JPS63294537A - Ec element which decrease leak current - Google Patents

Abstract

PURPOSE:To decrease leak current by forming the tiled element into the structure in which a tantalum oxide layer, i.e., ion conductive layer and/or tungsten oxide layer, i.e., reduction colorable EC layer is interposed between an upper electrode and iridium oxide layer near grooves. CONSTITUTION:An electrode layer is formed over the entire surface of a substrate S and the iridium oxide layer C is formed thereon, following which the two layers in a laminated state are formed with grooves by cutting using a laser or other cutting means. A taking out part F for the upper electrode A and a lower electrode part B as well as a taking out part B1 for the lower electrode connected to the lower electrode are formed and thereafter, the tantalum oxide layer D and the tungsten oxide layer E are formed by another mask. The layers D and E are so formed as to cover the end faces of the lower electrode B and the iridium oxide layer C facing the grooves. The contact of the upper electrode A and the iridium oxide layer C is, therefore, obviated. The leak current is thereby decreased.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to improvements in electrochromic devices.

Below, electrochromic is rEC.

The EC element is abbreviated as rECD.

[Conventional technology]

Electrochromism is a phenomenon in which a reversible electrolytic oxidation or reduction reaction occurs when a voltage is applied, resulting in reversible coloration.Electrochromic (hereinafter abbreviated as EC) substances that exhibit this phenomenon are used to perform voltage manipulation. We created an EC element (hereinafter abbreviated as ECD) that can be colored and decolored by
Attempts to use CDs as light control devices (e.g. anti-glare mirrors) and numeric display devices using 7 segments have been made for more than 20 years. cathode), tungsten dioxide thin film,
An ECD (see Japanese Patent Publication No. 52-46098), which is made by sequentially laminating an insulating film such as sulfur dioxide and an electrode film (anode), is known as an all-solid-state ECD. When a voltage is applied to this ECD, tungsten dioxide The (WOs)ti film is colored blue. After that, when a reverse voltage is applied to this ECD, the blue color of the WO3 thin film disappears and it becomes colorless. The mechanism of this coloring/discoloration has not been elucidated in detail, but W0
It is understood that a small amount of water contained in the thin film and insulating film (ion conductive layer) controls the coloring and decoloring of W Ox. The reaction formula for coloring is estimated as follows.

Cathode side: H, O→H" +0H- WOs +nH" +ne e-→HllWOx (colorless and transparent) (blue) Anode side: OH--1/2 Hz O+1/40x ↑+1/2
e-By the way, at least one of the pair of electrode layers that directly or indirectly sandwich the EC layer must be transparent in order to show the coloring and fading of the ECJi to the outside. Especially transmission type EC
In the case of D, both must be transparent.Currently, transparent electrode materials include SnOx, I
Known materials include NZO, ITO (a mixture of Snow and In80), and ZnO, but these materials have relatively poor transparency and therefore have to be made thin (for this and other reasons). ECDs are commonly formed on a substrate such as a glass plate or a plastic plate;
An example of the structure of D is shown in FIG.

In Figure 3, (A) is the upper electrode, (B) is the lower transparent electrode, (E) is the reduction coloring EC layer (for example, WO2), (
D) shows an ion conductive layer, and (C) shows a reversible electrolytic oxidation layer or an oxidation-colored EC layer (for example, iridium oxide or hydroxide), and basically only the laminated structure of (A) to (B) is used. As described above, these ECDs are formed on the substrate (S).

(R) is an ECD sealing material such as an epoxy resin;
G) is a protective sealing substrate.

By the way, in a conventional ECD, a first FJ on the substrate includes an upper electrode (A) lead-out part (F), a lower electrode (B) separated from it, and a lower electrode lead-out part (B) continuous to the lower electrode. on which an iridium oxide layer (C) is formed.
, tantalum oxide i (D) and tungsten oxide layer (E
) were sequentially deposited using the same mask. Furthermore, the upper electrode (A)
Then, AN was deposited using a separate mask, and at this time, AI! , were brought into contact with the extraction electrode forming portion (F) already formed on the substrate (S).

In addition, the formation of the first layer has conventionally been carried out by (1) once forming an electrode layer on the entire or almost the entire surface of the substrate and then patterning by photoetching, or (2) directly forming the electrode layer. This was done by either mask vapor deposition or mask vapor deposition.

[Problem that the invention seeks to solve]

In the case of the conventional layer structure, the three EC layers (C) to (E) are formed using the same mask, and then the Al (A) layer is vapor-deposited.
Among the EC3 layers, the iridium oxide layer has a relatively low resistance (
C) comes into contact with the lower electrode layer (B) near the groove, and there is a possibility that leakage current between the lower electrode layer (B) and the lower electrode layer (B) through the layer (C) will increase (see FIG. 3).

In addition, in the method for forming the first layer, method (1) requires a complicated process of coating a photoresist → exposing a pattern → patterning the photoresist by developing → etching → cleaning → drying. There were problems in that the manufacturing cost was high and the manufacturing time was long. Also,
In order to narrow the groove between the lead-out part (F) of the upper electrode (A) and the lower electrode (B), a precise mask pattern is required, but it is difficult to create such a mask pattern, and therefore, The problem was that the grooves had to be thicker. Further, there were other problems such as resist unevenness, etching unevenness, and narrow grooves that could not be corrected.

On the other hand, method (2) has the problem that it is not only difficult to form narrow grooves, but also that the lines of the grooves are irregular and the appearance is poor.

[Means for Solving the Problems] Therefore, the present invention provides a method for preventing the upper electrode (A) and the lower electrode (B) from coming into contact with each other in the vicinity of the groove through the iridium II oxide (C). A structure was adopted in which a tantalum oxide layer - ion conductive N (D) and/or a tungsten oxide layer = reduction coloring EC layer (E) were interposed between the upper electrode (A) and the iridium oxide layer (C) in the vicinity.

[Effect]

For example, the structure 0ECD of the present invention can be manufactured as follows. An electrode layer is formed on the entire surface of the substrate, then an iridium oxide layer (C) is formed, and then grooves are formed by cutting the two layers together using a laser or other cutting means, thereby forming an upper electrode (A). Form the extraction part (F), the lower electrode part (B), and the extraction part (B1) of the lower electrode that is continuous with the lower electrode, and then use a separate mask to form the tantalum oxide layer (D) and the tungsten oxide layer (E).
form.

In this case, the material of the layers (D) and (E) is the lower electrode (B
) and the end faces of the iridium oxide layer (C) facing the grooves (exposed to the grooves) are coated. In general,
It is only necessary to widen the opening by shifting the groove-side end of the opening of the mask outward when performing mask vapor deposition.

Next, as the upper electrode (A), Al was placed on (C) above (F゛).
formed in contact with a portion of the layer.

With this structure, the upper electrode (A) and the iridium oxide layer (C) do not come into contact with each other, so the lower electrode 711 (B
) will not increase the leakage current.

Also, the extraction part (F) of the upper electrode (A) and the lower electrode part (B)
It is preferable that the width of the blank (groove) between the Can be made larger. Note that if the width is too narrow, there is a risk of a short circuit between the two, so it is preferable to make the width 30 um or more.

In addition, to take out the electrode, use external wiring (LA) on the end surface of the board.
(Ll) or external wiring (LA) in advance,
(L,) is bonded by attaching a conductive clip (H). If external wiring is to be bonded to the edge of the board, use the wraparound during ITO evaporation to connect the IT to the edge of the board.
It is necessary to form OJi.

The conductive clip is preferably made of a metal that has spring properties, and metals are also preferred because they allow good soldering. Preferred metals that have spring properties include phosphor bronze; etc. are also used. The metal clip may be coated with a relatively soft metal, such as tin, indium, solder, a mixture thereof, or other conductive material, at least on the surface in contact with the extraction part; This is because the metal surface generally has subtle irregularities when viewed under a microscope, and mere pressure contact will not provide the best contact with the extraction part. Furthermore, tin plating on phosphor bronze clips has the advantage of improving corrosion resistance.

Also, since the clip always presses the extraction part against the board, there is no risk of the extraction part coming off from the board even if it is subjected to a hot water immersion test. However, there is a risk of damaging the extraction part when attaching the clip. Therefore, it is preferable that the take-out part itself be made of a strong ITo or other oxide-based electrode material. However, if the attachment is done with great care, the risk of damage can be eliminated.

The conductive clip may also serve as a shielding material or decorative material for the peripheral area of the ECD, especially in the case of an anti-glare mirror (the amount of reflected light is electrically controlled) where the ECD is viewed from the board side. Since it is aesthetically preferable to increase the area of the display part and make the peripheral part thinner, it is advantageous to use it as a lid.

If the clip is made of a material that can be soldered, you can just solder it when connecting external wiring to the clip, but if the clip is made of metal, use a conductive material instead of soldering. Connections may be made by adhesive, crimping or clamping.

It is preferable to connect the external wiring to the clip, if the sustain is soldered, before attaching it to the ECD, so that the ECD is not exposed to the heat of soldering and there is no risk of damage due to heat.

The connection between the external wiring and the clip is physically and chemically weak, so it is preferable to seal it.
It is particularly preferable to carry out the sealing process simultaneously with the sealing process, since a separate sealing process is not required.

On the other hand, the Mi layer structure of the ECD in the present invention is not particularly limited, but the structure of the solid-state ECD includes, for example, ■ electrode Ji/EC layer/ion conductive layer/electrode layer. 4-layer structure, ■ Electrode layer / reduction colored EC layer / ion conductive layer / reversible electrolytic oxidation layer or oxidation colored ECC
A five-layer structure such as layered electrode layers can be mentioned.

Examples of the material of the transparent electrode include SnO□, In201
, ITO, etc. are used. Such an electrode layer is -S
It is formed using vacuum thin film forming techniques such as vacuum evaporation, ion blating, and sputtering. (Reduction coloring property)
As the EC layer, WO, Mob, etc. are generally used.

As the ion conductive layer, for example, silicon oxide, tantalum oxide, titanium oxide, aluminum oxide, niobium oxide, zirconium oxide, hafnium oxide, lanthanum oxide, magnesium fluoride, etc. are used. Due to the manufacturing method, these thin films of materials are insulators for electrons, but they are insulators for protons (
It is a good conductor for H') and hydroxy ions (OH-). Cations are required for the coloring and decoloring reaction of E (4J), and it is necessary to contain H3 ions and Li3 ions in the EC layer and other parts. It is sufficient that H9 ions are generated in the process, and therefore water may be included in place of H° ions.A very small amount of this water is sufficient, and often even moisture that naturally enters from the atmosphere will discolor and discolor. .

The EC layer and the ion conductive layer may be placed either side up or down. Furthermore, a reversible electrolytic oxidation layer (or oxidation-colored EC layer) or a catalyst layer may be provided with an ion ring interposed between the EC layer and the EC layer.

Such layers include, for example, iridium oxide or hydroxide, nickel, chromium, vanadium, ruthenium, rhodium, and the like. These substances may be dispersed in the ion conductive layer or the transparent electrode, or may be dispersed therein.

The opaque electrode layer may also serve as a reflective layer, and for example, metals such as gold, silver, aluminum, chromium, tin, zinc, nickel, ruthenium, rhodium, and stainless steel are used.

〔Example! ]

FIG. 1 is a sectional view of the ECD of this embodiment.

(1) An ITO film is formed on a glass substrate (S), and then an iridium oxide layer (C) containing tin oxide is formed slightly inside the peripheral edge of the glass substrate. Next, a YAG laser (wavelength 1.
064 μm; Q switch lKH2: power 100=1
000 mW) while scanning at a scanning speed of 1 to 50 m.
By moving this at a rate of ff1/sec, a groove was formed between the upper electrode lead-out part (F) and the lower electrode part (B).

(2) 8th Next, tantalum oxide Ji (D) and tungsten oxide layer (E) were sequentially formed to cover the iridium oxide layer (C) and the end face portion facing the groove of the lower electrode (B).

(3) AN was formed thereon as the upper electrode (A) so as to be in contact with the remainder (C1) of the layer (C) on the lead-out portion (F) of the upper electrode. Since the (C,) layer has a relatively low resistance, conduction between (A) and (F) can be maintained even if (c+) FJ is interposed between (A) and (F).

(4) First, external wiring (LA) and (Le) were bonded to the upper electrode extraction side and the lower electrode extraction side of the end face of the glass substrate (S) (where ITO goes around), respectively. .

(5) Finally, the element was sealed with an epoxy resin sealant (R), and the sealing substrate (G) was adhered to complete the sealing, and the ECD of this example was manufactured.

Coloring voltage (+1.3
5V), the wavelength 6 incident from the substrate (S)
The reflectance decreased to 15% for 33 nm light (L) after 10 seconds), and this reflectance was maintained for a while even after the voltage application was stopped. When a decoloring voltage (-1.35 V) was applied this time, the reflectance recovered to 65% (after 10 seconds).

Therefore, the ECD of this embodiment is useful as an anti-glare mirror for automobiles and other vehicles, and when a strong light from a car approaching from behind hits the mirror, applying a voltage will reduce the reflectance.
The driver is no longer dazzling (Example 2) FIG. 2 is a sectional view of the ECD of this example.

(1) An ITO film is formed on the glass substrate (S), and then an iridium oxide layer (C) containing tin oxide is formed slightly inside the peripheral edge of the glass substrate.The luminous flux diameter at the zero-order irradiation position is 1 ~1000μ■ YAG laser (wavelength 1.
064, us; Q switch IKII2: power 10
Scan speed 1-5 while irradiating 0-100100O
By moving this for 0-7 seconds, a groove was formed between the upper electrode lead-out part (F) and the lower electrode part (B).

(2) Next, the tantalum oxide layer (D) and the tungsten oxide layer (E) are connected to the iridium oxide layer (C) and the lower electrode (B).
) were formed in order so as to cover the end faces facing the grooves.

(3) Al was formed thereon as an upper electrode (A) so as to be in contact with the remainder (C1) of the layer (C) on the lead-out portion (F) of the upper electrode.

(4) In advance, connect the external wiring (La) and (Lm) with solder, conductive adhesive, crimping, or clamping, and attach the phosphor bronze clip (H) to the lower electrode extraction part (Fo).
and the lower electrode outlet (B,).

(5) Finally, seal the element with an epoxy resin sealant (R) and adhere the sealing substrate (G) to complete the sealing,
An ECD of this example was manufactured.

A coloring voltage (+1.
When a voltage of 35V) is applied, the reflectance decreases to 15% for light (L) with a wavelength of 633n− incident from the substrate (S) (after 10 seconds), and this reflectance remains for a while even after the voltage application is stopped. (It was maintained. This time, when a decoloring voltage (-1.35 V) was applied, the reflectance similarly recovered to 65% (after 10 seconds).

Therefore, the ECD of this embodiment is useful as an anti-glare mirror for automobiles and other vehicles, and when a strong light from a car approaching from behind hits the mirror, the driver will not be dazzled by applying a voltage to reduce the reflectance.

〔Effect of the invention〕

As described above, according to the present invention, since the upper electrode and the lower electrode of the ECD have a layered structure in which they are reliably separated, there is no risk of short circuit, and leakage current can be reduced.

In addition, since patterning is done by laser cutting, it is much simpler than patterning by photo-etching, and the manufacturing cost of the ECD is low.Furthermore, thin grooves can be easily formed, so the display area can be made larger. become.

Therefore, if an ECD is created using the electrodes manufactured by the method of the present invention and this ECD is used, for example, in an anti-glare mirror that can change the amount of light, the peripheral area of the display part can be made relatively small. This results in an excellent aesthetic appearance.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of an ECD according to Example 1 of the present invention. FIG. 2 is a schematic cross-sectional view of an ECD according to Example 2 of the present invention. FIG. 3 is a schematic cross-sectional view of a conventional ECD. [Explanation of symbols of main parts] A... Upper electrode B... Lower electrode B,... Lower electrode extraction part E... Reduction coloring ECI! ! l or WOs layer F...
Upper electrode lead-out portion H...Conductive clip L^, L-layer...External wiring C...Oxidation colored EC layer or iridium oxide layer CI.
・Remains of 0 layer

Claims (2)

[Claims] (1) At least an electrochromic layer and an upper electrode are laminated on a substrate on which an electrode extraction portion of the upper electrode is formed, and a lower electrode and an electrode extraction portion of the lower electrode continuous to the lower electrode are formed separated from the electrode extraction portion of the upper electrode. An electrochromic device characterized in that an upper electrode layer and a lower electrode layer have a layered structure that prevents short-circuiting, thereby reducing leakage current. (2) The electrochromic device according to claim 1, wherein the electrode extraction portion of the upper electrode and the lower electrode are separated by laser cutting.