JPS6255244A - Forming electrode of transparent conductive thin film - Google Patents

Abstract

PURPOSE:To make a transparent conductive thin film not to be affected by heat treatment by forming the transparent conductive thin film after finishing silver paste baking. CONSTITUTION:As an electrode, silver paste 2 containing glass frit is screen printed on the electrode forming section at the end of a glass plate 1. The glass plate 1 baked with the silver paste 2 is then placed in a sputtering vacuum chamber to form an ITO film as a transparent conductive thin film over which a silicon dioxide film 4 as an insulation protection film is formed. Then the ITO film 3 and the silicon dioxide film 4 both formed on the silver paste 2 are removed by polishing to expose the silver paste 2 on which a lead 5 is attached and finally the electrode forming section is sealed with sealing polymer 6.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for forming electrodes on a transparent conductive thin film, and more specifically, for forming electrode terminals on a transparent conductive thin film formed on a transparent substrate such as glass. Regarding how to.

[Conventional technology]

In recent years, IT technology has been used to equip car windows and mirrors with heater functions and electromagnetic shielding functions for anti-fog purposes.
Formation of a transparent conductive thin film such as an O film has been considered, and 1031 people have also made several proposals regarding this matter (for example, Toku IJI 1973-1357. 7
No. 6, Miki Sho 6o-t5s.

No. 9, Utility Application No. 59-84013, etc.).

By the way, in order for the transparent conductive thin film to exhibit a heater function, it is necessary to supply a voltage to the transparent conductive thin film. For this reason, electrode terminals are usually formed at the ends of the transparent conductive m film on the transparent substrate, and lead wires are connected to the electrodes.

To explain this in more detail, forming electrodes on a transparent conductive thin film has generally been carried out through a process as shown in FIG.

That is, as shown in FIG. 3+81, a transparent conductive thin film 3 such as an ITO film is first deposited to a predetermined thickness on a well-washed and dried glass plate 1 as a transparent substrate by a vacuum film forming method such as a sputtering method. to form. Next, the transparent conductive thin film 3 was removed from the vacuum chamber, and as shown in FIG.
dry. Thereafter, the insulating image m film 4 is formed again by the vacuum film forming method in the vacuum chamber. As a result, the state shown in FIG. 3 (C1) is obtained. Next, as shown in FIG. An electrode material is applied and at the same time lead wires 5 are connected to this silver paste 2. Then, heat treatment is performed to obtain the state shown in FIG. 3+81.

Finally, as shown in FIG. 3 1fl, the electrode forming portion is covered with a sealing resin 6.

[Problem that the invention seeks to solve]

By the way, in the above-mentioned conventional electrode forming method, after forming the transparent conductive thin film, it is necessary to perform masking, so the transparent conductive thin film is removed from the through-hole tank and exposed to the atmosphere. Therefore, the surface of the transparent conductive thin film may be oxidized or contaminated, and the adhesion between the transparent conductive thin film and the insulating protective film may be insufficient.

Furthermore, since heat treatment is performed after applying the silver paste, the characteristics of the transparent conductive thin film may be deteriorated depending on the type of the transparent conductive thin film.

Therefore, there has been a need for an electrode forming method that ensures adhesion between the transparent conductive thin film and the insulating protective film and does not deteriorate the transparent conductive thin film.

[Means for solving problems]

The above problem is solved by the method for forming an electrode of a transparent conductive thin film of the present invention, which will be described below.

That is, the present invention provides a method for forming an electrode terminal on a transparent conductive 14:M film on a transparent substrate on which a transparent conductive thin film and an insulating protective film are formed, the method comprising: After baking a paste containing a conductive substance, a transparent conductive thin film and an insulating protective film are formed in this order on a transparent substrate containing this paste using a vacuum film forming method, and then a transparent conductive thin film and an insulating protective film are formed on the paste. After removing the paste, a ladle lead wire is connected 17 by soldering or the like onto this paste, and finally the electrode forming part is covered with a sealing resin. -・-1111 First Invention The present invention also provides a method for forming an electrode terminal on a transparent conductive thin film on a transparent substrate on which a transparent conductive thin film and an insulation II film are formed. , After baking a paste containing a conductive substance on the electrode forming portion of the transparent substrate, a transparent conductive thin film and an insulating image tIs are formed in this order on the transparent substrate containing this paste by a vacuum film forming method, and then the paste is applied. Transparent conductive thin film and insulating image on the top! The method is characterized by applying an ultrasonic soldering iron to the membrane, performing ultrasonic soldering using a conductive substance to connect the lead wires, and finally covering the electrode forming part with a sealing resin.

-1----Second Invention The present invention provides an automobile windshield glass, a back cover (
It can be applied to forming transparent conductive thin films on window glass such as rear window glass and side window glass, door mirrors, etc.

In the present invention, transparent resins such as polyacrylonitrile and polycarbonate, glass, etc. can be used as the transparent substrate.

The electrode forming portion is a portion of the transparent substrate that forms electrodes, which are terminals for supplying power to the transparent conductive thin film. Therefore,
It is provided at least two places on the transparent substrate, generally at the ends of the surface of the transparent substrate.

As a transparent conductive thin film, indium oxide (InlO
x), tin (
Indium oxide using Sn) or fluorine (F)
ITO solution, indium oxide-fluorine solid solution, tin dioxide (S n Ox ), which contains fluorine (F), phosphorus (P), or antimony (S n Ox ) as a dopant.
A tin dioxide-fluorine solid solution, a tin dioxide-phosphorus solid solution, a tin dioxide-antimony solid solution using b) can be used, and furthermore, gold (Au), silver (Ag), copper (C11), chromium (Cr), Palladium (Pd), Rhodium (Rh)
) or a metal (alloy) thin film made of an alloy thereof.

This transparent conductive thin film is produced on a transparent substrate using vacuum deposition methods such as vacuum evaporation, sputtering, and ion blasting.
: is formed.

The electrode functions as a terminal for supplying current to the transparent conductive F# film. As the electrode, aluminum (A
l), nickel (Ni), silver (Ag), chromium (Cr)
Low resistance materials such as can be used. This electrode is formed by baking a conductive paste or the like. The film thickness of this electrode may vary by about 2008 to 300. Note that a lead wire is added to this electrode by soldering, brazing, etc., and this lead wire is connected to an on-vehicle battery power source or the like via a switch.

Furthermore, an insulating protective film such as a silicon dioxide film is formed on the transparent substrate to insulate and protect the transparent conductive thin film. This insulation! is formed by a vacuum film forming method similarly to the transparent conductive thin film.

In the electrode forming method of the present invention, a conductive paste is first printed or applied on the electrode forming portion of a transparent substrate, and then baked. Next, it is placed in a vacuum chamber for vacuum film formation,
A transparent conductive thin film and an insulating film are continuously formed using an appropriate vacuum film forming method such as a vacuum evaporation method, a sputtering method, an ion blating method, etc. without taking the film out of the vacuum chamber.

Thereafter, in the first invention, the conductive pasted transparent conductive thin film and the insulating protective film are coated with aluminum fine powder or -1000
After removing the above by polishing with sandpaper, etc., connect the lead wires on top of the conductive paste using room temperature dry conductive paste or solder, and then cover the electrode forming part with sealing resin to ensure complete insulation and sealing. shall be taken as a thing.

Further, in the second invention, unlike the first invention, the transparent conductive thin film of the conductive paste and the insulating protective film are not removed (the wire is connected with an ultrasonic soldering iron using a conductive material). At this time, the transparent conductive thin film and insulating protective film of the conductive paste are automatically removed by the ultrasonic waves applied during soldering, the conductive paste and conductive material are connected, and the lead wires are connected. Then, by covering the electrode forming part with a sealing resin,
Insulate and seal.

[Effect]

According to the method for forming electrodes of a transparent conductive thin film of the present invention, a conductive paste is first formed on a transparent substrate without using a masking material as in the conventional method, so that a transparent conductive thin film and an insulation layer can be formed. The film can be formed continuously without taking it out of the vacuum chamber. Therefore, oxidation and contamination of the transparent conductive thin film due to exposure to the atmosphere can be prevented, and good adhesion between the transparent conductive thin film and the insulating protective film can be maintained.

Also, baking (heat treatment) is performed after applying or printing the conductive paste, but in the case of the present invention, unlike the conventional method, a transparent conductive thin film is formed after baking the conductive paste. Deterioration of the transparent conductive thin film due to heat treatment is prevented.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

(First Example) As a first example, the first invention will be described with reference to FIG.

Here, FIG. F is a process diagram showing a method for forming a transparent conductive ms electrode according to a first embodiment of the present invention.

First, a glass plate l used for automobile window glass is prepared as a transparent substrate, and after thoroughly cleaning it with an organic solvent and pure water, a silver paste 2 containing a glass frit is applied as an electrode to the glass plate shown in FIG. As shown, the electrode formation area at the end of the glass plate 1 is screen printed, dried at 150°C for 20 minutes, and then baked at 450°C for 30 minutes.At this time, in order to eliminate the level difference (usually about 50 μm) with the electrode surface. Then, polishing is performed using an abrasive containing fine alumina powder to eliminate the steps and create a gently sloped surface.

Subsequently, the glass plate 1 on which the silver paste 2 had been baked was placed in a sputtering tank, and an ITO film 3 was formed as a transparent conductive thin film by sputtering. That is, a glass plate 1 is placed on the anode side in a sputtering vacuum chamber, and indium oxide (Ink('),
) An ITO sintering target containing 10% by weight of tin dioxide (SnO, ) was installed. Then, inside the vacuum chamber, 2X10-
After evacuation to about 'Torr, argon gas is introduced to about 2XIO-Torr. In this state, an IKW sputtering voltage is applied to form an IT (transparent conductive) film.
) A film 3 having a thickness of about 1 μm was formed. The situation at this time is shown in Figure F+
Shown in b).

Next, without taking the glass plate 1 out of the vacuum chamber, the evaporation source on the cathode side was changed to silicon dioxide, and the process was carried out in substantially the same manner as in the case of the transparent conductive thin film. A silicon dioxide 114 as an insulating protective film was formed on the substrate 3 to a thickness of about 1000 nm.

As a result, the state shown in FIG. 1 1dl was obtained.

Next, the ITO film 3 and silicon dioxide film 4 formed on the silver paste 2 were removed by polishing using an abrasive containing fine alumina powder, resulting in the state shown in FIG. 1dl.

Thereafter, a lead wire 5 was attached to the exposed silver paste 2 using a silver paste dried at room temperature, and finally the electrode forming part was sealed with a sealing resin 6.

As a result, a conductive transparent member shown in FIG. 1 (el) was obtained.

The conductive transparent member obtained as above was successively coated with an ITO film (transparent conductive material M) and a silicon dioxide film (
Since a transparent conductive thin film (insulating protective film) is formed, the transparent conductive thin film is not exposed to the atmosphere after formation as in the conventional case, and deterioration of the surface of the transparent conductive thin film due to exposure to the atmosphere is prevented by +1.

Therefore, the adhesion between the transparent conductive thin film and the insulating protective film is improved.

However, since the transparent conductive thin film is formed after baking (heat treatment) the silver paste, the transparent conductive thin film is not affected by the heat treatment, and deterioration of characteristics due to heat treatment is prevented.

(Second Embodiment) As a second practical example, a second invention will be described with reference to FIG.

Here, FIG. 2 is a process diagram showing a method for forming an electrode of a transparent conductive thin film according to a second embodiment of the present invention.

In the second embodiment, the steps shown in ζ and FIG. 2+al to FIG. 2tc+ are the same as in the first embodiment, and therefore their explanations will be omitted.

After forming a silver paste 2, an ITO film 3 and a silicon dioxide film 4 on a glass plate 1, as shown in FIG. A lead wire 5 is connected to the film 3 and the silicon dioxide film 4 using an ultrasonic soldering iron.As a result, the lead wire 5 is connected to the silver alloy 7, and the ITO on the silver paste 2 is soldered by ultrasonic waves. Film 3 and silicon dioxide film 4 are destroyed and removed, and silver paste 2 and silver alloy 7 are connected.

Thereafter, as shown in FIG. 2+8), the periphery of the electrode forming portion was covered with a sealing resin 6, thereby obtaining the conductive transparent member shown in FIG. 2+8).

The conductive transparent member obtained as a result not only has the same effect as the first example, but also has the ability to
Since it is not necessary to remove the O film and the silicon dioxide film by polishing, an excellent effect is achieved in that one electrode forming step can be omitted.

Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, but includes various embodiments within the scope of the claims.

For example, in the first embodiment, room temperature drying silver paste was used to attach the 1j lead wire, but the lead wire may be attached using solder.

In addition, in Examples, a transparent conductive thin film and an insulating image il! Although a sputtering method was used as a method for forming the film, other vacuum evaporation methods or ion blating methods may be used.

〔Effect of the invention〕

As described above, the transparent conductive thin film electrode forming method of the present invention provides the following effects.

(a) The adhesion between the transparent conductive thin film and the insulating protective film is significantly improved.

(n) Prevents deterioration of the j3 bright conductive thin film and improves quality
++ can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a process diagram showing a method for forming electrodes of a transparent conductive thin film according to the first embodiment of the present invention, and Fig. 2 shows a method of forming electrodes of a transparent conductive thin film according to the second embodiment of the present invention. Process Diagram FIG. 3 is a process diagram showing a conventional method for forming electrodes of a transparent conductive thin film. 1---Glass plate (transparent substrate) 2-11--Silver paste (electrode) 3------ ITO film (transparent IJ lrfI
Film) 4.--Silicon dioxide film (insulating protective film) 5.
・-----・-Lead wire 6------Sealing resin 7--Silver alloy (conductive material) Applicant: Toyota Motor Corporation Figure 2 +a1 mkaku■] Seal = 2? -17 (d) 5 〆(b) \\ゝ 1 \\\\\, \, death] 1 . (eJ +a) (d)

Claims (2)

[Claims] (1) A method of forming electrode terminals on a transparent conductive thin film on a transparent substrate on which a transparent conductive thin film and an insulating protective film are formed, the method comprising: a paste containing a conductive substance in the electrode forming portion of the transparent substrate; After baking, a transparent conductive thin film and an insulating protective film are formed in this order on a transparent substrate containing this paste by a vacuum film forming method, and then the transparent conductive thin film and insulating protective film on the paste are removed. A method for forming an electrode on a transparent conductive thin film, which comprises connecting a lead wire to this paste by soldering or the like, and finally covering the electrode forming part with a sealing resin. (2) A method for forming electrode terminals on a transparent conductive thin film on a transparent substrate on which a transparent conductive thin film and an insulating protective film are formed, the method comprising: a paste containing a conductive substance in the electrode forming portion of the transparent substrate; After baking, a transparent conductive thin film and an insulating protective film are formed in this order on a transparent substrate containing this paste using a vacuum film forming method, and then ultrasonic soldering is applied to the transparent conductive thin film and insulating protective film on the paste. A method for forming an electrode on a transparent conductive thin film, characterized by applying a soldering iron, performing ultrasonic soldering using a conductive substance to connect lead wires, and finally covering the electrode forming part with a sealing resin.