 340 are the same, and the structures of the first island electrodes 33 are also the same, and then only the corresponding one of the openings 340 and the first one The island electrode 33 will be described.

The minimum length a1 of the first island electrode 33 along the first direction 61 is smaller than the minimum length b1 of the opening 340 along the first direction 61. The minimum length a2 of the first island electrode 33 along the second direction 62 is greater than the minimum length b2 of the opening 340 along the second direction 62. Preferably, the difference between a2 and b2 (i.e., twice the d2 indicated in Fig. 5) is 0.1 mm to 1.2 mm, in order to consider the screen printing difference between the first island electrode 33 and the back electrode layer 34.

More specifically, the first island electrode 33 has a first electrode body portion 331 overlapping with a partial portion of the opening 340, and two second electrodes 62 connected to the first electrode body portion 331 along the second direction 62. The first electrode extensions 332 of the opposite sides may have the same or different shapes, and the first electrode extensions 332 do not overlap with the openings 340; and the aforementioned d2 (FIG. 5) It corresponds to the minimum length of each of the first electrode extensions 332 in the second direction 62. The opening 340 has an opening body portion 341 overlapping the first electrode body portion 331 and two opening portions 342 respectively connected to opposite sides of the first body 61 of the opening body portion 341. The shape of the extensions 342 may be the same or different. The opening extensions 342 do not overlap the first island electrodes 33. The minimum length d1 of each opening extension 342 in the first direction 61 is greater than zero and less than or equal to 0.4 mm.

Since the two bus electrodes 330 formed by the first island electrodes 33 are weldably coupled to two of the ribbon wires 4 corresponding to the solar cells 3, the ribbon wires 4 are respectively connected to two adjacent ones. The first island electrode 33 of one of the solar cells 3 and the front electrode 32 of the other, Thereby, adjacent batteries are connected in series. The present invention provides the opening extension portion 342 which is not overlapped with the first island electrode 33 such that the length a1 is smaller than the length b1, mainly for the first island electrode 33 on both sides of the first direction 61. Preferably, the length d1 must be greater than 0, so that the entire length of the first island electrode 33 in the first direction 61 can be exposed and can be soldered. The wire 4 is contacted to provide good joint strength. Comparing Fig. 7 of the present invention with Fig. 2 of the prior art, it is also known that the present invention can reduce or even eliminate the gap 930 of Fig. 2. When the length d1 is larger than 4 mm, there is no more benefit for improving the joint strength, so the length d1 is preferably less than or equal to 0.4 mm. Moreover, the minimum length d2 of each of the first electrode extensions 332 in the second direction 62 is preferably greater than 0.3 mm, in order to account for the screen printing tolerance. The back electrode layer 34 and the first island electrodes 33 overlap in a certain area or more in the second direction 62 to electrically connect the back electrode layer 34 and the first island electrodes 33.

It is additionally noted that for each opening 340, the minimum length d1 of the two opening extensions 342 may be the same or different. For each of the first island electrodes 33, the minimum length d2 of the two first electrode extensions 332 may be the same or different. The minimum length of each element described in the present invention is mainly that when the element is in an irregular shape, the length is not uniform, and therefore the minimum length is taken. Of course, if the element has a regular shape, the length of each part of the element is fixed. In addition, although the number of the first island electrodes 33 and the openings 340 of the present embodiment are several, in practice, the spirit of the present invention mainly improves the dimensional relationship between the first island electrodes 33 and the openings 340. The number is not limited.

Referring to Figures 5-8, a first preferred embodiment of a method of fabricating a solar cell of the present invention comprises:

(1) Step 71: Providing the battery body 31, the emitter layer 314 is formed by a diffusion process mainly at the light receiving surface 312, and the antireflection layer 315 is formed on the emitter layer 314 by vacuum plating or the like. . The vacuum coating method of the present invention comprises physical vapor deposition (PVD), chemical vapor deposition (CVD), etc., and the chemical vapor deposition comprises PECVD.

(2) Step 72: forming the front surface electrode 32 on the light receiving surface 312. In this step, the conductive paste of the front surface electrode 32 is coated on the anti-reflective layer 315 by screen printing, followed by high temperature sintering. The conductive paste erodes and passes through the anti-reflective layer 315 to contact the emitter layer 314, and the front electrode 32 is formed when the conductive paste is cured.

(3) Step 73: The first island electrodes 33 and the back electrode layer 34 are formed on the back surface 313. In this step, the first island electrodes 33 are formed first, and then the back electrode layer 34 is formed. The first island electrodes 33 can be screen printed on the back surface 313 of the battery body 31. The conductive paste is coated with a conductive paste, and the slurry of the first island electrode 33, for example, a silver paste, is baked, and then the conductive paste of the back electrode layer 34 is coated on the back surface 313 by screen printing, for example, aluminum. The slurry is finally sintered by high temperature to complete the fabrication of the first island electrodes 33 and the back electrode layer 34. Of course, the length and distance of the first island electrodes 33 formed in this step and the openings 340 of the back electrode layer 34 are designed to meet the foregoing definitions herein, and will not be described here. In addition, the order of step 73 and step 72 can be adjusted. change.

In summary, by the cooperation design between the first island electrodes 33 and the corresponding openings 340, the first island electrodes 33 can be exposed at both ends in the longitudinal direction thereof, that is, the first island shape The electrodes 33 are exposed at both ends in the extending direction of the strip conductor 4 to provide a sufficient soldering area to firmly bond the strip conductors 4 to improve product reliability, and the bus electrode 330 of the present invention is spaced at intervals. The first island electrode 33 replaces the traditional elongated bus electrode, which can save the amount of conductive paste, thereby reducing the production cost of the battery and the module.

Referring to Figures 9 and 10, a second preferred embodiment of the solar cell module of the present invention is substantially the same as the structure of the first preferred embodiment, and the difference is mainly in the back electrode of the solar cell 3 of the present embodiment. Each opening 340 of layer 34 simultaneously partially overlaps the two island electrodes, respectively.

The back surface of the solar cell 3 of the present embodiment includes a plurality of second island electrodes 35 in addition to the plurality of first island electrodes 33. The first island electrodes 33 are spaced apart from the second island electrodes 35 and cooperate to form two bus electrodes 330 extending along the first direction 61, and the bus electrodes 330 are spaced along the second direction 62. arrangement. The first island electrode 33 and the second island electrode 35 of each of the bus electrodes 330 are staggered along the first direction 61, and an adjacent one of the first island electrodes 33 and one of each of the bus electrodes 330 The two island electrodes 35 collectively form an electrode group 350.

The back electrode layer 34 of the present embodiment has a plurality of openings 340 corresponding to the electrode groups 350, and each opening 340 and the first island electrode 33 and the second island shape of the electrode group 350 corresponding thereto Electrode 35 separate The portions are overlapped, so that the two side edges of the first island electrode 33 and the second island electrode 35 in the first direction 61 are not covered, thereby providing a sufficient soldering area of the ribbon conductor to ensure product reliability. Preferably, the embodiment also has the advantages of saving slurry and reducing production cost.

The opening 340 and the electrode group 350 corresponding to one of the groups are next described.

The first island electrode 33 includes a first electrode body portion 331 overlapping a partial portion of the opening 340, and two opposite sides of the first electrode body portion 331 along the opposite sides of the second direction 62. The shape of the first electrode extensions 332 may be the same or different, and the first electrode extensions 332 do not overlap the openings 340. The second island electrode 35 includes a second electrode body portion 351 overlapping with a partial portion of the opening 340, and two opposite sides of the second electrode body portion 351 which are respectively connected to opposite sides of the second direction 62. The two electrode extensions 352 do not overlap the openings 340. The shapes of the second electrode extensions 352 may be the same or different.

The opening 340 includes a first opening body portion 343 and a second opening body portion 344 which are respectively overlapped with the first electrode body portion 331 and the second electrode body portion 351, and are respectively connected to the first opening body portion 343. The first opening extensions 345 along the opposite sides of the first direction 61 are respectively connected to the second opening extensions 346 of the second opening body portion 344 on opposite sides of the first direction 61, and An engaging portion 347 connected between the adjacent first opening extending portion 345 and the second opening extending portion 346, the length of the engaging portion 347 along the second direction 62 is from the first direction thereof The opposite sides of 61 gradually narrow toward the center. The minimum length of the engaging portion 347 along the second direction 62 is smaller than the minimum length b2 of the first opening body portion 343 and the second opening body portion 344 along the second direction 62.

The shapes of the first opening extensions 345 may be the same or different, and the shapes of the second opening extensions 346 may be the same or different. The shapes of the first opening extension 345 and the second opening extension 346 may also be the same or different.

The minimum length d3 of each of the first opening extensions 345 in the first direction 61 is greater than 0 and less than or equal to 0.4 mm. The minimum length d4 of each second opening extension 346 in the first direction 61 is greater than zero and less than or equal to 0.4 mm. The two d3 of each opening may be the same or different, and the two d4 of each opening 340 may also be the same or different. And d3 and d4 can be the same or different.

The minimum lengths a2 and c2 of the first island electrode 33 and the second island electrode 35 along the second direction 62 are greater than the first opening body portion 343 and the second opening body portion 344 along the second direction. The minimum length of 62 is b2. Preferably, the difference between a2 and b2 is 0.1 mm to 1.2 mm, and the difference between c2 and b2 is 0.1 mm to 1.2 mm.

Specifically, the minimum length d2 of each of the first electrode extensions 332 in the second direction 62 is preferably greater than 0.3 mm, and the minimum length d5 of each of the second electrode extensions 352 in the second direction 62 is greater. Good ground is greater than 0.3mm. The two d2 of the first island electrode 33 may be the same or different, and the two d5s of the second island electrode 35 may be the same or different. And d5 and d2 can also be the same or different.

It should be noted that the structure of the first island electrode 33 and the second island electrode 35 may be the same or different. The strip conductors in the battery module must respectively connect the first island electrodes 33, the second island electrodes 35 of one of the two adjacent solar cells 3, and the front electrodes of the other battery.

The main difference between this embodiment and the first preferred embodiment lies in the correspondence between the first opening 340 and the electrodes. However, the same function as the first preferred embodiment can be achieved in this embodiment, and will not be described here.

The method for manufacturing the battery of the present embodiment is substantially the same as the method for the first preferred embodiment. Only the steps of the embodiment are briefly described below, and the details thereof are not described in detail. The method of this embodiment includes:

(1) The battery body 31 is provided.

(2) The front surface electrode is formed on the light receiving surface of the battery body 31.

(3) forming the first island electrodes 33, the second island electrodes 35 on the back surface of the battery body 31, and the back electrode layer 34 covering the back surface, each opening of the back electrode layer 34 340 and the first island electrode 33 and the second island electrode 35 in each electrode group 350 partially overlap each other. The first island electrode 33 and the second island electrode 35 may be formed first, and then the back electrode layer 34 may be formed. That is, the conductive paste covering the first island electrode 33 and the second island electrode 35 may be screen printed first, and then the conductive paste of the back electrode layer 34 may be overlaid. Certainly, the relative length and distance design of the first island electrodes 33, the second island electrodes 35 and the openings 340 of the back electrode layer 34 formed in this step are required to meet the foregoing definitions, and are not described here. .

The manufacturing method of this embodiment is substantially the same as the first preferred embodiment. In the same manner, the screen structure for printing the back electrode layer 34 in this embodiment can be changed.

In this embodiment, the engaging portion 347 of the opening 340 is designed to be narrowed, so that the conductive area of the back electrode layer 34 is increased, and the current collecting efficiency can be improved.

Referring to FIG. 11, a third preferred embodiment of the solar cell module of the present invention is substantially the same as the second preferred embodiment. The difference is that each part of the opening 340 of the embodiment is along the second direction 62. The length of the opening 340 is adjacent to the first opening extension 345 and is connected to the second opening extension 346.

The minimum lengths a2 and c2 of the first island electrode 33 and the second island electrode 35 in the second direction 62 of the embodiment are both greater than the minimum length b2 of the opening 340 along the second direction 62. Preferably, the difference between a2 and b2 is 0.1 mm to 1.2 mm, and the difference between c2 and b2 is 0.1 mm to 1.2 mm.

The manufacturing method of this embodiment is the same as the second preferred embodiment except that a different screen is necessary to form the back electrode layer 34.

Referring to FIG. 12, a fourth preferred embodiment of the solar cell module of the present invention is different from the second preferred embodiment in that the engaging portion 347 of the opening 340 of the present embodiment is approximately square. The minimum length of the engaging portion 347 of the present embodiment along the second direction 62 is also smaller than the minimum length of the first opening body portion 343 and the second opening body portion 344 along the second direction 62.

Referring to FIG. 13, a fifth preferred embodiment of the solar cell module of the present invention is different from the second preferred embodiment in that the shape of the connecting portion 347 of the opening 340 of the present embodiment is irregular, but Example title The minimum length of the joint portion 347 along the second direction 62 is also smaller than the minimum length of the first opening body portion 343 and the second opening body portion 344 along the second direction 62.

Referring to Fig. 14, a sixth preferred embodiment of the solar cell module of the present invention is substantially the same as the second preferred embodiment, and the following mainly describes different places.

The back surface of the battery of this embodiment is also formed with two bus electrodes 330 arranged in the second direction 62. The island electrodes in each of the bus electrodes 330 include a first island electrode 33, a first island. The second island electrodes 35 are arranged along the first direction 61, and N are located on the back surface and are spaced apart from the first island electrode 33 and the second island electrode 35 along the first direction 61. The third island electrode 36, wherein N is an integer greater than or equal to 1. The back electrode layer 34 of the present embodiment has two openings 340 respectively corresponding to the bus electrodes 330, each opening 340 extending along the first direction 61 and corresponding to the first island shape in the bus electrode 330 The electrode 33, the second island electrode 35, and the N third island electrodes 36 partially overlap each other. The spirit of this embodiment is mainly that each of the bus electrodes 330 may be provided with only one opening 340 to correspond to all the island electrodes in the bus electrode 330. Also, similarly, each of the island electrodes is not covered by the back electrode layer 34 along both side edges in the first direction 61, thereby providing sufficient soldering area and bonding strength.

The structures of the first island electrode 33, the second island electrode 35, and the third island electrode 36 of the present embodiment may be the same or different. The manufacturing method of this embodiment is substantially the same as the second preferred embodiment except that the battery body is The first island electrode 33, the second island electrode 35, and the N third island electrodes 36 must be formed on the back surface, and a different screen must be used to form the back electrode layer 34.

It is to be noted that the shape of the joint portion of the opening 340 between any two adjacent first island electrodes 33 of the present embodiment may also be as in the foregoing second, fourth and fifth embodiments (Figs. 10, 12, 13). ) The shape.

Referring to FIG. 15, a seventh preferred embodiment of the solar cell module of the present invention is substantially the same as the first preferred embodiment, but each opening 340 of the embodiment has an opening body portion 341 and two openings. In addition to the extending portion 342, there are two protruding portions 348 spaced along the first direction 61 and connected to one side of the opening extending portions 342. The protruding portion 348 of the embodiment is substantially triangular, but may be implemented. For other shapes.

Any two adjacent openings 340 of this embodiment are not connected, so that the opposing projections 348 of any two adjacent openings 340 are not in contact. However, each opening 340 can also be connected by a protrusion 348 during implementation.

Referring to FIG. 16, an eighth preferred embodiment of the solar cell module of the present invention is different from the seventh preferred embodiment in that each of the protrusions 348 of the opening 340 of the present embodiment is arcuate and has one end edge. Extends in an arc.

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‧‧‧ battery body

311‧‧‧Substrate

312‧‧‧Stained surface

313‧‧‧Back

314‧‧ ‧ emitter layer

315‧‧‧Anti-reflective layer

32‧‧‧ front electrode

33‧‧‧First island electrode

330‧‧‧Concurrent electrode

331‧‧‧First electrode body

332‧‧‧First electrode extension

34‧‧‧Back electrode layer

340‧‧‧ openings

341‧‧‧Open body

342‧‧‧ Opening extension

343‧‧‧First opening body

344‧‧‧Second opening body

345‧‧‧First opening extension

346‧‧‧Second opening extension

347‧‧‧Connecting Department

348‧‧‧Protruding

35‧‧‧Second island electrode

350‧‧‧electrode group

351‧‧‧Second electrode body

352‧‧‧Second electrode extension

36‧‧‧The third island electrode

4‧‧‧welding wire

5‧‧‧Package

61‧‧‧First direction

62‧‧‧second direction

71~73‧‧‧Steps

A1, a2, b1, b2, c2‧‧‧ length

D1~d5‧‧‧ length

Figure 1 is a schematic rear view of a known solar cell; 2 is a rear cross-sectional view of the solar cell taken along line AA of FIG. 1, and illustrates a solder ribbon connected to a bus electrode of the solar cell; FIG. 3 is a solar cell module of the present invention. Figure 4 is a schematic side view of a solar cell of the first preferred embodiment; Figure 5 is a partial enlarged view of Figure 4; Figure 6 is taken along line BB of Figure 4 Figure 7 is a cross-sectional view taken along line CC of Figure 4, showing a solder ribbon connected to a first island electrode of the solar cell; Figure 8 is a manufacturing method of the solar cell of the present invention FIG. 9 is a schematic rear view of a solar cell according to a second preferred embodiment of the solar cell module of the present invention; FIG. 10 is a partial enlarged view of FIG. 9; FIG. 12 is a schematic partial rear view of a solar cell according to a fourth preferred embodiment of the solar cell module of the present invention; FIG. 13 is a partial schematic view of a solar cell of a solar cell module according to a fourth preferred embodiment of the present invention; this invention A partial schematic view of the back surface of the solar cell module one solar energy cell fifth preferred embodiment; FIG. 14 is a schematic view of a solar cell back surface of one solar cell module of the present invention, a sixth preferred embodiment; 15 is a schematic partial rear view of a solar cell according to a seventh preferred embodiment of the solar cell module of the present invention; and FIG. 16 is a rear view of a solar cell according to an eighth preferred embodiment of the solar cell module of the present invention; Partial schematic.

3‧‧‧Solar battery

33‧‧‧First island electrode

331‧‧‧First electrode body

332‧‧‧First electrode extension

34‧‧‧Back electrode layer

340‧‧‧ openings

341‧‧‧Open body

342‧‧‧ Opening extension

61‧‧‧First direction

62‧‧‧second direction

A1, a2, b1, b2, d1, d2‧‧‧ length

Claims (26)

A solar cell comprising: a battery body having an opposite light receiving surface and a back surface; a front electrode on the light receiving surface; a first island electrode on the back surface; and a back electrode layer covering the a back surface and having an opening partially overlapping the first island electrode; wherein a minimum length of the first island electrode along a first direction is greater than a second length of the first island electrode along a vertical direction a minimum length of the first island-shaped electrode in the first direction is smaller than a minimum length of the opening in the first direction, and a minimum length of the first island-shaped electrode in the second direction is greater than the opening along the The minimum length in the second direction. The solar cell of claim 1, wherein a difference between a minimum length of the first island electrode in the second direction and a minimum length of the opening along the second direction is 0.1 mm to 1.2 mm. The solar cell of claim 1, wherein the first island electrode comprises a first electrode body portion, the opening has an opening body portion overlapping the first electrode body portion, and two separate connections And an opening extension of the opening body portion on opposite sides of the first direction, a minimum length of each opening extension in the first direction being greater than 0 and less than or equal to 0.4 mm. The solar cell of claim 3, wherein the first island electrode further has two wires respectively connected to the first electrode body portion. a first electrode extension along opposite sides of the second direction. 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 4, arranged on the first plate and the Between the second plates; a plurality of strip conductors respectively connecting the first island electrodes of one of the two adjacent solar cells and the front electrode of the other; and a package material located at the first plate and the Between the second plates, and wrapped around the solar cells. A method of manufacturing a solar cell, comprising: providing a battery body having an opposite light receiving surface and a back surface; forming a front electrode on the light receiving surface; and forming a first island electrode on the back surface and covering the surface a back electrode layer of the back surface, the back electrode layer having an opening partially overlapping the first island electrode; wherein a minimum length of the first island electrode along a first direction is greater than a vertical direction of the first island electrode a minimum length of the second direction of the first direction, a minimum length of the first island electrode along the first direction is smaller than a minimum length of the opening along the first direction, the first island electrode along the second direction The minimum length is greater than the minimum length of the opening in the second direction. The method of manufacturing a solar cell according to claim 6, wherein the first island electrode is formed first and then the back electrode layer is formed. The method for manufacturing a solar cell according to claim 6, wherein a difference between a minimum length of the first island electrode in the second direction and a minimum length of the opening along the second direction is 0.1 mm. 1.2mm. The method of manufacturing a solar cell according to the sixth aspect of the invention, wherein the first island electrode comprises a first electrode body portion, the opening having an opening body portion overlapping the first electrode body portion, and And an opening extension respectively connected to opposite sides of the opening body portion along the first direction, wherein the minimum length of each opening extension in the first direction is greater than 0 and less than or equal to 0.4 mm. The method of manufacturing a solar cell according to claim 9, wherein the first island electrode further has two first electrodes respectively connected to opposite sides of the first electrode body portion along the second direction. Extension. A solar cell comprising: a battery body having an opposite light receiving surface and a back surface; a front electrode on the light receiving surface; a first island electrode on the back surface; and a second island electrode located at The back surface is spaced apart from the first island electrode in a first direction; and a back electrode layer covers the back surface and has a partial overlap with the first island electrode and the second island electrode respectively Opening. The solar cell of claim 11, wherein the first island electrode and the second island electrode are perpendicular to the first direction The minimum length in the second direction is greater than the minimum length of the opening in the second direction. The solar cell of claim 11, wherein the first island electrode comprises a first electrode body portion, and the second island electrode comprises a second electrode body portion; the opening comprises a first opening body portion and a second opening body portion of the first electrode body portion and the second opening body portion are respectively connected to the first sides of the first opening body portion on opposite sides of the first direction An opening extension portion, two second opening portions respectively connected to opposite sides of the second opening body portion along the first direction, and a first opening extending portion and the second opening extending adjacent to each other And a minimum length of the connecting portion in a second direction perpendicular to the first direction is smaller than a minimum length of the first opening body portion and the second opening body portion in the second direction. The solar cell of claim 13, wherein a minimum length of each of the first opening extensions and each of the second opening extensions in the first direction is greater than 0 and less than or equal to 0.4 mm. The solar cell of claim 14, wherein the first island electrode further comprises two first electrode extensions respectively connected to opposite sides of the first electrode body portion along the second direction; The second island electrode further includes two second electrode extensions respectively connected to opposite sides of the second electrode body portion along the second direction. The solar cell of claim 11, wherein a difference between a minimum length of the first island electrode in a second direction perpendicular to the first direction and a minimum length of the opening along the second direction is 0.1mm~ 1.2 mm; a difference between a minimum length of the second island electrode in the second direction and a minimum length of the opening along the second direction is 0.1 mm to 1.2 mm. The solar cell of claim 11, further comprising N third island electrodes located on the back surface and spaced apart from the first island electrode and the second island electrode in the first direction, N is an integer greater than or equal to 1, and the opening of the back electrode layer partially overlaps the first island electrode, the second island electrode, and the N third island electrodes, respectively. 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 11 to 17, arranged on the first plate and the Between the second plates; a plurality of strip conductors respectively connecting the first island electrode, the second island electrode and the other front electrode of one of the two adjacent solar cells; and a package material, located The first plate and the second plate are wrapped around the solar cells. A method of manufacturing a solar cell, comprising: providing a battery body having an opposite light receiving surface and a back surface; forming a front electrode on the light receiving surface; and forming a first island electrode on the back surface a second island electrode arranged in a first direction from the first island electrode, and a back electrode layer covering the back surface, the back electrode layer having a first island shape An opening in which the pole and the second island electrode are partially overlapped, respectively. The method of manufacturing a solar cell according to claim 19, wherein the first island electrode and the second island electrode are formed first, and then the back electrode layer is formed. The method for manufacturing a solar cell according to claim 19, wherein a minimum length of the first island electrode and the second island electrode in a second direction perpendicular to the first direction is greater than the opening edge The minimum length of the second direction. The method of manufacturing a solar cell according to claim 19, wherein the first island electrode comprises a first electrode body portion, and the second island electrode comprises a second electrode body portion; the opening comprises respectively a first opening body portion and a second opening body portion overlapping the first electrode body portion and the second electrode body portion are respectively connected to opposite sides of the first opening body portion along the first direction a first opening extension portion, two second opening portions respectively connected to opposite sides of the second opening body portion along the first direction, and a first opening extending portion adjacent to the first opening body portion and the first opening And a connecting portion between the two opening extensions, the minimum length of the engaging portion in a second direction perpendicular to the first direction is smaller than a minimum length of the first opening body portion and the second opening body portion in the second direction. The method of manufacturing a solar cell according to claim 22, wherein a minimum length of each of the first opening extensions and each of the second opening extensions in the first direction is greater than 0 and less than or equal to 0.4 mm. . Solar cell manufacturing method according to claim 23 The first island electrode further includes two first electrode extensions respectively connected to opposite sides of the first electrode body portion along the second direction; the second island electrode further includes two connected to the first electrode a second electrode extension portion of the second electrode body portion on opposite sides of the second direction. The method of manufacturing a solar cell according to claim 19, wherein the first island electrode has a minimum length along a second direction perpendicular to the first direction and a minimum length of the opening along the second direction The difference is 0.1 mm to 1.2 mm; the difference between the minimum length of the second island electrode in the second direction and the minimum length of the opening along the second direction is 0.1 mm to 1.2 mm. The method for manufacturing a solar cell according to claim 19, wherein N and N of the first island electrode and the second island electrode are arranged along the first direction on the back surface of the battery body. The third island electrode, wherein N is an integer greater than or equal to 1, the opening of the back electrode layer and the first island electrode, the second island electrode and the N third island electrodes are respectively partially localized overlapping.