METHOD OF MANUFACTURING A PHOTOVOLTAIC CELL MODULE
[0001] This invention comprises a method of manufacturing a photovoltaic cell module, the
photovoltaic (PV) cell module manufactured thereby, and a kit useful therefor.
[0002] Known methods of manufacturing photovoltaic cell modules include those of US
5 4,224,081; US 2006/0207646 A1; US 2010/0275992 A1; and US 2011/0203664 A1. A
typical method includes vacuum-press-curing (V-P-C) a laminate. The laminate sequentially
comprises a superstrate, a front portion of an encapsulant, interconnected PV cells, a rear
portion of the encapsulant, and a substrate. For example, the method of US 2010/0275992
A1 mentions, inter alia, an ultrahigh durability solar cell module that can be used semi10
permanently, with an ultrahigh durability transparent substrate, solar cell element and filler,
wherein the solar cell element and a liquid substance or a gel obtained by a fast sealed
structure comprising a high durability crosslinking reactive adhesive provided between a
glass panel and back side protective substrate, and a hot-melt adhesive. The module is
produced by placing the sealing compound, solar cell element and liquid substance on a
15 glass panel and finally laying the back side protective substance to form a provisional
laminated body, and then compression bonding the provisional laminated body at room
temperature in a vacuum for sealing.
[0003] A focus in the art has been building laminates for use in V-P-C equipment. These
laminates are assembled from the ground up by sequentially laying one of a substrate or
20 superstrate down in a horizontal orientation, dispensing a liquid encapsulant on the substrate
or superstrate, laying PV cells on the dispensed encapsulant, interconnecting the PV cells if
not already done, dispensing more liquid encapsulant on the interconnected PV cells, and
then laying the other of the substrate or superstrate, as the case may be, on the second
dispensed encapsulant until the laminate is assembled. The assembled laminate is then
25 vacuum-press-cured horizontally to minimize leakage of the liquid encapsulant from the
laminate. An overriding a goal of this work is producing hectowatt-sized (0.1 to < 1 kilowatt)
PV cell modules at ever higher output rates and ever lower manufacturing costs. This focus
does not meet all industry needs.
[0004] Also, in addition to its high costs, the inventors discovered technical problems with
30 manufacturing PV cell modules using V-P-C equipment. For example, the V-P-C method
traps air bubbles during evacuation (V step) of the assembled laminate. Air bubbles reduce
module efficiency. Also, the V-P-C methods use more encapsulant than is necessary for
coating or encapsulating the PV cells. The extra encapsulant oozes out of the module during
the pressing (P) step, rendering the V-P-C method inefficient. Sometimes the V-P-C method
DC11750NP1
2
cracks the PV cells and/or breaks the interconnections. Any given V-P-C method may have
one or more of these problems.
[0005] Further, there is a huge unmet need for electricity in the world. A total of 1.4 billion
low income people live off-grid in diverse geographical locations that lack (reliable) access to
electricity. A 5 large proportion of these people live in remote sunny regions that are far from
PV cell module manufacturing plants and distribution channels.
[0006] Our efforts to find a way to bring affordable electricity to these indigenous off-grid
people unexpectedly led us to a technical solution to the V-P-C manufacturing problems. We
believe that our technical solution is not taught, disclosed, or suggested by the cited art.
10 BRIEF SUMMARY OF THE INVENTION
[0007] This invention comprises a method of manufacturing a photovoltaic (PV) cell module,
the PV cell module manufactured thereby, and a kit useful therefor. Embodiments of the
invention include:
[0008] A method of manufacturing a PV cell module, the method comprising introducing a
15 liquid encapsulant between a superstrate and interconnected PV cells and between the
interconnected PV cells and a substrate in a preassembled laminate sequentially comprising
the superstrate, interconnected PV cells, and substrate, and lacking encapsulant before the
introducing step, the method giving a first PV cell module sequentially comprising the
superstrate, a front portion of the liquid encapsulant, interconnected PV cells, a rear portion
20 of the liquid encapsulant, and the substrate.
[0009] The PV cell module prepared by the method.
[0010] A kit comprising components of the PV cell module and instructions for using same to
manufacture the module according to the method.
[0011] The method is useful for manufacturing PV cell modules. The manufactured PV cells
25 modules are useful in a variety of applications. The kit is useful in the method. The invention
may have additional uses, including those unrelated to PV applications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Embodiments of the invention and certain advantages may be illustrated and
described by referring to the accompanying drawings.
30 [0013] Figure (Fig.) 1 is a perspective view of an embodiment of a partial assembly to the
preassembled laminate.
[0014] Fig. 2 is a partially-exploded perspective view of an embodiment of the preassembled
laminate prepared from the partial assembly of Fig. 1.
DC11750NP1
3
[0015] Fig. 3 is a perspective view of another embodiment of the preassembled laminate.
[0016] Fig. 4 is a partially exploded view of the embodiment of the preassembled laminate of
Fig. 2.
[0017] Fig. 5 is a perspective view of the embodiment of the preassembled laminate of Fig.
5 2 shown during the introducing step of the method.
[0018] Fig. 6 is a perspective view of an embodiment of the PV cell module prepared from
the preassembled laminate of Fig. 5.
[0019] Fig. 7 is a perspective view of another embodiment of the preassembled laminate
shown during the introducing step of the method.
10 [0020] Fig. 8 is a perspective view of an embodiment of the PV cell module prepared from
the preassembled laminate of Fig. 7.
[0021] Fig. 9 is a perspective view of an alternate embodiment of a partial assembly to the
preassembled laminate.
[0022] Fig. 10 is a perspective view of another embodiment of the preassembled laminate.
15 [0023] Fig. 11 is a perspective view of an embodiment of the PV cell module prepared from
the preassembled laminate of Fig. 10.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The Brief Summary and Abstract are incorporated here by reference. The invention
embodiments include the method, PV cell module, and kit summarized above. The invention
20 also includes other embodiments described below. The term “preassembled laminate
consisting essentially of” may be used herein to mean that prior to the introducing step the
preassembled laminate lacks encapsulant and the PV cells are not encapsulated, and thus
are in need of encapsulation.
[0025] The invention has technical advantages. For example, the method may manufacture
25 a bubble-free PV cell module, which lacks bubbles trapped in the liquid encapsulant. That is,
the liquid encapsulant may be allowed to coat the PV cells in such a way that any initial
bubbles are allowed to break, float away, be absorbed, or a combination of any two or more
thereof. Additionally or alternatively, the method may form a layer of the front portion of the
liquid encapsulant of a uniform thickness between the superstrate and the PV cells and a
30 layer of the rear portion of the liquid encapsulant of uniform thickness between the PV cells
and the substrate without use of a vacuum and/or cell press. Additionally or alternatively, the
method may prevent oozing or loss of the liquid encapsulant from the preassembled
laminate and/or PV cell module. That is, the effective amount of the liquid encapsulant that is

used in the method may be the quantity desired for coating the PV cells, without any excess
quantity being used and lost. Additionally or alternatively, the method may be performed at
ambient pressure, e.g., at 96 to 106 kilopascals. Additionally, the method is gentle and
avoids cracking the PV cells and/or breaking the electrical interconnections.
5 [0026] Beneficially, the method may be performed without vacuum and a cell press
machine. Therefore, the method may be used by millions of low income people who live offgrid
in remote sunny regions in diverse geographical locations that lack (reliable) access to
electricity. That is, the method enables these indigenous people in India, Africa, the Middle
East and other remote areas to produce their own PV cell module to meet their need for
10 electricity where they live without relying on access to PV cell module manufacturing plants
and distribution channels. Certain aspects of this invention may independently solve
additional problems and/or have other advantages.
[0027] Invention embodiments and some of these advantages may be illustrated in the
accompanying drawings and/or described herein. The method is illustrated by the Figures
15 and described below with reference to an embodiment wherein the liquid encapsulant is
poured by hand onto a plurality of interconnected PV cells. The invention includes other
means of introducing the liquid encapsulant such as by spraying, dripping, or squirting.
[0028] In the Figure(s), like numerals indicate like parts throughout.
[0029] Fig. 1 shows the perspective view of an embodiment of a partial assembly to the
20 preassembled laminate. In Fig. 1, the partial assembly 10 lacks the superstrate and the seal
(both not shown). The partial assembly 10 comprises a substrate 20, thirty-six PV cells 30,
interconnection circuit comprising five horizontally disposed bus bars 49, a plurality of
vertically disposed interconnects 40, bus bar connects 42 and 44, and four corner spacer/tie
elements 50. Interconnects 40, bus bar connects 42 and 44 and bus bars 49 may comprise
25 the same or different electrically conductive metal or metal alloy (e.g., Al, Ag, Cu, or alloy
thereof). Together the PV cells 30, interconnection circuit (40 and 49), bus bar connects 42
and 44 comprise an interconnected PV cells subassembly (not indicated). The substrate 20
has a first major surface 22 and a second major surface 28, which is spaced apart from the
first major surface 22 by the thickness (not indicated) of the substrate 20. The substrate 20
30 defines apertures 41 and 43 therethrough. Each of the PV cells 30 (only two are numbered
for clarity) has a first major surface 32 and a second major surface 38, which is spaced apart
from the first major surface 32 by the thickness (not indicated) of the PV cell 30. The PV
cells 30 are disposed on the second major surface 28 of the substrate 20 such that the first
major surfaces 32 of the PV cells 30 are facing the second major surface 28 of the substrate
DC11750NP1
5
20. The interconnection circuit (40 and 49), and thus the PV cells 30, are affixed to the
second major surface 28 of the substrate 20 using five pieces of tape 51 applied to spaced
apart locations on the interconnection circuit (40 and 49). The PV cells 30 are electrically
interconnected and in electrical communication with each other via the interconnection circuit
(40 and 49). The interconnection ci 5 rcuit (40 and 49) in turn is electrically interconnected and
in electrical communication with bus bar connects 42 and 44. Bus bar connect 42 is
electrically interconnected with bus bar connect 44 via the interconnection circuit (40 and
49). Bus bar connects 42 and 44 travel from interconnection circuit (40 and 49) at second
major surface 28 through apertures 41 and 43, respectively, of substrate 20 to exit substrate
10 20 at first major surface 22 thereof. If desired, a seal such as a piece of tape or a plug of
elastomer (not shown) may be applied to substrate 20 to cover apertures 41 and 43 (e.g.,
tape applied over apertures 41 and 43 on first major surface 22) to prevent leakage of liquid
encapsulant therethrough during the introducing step of the method. Bus bar connects 42
and 44 may later serve to make an external, back side electrical interconnection to a junction
15 box, electrical grid, or electrical device. The four corner spacer/tie elements 50 are disposed
at the four corners on the second major surface 28 of the substrate 20.
[0030] Fig. 2 shows the partially-exploded perspective view of an embodiment 100 of the
preassembled laminate. In Fig. 2, the preassembled laminate 100 comprises the substrate
20, the thirty-six PV cells 30, interconnection circuit (40 and 49), bus bar connects 42 and
20 44, and four corner spacer/tie elements 50 from the partial assembly 10 of Fig. 1. The
preassembled laminate 100 also comprises a superstrate 60, three pieces of sealing tape
70, and a rigid spacer element 55. The superstrate 60 is spaced apart from substrate 20 by
the four corner spacer/tie elements 50 and the rigid spacer element 55. The four corner
spacer/tie elements 50 may be double-sided tape. The superstrate 60 has a first major
25 surface (62 in Fig. 4) and a second major surface 68, which is spaced apart from the first
major surface (62 in Fig. 4) by the thickness (not indicated) of the superstrate 60. The four
corner spacer/tie elements 50 space apart the second major surface (28 in Fig. 1 or 4) of the
substrate 20 from the first major surface (62 in Fig. 4) of the superstrate 60. The thickness
(not indicated) of the four corner spacer/tie elements 50 may be slightly greater than the
30 thickness (not indicated) of the PV cells 30. Sealing tape 70 wraps around and seals edges
82, 84, and 86 of the preassembled laminate 100. Sealing tape 70 has a partially-exploded
section 74 that shows the sealing tape 70 is [-shaped for contacting superstrate 60, edges
82, 84, and 86, and substrate 20. Bus bar connects 42 and 44 travel from two of bus bars 49
of interconnection circuit (40 and 49) at second major surface 28 of substrate 20 (interior in
DC11750NP1
6
the preassembled laminate 100) through apertures 41 and 43, respectively, of substrate 20
to exit substrate 20 at first major surface 22 thereof to an exterior in the preassembled
laminate 100. The rigid spacer element 55 is disposed in fourth edge 88 of the
preassembled laminate 100 and spaces substrate 20 apart from superstrate 60 and from PV
5 cells 30. The thickness (not indicated) of rigid spacer element 55 is greater than the
thickness of the PV cells 30 such that rigid spacer element 55 may maintain the front gap
(not shown) between the first major surface (62 in Fig. 4) of the superstrate 60 and the
second major surface 38 of the PV cells 30 and the rear gap (not indicated) between the first
major surface 32 of the PV cells 30 and the second major surface 28 (Fig. 2) of the substrate
10 20 when the preassembled laminate 100 is oriented with the fourth edge 88 facing up (as
shown later in Fig. 5). The first and second major surfaces 32 and 38 of the PV cells 30 are
in fluid communication with an exterior (not indicated) of the preassembled laminate 100 via
the fourth edge 88, which is open in Fig. 2.
[0031] Fig. 3 shows the perspective view of another embodiment 110 of the preassembled
15 laminate. In Fig. 3, a preassembled laminate 110 is identical to the preassembled laminate
100 of Fig. 2 except the preassembled laminate 110 lacks the four corner spacer/tie
elements 50 (FIG. 2) of the preassembled laminate 100 of Fig. 2. (Use of the four corner
spacer/tie elements 50 and/or rigid spacer element 55 is optional in the method so long as
the front and rear gaps (not indicated) may be maintained during the introducing step.) In
20 Fig. 3, the superstrate 60 is spaced apart from substrate 20 by the rigid spacer element 55.
The rigid spacer element 55 creates the opening 85 in the fourth edge 88 of the
preassembled laminate 110.
[0032] Fig. 4 shows the partially exploded view of the preassembled laminate 100. In Fig. 4,
the preassembled laminate 100 comprises the substrate 20, the thirty-six PV cells 30,
25 interconnection circuit (plurality (forty) of 40 and five of 49), bus bar connects 42 and 44, and
four corner spacer/tie elements 50 from the partial assembly 10. Together the PV cells 30,
interconnection circuit (40 and 49), bus bar connects 42 and 44 comprise an interconnected
PV cell subassembly (10 in FIG. 1) that is partially exploded (interconnects 40, bus bar
connects 42 and 44, bus bars 49, and tapes 51 are kept together) in FIG. 4. The
30 preassembled laminate 100 also comprises the superstrate 60, three pieces of sealing tape
70, and a rigid spacer element 55. The superstrate 60 has the first major surface 62 and
second major surface 68, which is spaced apart from the first major surface 62 by the
thickness (not indicated) of the superstrate 60. Sealing tape 70 wraps around and seals
edges 82, 84, and 86 of the preassembled laminate 100 as described. The rigid spacer
DC11750NP1
7
element 55 is partially disposed in fourth edge 88 of the preassembled laminate 100. Bus
bar connects 42 and 44 travel from two of bus bars 49 of interconnection circuit (40 and 49)
at second major surface 28 of substrate 20 (interior in the preassembled laminate 100)
through apertures 41 and 43, respectively, of substrate 20 to exit substrate 20 at first major
5 surface 22 thereof to an exterior in the preassembled laminate 100.
[0033] Fig. 5 shows the perspective view of the preassembled laminate 100 during the
introducing step of the method. In Fig. 5, the preassembled laminate 100 (Figs. 2 and 4) is
disposed in a vertical orientation (± 30° of vertical orientation) such that the fourth edge 88 of
the preassembled laminate 100 is oriented up and is open. The first and second major
10 surfaces 32 and 38 of the thirty-six PV cells 30 are in fluid communication with an exterior
(not indicated) of the preassembled laminate 100 via the fourth edge 88. An effective amount
of a liquid encapsulant 90 (e.g., a liquid polyorganosiloxane encapsulant) is being introduced
by pouring same from container 99 into the preassembled laminate 100 via the opening (not
indicated, similar to 85 in Fig. 3)) in the fourth edge 88 of the preassembled laminate 100. At
15 the point in time shown in Fig. 5, the liquid encapsulant 90 has reached height 92, which is
slightly greater than 50% of the total height, h, of the preassembled laminate 100. This may
be easily understood by observing the depth of liquid encapsulant 90 relative to the rows of
PV cells 30. The sealing of the edges 82, 84, and 86 of the preassembled laminate 100
prevent the liquid encapsulant 90 from leaking from the preassembled laminate 100. The
20 liquid encapsulant 90 is seen disposed in a front side gap (not indicated) between the first
major surface (62 in Fig. 4) of the superstrate 60 and the second major surface 38 of the PV
cells 30. Although it may be difficult to appreciate in Fig. 5, the liquid encapsulant 90 is also
disposed in a rear side gap (not indicated) between the first major surface 32 of the PV cells
30 and the second major surface (see 28 in Fig. 2 and 4) of the substrate 20.
25 [0034] Fig. 6 shows the perspective view of the embodiment of the PV cell module 500
prepared from the preassembled laminate 100. In Fig. 6, the PV cell module 500 has been
prepared by allowing the introduced liquid encapsulant 90 (as in Fig. 5) to coat both first and
second major surfaces 32 and 38 of the thirty-six PV cells 30, and then removing the three
pieces of the sealing tape (not shown, see tapes 70 in Fig. 5) from edges 82, 84 and 86 and
30 removing the rigid spacer element (not shown, see 55 in FIG. 5) from the fourth edge 88 to
give the PV cell module 500. Optionally, the introduced liquid encapsulant 90 may be cured
in the PV cell module 500. If the liquid encapsulant 90 is uncured, the seal (not shown, see
tapes 70 in FIG. 5) left on the PV cell module 500 and a further tape may be applied to edge
88 of the PV cell module 500. If the liquid encapsulant 90 is cured after the allowing step,
DC11750NP1
8
optionally the three pieces of the sealing tape (not shown, see tapes 70 in Fig. 5) may be
removed from the PV cell module 500. Typically, the liquid encapsulant 90 is curable, the
rigid spacer element (not shown, see 55 in FIG. 5) is removed from the fourth edge 88, and
then the PV cell module 500 is laid down in a horizontal orientation, the front and rear
portions of the liquid enc 5 apsulant 90 are leveled, and the liquid encapsulant 90 is cured with
the PV cell module 500 disposed in a horizontal orientation (± 30° of horizontal orientation).
The three pieces of the sealing tape (70 in Fig. 5) may be left in place, alternatively removed
from the edges 82, 84 and 86 prior to the horizontal curing. Alternatively, the introduced
liquid encapsulant 90 is cured in the vertical orientation after removing the rigid spacer
10 element (not shown, see 55 in FIG. 5), but prior to the removing of the three pieces of the
sealing tape (70 in Fig. 5) from edges 82, 84 and 86. The PV cell module 500 sequentially
comprises a front portion (not indicated) of the liquid encapsulant 90, interconnected PV
cells (PV cells 30, interconnection circuit (40 and 49), and bus bar connects 42 and 44), rear
portion (not indicated) of the liquid encapsulant 90, and substrate 20. Alternatively in another
15 embodiment (not shown), the sealing tapes (70 in Fig. 5) may be left in place along edges
82, 84 and 86 and the optional fourth tape (not shown) may be added to edge 88 of the PV
cell module 500, which may then further comprise the sealing tapes (70 in Fig. 5). The liquid
encapsulant 90 may be cured after the allowing step. In addition to encapsulating the PV
cells 30, the liquid encapsulant, before curing and the cured product thereof after curing,
20 may also encapsulate around an interior (to embodiment 500) portion of bus bar connects 42
and 44 where they connect to two of the bus bars 49 of interconnection circuit (40 and 49)
and also plug up or fill in any remaining opening in apertures 41 and 43.
[0035] Fig. 7 shows the perspective view of another embodiment of the preassembled
laminate during the introducing step of the method. In Fig. 7, a preassembled laminate 120
25 is identical to the preassembled laminate 100 of Fig. 5 except instead of the three pieces of
the sealing tape 70 in Fig. 5, the three edges 82, 84, and 86 of preassembled laminate 120
are sealed by strip seal 79. The strip seal 79 is disposed between substrate 20 and
superstrate 60 such that strip seal 79 is in operative sealing contact with the second major
surface (28 in Figs. 1 and 4) of the substrate 20 and with the first major surface (62 in Fig. 4)
30 of the superstrate 60. The preassembled laminate 120 is disposed in a vertical orientation
such that the fourth edge 88 of the preassembled laminate 120 is oriented up and is kept
open by rigid spacer element 55. The first and second major surfaces 32 and 38 of the thirtysix
PV cells 30 are in fluid communication with an exterior (not indicated) of the
preassembled laminate 120 via the fourth edge 88. An effective amount of a liquid
DC11750NP1
9
encapsulant 90 (e.g., a liquid polyorganosiloxane encapsulant) is being introduced by
pouring same from container 99 into the preassembled laminate 120 via the opening (not
indicated, similar to 85 in Fig. 3)) in the fourth edge 88 of the preassembled laminate 120.
[0036] Fig. 8 shows the perspective view of the embodiment of the PV cell module 520
5 prepared from the preassembled laminate 120. In Fig. 8 the PV cell module embodiment 520
is identical to the PV cell module 500 except having been prepared using the three pieces of
the sealing tape 70 used to prepare the PV cell module 500, the three edges 82, 84, and 86
of PV cell module 520 had been, and still are, sealed by strip seal 79 (e.g., a bead of silicone
sealant or a silicone rubber dam). Optionally, the introduced liquid encapsulant 90 may be
10 cured without removing strip seal 79 to give a cured form of PV cell module 520.
[0037] In addition to, or as an alternative to, the sealing tape 70 and strip seal 79 of
preassembled laminates 100, 110 and 120, the three edges 82, 84, and 86 (Figs. 2 to 8)
may be sealed with a viscous adhesive or sealant composition, gasket, O-ring, exterior
frame, or other mechanical sealing means.
15 [0038] Fig. 9 is the perspective view of an alternate embodiment of a partial assembly to the
preassembled laminate. In Fig. 9, the partial assembly 8 is identical to the prior partial
assembly (10 of Fig. 1) except partial assembly 8 has substrate 21, which lacks apertures
(i.e., lacks apertures 41 and 43 of partial assembly 10 of Fig. 1). The partial assembly 8
comprises a substrate 21, thirty-six PV cells 30, interconnection circuit comprising five
20 horizontally disposed bus bars 49, a plurality of vertically disposed interconnects 40, Bus bar
connects 42 and 44, and four corner spacer/tie elements 50. Together the PV cells 30,
interconnection circuit (40 and 49), bus bar connects 42 and 44 comprise an interconnected
PV cells subassembly (not indicated). The substrate 21 has a first major surface 22 and a
second major surface 28, which is spaced apart from the first major surface 22 by the
25 thickness (not indicated) of the substrate 21.
[0039] Fig. 10 is the perspective view of another embodiment of the preassembled laminate.
In Fig. 10, the preassembled laminate 130 is identical to preassembled laminate 110 except
preassembled laminate 130 lacks apertures in substrate 21 (i.e., lacks apertures 41 and 43
of Fig. 3). In Fig. 10, the thickness (not indicated) of the PV cells 30 and front and rear gaps
30 (not indicated) is slightly greater than thickness of the bus bar connects 42 and 44. Bus bar
connects 42 and 44 travel from two of bus bars 49 of interconnection circuit (40 and 49)
between the first major surface 62 of superstrate 60 and the second major surface 28 of
substrate 21 through aperture(s) (not visible) in the sealing tape 70 at edge 86 of the
DC11750NP1
10
preassembled laminate 130. Rigid spacer element 55 spaces substrate 21 and superstrate
60 apart from each other and PV cells 30.
[0040] Fig. 11 is the perspective view of the embodiment of the PV cell module 530
prepared from the prior preassembled laminate (130 of FIG. 10). In Fig. 11, the PV cell
5 module 530 has been prepared by allowing the introduced liquid encapsulant 90 (introduced
in a manner similar to that described for Fig. 6) to coat both first and second major surfaces
32 and 38 of the thirty-six PV cells 30, and then removing the three pieces of the sealing
tape (70 in Fig. 10) from edges 82, 84 and 86 and removing the rigid spacer element (55 in
Fig. 10) from the fourth edge 88 (Fig. 10) to give the PV cell module 530. Optionally, the
10 introduced liquid encapsulant 90 may be cured prior to, alternatively after, the removing of
the three pieces of the sealing tape (70 in Fig. 10) to give a cured form of PV cell module
530.
[0041] Another alternative embodiment, not drawn, is identical to preassembled laminate
130 of FIG. 10 and PV cell module embodiment 530 of FIG. 11 except instead of the three
15 pieces of the sealing tape (70 in Fig. 10), the edges (82, 84, and 86 in FIG. 10) are sealed by
a strip seal in a manner similar to use of the strip seal 79 in Figs. 7 and 8.
[0042] The invention may be a method (aspect 1) of manufacturing a PV cell module (500,
520, or 530) from a preassembled laminate (100, 110, 120, or 130) comprising a superstrate
(60), interconnected PV cells in need of encapsulation (30), interconnection circuit (40 and
20 49), bus bar connects (42, and 44), a substrate (20 or 21) spaced apart from the superstrate
(60) so as to define a volumetric space housing the PV cells (30) and a front gap (not
indicated) between the superstrate (60) and the PV cells (30) and a rear gap (not indicated)
between the PV cells (30) and the substrate (20 or 21), and a seal (70 or 79) that operatively
seals at least one first edge (82, 84, and 86) of the preassembled laminate (100, 110, 120,
25 or 130)) against leakage of a liquid encapsulant (90) from the volumetric space and wherein
the preassembled laminate (100, 110, 120, or 130)) defines a second edge (88) having an
opening (85) for allowing a liquid encapsulant (90) to flow from a source thereof (99) that is
exterior to the preassembled laminate (100, 110, 120, or 130) through the opening (85) in
the second edge (88) and into the front and rear gaps (not indicated), the method comprising
30 introducing an effective amount of a liquid encapsulant (90) through the opening (85) in the
second edge (88) of the preassembled laminate (100, 110, 120, or 130) into the front and
rear gaps (not indicated) of the preassembled laminate (100, 110, 120, or 130) and allowing
the introduced liquid encapsulant (90) to fill the front gap between the superstrate (60) and
PV cells (30) and fill the rear gap between the PV cells (30) and the substrate (20 or 21) so
DC11750NP1
11
as to encapsulate the PV cells (30) to give a first PV cell module (500, 520, or 530)
sequentially comprising the substrate (20 or 21), front portion of the liquid encapsulant (90),
interconnected PV cells (30), interconnection circuit (40 and 49), bus bar connects (42 and
44), rear portion of the liquid encapsulant (90), and substrate (20 or 21), and also comprising
5 the seal (70 or 79), which optionally may be removed in another step.
[0043] During the introducing step the first edge(s) (82, 84, and 86) of the preassembled
laminate (100, 110, 120, or 130) typically is side and bottom edges of the preassembled
laminate (100, 110, 120, or 130) and the second edge (88) of the preassembled laminate
(100, 110, 120, or 130) typically is a top edge thereof such that the opening (85) in the
10 second edge (88) faces upward.
[0044] The front portion and rear portion of the liquid encapsulant (90) are introduced into
the preassembled laminate (100, 110, 120, or 130) by the introducing step. The first edge(s)
(82, 84, and 86) of the preassembled laminate (100, 110, 120, or 130) that is sealed with the
seal (70 or 79) may be greater than 50% but less than 100% of the length of the entire
15 periphery of the preassembled laminate (100, 110, 120, or 130). Typically the sealed first
edge(s) (82, 84, and 86) is at least 60%, alternatively at least 75%, alternatively at least 90%
of the length of the entire periphery (82, 84, 86, and 88) of the preassembled laminate (100,
110, 120, or 130). When the preassembled laminate (100, 110, 120, or 130) is in the profile
of a square or rectangle, the sealed first edge(s) (82, 84, and 86) is three of the sides of the
20 square or rectangle. Optionally, a portion of the fourth side (88) of the square or rectangular
preassembled laminate (100, 110, 120, or 130) may be sealed except for an opening (85)
that provides a conduit for introducing the liquid encapsulant (90). A portion of the opening
(85) that provides the conduit for introducing the liquid encapsulant (90) into the
preassembled laminate (100, 110, 120, or 130) typically remains open during the introducing
25 step so as to provide a conduit for air to be released from the preassembled laminate (100,
110, 120, or 130) during the introducing step. Alternatively, the entire portion of the opening
(85) may be blocked by the liquid encapsulant (90) during some of the introducing step, in
which embodiment a small vent or vent tube (not shown) may be included (temporarily) in
the sealed first edge(s) (82 and/or 86) proximal to the fourth side (88), or typically in the
30 fourth side (88), to provide a conduit for air to be released from the preassembled laminate
(100, 110, 120, or 130) during the introducing step. The vent may be plugged up or filled in
by cured product of curing the liquid encapsulant (90) or by a seal or the vent tube, as the
case may be, may be removed and any remaining hole plugged up or filled in..
DC11750NP1
12
[0045] The method comprises the step of introducing the effective amount of a liquid
encapsulant (90) into the gap (85) of the preassembled laminate (100, 110, 120, or 130).
This introducing step is counterintuitive in that the preassembled laminate (100, 110, 120, or
130) is built by adding the liquid encapsulant (90) between the superstrate (60) and PV cells
5 (30) and between the PV cells (30) and the substrate (20 or 21) after the superstrate (60),
PV cells (30) and substrate (20 or 21) have already been positioned relative to each other
and assembled in the preassembled laminate (100, 110, 120, or 130). This introducing step
is also counterintuitive in that after the allowing step the PV cells (30) are coated with the
liquid encapsulant (90) while they are sandwiched between the superstrate (60) and the
10 substrate (20 or 21). (The horizontal orientation build method of the prior art could not be
adapted to add the liquid encapsulant after the second one of the superstrate and substrate
has been laid down.) If desired, the front and rear gaps (not indicated) may be maintained
by placing a rigid spacer element (55) between the superstrate (60) and the substrate (20 or
21) near (85) where the effective amount of the liquid encapsulant (90) is entering the
15 preassembled laminate (100, 110, 120, or 130). The rigid spacer element (55) may be
removed after the introducing step to enhance the allowing step.
[0046] In the introducing step, the preassembled laminate (100, 110, 120, or 130) may be
oriented with open edge (88) facing up such that the preassembled laminate (100, 110, 120,
or 130) is within plus or minus (±) 30° of vertical orientation (i.e., from - 30° to + 30° on z20
axis), alternatively within ± 20° of vertical orientation, alternatively within ± 10° of vertical
orientation, alternatively within ± 5° of vertical orientation, alternatively within ± 1° of vertical
orientation. At vertical orientation, the preassembled laminate (100, 110, 120, or 130) is
disposed parallel to a z-axis and 90.0° or perpendicular to an x-axis and y-axis or horizontal
plane in an x-y Cartesian coordinate.system wherein z-axis indicates height, x-axis indicates
25 width, and y-axis indicates depth. The angle for measuring the ± 30° of vertical orientation is
measured relative to first major surface 22 of substrate 20 or second major surface 68 of
superstrate 60 relative to the horizontal x-y plane. The liquid encapsulant (90) may be
introduced under influence of gravity at ambient pressure (e.g., 97 to 107 kPa) when open
edge (88) is facing up. Alternatively instead of, or additionally in addition to, gravity in the
30 introducing step, the liquid encapsulant may be introduced into the preassembled laminate
under a pressure greater than ambient pressure, e.g., pressure from 110 kPa to 200 kPa.
[0047] Alternatively in the introducing step, the preassembled laminate (100, 110, 120, or
130) may be oriented with open edge (88) facing sideways such that the preassembled
laminate (100, 110, 120, or 130) is within plus (+) 30° of horizontal orientation (i.e., from 0° to
DC11750NP1
13
+ 30° of x-y plane), alternatively within + 20° of horizontal orientation, alternatively within +
10° of horizontal orientation, alternatively within + 5° of horizontal orientation, alternatively
within + 1° of horizontal orientation. At horizontal orientation, the preassembled laminate
(100, 110, 120, or 130) is disposed parallel to the x-y plane. The liquid encapsulant (90) may
5 be flowed under the greater than ambient pressure into the opening (85) in the open edge
(88) and into the preassembled laminate (100, 110, 120, or 130) at horizontal orientation.
[0048] The effective amount of the liquid encapsulant (90) is equal to, and typically greater
than a sum of the amounts of the front and rear portions of the liquid encapsulant (90) in the
front and rear gaps of the PV cell module (500, 520, or 530). The effective amount of the
10 liquid encapsulant (90) may be based on weight thereof. Typically, however, the effective
amount of the liquid encapsulant (90) is based on a visual observation of reaching a fill level
within the preassembled laminate (100, 110, 120, or 130). The fill level may be a quantity
sufficient to fill the vertically-oriented the preassembled laminate (100, 110, 120, or 130) to a
height of from 60 to 90 percent (%), alternatively 65% to 85%, alternatively 70% to 80% of
15 the total height (h) of the preassembled laminate (100, 110, 120, or 130) in the vertical
orientation. While the fill level of the liquid encapsulant (90) may be up to 100% of the total
height (h) of the preassembled laminate (100, 110, 120, or 130) in the vertical orientation,
generally this may disadvantageously result in excess liquid encapsulant being squeezed
out of the preassembled laminate (100, 110, 120, or 130) during the subsequent allowing
20 step, thereby undesirably wasting some of the liquid encapsulant (90). The fill level of the
liquid encapsulant may be less than 60% of the total height (h) of the preassembled laminate
(100, 110, 120, or 130) in the vertical orientation so long as the quantity of the liquid
encapsulant (90) is sufficient to coat the front and rear major surfaces (32 and 38), typically
all surface of the PV cells (30) during the subsequent allowing step. If desired, the fill level of
25 the liquid encapsulant (90) in the preassembled laminate (100, 110, 120, or 130) before the
allowing step may be adjusted.
[0049] The method also comprises the step of allowing the introduced liquid encapsulant
(90) to coat the PV cells (30) and fill the gap between the superstrate (60) and PV cells (30)
and fill the gap between the PV cells (30) and the substrate (20 or 21) to give the PV cell
30 module (500, 520, or 530). Typically, once the effective amount of the liquid encapsulant
(90) has been added (e.g., poured) into the preassembled laminate (100, 110, 120, or 130),
the rigid spacer element (55), if any, is removed, the superstrate (60) and the substrate (20
or 21) of the preassembled laminate (100, 110, 120, or 130), now containing the liquid
encapsulant (90) in the front and rear gaps, are adjusted so as to cause the liquid
DC11750NP1
14
encapsulant (90) spread in the front and rear gaps and completely cover or encapsulate the
interconnected PV cells (30) and interconnection circuit (40 and 49) to give the PV cell
module (500, 520, or 530). After the rigid spacer element (55) has been removed, the PV
cell module (500, 520, or 530) may be laid horizontally for the allowing step. If desired, the
5 superstrate (60) and the substrate (20 or 21) of the resulting PV cell module (500, 520, or
530) may be held in position relative to each other and the interconnected PV cells (30) and
interconnection circuit (40 and 49) by applying opposing mechanical forces to the external
surface (68) of the superstrate (60) and the external surface (22) of the substrate (20 or 21).
For example, the holding in position may be accomplished by a human being or clamps
10 holding the PV cell module (500, 520, or 530) together for a period of time, e.g., a period of
time sufficient to allow curing of the liquid encapsulant (90).
[0050] The method may further comprise a preliminary step of assembling the
preassembled laminate (100, 110, 120, or 130) from a partial assembly (10, 8) as described.
[0051] The method may be used to manufacture any size PV cell module (500, 520, or 530),
15 wherein the size of the PV cell module (500, 520, or 530) may expressed in performance
terms as the maximum number of watts (W) of electricity it is designed to produce. The
method may be practiced by indigenous peoples in rural environments, including by poorly
educated inhabitants in locations without access to an electricity grid. When the size PV cell
module (500, 520, or 530) is relatively small (e.g., from 1 W to 100 W, alternatively from 10
20 W to 100 W, alternatively from 2 W to 50 W, alternatively from 5 W to 25 W, e.g., a 10 W, 20
W, 50 W, or 80 W PV cell module), the introducing and allowing steps, and the optional
curing step of the method may be fully manual and may be performed without using any
equipment or machinery such as a V-P-C machine.
[0052] The present invention further includes the kit with components and instructions for
25 assembling the PV cell module (500, 520, or 530). The components of the kit may comprise
the superstrate (60), PV cells (30), interconnection components (e.g., tabbing, bus bars,
electrically conductive paste, solder flux, or a combination thereof for interconnection circuit
(40 and 49) and bus bar connects (42 and 44), substrate (20 or 21), liquid encapsulant (90),
and container (99) for the liquid encapsulant (90). The components may further comprise
30 spacing elements and sealing elements that are useful for assembling the PV cell module
(500, 520, or 530) according to the method, the spacing elements comprising optional corner
spacer/tie elements (50) and rigid spacer element (55), and the sealing elements comprising
the seal (70 and/or 79). The components may further comprise any other components of a
PV cell module such as an optional tie layer material (e.g., adhesion promoter), pottant
DC11750NP1
15
material (for a junction box), and/or a junction box (not shown) and/or an inverter (not
shown) for the PV cell module (500, 520, or 530). The instructions may include directions for
assembling the partial assembly (10 or 8) and/or the preassembled laminate (100, 110, 120,
or 130) and directions for manufacturing the PV cell module (500, 520, or 530) therefrom
according to the method. The instructions 5 may further include directions for placing one or
more of the PV cell modules (500, 520, or 530) in a location and orientation suitable for
receiving sunlight (e.g., on a rooftop and angled for orienting solar panels towards the sun)
and instructions for electrically connecting the PV cell module (500, 520, or 530) to the
junction box, inverter, an electricity grid or an electrical device (e.g., light bulb, electrical
10 charging device, electric fan or cooking stove) in need of electricity. When the size PV cell
module (500, 520, or 530) is relatively small the kit may be manually handled by the
indigenous peoples for use in the all manual embodiment of the method.
[0053] The superstrate (60) is transparent and useful for PV applications. It allows
transmission of light therethrough and functioning as a barrier layer between an environment
15 in which the PV cell module (500, 520, or 530) may be used (e.g., outdoor environment) and
the front portion of the liquid encapsulant (90). The superstrate (60) may be characterizable
by a light transmittance of at least 70 percent as determined by UV/Vis spectrophotometry
using ASTM E424-71 (2007). The superstrate (60) is effective for allowing transmission of
sunlight therethrough. The superstrate (60) may be a silicate glass, e.g., a soda-lime or
20 borosilicate glass, or may be a transparent organic polymer, e.g., polycarbonate.
[0054] The substrate (20 or 21) is useful for PV applications by, among other things,
supporting the PV cells (30) and functioning as a barrier layer between an environment in
which the PV cell module (500, 520, or 530) may be used (e.g., outdoor environment) and
the rear portion of the liquid encapsulant (90). The substrate (20 or 21) may be also called a
25 back sheet. The substrate (20) may define one or more apertures (41 and 43) therethrough
that may serve as conduit(s) for bus bar connects (42 and 44). If desired, a seal such as a
piece of tape or a plug of elastomer (not shown) may be applied to substrate 20 to cover
aperture(s) (41 and 43) (e.g., tape applied over apertures 41 and 43 on first major surface
22) to prevent leakage of liquid encapsulant therethrough during the introducing step of the
30 method. The substrate (20 or 21) may be a silicate glass such as a soda-lime or borosilicate
glass. Alternatively, substrate (20 or 21) may be a polyorganosiloxane; an organic polymer;
or a blend thereof. The organic polymer may comprise, alternatively consist essentially of,
alternatively consist of a polyolefin (e.g., a polyethylene or polypropylene), a poly(ethylene
terephthalate), a poly(ethylene naphthalate), a poly(vinyl fluoride) (e.g., TEDLAR, du Pont,
DC11750NP1
16
Wilmington, Delaware), a poly(ethylene vinyl acetate), and/or any other organic polymer.
The substrate (20 or 21) may be free of all polymers that are not polyorganosiloxanes,
alternatively free of all polymers that are not organic polymers, alternatively free of all
polymers that are not organic polymers or polyorganosiloxanes or hybrids or copolymers or
5 blends thereof.
[0055] The substrate (20 or 21) and superstrate (60) typically independently have a
thickness of from 0.03 millimeter (mm) to 5 mm, alternatively from 0.1 to 4 mm, alternatively
from 0.3 to 3.8 mm, alternatively from 1.3 to 3.6 mm, (e.g., 3.2 mm). The substrate (20 or 21)
and superstrate (60) typically have the same length and width. The substrate (20 or 21) and
10 superstrate (60) may have a length and width of from 5 centimeters to 2 meters, alternatively
from 10 cm to 150 cm, alternatively from 20 cm to 130 cm (e.g., 20 cm square, alternatively
20 cm by 30 cm, alternatively 50 cm by 130 cm). The substrate (20 or 21) and superstrate
(60) may be a geometric shape such as a square, rectangle, oval, circle, trapezoid, or other
geometric shape, or an irregular shape. The substrate (20 or 21) and superstrate (60) are
15 not limited to those dimensions or shapes. When the substrate (20 or 21) and superstrate
(60) have four sides, the preassembled laminate comprising same typically has three sealed
edges (82, 84, and 86) and one unsealed edge (88). In practice however, the preassembled
laminate (100, 110, 120, or 130) may have three sealed sides (82, 84, and 86) and a fourth
side (88) that is sealed except for a port for introducing the liquid encapsulant (90). The
20 substrate (20 or 21) may be tacky or non-tacky and may be a gel, gum, or solid.
[0056] The PV cells (30) may be operatively attached directly or indirectly to either the
substrate (20 or 21) or the superstrate (60) prior to the introducing step. For example, the
interconnection circuit (40 and 49) may be operatively attached to the second major surface
(28) of the substrate (20 or 21), and the PV cells (30) may be operatively attached to the
25 interconnection circuit (40 and 49) such that the PV cells are indirectly operatively attached
to the second major surface (28) of the substrate (20 or 21). Alternatively or additionally, the
PV cells (30) may be operatively attached directly to the second major surface (28) of the
substrate (20 or 21). Each of the direct and indirect operative attachments is effective for
holding the PV cells (30) in place during the introducing and allowing steps of the method.
30 [0057] The composition of the PV cells (30) is not particularly limited. The composition may
be based on silicon, silicon carbide, cadmium telluride, copper indium/gallium
selenide/sulfide, gallium arsenide, polyphenylene vinylene, copper phthalocyanine, carbon
fullerenes, and combinations thereof. For example, the composition of the PV cells (30) may
be amorphous silicon, monocrystalline silicon, multicrystalline silicon, microcrystalline silicon,
DC11750NP1
17
or nanocrystalline silicon. Alternatively, the composition of the PV cells (30) may be silicon
carbide. Alternatively, the composition of the PV cells (30) may be cadmium telluride,
alternatively copper indium/gallium selenide/sulfide (e.g., CIGS), alternatively gallium
arsenide, alternatively poly(para-phenylene vinylene), alternatively copper phthalocyanine,
alternatively carbon fullerenes, altern 5 atively the combinations thereof. The PV cells (30) may
be in the form of ingots, ribbons, thin films, and/or wafers. The PV cells (30) may also
include light absorbing dyes such as ruthenium organometallic dyes. Most typically, the PV
cells (30) are monocrystalline and/or multicrystalline silicon.
[0058] A plurality of PV cells (30) are used. There are at least two, alternatively at least 10,
10 alternatively at least 30, and typically no more than 100, PV cells (30). The PV cells (30) may
have a thickness of from 50 to 250 micrometers (μm), alternatively from 100 to 225 μm,
alternatively from 175 to 225 μm. The PV cells (30) may independently have a length and
width of 50 to 300 millimeters (mm) each such as 125 mm, 156 mm, or 224 mm each. The
PV cells (30) may be square shaped, alternatively rectangular shaped. The PV cells (30) are
15 not limited to these dimensions.
[0059] The PV cells (30) are electrically interconnected such as by an interconnection circuit
(40 and 49), which is connected via bus bar connects (42 and 44) to a junction box, electrical
grid, battery, or other electrical equipment. The interconnection circuit typically comprises
bus bars (49), Interconnects (40), and electrically conductive adhesive, e.g., based on
20 copper or silver. The components of the interconnection circuit (40 and 49) may be applied
before placing the PV cells (30) on the substrate (20 or 21).
[0060] The liquid encapsulant (90) may be non-curable, alternatively curable. When the
liquid encapsulant (90) is uncurable or curable but uncured, typically the seal may not be
removed from the PV cell module (500, 520, or 530). Typically, however, the liquid
25 encapsulant (90) is curable to the cured encapsulant. When the liquid encapsulant (90) is
curable, it may be an ambient temperature curable material such as a substance that can
cure at a temperature of from 30° C. to 45° C. Typically the liquid encapsulant (90) is
curable, and the curable liquid encapsulant is cured in situ after the allowing step of the
method to give the cured encapsulant. The curing may be performed in ambient conditions
30 such as where the PV cell module (500, 520, or 530) is being used to generate electricity,
alternatively the curing may be performed in an oven set to a temperature of from 50° C. to
200° C. (e.g., 120° C. to 150° C.) to give the PV cell module (500, 520, or 530) with cured
front portion and cured rear portion of the encapsulant.
DC11750NP1
18
[0061] The composition of the liquid encapsulant (90) is not particularly important. The
composition of the curable liquid encapsulant may be a curable organic polymer, or oligomer
precursor or monomer(s) precursor thereof; alternatively a curable organosiloxane polymer,
oligomer precursor or monomer(s) precursor thereof. For example, the liquid encapsulant
(90) may be a curable 5 polyorganosiloxane (polymer) such as a hydrosilylation-curable
polyorganosiloxane composition, condensation-curable polyorganosiloxane composition, or
free radical-curable polyorganosiloxane composition. The free radical-curable
polyorganosiloxane composition may be a radiation-curable polyorganosiloxane
composition, a light-curable polyorganosiloxane composition (e.g. UV light-curable), or a
10 peroxide-curable polyorganosiloxane composition. Typically, the liquid encapsulant (90) is
the hydrosilylation-curable polyorganosiloxane. Examples of suitable hydrosilylation-curable
polyorganosiloxane compositions are described in US 2011/0203664 A1 or US
2006/0207646 A1, such as for example in paragraphs [0023 to 0037; and 0048] of US
2006/0207646 A1. A typical hydrosilylation-curable polyorganosiloxane composition
15 comprises a vinyl-terminated polydimethylsiloxane, a Si-H functional polydimethylsiloxane
(i.e., a dimethyl, methylhydrogen polysiloxane), and a platinum catalyst. The vinyl-terminated
polydimethylsiloxane typically has on average per molecule at least 1.0, alternatively at least
2.0, alternatively up to 5 vinyl-groups. The Si-H functional polydimethylsiloxane typically
contains on average per molecule at least 1.0, alternatively at least 2.0, alternatively up to 5
20 Si-H functional groups and may function as a crosslinker. The Pt catalyst may be a complex
of chloroplatinic acid and certain vinyl-containing organosiloxanes as described in US
3,419,593 such as the reaction product of chloroplatinic acid and l,3-diethenyl-l,l,3,3-
tetramethyldisiloxane. The hydrosilylation catalyst may be unsupported or disposed on a
solid support (e.g., carbon, silica, or alumina). The hydrosilylation catalyst may be a Pt25
ligand complex that is microencapsulated in a thermoplastic resin shell as described in US
4,766,176 and US 5,017,654 for increased stability during storage of the hydrosilylationcurable
organosiloxane before curing. When curing is desired, heating melts the shell and
releases the Pt catalyst therefrom. Instead of Pt catalyst, alternatively the catalyst may be
rhodium, ruthenium, palladium, osmium, or iridium, or any combination of at least two
30 thereof. The hydrosilylation-curable polyorganosiloxane composition may further comprise
an organosiloxane adhesion promoter.
[0062] The liquid encapsulant (90) is a “liquid” in so far as it is a flowable material at 25° C.
and 101 kilopascals pressure. The liquid encapsulant (90) prior to curing may have a
viscosity of from 150 to 60,000 centipoise (cps). The viscosity of the liquid encapsulant (90)

may be from 200 to 15,000 cps, alternatively from 200 to 5,000 cps, alternatively from 200 to
1,000 cps, alternatively from 200 to 500 cps, e.g., from 240 to 480 cps. The foregoing
viscosity is measured according to ASTM D4287-00(2010) (Standard Test Method for High-
Shear Viscosity Using a Cone/Plate Viscometer) at 25° C. After curing, the cured
5 encapsulant may be a gel or thermoset.
[0063] The spacer/tie element may function only as a spacer, only as a tie element (e.g., a
thin adhesive tie layer), or as both a spacer and tie element (50).
[0064] One or more adhesion promoters may be used in the PV cell module (500, 520, or
530) to enhance adhesion of the cured encapsulant to the superstrate (60) and/or substrate
10 (20 or 21) and/or PV cells (30). Examples of suitable adhesion promoters are described in
US 2006/0207646 A1, such as for example in paragraphs [0038 to 0043].
[0065] The polyorganosiloxane composition may be prepared as a one part or multiple part
composition. The one-part composition may be prepared by combining all ingredients by any
convenient means, such as mixing. All mixing steps or just a final mixing step may be
15 performed under conditions that minimize or avoid heating (e.g., maintain temperature below
30° C during mixing). For example, a multiple part (e.g., 2 part) hydrosilylation curable
composition may be prepared where at least a primary polyorganosiloxane (e.g., an alkenylfunctional
polydiorganosiloxane such as a vinyl-terminated polydimethylsiloxane), and
optionally any other organosilicon compound (e.g., an adhesion promoter and/or chain
20 extender/crosslinker such as the organohydrogensilicon compound), is stored in one part
(Part A), and any catalyst is stored in a separate part (Part B), and the parts A and B are
combined (e.g., by mixing) shortly before use of the composition. Typically the chain
extender/crosslinker and the catalyst are stored in separate parts when the catalyst is
catalytically active (not microencapsulated or not inhibited). The catalyst Part B may further
25 comprise the alkenyl-functional polydiorganosiloxane.
[0066] Determining numerical property values: for purposes of the present invention and
unless indicated otherwise, the numerical property values used herein may be determined
by the following procedures.
[0067] Determining boiling point: measure boiling point by distillation at standard
30 atmospheric pressure of 101.3 kilopascals (kPa).
[0068] Determining dynamic viscosity: for purposes of the present invention examples and
unless indicated otherwise, use dynamic viscosity that is measured at 25° C. using a
rotational viscometer such as a Brookfield Synchro-lectric viscometer or a Wells-Brookfield
Cone/Plate viscometer. The results are generally reported in centipoise. This method is
DC11750NP1
20
based on according to ASTM D1084-08 (Standard Test Methods for Viscosity of Adhesives)
Method B for cup/spindle and ASTM D4287-00(2010) (Standard Test Method for High-Shear
Viscosity Using a Cone/Plate Viscometer) for cone/plate.
[0069] Determining kinematic viscosity: use test method ASTM-D445-11a (Standard Test
5 Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of
Dynamic Viscosity)) at 25° C. Expressed in cSt or mm2/s units.
[0070] Determining state of matter: Characterize state of matter as solid, liquid, or gas/vapor
at 20° C and a pressure of 101.3 kPa.
[0071] Determining weight percent (wt%): base weight percent of an ingredient of a
10 composition, mixture, or the like on weights of ingredients added to prepare, and total weight
of, the composition, mixture, or the like.
[0072] Materials used in the Invention Examples:
[0073] Liquid encapsulant (90) was Composition LE1. Composition LE1 comprised a
hydrosilylation-curable polyorganosiloxane composition that was prepared by mixing a 1:1
15 w/w ratio of Parts A and B together just prior to the introducing step. Part A is a colorless
liquid comprising > 60 wt% of a dimethylvinyl-terminated polydimethylsiloxane (CAS No.
68083-19-2) and 1.0 to 5.0 wt% of an organosilane. Part A had a specific gravity of 0.97 at
25° C. (relative to water), dynamic viscosity was 430 to 440 millipascal-seconds (mPa-s),
and boiling point was > 65° C. Part B is a colorless liquid comprising > 60 wt% of a
20 dimethylvinyl-terminated polydimethylsiloxane (CAS No. 68083-19-2), 15.0 to 40.0 wt%
hydrogen-terminated polydimethylsiloxane (CAS No. 70900-21-9) and 1.0 to 5.0 wt%
dimethyl, methylhydrogen polysiloxane (CAS No. 68037-59-2). Part B had a specific gravity
of 1.01 at 25° C. (relative to water), dynamic viscosity was 280 mPa-s, and boiling point was
> 65° C. The composition further comprised a microencapsulated platinum catalyst in the
25 form of shell-core particles that contained 0.008 wt% Pt, wherein the shell was a cured vinylterminated
polydimethylsiloxane and the core comprised a platinum-ligand complex.
[0074] Substrate (20) was a square-shaped silicate glass sheet defining two apertures
therethrough proximal to an edge and spaced apart from each other by 2.54 cm. The
substrate (20) was 3.2 mm thick.
30 [0075] Superstrate (60) was a square-shaped silicate glass sheet lacking apertures and
having length and width the same as the length and wide of the silicate glass substrate. The
superstrate (60) was 3.2 mm thick.
[0076] The PV cells (30) were based on multicrystalline silicon.
DC11750NP1
21
[0077] The interconnection circuit (40 and 49) was based on Cu alloy and Al alloy,
respectively, and was operatively connected at ends thereof to proximal ends of two bus bar
connects (42 and 44).
[0078] The invention is further illustrated by, and an invention embodiment may include any
combinations 5 of features and limitations of, the non-limiting examples thereof that follow. The
concentrations of ingredients in the compositions/formulations of the examples are
determined from the weights of ingredients added unless noted otherwise.
[0079] Example (Ex.) 1: production of an uncured PV cell module: Laid down the silicate
glass substrate with its second major surface facing upward, and fixed the 4 by 9 array of
10 interconnected multicrystalline silicon PV cells to the second major surface of the silicate
glass substrate using five pieces of tape placed at different locations over the
interconnection circuit thereof. Fed the distal ends of the two bus bar connects of the
interconnection circuit through different ones of the apertures of the silicate glass substrate
such that the distal ends of the bus bar connects had exited the first major surface of the
15 silicate glass substrate. Sealed the apertures of the silicate glass substrate with a piece of
tape. Placed four corner pieces of double-sided tape on the corners of the second major
surface of the silicate glass substrate to give a partial assembly as shown in Fig. 1. Placed
the silicate glass superstrate over the partial assembly such that the four corners of the first
major surface of the silicate glass superstrate were in contact with the four corner pieces of
20 the double sided tape of the partial assembly, and sealed three edges of the silicate glass
superstrate to the corresponding three edges of the silicate glass substrate with sealing tape
to give a preassembled laminate (e.g., 100 as shown in Fig. 2). Stood the preassembled
laminate upright so that the remaining unsealed edge was on top, and inserted therein a
rigid spacer element therein to maintain an opening between the silicate glass substrate and
25 superstrate that was slightly wider than the thickness of the PV cells. Mixed the component
parts of the liquid encapsulant LE1 together, and immediately poured the resulting liquid
encapsulant LE1 through the opening in the unsealed edge until the preassembled laminate
was filled with the liquid encapsulant LE1 to a height of about 75% of the total height of the
preassembled laminate. When that level was reached, stopped the pouring, removed the
30 rigid spacer element, and manipulated the resulting filled preassembled laminated to allow
the liquid encapsulant LE1 to coat the first and second major surfaces of the PV cells and
the interconnection circuit to give the uncured PV cell module of Ex. 1 sequentially
comprising a silicate glass superstrate, a front portion of the liquid encapsulant LE1, a 4 by 9
DC11750NP1
22
array of interconnected multicrystalline silicon PV cells, a rear portion of the liquid
encapsulant LE1, a silicate glass substrate, and four corner pieces of double-sided tape.
[0080] Ex. 2: production of a cured PV cell module: placed the uncured PV cell module of
Ex. 1 in a 100° C. oven for from 1 to 5 minutes and cured the liquid encapsulant LE1 to give
the cured P 5 V cell module of Ex. 2 sequentially comprising a silicate glass superstrate, a front
portion of a cured polydiorganosiloxane encapsulant, a 4 by 9 array of interconnected
multicrystalline silicon PV cells, a rear portion of the cured polydiorganosiloxane, a silicate
glass substrate, and four corner pieces of double-sided tape.
[0081] Ex. 3 (prophetic): production of a cured PV cell module: place the uncured PV cell
10 module of Ex. 1 outside in direct sunlight at an ambient temperature of 30° to 40° C. for from
1 to 12 hours to give to cure the liquid encapsulant LE1 to give the cured PV cell module of
Ex. 3 sequentially comprising a silicate glass superstrate, a front portion of a cured
polydiorganosiloxane encapsulant, a 4 by 9 array of interconnected multicrystalline silicon
PV cells, a rear portion of the cured polydiorganosiloxane, a silicate glass substrate, and four
15 corner pieces of double-sided tape
[0082] As used herein, “may” confers a choice, not an imperative. “Optionally” means is
absent, alternatively is present. “Contacting” means bringing into physical contact.
“Operative contact” comprises functionally effective touching, e.g., as for modifying, coating,
adhering, sealing, or filling. The operative contact may be direct physical touching,
20 alternatively indirect touching. All U.S. patent application publications and patents referenced
herein, or a portion thereof if only the portion is referenced, are hereby incorporated herein
by reference to the extent that incorporated subject matter does not conflict with the present
description, which would control in any such conflict. All “wt%” (weight percent) are, unless
otherwise noted, based on total weight of all ingredients used to make the composition,
25 which adds up to 100 wt%. Any Markush group comprising a genus and subgenus therein
includes the subgenus in the genus, e.g., in “R is hydrocarbyl or alkenyl,” R may be alkenyl,
alternatively R may be hydrocarbyl, which includes, among other subgenuses, alkenyl. The
“x-direction” and “y-direction” respectively refer to horizontal and vertical axes of a Cartesian
coordinate system.
30 [0083] Embodiments of the invention also include the following numbered aspects.
[0084] 2. The method of aspect 1, wherein during the introducing step the preassembled
laminate is inclined within plus-or-minus 30 degrees of vertical orientation such that the
opening in the second edge of the preassembled laminate is facing upward within plus-orminus
30 degrees of vertical orientation.
DC11750NP1
23
[0085] 3. The method of aspect 2, wherein the introducing step comprises pouring the liquid
encapsulant from a container through the opening in the second edge of the preassembled
laminate onto an upper portion of the photovoltaic cells and the allowing step comprises
allowing the introduced liquid encapsulant to coat the photovoltaic cells and fill the front gap
5 between the photovoltaic cells and the superstrate and the rear gap between the
photovoltaic cells and the substrate of the preassembled laminate, thereby coating the
photovoltaic cells to give the first photovoltaic cell module.
[0086] 4. The method of aspect 2 or 3, wherein during the allowing step the preassembled
laminate is inclined within plus-or-minus 30 degrees of vertical orientation such that the
10 opening in the second edge of the preassembled laminate is facing upward within plus-orminus
30 degrees of vertical orientation.
[0087] 5. The method of any one of aspects 1 to 4, wherein the liquid encapsulant flows in
the introducing and allowing steps under influence of gravity at ambient pressure.
Alternatively instead of, or additionally in addition to, gravity in the introducing step, the liquid
15 encapsulant may be introduced into the preassembled laminate under a pressure greater
than ambient pressure, e.g., pressure from 110 kPa to 200 kPa.
[0088] 6. The method of any one of aspects 1 to 3, wherein during the allowing step the
preassembled laminate is horizontally disposed with the superstrate or substrate facing
upward and within plus-or-minus 10 degrees of horizontal orientation and the liquid
20 encapsulant flows in the allowing step under influence of the weight of the superstrate or
substrate, respectively.
[0089] 7. The method of any one of aspects 1 to 6 further comprising after the allowing step
a step of sealing the opening in the second edge of the preassembled laminate to give a
second photovoltaic cell module sequentially comprising the superstrate, front portion of the
25 liquid encapsulant, interconnected photovoltaic cells, rear portion of the liquid encapsulant,
and substrate, and having a periphery entirely sealed against leakage of the liquid
encapsulant.
[0090] 8. The method of any one of the preceding aspects, the allowing step comprising
manipulating the first photovoltaic cell module to level the front portion of the liquid
30 encapsulant between the superstrate and photovoltaic cells and level the rear portion of the
liquid encapsulant between the photovoltaic cells and the substrate.
[0091] 9. The method of any one of the preceding aspects, wherein the liquid encapsulant is
curable, the method further comprising allowing the curable liquid encapsulant to cure to
give a third photovoltaic cell module sequentially comprising the superstrate, a front portion
DC11750NP1
24
of a cured encapsulant, the interconnected photovoltaic cells, a rear portion of the cured
encapsulant, and the substrate, and having the seal.
[0092] 10. The method of aspect 9 further comprising removing the seal from the third
photovoltaic cell module to give a fourth photovoltaic cell module sequentially comprising the
5 superstrate, front portion of the cured encapsulant, interconnected photovoltaic cells, rear
portion of the cured encapsulant, and substrate, and lacking the seal.
[0093] 11. The method of any one of the preceding aspects, wherein the photovoltaic cell
module further comprises a spacer/tie element disposed between and in operative contact
with the superstrate and the substrate.
10 [0094] 12. A photovoltaic cell module prepared according to the method of any one of
aspects 1 to 11.
[0095] 13. A kit comprising components and instructions for using same to manufacture a
photovoltaic cell module according to the method of any one of aspects 1-11.
DC11750NP1
25
What is claimed is:
1. A method of manufacturing a photovoltaic cell module from a preassembled laminate
comprising a superstrate, interconnected photovoltaic cells in need of encapsulation,
a substrate spaced apart from the superstrate so as to define a volumetric space
5 housing the photovoltaic cells and a front gap between the superstrate and the
photovoltaic cells and a rear gap between the photovoltaic cells and the substrate,
and a seal that operatively seals at least one first edge of the preassembled laminate
against leakage of a liquid encapsulant from the volumetric space and wherein the
preassembled laminate defines a second edge having an opening for allowing a
10 liquid encapsulant to flow from a source thereof that is exterior to the preassembled
laminate through the opening in the second edge and into the front and rear gaps of
the volumetric space, the method comprising:
introducing an effective amount of a liquid encapsulant through the opening
in the second edge of the preassembled laminate into the front and rear gaps of the
15 preassembled laminate and
allowing the introduced liquid encapsulant to fill the front gap between the
superstrate and photovoltaic cells and fill the rear gap between the photovoltaic cells
and the substrate so as to encapsulate the photovoltaic cells to give a first
photovoltaic cell module sequentially comprising the superstrate, a front portion of
20 the liquid encapsulant, interconnected photovoltaic cells, a rear portion of the liquid
encapsulant, and substrate, and also comprising the seal.
2. The method of claim 1, wherein during the introducing step the preassembled
laminate is inclined within plus-or-minus 30 degrees of vertical orientation such that
the opening in the second edge of the preassembled laminate is facing upward within
25 plus-or-minus 30 degrees of vertical orientation.
3. The method of claim 2, wherein the introducing step comprises pouring the liquid
encapsulant from a container through the opening in the second edge of the
preassembled laminate onto an upper portion of the photovoltaic cells and the
allowing step comprises allowing the introduced liquid encapsulant to coat the
30 photovoltaic cells and fill the front gap between the photovoltaic cells and the
superstrate and the rear gap between the photovoltaic cells and the substrate of the
preassembled laminate, thereby coating the photovoltaic cells to give the first
photovoltaic cell module.
DC11750NP1
26
4. The method of claim 2 or 3, wherein during the allowing step the preassembled
laminate is inclined within plus-or-minus 30 degrees of vertical orientation such that
the opening in the second edge of the preassembled laminate is facing upward within
plus-or-minus 30 degrees of vertical orientation.
5. The method of any 5 one of claims 1 to 4, wherein the liquid encapsulant flows in the
introducing and allowing steps under influence of gravity at ambient pressure.
6. The method of any one of claims 1 to 3, wherein during the allowing step the
preassembled laminate is horizontally disposed with the superstrate or substrate
facing upward and within plus-or-minus 10 degrees of horizontal orientation and the
10 liquid encapsulant flows in the allowing step under influence of the weight of the
superstrate or substrate, respectively.
7. The method of any one of claims 1 to 6 further comprising after the allowing step a
step of sealing the opening in the second edge of the preassembled laminate to give
a second photovoltaic cell module sequentially comprising the superstrate, front
15 portion of the liquid encapsulant, interconnected photovoltaic cells, rear portion of the
liquid encapsulant, and substrate, and having a periphery entirely sealed against
leakage of the liquid encapsulant.
8. The method of any one of the preceding claims, the allowing step comprising
manipulating the first photovoltaic cell module to level the front portion of the liquid
20 encapsulant between the superstrate and photovoltaic cells and level the rear portion
of the liquid encapsulant between the photovoltaic cells and the substrate.
9. The method of any one of the preceding claims, wherein the liquid encapsulant is
curable, the method further comprising allowing the curable liquid encapsulant to
cure to give a third photovoltaic cell module sequentially comprising the superstrate,
25 a front portion of a cured encapsulant, the interconnected photovoltaic cells, a rear
portion of the cured encapsulant, and the substrate, and having the seal.
10. The method of claim 9 further comprising removing the seal from the third
photovoltaic cell module to give a fourth photovoltaic cell module sequentially
comprising the superstrate, front portion of the cured encapsulant, interconnected
30 photovoltaic cells, rear portion of the cured encapsulant, and substrate, and lacking
the seal.
DC11750NP1
27
11. The method of any one of the preceding claims, wherein the photovoltaic cell module
further comprises a spacer/tie element disposed between and in operative contact
with the superstrate and the substrate.
12. A photovoltaic cell module prepared according to the method of any one of claims 1
5 to 11.
13. A kit comprising components and instructions for using same to manufacture a
photovoltaic cell module according to the method of any one of claims 1-11..