JPS6028624A - Manufacture of display element - Google Patents

Abstract

PURPOSE:To manufacture an element high in contrast and long in life by laminating an electrosensitive layer on a conductive base plate and a transparent conductive layer on this layer by coating and vacuum evaporation. CONSTITUTION:An ITO transparent conductive layer 5 is formed on a glass plate 4 in 100 nm thickness by vacuum evaporation. The layer 5 is coated with an electrochromic dye, an electrolyte, and a polyacrylonitrile, then heated, and dried in vacuum to form a 2.6-7.0mum thick transparent electrosensitive layer 2. A transparent conductive material is deposited to this layer 2 in a vacuum vapor deposition device, and subjected to etching to obtain a 100 nm thick transparent conductive layer 3 in a prescribed pattern. This layer 3 has a sheet resistance of 100OMEGA/cm<2>, and a light transmittance of 85%.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Industrial Application Field The present invention relates to a method for manufacturing a display element 1, such as a liquid crystal display element or an enctrochromic element.

2. Prior Art Display elements known so far include liquid crystal display elements and electroluminescent elements.
A cell is constructed by sealing liquid crystal or liquid crystal material between two electrode plates. but,
The device itself becomes thicker and heavier, and it is difficult to increase the area of the cell. In addition, since the substance to be encapsulated is in a liquid state, the encapsulation process is troublesome and it tends to change over time.

Therefore, as a solid-state display element, primary (a) to Tb)
A method using an electro-pimic material as shown in the following has been proposed.

(Kl, laminated film of inorganic material tungsten oxide thin film and dielectric thin film (e.g. 5IO), tungsten oxide thin film and solid electrolyte (e.g. superionic conductive solid electrolyte such as lithium, PbAg4I
*, etc.), a laminated film of an oxidized iridium thin film and a dielectric thin film (above), etc.

(BL, polymer material organic dye (eg, viologen system, shifter cyanine complex) and electrolyte are dispersed in a polymer, and a polymer electrolyte resin layer is formed by bonding tetrathiafulvalene to polystine.

Tetrathiafulvalene or pyrazoline dyes pendantly bonded to polymers, etc.

On the other hand, polymer liquid crystal materials of the first order (cl to (dl) have also been proposed for use in solid-state display devices.

(C) Polymer γ-butyl L-glutamate (PBul, G) obtained from polypeptide and vinyl monomer + triethening CJ cold dimethacrymate (TGDM
), PBuLB + etching glycol dimethacrylate (EGDM), poly(r-p-p-pvir L-glutame)) (PPrLG) + cyclohexyl methacrylate (CHMA), etc.

(d), human P-? Polymer Obtained from Sibu P Pill Cell P-S (RPC) and Vinyl Monomer The present inventor has investigated various materials for solid-state display elements as described above, and found that all of these materials are suitable for display. It has been found that when applied as an electrically sensitive layer of a device, there is a problem in that the continuous heat resistance is as low as 150° C. or less, which limits the electrode material that can be formed on the electrically sensitive layer.

- As an example, a device is known in which a gold electrode is formed on a thin film (electrically sensitive layer) of a polymer electrolytic material. Temperature that does not cause changes in material and physical properties (150'
It can be formed by IC such as vacuum evaporation (below c). However, in devices with such gold electrodes, the light transmittance of the gold electrode itself is relatively low.
The contrast becomes very poor when displaying light through the element.

Not suitable for display purposes. Moreover, a boundary reaction occurs between the metal electrode and the polymer layer, leading to deterioration of the polymer, resulting in display errors.

In this way, considering the continuous heat resistance temperature of the polymer thin film, [the upper electrode that can be formed can only be formed by vapor deposition of a metal material such as gold, but even if it is formed in this way, the above-mentioned drawbacks can be avoided. I can't.

3. Purpose of the invention The object of the invention is particularly in solid-state display elements.

It is an object of the present invention to provide a method for manufacturing an element with high contrast and long life.

4. Structure of the invention and its effects: 1. The present invention is directed to manufacturing a display element characterized in that at least an electrically sensitive layer and a transparent conductive layer are laminated on a conductive substrate.

The present invention relates to a method of manufacturing a light emitting device, characterized in that the transparent conductive layer is formed by reactive vapor deposition.

According to the present invention, since the above-mentioned transparent conductive layer is formed by reactive vapor deposition, the temperature of the substrate at the time of formation is maintained below the continuous heat resistance temperature of the above-mentioned electrically sensitive layer (particularly below 150°C), and the transparent conductive layer is manufactured. membrane becomes possible. Therefore, a transparent conductive layer can be formed without adversely affecting the polymer electrosensitive layer (deterioration of physical properties or dielectric breakdown). Moreover, since a transparent conductive layer is provided on the electrically sensitive layer, the display contrast during light transmission display is extremely good, and there is no deterioration of the electrically sensitive layer as seen with metal electrodes, resulting in a longer service life. becomes possible.

In addition, the "continuous heat-resistant temperature (or maximum service temperature)" described in this specification is defined as "the maximum temperature when no change in material or physical properties occurs under long-term service requirements"['PolymerMaterials' (Ohmsha, 1st edition published March 20, 1960, 3
4-35)].

5. Examples Hereinafter, the present invention will be explained in detail by referring to examples.

First, with reference to FIG. 1, the basic structure of a solid-state light emitting device produced by the method according to this embodiment will be explained.

This light emitting device is composed of a conductive substrate 1, a polymer electrosensitive layer 2 disposed on the substrate, and a transparent conductive layer 3 disposed on this layer.

The conductive substrate l is made of, for example, a transparent glass plate 4 and ITO (In
dlum Tin Oxlde) transparent conductive layer 5. The conductive substrate 1 is not limited to the one shown in the figure, and the entire substrate may be made of a conductive material.Also, instead of the glass plate 4, a transparent polymer 1 such as a polyethylene tent sheet or a polyethylene sheet can be used. Films made of polyhedron, polyetherimide, polyetherketone, polyethersarpone can also be used.

The polymeric electrosensitive layer 2 is particularly made of a polymeric electromagnetic material or a polymeric liquid crystal material having a continuous heat resistance temperature of 150° C. or lower. Examples of polymeric electrochromic materials that can be used include various electrochromic dyes as described above, such as tetrathiafulvanic dyes and pyrazoline dyes.

These materials are actually dispersed in polymeric compounds, but as usable polymeric compounds.

Polystyrene resin (e.g. continuous heat resistance temperature 60-80℃
styrene type), polyvinyl alcohol resin (e.g., vinyl type with a continuous heat resistance temperature of 60 to 90°C), polymethacrylonitrile resin (e.g., a continuous heat resistance temperature of 60 to 90°C)
acrylic type with the same temperature of 80~150℃, polycarbonate type with the same temperature of about 120℃, same temperature of 60~150℃
100° C. Celltooth series), etc. Each of these polymer materials.

Demonstrates the transparency of polymers, and there are many types that can be used.
It has the advantage of being easy to process.

In addition to the various materials mentioned above, usable polymeric liquid crystal materials include PPrLG+ethyl acriline) (E
tA), PBuLG+C)IMA, PPrLG+
Methyl methacrylate (MMA), PPrl, G
f EDGM stop is mentioned.

Moreover, the transparent conductive layer 3 is made of ITO (IntOs and SnO
.

1c, transparent conductive layer 3 side. It is possible to make the contrast of the display pattern (that is, the color pattern due to the difference in absorption wavelength of the polymer layer 2 directly under the conductive layer 3 and the other region) sufficiently clear. Moreover, as will be described later, the transparent conductive layer 3 has a substrate temperature of 15
It is possible to form a film on the polymer layer 2 whose continuous heat resistance temperature is 150° C. or less when the temperature is 0'C or less, so that the polymer layer 2 does not suffer from deterioration of its physical properties.

Note 2: The device shown in FIG. 1 is an all-solid-state type.

It is thin and lightweight, and can be made into a large area. The entire surface of this element on the transparent conductive layer 3 side is preferably coated with silicon oxide, polymethyl methacrylate, etc. for surface protection.

Next, an example of a method for manufacturing a display element according to this embodiment will be described.

First, an ITO transparent conductive layer 5 (sheet resistance 100Ω/
c11-light transmittance 85 cm) is formed to a thickness of too X.

Next, a dispersion mixture having the following composition is prepared.

Composition Molar ratio Enctoμ chromic color $ 1 (Tetrathiafulvalene) Electrolyte K Polymer compound % (Polymethacrylonitrile) This mixture is coated on the transparent conductive layer 5, heated and dried under vacuum, and then thickened. A pale yellow transparent electrosensitive layer 2 with a thickness of 2.6 to 7.0 μm is formed.

Next, using the vacuum deposition apparatus shown in FIGS. 2 and 3, a transparent conductive material is deposited on the electrically sensitive layer 2, and this is processed by etching to form a transparent conductive layer 3 in a predetermined pattern. This transparent conductive layer 3 may be formed to have a thickness of 100X, and a sheet resistance of 100Ω/at/1. The light transmittance is 85cm.

The process for forming this transparent conductive layer will be described in detail.

That is, the Pelger 30 forming the vacuum chamber in FIG.
A vacuum pump (not shown) is connected to the Pel jar 3o through an exhaust path 38 having an inside of the butterfly valve 32, whereby the inside of the Pel jar 3o is preliminarily heated to a pressure of, for example, 10-5 to 10-7 Torr.
Keep it in a high vacuum state. A substrate 4 is placed inside the Pelger 30 and heated to a temperature of 15 by the heater 34.
The high frequency gas discharge device 3 is heated to 0° C. or lower, for example 60° C., and is connected to the gas inlet 36 (see FIG. 3).
7 (described in detail later) while introducing the activated and/or ionized reaction gas (0 W) into the Pelger 30 (gas pressure is I
' Torr, e.g. 6 X 10-' Torr)
Then, the deposition material is heated and evaporated from the evaporation source 25 disposed in the pell jar 30 so as to face the substrate 4.

This heating means is an electron beam 2 produced by an electron gun heating device 26.
7 (when the vapor deposition material is ITO) or a resistance heating method (when the vapor deposition material is In+Sn, or In and Sn alone) may be used. Further, a negative bias voltage 35 (-1 kV or less and -6 to -500 V or less) can be applied to the substrate 2 (actually, its back electrode (not shown)) as necessary. This bias voltage may be direct current or alternating current. Also includes ground potential.

Here, the gas discharge device 37 may be constructed as clearly shown in FIG. That is, for installation, a through hole (inlet) 40 connected to the gas inlet 36 is formed in the center of the plate 39, and a ring-shaped protrusion 41 with a small diameter and a ring-shaped protrusion with a large diameter are formed around the inlet 40. A protrusion 42 is provided concentrically. Then, a busy gas introduction pipe 43 is removably fitted and fixed to the inner protrusion 41 so as to wrap it around the inner protrusion 41.
Further, a cylindrical adhesion prevention member 44 is similarly fitted and fixed to the outer protrusion 42. For example, a coil-shaped discharge electrode 45 is wound between the outer periphery of the introduction pipe 43 and the inner periphery of the adhesion prevention member 44 . Introduction pipe 43 and adhesion prevention member 44
A common ring plate 46 constituting a part of the adhesion prevention member is fixed to the inner end surface of the introduction pipe 4 with screws 47.
3 and the adhesion prevention member 44 are attached to the method plate 39 in a state where the discharge electrode 45 is accommodated. However, various methods or orders can be considered for this attachment, and the ring plate 46 may be fixed in advance as described above and then fitted into the protrusions 41 and 42 at the same time.

For installation, a high frequency introduction terminal 48 connected to one end of an electrode 45 is fitted and fixed in the front part of the plate 39, and a gas introduction terminal 50 from the outside is connected to the center part through a threaded part 49.
is screwed into place. Additionally, water cooling pipes 71 and 72 are provided around the mounting plate 39 and the adhesion prevention member 44 to pass the cooling water 7o to prevent them from being heated. Furthermore, it is possible to introduce cooling water into the interior of the electrode 45 as well. The water cooling tubes 71, 72 may be separate pieces or may be integrated with each other at appropriate points. And the installation is on board 3
9 is removably fixed to a mounting base 53 inside the Pelger 3° by screwing a screw 52 into a peripheral screw hole 51. Here, the installation is performed on an installation stand 5 on which the above-mentioned high frequency gas discharge device 37 is removably fixed via a plate 39.
3 is fixed to the bottom wall 30a of the Pel jar 30 so that its position can be adjusted, thereby allowing the discharge device 37 to be appropriately installed at any position within the Pel jar 30. For this purpose, for example, an appropriate number of screw holes 73 may be formed at appropriate positions in the Pelger bottom wall 30a, and screws 74 may be screwed into the screw holes 73 to fix the installation base 53 to the Pelger wall. Therefore,
The arrangement of the discharge device 37 can be arbitrarily adjusted by adjusting the fixing position of the installation base 53 using the screws 74.

For example, it can be shifted in the direction 75 shown by the imaginary line.

Correspondingly, each pipe 50, 71, 72, etc. may be slackened by a predetermined length in advance and configured as a flexible pipe.

The above-mentioned discharge device 37 is configured as an L-coupling type (coupling type) using a coil electrode 45, and a high-frequency voltage (
For example, by applying a power of 13.56 MH, 300 W), ions or activation components of the reaction gas generated in the gas introduction tube 43 are released from the discharge port 56 into the space of the Pelger 30 (
That is, according to the above-described vacuum evaporation method (reactive evaporation method) in which the evaporated substance 25 is led out toward the substrate 4 into the flight space, the substrate 4 is held at a relatively low temperature,
The transparent conductive layer 3 made of ITO or the like can be formed in this way, and the film can be formed without damaging the underlying electrically sensitive layer 2. To solve this problem, it is possible to form a transparent conductive layer by sputtering instead of the above-mentioned reactive vapor deposition method, but in this case, there are the following problems. Namely, when the film is deposited by sputtering, ionization occurs. Bombardment damage from particles enters the electrically sensitive layer 2, and this layer itself is easily heated to exceed the continuous heat resistance temperature, and electrons and ions are accumulated on the electrically sensitive layer 2 (busy substrate - target When the potential difference between the two layers is large, the formation of an electric field may cause dielectric breakdown in the layer 2. What is the phenomenon in which electric sensor #2 is heated to a temperature higher than its continuous heat resistance temperature (for example, 200°C)?

Buttons may also be produced when a conventional vapor deposition method other than the above-mentioned reactive vapor deposition method is used.

In the above method, the temperature of the substrate 4 (Ts
) is 150°C or less, or the applied voltage (Vs) of the substrate 4
It is desirable that the voltage is −1 kV or less, or that both Tg≦150° C. and v8≦5 are the conditions. That is, as is clear from the experimental data in Figure 4, T8 is 1.
If the temperature exceeds 50℃, even the relatively heat-resistant nylon-based electrically sensitive layer tends to be thermally deformed, so T8≦150
℃, it is possible to maintain the properties of all available electrosensitive materials.

Furthermore, as shown in Figure 5, if Vs is not lowered to -1kV or less, the accumulation of charges (ions) on the substrate will increase significantly, causing significant local dielectric breakdown of the electrically sensitive layer. Short-circuit current inside the device tends to increase significantly.

The display element obtained by the above method has a driving voltage of 1, for example, 3~
Red color display can be performed at 4V.

The color disappears when the polarity of the applied voltage is changed. Further, the change in light transmission of the same element at a wavelength of 550 mμ during semi-coloring and decoloring is about 40 inches, which is good.

FIG. 6 shows a display element with a layered structure suitable for practical use.

In the device shown in FIG. 1, insulating layers 7 and 8 are provided between the electrically sensitive layer 2 and the upper and lower conductive layers 3 and 5, respectively. The insulating layer 7.8 consists of an oxide or nitride [often 5, for example SIO with a thickness of 500 to 1500 x
.

It can be formed from a membrane. These StO, membranes 7.
8 is O by the reactive vapor deposition apparatus shown in FIG.

S10, S while activating or ionizing the gas and introducing it.
By heating and evaporating tO or St.

The film can be formed in the same manner as described above.

Also, a film of 518N4-4% can be formed as a nitride. 6th
The element in the figure is %810. Due to the presence of the films 7 and 8, a longer life is possible, and good display can be achieved even after being turned on and off, for example, 107 times or more.
Note that it is also effective to provide only one of the above-mentioned sio and films 7 and 8.

In the display element shown in FIG.
Polymer: Dielectric breakdown voltage 10-30kV/am
, continuous heat resistance temperature of 66 to 80°C) may be used. In this case, this polymer solution may be applied to a thickness of 10 to 5 μm and dried.

FIG. 7 shows a liquid crystal display element suitable for practical use, which has an electrically sensitive layer 2 made of polymeric liquid crystal similar to that described above, and has the same layer structure as FIG. 6 in other respects. With this element, color tone changes can be observed at a driving voltage of 5V.

Various colors can be produced depending on the applied voltage, type of liquid crystal, temperature, etc. Further, the light transmission half change is about 40 inches.

The embodiment described above can be further modified based on the technical idea of the present invention.

For example, the layer structure and constituent materials of one display element are not limited to those described above, and may be changed in various ways.

For example, a laminate of a polymer EC (electrodynamics) and a polymer LC (liquid crystal) can also be created.
The film forming method for each layer may also be changed.

In addition, it is desirable to observe the display pattern of the display element from the conductive layer 3 side as in the above example (in this case, the conductive layer 5 and the substrate 4 do not need to be transparent), but if necessary, It can also be observed from four sides.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG. 1 is a schematic cross-sectional view of a display element. FIG. 2 is a schematic cross-sectional view of the reactive vapor deposition apparatus. FIG. 3 is a partially enlarged sectional view of FIG. 2 showing a high-frequency discharge device, and FIG. 4 is a diagram showing changes in physical properties of the electrically sensitive layer depending on substrate temperature. FIG. 5 is a diagram showing the change in short circuit current of the electrically sensitive layer depending on the substrate voltage. FIGS. 6 and 7 are schematic sectional views of the other two sides of the display element. In addition, in the reference numerals shown in the drawings. l...... Conductive substrate 2... Electrically sensitive layer 3... Transparent conductive layer 4... ...Glass plate (substrate) 5...
...Transparent conductive layer 7.8...Insulating layer 25...Vapour-deposited substance 37...High frequency gas discharge device 50...
...Reactant gas introduction pipe. Agent: Patent attorney Hiroshi Aisaka (and 1 other person) No. 10. 1 Figure 2 @30 1A ・True. No. 40 @,! ;mouth 0-gρρF-g KV Yasu store 6th

Claims (1)

[Claims] l. When manufacturing a display element in which at least an electrically sensitive layer and a transparent conductive layer are laminated on a conductive substrate, the transparent conductive layer is formed by warped vapor deposition. A method for manufacturing a display element. 2. The first claim in which the electrically sensitive layer has a continuous heat resistance temperature or a maximum operating temperature of 150°C or less
The method described in section. 3. The electrically sensitive layer is formed from a polymeric liquid crystal material. A method according to claim 2. 4. The electrically sensitive layer is formed from a polymeric material. A method according to claim 2. 5. A transparent conductive layer is formed from indium oxide and/or tin oxide. A method according to any one of claims 1 to 4. 6. As described in any one of claims 1 to 5, characterized in that a layer made of oxide or nitride is provided on at least one of the electrically sensitive layer and the conductive layers on both sides thereof. Method.