U.S. patent application number 17/724439 was filed with the patent office on 2022-09-08 for semiconductor chip package and method of forming.
The applicant listed for this patent is JINKO SOLAR CO., LTD., ZHEJIANG JINKO SOLAR CO., LTD.. Invention is credited to Zhiqiu Guo, Guohui Hao, Shiliang Huang, Jiaming Zhu.
Application Number | 20220285572 17/724439 |
Document ID | / |
Family ID | 1000006274824 |
Filed Date | 2022-09-08 |
United States Patent
Application |
20220285572 |
Kind Code |
A1 |
Huang; Shiliang ; et
al. |
September 8, 2022 |
SEMICONDUCTOR CHIP PACKAGE AND METHOD OF FORMING
Abstract
A solar cell string and a photovoltaic module are provided. The
solar cell string includes a first adhesive layer including N
placement regions sequentially arranged along a first direction, N
solar cells, first wires, and a second adhesive layer. Each of the
N solar cells is disposed on a corresponding placement region of
the N placement regions. The first wires stretch across adjacent
placement regions to electrically connect adjacent solar cells. The
second adhesive layer is disposed on the surface of the at least
one of the N solar cells away from the first adhesive layer, the
first wires are located between the second adhesive layer and the
at least one of the N solar cells, and the first adhesive layer,
the first wires, the N solar cells, and the second adhesive layer
are bonded and fixed.
Inventors: |
Huang; Shiliang; (Haining,
CN) ; Guo; Zhiqiu; (Haining, CN) ; Zhu;
Jiaming; (Haining, CN) ; Hao; Guohui;
(Haining, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ZHEJIANG JINKO SOLAR CO., LTD.
JINKO SOLAR CO., LTD. |
Haining
Jiangxi |
|
CN
CN |
|
|
Family ID: |
1000006274824 |
Appl. No.: |
17/724439 |
Filed: |
April 19, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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17322885 |
May 17, 2021 |
11362226 |
|
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17724439 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 31/0512 20130101;
H01L 31/0481 20130101; H01L 31/0504 20130101 |
International
Class: |
H01L 31/05 20060101
H01L031/05; H01L 31/048 20060101 H01L031/048 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 5, 2021 |
CN |
202110246919.9 |
Claims
1. A solar cell string, comprising: a first adhesive layer, wherein
the first adhesive layer comprises N placement regions sequentially
arranged along a first direction, and the N is a positive integer
greater than 1; N solar cells, wherein each of the N solar cells is
disposed on a corresponding placement region of the N placement
regions; first wires, wherein the first wires are laid on a surface
of at least one of the N solar cells away from the first adhesive
layer, and the first wires stretch across adjacent placement
regions to electrically connect adjacent solar cells; and a second
adhesive layer, wherein the second adhesive layer is disposed on
the surface of the at least one of the N solar cells away from the
first adhesive layer, the first wires are located between the
second adhesive layer and the at least one of the N solar cells,
and the first adhesive layer, the first wires, the N solar cells,
and the second adhesive layer are bonded and fixed.
2. The solar cell string according to claim 1, wherein the N solar
cells comprise a first solar cell at a head portion of the solar
cell string and an Nth solar cell at a tail portion of the solar
cell string respectively; the solar cell string further comprises:
head wires, wherein the head wires are located between the first
adhesive layer and the first solar cell and extend outside the
first solar cell; tail wires, wherein the tail wires are located on
a surface of the Nth solar cell away from the first adhesive layer,
and extend outside the Nth solar cell; and the second adhesive
layer is disposed on the surface of the Nth solar cell away from
the first adhesive layer; and at least two bus bars, wherein one of
the bus bars is contacted and connected with the head wire
extending outside the first solar cell, and the other bus bar is
contacted and connected with the tail wire extending outside the
Nth solar cell; and extend directions of the two bus bars are both
different from the first direction.
3. The solar cell string according to claim 1, wherein in the first
direction, an absolute value of a difference between a total length
of the N solar cells and a length of the first adhesive layer is
less than or equal to 100 mm and an absolute value of a difference
between a length of the second adhesive layer and a total length of
the N solar cells is less than or equal to 60 mm.
4. The solar cell string according to claim 1, wherein the first
adhesive layer comprises a support layer and an adhesive layer, and
the adhesive layer is located between the support layer and the N
solar cells; the second adhesive layer is of a single-layer
structure.
5. The solar cell string according to claim 1, wherein
light-receiving surfaces of the N solar cells face a same
direction, and each of the first wires comprises a light-receiving
wire, a connecting wire, and a rear wire that are sequentially
connected, wherein for each first wire of the first wires, the
light-receiving wire of the first wire is disposed on a
light-receiving surface of a corresponding solar cell of the N
solar cells, and the rear wire of the first wire is located on an
adjacent placement region of the first adhesive layer, wherein the
light-receiving surface is away from the first adhesive layer.
6. The solar cell string according to claim 5, wherein
light-receiving wires on the light-receiving surface of the
corresponding solar cell of the N solar cells are dense grid lines,
the light-receiving surface of the corresponding solar cell of the
N solar cells is provided with subgrid lines arranged at intervals,
and the subgrid lines intersect and contact with the dense grid
lines, wherein the second adhesive layer is disposed on surfaces of
the subgrid lines.
7. The solar cell string according to claim 5, wherein 8 to 32
light-receiving wires are laid at intervals on the light-receiving
surface of each of the N solar cells.
8. The solar cell string according to claim 1, wherein in the first
direction, an absolute value of a difference between a length of
the head wire and a length of the first solar cell is less than or
equal to 20 mm.
9. The solar cell string according to claim 1, wherein in the first
direction, an absolute value of a difference between a length of
any of the first wires and twice a length of any of the solar cells
is less than or equal to 40 mm.
10. The solar cell string according to claim 1, wherein each of the
first wires comprises a solder core and an alloy layer surrounding
the solder core, and the alloy layer is made from at least one
material selected from a group consisting of Sn, Pb, Bi, In, Zn,
Cu, Sb, and Ag.
11. A photovoltaic module, comprising a first substrate, a first
encapsulating layer, a solar cell string, a second encapsulating
layer, and a second substrate are stacked in sequence, wherein the
solar cell string comprises: a first adhesive layer, wherein the
first adhesive layer comprises N placement regions sequentially
arranged along a first direction, and the N is a positive integer
greater than 1; N solar cells, wherein each of the N solar cells is
disposed on a corresponding placement region of the N placement
regions; first wires, wherein the first wires are laid on a surface
of at least one of the N solar cells away from the first adhesive
layer, and the first wires stretch across adjacent placement
regions to electrically connect adjacent solar cells; and a second
adhesive layer, wherein the second adhesive layer is disposed on
the surface of the at least one of the N solar cells away from the
first adhesive layer, the first wires are located between the
second adhesive layer and the at least one of the N solar cells,
and the first adhesive layer, the first wires, the N solar cells,
and the second adhesive layer are bonded and fixed.
12. The photovoltaic module according to claim 11, wherein the N
solar cells comprise a first solar cell at a head portion of the
solar cell string and an Nth solar cell at a tail portion of the
solar cell string respectively; the solar cell string further
comprises: head wires, wherein the head wires are located between
the first adhesive layer and the first solar cell and extend
outside the first solar cell; tail wires, wherein the tail wires
are located on a surface of the Nth solar cell away from the first
adhesive layer, and extend outside the Nth solar cell; and the
second adhesive layer is disposed on the surface of the Nth solar
cell away from the first adhesive layer; and at least two bus bars,
wherein one of the bus bars is contacted and connected with the
head wire extending outside the first solar cell, and the other bus
bar is contacted and connected with the tail wire extending outside
the Nth solar cell; and extend directions of the two bus bars are
both different from the first direction.
13. The photovoltaic module according to claim 11, wherein in the
first direction, an absolute value of a difference between a total
length of the N solar cells and a length of the first adhesive
layer is less than or equal to 100 mm and an absolute value of a
difference between a length of the second adhesive layer and a
total length of the N solar cells is less than or equal to 60
mm.
14. The photovoltaic module according to claim 11, wherein in a
direction perpendicular to the first direction, the first adhesive
layer has a total thickness of 0.1 mm to 0.4 mm, and the second
adhesive layer has a thickness of 0.1 mm to 0.4 mm.
15. The photovoltaic module according to claim 11, wherein
light-receiving surfaces of the N solar cells face a same
direction, and each of the first wires comprises a light-receiving
wire, a connecting wire, and a rear wire that are sequentially
connected, wherein for each first wire of the first wires, the
light-receiving wire of the first wire is disposed on a
light-receiving surface of a corresponding solar cell of the N
solar cells, the rear wire of the first wire is located on a rear
surface of another solar cell of the N solar cells subsequent to
the corresponding solar cell, and the connecting wire of the first
wire is located between the corresponding solar cell of the N solar
cells and the another solar cell, wherein the light-receiving
surface is away from the first adhesive layer.
16. The photovoltaic module according to claim 15, wherein
light-receiving wires on the light-receiving surface of the
corresponding solar cell of the N solar cells are dense grid lines,
the light-receiving surface of the corresponding solar cell of the
N solar cells is provided with subgrid lines arranged at intervals,
and the subgrid lines intersect and contact with the dense grid
lines, wherein the second adhesive layer is disposed on surfaces of
the subgrid lines.
17. The photovoltaic module according to claim 15, wherein 8 to 32
light-receiving wires are laid at intervals on the light-receiving
surface of each of the N solar cells.
18. The photovoltaic module according to claim 11, wherein in the
first direction, an absolute value of a difference between a length
of the head wire and a length of the first solar cell is less than
or equal to 20 mm.
19. The photovoltaic module according to claim 11, wherein in the
first direction, an absolute value of a difference between a length
of any of the first wires and twice the length of any of the solar
cells is less than or equal to 40 mm.
20. The photovoltaic module according to claim 11, wherein the
first substrate is a flexible or rigid substrate with high light
transmittance or high reflectance; the second substrate is made of
at least one of polyethylene terephthalate, tempered glass, and
ethylene-tetrafluoroethylene copolymer; the first encapsulation
layer is made of at least one of polyethylene-polyvinyl acetate
copolymer, polyolefin, and polyvinyl butyral; and the second
encapsulation layer is made of at least one of
polyethylene-polyvinyl acetate copolymer, polyolefin, and polyvinyl
butyral.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent
application Ser. No. 17/322,885, filed on May 17, 2021, which
claims the benefit of priority to Chinese Patent Application No.
202110246919.9 filed on Mar. 5, 2021, each of which is incorporated
herein by reference in its entirety.
TECHNICAL FIELD
[0002] Embodiments of the present disclosure relate to the
photovoltaic field, in particular to a solar cell string, a
photovoltaic module and manufacturing methods therefor.
BACKGROUND
[0003] As the issues of energy shortages and environment
deterioration become increasingly serious, solar energy has
received more and more attention as a green and renewable energy
source. The photovoltaic module is a device that converts renewable
solar energy into electrical energy.
[0004] The photovoltaic module is usually composed of multiple
solar cell strings, and the solar cell string is usually composed
of multiple solar cells connected in series. The process of
connecting multiple solar cells in series to form a solar cell
string is called as a solar cell interconnection process. The
performance of the photovoltaic module is related to the
development of the solar cell interconnection process.
[0005] However, it is still desired to improve the current solar
cell interconnection process, as well as the performance of the
photovoltaic module.
SUMMARY
[0006] A solar cell string is provided. The solar cell string
includes: a first adhesive layer, where the first adhesive layer
includes N placement regions sequentially arranged along a first
direction, and the N is a positive integer greater than 1; N solar
cells, where each of the N solar cells is disposed on a
corresponding placement region of the N placement regions; first
wires, where the first wires are laid on a surface of at least one
of the N solar cells away from the first adhesive layer, and the
first wires stretch across adjacent placement regions to
electrically connect adjacent solar cells; and a second adhesive
layer, wherein the second adhesive layer is disposed on the surface
of at least one of the N solar cells away from the first adhesive
layer, the first wires are located between the second adhesive
layer and the at least one of the N solar cells, and the first
adhesive layer, the first wires, the N solar cells, and the second
adhesive layer are bonded and fixed.
[0007] A photovoltaic module is further provided. The photovoltaic
module includes a first substrate, a first encapsulating layer, the
solar cell string described above, a second encapsulating layer,
and a second substrate are stacked in sequence.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] One or more embodiments are exemplified by the figures in
the corresponding drawings. These exemplified descriptions do not
constitute a limitation on the embodiments. Unless otherwise
stated, the figures do not constitute a scale limitation.
[0009] FIGS. 1 and 2 are schematic structural diagrams
corresponding to each step in an interconnection technology.
[0010] FIGS. 3 to 11 are schematic structural diagrams
corresponding to each step in a method for manufacturing a solar
cell string according to an embodiment of the present
disclosure.
[0011] FIGS. 12 to 13 are schematic structural diagrams
corresponding to each step in a method for manufacturing a solar
cell string according to another embodiment of the present
disclosure.
[0012] FIG. 14 is a schematic structural diagram corresponding to a
method for manufacturing a photovoltaic module according to the
present disclosure.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0013] As noted, it is still desired to improve the current solar
cell interconnection process, as well as the performance of the
photovoltaic module.
[0014] The inventors found, for an interconnection process in which
the solar cells are interconnected to form the photovoltaic module
by welding a welding strip, the welding temperature is excessive
high and the welding stress is excessive large.
[0015] An interconnection technology, called as the Smart wire
interconnection technology, has been developed, to avoid adverse
effects of welding on photovoltaic modules. FIGS. 1 and 2 are
schematic structural diagrams corresponding to each step in the
Smart wire interconnection technology, and FIG. 1 is a
cross-sectional view of a flexible electrical connection layer.
[0016] As shown in FIG. 1, the flexible electrical connection layer
34 is prefabricated. The flexible electrical connection layer 34 is
prepared by a double-layer structured polymer film composed of an
adhesive layer 31 and a support layer 32, and metal wires 33
through a hot pressing method.
[0017] During the preparation process of the flexible electrical
connection layer 34, in order to prevent the adhesive layer 31 from
sticking to production equipment, the support layer 32 is required
to isolate the adhesive layer 31 from the production equipment.
Therefore, the flexible electrical connection layer 34 has to be a
double-layer structure. However, when the subsequent flexible
electrical connection layer 34 is laid on a light-receiving surface
of a solar cell, the double-layer structure would reduce the light
absorption rate of the solar cell.
[0018] As shown in FIG. 2, after the flexible electrical connection
layer 34 is cut into flexible electrical connection layer units,
the solar cells 30 are connected in series one another.
Subsequently, the solar cell string is processed by hot pressing or
the like, and the flexible electrical connection layers 34 at a
head portion and a tail portion of the solar cell string are
specially processed, so that the metal wires 33 are exposed to
facilitate subsequent connection with a bus bar to collect
electrical current.
[0019] In the Smart wire interconnection technology, although the
series welding is eliminated, steps for prefabricating the flexible
electrical connection layer 34 and cutting the flexible electrical
connection layer 34 are still required. In addition, the flexible
electrical connection layers 34 at the head portion and the tail
portion of the solar cell string need to be specially processed,
which increases the complexity of the process and also cause a
potential bottleneck in mass production. Further, due to the
difference between the Smart wire interconnection technology and
the conventional welding-interconnection technology, the original
welding equipment may not meet the preparation requirements of the
solar cell string under the Smart wire interconnection technology.
Therefore, it is necessary to carry out the development of new
equipment, such as the development of production equipment for
flexible electrical connection layers. The development of new
equipment has a risk of failure and may further increase production
costs.
[0020] In order to solve the above problems, some embodiments of
the present disclosure provide a method for manufacturing a solar
cell string, including: providing a first adhesive layer, where
each placement region of the first adhesive layer is used to bond
and fix a corresponding solar cell; placing the solar cell on the
placement region; laying first wires on a surface of at least one
solar cell of the N solar cells away from the first adhesive layer,
and stretching the first wires across adjacent placement regions to
electrically connect two adjacent solar cells; disposing a second
adhesive layer on the surface of the solar cell away from the first
adhesive layer; performing a pressing treatment to bond and fix the
first adhesive layer, the first wires, the at least one solar cell
of the N solar cells and the second adhesive layer. In this way,
the solar cells are directly electrically connected through the
first wires, and the interconnection between the solar cells may be
realized without a prefabricated flexible electrical connection
layer, so there is no need to adopt the production equipment of
flexible electrical connection layer. In addition, since there is
no need to use the welding interconnection technology, the adverse
effects of high welding temperature and welding stress on the solar
cell string may be avoided. Furthermore, after the pressing
treatment, the first adhesive layer and the second adhesive layer
may bond the first wires, so that the first wires are fixed on the
surface of the solar cells. Therefore, the performance of the solar
cell string can be improved, the production process of the solar
cell string can be simplified, and the production cost can be
reduced.
[0021] The embodiments of the present disclosure will be described
in detail below with reference to the accompanying drawings in
order to make the objectives, technical solutions and advantages of
the present invention clearer. However, it will be understood by
those skilled in the art that, in the various embodiments of the
present invention, numerous technical details are set forth in
order to provide the reader with a better understanding of the
present disclosure. However, the technical solutions claimed in the
present disclosure can be implemented without these technical
details and various changes and modifications based on the
following embodiments.
[0022] Some embodiments of the present disclosure provide a method
for manufacturing a solar cell string. FIGS. 3 to 11 are schematic
structural diagrams corresponding to each step in the method for
manufacturing a solar cell string. The following will be described
in detail with reference to the accompanying drawings.
[0023] Referring to FIG. 3, a first adhesive layer 11 is provided.
The first adhesive layer 11 includes N placement regions A
sequentially arranged along a first direction X, each of the
placement region A is used to bond and fix a corresponding solar
cell, and the N is a positive integer greater than 1.
[0024] The first adhesive layer 11 is used to place N solar cells,
and each of the solar cells is located on a corresponding placement
region A.
[0025] In an embodiment, the first adhesive layer 11 is hot melt
adhesive, and the subsequent pressing treatment includes a heating
treatment. Since the hot melt adhesive has good thermal bonding
performance and thermal stability, under certain temperature
conditions, the hot melt adhesive may tightly bond the first wires,
head wires and tail wires that may be laid later on the solar cell,
so as to form an integrated structure. Further, the electrical
connection effect of the first wires, the head wires, and the tail
wires with the solar cells in the subsequent lamination treatment
is good.
[0026] In an embodiment, the material of the first adhesive layer
11 may be any of silicone resin, epoxy resin, polyurethane, acrylic
acid, ionomer, polyethylene terephthalate, polyvinyl chloride,
polycarbonate and ethylene-vinyl acetate and any combination with
hot melting properties.
[0027] In an embodiment, the first adhesive layer may be a UV
(Ultraviolet) curing adhesive, and the subsequent pressing
treatment includes an ultraviolet irradiation treatment. Under the
irradiation of ultraviolet light, the first adhesive layer is cured
and may tightly bonds the solar cells with the first wires, the
head wires and the tail wires.
[0028] In an embodiment, the material of the first adhesive layer
may be any of silicone resin, epoxy resin, polyurethane, acrylic
acid, polyvinyl butyral and polycarbonate and any combination
thereof with UV curing properties.
[0029] In an embodiment, the first adhesive layer 11 has a
double-layer structure, and includes an adhesive layer 111 and a
supporting layer 112 stacked in sequence, and the adhesive layer
111 is located between the supporting layer 112 and the solar cell
to be subsequently disposed.
[0030] The adhesive layer 111 has good ductility and adhesiveness,
and may improve the effect of adhesion. The material of the
adhesive layer 111 may be the above-mentioned hot melt adhesive or
UV curing adhesive. The supporting layer 112 has good thermal
stability. In the subsequent pressing treatment, the supporting
layer 112 may protect the adhesive layer 111 and further improve
the effect of adhesion. The material of the supporting layer 112
may be any of polyethylene terephthalate, polyvinyl chloride,
polycarbonate, nylon, any combination thereof and other
materials.
[0031] The first adhesive layer 11 has a total thickness of 0.1 mm
to 0.4 mm in the direction vertical to the first adhesive layer,
for example, 0.15 mm, 0.2 mm, and 0.3 mm. When the total thickness
of the first adhesive layer 11 is within the above range, the total
thickness of the solar cell string may be kept within a small value
range, and the first adhesive layer 11 has sufficient mechanical
strength to avoid damage to the first adhesive layer 11. In some
embodiments, the thickness of the adhesive layer 111 may be 50
.mu.m to 300 .mu.m, such as 100 .mu.m, 150 .mu.m, or 200 .mu.m; the
thickness of the support layer 112 may be 50 .mu.m to 300 .mu.m,
such as 100 .mu.m, 150 .mu.m, or 200 .mu.m.
[0032] When laying the first adhesive layer 11, the adhesive layer
111 shall face to the solar cells, and the support layer 112 shall
face away from the solar cells.
[0033] In the first direction X, the length of the first adhesive
layer 11 is approximately equal to the length of the solar cell
string to be prepared. When the difference between the length of
the first adhesive layer 11 and the length of the solar cell string
is small, the contact region between the first adhesive layer 11
and the solar cells may be increased, thereby improving the
firmness of the adhesion. Further, in the first direction X, the
absolute value of the difference between the total length of the N
solar cells and the length of the first adhesive layer 11 is less
than or equal to 100 mm. It is understandable that in the first
direction X, the total length of the N solar cells may be greater
than, equal to, or less than the length of the first adhesive layer
11.
[0034] In an embodiment, in order to facilitate the preparation of
the solar cell string, a laying platform may be provided. The first
adhesive layer 11 is provided on the laying platform, and a release
film is provided between the laying platform and the first adhesive
layer 11. After the solar cell string is formed, the release film
is removed. The release film is used to isolate the laying platform
from the first adhesive layer 11 to prevent the first adhesive
layer 11 from adhering to the laying platform.
[0035] In an embodiment, the operating temperature of the release
film is 120 to 300.degree. C., the release force of the release
film is 5 G to 50 G, and the thickness of the release film is 25
.mu.m to 300 .mu.m. The release film may be single-sided or
double-sided release film that has polyethylene, polyethylene
terephthalate, stretchable polypropylene, biaxially stretched
polypropylene film, polyvinyl chloride, polycarbonate or polyvinyl
or any combination thereof as base material.
[0036] Referring to FIG. 4, a solar cell 10 is placed on a
placement region A.
[0037] In an embodiment, the solar cell 10 is an N-type solar cell,
such as a full-back electrode contact solar cell, a heterojunction
solar cell, or a passivated contact solar cell. In other
embodiments, the solar cell may be a P-type solar cell. The
foregoing solar cell types are only examples, and this embodiment
does not limit the specific types of solar cells.
[0038] In an embodiment, the solar cell 10 is a single solar cell.
In other embodiments, the solar cell may include several slices,
e.g., any of 2-12 slices.
[0039] The surface of the solar cell 10 has at least one layer of
electrically conductive anti-reflection optically transparent film
(not shown) and/or at least one layer of insulating anti-reflection
optically transparent film (not shown), to reduce the reflectivity
of light.
[0040] The solar cell 10 is firstly placed in the first placement
region A, that is, the solar cell string includes the first solar
cell 101 at the head portion.
[0041] Before placing the first solar cell 101, the head wires 12
are laid on the first adhesive layer 11. The head wires 12 are
located between the first adhesive layer 11 and the first solar
cell 101, and the head wires 12 extend outside the first solar cell
101.
[0042] In an embodiment, the laying method of the head wires 12 is
as follows: using a clamp to fix head portions of the head wires
12, and the fixed head portions are located outside the first
adhesive layer 11; using a guide rail to lay the head wires 12 in
parallel on the first adhesive layer 11; fixing tail portions of
the head wires 12 by using a clamp when the guide rail pulls the
tail portions of the head wires 12 to the tail portion of the first
placement region A. In this way, the head wires 12 can be arranged
on the first adhesive layer 11 in parallel and uniformly.
[0043] Later, a bus bar may be used. The bus bar is contacted and
connected with the heads portions of the head wires outside the
first solar cell 101, so as to collect the electrical current of
the solar cell string. That is, the head wires 12 extend outside
the first adhesive layer 11. Compared with the case where a
prefabricated flexible electrical connection layer is used, this
embodiment does not require special treatment on the head portion
of the first adhesive layer 11 and the head wires 12. The exposed
head wires 12 may be directly connected with the bus bar, thus
simplifying the production process and reducing the production
cost.
[0044] In an embodiment, in the first direction X, an absolute
value of a difference between the length of the head wire 12 and
the length of the solar cell 10 is less than or equal to 20 mm.
Since the length of the head wire 12 is close to the length of the
solar cell 10, the head wires 12 have a large contact region with
the solar cell 10, so that the head wires 12 may fully collect the
electrical current generated by the solar cell 10.
[0045] The shape and material of the head wire 12 are similar to
the shape and material of the first wire laid later. More details
may be referred to in the detailed description of the first wire
below.
[0046] Referring to FIG. 5, first wires 13 are laid on a surface of
the first solar cell 101 away from the first adhesive layer 11. The
first wire 13 stretches across the adjacent placement regions A to
electrically connect the two adjacent solar cells 10.
[0047] In this embodiment, the light-receiving surface F of each
solar cell 10 faces the same direction, that is, in the figures,
all light-receiving surfaces F face upwards, and all rear surfaces
B face downwards.
[0048] The first wire 13 will be described in detail below.
[0049] The first wire 13 includes a light-receiving wire 131, a
connecting wire 132, and a rear wire 133 that are sequentially
connected. The method for laying the first wires 13 includes:
laying the light-receiving wires 131 on the light-receiving surface
F of the solar cell 10, where the light-receiving surface F is away
(i.e., facing away) from the first adhesive layer 11; bending the
connecting wires 132 so that the rear wires 133 are located on the
surface of the first adhesive layer 11 of the adjacent placement
region A.
[0050] In an embodiment, the light-receiving wires 131 are dense
grid lines, that is, the light-receiving wires 131 are used as the
main grid lines of the solar cell 10. Compared with the method of
forming the main grid lines by screen printing, the light-receiving
wire s131 serving as the main grid lines may increase the
light-receiving region of the solar cell and reduce the series
resistance. In other embodiments, the light-receiving wires may be
used as connecting lines (rather than the main grid lines) and
connect the main grid lines of the previous solar cell and the rear
surface of the subsequent solar cell.
[0051] Referring to FIGS. 5 and 6 (FIG. 6 is a top view of FIG. 5),
the light-receiving surface F has a plurality of subgrid lines 18
arranged at intervals, and the plurality of subgrid lines 18
intersect and contact with the dense grid lines.
[0052] For each solar cell 10, the light-receiving surface F is
laid with 8 to 32 light-receiving wires 131 at intervals. Due to
the large number of light-receiving wires 131, the current
transmission path in the solar cell 10 may be shortened, and the
internal loss may be reduced.
[0053] The absolute value of the difference between the length of
the first wire 13 and twice the length of the solar cell 10 is less
than or equal to 40 mm. Since the length of the first wire 13 is
close to a total length of two solar cells 10, the first wires 13
has a large contact region with the solar cells 10, so that the
first wires 13 may fully collect the electrical current generated
by the solar cells 10.
[0054] Referring to FIGS. 5 to 7, FIG. 7 is a cross-sectional view
of FIGS. 5 and 6 in a second direction Y, and the second direction
Y is perpendicular to the first direction X. In an embodiment, the
cross section of the first wire 13 is circular, and the sectional
area of the first wire 13 is 0.02 mm.sup.2.about.0.15 mm.sup.2. In
other embodiments, the cross section of the first wire may be any
one of square, triangle, trapezoid, and rectangle.
[0055] In an embodiment, the first wire 13 includes a solder core
and an alloy layer surrounding the solder core. The material of the
alloy layer is low melting point metal, so that the first wires 13
are electrically and physically connected to the subgrid lines 18
on the surface of the solar cell 10 in the subsequent lamination
treatment. In an embodiment, a melting point temperature of the
alloy layer is less than or equal to the process temperature of the
subsequent lamination treatment. In an example, the melting point
temperature of the alloy layer may be 100.degree. C. to 160.degree.
C. The material of the alloy layer may be any of Sn, Pb, Bi, In,
Zn, Cu, Sb, and Ag and any combination thereof.
[0056] In other embodiments, a first conductive layer (the first
wires) may be of a single-layer structure.
[0057] Referring to FIG. 8, a second adhesive layer 14 is disposed
on the surface of the solar cell 10 away from the first adhesive
layer 11, and the first wires 13 are located between the second
adhesive layer 14 and the solar cell 10.
[0058] The second adhesive layer 14 is used to bond the first wires
13 and the solar cell 10. In an embodiment, since the surface of
the solar cell 10 also has subgrid lines 18 (as shown in FIG. 6),
the second adhesive layer 14 is located on the surface of the
subgrid lines 18 in addition to the surface of the first wires
11.
[0059] The second adhesive layer 14 on the surface of the solar
cell 10 may either be a piece of film, or separate films to ensure
that each film covers a corresponding first wire 13. The separate
films are conductive to reducing the region where the second
adhesive layer 14 blocks the light-receiving surface of the solar
cell 10, thereby further improving the light absorption capacity of
the solar cell 10.
[0060] In an embodiment, the second adhesive layer 14 is hot melt
adhesive, and the subsequent pressing treatment includes a heating
treatment. In other embodiments, the second adhesive layer is a UV
curable adhesive, and the subsequent pressing treatment includes an
ultraviolet irradiation treatment. The material of the second
adhesive layer 14 is the same as the material of the first adhesive
layer 11, and more details can be referred to the relevant
description of the first adhesive layer 11, which will not be
repeated here.
[0061] In an embodiment, the second adhesive layer 14 is of a
single-layer structure, that is, the second adhesive layer 14 is an
adhesive layer. Compared with a double-layer structure, the second
adhesive layer 14 with the single-layer structure may increase the
light transmittance to increase the light absorption rate of the
solar cell 10. In addition, the second adhesive layer 14 with the
single-layer structure is lighter and thinner, which can reduce the
thickness and weight of the solar cell string. In other
embodiments, the second adhesive layer may be of a double-layer
structure.
[0062] The material properties of the second adhesive layer 14 may
be the same as the material properties of the first adhesive layer
11, that is, both are hot melt adhesive or both are UV curing
adhesive. In this way, the material properties of the first
adhesive layer 11 and the second adhesive layer 14 may be changed
simultaneously in the same pressing treatment, so that the first
adhesive layer 11 and the second adhesive layer 14 have adhesive
properties.
[0063] The second adhesive layer 14 has a thickness of 0.1 mm to
0.4 mm in a direction vertical to the second adhesive layer (e.g.,
in a direction vertical to the first direction X), for example, 0.2
mm, 0.25 mm, or 0.3 mm. When the thickness of the second adhesive
layer 14 is within the above range, the weight and thickness of the
solar cell string may be kept within a small value range, and a
large adhesive force may be provided.
[0064] In the first direction X, the absolute value of the
difference between the length of the second adhesive layer 14 and
the length of the solar cell 10 is less than or equal to 60 mm.
When the difference between the length of the second adhesive layer
14 and the length of the solar cell 10 is small, the contact region
between the second adhesive layer 14 and the solar cell 10 may be
increased, thereby improving the firmness of adhesion.
[0065] The pressing treatment is performed to fix the first
adhesive layer 11, the first wires 13, the head wires 12, the solar
cell 10, and the second adhesive layer 14. In an embodiment, the
surface of the first adhesive layer 11 and the surface of the
second adhesive layer 14 are applied with a certain pressure, and
the first adhesive layer 11, the first wires 13, the head wires 12,
the solar cell 10, and the second adhesive layer 14 are tightly
bonded through specific conditions such as heating treatment or
ultraviolet radiation treatment to form an integrated
structure.
[0066] In an embodiment, the material of the first adhesive layer
11 and the second adhesive layer 14 is hot melt adhesive,
correspondingly, the pressing treatment includes a heating
treatment. In an embodiment, the material of the first adhesive
layer and the second adhesive layer is UV curable adhesive,
correspondingly, the pressing treatment includes an ultraviolet
irradiation treatment. In an embodiment, the material of the first
adhesive layer and the second adhesive layer is a composite
material of hot melt adhesive and UV curing adhesive, and
correspondingly, the pressing treatment includes the heating
treatment and the ultraviolet radiation treatment.
[0067] Referring to FIG. 9, the steps of placing the solar cell 10,
laying the first wires 13, disposing the second adhesive layer 14
and performing the pressing treatment are repeated until the first
wires 13 are laid on the placement region A at the tail portion of
the solar cell string.
[0068] Referring to FIG. 10, the Nth solar cell 102 is placed on
the placement region A at the tail portion of the solar cell
string, that is, the solar cell string includes the Nth solar cell
102 at the tail portion.
[0069] After placing the Nth solar cell 102, tail wires 15 are laid
on the surface of the Nth solar cell 102 away from the first
adhesive layer 11, and the tail wires 15 extend outside the Nth
solar cell 102. The tail wires 15 are arranged in parallel on the
upper surface of the Nth solar cell 102.
[0070] Further, a second adhesive layer 14 is disposed on the
surface of the Nth solar cell 102 away from the first adhesive
layer 11. The detailed description of the second adhesive layer 14
may be referred to the aforementioned corresponding description,
and will not be repeated here.
[0071] The pressing treatment is performed. The Nth solar cell 102,
the first adhesive layer 11, the first wires 13, the tail wires 15,
and the second adhesive layer 14 are fixed under certain pressure
conditions and through specific conditions such as heating
treatment or ultraviolet radiation treatment.
[0072] In an embodiment, after laying a solar cell 10, a lamination
treatment is performed, and the number of lamination treatments is
the same as the number of solar cells 10, so that the position of
the head wires 12, the tail wires 15 and the first wires 13 can be
relatively fixed with the solar cell 10, and the laying of the
latter solar cell 10 may not change the relative position of the
former solar cell 10 and the aforementioned wires.
[0073] In an embodiment, a lamination treatment may be performed
after all the solar cells are laid. In an embodiment, a lamination
treatment may be performed after two adjacent solar cells are laid,
and thus the number of lamination treatments is equal to one-half
of the number of solar cells.
[0074] Later, a bus bar is used to contact and connect with the
tail wires 15 extending outside the Nth solar cell 102, so as to
collect the electrical current of the solar cell string. Since the
tail wires 15 extend outside the second adhesive layer 14, compared
to the case where a prefabricated flexible electrical connection
layer is used, this embodiment does not require special treatment
on the second adhesive layer 14 located at the tail portion of the
solar cell string and the tail wires 15, and the exposed tail wires
15 may be directly connected to the bus bar subsequently, thus
simplifying the production process and reducing the production
cost.
[0075] Referring to FIG. 11, at least two bus bars 19 are provided.
One bus bar 19 is contacted or connected with the head wires 12
(refer to FIG. 10) extending outside the first solar cell 101, and
the other bus bar 19 is contacted or connected with the tail wires
15 (refer to FIG. 10) extending outside the Nth solar cell 102. The
extending directions of the bus bars 19 are different from the
first direction X.
[0076] That is, one bus bar 19 is connected with all the head wires
12, and the other bus bar 19 is connected with all the tail wires
15, so as to realize the collection of the electrical current in
the solar cell string.
[0077] In an embodiment, the connection between the head wires 12,
the tail wires 15 and the bus bars 19 is achieved by lamination. In
other embodiments, the connection between the head wires, the tail
wires and the bus bars may be achieved by welding.
[0078] To sum up, the first wires 13, the head wires 12 and the
tail wires 15 are directly electrically connected to the solar
cells 10, and the interconnection among the solar cells 10 is
realized without a prefabricated flexible electrical connection
layer. Therefore, the difficulty of equipment development may be
significantly reduced. Further, the methods can be realized on the
basis of an existing stringer by adding a conveying mechanism for
the first adhesive layer 11 and a laying mechanism for the second
adhesive layer 14. Besides, in the above methods, there is no need
to perform special treatment on the adhesive layer 11 at the head
portion of the solar cell string and the second adhesive layer 14
at the tail portion of the solar cell string. Just the head wires
12 and the tail wires 15 are required to be exposed by extending
the head wires 12 and the tail wires 15 outside the solar cell 10.
In addition, in the above methods, the electrical connection
between the first wires 13 and the solar cells 10 may be realized
without welding, so adverse effects of high welding temperature and
welding stress on the solar cells 10 may be avoided. Further, every
time a solar cell 10 is laid, a lamination treatment is performed,
so that the first wires 13 and the solar cell 10 may be hold in
relatively fixed positions. Therefore, the above methods may
simplify the production process, reduce the production cost, and
improve the performance of the solar cell string.
[0079] Some embodiments of the present disclosure further provide
another method for manufacturing a solar cell string. This
embodiment is roughly the same as the previous embodiments. The
main difference is that the light-receiving surfaces of adjacent
solar cells in latter embodiments face opposite directions, so that
the laying method for the first wires and the second adhesive layer
is different from that of the previous embodiments. FIGS. 12 and 13
are schematic structural diagrams corresponding to each step in the
manufacturing method provided by latter embodiments, which will be
described in detail below with reference to the accompanying
drawings.
[0080] Referring to FIG. 12, a first adhesive layer 21 is provided.
The first adhesive layer 21 includes N placement regions A
sequentially arranged along the first direction X, and each
placement region A is used to bond and fix a corresponding solar
cell 20, and the N is a positive integer greater than 1.
[0081] In an embodiment, the first adhesive layer 21 is of a
double-layer structure including an adhesive layer 211 and a
supporting layer 212. In other embodiments, the first adhesive
layer may be of a single-layer structure.
[0082] The detailed description of the first adhesive layer 21 and
the solar cell 20 may be referred to the previous embodiment, which
will not be repeated here.
[0083] Solar cells 20 are placed on placement regions A. All the
solar cells 20 are laid, and the light-receiving surfaces F of
adjacent solar cells 20 face opposite directions. That is, for the
adjacent solar cells 20, the light-receiving surface F of one solar
cell 20 faces upward, and a rear surface B of the next solar cell
20 faces upward.
[0084] Before placing the solar cells 20 on the placement region A,
second wires 22 are laid on the surface of the first adhesive layer
21, and the second wires 22 stretch across the adjacent placement
regions A to electrically connect two adjacent solar cells 20.
[0085] In an embodiment, the second wires 22 are also electrically
connected to all the solar cells 20 of the solar cell string.
[0086] In an embodiment, the second wires 22 located at the head
portion of the solar cell string extend outside the solar cell 20,
and further electrically connect to a bus bar to collect the
electrical current in the solar cell string. In other embodiments,
the second wires at the tail portion of the solar cell string
extend outside the solar cell and are electrically connected to the
bus bar.
[0087] Since the second wires 22 extending outside the solar cell
20 are exposed to the first adhesive layer 21, there is no need to
perform special treatment on the first adhesive layer 21 to expose
the second wires 22, thereby simplifying the production
process.
[0088] Referring to FIG. 13, first wires 23 are laid on the surface
of the solar cell 20 away from the first adhesive layer 21. The
first wires 23 stretch across the adjacent placement region A
(refer to FIG. 12) to electrically connect two adjacent solar cells
20.
[0089] In an embodiment, the first wires 23 are electrically
connected to all the solar cells 20.
[0090] The first wires 23 at the tail portion of the solar cell
string extend outside the solar cell 20, and are further
electrically connected to the bus bar to collect the electrical
current in the solar cell string. In other embodiments, the second
wires at the head portion of the solar cell string extend outside
the solar cell and are electrically connected to the bus bar.
[0091] Further, a second adhesive layer 24 is disposed on the
surface of the solar cells 20 away from the first adhesive layer
21, and the first wires 23 are located between the second adhesive
layer 24 and the solar cells 20.
[0092] The pressing treatment is performed to bond and fix the
first adhesive layer 21, the first wires 23, the second wires 22,
the solar cells 20, and the second adhesive layer 24. The pressing
treatment may be performed to tightly bond the above-mentioned
structures through specific conditions such as pressure, high
temperature, or ultraviolet radiation to form an integrated
structure.
[0093] The light-receiving surfaces of adjacent solar cells 20 face
different directions, so there is no need to bend the first wires
23. A single first wire 23 may connect all the solar cells 20, and
a single second wire 22 may also connect all the solar cells 20,
and there is no need to additionally provide head wires and tail
wires. In addition, the lamination treatment may be performed after
all the solar cells 20 are laid, thus reducing the frequency of
laminations and improving production efficiency. Therefore, the
production process is simplified and the production cost is
reduced.
[0094] Some embodiments of the present disclosure also provide a
solar cell string which may be manufactured by the manufacturing
methods provided in the foregoing embodiment. FIGS. 10 and 11 are
schematic diagrams of the solar cell string as provided.
[0095] Referring to FIGS. 10 and 11, the solar cell string
includes: a first adhesive layer 11, N solar cells 10, first wires
13 and second adhesive layers 14. The first adhesive layer 11
includes N placement regions A sequentially arranged along a first
direction X, and the N is a positive integer greater than 1. Each
of the solar cells 10 is disposed on a corresponding placement
region A. The first wires 13 are laid on a surface of the solar
cell 10 away from the first adhesive layer 11, and the first wires
13 stretch across the adjacent placement region A to electrically
connect two adjacent solar cells 10. The second adhesive layers 14
are respectively disposed on the surfaces of the solar cells 10
away from the first adhesive layer 11. The first wires 13 are
located between the second adhesive layer 14 and the solar cell 10.
The first adhesive layer 11, the first wires 13, the solar cells 10
and the second adhesive layers 14 are bonded and fixed.
[0096] A detailed description will be given below with reference to
the accompanying drawings.
[0097] Referring to FIG. 10, in an embodiment, the light-receiving
surfaces F of the solar cells 10 in the solar cell string face the
same direction, that is, all the light-receiving surfaces F face
upward (in a direction away from the first adhesive layer 11), and
all the rear surfaces B face downward. The solar cell string
includes a first solar cell 101 at a head portion and an N-th solar
cell 102 at a tail portion respectively. Detailed description of
the solar cell 10 may be referred to the description of the
foregoing embodiments, which will not be repeated here.
[0098] The first wires 13 are used to electrically connect two
adjacent solar cells 10. In an embodiment, each first wire 13
includes a light-receiving wire, a connecting wire, and a rear wire
that are sequentially connected. The light-receiving wire is
located on the light-receiving surface F of a solar cell 10, the
rear wire is located on the rear surface B of a next solar cell 10,
and the connecting wire is located between the adjacent solar cells
10.
[0099] The solar cell string further includes: head wires 12
located between the first adhesive layer 11 and the first solar
cell 101 and extending outside the first solar cell 101. The head
wires 12 extend outside the first solar cell 101 and are exposed to
the first adhesive layer 11.
[0100] The solar cell string further includes: tail wires 15
located on the surface of the Nth solar cell 102 away from the
first adhesive layer 11 and extending outside the Nth solar cell
102. The second adhesive layer 14 is disposed on the surface of the
Nth solar cell 102 away from the first adhesive layer 11. The tail
wires 15 extend outside the Nth solar cell 102 and are exposed to
the second adhesive layer 14.
[0101] Referring to FIGS. 10 and 11, the solar cell string further
includes at least two bus bars 19. One of the bus bars 19 is
contacted and connected with the head wires 12 extending outside
the first solar cell 101, the other bus bar 19 is contacted and
connected with the tail wire 15 extending outside the Nth solar
cell to contact and connect, and the extend directions of the bus
bars 19 are different from the first direction X.
[0102] Detailed descriptions of the first wire 13, the head wire 12
and the tail wire 15 may be referred to the foregoing embodiments,
which will not be repeated here.
[0103] As shown in FIG. 10, the first adhesive layer 11 is used to
bond and fix all the solar cells 10 of the solar cell string. In
the first direction X, the length of the first adhesive layer 11 is
approximately equal to the length of the solar cell string to be
prepared. When the difference between the length of the first
adhesive layer 11 and the length of the solar cell string 10 is
small, the contact region between the first adhesive layer 11 and
the solar cells 10 may be increased, thereby improving the firmness
of adhesion. Further, in the first direction X, the absolute value
of the difference between the total length of the N solar cells 10
and the length of the first adhesive layer 11 is less than or equal
to 100 mm.
[0104] The first adhesive layer 11 is also used to bond and fix the
first wires 13 and the head wires 12 on the surface of the solar
cell 10 to ensure that the wires are uniformly arranged, so that
the wires may fully collect the electrical current generated in the
solar cell 10.
[0105] The first adhesive layer 11 includes a supporting layer 112
and an adhesive layer 111, and the adhesive layer 111 is located
between the supporting layer 112 and the solar cells 10. Detailed
descriptions of the supporting layer 112 and the adhesive layer 111
may be referred to the foregoing embodiments.
[0106] An individual second adhesive layer 14 corresponds to a
solar cell 10 for fixing the first wires 13 or the tail wires 15 on
the surface of the solar cell 10.
[0107] In the first direction X, the absolute value of the
difference between the length of the second adhesive layer 14 and
the length of the corresponding solar cell 10 is less than or equal
to 60 mm. When the difference between the length of the second
adhesive layer 14 and the length of the corresponding solar cell 10
is small, the contact region between the second adhesive layer 14
and the corresponding solar cell 10 may be increased, thereby
improving the firmness of adhesion.
[0108] In an embodiment, the second adhesive layer 14 has a
single-layer structure. Compared with a double-layer structure, the
single-layer structure has better light transmittance and may
increase the light absorption rate of the solar cell 10.
[0109] In an embodiment, the second adhesive layer 14 is a piece of
film for an individual solar cell 10. That is, the second adhesive
layer 14 not only covers the surface of the solar cell 10
corresponding to the first wires, but also covers the surface of
the solar cell 10 between adjacent first wires 13. In this way, the
coverage region of the second adhesive layer 14 may be increased,
so as to increase the firmness of adhesion and prevent the first
wires 13 from shifting.
[0110] In an embodiment, there are a plurality of first wires and
the second adhesive layer has discrete film structures for an
individual solar cell. That is, each discrete film structure is
provided above the corresponding first wire. In other words, the
second adhesive layer only covers the surface of the solar cell
corresponding to the first wire, and the second adhesive layer does
not cover the surface of the solar cell between adjacent first
wires. The reduction of the coverage region may increase the
light-absorbing ability of the solar cell.
[0111] Since the head wires 12 and the tail wires 15 are exposed to
the first adhesive layer 11 and the second adhesive layer 14
respectively, there is no need to perform special treatment on the
first adhesive layer 11 and the second adhesive layer 14 before
respectively connecting the head wires 12 and the tail wires 15
with the bus bars 19 (refer to FIG. 11). The exposed head wires 12
and tail wires 15 may be directly connected to the bus bars 19
respectively.
[0112] In other embodiments, referring to FIG. 13, the
light-receiving surfaces F of adjacent solar cells 20 in the solar
cell string face different directions. That is, for adjacent solar
cells 20, the light-receiving surface F of one solar cell 20 faces
upward, and the light-receiving surface F of the next solar cell 20
faces downward. The first wires 23 are located on one side of all
the solar cells 20 and electrically connected to all the solar
cells 20. The second wires 22 are located on the other side of all
the solar cells 20 and electrically connected to all the solar
cells 20. The second adhesive layer 24 covers all the solar cells
20.
[0113] In summary, in the above embodiments, there is no need to
perform special treatment on the first adhesive layer 11 at the
head portion of the solar cell string and the second adhesive layer
14 at the tail of the solar cell string. The head wires 12 and the
tail wires 15 may be exposed only by respectively extending the
head wires 12 and the tail wires 15 outside the solar cell 10. In
addition, in the above embodiments, the electrical connection
between the first wires 13 and the solar cells 10 may be realized
without welding, so that the adverse effects of high welding
temperature and welding stress on the solar cell 10 may be
avoided.
[0114] Some embodiments of the present disclosure also provide a
method for manufacturing a photovoltaic module. FIG. 14 is a
schematic structural diagram corresponding to a manufacturing
method as provided. A detailed description will be given below with
reference to the accompanying drawings.
[0115] Referring to FIG. 14, a solar cell string 1 is provided, and
the solar cell string 1 is any one as provided in the foregoing
embodiments. The solar cell string 1 includes solar cells 10, head
wires 12, first wires 13, tail wires 15, a first adhesive layer 11,
and second adhesive layers 14. The first adhesive layer 11 is of a
double-layer structure including an adhesive layer 111 and a
supporting layer 112. The second adhesive layer 14 is of a
single-layer structure.
[0116] As shown in FIG. 14, a first substrate 171, a first
encapsulating layer 161, the solar cell string 1, a second
encapsulating layer 162, and a second substrate 172 are stacked in
sequence to form a stacked structure.
[0117] There may be one or more solar cell strings 1. If there are
multiple solar cell strings 1, a bus bar is used to electrically
and physically connect the multiple solar cell strings 1. In an
embodiment, the bus bar may be connected to the solar cell strings
1 by welding or hot pressing. The multiple solar cell strings 1 may
be arranged in parallel.
[0118] The bus bar is made of low-resistivity material which may be
any of Ag, Cu, Ti, Sn, Ni, Al, Au and any combination thereof. The
cross-section of the bus bar may be any of round, square, triangle,
trapezoid, and rectangle. The surface of the bus bar may be coated
with a layer of alloy material with a thickness of 5-100 um. The
alloy material may be any one of Sn, Pb, Bi, In, Zn, Cu, Sb, and Ag
and any combination thereof.
[0119] The first substrate 171 is a flexible or rigid substrate
with high light transmittance or high reflectance, and may be a
single-sided or double-sided fluorine-containing back plate,
toughened glass, ethylene-tetrafluoroethylene copolymer or other
substrate.
[0120] The second substrate 172 is a flexible or rigid substrate
with high light transmittance, and may be made of polyethylene
terephthalate, tempered glass, or ethylene-tetrafluoroethylene
copolymer or other materials.
[0121] The material of the first encapsulation layer 161 is any one
of polyethylene-polyvinyl acetate copolymer, polyolefin, and
polyvinyl butyral and any combination thereof.
[0122] The material of the second encapsulation layer 162 is any
one of polyethylene-polyvinyl acetate copolymer, polyolefin, and
polyvinyl butyral and any combination thereof.
[0123] The lamination treatment is performed on the stacked
structure, and the first wires 13 and the solar cell 10 are
electrically connected during the lamination treatment. The head
wires 12 and the tail wires 15 are also electrically connected to
the respective solar cell 10 during the lamination treatment. Since
the interconnection process with high temperature welding is
eliminated, the welding stress may be reduced in this way, thereby
reducing the risk of the manufacturing process.
[0124] The lamination treatment will be described in details
below.
[0125] The process temperature used in the lamination treatment is
greater than or equal to the melting point temperature of the first
wire 13. In this way, during the lamination treatment, the first
wires 13 are melted so as to achieve electrical connection between
the first wires 13 and the solar cell 10. Further, in an
embodiment, the first wire 13 includes a solder core and an alloy
layer surrounding the solder core, and the process temperature used
in the lamination treatment is greater than or equal to the melting
point temperature of the alloy layer. When the process temperature
is higher than the melting point temperature of the alloy layer,
the alloy layer melts, and the melted alloy layer is electrically
connected to the solar cell 10 under the effect of pressure.
[0126] The alloy layer is made of low melting point metal, and has
a melting point temperature of 100.degree. C. to 160.degree. C.,
for example, 120.degree. C., 130.degree. C., or 150.degree. C. The
material of the alloy layer may be any one of Sn, Pb, Bi, In, Zn,
Cu, Sb, and Ag and any combination thereof.
[0127] In an embodiment, the difference between the process
temperature of the lamination treatment and the melting point
temperature is less than or equal to 30.degree. C. In this
embodiment, the melting point temperature refers to the melting
point temperature of the alloy layer. When the process temperature
is within the above range, the alloy layer may be fully melted,
thereby improving the effect of electrical connection between the
alloy layer and the solar cell 10. In addition, the risk of
cracking of the solar cell string 1 at excessive high temperatures
may also be reduced.
[0128] The material of the solder core is low-resistance metal,
such as Ag, Cu, Ti, Sn, Ni, Al, and Au and any combination thereof.
In other embodiments, the first wire may have a one-layer structure
of the solder core, and the melting point temperature refers to the
melting point temperature of the solder core, that is, the process
temperature of the lamination treatment is greater than or equal to
the melting point temperature of the solder core.
[0129] The process pressure used in the lamination treatment is -50
kPa-200 kPa. When the process pressure is within the above range,
the connection strength between the first wire 13 and the solar
cell 10 may be increased, and the solar cell string 1 may be
prevented from being damaged by excessive pressure. In an
embodiment, the process pressure is -20 kPa-150 kPa.
[0130] To sum up, the lamination treatment is adopted to realize
the electrical connection between the first wires 13 and the solar
cell 10, which may avoid the adverse effects of high welding
temperature and welding stress on the solar cell string 1.
[0131] Some embodiments of the present disclosure also provide a
photovoltaic module. The photovoltaic module as provided may be
manufactured using the photovoltaic module manufacturing method
provided in the previous embodiments. FIG. 14 is a schematic
structural diagram of the photovoltaic module as provided.
[0132] Referring to FIG. 14, the photovoltaic module includes: a
first substrate 171, a first encapsulating layer 161, a solar cell
string 1 as provided in the foregoing embodiments, a second
encapsulating layer 162, and a second substrate 172 stacked in
sequence.
[0133] Detailed description of the photovoltaic module may be
referred to as above, which will not be repeated here.
[0134] Those of ordinary skill in the art can understand that the
above-mentioned embodiments are specific examples for realizing the
present disclosure, and in actual applications, various changes may
be made in form and details without departing from the spirit and
range of the present disclosure. Any person skilled in the art can
make their own changes and modifications without departing from the
spirit and scope of the present disclosure. Therefore, the
protection scope of the present disclosure should be subject to the
scope defined by the claims.
* * * * *