JP2000030847A - Electric heating window glass and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a joint good over a long period of time by arranging up and down bus bars between which a resistance heating wire is interposed, which supply power to the resistance heating wire, and joining the bus bars and the resistance heating wire with a conductive adhesive. SOLUTION: An upper bus bar 9 and a lower bus bar 8 made of the same material or different material of a thin copper tape or a plane braid copper wire, between which a resistance heating wire 6 is interposed, are arranged on an intermediate resin film 7. In order to facilitate the arrangement, the tape-like bus bar or a very thin copper tape is used. At least part of the lower bus bar 8 is buried in the intermediate resin film 7, the resistance heating wire 6 is stuck so as to cross to the lower bus bar 8 densely coated with an epoxy base thermosetting type conductive adhesive 10, and the upper bus bar 9 is placed on the resistance heating wire 6 so as to cross, and they are heat-bonded. Spaces between the resistance heating wire 6 and the upper and lower bus bars 9, 8 are filled with the conductive adhesive 10, adhesion between the resistance heating wire 6 and the upper and lower bus bars 9, 8 is enhanced, and good electric conduction is kept for a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrically heated window glass and a method for manufacturing the same, and more particularly, to an electrically heated window glass for a vehicle which exhibits uniform and quick snow melting, ice melting, frosting and anti-fog effects, and a method for manufacturing the same. .

[0002]

2. Description of the Related Art In a severe winter or a cold region, snow, icing, frosting or clouding occurs on windshields, rear glasses, etc. of trains, trains, trucks, passenger cars, etc., but it is difficult to quickly remove them. It is. As a method for solving these problems, it has been proposed to use an electrically heated window glass as a window glass.

For example, bus bars (electrodes) are arranged substantially in parallel on the upper side and the lower side of glass, respectively, and several hundred resistance heating wires are provided so as to pass between the upper side bus bar and the lower side bus bar. Electric window glasses for windshields of passenger cars have been proposed.

[0004] The electrically heated window glass is generally composed of two glass sheets, an intermediate film sandwiched between the two glass sheets, a pair of bus bars provided between the two glass sheets and provided in a peripheral portion thereof, and It is composed of a number of resistance heating wires provided between a pair of bus bars.

As the resistance heating wire, an ultrafine tungsten wire or a molybdenum wire which is hardly visible to the naked eye is used so as not to hinder the transparency of the window glass. Power is supplied to these resistance heating wires from a battery or the like via a bus bar to cause the window glass to generate heat, and this heat causes snow melting, ice melting, frost melting, and the like.

Conventionally, a bus bar is composed of an upper tape-shaped bus bar and a lower tape-shaped bus bar so as to sandwich the resistance heating wire, and the resistance heating wire is connected to the upper tape-shaped bus bar and the lower tape-shaped bus bar. In the case of bonding and fixing to a bus bar, it has been performed only with solder. However, in the vicinity of the resistance heating wire sandwiched between the upper and lower tape-shaped bus bars, the solder does not stay and a gap is generated.

Therefore, the upper and lower tape-shaped bus bars and the resistance heating wire cannot be in close contact with each other, and the resistance heating wire may move during use. As a result, there is a problem that a contact resistance is provided between the bus bar and the resistance heating wire, heat is generated between the bus bar and the resistance heating wire, and power cannot be supplied to the resistance heating wire.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electric heating windowpane in which the connection between the bus bar and the resistance heating wire in the electric heating windowpane can be maintained well over a long period of time, and a method of manufacturing the same. I do.

[0009]

According to the present invention, there is provided an electric heating window glass in which two sheets of glass are joined via an intermediate resin film and a resistance heating wire is provided between the two sheets of glass. The busbar to supply power consists of an upper busbar and a lower busbar so as to sandwich the resistance heating wire,
Provided is an electrically heated window glass characterized in that a conductive adhesive is provided together with a solder layer at a joint between a bus bar and a resistance heating wire.

According to the present invention, there is further provided a method for manufacturing an electrically heated window glass comprising two sheet glasses joined together with an intermediate resin film therebetween and a resistance heating wire provided between the two sheet glasses. The bus bar consists of an upper bus bar and a lower bus bar so as to sandwich the resistance heating wire,
A preliminary solder layer is provided on the surface of the upper bus bar and the lower bus bar on the resistance heating wire side, and a conductive adhesive is applied to at least a part of the surface and / or a surface to be joined to the resistance heating wire bus bar. And a method of manufacturing an electrically heated window glass characterized by joining a resistance heating wire to a bus bar.

The adhesion between the resistance heating wire and the bus bar is improved by applying the conductive adhesive. The preliminary solder layer has a melting point of 8
It is solder of 0 to 300 ° C. and has a thickness of 1 to 100 μm.
m is preferable.

The conductive adhesive is not particularly limited as long as it improves solder wettability. For example, any of a thermosetting type, a room temperature setting type, and an ultraviolet ray setting type conductive adhesive can be used. In addition, urethane-based, epoxy-based, silicone-based, or acrylic-based conductive adhesives can be used, but good results can be obtained. It is preferable to use a curable conductive adhesive. The conductive adhesive preferably contains at least one selected from the group consisting of silver, nickel and carbon. In particular, it is preferable that silver is contained. The specific resistance of the conductive adhesive is 1Ω
M is preferably equal to or less than m.

[0013]

FIG. 1 is a plan view of an example of an electrically heated window glass according to the present invention (the upper glass sheet, which is one of the glass sheets, is omitted in the drawing). One of the glass sheets 1 constituting the laminated glass is a trapezoid whose lower side is longer than the upper side (for example, 104 cm on the upper side, 148 cm on the lower side, and 83 cm in height).

The electric heating window glass A is provided with bus bars 2a, 2b on the left and right sides of the upper side, and the bus bars 3a,
3b are provided, and lead wires 4a, 4
b, 5a and 5b are provided so that power is supplied from a battery (not shown). The width of each busbar is about 3-1
0 mm. In FIG. 1, 2a and 3a correspond to 2b
And 3b form a pair.

Between the upper bus bars 2a and 2b and the lower bus bars 3a and 3b, resistance heating wires 6 having a wire diameter of 10 to 35 μm are arranged in parallel at an interval of 1.5 to 4.0 mm in a substantially rectangular portion. Has been established. The resistance heating wire 6 is preferably arranged in a sine wave shape having an amplitude of 0.2 to 1.5 mm and a wavelength of 2 to 8 mm in parallel. With such a shape, the temperature distribution when the electric heating window glass A generates heat becomes more uniform. In addition, it is not optical and is optically preferable.

The resistance heating wire 6 is preferably a tungsten wire or a molybdenum wire, and preferably has a diameter in the range of 10 to 35 μm.

FIG. 2B is a sectional view taken along the line XX of FIG. 1 (a sectional view at a position where the bus bar exists). FIG. 2B shows FIG.
In the figure, a plate glass 1 'on the upper surface which is omitted is also shown. As shown in FIG. 2B, the electric window glass of the present invention has an intermediate resin film 7 provided on the surface of the glass sheet glass 1 and a lower bus bar (hereinafter, referred to as a lower bus bar) 8 constituting a lower portion of the bus bar thereon. , A resistance heating wire 6, an upper bus bar (hereinafter, referred to as an upper bus bar) 9 constituting an upper portion of the bus bar, and an upper plate glass 1 'are laminated in this order. The space between the lower bus bar 8 and the upper bus bar 9 is filled with a conductive adhesive 10.

The lower bus bar 8 and the upper bus bar 9 may be made of the same material or different materials. Examples of the material forming the bus bar include a thin copper tape and a flat braided copper wire. It is preferable to use a tape-shaped bus bar, particularly a thin copper tape, because it is easy to provide the bus bar on the intermediate resin film 7. The spare solder layer
For example, a thin copper tape coated on both sides with a thickness of 15 μm and having a melting point of 95 to 130 ° C. is used.

The total thickness of the lower bus bar 8, the conductive adhesive 10 and the upper bus bar 9 is preferably as thin as possible.
The thickness is preferably about 0.4 mm. It is preferable that at least a part of the lower bus bar 8 is embedded in the intermediate resin film 7.

An example of a method of joining the bus bar and the resistance heating wire 6 will be described. After attaching the lower bus bar 8 to the intermediate resin film 7, the resistance heating wire 6 is attached thereon. A conductive adhesive (for example, an epoxy-based heat-curable conductive adhesive) is applied on the lower bus bar 8 where the resistance heating wire 6 intersects with a brush or brush so as not to leave any residue. Further, the upper bus bar 9 is thermocompressed and adhered thereon.

FIG. 2A is a schematic cross-sectional view showing a case where a conventional conductive adhesive is not applied. When the bus bar and the resistance heating wire 6 are joined only by the solder on the bus bar surface, the resistance heating wire 6
, A gap is formed in the vicinity, and the bus bar and the resistance heating wire 6 cannot be in close contact. For this reason, a contact resistance is generated between the bus bar and the resistance heating wire 6, which causes a problem that heat is generated between the bus bar and the resistance heating wire 6 and that the resistance heating wire 6 cannot be heated during use.

On the other hand, when the conductive adhesive layer 10 is applied (FIG. 2B), the conductive adhesive fills the space between the bus bar and the resistance heating wire 6, so that the bus bar and the resistance heating wire 6 adhere to each other. Is improved, and good conduction is maintained for a long period of time.

When the conductive adhesive is not applied as shown in FIG. 2A, the bonding strength by the peel test is 100 gf / 25c.
m. On the other hand, when a conductive adhesive is applied as shown in FIG. 2B (in this example, a tungsten wire was used as a resistance heating wire, a thin copper tape was used as a bus bar, and an acrylic curable conductive adhesive was used as a conductive adhesive. ) Is 2kgf
/ 25 cm. Also, as a result of a 60-cycle (30-day) cooling / heating cycle test, when there was no conductive adhesive, there was a + 23% change in the resistance value before the test. , + 1.5%.

[0024]

According to the present invention, the gap between the upper and lower tape-shaped electrodes is filled with a solder layer, and the resistance heating wire is closely attached to and fixed to the bus bar. Is maintained well over a long period of time, and good conduction is maintained over a long period of time.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a plane of an example of an electrically heated window glass according to the present invention.

FIG. 2A is a sectional view taken along the line XX of FIG. 1; (B) A schematic cross-sectional view of a conventional electric heating window glass.

[Explanation of symbols]

 A: Electric heating window glass 1: Plate glass 2, 3: Bus bar 4, 5: Lead wire 6: Resistance heating wire 7: Intermediate resin film 8: Lower bus bar 9: Upper bus bar 10: Conductive adhesive

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference)

Claims (5)

[Claims] 1. An electric heating window glass in which two sheets of glass are joined via an intermediate resin film and a resistance heating wire is provided between the two sheets of glass, wherein a bus bar for supplying power to the resistance heating wire comprises a resistance heating wire. An electrically heated window glass comprising an upper bus bar and a lower bus bar so as to sandwich the same, and a conductive adhesive is provided together with a solder layer at a joint between the bus bar and the resistance heating wire. 2. The electrothermal window glass according to claim 1, wherein the conductive adhesive is a urethane-based, epoxy-based, silicone-based, or acrylic-based conductive adhesive. 3. A method of manufacturing an electrically heated window glass in which two glass sheets are joined via an intermediate resin film and a resistance heating wire is provided between the two glass sheets, wherein a bus bar for supplying power to the resistance heating wire includes: Consisting of an upper bus bar and a lower bus bar so as to sandwich the resistance heating wire, a preliminary solder layer is provided on the surface of the upper bus bar and the lower bus bar on the resistance heating wire side, and at least a part of the surface and And / or applying a conductive adhesive to the surface of the resistance heating wire to be joined to the bus bar, and joining the resistance heating wire to the bus bar. 4. The preliminary solder layer is a solder having a melting point of 80 to 300 ° C. and a thickness of 1 to 100 μm.
The method for producing the electrically heated window glass according to the above. 5. The method according to claim 3, wherein the conductive adhesive is a urethane-based, epoxy-based, silicon-based or acrylic-based conductive adhesive. .