SWITCHABLE LAMINATED GLAZING WITH IMPROVED BUS BAR

Abstract

A switchable laminated glazing with improved bus bar that solves the problem of inhomogeneities and reduce the cost of its fabrication by providing a laminated glazing that comprise a switchable layer (14) that has an active material sandwiched between two conductive coated plastic layers (8), at least two bus bars (20) in electrical contact with the respective conductive coated plastic layer (8), and at least two pliable conductive media (12), each of them between the respective coated plastic layer (8) and bus bar (20). The area covered by pliable conductive medias (12) is substantially less than the area covered by bus bars (20). The invention provides an improved lower cost bus bar by sparing use of a pliable conductive media and by using a pliable conductive media in different kind of configurations.

Claims

1. A switchable laminated glazing comprising: at least one switchable layer; at least two bus bars; at least two pliable conductive media; wherein the at least one switchable layer has an active material sandwiched between two conductive coated plastic layers, being the coated surfaces in contact with the active material; wherein each of the at least two bus bars is in electrical contact with a coated surface of the respective conductive coated plastic layer; wherein each of the at least two pliable conductive media is located between the coated surface of the respective conductive coated plastic layer and its corresponding bus bar; wherein the area covered by each of the at least two pliable conductive media is substantially less than the area covered by its corresponding bus bar.

2. The switchable laminated glazing of claim 1, wherein the pliable conductive media is comprised of metallic particles suspended in a liquid.

3. The switchable laminated glazing of claim 1, wherein the pliable conductive media forms a discontinuous trace.

4. The switchable laminated glazing of claim 1, wherein the pliable conductive media forms a continuous trace.

5. The switchable laminated glazing of claim 1, wherein the bus bar has a configuration selected from the group of straight line, L-shaped and U-shaped.

6. The switchable laminated glazing of claim 1, wherein a conductive adhesive is used to bond the bus bar to the pliable conductive media.

7. The switchable laminated glazing of claim 6, wherein the conductive adhesive partially overlaps the pliable conductive media.

8. The switchable laminated glazing of claim 1, wherein a tape over the bus bar is used to secure the bus bar to the film.

9. The switchable laminated glazing of claim 1, where in a flexible printed circuit (FPC) is located between the pliable conductive media and the bus bar, and is in contact with the pliable conductive media through conductive adhesive means.

10. The switchable laminated glazing of claim 1, wherein a sealing material covers the edges of the at least one switchable layer.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0037]

TABLE-US-00001 1 Cross Section 2 Exploded Cross Section: full conductive adhesive. 3 Panoramic Roof: Exploded View 4 Film: Exploded View 5 Film: Exploded View 6 Exploded Cross Section: partial conductive adhesive.

REFERENCE NUMERALS OF DRAWINGS

[0038]

TABLE-US-00002  2 Glass  4 Bonding/Adhesive Layer (interlayer)  6 Obscuration/Black Frit  8 Plastic (PET) 10 TCO Coating 12 Pliable Conductive Media (Silver Paste) 14 Active Material Layer (Emulsion) 20 Bus Bar 22 Conductive Adhesive 28 Switchable Film

Detailed Description of the Invention

[0039] Embodiment 1: A laminated switchable panoramic roof (FIG. 3) is comprised of two 2.4 mm layers of solar green soda-lime glass 2. Two sheets of gray bonding interlayer 4 are used to bond a single sheet of switchable film (SPD film) 28 to the glass layers 2. The total visible light transmission of the laminate in the on state is 5%, in the off state, 27%. Along each long edge, one edge of each TCO coated layer 10 is cut back 12 mm along the entire length. The cut backs are made on opposite surfaces and sides. The cut back exposes the active material layer. The active material is scraped off with a plastic scraper. The surface is then cleaned using a solvent such as alcohol, hexane, heptane, among others. As shown in FIG. 4, a continuous 3 mm wide line is then printed directly onto the TCO surface 10, 6 mm inboard from the edge using a pliable conductive material (silver via paste) 12. The pliable conductive material (silver via paste) 12 is dried using a hot air blower or any other suitable means such as IR lamps, UV lamps or laser. A 6 mm wide strip of 2 oz. copper Bus bar 20 with a backing of 50 μm conductive adhesive 22 is then adhered to the exposed TCO 10 and pliable conductive material (silver via paste) 12, centering it with the cut back.

[0040] Embodiment 2: This embodiment is the same as embodiment 1 with the exception of the silver via print. 3 mm diameter circles are printed every 25 mm along the edge (such as the ones shown in FIG. 5).

[0041] Embodiment 3: This embodiment is the same as embodiment 1 with the exception of the silver via print. A 1.5 mm continuous line of silver via paste 12 is printed along the length of the cut back and centered with the cut back.

[0042] Embodiment 4: This embodiment is the same as embodiments 1 to 3 but without the conductive adhesive. The copper bus bar is placed directly in contact with the pliable conductive media (silver via print) and the TCO coating, such the cooper bus bar shown in FIG. 5.

[0043] Embodiment 5: This embodiment is the same as embodiments 1 to 3 but with the conductive adhesive 22 applied along the length of the copper bus bar 20 in two 2 mm wide separate strips on either side of the 3 mm pliable conductive media 12 such that the conductive adhesive 22 only partially overlaps the pliable conductive media 12. The copper bus bar 20 is placed in contact with the pliable conductive media (silver via print) 12, such the cooper bus bar shown in FIG. 6.

[0044] Embodiment 6: A laminated switchable panoramic roof (FIG. 3) is comprised of two 2.4 mm layers of solar green soda-lime glass 2. Two sheets of gray interlayer 4 are used to bond a single sheet of switchable layer (SPD film) 28 to the glass layers 2. The total visible light transmission of the laminate in the on state is 5%, in the off state, 27%. Along each long edge, one edge of each TCO coated layer 10 is cut back in a range of 5 mm-15 mm along the entire length. The cut backs are made on opposite surfaces and sides. The cut back exposes the active material layer. The active material is scraped off with a plastic scraper. The surface is then cleaned using a solvent such as alcohol, hexane, heptane, among others. As shown in FIG. 4, a continuous 3 mm wide line is then printed directly onto the TCO surface 10, 6 mm inboard from the edge using a pliable conductive media (silver via paste) 12. The pliable conductive media (silver via paste) 12 is dried using a hot air blower or any other suitable means such as IR lamps, UV lamps or laser. A 6 mm wide strip of 2 oz. copper Bus bar 20 with a backing of 50 μm conductive adhesive 22 is then adhered to the exposed TCO 10 and conductive media (silver via paste) 12, centering it with the cut back.