WO2014136204A1 - Solar battery module - Google Patents

Abstract

The purpose of the present invention is to enable an interconnector and finger electrodes to be electrically connected reliably and at a low cost by forming on the surface of a solar battery cell a conductive adhesive layer along a direction orthogonal to the length direction of the finger electrodes and at a non-uniform width. A conductive adhesive layer (3), for electrically connecting a plurality of finger electrodes (1) to each other via an interconnector (2), is intermittently formed in the range in which the interconnector (2) is disposed on the surface of a solar battery module (10).

Description

Solar cell module

The present invention relates to a solar cell module in which a plurality of solar cells are electrically connected via an interconnector.

A solar battery cell constituting a solar battery module includes a plurality of finger electrodes provided on the surface thereof in parallel with each other with a certain distance between each other, and the plurality of finger electrodes are electrically connected by an interconnector. The interconnector is also used for electrical connection between a plurality of solar cells constituting the solar cell module. As a method of connecting the interconnector to each finger electrode, there is a method using a conductive double-sided tape (conductive film) (see, for example, Patent Document 1).

However, conductive double-sided tape is expensive and hinders cost reduction of solar cells. Therefore, it is conceivable that a conductive adhesive is applied to the surface of the solar cell along a direction orthogonal to the longitudinal direction of each finger electrode, and the interconnector is electrically connected to each finger electrode via the conductive adhesive. .

JP 2011-159937 A

However, if the conductive adhesive is applied linearly to the surface of the solar cell along the direction perpendicular to the longitudinal direction of the electrode, a large amount of conductive is required for electrical connection between the interconnector and each electrode. Adhesive is required and the cost cannot be reduced sufficiently. On the other hand, when the amount of the conductive adhesive applied to the surface of the solar battery cell is insufficient, the connection strength between the interconnector and each electrode becomes insufficient.

An object of the present invention is to form an electrically conductive adhesive with a non-uniform width along a direction orthogonal to the longitudinal direction of each electrode, so that the interconnector and each electrode can be electrically connected reliably and at low cost. The object is to provide a solar cell module.

A solar battery cell constituting the solar battery module of the present invention includes a plurality of finger electrodes, an interconnector, and a conductive adhesive layer. The plurality of finger electrodes are formed in parallel with each other with a certain distance between each other on the surface of the solar battery cell in a state of protruding from the surface of the solar battery cell. The interconnector has a band shape with a constant width and is disposed along a direction orthogonal to the longitudinal direction of the plurality of finger electrodes. The conductive adhesive layer is made of a conductive adhesive, and is fixed to the surface of the solar battery cell in a state where the interconnector is electrically connected to the plurality of finger electrodes. The conductive adhesive layer is formed on the surface of the solar cell at a portion including at least the intervals of the plurality of finger electrodes and in a range in which the interconnector is disposed, and the conductive adhesive layer has a certain width or less in the longitudinal direction of the finger electrodes. A first width portion and a second width portion narrower than the first width.

According to this configuration, the interconnector is attached to the surface of the solar cell via the conductive adhesive layer. Since the conductive adhesive layer has a first width portion equal to or less than a certain width of the interconnector and a second width portion narrower than the first width, the conductive adhesive layer has a uniform width over the entire length of the interconnector. The required amount of conductive adhesive is reduced compared to the case where it is formed. Moreover, since a conductive adhesive layer is below the fixed width of an interconnector, the light reception amount of a photovoltaic cell does not reduce.

In this configuration, the first width is preferably 50% or more of the constant width of the interconnector. The interconnector can be reliably bonded to the surface of the solar battery cell.

The second width is preferably 60% or less of the first width. The amount of conductive adhesive applied can be reliably reduced.

Further, the conductive adhesive layer may be a portion where each of the plurality of finger electrodes and the interconnector overlap each other so as not to be continuous in a direction perpendicular to the longitudinal direction of the finger electrodes. The second width becomes 0, and the application amount of the conductive adhesive can be surely reduced.

According to this invention, by forming the conductive adhesive layer with a non-uniform width on the surface of the solar cell along the direction orthogonal to the longitudinal direction of each finger electrode, the interconnector and each electrode can be securely and It can be electrically connected at low cost.

(A) And (B) is the top view and side sectional drawing of the solar cell module which concern on 1st Embodiment of this invention. (A) And (B) is the top view and sectional drawing of the principal part of the photovoltaic cell which comprises the solar cell module. (A) And (B) is a figure explaining the manufacturing method of the photovoltaic cell, (A) and (B) are the top views and sectional drawings which show an application | coating process, (C) and (D) are mounting. The top view and sectional drawing which show a process, (E) and (F) are the top view and sectional drawing which show a sticking process. (A) And (B) is the top view and sectional drawing of the principal part of the photovoltaic cell which comprise the solar cell module which concerns on the 2nd Embodiment of this invention. (A) to (L) are a plan view and a cross-sectional view of a main part of a solar battery cell constituting a solar battery module according to third to eighth embodiments of the present invention. (A) to (C) are plan views of the main part of the solar battery cell constituting the solar battery module according to the embodiment of the present invention.

Hereinafter, a solar cell module according to an embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, a solar cell module 20 includes, for example, a total of nine bus barless solar cells 10 of 3 rows × 3 columns, and a filler layer between a glass plate 21 on the front surface and a back sheet 22 on the back surface. 23.

On the front and back surfaces of each solar cell 10, a plurality of finger electrodes 1 are formed in parallel with each other at regular intervals, and two interconnectors 2 are attached in a direction perpendicular to the finger electrodes 1. Has been. The interconnector 2 electrically connects the plurality of finger electrodes 1 to each other on the front and back surfaces of each solar battery cell 10 and connects one surface of the two solar battery cells 10 arranged in the column direction to the other back surface. Connect between them. The interconnectors 2 of the two solar cells 10 aligned in the row direction at the end in the column direction are connected by a tab line 4.

The interconnector 2 has a band shape with a constant width in a plan view, and is arranged along a direction orthogonal to the longitudinal direction of the finger electrode 1.

As shown in FIG. 2, each finger electrode 1 is formed with at least one pad portion 11 in the middle portion in the longitudinal direction. When the current of the finger electrode 1 is measured, a measurement terminal (not shown) is brought into contact with the pad portion 11. The interconnector 2 is disposed on the pad portion 11 of each finger electrode 1.

A conductive adhesive layer 3 is formed between the pad portions 11 of each finger electrode 1 on the surface of the solar battery cell 10. The conductive adhesive layer 3 is composed of a conductive adhesive applied to the surface of the solar battery cell 10. As an example, the conductive adhesive is obtained by adding conductive particles to a resin having adhesiveness. However, a known conductive adhesive used for semiconductor manufacturing can be used. Each conductive adhesive layer 3 is in contact with each pad portion 11 of two adjacent finger electrodes 1.

The interconnector 2 is affixed to the surface of the solar battery cell 10 with the lower surface in contact with the upper surface of the portion including the pad portion 11 of each finger electrode 1 via each conductive adhesive layer 3.

Each finger electrode 1 is electrically connected via an interconnector 2 that is in contact with the upper surface of the portion including the respective pad portion 11, and via each conductive adhesive layer 3 that is in contact with each pad portion 11. Are electrically connected.

In the direction orthogonal to the longitudinal direction of the finger electrode 1, the conductive adhesive layer 3 is not formed on the pad portion 11, becomes discontinuous on the pad portion 11, and the width of the conductive adhesive layer 3 is one. Not like that. Compared with the case where the conductive adhesive layer 3 is formed with a uniform width over the entire length of the arrangement range of the interconnector 2, the amount of the conductive adhesive applied can be reduced.

At the time of manufacturing a solar cell, first, as shown in FIGS. 3A and 3B, an appropriate amount of conduction is provided between the pad portions 11 of the plurality of finger electrodes 1 on the surface of the solar cell 10 in the coating process. Apply adhesive. The conductive adhesive can be applied using a silk screen or a syringe. At the time of applying the conductive adhesive by the syringe, the conductive adhesive is intermittently discharged while moving the syringe with respect to the solar battery cell 10, or the discharge of the conductive adhesive and the movement of the syringe are repeated.

The conductive adhesive is applied only between the pad portions 11 of the plurality of finger electrodes 1 within a range where the interconnector 2 is disposed on the surface of the solar battery cell 10. Compared with the case where the conductive adhesive is applied over the entire length of the range in which the interconnector 2 is disposed, the application amount is reduced, and the cost can be reduced.

The amount of the conductive adhesive applied between the pad portions 11 is a predetermined height substantially equal to the height of the finger electrode 1 between two adjacent pad portions 11 and is an interconnector for the surface of the solar battery cell 10. This is a necessary and sufficient amount for filling with a predetermined width that can secure a sufficient adhesive strength of 2. The predetermined width should be narrower than the width of the interconnector 2 in order to prevent a decrease in the amount of light received on the surface of the solar battery cell 10.

An appropriate amount of the conductive adhesive is applied between two adjacent pad portions 11 on the surface of the solar battery cell 10 so as to be higher than a predetermined height.

Next, as shown in FIGS. 3C and 3D, the conductive connector on the surface of the solar battery cell 10 was applied to the interconnector 2 in the placing step before the conductive adhesive was cured. At the position, the longitudinal direction is placed perpendicular to the longitudinal direction of the plurality of finger electrodes 1. At this time, the lower surface of the interconnector 2 is in contact with the conductive adhesive.

Finally, as shown in FIGS. 3E and 3F, in the pressing step, the interconnector 2 is pressed from the upper side toward the surface of the solar battery cell 10 over the entire length. When the conductive adhesive having flexibility before curing is pressed through the interconnector 2, the height from the surface of the solar battery cell 10 is reduced and the area on the surface of the solar battery cell 10 is enlarged. Let As a result, the height of the conductive adhesive substantially matches the height of the finger electrode 1, and both ends thereof contact the pad portions 11 of the two finger electrodes 1 adjacent to each other to form the conductive adhesive layer 3.

When the conductive adhesive composing each conductive adhesive layer 3 is cured in this state, the interconnector 2 is a portion including the pad portion 11 in each finger electrode 1 on the lower surface via each conductive adhesive layer 3. Attached to the surface of the solar battery cell 10 while being in contact with the upper surface of the solar cell 10. The plurality of finger electrodes 1 are electrically connected to each other via an interconnector 2. Adjacent finger electrodes 1 are electrically connected via the conductive adhesive layer 3 at the respective pad portions 11. By setting the predetermined width to 30 to 50% of the interconnector, a good connection state between adjacent finger electrodes 1 could be obtained.

As shown to FIG. 4 (A) and (B), the photovoltaic cell 101 which comprises the solar cell module which concerns on the 2nd Embodiment of this invention is between each pad part 11 of the several finger electrode 1 in the surface. The conductive adhesive layers 3 </ b> A and 3 </ b> B are discontinuously formed on the pads 11 along the position where the interconnector 2 is disposed.

The interconnector 2 is affixed to the surface of the solar battery cell 101 by the conductive adhesive layer 3A, and is affixed to each pad part 11 of the plurality of finger electrodes 1 by the conductive adhesive layer 3B. Thereby, the interconnector 2 can be firmly fixed to a predetermined position on the surface of the solar battery cell 101. The plurality of finger electrodes 1 are electrically connected to each other via the conductive adhesive layer 3 </ b> B and the interconnector 2 at each pad portion 11.

Even with this configuration, the interconnector 2 can be kept firmly fixed on the surface of the solar battery cell 101, and compared with the case where the conductive adhesive is applied over the entire length of the area where the interconnector 2 is disposed. The application amount can be reduced.

In addition, also in the photovoltaic cell 10 which comprises the photovoltaic module which concerns on 1st Embodiment, in order to make the fixing state of the interconnector 2 with respect to the surface of the photovoltaic cell 10 more robust, each pad of the several finger electrode 1 It is also conceivable to form a conductive adhesive layer on the portion 11. In this case, by reducing the application of the conductive adhesive between the pad portions 11 and reducing the width of the conductive adhesive layer, an increase in the total amount of the conductive adhesive can be prevented. .

In addition, the back surface side of each photovoltaic cell 10 is configured similarly to the front surface side.

As shown in FIGS. 5A and 5B, the solar battery cell 102 constituting the solar battery module according to the third embodiment of the present invention has a pad portion on any of the plurality of finger electrodes 1 on the surface. I do not have. The solar battery cell 102 is configured by pasting the interconnector 2 after discontinuously forming the conductive adhesive layer 301 along the position of the interconnector 2 between the finger electrodes 1 on the surface.

The interconnector 2 is attached to the surface of the solar battery cell 102 without contacting the finger electrode 1 by the conductive adhesive layer 301. Each of the plurality of finger electrodes 1 is electrically connected to each other by the conductive adhesive layer 301 and is also electrically connected to each other by the interconnector 2 through the conductive adhesive layer 301.

The conductive adhesive layer 301 can be formed by applying a conductive adhesive using a silk screen or moving a syringe while discharging the conductive adhesive at a constant discharge amount.

As shown in FIGS. 5C and 5D, the solar battery cell 103 constituting the solar battery module according to the fourth embodiment of the present invention is between the finger electrodes 1 on the surface and on the finger electrodes 1. The conductive adhesive layer 302 is formed discontinuously in a dot shape along the position where the interconnector 2 is disposed, and then the interconnector 2 is pasted.

The interconnector 2 comes into contact with the finger electrode 1 by being pressed toward the surface of the solar battery cell 103 at the time of pasting. At this time, the conductive adhesive 302 on the finger electrode 1 flows on both sides of the finger electrode 1.

The dot-like conductive adhesive layer 302 can be formed by discharging the conductive adhesive from the syringe at each position while moving the syringe intermittently with respect to the solar battery cell 103.

The interconnector 2 is attached to the surface of the solar battery cell 103 by the conductive adhesive layer 302. The plurality of finger electrodes 1 are electrically connected to each other by the conductive adhesive layer 302 and the interconnector 2 that are in contact with both sides.

As shown in FIGS. 5E and 5F, the solar battery cell 104 constituting the solar battery module according to the fifth embodiment of the present invention has a plurality of finger electrodes 1 on the surface in the same manner as the solar battery cell 102. None of them has a pad portion. The solar battery cell 104 discontinuously forms the conductive adhesive 302 in the form of dots along the position of the interconnector 2 between the finger electrodes 1 on the surface and on the finger electrode 1. It is affixed and configured.

The interconnector 2 is affixed to the surface of the solar battery cell 104 without contacting the finger electrode 1 with the conductive adhesive 302. The plurality of finger electrodes 1 are electrically connected by the interconnector 2 via the conductive adhesive 302.

As shown in FIGS. 5G and 5H, a solar battery cell 105 constituting a solar battery module according to the sixth embodiment of the present invention has a plurality of finger electrodes 1 on the surface in the same manner as the solar battery cell 102. None of them has a pad portion. The solar battery 105 is formed by discontinuously forming the conductive adhesive layer 302 in a dot shape between the finger electrodes 1 on the surface so that one of them is in contact with the finger electrode 1 along the position of the interconnector 2. The interconnector 2 is pasted.

The interconnector 2 is attached to the surface of the solar battery cell 105 without contacting the finger electrode 1 by the conductive adhesive layer 302. The plurality of finger electrodes 1 are electrically connected by the interconnector 2 via the conductive adhesive layer 302.

As shown in FIGS. 5I and 5J, the solar battery cell 106 constituting the solar battery module according to the seventh embodiment of the present invention has a plurality of finger electrodes 1 on the surface in the same manner as the solar battery cell 102. None of them has a pad portion. After the solar battery cells 106 are formed on the surface between the finger electrodes 1 and on the finger electrodes 1, the conductive adhesive layers 302 are partially overlapped with each other in the form of dots along the arrangement position of the interconnector 2. The interconnector 2 is pasted.

The interconnector 2 is attached to the surface of the solar battery cell 106 without contacting the finger electrode 1 by the conductive adhesive layer 302. The plurality of finger electrodes 1 are electrically connected by the conductive adhesive layer 302 and also electrically connected by the interconnector 2 through the conductive adhesive layer 302.

As shown in FIGS. 5K and 5L, the solar battery cell 107 constituting the solar battery module according to the eighth embodiment of the present invention has a plurality of finger electrodes 1 on the surface in the same manner as the solar battery cell 102. None of them has a pad portion. The solar battery 107 has a conductive adhesive located between the finger electrodes 1 on the surface so that a plurality of conductive adhesive layers 302 overlap each other in a dot shape along the position where the interconnector 2 is disposed, and at both ends. After the outer side of the agent layer 302 is formed so as to be in contact with the finger electrode 1, the interconnector 2 is pasted.

The interconnector 2 is affixed to the surface of the solar cell 107 without contacting the finger electrode 1 by the conductive adhesive layer 302. The plurality of finger electrodes 1 are electrically connected by the conductive adhesive layer 302 and also electrically connected by the interconnector 2 through the conductive adhesive layer 302.

5A to 5L, it is possible to maintain a robust fixing state of the interconnector 2 on the surfaces of the solar cells 102 to 107 and to secure an electrical connection state of the plurality of finger electrodes 1. In addition, the coating amount can be reduced as compared with the case where the conductive adhesive is applied over the entire length of the range in which the interconnector 2 is disposed.

Note that the configuration shown in FIGS. 5A to 5L can be similarly applied to a solar cell including the finger electrode 1 having a pad portion.

As shown in FIG. 6A, when a plurality of dot-like conductive adhesive layers 302 are formed by overlapping a part of each other, the conductive adhesive layer 302 is entirely before the interconnector 2 is applied. The first width W1 and the second width W2 are included.

The conductive adhesive layer 302 is used to attach the interconnector 2 to the surface of the solar battery cell 10. Therefore, when the first width W1 which is the maximum width of the conductive adhesive layer 302 is larger than the constant width WA of the interconnector 2, the portion exceeding the constant width WA does not contact the interconnector 2, and the interconnector 2 It does not fulfill the function of attaching 2 to the surface of the solar battery cell 10. For this reason, it is desirable that the first width W1 be equal to or smaller than the constant width WA.

Further, if the first width W1 is less than 50% of the constant width WA, the contact area with the interconnector 2 becomes too small, and the interconnector 2 can be firmly attached to the surface of the solar battery cell 10. Since it is not possible, it is desirable to set it to 50% or more of the constant width WA.

On the other hand, when the second width W2 exceeds 62% of the first width W1, the area of the overlapping portion SA of the adjacent conductive adhesive layer 302 is larger than the area of the hatched portion SB in FIG. Also grows. In the conductive adhesive layer 302, the overlapping portion SA has twice as much conductive adhesive as the other portions. If the area of the overlapping portion SA is equal to the area of the hatched portion SB, the same amount of the conductive adhesive as in the case where the conductive adhesive layer 302 is uniformly formed with the first width W1 has been applied. become. Therefore, in order to reduce the application amount of the conductive adhesive compared to the case where the first width W1 is uniformly formed, it is desirable that the second width W2 is 60% or less of the first width W1.

As shown in FIG. 6B, when the plurality of dot-like conductive adhesive layers 302 are discontinuously formed apart from each other, the second width W2 becomes 0 and the first width The condition of 60% or less of the width W1 is satisfied. In addition, as shown in FIG. 6C, when the elliptical conductive adhesive layer 301 is formed discontinuously, the second width W2 is 0 and is 60% or less of the first width W1. Satisfy the condition of The same applies to the case where the rectangular conductive adhesive layer 301 is formed discontinuously.

The description of the above-described embodiment is an example in all respects, and should be considered as not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

1-Finger electrode 2-Interconnector 3-Conductive adhesive layer 11-Pad part 31-Conductive adhesive

Claims (4)

A solar cell module comprising a plurality of solar cells,
Each of the plurality of solar cells is
A plurality of finger electrodes formed in parallel to each other with a certain interval between the surfaces in a state protruding from the surface of each solar battery cell,
An interconnector presenting a band shape of a constant width and disposed along a direction orthogonal to the longitudinal direction of the plurality of finger electrodes;
A conductive adhesive layer configured with a conductive adhesive and fixing the interconnector to the surface in a state of being electrically connected to the plurality of finger electrodes;
The conductive adhesive layer is formed in a portion including at least the intervals of the plurality of finger electrodes on the surface and in a range where the interconnector is disposed, and is narrower than the constant width in the longitudinal direction. A portion having a width of 1 and a portion having a second width narrower than the first width.
Solar cell module. The solar cell module according to claim 1, wherein the first width is 50% or more of the fixed width. The solar cell module according to claim 1 or 2, wherein the second width is 60% or less of the first width. 4. The solar cell according to claim 1, wherein the conductive adhesive layer is not continuous in a direction perpendicular to a longitudinal direction of the finger electrode at a portion where each of the plurality of finger electrodes overlaps with the interconnector. 5. module.

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