JPS62182724A - Production of electrochromic display element with lead terminal - Google Patents

Abstract

PURPOSE:To eliminate the need for a plating power source from the outside by injecting electricity to an electrochromic display element and subjecting a transparent conductive film in the lead terminal attaching part of a display electrode substrate to electroplating using the injected electricity as a plating power source. CONSTITUTION:30mC/cm<2> electricity is preliminarily injected to an electrochromic display element of which the display part has two patterns by using a testing terminal. The electrochromic display element injected with electricity is immersed in a plating bath 21 and nickel plating is executed by utilizing the quantity of the electricity injected to the electrochromic display element. The electrochromic display element has about 0.4V voltage by the quantity of the electricity injected thereto and the nickel ions in a plating bath deposit as metallic nickel on the transparent conductive film in the lead terminal attaching part on the display electrode side of the display electrode substrate 1 from right after the immersion of the element 20 into the bath 21.

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

The lead terminals on the display electrode side are attached to the display electrode substrate as shown in FIG.
Inserting the end of one side of the display electrode substrate 1 between the upper piece 4a1 and the lower piece 4a2, and sandwiching the end of the display electrode substrate 1 by the restoring force of the upper piece 4a1 and the lower piece 4a2 of the clamping part 4a. Then, a 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 resin (not shown) is applied on top of the conductive paste (not shown) to harden the resin. The lead terminals 4 were fixed to the display electrode substrate 1 using the following method (for example, 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 directly fixing the end of the display electrode substrate 1, the electrical connection between the lead terminal 4 and the electrochromic display element 1t-,
N represents the sandwiching portion 4a of the lead terminal 4 and the transparent conductive film 1b of the display electrode substrate 1, that is, the ITO (indium tin oxide) film;
Since this is done through contact with a metal oxide film such as a tin oxide film, the contact resistance is large, and therefore the amount of electricity injected into the electrochromic material is reduced, resulting in less coloring of the electrochromic material and a clearer color. There was a problem that the display could not be obtained.

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

By the way, in providing the metal plating layer on the transparent 4-electrode film of the lead terminal attachment part of the display electrode substrate as described above,
Various methods can be considered, but simply applying the plating methods conventionally used in other fields to electrochromic display elements, which have a specific structure, may cause quality problems. , problems occur in terms of efficiency, and good results are not necessarily obtained.

For example, if you try to form a plating layer by chemical plating, will it be a transparent conductor? ! ! Since the film is not a metal body, activation treatment is essential, but it is difficult to selectively activate only the transparent conductive film, and as a result, the transparent conductive film on the lead terminal attachment part and the adjacent lead terminal attachment part are difficult to selectively activate. The insulating parts provided between the transparent conductive films of However, there is a problem that it is not possible to do this by simply applying plating methods that have been conventionally used in other fields.
There is a problem in that the cathode of the plating power supply must be attached to each of the large number of lead terminal attachment parts, which is very time-consuming.

[Means for solving problems]

Therefore, the inventors of the present invention have conducted various studies in order to find a method for easily and efficiently repairing the electrochromic display element by taking advantage of the characteristics of the electrochromic display element. When electroplating is performed on the transparent conductive film of the lead terminal attachment part of the display electrode board using the electricity that has entered the display element as the plating power source, an external plating power source is not required, and therefore it is possible to mount a large number of lead terminals. Plating can be performed without connecting the cathode of the plating power supply to the parts, and it is possible to selectively plate the transparent 4-electrode film on the lead terminal attachment part, allowing easy and efficient plating to be applied to the desired parts. The inventors have discovered that it is possible to form the following, and have completed the invention set forth in claim 1.

The plating thickness formed on the transparent conductive film is 0.1μ.
m or more, preferably 0.5 μm or more, and even when electroplating is performed using the electricity injected into the electrochromic display element as a plating power source as described above, it is possible to perform plating with a thickness of about 1 μm. However, in order to more reliably lower the contact resistance between the lead terminal and the display electrode substrate, it is desirable to form the plating layer more j7<.

However, the amount of plating that can be formed on the transparent conductive film of the lead terminal attachment part of the display electrode substrate by the above method is limited by the amount of electricity injected into the electrochromic display element, and the amount of electricity that can be injected into the electrochromic display element is limited. The amount is limited by the amount of electrochromic material in the display electrode, so in order to thicken the plating layer, it is necessary to form a thick electrochromic material layer.
Electrochromic material layers are mainly formed by vapor deposition, and in order to form a thick electrochromic material, a long time is required for vapor deposition, which causes problems in the productivity of electrochromic display devices.

Therefore, as a result of further research, the inventors of the present invention found that the electricity injected into the electrochromic display element as described above was used as a plating power source, and a transparent conductive film was formed on the lead terminal attachment part on the display electrode side of the display electrode substrate by electroplating. When forming a second plating layer by chemical plating on the plating layer after forming the first plating layer thereon, since the part to be plated is a metal body, activation is not necessary. ,
We have discovered scales that can easily and efficiently form a plating layer of a desired thickness by taking advantage of the characteristics of chemical plating that chemical plating can be applied selectively to only desired areas and that it is easy to form a thick layer. The invention described in claim 2 has been completed.

Examples of plating metals include nickel, tin, gold, and solder (
Lead-tin alloys, etc.) are used.

Then, using the formed plating layer, the lower piece of the clamping part of the lead terminal is connected or soldered to the above plating layer to fix the lead terminal to the display electrode substrate, or the lead terminal is fixed with resin. ☆If the H31 terminal is fixed to the display electrode board, the installation stability of the lead terminal will be improved.

Furthermore, in consideration of compatibility with the constituent metals of the lead terminal, a different metal may be further plated on the formed plating layer.

In addition, although the present invention requires that a metal plating layer be formed on the transparent electrolytic film on the lead terminal mounting portion on the display electrode side, a plating layer is also formed on the lead terminal mounting portion on the counter electrode side by other means. Of course, it is also possible to form
It is not excluded that a metal layer may also be formed on the lead terminal mounting portion on the opposite pole side.

〔Example〕

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

Example 1 Electricity of 30 mC/cd was injected into an electrochromic display element whose display portion had two patterns (2D, D=Digit) using test terminals in advance.

The electrochromic display element injected with electricity as described above was immersed in a plating bath 21 as shown in FIG. 1, and nickel plating was performed using the amount of electricity injected into the electrochromic display element 20. . The electrochromic display element has a voltage of about 0.4V depending on the amount of electricity injected, and immediately after the electrochromic display element 20 is immersed in the plating bath 21, nickel ions in the plating bath are applied to the display electrode of the display electrode substrate 1. Metallic nickel was deposited on the transparent conductive film of the side lead terminal attachment part, and a nickel plating layer with a thickness of 0.5 μm was formed in 50 minutes of plating time. The details of the electrochromic display element are shown in FIG. 6, and the details of the lead terminal mounting portion of the display electrode substrate are shown in FIG. 8, and these will be explained in detail later.

Plating bath is nickel sulfate 300g/L, nickel chloride/L
z45g/1, boric acid 45g/L',
Adjusted to pH 5.

After applying second Kel plating to the lead terminal attachment part on the display electrode side of the display electrode board as described above, attach the lead terminal so that the lower piece of the clamping part of the lead terminal contacts the nickel plating layer. In order to further increase the stability of the mounting on the display electrode substrate, conductive paste was applied to the area where the lead terminals were attached, and then epoxy resin was applied on top of that to fix the lead terminals on the display electrode substrate.

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. As shown in FIG. 9, the lower piece 4a2 of the holding part 4a of the lead terminal 1 on the display electrode side is connected to the transparent conductor 1f of the display electrode substrate 1. T! A conventional electrochromic display element with lead terminals in direct contact with 1b (i.e.,
In an electrochromic display element with lead terminals in which the metal plating layer 5 of the present invention is not provided on the transparent groove T1 film of the lead terminal mounting portion of the display electrode substrate 1, the contact between the lead terminals 4 and the display electrode substrate 1 is The resistance was 2Ω. And these two types of electrochrome with lead terminals <'
1 for each of the 7 display elements. When a voltage of OV was applied for 0.5 seconds, the electrochromic display element of the present invention showed a higher electrochromicity than conventional products.

The coloring density of the material layer was high (and a clearer display was possible).

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. 6 is a cross-sectional view of the electrochromic display element, FIG. 7 is an enlarged plan view of the display portion, and FIG. 8 is a schematic diagram of the lead terminal mounting portion of the display electrode substrate. To explain based on FIGS. 2 and 3, in the figure, ■ is the display electrode substrate, and the transparent glass 1
A transparent conductive film 1b of ITO (indium, easily oxidized) is formed on the display electrode substrate 1a, and although not shown in FIGS. A plurality of segments are provided on the conductive film 1b so as to form a display pattern, thereby forming a display electrode.

2 beams 1 counter electrode substrate, this counter electrode substrate 2 also has a transparent 4-electrode film 2b of ITO on a glass treatment 2a, similar to the above-mentioned display electrode substrate 1.
Although not shown in FIGS. 2 and 3, a counter electrode material layer is provided on the transparent conductive film 2b, thereby forming a counter electrode. 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 provided on the transparent conductive film Ib of the lead terminal attaching portion of the display electrode substrate by electroplating as described above. The lead terminal 4 has a lower piece 4a of the holding portion 4a.
2 in contact with the nickel plating layer 5,
The clamping part 4a is fitted into the end of the display electrode substrate 1 and attached to the display electrode substrate 1, and a conductive paste is applied to the part where the lead terminal 4 is attached, and then an epoxy resin is applied on top of the conductive paste to form the lead terminal. 4 is fixed to the display electrode substrate l.

A plurality of lead terminals 4 on the display electrode side as described above are attached along both (j, l+ ends) of the display electrode substrate 1, as shown in FIGS. A desired number of lead terminals 4 are attached to the display electrode substrate l according to the number of segments constituting the display pattern and the number of display patterns. segment 7
The display pattern is composed of an aggregate of 8 to 7g, and in order to drive these segments 78 to 7g independently, the transparent conductive film 1b is appropriately cut by etching to form independent conductive paths 15a to 15g. is forming. The lead terminals 4 are attached to the display electrode substrate 1 in such a manner that electricity can be supplied to each transparent conductive film 1b constituting an independent conductive path.
G is designed to be able to develop color and l to produce white color independently. Note that 6 in Figures '154-5 is a lead terminal on the opposite pole side, and similarly to the lead terminal 4 on the display pole side, this lead terminal 6 on the opposite pole side has its clamping portion 6a connected to the display pole base Fj. , 1 is attached to the display electrode substrate l by fitting into the ends of the electrodes 1 and 1. However, this opposite electrode lead product 1
An insulating portion 1c (see FIG. 5) is provided on the transparent conductive film 1b by etching, and the lead terminal 6 on the opposite electrode side and the lead terminal 4 on the display electrode side adjacent thereto are connected to each other. are electrically isolated.

FIG. 6 is a cross-sectional view schematically showing the electrochromic display element portion of the electrochromic display element with lead terminals of the present invention. As described above, the display electrode substrate 1 has a transparent conductive film 1b of ITO on a transparent glass slope 1a. formed,
The display electrode 9 is formed by forming an electrochromic substance rf51 on the transparent conductive film lb of the display electrode substrate 1.

Although not shown, an undercoat of silicon dioxide (Si02) may be applied to the transparent glass plate 1a before forming the transparent conductive film 1b. A protective film 8 of silicon dioxide is formed on a portion of the transparent conductive film 1b where the electrochromic substance M7 is not formed. Note that the electrochromic substance I'57 is the fourth
5 and 7, the transparent conductive film tb is appropriately cut by etching, and each segment 78 of the electrochromic substance is formed into segments.
7g (see FIG. 7) are formed with independent conductive paths 15a to 15g, respectively, so that they can be driven independently. As the electrochromic substance, transition metal oxides such as tungsten oxide (WO3), iridium oxide (lr02), and molybdenum oxide (MoC2), Prussian blue, tetrathiafulvalene derivatives, viologen derivatives, etc. are usually used. Tungsten oxide is used.

The χ1 homopolar base treatment 2 is formed by forming a transparent conductive film 2b of ITO on a transparent glass 1 film 2a, and using iron tungstate (F 02 (WO4) 3 ) as a counter electrode material on the transparent conductive film 2b. By forming a counter electrode material layer 10 made of a conductive additive and a binder, the counter Jffil
l is formed. This counter electrode substrate 2 is the display electrode substrate 1.
Since such transparency is not required, the substrate may be made of a metal plate, or a ceramic plate or a plastic plate as long as a conductive portion corresponding to the transparent conductive film 2b is provided.

In addition, in the present invention, electrochromic substances,
Although the counter electrode material may be other than those exemplified above, it is necessary to select a combination of the electrochromic substance and the counter electrode material so that the display electrode side is on the negative electrode side.

Reference numeral 12 denotes a background material placed close between the electrochromic material layer 7 of the display electrode 9 and the counter electrode material layer 10 of the counter electrode 1). It is made of a porous polytetrafluoroethylene sheet, and 13 is a mixture of propylene carbonate and lithium perchlorate at 1.0 mol/j! It is a dissolved liquid electrolyte.

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 portion, and is an enlarged plan view of the display electrode viewed from the side on which the electrochromic material layer 7 is provided.

The display pattern R is provided with seven segments 1 to 7a to 7g forming a figure-eight display pattern.

Reference numerals 15a to 15g are conductive parts through which the electricity necessary for the segments 7a to 7g of the electrochromic substance to cause a coloring reaction are conducted. These conductive portions 15a to 1 are formed by cutting.
The resistance of 5g is adjusted to be inversely proportional to the area of each segment 7a-7g of electrochromic material.

Insulating parts 16a to 16h are provided to prevent short-circuiting of the conductive parts 158 to 15g, and are provided by partially removing the transparent conductive film 1b by etching. In addition, 16i and 163 are segment 7
This is an insulating barrier provided to prevent a difference in response speed between segments a and 7d due to rapid current flow. As mentioned above, the lead terminal mounting portion on the display electrode side of the display electrode substrate 1 is arranged in accordance with the number of segments of the electronic comic constituting the display pattern, that is, the number of conductive parts made of the transparent conductive film 1b. are provided in large numbers depending on the number of display patterns, and lead terminals 4 are attached to these portions.

FIG. 8 schematically shows the lead terminal mounting portion 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. In the figure, 14 is the display pole side. At this stage, the surface layer of the lead terminal mounting portion is composed of the transparent conductive film 1b, and corresponds to the end of the conductive portion shown in FIG.

As is clear from FIG. 8, the lead terminal mounting portions 14 on the display pole side are arranged in multiple stages according to the number of segments constituting the display pattern and the number of display patterns. The metal plating layer 5 is formed on the transparent conductive film lb of the terminal attaching portion 14 by electroplating as described above. 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.
This corresponds to the end of the insulating section in FIG. 8 above. In addition, 1
Reference numeral 8 denotes a lead terminal mounting portion on the opposing pole side.

Example 2 As in Example 1, using the amount of electricity injected into the electrochromic display element as a plating power source, 0.1 μm thick nickel plating was applied to the lead terminal mounting portion on the display electrode side of the display electrode substrate, and then chemical plating was applied. Nickel plated.

The chemical nickel plating bath contains nickel sulfate 20g/l, sodium hypophosphite 1Og/12, lactic acid 3g/β, and sodium citrate 5g/(!, sourium acetate 5g/
p I-1 is adjusted to 5.

The plating temperature was 50°C, and the plating time was 50 minutes, and a chemical nickel plating layer with a thickness of 3 μm was formed on the nickel plating layer formed by the electroplating.

After forming a nickel plating layer on the transparent conductive film of the lead terminal mounting portion on the display side of the display electrode substrate as described above, the lead terminals were attached and fixed to the display electrode substrate in the same manner as in Example 1. .

The electrochromic display element with lead terminals assembled as described above has a contact resistance between the lead terminals 4 and the display electrode substrate 1 of 0.2Ω, which is higher than that of the conventional electrochromic display element with lead terminals. It has low contact resistance, and when voltage is applied under the same conditions, it was able to produce clearer displays with higher color density than conventional products.

In addition, although the case of nickel plating was shown in the above-mentioned example, the same effect as the example can be exhibited even when using metal plating other than nickel.

〔Effect of the invention〕

As explained above, in the present invention, an independent conductive path is secured on the transparent conductive film of the lead terminal attachment part of the display electrode substrate, and the element contents such as electrochromic substances are not contaminated, and the present invention can be easily performed. We were able to efficiently form a metal plating layer using simple operations, thereby reducing the contact resistance between the lead terminals and the display electrode substrate, and achieving a clear display with high color density.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing a state in which metal plating is performed on a transparent conductive film of a lead terminal attaching portion on the display electrode side of a display electrode substrate of an electrochromic display element 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 4 is a schematic perspective view, FIG. 5 is a schematic plan view, and FIG. 6 is a cross-sectional view of the electrochromic display element; 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. ■...Display electrode substrate, 1b...Transparent conductive film, 4...
・Lead terminal on display pole side, 5...Metal plating layer, 9...Display pole, 1)...
・Counter electrode, 13...TL solution, 14...Lead terminal connection on display electrode side (1 part, 20...Electrochromic display element, 21...Plating bath No. 1, Sen No. 2 section No. 4 Figure 6

Claims (2)

[Claims] (1) In manufacturing an electrochromic display element with a lead terminal, which is formed by attaching a lead terminal to an electrochromic display element having a display electrode, a counter electrode, and an electrolyte, electricity is injected into the electrochromic display element, and the electrochromic display element is Manufacture of an electrochromic display element with lead terminals, characterized in that a metal plating layer is formed by electroplating on the transparent conductive film of the lead terminal attachment part on the display electrode side of the display electrode substrate using electricity injected into the display electrode as a plating power source. Method. (2) In manufacturing an electrochromic display element with a lead terminal, which is formed by attaching a lead terminal to an electrochromic display element having a display electrode, a counter electrode, and an electrolyte, electricity is injected into the electrochromic display element, and the electrochromic display element is Using the electricity injected as a plating power source, electroplating is performed on the transparent conductive film of the lead terminal attachment part on the display electrode side of the display electrode substrate, and then a metal plating layer is formed by chemical plating on the metal plating layer formed by the above electroplating. A method for manufacturing an electrochromic display element with lead terminals, characterized in that: