Adhesive bus bars in electrochromic windows
Embodiments described include adhesive bus bars for electrochromic or other optical state changing devices. The bus bars are configured to color match and/or provide minimal optical contrast with their surrounding environment in the optical device, provide better adhesion than ink based bus bars, as well as obviate the need to mitigate defects in underlaying layers.
1 . An electrochromic insulated glass unit comprising:
a first transparent substrate;
a second transparent substrate;
a spacer sandwiched between the first and second transparent substrates;
an electrochromic device coating disposed on the first transparent substrate, the electrochromic device coating comprising a first transparent conductive layer, a second transparent conductive layer and an electrochromic device stack disposed between the first and second transparent conductive layers, wherein the electrochromic device stack is disposed on the first transparent conductive layer, and wherein the second transparent conductive layer is disposed on the electrochromic device stack, and wherein the second transparent conductive layer is separated from the second transparent substrate by a space; and
a first adhesive bus bar on the first transparent conductive layer,
wherein the first adhesive bus bar comprises a first leg comprising (1) a first portion, between the first transparent substrate and the spacer, and (2) a second portion emanating from between the first transparent substrate and the spacer and extending to a secondary seal area.
2 . The electrochromic insulated glass unit of claim 1 , wherein the first adhesive bus bar comprises an electrically conductive adhesive and an electrically conductive backing.
3 . The electrochromic insulated glass unit of claim 2 , wherein the electrically conductive backing comprises at least one of a metal, a metallized plastic, a metallized woven fabric, a carbon fiber, an alloy, and a metallized carbon fiber.
4 . The electrochromic insulated glass unit of claim 2 , wherein the electrically conductive backing comprises a metal foil.
5 . The electrochromic insulated glass unit of claim 4 , wherein the metal foil comprises at least one of silver, aluminum, titanium, tin, zinc, gold, nickel, copper and alloys thereof.
6 . The electrochromic insulated glass unit of claim 5 , wherein the metal foil comprises a laminated metal.
7 . The electrochromic insulated glass unit of claim 6 , wherein the metal foil comprises tin-plated copper.
8 . The electrochromic insulated glass unit of claim 4 , where the metal foil comprises a doped metal.
9 . The electrochromic insulated glass unit of claim 8 , wherein the doped metal is silver doped with palladium.
10 . The electrochromic insulated glass unit of claim 1 , further comprising a second adhesive bus bar on the second transparent conductive layer.
11 . The electrochromic insulated glass unit of claim 10 , wherein the first and second adhesive bus bars have same composition.
12 . The electrochromic insulated glass unit of claim 6 , wherein the metal foil is between about 5 μm and about 100 μm thick.
13 . The electrochromic insulated glass unit of claim 4 , wherein the metal foil is between about 5 μm and about 50 μm thick.
14 . The electrochromic insulated glass unit of claim 4 , wherein the metal foil is between about 5 μm and about 40 μm thick.
15 . The electrochromic insulated glass unit of claim 4 , wherein the metal foil is between about 5 μm and about 20 μm thick.
16 . The electrochromic insulated glass unit of claim 2 , wherein the electrically conductive adhesive comprises an adhesive and a conductive filler.
17 . The electrochromic insulated glass unit of claim 16 , wherein the conductive filler is selected from the group consisting of silver, gold, nickel, copper, carbon black, carbon fiber, metalized carbon fiber, carbon nanotubes, fullerenes, graphite, metal-coated glass beads, metal-coated glass flakes, metal-coated glass fibers, and meta-coated nickel particles.
18 . The electrochromic insulated glass unit of claim 16 , wherein the conductive filler comprises metal-coated particles, wherein a metal coating on the metal-coated particles is selected from the group consisting of tin, silver, gold, copper and nickel.
19 . The electrochromic insulated glass unit of claim 16 , wherein the conductive filler comprises particles having shapes selected from the group consisting of spheres, rods, flakes, and irregular shapes.
20 . The electrochromic insulated glass unit of claim 19 , wherein the particles comprise a maximum dimension that does not exceed 25 μm or a minimum dimension that is not less than about 0.5 μm.
21 . The electrochromic insulated glass unit of claim 2 , wherein the first adhesive bus bar comprises same or similar color as the spacer and/or a primary sealant between the spacer and the first transparent substrate.
22 . The electrochromic insulated glass unit of claim 21 , wherein the electrically conductive backing comprises a color that approximates color of the spacer and/or the primary sealant.
23 . The electrochromic insulated glass unit of claim 21 , wherein the electrically conductive adhesive comprises a tinting agent so that the electrically conductive adhesive approximates color of the spacer and/or the primary sealant.
24 . The electrochromic insulated glass unit of claim 23 , wherein the tinting agent comprises at least one of carbon black, graphite, carbon nanotubes and fullerenes.
25 . The electrochromic insulated glass unit of claim 1 , wherein the first adhesive bus bar comprises:
a first leg between the first transparent substrate and the spacer, the first leg extending to a first vertex between the first transparent substrate and the spacer;
a second leg, extending from the first vertex, between the first transparent substrate and the spacer, extending along a second side of the spacer and to a second vertex between the first transparent substrate and the spacer; and
a third leg, extending from the second vertex, and including a first portion emanating from between the first transparent substrate and the spacer on the second side and outside an outer perimeter of the spacer, the first portion extending to an area proximate a corner of the first transparent substrate;
wherein the electrochromic insulated glass unit further comprises a second adhesive bus bar, the second adhesive bus bar comprising:
(a) a portion, between the first transparent substrate and the spacer, opposite a first side, and
(b) an other portion emanating from between the first transparent substrate and the spacer and terminating at the area.
26 . The electrochromic insulated glass unit of claim 25 , wherein the first transparent substrate and the spacer are rectangular.
27 . The electrochromic insulated glass unit of claim 25 , wherein the electrochromic device coating is a monolithic device whose perimeter edges lie between the spacer and the first transparent substrate.
28 . The electrochromic insulated glass unit of claim 27 , wherein the electrochromic device coating is all solid state and inorganic.
29 . The electrochromic insulated glass unit of claim 25 , wherein each adhesive bus bar of the first and second adhesive bus bars comprises an electrically conductive adhesive with a metal foil backing.
30 . The electrochromic insulated glass unit of claim 25 , wherein at least one of the first and second vertexes are fabricated by adhering two adhesive bus bar portion ends with or without pressure and/or heat.
31 . The electrochromic insulated glass unit of claim 30 , wherein the two adhesive bus bar portion ends are soldered together.
32 . The electrochromic insulated glass unit of claim 25 , wherein at least one of the first and second vertexes are fabricated by at least one of bending, folding, soldering, welding and brazing.
33 . The electrochromic insulated glass unit of claim 25 , wherein the area is between about 1 square inch and about 10 square inches.
34 . The electrochromic insulated glass unit of claim 25 , wherein the area is between about 2 square inches and about 5 square inches.
35 . The electrochromic insulated glass unit of claim 25 , wherein the area is between about 2 square inches and about 3 square inches.
36 . The electrochromic insulated glass unit of claim 1 , wherein the first adhesive bus bar comprises:
(1) a first leg between the first transparent substrate and the spacer, the first leg extending to a first vertex between the first transparent substrate and the spacer, and
(2) a second leg, extending from the first vertex, between the first transparent substrate and the spacer, and along a second side of the spacer, the second leg includes a portion emanating from between the first transparent substrate and the spacer on a third side of the spacer opposite a first side and extending to an area on and proximate a corner of the first transparent substrate outside an outer perimeter of the spacer;
wherein the electrochromic insulated glass unit further comprises a second adhesive bus bar, the second adhesive bus bar comprising:
(a) a first arm between the first transparent substrate and the spacer, the first arm extending to a first corner between the first transparent substrate and the spacer, and
(b) a second arm, extending from the first corner and includes a portion emanating from between the first transparent substrate and the spacer on the third side of the spacer and terminating at the area.
37 . The electrochromic insulated glass unit of claim 36 , wherein the first transparent substrate and the spacer are rectangular.
38 . The electrochromic insulated glass unit of claim 36 , wherein the electrochromic device coating is a monolithic device whose perimeter edges lie between the spacer and the first transparent substrate.
39 . The electrochromic insulated glass unit of claim 38 , wherein the electrochromic device coating is all solid state and inorganic.
40 . The electrochromic insulated glass unit of claim 36 , wherein each of the first and second adhesive bus bars comprises an electrically conductive adhesive with a metal foil backing.
41 . The electrochromic insulated glass unit of claim 36 , wherein each of the first vertex and the first corner are fabricated by adhering two adhesive bus bar portion ends with or without pressure and/or heat.
42 . The electrochromic insulated glass unit of claim 41 , wherein the two adhesive bus bar portion ends are soldered together.
43 . The electrochromic insulated glass unit of claim 36 , wherein the first vertex and the first corner are fabricated by at least one of bending, folding, soldering, welding and brazing.
44 . The electrochromic insulated glass unit of claim 36 , wherein the area is between about 1 square inch and about 10 square inches.
45 . The electrochromic insulated glass unit of claim 36 , wherein the area is between about 2 square inches and about 5 square inches.
46 . The electrochromic insulated glass unit of claim 36 , wherein the area is between about 2 square inches and about 3 square inches.