U.S. patent application number 17/666271 was filed with the patent office on 2022-05-19 for solar cell module.
This patent application is currently assigned to LG ELECTRONICS INC.. The applicant listed for this patent is LG ELECTRONICS INC.. Invention is credited to Jinsung KIM.
Application Number | 20220158017 17/666271 |
Document ID | / |
Family ID | 1000006125207 |
Filed Date | 2022-05-19 |
United States Patent
Application |
20220158017 |
Kind Code |
A1 |
KIM; Jinsung |
May 19, 2022 |
SOLAR CELL MODULE
Abstract
A solar cell module includes a plurality of solar cells each
having a long axis and a short axis, and including a first
electrode disposed on a front surface of a substrate and a second
electrode disposed on a back surface of the substrate. The solar
cells are disposed along a first direction. The solar cell module
further includes a plurality of wiring members connected to the
first electrode of a first solar cell and the second electrode of a
second solar cell, wherein the plurality of wiring members includes
a core layer of metal, and a solder layer formed of a solder
material. Further, a ratio of a thickness of the solder layer to a
thickness of the core layer is approximately 0.05 to 0.08, and a
distance between the first solar cell and the second solar cell is
approximately 0.5 mm to 1.5 mm.
Inventors: |
KIM; Jinsung; (Seoul,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG ELECTRONICS INC. |
Seoul |
|
KR |
|
|
Assignee: |
LG ELECTRONICS INC.
Seoul
KR
|
Family ID: |
1000006125207 |
Appl. No.: |
17/666271 |
Filed: |
February 7, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
16677211 |
Nov 7, 2019 |
11264523 |
|
|
17666271 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 31/0512 20130101;
H01L 31/0201 20130101; H01L 31/049 20141201 |
International
Class: |
H01L 31/05 20060101
H01L031/05; H01L 31/049 20060101 H01L031/049; H01L 31/02 20060101
H01L031/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 7, 2018 |
KR |
10-2018-0136201 |
Claims
1. A solar cell module, comprising: a plurality of solar cells each
having a rectangular shape including a long axis and a short axis,
each of the plurality of solar cells including a first electrode
disposed on a front surface of a substrate and a second electrode
disposed on a back surface of the substrate, the plurality of solar
cells being disposed along one direction; and a plurality of wiring
members connected to the first electrode of a first solar cell and
the second electrode of a second solar cell adjacent to the first
solar cell among the plurality of solar cells, wherein the
plurality of wiring members include a core layer of metal, and a
solder layer which surrounds a surface of the core layer and is
formed of a solder material, wherein a ratio of a thickness of the
solder layer to a thickness of the core layer is approximately 0.05
to 0.08, and wherein a distance between the first solar cell and
the second solar cell is approximately 0.5 mm to 1.5 mm.
2. The solar cell module of claim 1, wherein the number of the
plurality of wiring members is about 8 to 12.
3. The solar cell module of claim 1, wherein a thickness of the
plurality of wiring members is approximately 270 .mu.m to 320
.mu.m.
4. The solar cell module of claim 1, wherein the plurality of
wiring members include a first portion attached at the first solar
cell, a second portion attached at the second solar cell, and a
third portion connecting the first portion and the second portion
between the first solar cell and the second solar cell, and wherein
the thickness of the solder layer of the third portion is less than
the thickness of the solder layer of the first portion and the
second portion attached at the first solar cell and the second
solar cell, respectively.
5. The solar cell module of claim 1, wherein the solder layer
includes a first part attached at the first electrode or the second
electrode and a second part opposite to the first part, and wherein
a thickness of the first part is greater than a thickness of the
second part.
6. The solar cell module of claim 1, wherein the plurality of
wiring members each has a wire-shape or has a rounded-shape.
7. The solar cell module of claim 1, wherein each of the plurality
of solar cells is a fragment divided from a mother solar cell.
8. The solar cell module of claim 7, wherein the mother solar cell
is divided into two fragments.
9. The solar cell module of claim 8, wherein each of the two
fragments includes a cut surface and a non-cut surface, and wherein
the plurality of wiring members extend across the non-cut surface
of one of the two fragments and across the cut surface of the other
of the two fragments when extending between the two fragments.
10. The solar cell module of claim 1, wherein the each of the
plurality of solar cells includes a cut surface and a non-cut
surface in the one direction, and wherein neighboring two solar
cells among the plurality of solar cells are disposed with the cut
surface of one of the neighboring two solar cells and the non-cut
surface of the other of the neighboring two solar cells facing each
other in the one direction.
11. The solar cell module of claim 1, wherein the first electrode
includes: a bus bar including a plurality of pads and disposed
along the short axis; and a plurality of finger lines disposed
along the long axis.
12. The solar cell module of claim 1, wherein the thickness of the
core layer is approximately 240 to 280 .mu.m.
13. The solar cell module of claim 12, wherein the thickness of the
core layer is approximately 255 to 265 .mu.m.
14. The solar cell module of claim 12, wherein the thickness of the
solder layer is approximately 15 .mu.m to 20 .mu.m.
15. The solar cell module of claim 1, wherein a cross section of at
least one of the plurality of wiring members has a polyhedral shape
having at least a curved surface or at least three vertices.
16. The solar cell module of claim 1, wherein the distance between
the first solar cell and the second solar cell is approximately 1
mm.
17. The solar cell module of claim 1, wherein the plurality of
wiring members extend along the short axis of each cell.
18. The solar cell module of claim 1, wherein the core layer
includes at least one of Ni, Cu, Ag and Al.
19. A solar cell module, comprising: a plurality of solar cells
each having a rectangular shape including a long axis and a short
axis, the plurality of solar cells being disposed along one
direction; and a plurality of wiring members connected to a front
surface of a first solar cell and a back surface of the second
solar cell adjacent to the first solar cell among the plurality of
solar cells, wherein the plurality of wiring members include a core
layer, and a solder layer which surrounds a surface of the core
layer, wherein a ratio of a thickness of the solder layer to a
thickness of the core layer is approximately 0.05 to 0.08, and
wherein a distance between the first solar cell and the second
solar cell is approximately 0.5 mm to 1.5 mm.
20. The solar cell module of claim 19, wherein the thickness of the
core layer is approximately 240 to 280 .mu.m, and wherein the
thickness of the solder layer is approximately 15 .mu.m to 20
.mu.m.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Divisional application of U.S. patent
application Ser. No. 16/677,211 filed on Nov. 7, 2019, which claims
priority to and the benefit of Korean Patent Application No.
10-2018-0136201 filed in the Korean Intellectual Property Office on
Nov. 7, 2018, the entire contents of all these applications are
hereby expressly incorporated by reference into the present
application.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present disclosure relates to a solar cell module in
which a plurality of solar cells are connected by a wiring
member.
Description of the Related Art
[0003] A plurality of solar cells are connected in series or in
parallel by ribbons, and are manufactured in a form of solar cell
panels by a packaging process for protecting the plurality of solar
cells.
[0004] Various methods can be used to connect the solar cells, for
example, it is possible to connect the solar cells using a ribbon
having a large width of about 1.5 mm. However, since losses of
light can occur due to the large width of the ribbon, the number of
ribbons disposed in the solar cell should be reduced. Then, moving
distances of carriers increase, so that the electrical
characteristics cannot be excellent.
[0005] Therefore, a structure of increasing the number of wiring
members and reducing the moving distances of the carriers by using
the wiring members having a width smaller than the ribbon instead
of the ribbon has been proposed.
[0006] By the way, since the wiring member is made of metal, it is
not easily bent or warped, when two neighboring solar cells are
connected with a plurality of wiring members, a distance between
the two neighboring solar cells can be widened. Thus, there is a
problem that the overall appearance size of the solar cell module
increases.
[0007] On the other hand, a new type of solar cell module has been
proposed in which a solar cell (hereinafter referred to as a mother
solar cell) produced in a standard size is divided into a plurality
of solar cells to form a solar cell module.
[0008] By the way, a solar cell module configured by using the
divided solar cells has a problem that the total size of the solar
cell panel increases, because the number of divided solar cells
used is multiple as many as the solar cell module made using the
mother solar cell.
[0009] As the size of the solar cell panel increases in this way,
because it is difficult for producers of the solar cells to use the
existing equipment, that is, the existing production equipment
installed to fit the solar cell panels made of the mother solar
cells, and thus new production equipment must be installed, there
is a problem that the price competitiveness of the product is
lowered due to the excessive production cost of the product.
[0010] Therefore, even when manufacturing the solar cell panel by
connecting the divided solar cells with the plurality of wiring
members, there is a need for a technology that can be used as it is
without changing the existing equipment.
SUMMARY OF THE INVENTION
[0011] The present disclosure has been made in view of the above
technical background, when connecting divided solar cells with a
plurality of wiring members, it is to prevent the size of the solar
panel from increasing by reducing a distance between the two
neighboring solar cells than before.
[0012] A solar cell module according to an embodiment of the
present disclosure includes a plurality of solar cells each having
a long axis and a short axis, and including a first electrode
disposed on a front surface and a second electrode disposed on a
back surface thereof, and the plurality of solar cells being
disposed along a first direction, and a plurality of wiring members
connected to the first electrode of a first solar cell and the
second electrode of a second solar cell adjacent to the first solar
cell among the plurality of solar cells, wherein the plurality of
wiring members include a core layer of metal, and a solder layer
which surrounds a surface of the core layer and is formed of a
solder material, and a ratio D2/D1 of a thickness D2 of the core
layer to a thickness D1 of the core layer is approximately
0.05<D2/D1<0.08.
[0013] A thickness of the plurality of wiring members can be 270
.mu.m to 320 .mu.m or approximately thereabout, for example the
thickness of the core layer can be 240 to 280 .mu.m or
approximately thereabout, for example 255 to 265 .mu.m or
approximately thereabout, and the thickness of the core layer can
be 15 .mu.m to 20 .mu.m or approximately thereabout.
[0014] A cross section of each wiring member can have a polyhedral
shape having at least a curved surface or at least three
vertices.
[0015] Preferably, a number of the plurality of wiring members can
be 6 to 24, for example the number of the plurality of wiring
members can be 8 to 12, and a distance between the first solar cell
and the second solar cell can be 0.5 mm to 1.5 mm, for example can
be 1 mm.
[0016] Preferably, the short axis can be a half of the long
axis.
[0017] Each of the plurality of solar cells can include a first
side in the first direction and a second side opposite to the first
side having a surface roughness rougher than the first side.
[0018] Each of the plurality of solar cells can include a first
side and a second side opposite to the first side having a surface
roughness rougher than the first side.
[0019] According to an embodiment of the present disclosure, when
composing a module using divided solar cells, the present
disclosure prevents the size of the module from increasing by
reducing the distance between the solar cells, in addition, the
present disclosure prevents the output of the solar cell module
from decreasing by optimizing the thickness of the wiring member to
match the reduced distance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view illustrating a solar cell panel
according to an embodiment of the present disclosure.
[0021] FIG. 2 is a cross-sectional view taken along a line II-II in
FIG. 1.
[0022] FIG. 3 is a perspective view illustrating a solar cell
module according to an embodiment of the present disclosure.
[0023] FIG. 4 is a cross-sectional view taken along a line IV-IV in
FIG. 3.
[0024] FIG. 5 is a perspective view showing an overall appearance
of a wiring member.
[0025] FIG. 6 is a plan view schematically showing a front surface
of a mother solar cell forming a half cut cell shown in FIG. 4.
[0026] FIG. 7 is a plan view illustrating a schematic view of a
solar cell module shown in FIG. 3.
[0027] FIG. 8 is a cross-sectional view taken along a line
VIII-VIII in FIG. 7.
[0028] FIGS. 9 and 10 are graphs showing simulation results of
outputs depending on the number of wiring members measured by
diameters, numbers of wiring members and distances between solar
cells as variables.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0029] Hereinafter, embodiments of the present disclosure will be
described in detail with reference to the accompanying drawings.
However, it is needless to say that the present disclosure is not
limited to these embodiments and can be modified into various
forms.
[0030] In the drawings, illustration of the parts not related to
the description is omitted in order to clarify and briefly describe
the present disclosure, and the same reference numerals are used
for the same or very similar parts throughout the specification. In
the drawings, the thickness, width, and the like are enlarged or
reduced to make the explanation more clear, and the thickness,
width, etc. of the present disclosure are not limited to those
shown in the drawings.
[0031] When a part is referred to as "including" another part
throughout the specification, it does not exclude other parts and
can further include other parts unless specifically stated
otherwise. Further, when a part of a layer, a film, a region, a
plate, or the like is referred to as being "on" other part, this
includes not only the case where it is "directly on" the other part
but also the case where the other part is positioned in the middle.
When the part of the layer, the film, the region, the plate, or the
like is referred to as being "directly on" the other part, it means
that no other part is positioned in the middle.
[0032] Hereinafter, a solar cell and a solar cell panel including
the solar cell according to an embodiment of the present disclosure
will be described in detail with reference to the accompanying
drawings. In the following, the expressions "first", "second",
"third", etc. are used only to distinguish each other, but the
present disclosure is not limited thereto.
[0033] FIG. 1 is a perspective view illustrating a solar cell panel
according to an embodiment of the present disclosure, and FIG. 2 is
a cross-sectional view taken along a line II-II in FIG. 1. All the
components of the solar cell panel according to all embodiments of
the present disclosure are operatively coupled and configured.
[0034] Referring to FIGS. 1 and 2, a solar cell panel 100 according
to the present embodiment includes a plurality of solar cells 150
and a wiring member (or a wire, an interconnector, etc.) 142 for
electrically connecting the plurality of solar cells 150 that form
a string NA. The solar cell panel 100 includes a sealing member 130
that surrounds and seals a solar cell module (MA) including the
plurality of solar cells 150 and the wiring member (or
interconnector) 142 connecting them, a first cover member 110
positioned on a front surface of the solar cell 150 on the sealing
member 130, and a second cover member 120 positioned on a back
surface of the solar cell 150 on the sealing member 130. This will
be explained in more detail.
[0035] First, the solar cell 150 can include a photoelectric
conversion unit that converts the solar cell into electric energy,
and an electrode that is electrically connected to the
photoelectric conversion unit to collects and transfers a current.
The plurality of solar cells 150 can be electrically connected in
series, parallel, or series-parallel by the wiring member 142.
Specifically, the wiring member 142 electrically connects two
neighboring solar cells 150 among the plurality of solar cells
150.
[0036] A bus ribbon 145 electrically connects two neighboring
strings among a plurality of strings that are bundles of solar
cells connected by the wiring member 142. The wiring member is
connected to one end of the string, and the bus ribbon 145 can
electrically connect two adjacent strings by connecting the wiring
member connected to one end of the string. The bus ribbon 145 can
be disposed in the direction crossing the string at the end of the
string. The bus ribbon 145 can connect strings adjacent to each
other or to a junction box that prevents reverse flow of current in
the string or strings. The material, shape, connection structure,
etc. of the bus ribbon 145 can be variously modified, and the
present disclosure is not limited thereto.
[0037] The sealing member 130 can include a first sealing member
131 positioned on the front surface of the solar cell 150 connected
by the wiring member 142, and a second sealing member 132
positioned on the back surface of the solar cell 150. The first
sealing member 131 and the second sealing member 132 prevent
moisture and oxygen from entering and chemically bind each element
of the solar cell panel 100. The first and second sealing members
131 and 132 can be made of an insulating material having
transparency and adhesiveness. For example, an ethylene-vinyl
acetate copolymer resin (EVA), a polyvinyl butyral, a silicon
resin, an ester-based resin, an olefin-based resin, or the like can
be used for the first sealing member 131 and the second sealing
member 132. The second cover member 120, the second sealing member
132, the solar cell 150, the first sealing member 131, and the
first cover member 110 are integrated to form the solar cell panel
100 by a lamination process or the like using the first and second
sealing members 131 and 132.
[0038] The first cover member 110 is positioned on the first
sealing member 131 to constitute the front surface of the solar
cell panel 100, and the second cover member 120 is positioned on
the second sealing member 132 to constitute the back surface of the
solar cell panel 100. The first cover member 110 and the second
cover member 120 can be made of an insulating material capable of
protecting the solar cell 150 from external shock, moisture,
ultraviolet rays, or the like. The first cover member 110 can be
made of a light penetrating material capable of penetrating light,
and the second cover member 120 can be made of a sheet composed of
a light penetrating material, a non-light penetrating material, or
a reflective material. For example, the first cover member 110 can
be composed of a glass substrate or the like, and the second cover
member 120 can have a TPT (Tedlar/PET/Tedlar) type, or include a
polyvinylidene fluoride (PVDF) resin layer formed on at least one
surface of a base film (for example, polyethylene terephthalate
(PET)).
[0039] However, the present disclosure is not limited thereto.
Accordingly, the first and second sealing members 131 and 132, the
first cover member 110, or the second cover member 120 can include
various materials other than those described above, and can have
various shapes. For example, the first cover member 110 or the
second cover member 120 can have various shapes (for example, a
substrate, a film, a sheet, etc.) or materials.
[0040] Hereinafter, with reference to FIGS. 3 and 4, the
configuration of a solar cell module and a solar cell according to
an embodiment of the present disclosure will be described in more
detail. FIG. 3 is a perspective view illustrating an example of a
solar cell module constituting the solar panel 100 shown in FIG. 1,
and FIG. 4 is a cross-sectional view taken along a line Iv-Iv in
FIG. 3. For simplicity, electrodes 42 and 44 are schematically
illustrated in FIG. 4.
[0041] Referring to FIGS. 3 and 4, the solar cell 150 includes a
semiconductor substrate 160, conductivity type regions 20 and 30
formed at or on the semiconductor substrate 160, and electrodes 42
and 44 connected to the conductivity type regions 20 and 30. The
conductivity type regions 20 and 30 can include a first
conductivity type region 20 having a first conductivity type and a
second conductivity type region 30 having a second conductivity
type. The electrodes 42 and 44 can include a first electrode 42
connected to the first conductivity type region 20 and a second
electrode 44 connected to the second conductivity type region 30.
Furthermore, the solar cell 150 can further include first and
second passivation layers 22 and 32, an anti-reflection layer 24,
and the like.
[0042] The semiconductor substrate 160 can be composed of a
crystalline semiconductor (for example, a single crystal or
polycrystalline semiconductor, for example, a single crystal or
polycrystalline silicon) including a single semiconductor material
(for example, a group 4 element). Then, since the semiconductor
substrate 160 having a high degree of crystallinity and having a
few defects is used as a base, the solar cell 150 can have
excellent electrical characteristics.
[0043] The front surface and/or the back surface of the
semiconductor substrate 160 can be textured to have unevenness. The
unevenness can have, for example, a pyramid shape having an
irregular size, whose outer surface is composed of the plane (111)
of the semiconductor substrate 160. As a result, the reflectance of
light can be reduced if having a relatively large surface
roughness. However, the present disclosure is not limited
thereto.
[0044] In this embodiment, the semiconductor substrate 160 includes
a base region 10 having the first or second conductivity type by
doping a first or second conductivity type dopant with a doping
concentration lower than the first or second conductivity type
region 20, 30. As an example, the base region 10 can have the
second conductivity type in this embodiment.
[0045] As an example, the first conductivity type region 20 can
forms an emitter region that forms a p-n junction with the base
region 10. The second conductivity type region 30 can form a back
surface field to form a back field region for preventing
recombination. Here, the first and second conductivity type regions
20 and 30 can be formed as a whole on the front surface and the
back surface of the semiconductor substrate 160. Thus, the first
and second conductivity type regions 20 and 30 can be formed with a
sufficient area without additional patterning. However, the present
disclosure is not limited thereto.
[0046] In this embodiment, the base region 10 and the conductivity
type regions 20 and 30 being included in the semiconductor
substrate 160 are exemplified as regions having a crystal structure
of the semiconductor substrate 160 and different conductivity type,
doping concentration, etc. That is, it is illustrated that the
conductivity type regions 20 and 30 are doped regions constituting
a part of the semiconductor substrate 160. However, the present
disclosure is not limited thereto. Therefore, at least one of the
first conductivity type region 20 and the second conductivity type
region 30 can be formed of an amorphous, microcrystalline or
polycrystalline semiconductor layer or the like, which is formed on
the semiconductor substrate 160 as a separate layer. Other
variations are possible.
[0047] The first conductivity type dopant included in the first
conductivity type region 20 can be an n-type or p-type dopant, and
the second conductivity type dopant included in the base region 10
and the second conductivity type region 30 can be a p-type or
n-type dopant. Group 3 elements such as boron (B), aluminum (Al),
gallium (Ga), or indium (In) can be used as the p-type dopant, and
group 5 elements such as phosphorus (P), arsenic (As), bismuth
(Bi), and antimony (Sb) can be used as the n-type dopant. The
second conductivity type dopant in the base region 10 and the
second conductivity type dopant in the second conductivity type
region 30 can be the same material or different materials.
[0048] For example, the first conductivity type region 20 can have
a p-type, the base region 10 and the second conductivity type
region 30 can have an n-type. Then, holes having a slower moving
speed than electrons can move to the front surface of the
semiconductor substrate 160, rather than the back surface thereof,
thereby improving the conversion efficiency. However, the present
disclosure is not limited thereto, and the opposite case is also
possible.
[0049] An insulating layer such as the first and second passivation
layers 22 and 32 for immobilizing defects of the conductivity type
regions 20 and 30, and the anti-reflection layer 24 for preventing
reflection of light can be formed on the surface of the
semiconductor substrate 160. Such an insulating layer can be
composed of an undoped insulating layer which does not contain a
dopant separately. The first and second passivation layers 22 and
32 and the anti-reflection layer 24 can be formed substantially
entirely on the front surface and back surface of the semiconductor
substrate 160 except for parts (more precisely, parts where a first
or second opening is formed) corresponding to the first or second
electrode 42, 44.
[0050] For example, the first or second passivation layer 22, 32 or
the anti-reflection layer 24 can have a silicon nitride layer, a
silicon nitride layer containing hydrogen, a silicon oxide layer, a
silicon oxynitride layer, an aluminum oxide layer, any one single
layer selected from a group consisting of MgF.sub.2, ZnS, TiO.sub.2
and CeO.sub.2 or a multi-layered structure in which two or more
layers are combined. For example, the first or second passivation
layer 22 or 32 can include a silicon oxide layer, a silicon nitride
layer, or the like having a fixed positive charge when the first or
second conductivity type region 20 or 30 has an n-type, and can
include an aluminum oxide layer, or the like having a fixed
negative charge when the first or second conductivity type region
20 or 30 has a p-type. As one example, the anti-reflection layer 24
can include silicon nitride. In addition, the material of the
insulating layer, the multi-layered structure, and the like can be
variously modified.
[0051] The first electrode 42 is electrically connected to the
first conductivity type region 20 through a first opening and the
second electrode 44 is electrically connected to the second
conductivity type region 30 through a second opening. The first and
second electrodes 42 and 44 are made of various materials (for
example, metal materials) and can be formed to have various shapes.
The shape of the first and second electrodes 42 and 44 will be
described later.
[0052] As described above, in this embodiment, since the first and
second electrodes 42 and 44 of the solar cell 150 have a certain
pattern, the solar cell 150 has a bi-facial structure in which
light can be incident on the front surface and the back surface of
the semiconductor substrate 160. Accordingly, the amount of light
used in the solar cell 150 can be increased to contribute to the
efficiency improvement of the solar cell 150.
[0053] However, the present disclosure is not limited thereto, and
it is also possible that the second electrode 44 is formed entirely
on the back surface of the semiconductor substrate 160. It is also
possible that the first and second conductivity type regions 20 and
30 and the first and second electrodes 42 and 44 are positioned
together on one surface (for example, the back surface) of the
semiconductor substrate 160, and it is also possible that at least
one of the first and second conductivity type regions 20 and 30 is
formed over both surface of the semiconductor substrate 160. That
is, the solar cell 150 described above is merely an example, and
the present disclosure is not limited thereto.
[0054] The solar cell 150 described above is electrically connected
to the neighboring solar cell 150 by the wiring member 142
positioned (e.g., in contact with) on the first electrode 42 or the
second electrode 44.
[0055] The solar cell 150 having such a configuration is fabricated
by dividing a mother solar cell into two or more pieces, such as
half, and when first and second solar cells 151 and 152 are
combined, it can be a single mother solar cell. Such a mother solar
cell will be described in detail later with reference to FIG.
6.
[0056] In an embodiment of the present disclosure, the solar cell
module includes the plurality of solar cells and the plurality of
wiring members for electrically connecting neighboring two solar
cells. In FIG. 3, only two first and second solar cells 151 and 152
are selectively shown for simplicity of illustration. In addition,
in FIG. 3, the first and second solar cells 151 and 152 are
schematically illustrated mainly on the semiconductor substrate 160
and the electrodes 42 and 44.
[0057] Regarding the wiring member, it will be described in detail
with reference to FIGS. 4 and 5. FIG. 5 is a perspective view
showing an overall appearance of a wiring member.
[0058] Referring to FIGS. 4 and 5, the wiring member 142 connects
the second electrode 44 positioned on a back surface of the first
solar cell 151 and the first electrode 42 positioned on a front
surface of the second solar cell 152 disposed to be adjacent to the
right side of the first solar cell 151. Another wiring member 142
connects the first electrode 42 positioned on a front surface of
the first solar cell 151 and the second electrode 44 positioned on
a back surface of another solar cell disposed to be adjacent to the
left side of the first solar cell 151. Other wiring member 142
connects the second electrode 44 positioned on a back surface of
the second solar cell 152 and the first electrode 42 positioned on
a front surface of other solar cell disposed to be adjacent to the
right side of the second solar cell 152. Accordingly, the plurality
of solar cells 150 can be connected to each other by the wiring
member 142 to form one row. Hereinafter, the description of the
wiring member 142 can be applied to all the wiring member 142
connecting two neighboring solar cells 150.
[0059] As such, the wiring member electrically and physically
connects the first electrode 42 disposed on the front surface of
the neighboring first solar cell 151 and the second electrode 44
disposed on the back surface of the second solar cell 152. Thus,
the wiring member 142 is bent in a form of a diagonal line between
the first solar cell 151 and the second solar cell 152 so that a
part of the wiring member 142 is connected to the first electrode
42 disposed on the front surface of the first solar cell 151, and
the other part is connected to the second electrodes 44 disposed on
the back surface of the second solar cell 152, respectively, to
electrically connect two neighboring solar cells.
[0060] However, at this time, if the number of wiring members for
connecting the two neighboring solar cells is too large, or the
thickness of the wiring members becomes thick, it is difficult to
bend them, so that a distance between the first and second solar
cells is inevitably increased. As a result, the overall size of the
solar panel increases.
[0061] Furthermore, when the solar cell module is configured with
the divided solar cells as in the present disclosure, since the
number of solar cells forming a string increases in multiples than
that of the mother solar cell, the size of the solar panel is bound
to be larger.
[0062] In view of this, it is preferable that the wiring member 142
is configured to have a thin diameter wire shape so as to bend
well. Since the wiring member 142 has a wire shape unlike a ribbon
having a relatively wide width (for example, 1 mm to 2 mm), which
is used in the past, and also, the thickness is very thin than that
of the ribbon, the amount of light incident on the solar cell can
be increased more effectively. In addition, since it bends more
easily than the conventional ribbon, in one embodiment, it is
possible to prevent the overall size of the solar cell panel from
growing by effectively reducing the distance between the solar
cells formed of the divided solar cells.
[0063] As an example, the maximum width of the wiring member 142 is
250 .mu.m to 500 .mu.m or approximately thereabout, for example 270
.mu.m to 320 .mu.m or approximately thereabout. In addition, the
maximum width of the wiring member can be adjusted by using the
number of wiring members as a variable, for example, when the
number of wiring members becomes large, the diameter of the wiring
member becomes smaller as the number increases in order to
effectively maintain the distance between the first and second
solar cells, and when the number of wiring member becomes small,
the diameter of the wiring member can be larger. This is described
in detail below.
[0064] The number of the wiring members 142 can be greater than the
number (for example, 2 to 5) of the conventional ribbons on the
basis of one surface of each solar cell 150. Then, a movement
distance of carriers can be reduced by a large number of the wiring
members 142 while minimizing the optical loss and material cost by
the wiring member 142 having a small width. Thus, the efficiency of
the solar cell 150 and the output of the solar cell panel 100 can
be improved by reducing the movement distance of the carriers while
reducing the optical loss, and productivity of the solar cell panel
100 can be improved by reducing the material cost due to the wiring
member 142.
[0065] In order to prevent the process of attaching the wiring
member 142 to the solar cell 150 from becoming complicated when the
number of the wiring member 142 having the small width is used in a
large number, in this embodiment, the wiring member 142 can have a
structure including a core layer 142a and a solder layer 142b
formed on the surface of the core layer 142a as shown in (A) of
FIG. 5. Then, a large number of the wiring member 142 can be
effectively attached by the process of applying heat and pressure
while the wiring member 142 is placed on the solar cell 150.
[0066] The wiring member 142 or the core layer 142a, which is
included in the wiring member 142 and occupies most of the wiring
member 142, can include rounded parts. That is, at least a part of
the cross section of the wiring member 142 or the core layer 142a
can include a circle, a part of a circle, an ellipse, a part of an
ellipse, or a part made of a curved line. In addition, the wiring
member 142 can have a polygonal shape having at least three
vertices, that is, a cross-section of the wiring member can have a
figure shape surrounded by three or more line segments, and in this
case, the light incident toward the wiring member can cause
diffused reflection on the surface of the wiring member, thereby
increasing the amount of light incident on the solar cell more
effectively.
[0067] If it has such a shape, the wiring member 142 is formed in a
structure in which the solder layer 142b is entirely positioned on
the surface of the core layer 142a, the process of separately
applying the solder material and the like are omitted, so that the
wiring member 142 can be attached by positioning the wiring member
142 directly on the solar cell 150.
[0068] Thus, the process of attaching the wiring member 142 can be
simplified. In addition, a light incident on the solar cell can be
reflected or diffused by a rounded portion of the wiring member 142
so that the light reflected from the wiring member 142 can be
re-entered into the solar cell 150. Accordingly, since the amount
of light incident on the solar cell 150 is increased, the
efficiency of the solar cell 150 and the output of the solar cell
panel 100 can be improved.
[0069] In addition, as the wiring member has a wire shape, the
wiring member can be stretched or bent well, thereby effectively
reducing the distance between the first and second solar cells, and
as a result, even when the solar cell panel is composed of the
divided solar cells, the total size of the solar cell panel is not
increased, and thus the solar cell panel can be produced even with
the divided solar cells using the existing equipment that is, the
manufacturing equipment installed to manufacture the solar cells
using the mother solar cell.
[0070] The wiring members 142 can be disposed by about 6 to 24
based on one surface of the solar cell 150, for example by about 8
to 12. The wiring members can be positioned on the solar cell 150
at a uniform distance from each other.
[0071] In this embodiment, the wiring member 142 can include the
core layer 142a made of metals and the solder layer 142b that is
formed on the surface of the core layer 142a and includes solder
material to enable soldering with the electrodes 42,44. That is,
the solder layer 142b can serve as a kind of adhesive layer. For
example, the core layer 142a can include Ni, Cu, Ag, Al, or the
like as a main material (for example, a material containing 50 wt %
or more, more specifically, a material containing 90 wt % or more).
The solder layer 142b can include a solder material such as Pb, Sn,
SnIn, SnBi, SnPb, SnPbAg, SnCuAg, SnCu, or the like as a main
material. However, the present disclosure is not limited thereto,
and the core layer 142a and the solder layer 142b can include
various materials.
[0072] As shown in (B) of FIG. 5, a total thickness of the wiring
member 142 composed as described above, that is, the total
thickness (D2+D1+D2) including the core layer 142a and the solder
layer 142b, is 270 .mu.m to 320 .mu.m or approximately thereabout,
and it is preferable that the thickness D1 of the core layer 142a
among this is 240 to 280 .mu.m or approximately thereabout, for
example, 255 to 265 .mu.m or approximately thereabout. Here, the
thickness of the core layer 142a refers to an average value of the
thicknesses measured based on the cross section.
[0073] If the thickness D1 of the core layer 142a is smaller than
240 .mu.m or approximately thereabout, the line resistance becomes
too large and the output efficiency decreases excessively, and if
it is thicker than 280 .mu.m or approximately thereabout, it is
impossible to bend the wiring member 142 into a desired shape due
to the core layer made of metal, and thus it is impossible to
reduce the size between the first and second solar cells to a
desired size.
[0074] In addition, the solder layer 142b for example has a
thickness D2 of at least 15 .mu.m or more or approximately
thereabout so that the wiring member 142 can be bonded to the
electrode (or a pad in the case of having the pad) with a desired
bonding force in the tabbing process. Here, the thickness D2 refers
to the thickness of one cross-section of the solder layer 142b
surrounding the core layer 142a, and the total thickness of the
solder layer 142b is a value obtained by adding both cross-sections
together. During the tabbing process, the solder layer 142b is
melted and solidified at the melting temperature, thereby bonding
the wiring member to the electrode (or the pad in the case of
having the pad). However, if the thickness D2 of the solder layer
142b is less than 15 .mu.m or approximately thereabout, the amount
of solder applied to the pad or the electrode can be small and
cannot have a sufficient bonding strength desired. Furthermore,
when the wiring member 142 is bonded to the pad, the whole pad
needs to be applied by the solder, however, if the thickness D2 of
the solder layer is less than 15 .mu.m or approximately thereabout,
the whole pad cannot be applied with the solder, and thus the
desired bonding strength cannot be obtained.
[0075] In addition, the thickness D2 of the solder layer 142b is
for example less than 20 .mu.m or approximately thereabout. If the
thickness D2 of the solder layer 142b is greater than 20 .mu.m or
approximately thereabout, the curvature of the wiring member is
sharply dropped, and it is virtually impossible to maintain the
distance between two neighboring solar cells at 0.5 to 1.5 mm.
[0076] Considering this point, in order to maintain the distance
between the two solar cells at 0.5 to 1.5 mm, it is preferable that
the thickness D1 of the core layer 142a and the thickness D2 of the
solder layer 142b are 0.05<D2/D1<0.08. Here, the thickness D2
of the solder layer 142b refers to the thickness of only one
surface or section of the solder layer 142b. In embodiments of the
invention, the thickness D2 of the solder layer 142b can be 5% to
8% of the thickness D1 of the core layer 142a or approximately
thereabout to maintain the distance between the two solar cells 151
and 152 at 0.5 to 1.5 mm or approximately thereabout.
[0077] On the other hand, when the wiring member 142 is attached to
the solar cell 150 by a tabbing process, as shown in FIG. 4, a
shape of the solder layer 142b is changed in a part of the wiring
member 142 attached to or connected to the solar cell 150.
[0078] More specifically, the wiring member 142 is attached to the
electrodes 42 and 44 (the pad when the pad is provided) by the
solder layer 142b. At this time, the solder layer 142b of each
wiring member 142 is positioned on the electrodes 42 and 44
separately from the other wiring member 142. When the wiring member
142 is attached to the solar cell 150 by the tabbing process, each
solder layer 142b flows down to the first or second electrodes 42,
44 (more specifically, the pad parts 422 and 424) as a whole during
the tabbing process, and a width of the solder layer 142b can
gradually increase toward the pad parts 422, 442 at a part adjacent
to each pad part 422, 442 or a part positioned between the pad
parts 422, 442 and the core layer 142a. As one example, the part
adjacent to the pad parts 422 and 442 in the solder layer 142b can
have a width equal to or greater than a diameter of the core layer
142a. At this time, the width of the solder layer 142b can be equal
to or less than a width of the pad parts 422, 442. In the
embodiment of FIG. 6, also shown are an inner pad part 421 and an
outer pad part 424a.
[0079] More specifically, the solder layer 142b has a shape
protruding toward the outside of the solar cell 150 along the shape
of the core layer 142a in an upper part of the core layer 142a. On
the other hand, the solder layer 142b includes a part having a
concave shape with respect to the outside of the solar cell 150 in
a lower part of the core layer 142a or a part adjacent to the pad
parts 422 and 442. As a result, an inflection point where the
curvature changes is positioned on the side surface of the solder
layer 142b. It can be seen that the wiring member 142 are
individually attached and fixed by the solder layer 142b without
being inserted or covered in a separate layer, film, or the like
from this shape of the solder layer 142b. The solar cell 150 and
the wiring member 142 can be connected by a simple structure and a
process by fixing the wiring member 142 by the solder layer 142b
without using a separate layer or a film. Particularly, the wiring
member 142 having a narrow width and a rounded shape as in the
present embodiment can be attached without using a separate layer,
a film, (for example, a conductive adhesive film including a resin
and a conductive material) or the like, so that the process cost
and time of the wiring member 142 can be minimized.
[0080] On the other hand, the part of the wiring member 142
positioned between the neighboring solar cells 150 (that is,
outside the solar cell 150), which is not applied with heat or is
applied with relatively less heat even after the tabbing process,
can have a shape in which the solder layer 142b has a uniform
thickness as shown in FIG. 4.
[0081] According to the present embodiment, optical loss can be
minimized by diffused reflection or the like using a wire-shaped
wiring material 142, and it is possible to reduce the movement path
of the carrier by increasing the number of the wiring member 142
and reducing a pitch of the wiring member 142. In addition, the
width or diameter of the wiring member 142 can be reduced, so that
the material cost can be greatly reduced. Accordingly, the
efficiency of the solar cell 150 and the output of the solar cell
panel 100 can be improved.
[0082] The solar cell module of an embodiment having such a
configuration is made through the solar cell made by dividing the
mother solar cell into a plurality. FIG. 6 is a plan view
illustrating a front surface of an example mother solar cell.
Hereinafter, referring to FIGS. 3 and 6, an embodiment of a solar
cell module will be described.
[0083] In the present embodiment, one mother solar cell 150a is cut
along a cutting line CL to manufacture first and second solar cells
151 and 152 which are a plurality of solar cells. Each of the first
and second solar cells 151 and 152, which are unit solar cells,
functions as one solar cell 150. When the mother solar cell 150a is
divided into two solar cells 150 as described above, cell to module
loss (CTM loss), which occurs when the plurality of solar cells 150
are connected to form the solar panel 100, can be reduced. That is,
if the area of the solar cell is reduced to reduce the current
generated by the solar cell itself, the CTM loss of the solar panel
100 can be reduced by reducing the current reflected by the squared
value even if the number of the solar cells 150 reflected as it is
increased.
[0084] In this embodiment, after manufacturing the mother solar
cell 150a according to a prior manufacturing method, the mother
cell can be cut to reduce the area of the solar cell 150. According
to this, since the equipment is used as it is, the mother solar
cell 150a can be cut after using the optimized production
conditions as it is. This minimizes the burden on equipment and
process costs. On the other hand, reducing the size of the mother
solar cell (150a) itself, there is a burden such as replacing the
used equipment or reset the production conditions.
[0085] In general, the semiconductor substrate 160 of the mother
solar cell 150a is manufactured from an ingot of approximately
circular shape, and lengths of sides in two axes (for example, an
axis parallel to a finger line 42a and an axis parallel to a bus
bar 42b) orthogonal to each other, such as circular, square or
similar shapes, are the same or almost similar to each other. For
example, in the present embodiment, the semiconductor substrate 160
of the mother solar cell 150a can have an octagonal shape having
inclined sides 160a at four corners thereof in an approximately
square shape. With such a shape, the semiconductor substrate 160
having the largest area can be obtained from the same ingot.
Accordingly, the mother solar cell 150a has a symmetrical shape,
and a maximum horizontal axis and a maximum vertical axis, and a
minimum horizontal axis and a minimum vertical axis have the same
distance.
[0086] In this embodiment, since the mother solar cell 150a is cut
along the cutting line CL to form the solar cell 150, the
semiconductor substrate 160 of the solar cell 150 has a shape
having a long axis and a short axis. In the present embodiment, the
cutting line CL is parallel to the first direction (y-axis
direction in the drawing) in the longitudinal direction of the
first and second conductivity-type regions 20 and 30 and the finger
lines 42a (or first finger lines 42a) and 44a (or second finger
lines 44a). It can be continued to intersect the second direction
(the x-axis direction in the drawing) which is the extending
direction of the bars 42b (or first bus bars 42b) and 44b (or
second bus bars 44b). Therefore, the plurality of solar cells 150
can be formed long in the first direction.
[0087] Accordingly, in the first electrode 42 positioned on the
front surface of the semiconductor substrate 160 in each solar cell
150, a plurality of first finger lines 42a extend in the first
direction parallel to the long axis and are positioned in parallel
with each other, and a first bus bar 42b is formed in the second
direction parallel to the short axis. The first bus bar 42b can
include a plurality of first pad parts 422 spaced apart from each
other in the second direction parallel to the short axis.
Similarly, in the second electrode 44, a plurality of second finger
lines extend in the first direction parallel to the long axis and
are positioned in parallel with each other, and a second bus bar is
formed in the second direction parallel to the short axis. The
second bus bar can include a plurality of second pad parts.
Descriptions of the shape, position, and the like of the first
finger line 42a and the first bus bar 42b can be applied to the
second finger line and the second bus bar as it is. The first
electrode 42 also includes connection lines 42c at the inclined
sides 160a that connect some of the plurality of first finger lines
42a along a periphery of the first and second solar cells 151 and
152.
[0088] Accordingly, the long axis of the solar cell 150 is
positioned in parallel with the first direction, the short axis of
the solar cell 150 is positioned in parallel with the second
direction, and the wiring member 142 connects the neighboring first
and second solar cells 151 and 152 in the short axis direction (see
FIG. 3).
[0089] In FIG. 3, after cutting one mother solar cell 150 into two,
an inclined side 160a is disposed to be positioned in the same
direction, so that it is illustrated that the cut surfaces along
the cutting line CL are not in contact with each other. As a
result, when the cut surfaces formed by the cutting lines CL are
not disposed to face each other, the risk of electrical shorting
and the like can be reduced as compared to face each other,
however, the present disclosure is not limited thereto, and the cut
surfaces can be disposed to face each other.
[0090] In the above-described drawings and descriptions, it was
illustrated that one mother solar cell 150a was cut along one
cutting line CL to form two solar cells 150. However, the present
disclosure is not limited thereto, and it is also possible to form
three or more solar cells 150 by cutting one mother solar cell 150a
along two or more cutting lines CL.
[0091] In addition, in the above-described drawing and description,
the first electrode 42 and/or the second electrode 44 are not
formed near the cutting line CL, so that the first electrode 42
corresponding to each solar cell 150 and/or the second electrode 44
is positioned apart from each other with the cutting line CL
interposed therebetween. However, the present disclosure is not
limited thereto, and the first electrode 42 and/or the second
electrode 44 corresponding to the plurality of solar cells 150 can
be formed to be connected to each other and separated from each
other by the cutting line CL in the mother solar cell 150a. For
example, after the mother solar cell 150a having the bus bar and
the pad part is formed, the solar cell 150 can be formed by cutting
the mother solar cell 150a along the cutting line CL parallel to
the first direction.
[0092] The structures of the first and second electrodes 42 and 44
described above can be applied to the plurality of solar cells 150,
respectively, or can be applied to any one or some of the plurality
of solar cells 150.
[0093] FIG. 7 is a plan view illustrating a schematic view of a
solar cell module shown in FIG. 3. FIG. 8 is a cross-sectional view
taken along a line VIII-VIII in FIG. 7. FIG. 7 and FIG. 8 are shown
in a simplified form for convenience of description.
[0094] In the solar cell module according to an embodiment, the
first and second solar cells 151 and 152 are disposed to face each
other with neighboring side surfaces, and also spaced apart from
each other to have a first distance G. In FIG. 7, only neighboring
first and second solar cells 151 and 152 are illustrated, but two
neighboring solar cells in one entire string can be disposed to
have such a first distance G.
[0095] The plurality of wiring members 142 are disposed to connect
the neighboring first and second solar cells 151 and 152 and can be
separated from each other by distances D1-D10, each of which can be
a constant interval or a varying interval, one side of the wiring
member is joined to the first electrode 42 disposed on the front
surface of the first solar cell 151, and the other side is joined
to the second electrode 44 disposed on the back surface of the
second solar cell 152. Therefore, the wiring member 142 is bent
between the first and second solar cells 151 and 152. More
precisely, the wiring member 142 is bent to ride down the side of
the first solar cell 151 between the first and second solar cells
151 and 152. In addition, the wiring member 142 is close to the
side of the second solar cell 152 and is oriented upwardly with
respect to the side, or at least bent in parallel with the second
electrode 44 of the second solar cell 152. As described above, the
wiring member 142 has an inflection point at which the bending
direction is changed at points adjacent to the side of the first
solar cell 151 and the side of the second solar cell 152.
[0096] Therefore, the amount of bending of the wiring member 142 is
determined according to this inflection point, and the first
distance G, which is a degree of spreading of the first and second
solar cells, is determined according to the bending of the wiring
member 142. The first distance G can be changed based on the
thickness of the wiring member 142.
[0097] In one example, the second solar cell 152 can be disposed to
be adjacent to the first solar cell 151 by rotating 180 degrees to
have the same shape as the first solar cell. Here, the first solar
cell 151 and the second solar cell 152 are solar cells formed by
cutting one mother solar cell 150 along the cutting line CL.
Accordingly, both the first and second solar cells 151 and 152 can
be disposed so that chamfers face to the right side, and cut
surfaces (surfaces which cut the mother solar cell) face to the
left side.
[0098] In this arrangement, as well as improve the appearance of
the solar cell module, there is an effect to further reduce the
distance G between the first and second solar cells 151 and 152. In
one example, when one mother solar cell 150 is cut with a laser
along the cutting line CL, the surface of the solar cell to which
the laser is irradiated generates burrs due to the high heat of the
laser and the generated burrs are fused around the cut surface. In
one example, the solar cell 150 can divide the first and second
solar cells into two by irradiating a laser on the back surface,
thereby preventing the pn junction from being damaged by
irradiating the laser on the back surface rather than the front
surface where the light is incident. Thus, in this case, the burrs
can be fused on the back surface of the solar cell.
[0099] If the first and second solar cells 151 and 152 are disposed
to face the cut surfaces, and the first and second solar cells 151
and 152 are connected by the wiring member 142, since the wiring
member 142 should be bent in an oblique direction between the first
and second solar cells 151 and 152, the burrs fused to the cut
surfaces in a protrusion shape can be electrically shorted with the
wiring member. Therefore, when the first and second solar cells 151
and 152 are disposed and connected to face the cut surfaces
differently from the arrangement shown in FIG. 7, there can be a
limit in reducing the distance G between the first solar cell 151
and the second solar cell 152, for example, at least 2.5 mm should
have a distance.
[0100] However, according to the arrangement as shown in FIG. 7,
the first solar cell 151 is disposed so that the cut surface of the
first solar cell 151 faces the second solar cell, but the second
solar cell 152 is disposed so that the non-cut surface of the
second solar cell 152 faces the cut surface of the first solar cell
151. Since a part of the wiring member 142 is disposed on the back
surface of the second solar cell 152, and the other part is
positioned on the front surface of the first solar cell 151, the
wiring member is bent in an oblique direction upward between the
first solar cell 151 and the second solar cell 152. In this case,
since the first solar cell 151 has the non-cut surface and the
second solar cell 152 has the cut surface, but the wiring member
142 is disposed on the front surface, two neighboring solar cells
151 and 152 can be electrically connected to each other to avoid
interference of burrs formed on the back surface of the cut
surface. Therefore, the distance G between the first and second
solar cells 151 and 152 can be less than before, for example, 2.5
mm, for example, depending on the thickness, number, etc. of wiring
members, the distance G can be determined in a range of 0.5 mm to
1.5 mm.
[0101] FIGS. 9 and 10 are graphs showing output and efficiency of a
module depending on a thickness of a wiring member. In FIG. 9 and
FIG. 10, experimental examples (half wire thks 360.about.half wire
thks 180) compose a solar cell module using unit solar cells formed
by dividing a mother solar cell into two, and comparative examples
(full wire thks 320.about.half wire thks 240) compose a solar cell
module using a mother solar cell. In the experimental examples,
unit solar cells 6*20 are connected in series, and in the
comparative examples, mother solar cells 6*10 are connected in
series. In FIG. 9, the solar cells of the experimental examples and
the mother solar cells of the comparative examples are disposed 2.5
mm apart from neighboring strings in each string, in FIG. 10, being
disposed 1.0 (mm) apart, so that it can be seen not only the output
comparison between the comparative example and the experimental
example, but also how the output varies depending on the
disposition distance G of the solar cell. In FIG. 9 and FIG. 10,
the thickness of the wiring member means the thickness of the core
layer.
[0102] First, in FIG. 9, it can be seen that the module output of
the experiment examples (half wire thks 360.about.half wire thks
180) is greater than that of the comparative examples (full wire
thks 320.about.half wire thks 240). Here, the module output (P) is
a value obtained by Equation 1 below, and means a value obtained by
multiplying a voltage (V) and a current (I) produced by the solar
cell module. In embodiments of the invention, thks refers to
thickness
P=VI (W) [Equation 1]
[0103] As can be seen through FIGS. 9 and 10, it can be seen that
the experimental examples have a larger module output than the
comparative examples regardless of the thickness of the wiring
member, and it can be seen that the thicker the wiring member, the
more the module output increases in both the experimental examples
and the comparative examples.
[0104] In comparison, in the case of the comparative examples, the
module output increases as the number of wiring members increases,
but it can be seen that at some point, that is, the number of
wiring members converges to a constant value from 12, and this
phenomenon can be similarly confirmed in the experimental examples.
When the number of wiring members is larger than 12, it can be seen
that the module output is not greatly improved in consideration of
the error range. In addition, since the output is reduced by about
twice at a point where the number of wiring members is 8 or less
(between 6 and 8) than at a point where the number of wiring
members is 8 or more (between 8 and 10) based on a point where the
number of wiring members is 8, it can be seen that this point (the
number of wiring members is 8) is an inflection point.
[0105] Considering these, the number of wiring members in the
present disclosure is for example 8 or more, 12 or less, but the
present disclosure is not limited thereto, and the number of wiring
members can be 6 to 24 in consideration of various variable
conditions in manufacturing.
[0106] In addition, when the thickness of the wiring member is 255
to 265 .mu.m or approximately thereabout (half wire thks 260 in the
drawing), it can be acknowledged that the module output that is
evenly distributed regardless of the number of wiring members
compared to other experimental examples. Therefore, when the
thickness of the wiring member, more precisely, the thickness D1 of
the core layer is composed of 255 to 265 .mu.m or approximately
thereabout, it is possible to manufacture a solar cell module with
no deviation within the error range.
[0107] Hereinafter, look at the module output change of the
experimental examples. The experimental examples of FIG. 9 show the
module output when the disposition distance of the unit solar cells
is 2.5 (mm), and the experimental examples of FIG. 10 show the
module output when the disposition distance of the unit solar cells
is 1.0 (mm). Comparing FIG. 9 and FIG. 10, it can be seen that the
module output of the experimental examples of FIG. 10 is reduced by
about 2.4 (W) as a whole than the module output of the experimental
examples of FIG. 9. This reduction in power means a reduction in
power of less than about 1%, based on module output 350 (W).
[0108] On the other hand, it can be seen that the experimental
examples of FIG. 10 is higher than the experimental examples of
FIG. 9 in the module efficiency. Here, the module output (P) refers
to absolute output produced by the module, and the module
efficiency (Q) refers to relative output produced per unit area
(S). The module efficiency is defined as in Equation 2 below.
Q=P/S (W/mm.sup.2) [Equation 2]
[0109] When a module is composed with a disposition distance of 2.5
(mm) in the unit solar cell, an area of the module is 1,740
(mm)*1,016 (mm)=1,767,840 (mm.sup.2), and when a module is composed
with a disposition distance of 1.0 (mm) in the unit solar cell, an
area of the module is 1,686*1,016 (mm)=1,712,976 (mm.sup.2).
[0110] Therefore, it can be seen that the module efficiency of the
experimental examples of FIG. 10 is about 2 to 3% higher than the
module efficiency of the experimental examples of FIG. 9. As
described above, when comparing the experimental example and the
comparative example, when the solar cell disposition distance is
reduced, the module output can slightly decrease, but the module
efficiency increases by more than the decrease of the module
output, so that overall module efficiency can be increased.
[0111] Although embodiments have been described with reference to a
number of illustrative embodiments thereof, it should be understood
that numerous other modifications and embodiments can be devised by
those skilled in the art that will fall within the scope of the
principles of this disclosure. More particularly, various
variations and modifications are possible in the component parts
and/or arrangements of the subject combination arrangement within
the scope of the disclosure, the drawings and the appended claims.
In addition to variations and modifications in the component parts
and/or arrangements, alternative uses will also be apparent to
those skilled in the art.
* * * * *