US20170301811A1

US20170301811A1 - Solar cell bonded to a flexible support

Info

Publication number: US20170301811A1
Application number: US15/642,443
Authority: US
Inventors: Cory Tourino; Benjamin Richards
Original assignee: Solaero Technologies Corp
Current assignee: Solaero Technologies Corp
Priority date: 2014-05-20
Filing date: 2017-07-06
Publication date: 2017-10-19
Also published as: US9728663B1

Abstract

A solar cell assembly in which a solar cell component is bonded to a flexible support is disclosed. The solar cell assembly comprises a flexible support with a predetermined size, a solar cell component, bonding adhesive between the support and the solar cell component, wherein the support with the predetermined size has a uniform borders of 0.003 inch to 0.2 inch in width extending beyond the edges of the solar cell component.

Description

REFERENCE TO RELATED APPLICATIONS

This application is a divisional of co-pending U.S. patent application Ser. No. 14/282,610 filed May 20, 2014.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a solar cell assembly and a method of bonding a solar cell component to a flexible support in order to manufacture the solar cell assembly.

Description of the Related Art

A solar cell assembly can be manufactured by bonding a solar cell component to a support. In the solar cell assembly, bonding adhesive is disposed between the solar cell component and the support, in order to bond the solar cell component to the support. In the prior art, US20120090661A1 discloses individually encapsulated solar cells and solar cell strings, U.S. Pat. No. 8,107,777B2 discloses a polyimide support bonded on other support, and WO2006108314A1 discloses a solar cell module and a method of encapsulating the solar cell module.
A bowing phenomenon often occurs in solar cells, especially in large area solar cells. The bowing phenomenon in solar cells means that the front surfaces and the back surfaces of the solar cells are not ideally flat. Further, the degrees of the bowing phenomenon may differ among solar cells. In other words, some solar cells may have relatively bigger bow as illustrated in FIG. 1A, while some other solar cells may have relatively smaller bow as illustrated in FIG. 1B. It should be understood that FIGS. 1A and 1B are illustrative and do not denote the real size of the solar cells and the real degrees of bowing. The real degrees of bowing of the solar cells are much lower than those as illustrated by FIGS. 1A and 1B.
Above bowing phenomenon causes the following problem. Specifically, a relatively bigger bow renders a relatively bigger space between a solar cell and a support, and a relatively smaller bow renders a relatively smaller space between a solar cell and a support. When bonding adhesive is disposed between the solar cell and the support in order to bond them together, a relatively larger amount of bonding adhesive can reside in the relatively bigger space between the solar cell with a relatively bigger bow and the support as illustrated in FIG. 1A. However, when bonding adhesive is disposed between the solar cell and the support in order to bond them together, a relatively smaller amount of bonding adhesive can reside in the relatively smaller space between the solar cell with a relatively smaller bow and the support as illustrate in FIG. 1B. In this case, excessive amount of bonding adhesive may flows to the edges. The excessive amount of bonding adhesive flowing to the edges may further flow away from the edges and contaminate the solar cell and the support, which is unfavourable.
Thus, a method of bonding a solar cell to a support, in which the bonding adhesive is prevented from flowing away from the edges, are needed in the art.

SUMMARY

According to an aspect of an embodiment of the present disclosure, there is provided a method of bonding a solar cell component to a support, the method comprising: (a) Cutting the support to a predetermined size, (b) Dispensing bonding adhesive on top of the support or on back of the solar cell component, (c) Laying down the solar cell component onto the support, wherein the support is flexible and the support has uniform borders of 0.003 inch to 0.2 inch in width extending beyond the edges of the solar cell component.
According to an implementation, the method may further comprise: weighting the solar cell component after laying down the solar cell component onto the support.
According to another aspect of an embodiment of the present disclosure, there is provided a solar cell assembly, comprising: a flexible support with a predetermined size, a solar cell component, bonding adhesive bonding the support and the solar cell component, wherein the support with the predetermined size has uniform borders of 0.003 inch to 0.2 inch in width extending beyond the edges of the solar cell component.
Further aspects, features and advantages of the present invention will be understood from the following description with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

FIG. 1A is a simplified view schematically illustrating a case of solar cell having a relatively bigger bow.

FIG. 1B is a simplified view schematically illustrating a case of solar cell having a relatively smaller bow.

FIG. 2 illustrates a preferable embodiment of the method of bonding a solar cell component to a flexible support according to this invention.

FIG. 3 is a simplified view schematically illustrating a possible pattern of the bonding adhesive dispensed on top of the support or on back of the solar cell component.

FIGS. 4A, 4B and 4C schematically illustrate the configuration of the solar cell assembly obtained by the preferable method of this invention.

FIG. 5 schematically illustrates a further preferable embodiment of the method of bonding a solar cell component to a flexible support according to this invention.

FIGS. 6A, 6B and 6C are simplified views schematically illustrating the configurations of the solar cell assemblies obtained by the further preferable method.

DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present disclosure will be described in detail below with reference to the drawings. Note that similar reference numerals are used to refer to similar elements throughout the drawings, and thus repetitive descriptions thereof are omitted.
FIG. 1A is a simplified view schematically illustrating a case of solar cell having a relatively bigger bow. FIG. 1B is a simplified view schematically illustrating a case of solar cell having a relatively smaller bow. FIG. 2 schematically illustrates a preferable embodiment of the method of bonding a solar cell component to a flexible support according to this invention.
An insulating flexible support is prepared in advance. The insulating flexible support can be made of a flexible material. For example, it can be made of a polyester, polyamide or polyimide material. It is preferable that the insulating flexible support is made as a continuous strip or sheet.
A solar cell component is also prepared in advance. The solar cell component can be in form of an individual solar cell, a coverglass-interconnect-cell (CIC) assembly, a string of solar cells or a string of CICs. In a string of solar cells or a string of CICs, it is preferable that the solar cells or CICs are attached and connected together by welding, soldering, wire boding, conductive paste or the like.
The method of bonding a solar cell component to a flexible support according to this application will be described with reference to FIG. 2.
In step S201, the flexible support is cut to a predetermined size. According to a preferable embodiment of this invention, the flexible support is cut, so that support with the predetermined size has uniform borders of 0.003 inch to 0.2 inch in width extending beyond the edges of the solar cell component. The particularly designed uniform borders of 0.003 inch to 0.2 inch in width extending beyond the edges of the solar cell component are advantage over the prior art. Specifically, the uniform borders are particularly designed, because it is found by the inventors that such designed uniform borders enable the fluid bonding adhesive to wick and stay adjacent the edges of the solar cell by surface tension. That is, the particularly designed uniform borders of 0.003 inch to 0.2 inch in width help to prevent the fluid bonding adhesive from flowing away from the edges.
In step S202, the bonding adhesive is dispensed. The bonding adhesive can be dispensed on top of the support or on back of the solar cell component. The bonding adhesive can be dispensed in a pattern. For example, the bonding adhesive can be dispensed on the solar cells 300 in a pattern 301 as illustrated in FIG. 3. However, the pattern 301 of the bonding adhesive is not limited, as long as the solar cells can be bonded to the flexible support. Instead of dispensing the bonding adhesive on back of the solar cells 300 as illustrated in FIG. 3, the bonding adhesive can also be dispensed on top of a support. It is preferable that the bonding adhesive's viscosity ranges between 1000 millipascal-second and 50000 millipascal-second.
In step S203, the solar cell component is laid down onto the support. The solar cell component is aligned with the support, in order to leave uniform borders of 0.003 inch to 0.2 inch in width of the support extending beyond the edges of the solar cell component. It is more preferable to make the border width range between 0.003 inch to 0.1 inch, 0.003 inch to 0.05 inch, 0.005 inch to 0.025 inch or even 0.010 inch to 0.025 inch.
The solar cell component is bonded with the flexible support with the bonding adhesive. If a solar cell is bowing, the flexible support conforms to the bow of the solar cell. Accordingly, the bonding adhesive has roughly uniform thickness under a solar cell. A part of bonding adhesive flows to the borders of the flexible support. Since the flexible support conforms to the bow of the solar cell, the space between the solar cell and the support does not vary significantly between the case of a relatively bigger bow and the case of a relatively small bow. Accordingly, the amount of bonding adhesive flew to the border does not vary significantly between the case of a relatively bigger bow and the case of a relatively small bow. Because of the particularly designed uniform borders of 0.003 inch to 0.2 inch in width extending beyond the edges of the solar cell component, the fluid bonding adhesive wicks and stays adjacent the edges of the solar cell by surface tension. Accordingly, the particularly designed uniform borders of 0.003 inch to 0.2 inch in width help to prevent the fluid bonding adhesive from flowing away from the edges.
After the step of S203, another optional step S204 can also be performed. In step S204, the solar cell is weighted to facilitate the flowing of the bonding adhesive.
FIGS. 4A, 4B and 4C schematically illustrate the configuration of the solar cell assembly obtained by above preferable method. FIG. 4A illustrates a case that a solar cell is not bowing. FIG. 4B illustrates the case that a solar cell has a relatively bigger bow. FIG. 4C illustrates the case that a solar cell has a relatively smaller bow. Although the solar cell component is illustrated as one solar cell in FIGS. 4A, 4B and 4C, it should be understood that the solar cell component can be in various forms. For example, the solar cell component can be a coverglass-interconnect-cell (CIC) assembly, a string of solar cells or a string of CICs, instead of one solar cell. Although not illustrated, each solar cell component may include multiple mechanical standoffs on its back side. For example, the multiple mechanical standoffs are interconnects or shims.
In each of FIGS. 4A, 4B and 4C, the bonding adhesive between the solar cell component and the support has a rough uniform thickness. The flexible supports conform to the bows of the solar cells, regardless of the degrees of bowing of the solar cells.
In all cases as illustrated by FIGS. 4A, 4B and 4C, the flexible support have uniform borders extending beyond the solar cells of 0.003 inch to 0.2 inch in width. A part of the bonding adhesive flows to the border of the support extending beyond the solar cell. This part of bonding adhesive wicks and stay adjacent the edges of the solar cell by surface tension, instead of flowing away from the edges.
FIG. 5 schematically illustrates a further preferable embodiment of the method of bonding a solar cell component to a flexible support according to this invention.
This embodiment illustrated in FIG. 5 is similar to that as illustrated in FIG. 2, except that the bonding adhesive includes rigid particles of uniform size. It is preferable that the rigid particles are spheres or rough spheres. The rigid particles can be made of rigid material, such as glass. The material of the particles is not limited, as long as the particle is rigid.
FIGS. 6A, 6B and 6C are simplified views schematically illustrating the configurations of the solar cell assemblies obtained by the further preferable method.
As illustrated by FIGS. 6A, 6B and 6C, the rigid particles of uniform size function to support the solar cells on the support. Accordingly, the uniform size of the rigid particles further facilitates to ensure a uniform thickness of the bonding adhesive, regardless of the degrees of bowing of the solar cells. As a result, the amount of bonding adhesive flew to the border of the support can be controlled better.
Moreover, the terms “front,” “back,” “top,” “bottom,” “over,” “under” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.
Furthermore, those skilled in the art will recognize that boundaries between the above described operations merely illustrative. The multiple units/operations may be combined into a single unit/operation, a single unit/operation may be distributed in additional units/operations, and units/operations may be operated at least partially overlapping in time. Moreover, alternative embodiments may include multiple instances of a particular unit/operation, and the order of operations may be altered in various other embodiments.
In the claims, the word ‘comprising’ or ‘having’ does not exclude the presence of other elements or steps then those listed in a claim. The terms “a” or “an,” as used herein, are defined as one or more than one. Also, the use of introductory phrases such as “at least one” and “one or more” in the claims should not be construed to imply that the introduction of another claim element by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim element to inventions containing only one such element, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an.” The same holds true for the use of definite articles. Unless stated otherwise, terms such as “first” and “second” are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements. The fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage.
The present invention can be embodied in various ways. The above described orders of the steps for the methods are only intended to be illustrative, and the steps of the methods of the present disclosure are not limited to the above specifically described orders unless otherwise specifically stated. Note that the embodiments of the present disclosure can be freely combined with each other without departing from the spirit and scope of the invention.
Although some specific embodiments of the present invention have been demonstrated in detail with examples, it should be understood by a person skilled in the art that the above examples are only intended to be illustrative but not to limit the scope of the present invention. It should be understood that the above embodiments can be modified without departing from the scope and spirit of the present invention which are to be defined by the attached claims.

Claims

1. A solar cell assembly, comprising:

a flexible support having a top side and a bottom side and a predetermined size;

a flat, non-bowed solar cell component having a top side and a bottom side; and

bonding adhesive located between the top side of the support and the bottom side of the solar cell component;

wherein the support has substantially uniform borders of 0.003 inches to 0.2 inches in width extending beyond the edges of the solar cell component.

2. The solar cell assembly of claim 1, wherein the bonding adhesive comprises rigid particles of substantially uniform size.

3. The solar cell assembly of claim 1, wherein the solar cell component comprises multiple mechanical standoffs that are interconnects or shims on the bottom side of the solar cell component.

4. The solar cell assembly of claim 2, wherein the rigid particles are composed of glass and are spherical or substantially spherical in shape.

5. The solar cell assembly of claim 1, wherein the solar cell component is selected from the group consisting of a solar cell, a coverglass-interconnect-cell (CIC) assembly, a string of solar cells, a string of a coverglass-interconnect cells (CICs), and combinations thereof.

6. The solar cell assembly of claim 1, wherein the border has a width of 0.003 inches and 0.1 inches.

7. The solar cell assembly of claim 1, wherein the border had a width of 0.003 inches to 0.05 inches.

8. The solar cell assembly of claim 1, wherein the border has a width of 0.005 inches to 0.025 inches.

9. The solar cell assembly of claim 1, wherein the border has a width of 0.010 inches to 0.025 inches.