JPS62182725A - Production of electrochromic display element with lead terminal - Google Patents

Abstract

PURPOSE:To obtain a sharp display having a high coloring density by forming a metallic plating layer on the transparent conductive film in the lead terminal attaching part of a display electrode substrate without staining the content in an electrochromic display element in the stage of the parts of said element. CONSTITUTION:A protective film 8 consisting of an SiO2 film is formed by forming the transparent conductive film 1b consisting of ITO on a transparent glass substrate 1a, patterning the same to form the display electrode substrate 1 and masking 31 the peripheral edge thereof. After the mask 31 is removed, a photoresist film 32 is formed on a protective film 8 and a mask 33 consisting of a self-adhesive tape is disposed thereto; thereafter, a plating layer 5 is formed on the transparent conductive film 1b in the peripheral edge part of the display electrode substrate 1. Since plating is executed in the stage before the formation of the electrochromic material layer 7 on the display electrode substrate 1, the staining of the electrochromic material by a plating bath and resist film is obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing an electrochromic display element with lead terminals.

[Conventional technology]

In order to cause a coloring reaction in the electrochromic substance of the display electrode of the electrochromic display element, it is necessary to supply electricity to the electrochromic display element from an external driving power source.

The driving power source and the electrochromic display element are generally connected by attaching lead terminals to the display electrode substrate.

The lead terminals are attached to the display electrode side of the display electrode substrate by attaching the lead terminals to the holding portions 4a as shown in FIG.
The end of the display electrode substrate 1 is inserted between the upper piece 4al and the lower piece 4a2, and the end of the display electrode substrate 1 is sandwiched by the restoring force of the upper piece 4a1 and the T piece 4a2 of the reflection section 4a. Then, conductive paste (not shown) is applied to fill the gap between the lead terminals 4 and the display electrode substrate 1, and a hardening liquid type (1) @ (not shown) is applied on top of the conductive paste (not shown). The lead terminals 4 were fixed to the display electrode substrate 1 by curing the resin (for example, see Utility Model Application No. 124090/1983).

[Problem that the invention seeks to solve]

However, as described above, the holding portion 4a of the lead terminal 4
When the ends of the display electrode substrate 1 are directly sandwiched between the electrodes, the electrical connection between the lead terminals 4 and the electrochromic display element is as follows.
The contact resistance is large because contact is made between the holding part 4a of the lead terminal 4 and the transparent conductive film 1b of the display electrode substrate 1, that is, a metal oxide film such as an ITO (indium tin oxide) film or a tin oxide film. Therefore, there was a problem in that the amount of electricity injected into the electrochromic material was reduced, and the color development of the electrochromic material was reduced, making it impossible to obtain a clear display.

Therefore, by providing a metal plating layer on the transparent conductive film lb of the lead terminal attachment part of the display electrode board 1 and bringing the lead terminal 4 into contact with the lead terminal 4, the lead terminal 4 and the display electrode board 1 are connected. It is possible to reduce the contact resistance of

By the way, various methods can be considered for providing a metal plating layer on the transparent conductive film lb at the lead terminal attachment portion of the display electrode substrate 1 as described above, but there are several methods that can be used for the electrochromic display element, which has a specific structure. On the other hand, if plating is carried out according to the concept traditionally adopted in other fields, problems may occur in terms of quality or efficiency, and good results may not necessarily be obtained. There is a problem.

For example, when plating is attempted after the display electrode is fabricated, a resist film must be formed on at least the electrochromic material layer to prevent element contents such as electrochromic material from being damaged by the plating bath. First, as a result, the electrochromic material is partially contaminated by the resist film, causing striped non-coloring areas to appear during coloring, resulting in a reduction in display quality.

In addition, when plating the lead terminal attachment part of the display electrode board after assembling an electrochromic display element, although it has certain effects such as not contaminating the element contents such as electrochromic substances, plating may cover unnecessary parts. Therefore, regardless of the above-mentioned problems, plating at the component stage,
There is a request to form a gold mud plating layer on the transparent conductive film of the lead terminal mounting portion of the display electrode substrate.

[Means for solving problems]

In view of these circumstances, the present invention provides metal plating on the transparent conductive film of the lead terminal mounting portion of the display electrode substrate at the component level of the electrochromic display element and without contaminating the electrochromic material. As a result of various studies conducted to find a method to do this, it was discovered that the above-mentioned object can be easily achieved when plating is performed at the stage of manufacturing the display electrode, and the present invention has been completed.

That is, a protective film for protecting a transparent conductive film such as silicon dioxide (S i 02 ) is formed on the display electrode substrate except for the peripheral edge of the display electrode substrate, and a photoresist film is formed on the protective film. , after covering the photoresist film with a mask,
Metal plating is applied to the transparent conductive film at least on the lead terminal mounting area on the display electrode side of the peripheral edge of the display electrode substrate, and after removing the mask,
When manufacturing a display electrode according to a conventional method, a metal plating layer is coated on the transparent conductive film at least at the lead terminal attachment part on the display electrode side of the display electrode substrate at the component stage and without contaminating the electrochromic substance. This made it possible to reduce the contact resistance between the lead terminals and the display electrode substrate.

” Transparent conductive film on the lead terminal attachment part of the dual display pole -L
Both electroplating and chemical plating can be used for plating. As the plating metal, for example, nickel, tin, gold, solder (lead-tin alloy, etc.) is used. In addition, due to compatibility with the constituent metals of the lead terminal, the plating layer may have a multilayer structure of two or more layers, for example, by applying nickel plating on the transparent conductive film and then applying gold sawdust. .

As the transparent substrate of the display electrode substrate, for example, a transparent glass plate or a transparent plastic plate made of polyester, polysulfon, etc. is used. Furthermore, an undercoat of silicon dioxide may be applied to the transparent glass plate before forming the transparent conductive film. As the transparent conductive film, for example, ITO
A conductive transparent metal oxide film such as (indium oxide) or tin oxide is used. Further, as a protective film for the transparent conductive film, silicon dioxide (S i 02
) film, magnesium fluoride (MgF2) film, etc., and for the photoresist film, for example, phenol novolac resin or the like is used.

The assembly of the electrochromic display element using the display electrode substrate in which the metal plating layer is formed on the transparent conductive film of the lead terminal attachment part as described above is carried out by the method that has been used since then. After assembling the electrochromic display element and attaching the lead terminals,
The lead terminal can be mounted by welding or brazing the lower piece of the lead terminal clamping part to the metal plating layer to fix the lead terminal to the indicator electrode board, or by fixing the lead terminal to the indicator electrode board with resin. Improved stability.

Note that the display electrode board is usually provided with a lead terminal mounting part for the opposing electrode in the same way as the lead terminal mounting part for the display electrode side. In the present invention, the part provided with the metal plating layer is at least the lead terminal attachment part on the display electrode side because the contact resistance between the lead terminal and the display electrode substrate is large on the display electrode side. As mentioned above, problems such as not being able to obtain a clear display occur, and by resolving these problems a remarkable effect can be achieved. At the level of contact resistance with the conductor film, the effect will not be as noticeable as on the display electrode side, and even if the effect is slight,
This is because the overall color density is only slightly reduced. However, it goes without saying that it is better to provide a gold plating layer on the lead terminal mounting portion of the counter-polar example.

〔Example〕

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

First, the production of the display electrode will be explained based on FIG. a)), the peripheral edge of this display electrode substrate 1 (this peripheral edge is the part that is outside the spacer when the electrochromic display element is assembled, and the transparent conductive film is formed on this peripheral edge) A protective film 8 consisting of a 5i02 film having a thickness of 5000 mm was formed on the display electrode substrate 1 except for the periphery (see FIG. 1(b)). ). After removing the mask 31, a 3 μm thick phenol novolac resin photoresist film 32 is formed on the protective film 8 (see FIG. 1C), and a mask made of adhesive tape is placed on the resist film 32. 33, the transparent conductive film 1 on the periphery of the display electrode substrate l is coated with chemical nickel plating.
A nickel plating layer 5 with a thickness of 1 μm was formed on b (
(See Figure 1(d)). Plating bath is nickel sulfate 20g/
l, sodium hypophosphite 10 p/e, lactic acid 3 g/
e, sodium citrate 5g/β, and sodium acetate 5g/l, and the pH was adjusted to 5. Plating was carried out at a temperature of 50° C. and a plating time of 30 minutes.

After removing the mask 33, exposing, developing and rinsing,
After photoresist (see figure (e)), the protective film 8 on the transparent conductive film b is partially removed by dry etching using Freon (trade name)/oxygen plasma (see figure 1 (f)), and then plated. After applying a mask 34 to the peripheral edge of the display electrode substrate 1 including the layer 5, tungsten oxide (WO3) was attached to form an electrochromic material layer 7 having a thickness of 2500 B (see FIG. 1(g)). ), then remove the resist 1 to film 32 and mask 34 on the protective film 8, and plate I on the transparent conductive film lb at the lead terminal attachment part of the display electrode substrate 1.
A display electrode 9 having a diameter of '55 was produced (see FIG. 1(h)).

According to the method described above, since electrochromic material is plated in step iii of forming the electrochromic material layer 7 on the display electrode substrate l, the electrochromic material is not contaminated by the plating bath or the resist film.

Using the display electrode 9 produced as described above, an electrochromic display element is assembled by this method, and the lead n1 and the lead 4 are attached to the lead terminal attaching portion of the display electrode substrate 1 so that the clamping portion 4a of the lead is attached to the plated layer 5. In order to further improve the installation stability, apply conductive paste to the part where the lead terminal 4 is attached, and then apply epoxy resin on top of it, and then attach the lead terminal 4 to the display electrode board l. Fixed.

In the electrochromic display element with lead terminals manufactured in this manner, the contact resistance between the lead terminals 4 and the display electrode substrate l was 0.3Ω, which was lower than that of conventional products. Note that, as shown in FIG. 9, the lower piece 4a2 of the clamping part 4a of the lead terminal 4 on the display electrode side is brought into direct contact with the transparent conductive film (1) of the display electrode substrate 1. In an electrochromic display element with a lead terminal (that is, an electrochromic display element with a single terminal in which the safe plating layer 5 of the present invention is not provided on the transparent conductive film lb at the lead terminal attachment part of the display electrode substrate l), The contact resistance between the terminal 4 and the display electrode substrate 1 was 2Ω. When a voltage was applied to these two types of electrochromic display elements with lead terminals for 1,0,045 seconds,
The product of the present invention had a higher coloring density of the electrochromic material layer than the conventional product, and was able to provide clearer display.

The state of lead terminal attachment on the display electrode side of the electrochromic display element with lead terminals manufactured as described above is shown in Figs. 2 and 3, and the overall schematic perspective view and schematic plan view are shown in Figs. 4 and 5. The electrochromic display element part is shown in Fig. 6, the enlarged plan view of the display part is shown in Fig. 7, and the lead terminal attachment part of the display electrode substrate after the electrochromic display element is assembled is shown schematically in Fig. 8. Shown below.

First, these will be explained based on FIGS. 2 and 3. In the figures, 1 is a display electrode substrate, and a transparent conductive film ib of [TO (indium tin oxide)] is formed on a transparent glass plate 2a. Although not shown in FIGS. 2 and 3, the electrochromic material layer is provided on the transparent conductive film 1b of the display electrode substrate 1 so as to form a display pattern with an aggregate of a plurality of segments 1-. , thereby forming a display pole.

Reference numeral 2 designates a counter electrode substrate, and this counter electrode substrate 2 also has a transparent conductive film 2b of ITO formed on a glass plate 2a, similar to the display electrode substrate 1, and is not shown in FIGS. No, but
A counter polar material rR layer is provided on the transparent conductive film 2b, thereby forming a counter pole. And 3 is a spacer made of polyester.

4 is a lead terminal on the display electrode side, and 5 is a nickel plating layer formed on the transparent conductive film lb at the part j (=the number of lead terminals on the display electrode substrate 1 at the display electrode manufacturing stage as described above). Then, the lead terminal 4 is inserted into the display electrode substrate 1 by fitting the holding portion 4a into the end portion of the display electrode substrate 1 so that the lower piece 4a2 of the holding portion 4a is in contact with the plating layer 5.
Apply conductive paste to the part where the lead terminal 4 is attached, and then apply epoxy column 1 resin from above to fix the lead terminal 4 to the display electrode substrate 1. .

A plurality of lead terminals 4 on the display electrode side as described above are attached along both ends of the display electrode substrate 1, as shown in FIGS. 4 and 5. Specifically, a necessary number of leads n1 and 4 are attached to the display substrate l according to the number of segments constituting one display pattern and the number of display patterns. In other words, the electrochromic material layer 7 is
As shown in detail in FIG. 7, the display pattern is formed by an aggregate of segments 78 to 7g, and the transparent conductive film 1b is etched to drive each of the segments 7a to 7g independently. are appropriately cut to form independent conductive paths 15a to 15g. The lead terminals 4 each constitute an independent conductive path, each transparent conductor 15! each segment 7 of electrochromic material is attached to the display electrode substrate 1 in such a manner that it can supply electricity to the
8 to 7g can be colored and decolored independently. In addition, 6 in FIGS. 4 and 5 is a lead terminal of an example of a counter electrode, and similarly to the lead terminal 4 of the display electrode side, this lead terminal 6 of the counter electrode side also has its clamping portion 6a connected to the display electrode substrate 1. It is attached to the display electrode substrate l by fitting it into the end of the display electrode substrate l. However, the lead terminal 6 of the opposing electrode and the lead terminal 4 of the display electrode adjacent thereto are insulated by etching into the transparent conductive film 1b (see Fig. 5).
, and the lead terminal 6 on the opposite pole and the lead terminal 4 on the display pole side are electrically insulated.

FIG. 6 is a cross-sectional view schematically showing the electrochromic display element part of the electrochromic display element with lead terminals of the present invention. forming a film 1b,
A display electrode 9 is formed by forming an electrochromic material layer 7 on the transparent conductive film lb of the display electrode substrate 1.

Although not shown, as mentioned above, 5iQ2 was applied on the transparent glass t&la before forming the transparent conductive film 1b.
You may also apply an undercoat. And the above transparent conductive 1! A protective film 8 of 5i02 is formed in a portion of t'lb where the electrochromic substance N7 is not formed. Note that the electrochromic material layer 7 is the fourth
5 and 7, the transparent conductive material (1)'J1b is appropriately cut by etching, and each segment 7a to 7g of the electrochromic material (see FIG. 7) is formed into segments. ) are formed with independent conductive paths 15a to 15g, respectively, so that they can be driven independently.

Examples of electrochromic substances include Tsuho, Tangfu oxide 7'no (WO3), iridium oxide (Ir02),
Transition total oxides such as molybdenum (MoO2), Prussian blue, tetrathiafulvalene derivatives, and viologen derivatives are used, but in this embodiment, tungsten oxide is used as described above.

The counter homopolar substrate 2 is formed by forming a transparent conductive film 2b of ITO on a transparent glass plate 2a, and iron tungstate (F e2 (WO4) 3 ) is used as a counter homopolar material on the transparent conductive film 2b. The counter electrode 11 is formed by forming a counter electrode material layer 10 made of a conductive additive and a binder. Note that this counter electrode substrate 2 does not require transparency like the display electrode substrate 1, so it may be a metal plate, or it may be a ceramic plate or a plastic plate as long as a conductive part corresponding to the transparent conductive film 2b is provided. The substrate may be composed of a plate.

Reference numeral 12 denotes a background material disposed between the electrochromic material layer 7 of the display electrode 9 and the counter electrode material [10] of the counter electrode (1). 13 is a liquid electrolytic IW material prepared by dissolving 1.0 mol/1/8 lithium perchlorate in propylene carbonate.

The spacer 3 has a ring shape, and its upper and lower surfaces are fixed to the display electrode substrate 1 and the counter electrode substrate 2 with adhesive such as epoxy resin, respectively, to insulate the display electrode substrate 1 and the counter electrode substrate 2. At the same time, the spacer 3, the display electrode substrate 1, and the counter electrode substrate 2 form a cell for accommodating element contents such as the electrolyte 13, the electrochromic material layer 7, the counter electrode material layer 10, and the background material 12. are doing.

FIG. 7 schematically shows the display part, and is an enlarged plan view of the display electrode viewed from the side where the electrochromic material N7 is provided. It is provided so as to form a display pattern consisting of. Segments 15a to 15g of the above-mentioned electrochromic substance) 7a to 7g are conductive parts through which electricity necessary to cause a coloring reaction are passed, and these conductive parts 15a to 15g were formed by appropriately cutting the transparent conductive film 1b. This conductive portion 15a~
The 15g resistance is adjusted to be inversely proportional to the surface resistance of each segment of electrochromic material, 78-7g. Insulating parts 16a to 16h are provided to prevent short-circuiting of the conductive parts 15a to 15g, and are provided by partially removing the transparent conductive film 1b by etching. Note that 16i and 163 are insulating barriers provided to prevent current from flowing too quickly in the segments 7a and 7d, resulting in a difference in response speed between the segments 7a and 7d. As described above, the lead terminal mounting portion on the display electrode side of the display electrode substrate 1 is connected to the number of electrochromic segments constituting the display pattern.
In other words, a number (1) 1i1 is provided corresponding to the number of conductive parts made of the transparent conductive film 1b, and further according to the number of display patterns, and lead terminals are attached to the parts.

FIG. 8 schematically shows the lead terminal attachment part of the display electrode substrate of the electrochromic display element, and is a plan view of the electrochromic display element viewed from the opposite pole side, and in the figure, 14 is the display pole side. The surface layer of the lead terminal attachment part is composed of the nickel plating layer 5 formed on the transparent conductive film lb as described above, and as is clear from FIG. A large number of lead terminal attaching parts 14 are provided depending on the number of segments constituting the display pattern and the size of the display pattern. Reference numeral 17 denotes an insulating part between the lead terminal attachment parts 14, which is formed by partially removing the transparent conductive film 1b by etching, and corresponds to the insulating part in FIG. 7. Note that 18 is a lead terminal mounting portion on the opposite electrode side.

In addition, in the example, the plating layer was provided by chemical plating and nickel was used as the plating metal, but even if electroplating is used instead of chemical plating, or if a metal other than nickel is used, the plating layer can be applied. The same effect as in the example is produced.

〔Effect of the invention〕

As explained above, according to the present invention, at the component stage of an electrochromic display element, without contaminating the element contents such as an electrochromic substance, the transparent conductive film of the lead terminal attachment part of the display electrode substrate is coated. It was possible to form a gold mud plating layer, thereby reducing the contact resistance between the lead terminals and the display electrode substrate, and realizing a clear display with high color density.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the process of manufacturing a display electrode having a metal plating layer on a transparent conductive film of a lead terminal attaching portion of a display electrode substrate in the present invention. 2 to 7 show an example of an electrochromic display element with lead terminals according to the present invention, FIG. 2 is a partially enlarged cross-sectional view showing how the lead terminals on the display electrode side are attached, and FIG. 3 is a display FIG. 4 is a schematic perspective view, FIG. 5 is a schematic plan view, FIG. 6 is a cross-sectional view of the electrochromic display element, and FIG. FIG. 7 is an enlarged plan view schematically showing the display portion, and is a view of the display electrode viewed from the side on which the electrochromic material layer is provided. FIG. 8 is a plan view schematically showing the lead terminal mounting portion of the display electrode substrate of the electrochromic display element, and is a view of the electrochromic display element viewed from the opposite electrode side. FIG. 9 is a partially enlarged cross-sectional view showing how lead terminals on the display electrode side of a conventional electrochromic display element with lead terminals are attached. 1...Display electrode substrate, ■b...Transparent conductive film, 4...
・Lead terminal on display electrode side, 5... Metal plating layer, 7... Electrochromic material layer, 8... Protective film, 9... Display electrode,
(1)...Counter electrode, 13...Electrolyte, 14...
Display electrode side lead terminal attachment part, 32... Photoresist film, 33. 34... Mask Figure 1 (a) b (d) (g) 2nd recess Figure 4 Figure 6 Factor 8 Figure 8 90

Claims (1)

[Claims] (1) In manufacturing an electrochromic display element with lead terminals, which is formed by attaching lead terminals to the display electrode substrate of an electrochromic display element equipped with a display electrode, a counter electrode, and an electrolyte, a transparent conductive film is provided on a transparent substrate, and a transparent conductive film is provided on a transparent substrate. A transparent conductive film is patterned to form a display electrode substrate, a protective film for protecting the transparent conductive film is formed on the display electrode substrate except for the peripheral portion of the display electrode substrate, and a photoresist film is formed on the protective film. After forming the photoresist film and covering the photoresist film with a mask, metal plating is applied to the transparent conductive film on at least the lead terminal mounting portion on the display electrode side among the lead terminal mounting portions on the peripheral edge of the display electrode substrate, and after removing the mask. , the photoresist film is partially removed by exposure, development, and rinsing, and the protective film on the transparent conductive film is partially removed by dry etching to expose a part of the transparent conductive film, and the peripheral edge of the display electrode substrate is removed. After masking the area, an electrochromic material layer is formed, and then the photoresist film and the mask on the peripheral area are removed to form a display electrode having a metal plating layer on at least the lead terminal mounting area on the display electrode side of the display electrode substrate. 1. A method for producing an electrochromic display element with lead terminals.