WO2013112845A1

WO2013112845A1 - A photovoltaic cell module and method of forming the same

Info

Publication number: WO2013112845A1
Application number: PCT/US2013/023159
Authority: WO
Inventors: Barry M. KETOLA
Original assignee: Dow Corning Corporation
Priority date: 2012-01-26
Filing date: 2013-01-25
Publication date: 2013-08-01
Also published as: TW201334959A

Abstract

A photovoltaic (PV) cell module comprises a substrate, a cover sheet spaced from the substrate, PV cells disposed between the substrate and the cover sheet, and tabbing ribbon disposed between the PV cells. Polymeric strips formed from a first polymeric composition are disposed between the PV cells and the cover sheet. A tie-layer formed from a second polymeric composition, different than the first polymeric composition, is disposed between the substrate and the cover sheet and between the polymeric strips. The polymeric strips are formed on the cover sheet by applying the first polymeric composition to portions of the cover sheet. The PV cells are then disposed on the polymeric strips. The second polymeric composition is applied over the cover sheet between the polymeric strips and over the PV cells to form the tie-layer. The substrate and the cover sheet are then combined to form the module.

Description

A PHOTOVOLTAIC CELL MODULE AND METHOD OF FORMING THE SAME

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 61/590,996, filed on January 26th, 2012, which is incorporated herewith by reference in its entirety.

BACKGROUND

[0002] The present invention generally relates to a photovoltaic (PV) cell module and to a method of forming the PV cell module.

[0003] Solar or PV cells are semiconductor devices used to convert light into electricity. In many applications, the PV cells are encapsulated to form PV cell modules. The modules typically include a cover sheet (or "superstrate") and a back sheet (or "substrate"), such that the PV cells and encapsulant are sandwiched between the cover sheet and substrate. The PV cells are operatively connected to one another with tabbing ribbon. The encapsulant and cover sheet protect the PV cells from environmental factors, such as wind, dirt, and rain. A common encapsulant is ethyl vinyl acetate (EVA) and another is silicone. EVA has one or more drawbacks, such as low UV resistance, degradation over time, discoloration over time, etc. As such, silicone has been used in certain applications to replace EVA in modules. A single type of silicone can be used to completely encapsulate the PV cells within the module. Alternatively, a layer of a first silicone is used between the PV cells and the cover sheet and a layer of a second silicone is used between the PV cells and the substrate. The first silicone is typically softer than the second silicone, which is useful during manufacture of the modules, e.g. to prevent damage to the PV cells during pressing. Specifically, if the first silicone is too hard, the cells can crack or the silicone will not deform properly allowing for trapped air bubbles, which is undesirable. The second silicone is useful for maintaining position of the PV cells during thermal expansion and contraction of the encapsulant. Specifically, the second silicone is typically harder than the first silicone, and is less prone to thermal expansion and contraction upon heating and cooling of the module.

[0004] Unfortunately, the layer of the first silicone can still allow for the PV cells to move during thermal expansion and contraction, which can lead to PV cell cracking and/or the tabbing ribbon breaking or degrading. For example, the first silicone can expand and contract to a greater extent than the second silicone, such that at their interface, the tabbing ribbon can bend and break since one end of the tabbing ribbon is being held back by the second silicone and the other end of the tabbing ribbon is being moved by the first silicone. These issues can lead to power degradation or even complete failure of the module. Modules employing just the single type of silicone can suffer from the same problems, where the PV cells move too much during expansion and contraction, which can lead to degradation/breakage of the tabbing ribbon. Accordingly, there remains an opportunity to provide improved modules with excellent durability, such as improved resistance to PV cell cracking and reduced power degradation after thermal cycling. There also remains an opportunity to provide improved methods of forming modules that can provide excellent production efficiency, cost savings, and repeatability.

SUMMARY OF THE INVENTION

[0005] The present invention provides a photovoltaic (PV) cell module. The invention module comprises a substrate having a front face and a rear face spaced from the front face of the substrate. The module also comprises a cover sheet having a front face and a rear face spaced from the front face of the cover sheet. A first PV cell is disposed between the substrate and the cover sheet. The first PV cell has a front face and a rear face spaced from the front face of the first PV cell. A second PV cell is disposed between the substrate and the cover sheet and disposed adjacent the first PV cell. The second PV cell has a front face and a rear face spaced from the front face of the second PV cell. A tabbing ribbon is disposed between the PV cells. The tabbing ribbon has a first end operatively connected to the front face of the first PV cell and a second end operatively connected to the rear face of the second PV cell. A first polymeric strip formed from a first polymeric composition is disposed between the first PV cell and the cover sheet for coupling the front face of the first PV cell to the rear face of the cover sheet. A second polymeric strip also formed from the first polymeric composition is disposed between the second PV cell and the cover sheet for coupling the front face of the second PV cell to the rear face of the cover sheet. A tie-layer formed from a second polymeric composition, different than the first polymeric composition, is disposed between the substrate and the cover sheet and between the polymeric strips for coupling the rear face of the cover sheet to the front face of the substrate and for coupling the rear faces of the PV cells to the front face of the substrate.

[0006] The present invention also provides a method of forming the invention module. The invention method comprises the step of applying the first polymeric composition to first and second portions of the rear face of the cover sheet to form the first and second polymeric strips in an uncured state. The method further comprises the step of disposing the first and second PV cells on the first and second polymeric strips. The tabbing ribbon operatively connects the first and second PV cells. The method further comprises the step of applying the second polymeric composition over the rear face of the cover sheet between the polymeric strips and over the PV cells and over the tabbing ribbon to form the tie-layer in an uncured state. The method further comprises the step of combining the substrate and the cover sheet to form the module. The module may be used for various applications, such as for converting light of many different wavelengths into electricity.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present invention may be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

[0008] FIG. 1 is perspective view of a pair of photovoltaic (PV) arrays each including an embodiment of PV cell modules;

[0009] FIG. 2 is a broken exploded cross-sectional side-view of an embodiment of the PV cell module including PV cells;

[0010] FIG. 3 is a broken cross-sectional side-view of the embodiment of the PV cell module including PV cells;

[0011] FIG. 4 is a broken cross-sectional front-view of the PV cell module of FIG. 3 taken along line 4-4;

[0012] FIG. 5 is a broken cross-sectional schematic side-view illustrating a first polymeric composition being applied to a cover sheet to form polymeric strips;

[0013] FIG. 6 is broken a cross-sectional schematic side-view illustrating PV cells being disposed over the polymeric strips;

[0014] FIG. 7 is a broken cross-sectional schematic side-view illustrating a second polymeric composition being applied over the PV cells and the cover sheet to form a tie- layer;

[0015] FIG. 8 is a broken cross-sectional schematic side-view illustrating a substrate and the cover sheet being combined to form an embodiment of the PV cell module; and

[0016] FIG. 9 is a broken cross-sectional side-view of another embodiment of the PV cell module including PV cells.

DETAILED DESCRIPTION OF THE INVENTION

[0017] Referring to the Figures (FIGs.), wherein like numerals indicate like parts throughout the several views, a photovoltaic (PV) cell module formed in accordance with the invention method is shown generally at 20. The PV cell module 20 is hereinafter referred to as the module 20. The components of the invention module 20 are not necessarily drawn to scale in the figures, such that they may be larger or smaller than that which is depicted.

[0018] Referring to FIG. 1 , a plurality of modules 20 is connected to form a pair of arrays 22. The arrays 22 may be planar or non-planar. While shown in this configuration/arrangement, the module 20 may be used alone or in a group of two or more (e.g., as shown in FIG. 1 ), and may be used for various applications, such as for structures, buildings, vehicles, devices, etc. The present invention is not limited to any particular configuration or use of the modules 20 or arrays 22. The modules 20 can be used to convert light energy into electrical energy.

[0019] Referring to FIG. 2, the module 20 comprises a substrate 24. The substrate 24 has a front face 26 and a rear face 28 spaced from the front face 26. The substrate 24 may be substantially planar or non-planar. The substrate 24 may also be referred to in the art as a backsheet 24. The substrate 24 is useful for providing support, protection, and/or an interface for the module 20.

[0020] The substrate 24 can be formed from various materials. Examples of suitable materials include glass, polymeric materials, composite materials, etc. For example, the substrate 24 can be formed from glass, polyethylene terephthalate (PET), thermoplastic elastomer (TPE), polyvinyl fluoride (PVF), silicone, etc. The substrate 24 may be formed from a combination of different materials, e.g. a polymeric material and a fibrous material. The substrate 24 may have portions formed from one material, e.g. glass, and other portions formed from another material, e.g. a polymeric material. The substrate 24 can be of various thicknesses, such as from about 0.05 to about 5, about 0.1 to about 4, or about 0.125 to about 3.2, millimeters (mm) on average, or any range between the lowest and highest of these values. Thickness of the substrate 24 may be uniform or may vary.

[0021] Further examples of suitable substrates 24 include those described in U.S. App. Pub. Nos. 2008/0276983, 201 1/0005066, and 201 1/0061724, and in WO Pub. Nos. 2010/051355 and 2010/141697. Yet further examples of suitable substrates 24 include those described as "backsheets" in U.S. Pat. App. Ser. No. 61 /725277 ("the '277 application"; Attorney Docket No. DC1 1521 PSP1 ; 071038.01095). The aforementioned disclosures are hereinafter referred to as the "incorporated references", which are incorporated herein by reference in their entirety to the extent they do not conflict with the general scope of the present invention. If any conflict exists between the instant disclosure and any of the incorporated reference(s), only the portion(s) of any of the incorporated reference(s) that are in conflict with the instant disclosure, rather than an entirety of any of the incorporated reference(s), are expunged from incorporation herein from the incorporated reference(s).

[0022] The module 20 further comprises a cover sheet 30. The cover sheet 30 has a front face 32 and a rear face 34 spaced from the front face 32. The cover sheet 30 may be substantially planar or non-planar. The cover sheet 30 is useful for protecting the module 20 from environmental conditions such as rain, snow, dirt, heat, etc. Typically, the cover sheet 30 is transparent to UV and/or visible light as understood in the art for gathering light energy. Said another way, the cover sheet 30 is typically optically transparent. The cover sheet 30 is generally the sun side or front side of the module 20.

[0023] The cover sheet 30 can be formed from various materials understood in the art. Examples of suitable materials include those described above with description of the substrate 24. Further examples of suitable cover sheets 30 include those described in the incorporated references. In certain embodiments, the cover sheet 30 is formed from glass. Various types of glass can be utilized such as silica glass, polymeric glass, etc. The cover sheet 30 may be formed from a combination of different materials. The cover sheet 30 may have portions formed from one material, e.g. glass, and other portions formed from another material, e.g. a polymeric material. The cover sheet 30 may be the same as or different from the substrate 24. For example, both the cover sheet 30 and the substrate 24 may be formed from glass with equal or differing thicknesses.

[0024] The cover sheet 30 can be of various thicknesses, such as from about 0.5 to about 10, about 1 to about 7.5, about 2.5 to about 5, or about 3, mm on average, or any range between the lowest and highest of these values. Thickness of the cover sheet 30 may be uniform or may vary. Further examples of suitable cover sheets 30 include those described in the incorporated references, such as those described as the "superstrates" in the '277 application.

[0025] The module 20 further comprises a first PV cell 36 and a second PV cell 38. The PV cells 36, 38 are disposed between the substrate 24 and the cover sheet 30. As best shown in FIGs. 2-4, the second PV cell 38 is adjacent the first PV cell 36. The first PV cell 36 has a front face 40 and a rear face 42 spaced from the front face 40. The second PV cell 38 also has a front face 44 and a rear face 46 spaced from the front face 44.

[0026] As best shown in FIG. 3, the PV cells 36, 38 are substantially coplanar with one another. As shown in FIGs. 3 and 4, the module 20 can include more than just the pair of PV cells 36, 38. The PV cells 36, 38 can be arranged in various patterns, such as a series of PV cells 36, 38 in a grid-like pattern. The PV cells 36, 38 may be offset from one another, such as in non-planar module 20 configurations.

[0027] The PV cells 36, 38 may be of various dimensions, be of various types, and be formed from various materials. Examples of suitable PV cells 36, 38 include those described in the incorporated references. The first PV cell 36 may be the same as or different from the second PV cell 38. The PV cells 36, 38 can be of various thicknesses, such as from about 50 to about 250, about 100 to about 225, about 175 to about 225, or about 180, μηι on average, or any range between the lowest and highest of these values. The PV cells 36, 38 can also be of various widths and lengths as understood in the art. In certain embodiments, the PV cells 36, 38 may be referred to in the art as crystalline silicon PV cells 36, 38. Further examples of suitable PV cells 36, 38 include those described in the incorporated references, such as those described in the '277 application.

[0028] As best shown in FIG. 2, a tabbing ribbon 48 is disposed between the PV cells 36, 38. A series of two or more connected PV cells 36, 38 may be referred to in the art as a string of cells. The tabbing ribbon 48 has a first end 50 operatively connected to the front face 40 of the first PV cell 36 and a second end 52 operatively connected to the rear face 46 of the second PV cell 38. As best shown in FIG. 4, a pair of tabbing ribbons 48 is connected between the PV cells 36, 38, with the tabbing ribbons 48 spaced from one another. The tabbing ribbon 48 is useful for establishing a circuit in the module 20. The ends 50, 52 of the tabbing ribbon 48 typically extend over the faces 40, 42, 44, 46 of the PV cells 36, 38 as shown in FIG. 2; however, they may also be longer or shorter than as depicted in the Figures.

[0029] The tabbing ribbon 48 may be formed from various conductive materials, such as metals, conducting polymers, or combinations thereof. Examples of other suitable materials include those described in the incorporated references. The tabbing ribbon 48 is useful for connecting the PV cells 36, 38 together, as well as to other components such as to bussing (not shown), other modules 20, etc. The PV cells 36, 38 may be connected by the tabbing ribbon 48 in series or in parallel. The tabbing ribbons 48 are typically connected to bussing (not shown) for establishing a circuit and carrying energy collected by the PV cells 36, 38.

[0030] While called tabbing "ribbon" 48, the tabbing ribbon 48 may be of various shapes and sizes, and may also be referred to in the art as tabbing, bussing, wire, or leads, depending on shape, size, location, etc. The tabbing ribbon 48 can be of various dimensions, such as from about 0.125 to about 2 mm in thickness and/or width on average.

[0031] As best shown in FIG. 3, a first polymeric strip 54 is disposed between the first PV cell 36 and the cover sheet 30 for coupling the front face 40 of the first PV cell 36 to the rear face 34 of the cover sheet 30. As used herein, "coupling" generally means physically connecting, unless indicated otherwise. The first polymeric strip 54 is formed from a first polymeric composition.

[0032] The first polymeric composition may be formed from various polymer compositions. Typically, the first polymeric composition is a silicone, more typically a silicone elastomer. Suitable silicones include branched and unbranched, more typically unbranched, oligomeric or polymeric organosiloxanes. Examples of suitable polymeric compositions include hydrosilylation-reaction, condensation-reaction, and hydrosilylation/condensation- reaction, curable silicone compositions.

[0033] In certain embodiments, the first polymeric strip 54 is formed from a hydrosilylation- reaction curable silicone composition. In further embodiments, the first polymeric composition comprises a diorganopolysiloxane having alkenyl groups (e.g. vinyl groups), an organosilicon hydride having silicon-bonded hydrogen atoms reactive with the alkenyl groups of the diorganopolysiloxane, and a non-reactive organopolysiloxane. By "non- reactive", it is generally meant that the non-reactive organopolysiloxane does not react with the diorganopolysiloxane or the organosilicon hydride. Examples of suitable diorganopolysiloxanes, organosilicon hydrides, and non-reactive organopolysiloxanes, include those described in the incorporated references.

[0034] The diorganopolysiloxane and the organosilicon hydride will generally react in the presence of the non-reactive organopolysiloxane, and optionally, additional components, to form a silicone polymer. The non-reactive organopolysiloxane is useful for adjusting physical properties of the silicone polymer as described further below. Examples of suitable additive components, such as catalysts, include those described in the incorporated references.

[0035] In certain embodiments, the diorganopolysiloxane is a dimethylvinyl-terminated dimethyl siloxane, the organosilicon hydride is a hydrogen-terminated dimethyl siloxane, and the non-reactive organopolysiloxane is a polydimethylsiloxane (PDMS).

[0036] In a specific embodiment, the first polymeric composition includes, consists essentially of, or consists of: two different dimethylvinyl-terminated polydimethylsiloxanes; a dimethylhydrogen-terminated polydimethylsiloxane; and a trimethylsiloxy-terminated dimethyl methylhydrogen siloxane containing at least 3 SiH units per molecule. Said another way, the first polymeric strip 54 can be the reaction product of these components. The reaction can be catalyzed by a hydrosilylation catalyst, e.g. a platinum-ligand complex, which can be included in, or added to, the first polymeric composition. In this embodiment, the reaction typically occurs in the presence of a PDMS, which can also be included in, or added to, the first polymeric composition. If utilized, the PDMS is non-reactive, e.g. non- reactive toward the aforementioned reactants of the first polymeric composition. As alluded to above, inclusion of components, such as PDMS, is useful for adjusting physical properties of the reaction product.

[0037] In the aforementioned embodiments, the components of the first polymeric composition may be included in various amounts. Typically, the first polymeric composition includes greater than about 45, greater than about 50, greater than about 55, greater than about 60, or greater than about 65, parts by weight of the diorganopolysiloxane, each based on 100 parts by weight of the first polymeric composition, or any range between the lowest and highest of these values. Typically, the first polymeric composition includes from about 2.5 to about 7.5, about 3 to about 7, or about 3.5 to about 6.5, parts by weight of the organosilicon hydride, each based on 100 parts by weight of the first polymeric composition, or any range between the lowest and highest of these values. Typically, the first polymeric composition has from about 25 to about 65, or from about 30 to about 60, parts by weight of the non-reactive organopolysiloxane, each based on 100 parts by weight of the first polymeric composition, or any range between the lowest and highest of these values.

[0038] The first polymeric composition may also be referred to in the art as an encapsulant composition. Specific examples of suitable encapsulant compositions suitable for use as the first polymeric composition are commercially available from Dow Corning Corporation of Midland, Ml, such as Dow Corning® PV-6100 Cell Encapsulant. Further examples of suitable encapsulant compositions include those described in the incorporated references, such as those described as the "silicone encapsulant" in the '277 application.

[0039] As best shown in FIG. 3, a second polymeric strip 56 is disposed between the second PV cell 38 and the cover sheet 30 for coupling the front face 44 of the second PV cell 38 to the rear face 34 of the cover sheet 30. As shown generally, the polymeric strips 54, 56 are spaced horizontally and side-by-side. Further, the polymeric strips 54, 56 are generally disposed perpendicular relative to the direction of the tabbing ribbon 48. Typically, the second polymeric strip 56 is also formed from the first polymeric composition. As such, both of the polymeric strips 54, 56 can be formed from the first polymeric composition as described above. As alluded to above, there may be slight differences between the polymeric strips 54, 56, such as cure rates.

[0040] Each of the polymeric strips 54, 56 can be of various thicknesses, such as from about 0.125 to about 0.75, about 0.2 to about 0.5, or about 0.25 to about 0.45, mm on average, or any range between the lowest and highest of these values. Typically, the thickness of the polymeric strips 54, 56 is varied to minimize the amount of the first polymeric composition that is used, thereby reducing production costs of the module 20, and also to simultaneously minimize or prevent bottoming out of the PV cells 36, 38 and/or the tabbing ribbon 48.

[0041] In this context, "bottoming out" refers to a situation where the PV cells 36, 38 and/or the tabbing ribbon 48 would contact the cover sheet 30, which could cause damage. Such a situation can arise during manufacture and/or use of the module 20. This situation is undesirable. As such, the polymeric strips 54, 56 are useful for cushioning and protecting the PV cells 36, 38 and the tabbing ribbon 48 from the cover sheet 30 in situations where they could potential come into contact with one another.

[0042] Typically, each of the polymeric strips 54, 56 are sandwiched between each of the PV cells 36, 38, as best illustrated in FIG. 3; however, there may be at least one intervening layer (not shown) between the polymeric strips 54, 56 and the cover sheet 30 and/or between the polymeric strips 54, 56 and the PV cells 36, 38. Each of the polymeric strips 54, 56 can be of various widths, such as from about 0.5 to about 25, about 1 .25 to about 13, or about 2.5 to about 6.4, mm on average, or any range between the lowest and highest of these values. Width of the polymeric strips 54, 56 may be uniform or may vary.

[0043] As best shown in FIG. 4, each of the polymeric strips 54, 56 has a width less than the width of the PV cells 36, 38. The polymeric strips 54, 56 may have a width equal to or greater than the width of the PV cells 36, 38.

[0044] As shown in FIG. 3, each of the polymeric strips 54, 56 has a substantially rectangular-shaped cross-section. While the edges of the polymeric strips 54, 56 are illustrated as being convex, the edges may be straight, concave, or a combination of shapes.

[0045] As best shown in FIG. 4, the polymeric strips 54, 56 are disposed transverse relative to the tabbing ribbon 48. Typically, the polymeric strips 54, 56 extend laterally across the module 20 to a periphery of the module 20 on ends of the module 20. Generally, there is at least one polymeric strip 54, 56 for each one of the PV cells 36, 38. There may be two or more narrower polymeric strips 54, 56 for each one of the PV cells 36, 38.

[0046] As best shown in FIG. 3, a tie-layer 58 is disposed between the substrate 24 and the cover sheet 30 and between the polymeric strips 54, 56. The tie-layer 58 is useful for coupling the rear face 34 of the cover sheet 30 to the front face 26 of the substrate 24 and for coupling the rear faces 42, 46 of the PV cells 36, 38 to the front face 26 of the substrate 24. The tie-layer 58 may also be referred to in the art as a polymeric tie-layer 58.

[0047] The tie-layer 58 is formed from a second polymeric composition. The second polymeric composition of the tie-layer 58 is different from the first polymeric composition of the polymeric strips 54, 56. The first and second polymeric compositions can be different in various ways, such as being chemically and/or physically different. Typically, the first and second polymeric compositions are different in such a way to provide different moduli of elasticity. Examples of differences are described below.

[0048] The second polymeric composition may be formed from various polymer compositions. Typically, the second polymeric composition is a silicone, more typically a silicone elastomer. Examples of suitable polymeric compositions include hydrosilylation- reaction, condensation-reaction, and hydrosilylation/condensation-reaction, curable silicone compositions.

[0049] In certain embodiments, the tie-layer 58 is formed from a hydrosilylation-reaction curable silicone composition. In further embodiments, the second polymeric composition comprises a diorganopolysiloxane having alkenyl groups (e.g. vinyl groups), and an organosilicon hydride having silicon-bonded hydrogen atoms reactive with the alkenyl groups of the diorganopolysiloxane. Examples of suitable diorganopolysiloxanes, organosilicon hydrides, and non-reactive organopolysiloxanes include those described in the incorporated references.

[0050] The diorganopolysiloxane and the organosilicon hydride will generally react, optionally, in the presence of additional components, to form a silicone polymer. Examples of suitable additive components, such as catalysts, include those described in the incorporated references.

[0051] In certain embodiments, the diorganopolysiloxane is a dimethylvinyl-terminated dimethyl siloxane, and the organosilicon hydride is a hydrogen -terminated dimethyl siloxane. As introduced above, the second polymeric composition is different than the first polymeric composition. An example of a difference between the first and second polymer compositions is the inclusion of the non-reactive organopolysiloxane in the first polymeric composition while the second polymeric composition excludes the non-reactive organopolysiloxane.

[0052] In a specific embodiment, the second polymeric composition includes, consists essentially of, or consists of: a dimethylvinyl-terminated polydimethylsiloxane; a dimethylhydrogen-terminated polydimethylsiloxane; and a trimethylsiloxy-terminated dimethyl methylhydrogen siloxane containing at least 3 SiH units per molecule. Said another way, the tie-layer 58 can be the reaction product of these components. The reaction can be catalyzed by a hydrosilylation catalyst, e.g. a platinum-ligand complex, which can be included in, or added to, the second polymeric composition.

[0053] In the aforementioned embodiments, the components of the second polymeric composition may be included in various amounts. Typically, the second polymeric composition includes greater than about 55, greater than about 60, or greater than about 65, parts by weight of the diorganopolysiloxane, each based on 100 parts by weight of the second polymeric composition, or any range between the lowest and highest of these values. Typically, the second polymeric composition includes from about 5 to about 25, about 5 to about 20, or about 8 to about 22.5, parts by weight of the organosilicon hydride, each based on 100 parts by weight of the second polymeric composition, or any range between the lowest and highest of these values.

[0054] The second polymeric composition may also include additional components, such as silanes or siloxanes. Such components can be included in various amounts. In certain embodiments, the second polymeric composition further comprises an organosilane and/or a dimethyl methylhydrogen siloxane. Such components can be included in various amounts, such as less than about 5 parts by weight, or from about 0.1 to about 2.5 parts by weight, each based on 100 parts by weight of the second polymeric composition, or any range between the lowest and highest of these values.

[0055] In another specific embodiment, the second polymeric composition includes, consists essentially of, or consists of: a dimethylvinyl-terminated polydimethylsiloxane; and a trimethylsiloxy-terminated dimethyl methylhydrogen siloxane containing at least 3 SiH units per molecule. Said another way, the tie-layer 58 can be the reaction product of these components. The reaction can be catalyzed by a hydrosilylation catalyst, e.g. a platinum- ligand complex, which can be included in, or added to, the second polymeric composition.

[0056] In the aforementioned embodiment, the components of the second polymeric composition may be included in various amounts. Typically, the second polymeric composition includes from about 80 to about 99.9, about 90 to about 99.9, or about 95 to about 99.9, parts by weight of a dimethylvinyl-terminated polydimethylsiloxane (e.g. a dimethyl siloxane, dimethylvinylsiloxy-terminated polymer), each based on 100 parts by parts by weight of the second polymeric composition, or any range between the lowest and highest of these values. Typically, the second polymeric composition includes from about 0.01 to about 2, about 0.05 to about 1 , or about 0.05 to about 0.5, parts by weight of a platinum-ligand complex (e.g. 1 ,3-diethenyl-1 ,1 ,3,3-tetramethyldisiloxane complex (Pt)), each based on 100 parts by parts by weight of the second polymeric composition, or any range between the lowest and highest of these values. Typically, the second polymeric composition includes from about 0.01 to about 7.5, about 0.1 to about 5, or about 0.2 to about 2.5, parts by weight of an alkoxysilane (e.g. methacryloxypropyltrimethoxysilane), each based on 100 parts by parts by weight of the second polymeric composition, or any range between the lowest and highest of these values. Typically, the second polymeric composition includes from about 0.05 to about 7.5, about 0.1 to about 5, or about 0.5 to about 2.5, parts by weight of a trimethylsiloxy-terminated dimethyl methylhydrogen siloxane containing at least 3 SiH units per molecule (e.g. dimethyl, methylhydrogen siloxane, trimethylsiloxy-terminated), each based on 100 parts by parts by weight of the second polymeric composition, or any range between the lowest and highest of these values. Typically, the second polymeric composition includes from about 0.001 to about 2.5, about 0.005 to about 1 , or about 0.005 to about 0.5, parts by weight of a siloxane (e.g. tetramethyltetravinylcyclotetrasiloxane), each based on 100 parts by parts by weight of the second polymeric composition, or any range between the lowest and highest of these values.

[0057] The second polymeric composition may also be referred to in the art as an encapsulant composition. Specific examples of suitable encapsulant compositions suitable for use as the second polymeric composition are commercially available from Dow Corning Corporation, such as Dow Corning® PV-6150 Cell Encapsulant. Further examples of suitable encapsulant compositions include those described in the incorporated references, such as those described as the "silicone tie layer" in the '277 application.

[0058] As best shown in FIG. 3, the tabbing ribbon 48 is encapsulated by the tie-layer 58. Encapsulating the tabbing ribbon 48 with the tie-layer 58 is useful for protecting the tabbing ribbon 48. The first end 50 of the tabbing ribbon 48 may be covered by one of the polymeric strips 54, 56 and/or may be covered by the tie-layer 58.

[0059] Without being bound or limited to any particular theory, it is believed that the tie- layer 58 protects the tabbing ribbon 48 during thermocycling of the module 20. For example, as a conventional module heats or cools, the PV cells are prone to move based on thermal expansion and contraction. Over time, the tabbing ribbon is pulled and pinched between the PV cells 36, 38, which will eventually cause the tabbing ribbon to break or degrade. However, relative to conventional modules, the tie-layer 58 substantially maintains orientations of the PV cells 36, 38, and therefore, the tabbing ribbon 48, thus reducing or even preventing the aforementioned issues involving thermocycling of conventional modules. It is believed that the modulus of elasticity of the tie-layer 58 helps to maintain orientation of the PV cells 36, 38 when the module 20 is exposed to changes in temperature, such as during testing or use. Modulus is described below. The PV cells 36, 38 can still move to a certain degree due to thermal fluctuations within the module 20, i.e., they are not generally completely locked into place.

[0060] The tie-layer 58 can be of various thicknesses, such as from about 0.125 to about 1 .25, about 0.2 to about 0.5, or about 0.25 to about 0.4, mm on average, or any range between the lowest and highest of these values. Thickness of the tie-layer 58 is generally defined between the cover sheet 30 and the substrate 24. Thickness can also be defined by the intermediate layer(s), if present. Typically, the thickness of the tie-layer 58 is varied to minimize the amount of the second polymeric composition that is used, thereby reducing production costs of the module 20, and also to simultaneously minimize or prevent bottoming out of the PV cells 36, 38 and/or the tabbing ribbon 48.

[0061] In this context, "bottoming out" refers to a situation where the PV cells 36, 38 and/or the tabbing ribbon 48 would contact the cover sheet 30 and/or the substrate 24 which could cause damage. Such a situation can arise during manufacture and/or use of the module 20. This situation is undesirable. As such, the tie-layer 58 useful for cushioning and protecting the PV cells 36, 38 and the tabbing ribbon 48.

[0062] Typically, the tie-layer 58 is sandwiched between the cover sheet 30 and the substrate 24 as best illustrated in FIG. 3; however, there may be at least one intervening layer (not shown) between the tie-layer 58 and the cover sheet 30 and/or between the tie- layer 58 and the substrate 24. For example, there may be an intervening layer disposed between the tie-layer 58 and the substrate 24. Such an intervening layer is useful for thickness control and strength of the module 20. An example of suitable intervening layer is a nonwoven fiberglass (FG) layer. If included, the intervening layer may also be formed from other materials, such as PET, nylon, or silicone. In certain embodiments (not shown), the module 20 includes a nonwoven FG layer disposed between the substrate 24 and the tie-layer 58.

[0063] Typically, the modulus of elasticity of the tie-layer 58 is greater than the modulus of elasticity of the polymeric strips 54, 56. In other words, the polymeric strips 54, 56 are generally softer than the tie-layer 58. In these embodiments, having different moduli is useful for protecting the PV cells 36, 38 and the tabbing ribbon 48 as described above. The moduli can vary depending on the type of first and second polymeric compositions utilized. In certain embodiments, the shear modulus of elasticity of the tie-layer 58 is from about 15 to about 50, about 17.5 to about 40, or about 20 to about 30, kilopascals (kPa), and the shear modulus of elasticity of the polymeric strips 54, 56 is from about 0.5 to about 12.5, about 1 to about 10, about 1 to about 7.5, about 1 to about 5, or about 1 to about 3, kPa, or any range between the lowest and highest of these values. In other embodiments, the shear modulus of elasticity of the tie-layer 58 is from about 50 to about 2000, about 50 to about 1750, about 50 to about 1500, about 50 to about 1250, about 50 to about 1000, about 50 to about 750, about 75 to about 600, about 100 to about 500, about 150 to about 450, about 200 to about 400, or about 200 to about 300, kPa, and the shear modulus of elasticity of the polymeric strips 54, 56 is as just described, or any range between the lowest and highest of these values. As described above, it is believed that the modulus of elasticity of the tie-layer 58 helps to maintain orientation of the PV cells 36, 38 when the module 20 is exposed to changes in temperature (e.g. during thermo-cycling, expansion/contraction, etc.).

[0064] The module 20 can be of various shapes, sizes, and configurations. In certain embodiments, the module 20 has a length of from about 1 .6 to about 2.0 and a width of from about 0.7 to about 1 .1 , meters (m), or any range between the lowest and highest of these values. The module 20 is not limited to any particular shape, length or width.

[0065] Referring to FIG. 9, another embodiment of the module 20 is depicted. The module 20 includes PV cells 36a, 36b and tabbing ribbons 48 disposed between the substrate 24 and cover sheet 30. Polymeric strips 66 are disposed adjacent the tabbing ribbons 48. In these embodiments, the polymeric strips 66 are generally disposed parallel relative to the direction of the tabbing ribbons 48. The polymeric strips 66 can be formed from the first polymeric composition. A tie-layer 68 is disposed between the substrate 24 and the cover sheet 30. Portions of the tie-layer 68 are also disposed between the polymeric strips 66, the PV cells 36a, and the cover sheet 30. The tie-layer 68 can be formed from the second polymeric composition. In further embodiments (not shown), the module 20 of Fig. 9 can further include the polymeric strips 54, 56 as described above.

[0066] In further embodiments (not shown), the module 20 can further include a "peripheral tie-layer" as described in U.S. Pat. App. Ser. No. 61 /591005 (Attorney Docket No. DC1 1205 PSP1 ; 071038.00787), and/or "polymeric strips" as described in U.S. Pat. App. Ser. No. 61 /591000 (Attorney Docket No. DC1 1226 PSP1 ; 071038.0081 1 ), the disclosures of which are incorporated by reference in their entirety to the extent they do not conflict with the general scope of the present invention. If any conflict exists between the instant disclosure and any of the incorporated reference(s), only the portion(s) of any of the incorporated reference(s) that are in conflict with the instant disclosure, rather than an entirety of any of the incorporated reference(s), are expunged from incorporation herein from the incorporated reference(s). In yet further embodiments (not shown), the module 20 can include additional components, e.g. at least one spacer disposed along the perimeter. Such components are described in the incorporated references.

[0067] The invention method of forming the invention module 20 comprises the step of applying the first polymeric composition to first and second portions of the rear face 34 of the cover sheet 30 to form the first and second polymeric strips 54, 56. At this application stage, the first and second polymeric strips 54, 56 are generally in an uncured state, e.g. liquid form, to promote ease of application. As shown in FIG. 5, the portions are spaced from one another, and there are portions for each of the polymeric strips 54, 56. The first polymeric composition can be applied to the rear face 34 by various means, such as by spraying, dispensing, flow coating, injecting, etc.

[0068] In other embodiments, the first and second polymeric strips 54, 56 are pre-formed and disposed on the rear face 34 of the cover sheet 30. For example, a polymeric sheet can be made from the first polymeric composition and cut into the polymeric strips 54, 56, or the polymeric strips can be pre-made from the first polymeric composition and disposed on the rear face 34 of the cover sheet 30. In certain embodiments, the first polymeric composition is dispensed (or disposed) on the rear face 34 robotically.

[0069] As shown in FIG. 5, a robotic dispenser 60 is shown applying the first polymeric composition to the cover sheet 30 such that gaps are left on the rear face 34 of the cover sheet 30. The robotic dispenser 60 typically has one or more nozzles 62, from which the first polymeric composition dispenses. The nozzles 62 can be selectively turned on or off to provide polymeric strips 54, 56 of various widths. As such, one or more nozzles 62 may be used to form each of the polymeric strips 54, 56. The first and second polymeric strips 54, 56 may be formed separately or simultaneously, i.e., at the same or at different times. The robotic dispenser 60 can be on a track and/or arm (not shown) and programmed to move along the length and/or width of the cover sheet 30 to form the polymeric strips 54, 56. In the alternative, the cover sheet 30 can also be moved relative to the robotic dispenser 60, or both can move relative to each other.

[0070] The first polymeric composition can be applied to the cover sheet 30 in various amounts. For example, the first polymeric composition can be applied such that each of the polymeric strips 54, 56 has a thickness of from about 0.125 to about 0.7 mm on average and a width of from about 1 .25 to about 13 mm on average, or any range between the lowest and highest of these values. Each of the polymeric strips 54, 56 may have the same or different dimensions.

[0071] After the first polymeric composition is applied to the cover sheet 30 to form the polymeric strips 54, 56, the PV cells 36, 38 are disposed on the polymeric strips 54, 56. Specifically, the first PV cell 36 is disposed over the first polymeric strip 54 and the second PV cell 38 is disposed over the second polymeric strip 56. The polymeric strips 54, 56 can be allowed to level prior to disposing the PV cells 36, 38 to prevent gaps, voids, or other issues. The PV cells 36, 38 may be disposed separately or simultaneously.

[0072] As shown in FIG. 6, the tabbing ribbon 48 operatively connects the PV cells 36, 38. The tabbing ribbon 48 may be connected after disposing the PV cells 36, 38, alternatively, prior to disposing the PV cells 36, 38. [0073] The PV cells 36, 38 may be disposed by various means, such as by hand or robotic grip 64. The robotic grip 64 can use vacuum or other means to hold the PV cells 36, 38. The robotic grip 64 can be operatively connected to a track and/or arm (not shown) for movement. The PV cells 36, 38 can simply be placed on top of the polymeric strips 54, 56 or slightly pressed into the polymeric strips 54, 56. Pressing generally ensures that no gaps or voids are present between the respective polymeric strip 54, 56 and the respective PV cell 36, 38.

[0074] The polymeric strips 54, 56 may be cured (to a final cure state or partially thereto) prior to or after the PV cells 54, 56 are disposed. For example, the polymeric strips 54, 56 can be cured via oven prior to disposing the PV cells 36, 38. Applying heat to the polymeric strips 54, 56 generally facilitates cure of the polymeric strips from an uncured state to a final cured state. In certain embodiments, the polymeric strips 54, 56 are generally at a viscosity, at the time of disposing the PV cells 36, 38, which allows for any air that may be trapped between the polymeric strips 54, 56 and the PV cells 36, 38 to migrate outwardly from therebetween. In this way, bubbles are not formed and/or trapped, as bubbles could create negative issues for the module 20. The viscosity can be an initial viscosity of the first polymeric composition (i.e., pre-cure), or a higher viscosity that arises after at least partial cure of the polymeric strips 54, 56. While not required, these embodiments may be useful in instances where the module 20 is cured via a vacuum-press process.

[0075] Typically, after the PV cells 36, 38 are disposed, the second polymeric composition is applied over the rear face 34 of the cover sheet 30 between the polymeric strips 54, 56 and over the PV cells 36, 38 and over the tabbing ribbon 48 to form the tie-layer 58. At this application stage, the tie-layer 58 is generally in an uncured state, e.g. liquid form, to promote ease of application. The second polymeric composition can be applied by various means, such as by spraying, dispensing, flow coating, injecting, etc. In certain embodiments, the second polymeric composition is dispensed robotically.

[0076] In certain embodiments, a portion of the second polymeric composition is applied into the gaps which were left on the rear face 34 of the cover sheet 30 during application of the first polymeric composition prior to disposing the PV cells 36, 38. In these embodiments, the second polymeric composition may be applied after or simultaneous with the first polymeric composition. After application, at least one of the first and second polymeric compositions can be allowed to level and/or be cured as like described above prior to disposing the PV cells 36, 38. In other embodiments described below, all of the second polymeric composition is applied after the PV cells 36, 38 are disposed. [0077] As shown in FIG. 7, the robotic dispenser 60 is shown applying the second polymeric composition to the cover sheet 30. The robotic dispenser 60 can be the same or different than the robotic dispenser 60 that applies the first polymeric composition. The robotic dispenser 60 can be on a track or arm (not shown) and programmed to move along the length and/or width of the cover sheet 30 to form the tie-layer 58. In the alternative, the cover sheet 30 can also be moved relative to the robotic dispenser 60, or both can be moved relative to each other. The nozzles 62 can be selectively turned on or off to control application amount and location of the second polymeric composition.

[0078] The second polymeric composition can be applied in various amounts to form the tie-layer 58. Typically, the second polymeric composition is applied such that the tie-layer 58 has a thickness of from about 0.2 to about 1 .25 mm on average, or any range between these values.

[0079] After all of the second polymeric composition is applied, the substrate 24 and the cover sheet 30 are combined to form the module 20. The substrate 24 and cover sheet 30 can be combined in various ways. For example, the substrate 24 can be laid over the tie- layer 58 to form the module 20. As shown in FIG. 8, the substrate 24 is laminated over the tie-layer 58 to form the module 20. In certain embodiments, the intermediate layer (not shown) is laid on the tie-layer 58 before the substrate 24 is laid. The intermediate layer may also be referred to in the art as a spacer layer.

[0080] In certain embodiments, the tie-layer 58 is generally at a viscosity, at the time of combining the substrate 24 and the cover sheet 30, which allows for any air that may be trapped within/by the tie-layer 58 to migrate outwardly therefrom. In this way, bubbles are not formed and/or trapped, as bubbles could create issues for the module 20. The viscosity can be an initial viscosity of the second polymeric composition (i.e., pre-cure), or a higher viscosity that arises after at least partial cure of the tie-layer 58. While not required, these embodiments may be useful in instances where the module 20 is cured via a vacuum- press process.

[0081 ] The silicone composition used to form the tie-layer 58 typically has a complex (dynamic) viscosity of from 10,000 to 5,000,000 cPs at 25°C measured at 1 radian per second at 1 to 5% strain. More specifically, a Frequency Sweep is generated on a TA Instruments, HR-2 parallel plate Rheometer. A sample is loaded between two 25 mm parallel plates to a 2 mm thickness. The frequency sweep is run from 0.1 rad/sec to 100 rad/sec at a 5% strain, the dynamic (complex) viscosity is reported at 1 rad/sec in cP. In other embodiments, the complex viscosity is from 15,000 to 100,000, from 20,000 to 95,000, from 25,000 to 90,000, from 30,000 to 85,000, from 35,000 to 75,000, from 40,000 to 70,000, from 45,000 to 65,000, from 50,000 to 60,000, or from 55,000 to 60,000, cPs at 25°C measured as described above. In other embodiments, the complex viscosity is from 50,000 to 100,000, from 55,000 to 95,000, from 60,000 to 90,000, from 65,000 to 85,000, from 70,000 to 80,000, or from 75,000 to 80,000, cPs at 25°C measured as described above.

[0082] In still other embodiments, the complex viscosity is from 35,000 to 300,000, from 40,000 to 295,000, from 45,000 to 290,000, from 50,000 to 285,000, from 55,000 to 280,000, from 60,000 to 275,000, from 65,000 to 275,000, from 70,000 to 270,000, from 75,000 to 265,000, from 80,000 to 260,000, from 85,000 to 255,000, from 90,000 to 250,000, from 95,000 to 245,000, from 100,000 to 240,000, from 105,000 to 235,000, from 1 10,000 to 230,000, from 1 15,000 to 225,000, from 120,000 to 220,000, from 125,000 to 215,000, from 130,000 to 210,000, from 135,000 to 205,000, from 140,000 to 200,000, from 145,000 to 195,000, from 150,000 to 190,000, from 155,000 to 185,000, from 160,000 to 180,000, from 165,000 to 175,000, or from 165,000 to 170,000, from 80,000 to 200,000, from 40,000 to 200,000, or from 40,000 to 300,000, cPs at 25°C measured as described above.

[0083] In still other embodiments, the complex viscosity is from 100,000 to 1 ,000,000, from 125,000 to 975,000, from 150,000 to 950,000, from 175,000 to 925,000, from 200,000 to 900,000, from 225,000 to 875,000, from 250,000 to 850,000, from 275,000 to 825,000, from 300,000 to 800,000, from 325,000 to 775,000, from 350,000 to 750,000, from 375,000 to 725,000, from 400,000 to 700,000, from 425,000 to 675,000, from 450,000 to 650,000, from 475,000 to 625,000, from 500,000 to 600,000, from 525,000 to 575,000, or from 550,000 to 575,000, cPs at 25°C measured as described above.

[0084] In even further embodiments, the complex viscosity is from 1 ,125,000 to 1 ,975,000, from 1 ,150,000 to 1 ,950,000, from 1 ,175,000 to 1 ,925,000, from 1 ,200,000 to 1 ,900,000, from 1 ,225,000 to 1 ,875,000, from 1 ,250,000 to 1 ,850,000, from 1 ,275,000 to 1 ,825,000, from 1 ,300,000 to 1 ,800,000, from 1 ,325,000 to 1 ,775,000, from 1 ,350,000 to 1 ,750,000, from 1 ,375,000 to 1 ,725,000, from 1 ,400,000 to 1 ,700,000, from 1 ,425,000 to 1 ,675,000, from 1 ,450,000 to 1 ,650,000, from 1 ,475,000 to 1 ,625,000, from 1 ,500,000 to 1 ,600,000, from 1 ,525,000 to 1 ,575,000, from 1 ,550,000 to 1 ,575,000, from 2,125,000 to 2,975,000, from 2,150,000 to 2,950,000, from 2,175,000 to 2,925,000, from 2,200,000 to 2,900,000, from 2,225,000 to 2,875,000, from 2,250,000 to 2,850,000, from 2,275,000 to 2,825,000, from 2,300,000 to 2,800,000, from 2,325,000 to 2,775,000, from 2,350,000 to 2,750,000, from 2,375,000 to 2,725,000, from 2,400,000 to 2,700,000, from 2,425,000 to 2,675,000, from 2,450,000 to 2,650,000, from 2,475,000 to 2,625,000, from 2,500,000 to 2,600,000, from 2,525,000 to 2,575,000, from 2,550,000 to 2,575,000, from 3,125,000 to 3,975,000, from 3,150,000 to 3,950,000, from 3,175,000 to 3,925,000, from 3,200,000 to 3,900,000, from 3,225,000 to 3,875,000, from 3,250,000 to 3,850,000, from 3,275,000 to 3,825,000, from 3,300,000 to 3,800,000, from 3,325,000 to 3,775,000, from 3,350,000 to 3,750,000, from 3,375,000 to 3,725,000, from 3,400,000 to 3,700,000, from 3,425,000 to 3,675,000, from 3,450,000 to 3,650,000, from 3,475,000 to 3,625,000, from 3,500,000 to 3,600,000, from 3,525,000 to 3,575,000, from 3,550,000 to 3,575,000, from 4,125,000 to 4,975,000, from 4,150,000 to 4,950,000, from 4,175,000 to 4,925,000, from 4,200,000 to 4,900,000, from 4,225,000 to 4,875,000, from 4,250,000 to 4,850,000, from 4,275,000 to 4,825,000, from 4,300,000 to 4,800,000, from 4,325,000 to 4,775,000, from 4,350,000 to 4,750,000, from 4,375,000 to 4,725,000, from 4,400,000 to 4,700,000, from 4,425,000 to 4,675,000, from 4,450,000 to 4,650,000, from 4,475,000 to 4,625,000, from 4,500,000 to 4,600,000, from 4,525,000 to 4,575,000, or from 4,550,000 to 4,575,000, cPs at 25°C measured as described above.

[0085] Any one or more of the aforementioned values can be increased by an order of magnitude. As just one example, the silicone composition may have a complex viscosity of from 10,000 to 50,000,000 cPs at 25°C measured as described above. Any of the aforementioned values may, for example, vary by 1 , 2, 3, 4, 5, 10, 15, 20, or 25+ % in varying non-limiting embodiments. All values, and ranges of values, between and including the aforementioned values are also hereby expressly contemplated in various non-limiting embodiments. The aforementioned viscosity is the complex viscosity of the silicone composition before curing. After curing, the cured reaction product is typically a solid but may also be a gel.

[0086] In various embodiments, the second polymeric composition is applied in a pattern defining at least one passage (not shown) extending from an interior of module 20 to a perimeter of the module 20 to form the tie-layer 58. The pattern is not particularly limited and may be further described as a geometric, non-geometric, uniform or non-uniform pattern. In one embodiment, the silicone composition is deposited in one, two, or a plurality of rows. One or more of the rows may be disposed substantially parallel or traverse (i.e., at an angle) with one or more other rows. For example, the passages formed from the silicone composition may extend to opposing or different locations on the perimeter of the module 20. This may be achieved based on the disposition of the one or more rows of the silicone composition.

[0087] In other embodiments, patterning can be used for the first polymeric composition, in addition or alternate to the second polymeric composition. In general, patterning is useful for the more viscous/heavier of the two polymeric compositions. Further examples of suitable patterns/patterning methodology, as well as the benefits thereof, include those described in the incorporated '277 application.

[0088] The passage is also not particularly limited. Typically, the passage is defined on two or more sides by the deposition of the silicone composition. The passage may alternatively be described as a conduit, duct, fluting, furrow, gouge, groove, gutter, pass, passage, trough, channel, lane, opening, or pathway.

[0089] The passage extends from an interior of the module 20 to the perimeter (e.g. an exterior) of the module 20 and may originate at any point on the interior of the module 20. The passage may extend across an entirety of the interior or across a portion of the interior. The passage may extend to two or more points on the perimeter of the module 20 or a single point. The passage may be further defined as one, two, or a plurality of individual passages that may be connected or not connected to each other in whole or in one or more parts. Air, e.g. from bubbles, may pass through the passage to the perimeter of the module 20 before the deposited silicone composition defining the passage merges together to fill in and thereby eliminate the passage. Typically, the passage is defined such that air can pass through the passage and exit the module 20 to reduce or eliminate the presence of any air bubbles in one or more layers, e.g. the tie-layer 58. Said differently, the passage typically allows air to flow from an interior of the module 20 (e.g. from a center), out towards a perimeter of the module 20 (e.g. to the edges), thereby minimizing the amount of air trapped in the module 20 in any one or more layers or components.

[0090] Pressure and/or heat can be applied to the module 20 for a period of time during and/or after combining the substrate 24 and the cover sheet 30 to further form the module 20. If both pressure and heat are employed, the pressure and heat can be applied separately or simultaneously. Application of heat is useful for curing the tie-layer 58, and optionally, the polymeric strips 54, 56, to a final cure state. These steps may be referred to in the art as press curing or lamination. Examples of suitable lamination techniques include vacuum or atmospheric lamination, and can include the application of heat. Specific examples of such processes, e.g. vacuum lamination, as well as other optional steps, are described in some of the incorporated references.

[0091] In certain embodiments, the module 20 is formed with application of heat. Suitable temperatures are of from about 20 to about 200, about 40 to about 150, or about 70 to about 1 10, °C, or any range between the lowest and highest of these values. In certain embodiments, the module 20 is formed with application of pressure. Suitable pressures are of from about 7 to about 350, about 20 to about 200, or about 30 to about 140, kPa, or any range between the lowest and highest of these values. Various combinations of temperature and pressure can be used, or only one of temperature and pressure can be used to form the module 20.

[0092] Specific embodiments of forming the module 20 are as follows. The first polymeric composition is dispensed onto portions of the rear face 34 of the cover sheet 30 to form the polymeric strips 54, 56 such that gaps defined between the polymeric strips 54, 56, which are aligned between the PV cells 36, 38 (not yet disposed). The polymeric strips 54, 56 are allowed to level and are then cured via oven. Alternatively, the polymeric strips 54, 56 are pre-formed and disposed on the rear face 34 of the cover sheet 30. The PV cells 36, 38 are then pressed into the polymeric strips 54, 56. Optionally, a portion the second polymeric composition is dispensed into the gaps and cured via oven to form a potion of the tie-layer 58 before pressing the PV cells 36, 38. Alternatively, all of the second polymeric composition is dispensed over the PV cells 36, 38 thereby filling the gaps and forming the tie-layer 58. Next, the intermediate layer, e.g. nonwoven FG, is laid over the tie-layer 58, and the substrate 24 is laid over the intermediate layer to from the module 20. The module 20 is then press cured. For example, the module 20 can be cured via a lamination process, vacuum-lamination process, etc.

[0093] One or more of the values described above may vary by ±5%, ±10%, ±15%, ±20%, ±25%, etc. so long as the variance remains within the scope of the disclosure. Unexpected results may be obtained from each member of a Markush group independent from all other members. Each member may be relied upon individually and or in combination and provides adequate support for specific embodiments within the scope of the appended claims. The subject matter of all combinations of independent and dependent claims, both single and multiple dependent, is herein expressly contemplated. The disclosure is illustrative including words of description rather than of limitation. Many modifications and variations of the present disclosure are possible in light of the above teachings, and the disclosure may be practiced otherwise than as specifically described herein.

Claims

CLAIMS What is claimed is:

1 . A photovoltaic (PV) cell module comprising:

a substrate having a front face and a rear face spaced from said front face of said substrate;

a cover sheet having a front face and a rear face spaced from said front face of said cover sheet;

a first PV cell disposed between said substrate and said cover sheet with said first PV cell having a front face and a rear face spaced from said front face of said first PV cell; a second PV cell disposed between said substrate and said cover sheet and disposed adjacent said first PV cell with said second PV cell having a front face and a rear face spaced from said front face of said second PV cell;

a tabbing ribbon disposed between said PV cells with said tabbing ribbon having a first end operatively connected to said front face of said first PV cell and a second end operatively connected to said rear face of said second PV cell;

a first polymeric strip formed from a first polymeric composition and disposed between said first PV cell and said cover sheet for coupling said front face of said first PV cell to said rear face of said cover sheet;

a second polymeric strip also formed from said first polymeric composition and disposed between said second PV cell and said cover sheet for coupling said front face of said second PV cell to said rear face of said cover sheet; and

a tie-layer formed from a second polymeric composition different than said first polymeric composition and disposed between said substrate and said cover sheet and between said polymeric strips for coupling said rear face of said cover sheet to said front face of said substrate and for coupling said rear faces of said PV cells to said front face of said substrate.

2. The module as set forth in claim 1 wherein:

i) a modulus of elasticity of said tie-layer is greater than a modulus of elasticity of said polymeric strips;

ii) a modulus of elasticity of said tie-layer is from about 15 to about 50 kilopascals (kPa) and a modulus of elasticity of said polymeric strips is from about 0.5 to about 12.5 kPa;

iii) a modulus of elasticity of said tie-layer is from about 50 to about 2000 kilopascals (kPa) and a modulus of elasticity of said polymeric strips is from about 0.5 to about 12.5 kPa; iv) both i) and ii); or

v) both i) and iii).

3. The module as set forth in claim 1 or 2, wherein:

i) each of said polymeric strips has a thickness of from about 0.125 to about 0.75 millimeters (mm) on average and a width of from about 5 to about 13 mm on average; and/or

ii) said tie-layer has a thickness of from about 0.25 to about 1 .25 mm on average.

4. The module as set forth in any one of the preceding claims, wherein:

i) said tabbing ribbon is encapsulated by said tie-layer;

ii) said PV cells are substantially coplanar;

iii) each of said polymeric strips has a substantially rectangular-shaped cross- section; and/or

iv) said polymeric strips are disposed transverse relative to said tabbing ribbon.

5. The module as set forth in any one of the preceding claims, wherein said:

i) cover sheet is formed from glass; and/or

ii) substrate is formed from glass, a polymeric material, or a composite material.

6. The module as set forth in any one of the preceding claims, wherein each of said first and second polymeric compositions are hydrosilylation-reaction curable silicone compositions.

7. The module as set forth in any one of the preceding claims, wherein said:

i) first polymeric composition comprises greater than about 45 parts by weight of a diorganopolysiloxane having alkenyl groups, from about 2.5 to about 7.5 parts by weight of an organosilicon hydride having silicon-bonded hydrogen atoms reactive with said diorganopolysiloxane, and from about 25 to about 65 parts by weight of a non-reactive organopolysiloxane, each based on 100 parts by weight of said first polymeric composition; and/or

ii) second polymeric composition comprises greater than about 55 parts by weight of a diorganopolysiloxane having alkenyl groups and from about 5 to about 25 parts by weight of an organosilicon hydride having silicon-bonded hydrogen atoms reactive with said diorganopolysiloxane, each based on 100 parts by weight of said second polymeric composition.

8. The module as set forth in any one of claims 1 -7, wherein said first polymeric composition comprises:

two different dimethylvinyl-terminated polydimethylsiloxanes;

a dimethylhydrogen-terminated polydimethylsiloxane; and

a trimethylsiloxy-terminated dimethyl methylhydrogen siloxane containing at least 3 SiH units per molecule.

9. The module as set forth in any one of claims 1 -8, wherein said second polymeric composition comprises:

i) a dimethylvinyl-terminated polydimethylsiloxane, a dimethylhydrogen- terminated polydimethylsiloxane, and a trimethylsiloxy-terminated dimethyl methylhydrogen siloxane containing at least 3 SiH units per molecule; or

ii) a dimethylvinyl-terminated polydimethylsiloxane, and a trimethylsiloxy- terminated dimethyl methylhydrogen siloxane containing at least 3 SiH units per molecule.

10. A method of forming a photovoltaic (PV) cell module comprising a substrate having a front face and a rear face spaced from the front face of the substrate, a cover sheet having a front face and a rear face spaced from the front face of the cover sheet with the rear face having a first portion and a second portion spaced from the first portion, a first PV cell disposed between the substrate and the cover sheet with the first PV cell having a front face and a rear face spaced from the front face of the first PV cell, a second PV cell disposed between the substrate the cover sheet and disposed adjacent the first PV cell with the second PV cell having a front face and a rear face spaced from the front face of the second PV cell, a tabbing ribbon disposed between the PV cells with the tabbing ribbon having a first end operatively connected to the front face of the first PV cell and a second end operatively connected to the rear face of the second PV cell, a first polymeric strip disposed between the first PV cell and the rear face of the cover sheet for coupling the front face of the first PV cell to the first portion of the rear face of the cover sheet, a second polymeric strip disposed between the second PV cell and the rear face of the cover sheet for coupling the front face of the second PV cell to the second portion of the rear face of the cover sheet, and a tie-layer disposed between the substrate and the cover sheet and between the polymeric strips for coupling the rear face of the cover sheet to the front face of the substrate and for coupling the rear faces of the PV cells to the front face of the substrate, said method comprising the steps of: applying a first polymeric composition to the first and second portions of the rear face of the cover sheet to form the first and second polymeric strips in an uncured state; optionally, curing the polymeric strips to a cured state;

disposing the first and second PV cells on the first and second polymeric strips with the tabbing ribbon operatively connecting the first and second PV cells;

applying a second polymeric composition different than the first polymeric composition over the rear face of the cover sheet between the polymeric strips and over the PV cells and over the tabbing ribbon to form the tie-layer in an uncured state; and

combining the substrate and the cover sheet to form the PV cell module.

1 1 . The method as set forth in claim 10 wherein the polymeric strips are cured prior to disposing the PV cells.

12. The method as set forth in claim 10 or 1 1 , wherein the:

i) first and second polymeric strips are formed simultaneously; and/or ii) first and second PV cells are disposed simultaneously.

13. The method as set forth in any one of claims 10-12, further comprising the step(s) of:

applying pressure to the PV cell module for a period of time during and/or after combining the substrate and the cover sheet to further form the PV cell module; and/or applying heat to the PV cell module for a period of time during and/or after combining the substrate and the cover sheet to further form the PV cell module.

14. The method as set forth in any one of claims 10-13, wherein:

i) the steps of applying are further defined as dispensing the first and second polymeric compositions via a robotic dispenser; and/or

ii) the step of curing is further defined as applying heat to the polymeric strips for facilitating cure of the polymeric strips from the uncured state to the cured state.

15. The method as set forth in any one of claims 10-14, wherein the:

i) first polymeric composition is applied such that each of the polymeric strips has a thickness of from about 0.125 to about 0.75 millimeters (mm) on average and a width of from about 5 to about 13 mm on average; and/or

ii) second polymeric composition is applied such that tie-layer has a thickness of from about 10 to about 50 mils.