MANUFACTURING METHOD OF A REAR WINDOW FOR VEHICLES PROVIDED WITH A HEATER-INTEGRATED ANTENNA

Abstract

A manufacturing process of a rear window for vehicles including the following steps: provision of a glass plate with an external side suitable for being directed towards the exterior of the vehicle and an internal side suitable for being directed towards the interior of the vehicle; application of a heater on the internal side of the glass plate, the heater having two bus bars that are electrically connected to a positive pole and to a negative pole of a battery of the vehicle, respectively, and a plurality of horizontal heating lines that connect the bus bars; and application of antenna traces on the internal side of the glass plate, wherein the antenna traces have strips of transparent nanowires made of conductive material. The application of the antenna traces is made by spray-coating on the internal side of the glass plate.

Claims

1. Manufacturing process of a rear window for vehicles comprising the following steps: provision of a glass plate provided with an external side suitable for being directed towards the exterior of the vehicle and an internal side suitable for being directed towards the interior of the vehicle; application of a heater on the internal side of the glass plate, said heater comprising two bus bars that are electrically connected to a positive pole and to a negative pole of a battery of the vehicle, respectively, and a plurality of horizontal heating lines that connect the bus bars; and application of antenna traces on the internal side of the glass plate, wherein said antenna traces comprise strips of transparent nanowires made of conductive material, characterized in that said application of antenna traces is made by means of spray-coating on the internal side of the glass plate, said spray coating providing for the following steps: preparation of a printing ink with transparent nanowires; preparation of the internal side of the glass plate by means of cleaning and/or plasma activation; positioning and alignment of a printing mask on the internal side of the glass plate; spray coating of the printing ink; and thermal and/or optical post-treatment of the glass plate.

2. The method of claim 1, comprising the step of applying a transparent oxide layer by means of spray-coating on the internal side of said glass plate and of applying antenna traces comprising capacitive coupling traces by means of spray coating on said transparent oxide layer; wherein said transparent oxide layer is applied on a horizontal heating line and said capacitive coupling traces are disposed in proximal parallel position to said horizontal heating line whereon the transparent oxide layer (10) is applied.

3. The method of claim 2, wherein said capacitive coupling trace is overlapped to said horizontal heating line whereon the transparent oxide layer is applied, in such a way to define a vertical gap between said horizontal heating line and said capacitive coupling trace that is equal to the thickness of said transparent oxide layer, wherein said transparent oxide layer has a thickness less than 5 mm.

4. The method of claim 2, wherein said capacitive coupling trace is staggered with respect to said horizontal heating line whereon the transparent oxide layer is applied, in such a way to define a horizontal gap between an axis of said horizontal heating line and an axis of said capacitive coupling trace, wherein said horizontal gap is less than 5 mm and the thickness of said transparent oxide layer is less than 5 mm.

5. The method of claim 1, wherein said bus bars and said horizontal heating lines of the heater are obtained by means of spray-coating strips of transparent nanowires made of conductive material on the side of the glass plate.

6. The method of claim 1, wherein said nanowires comprise silver nanowires (AgNWs), copper nanowires (CuNWs), PEDOT: PSS or carbon nanotubes (CNT).

7. The method of claim 1, wherein said strips of transparent nanowires of the antenna traces have a thickness of 5-10 nm and are obtained by means of only one spray-coating layer.

8. The method of claim 5, wherein said strips of transparent nanowires of the bus bars of the heater have a thickness of 30-50 nm and are obtained by means of a plurality of spray-coating layers.

9. The method of claim 1, wherein said antenna traces comprise: intersecting traces that intersect the horizontal heating lines; and separate traces that do not intersect the heater.

10. The method of claim 1, wherein said antenna traces comprise direct coupling traces connected to a bus bar or to a horizontal heating line.

11. The method of claim 1, wherein said antenna traces comprise capacitive coupling traces in proximal parallel position to a horizontal heating line or to a bus bar and said rear window also comprises at least one planar adaptation structure connected to a capacitive coupling trace, said planar adaptation structure being obtained by means of spray-coating of strips of transparent strips made of conductive material on the internal side of the glass plate.

12. The method of claim 6, wherein said strips of transparent nanowires of the bus bars of the heater have a thickness of 30-50 nm and are obtained by means of a plurality of spray-coating layers.

13. The method of claim 7, wherein said strips of transparent nanowires of the bus bars of the heater have a thickness of 30-50 nm and are obtained by means of a plurality of spray-coating layers.

Description

[0074] Additional features of the invention will be clearer from the following detailed description, which refers to merely illustrative, not limiting embodiments, as shown in the appended figures, wherein:

[0075] FIG. 1 is a diagrammatic view of a nozzle for the deposition of nanowires;

[0076] FIG. 2 is an image of AgNW deposited in five layers on a substrate;

[0077] FIG. 3 illustrates the transmission of an AgNW film according to the number of layers;

[0078] FIG. 4(A) is a photograph of a synthesized solution of copper nanowires;

[0079] FIGS. 4(b) and 4(c) are SEM images of copper nanowires at low and high enlargement;

[0080] FIG. 4(d) is a conversion of binary images;

[0081] FIG. 4E illustrates the transmittance spectra for CuNW film by increasing wire density;

[0082] FIGS. 5 to 14 are nine diagrammatic views that illustrate nine possible embodiments of a rear window for vehicles according to the invention;

[0083] FIG. 5 is a cross-sectional view of a detail of FIG. 9;

[0084] FIG. 5 is a cross-sectional view of a detail of FIG. 10;

[0085] FIGS. 13A, 13B and 13C illustrate three different embodiments of planar adaptation structures.

[0086] With reference to FIGS. 5 to 14, the rear window of the invention is disclosed, which is generally indicated with reference numeral (1).

[0087] In the following description the terms “horizontal” and “vertical” refer to the arrangement of the lines in the Figures.

[0088] With reference to FIG. 5, the rear window (1) comprises a glass plate (2) with a substantially rectangular shape and suitable dimensions to cover a back part of the body of a vehicle.

[0089] For illustrative purposes, the glass plate (2) can be a tempered, multilayer or mono-layer glass with a thickness of approximately 5-8 mm.

[0090] The external side of the glass plate (2) is suitable for being directed towards the exterior of the vehicle and the internal side of the glass plate (2) is suitable for being directed towards the interior of the vehicle.

[0091] A heater (H) is applied on the internal side of the glass plate (2). The heater (H) comprises two bus bars (3) of conductive material that are disposed in vertical position near the lateral edges of the glass plate. The bus bars (3) are electrically connected respectively to a positive pole and to a negative pole of a battery of the vehicle, in such a way to define a potential difference between the two bus bars (3).

[0092] The bus bars (3) can be made in a traditional way, by means of screen-printing of a copper or silver conductive paste on the glass plate (2).

[0093] Advantageously, in order to obtain transparent bus bars, the bus bars (3) can be obtained by means of spray-coating of transparent nanowires on the glass plate (2), as illustrated above. For illustrative purpose, each bus bar (3) has a width of 6-30 mm, a length of 20-100 cm and a thickness of 30-50 nm obtained with the deposition of three layers of nanowires.

[0094] The bus bars (3) are connected by a plurality of horizontal heating lines (4). For instance, 16 horizontal heating lines can be provided in equally spaced parallel position.

[0095] The horizontal heating lines (4) can be made in a traditional way, by means of screen-printing of a copper or silver conductive paste on the glass plate (2).

[0096] Advantageously, in order to obtain transparent horizontal heating lines, the horizontal heating lines (4) can be obtained by means of spray-coating of transparent nanowires on the glass plate (2), as illustrated above. For illustrative purpose, each horizontal heating line (4) has a width of 1 mm, a length of 80 mm and a thickness of 10-20 nm obtained with the deposition of one layer of nanowires.

[0097] The application of a potential difference between the two bus bars (3) generates a circulation of current in the horizontal heating lines (4) that are heated, defogging the rear window (1).

[0098] The rear window (1) comprises antenna traces (A) (illustrated with a broken line in the figures) applied on the internal side of the glass plate (2). According to the invention, the antenna traces (A) are obtained by means of spray-coating of transparent nanowires on the glass plate (2), as illustrated above.

[0099] In FIG. 5, the antenna traces (A) comprise intersecting traces (5) and separate traces (6).

[0100] The intersecting traces (5) intersect the horizontal heating lines (4). The intersecting traces (5) are orthogonal to the horizontal heating lines (4) and intersect all the horizontal heating lines.

[0101] The separate traces (6) are disposed on the internal side of the glass plate (2) above the heater (H), forming a pattern, for example an “S”-shape (60) with vertical traces (61) that intersect the “S”-shape (60).

[0102] One end of the separate traces (6) is connected to a pad (7) applied on the side of the glass plate, usually the one that is not exposed to the external environment. The pad (7) can be made with transparent nanowires.

[0103] The pad (7) is electrically connected to an electronic component, such as an amplifier or impedance adapter that consists in a chip crimped or glued to the pad (7).

[0104] The intersecting traces (5) and the separate traces (6) are obtained by means of spray-coating of transparent nanowires. It must be considered that the intersecting traces (5) intersect the horizontal heating lines (4), but this is not a problem for the spray-coating of nanowires.

[0105] It must be considered that the intersecting traces (5) have a width of 1 mm, a thickness of 5-10 nm, and a length of 20-100 cm. Said intersecting traces (5) can be obtained by means of the nozzle (N) disclosed in FIG. 1.

[0106] The separate traces (6) can be easily obtained with the nozzle (N) of FIG. 1.

[0107] FIG. 6 illustrates an example wherein the antenna traces (A) comprise direct coupling traces (8), disposed in the plate (2) above the heater, in addition to the intersecting traces (5). A first direct coupling trace (8) is connected to a pad (7) and to a bus bar (3). A second direct coupling trace (8) is connected to a pad (7) and a horizontal heating line (4), such as the highest horizontal heating line.

[0108] The pads (7) are disposed in an upper region of the internal side of the plate and are suitable for being electrically connected to electronic components.

[0109] Also in such a case, the direct coupling traces (8) are obtained by means of spray-coating of transparent nanowires directly on the plate (2). The width and thickness of the direct coupling traces (8) are identical to the ones of the intersecting traces (5) and of the separate traces (6).

[0110] FIG. 7 illustrates an example of rear window wherein the antenna traces (A) comprise direct coupling intersecting traces (80) connected to pads (7) that are disposed on the plate (2) on the outside of the heater, intersecting one or more horizontal heating lines (4). Advantageously, the direct coupling intersecting traces (80) intersect the horizontal heating lines (4) with an angle other than 90°, for example an angle comprised between 60° and 80°.

[0111] The intersecting direct coupling traces (80) are realized with transparent nanowires technology, which permits to obtain a wide direct coupling band because the transparent nanowires have a controlled impedance value in order not to deviate the current flow that must only flow along the horizontal heating lines (4).

[0112] FIG. 8 illustrates an example wherein, in addition to the intersecting traces (5), the antenna traces (A) also comprise a capacitive coupling trace (9) disposed in the internal side of the plate (2) above the heater, in proximal parallel position to the highest horizontal heating line (4). The capacitive coupling trace (9) is connected to a pad (7) disposed in an upper region of the internal side of the plate and suitable for being electrically connected to electronic components, such as an amplifier or an impedance adapter.

[0113] Also in this case, the capacitive coupling trace (9) is obtained by spray-coating of transparent nanowires directly on the plate (2) and its wide and thickness are identical to the ones of the direct coupling traces (8, 80) of the intersecting traces (5) and of the separate traces (6).

[0114] It must be considered that, by using the spray-coating technology of transparent nanowires, the capacitive coupling trace (9) can be disposed in very proximal position to the horizontal heating line (4), for example at a distance lower than 8 mm, preferably lower than 5 mm, obtaining a better capacitive coupling than the prior art, wherein the capacitive coupling trace is at a distance higher than 8 mm from the horizontal heating line.

[0115] With reference to FIGS. 9 and 9A, the capacitive coupling trace (9) can be advantageously obtained by spray coating of transparent nanowires on a transparent oxide layer (10) (shown in grey in FIG. 9) deposited on the internal side of the glass plate (2).

[0116] The transparent oxide layer (10) is deposited on the horizontal heating line (4). As shown in FIG. 9A, a horizontal gap (d), in cross-section, lower than 8 mm, preferably lower than 5 mm, is provided between the capacitive coupling trace (9) and the horizontal heating line (4).

[0117] The capacitive coupling trace (9) is staggered relative to the horizontal heating line (4) whereon the transparent oxide layer (10) is applied, in such a way to define the horizontal gap (d) between an axis of the horizontal heating line (4) and an axis of the capacitive coupling trace (9). The horizontal gap (d) is lower than 5 mm and the transparent oxide layer (10) has a thickness lower than 5 mm.

[0118] The transparent oxide layer (10) avoids an ion migration between the capacitive coupling trace (9) and the horizontal heating line (4).

[0119] FIG. 9 illustrates a capacitive coupling trace (109) disposed on a transparent oxide layer (10) in proximal parallel position to a bus bar (3). In such a case, the transparent oxide layer (10) has an L-shape. The capacitive coupling trace (109) near the bus bar is connected to the capacitive coupling trace (9) that provides the coupling with the horizontal heating line (4).

[0120] FIGS. 10 and 10A illustrate an example wherein the capacitive coupling trace (9) is obtained by means of spray-coating on the transparent oxide layer (10) and is disposed in registered overlapped position relative to the horizontal heating line (4), i.e. with zero horizontal gap in cross-section. In view of the above, a vertical gap (s) is defined between the horizontal heating line (4) and the capacitive coupling line (9) that is equal to the thickness of the transparent oxide layer (10). Advantageously, the thickness of the transparent oxide layer (10) is lower than 5 mm.

[0121] Such a solution guarantees an efficacious capacitive coupling without any ion migration between the capacitive coupling trace (9) and the horizontal heating line (4).

[0122] FIG. 11 illustrates internal capacitive coupling traces (209) disposed inside the heater (H), as horizontal lines between two horizontal heating lines (4). The internal capacitive coupling traces (209) are connected to pads (7) disposed on the plate (2) on the outside of the heater by means of connecting traces (105) that cross the horizontal heating lines (4).

[0123] The rear window (1) also comprises capacitive internal traces (309) in vertical position which cross multiple horizontal heating lines and are coupled with the intersecting traces (5).

[0124] The rear window (1) also comprises: [0125] external stubs (400) disposed on the plate (2) on the outside of the heater and connected to a horizontal heating line (4); and [0126] internal stubs (401) disposed on the plate (2) on the inside of the heater, between two horizontal heating lines (4) and connected to a horizontal heating line (4).

[0127] FIG. 12 illustrates a rear window wherein the antenna traces (A) comprise oblique intersecting lines (50) that intersect multiple horizontal heating lines in oblique direction, for example with angles comprises between 30° and 50°.

[0128] Said oblique intersecting traces (50) are disposed according to two fan-like configurations (V1, V2) with origin (O) in a central section of the horizontal heating line (4) disposed at a higher height.

[0129] The oblique intersecting traces (50) are realized with high impedance nanowires in order not to deviate the current flows from the horizontal heating lines (4).

[0130] FIG. 13 illustrates an example of rear window, wherein the connection traces (105) are connected to a capacitive coupling trace (109) and to a planar adaptation structure (13) disposed on the plate (82) on the outside of the heater. The planar adaptation structure (13) is connected to a pad (7) disposed on the plate (2).

[0131] FIGS. 13A, 13B and 13C illustrate three examples of planar adaptation structures. The planar adaptation structures are transformers or stubs of concentrated inductance and capacity type.

[0132] The planar adaptation structures (13) are obtained by means of spray coating of transparent nanowires.

[0133] FIG. 14 illustrates an example of rear window wherein the horizontal heating lines (4) of the heater are obtained by means of spray coating with transparent nanowires and for this reason are shown with a broken line.

[0134] Although FIGS. 5 to 14 illustrate different examples of heater, with different types and layouts of the antenna traces (A), said types and layout of antenna traces can be combined one with another.