GB2052474A - Liquid Crystal Display Element - Google Patents
Liquid Crystal Display Element Download PDFInfo
- Publication number
- GB2052474A GB2052474A GB8011047A GB8011047A GB2052474A GB 2052474 A GB2052474 A GB 2052474A GB 8011047 A GB8011047 A GB 8011047A GB 8011047 A GB8011047 A GB 8011047A GB 2052474 A GB2052474 A GB 2052474A
- Authority
- GB
- United Kingdom
- Prior art keywords
- weight
- electroconductive
- liquid crystal
- crystal display
- paste
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1345—Conductors connecting electrodes to cell terminals
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C3/00—Glass compositions
- C03C3/04—Glass compositions containing silica
- C03C3/062—Glass compositions containing silica with less than 40% silica by weight
- C03C3/07—Glass compositions containing silica with less than 40% silica by weight containing lead
- C03C3/072—Glass compositions containing silica with less than 40% silica by weight containing lead containing boron
- C03C3/074—Glass compositions containing silica with less than 40% silica by weight containing lead containing boron containing zinc
- C03C3/0745—Glass compositions containing silica with less than 40% silica by weight containing lead containing boron containing zinc containing more than 50% lead oxide, by weight
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C4/00—Compositions for glass with special properties
- C03C4/14—Compositions for glass with special properties for electro-conductive glass
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
- H05K1/09—Use of materials for the conductive, e.g. metallic pattern
- H05K1/092—Dispersed materials, e.g. conductive pastes or inks
Landscapes
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- General Chemical & Material Sciences (AREA)
- Nonlinear Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Mathematical Physics (AREA)
- Crystallography & Structural Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Glass Compositions (AREA)
- Liquid Crystal (AREA)
Abstract
A liquid crystal display element comprises a liquid crystal material contained between two electrode substrates and an electroconductive means between the electrodes, said electroconductive means being made from an electroconductive paste comprising a low-melting point glass having the composition of 70 to 90% by weight of PbO, 5 to 15% by weight of B2O3, 10% by weight or less and more than 0% of ZnO, 0.1 to 3% by weight of CuO, 0.1 to 3% by weight of Bi2O3, 0.5 to 3% by weight of SiO2 and 0.5 to 3% by weight of Al2O3, and at least one electroconductive material selected from Ag, Au and Pd. The element gives reliable electroconductivity and very good chemical and mechanical stability.
Description
SPECIFICATION
Liquid Crystal Display Element
This invention relates to a liquid crystal display element, more particularly to one having an electro-conductive means of special composition between the electrode substrates.
Liquid crystal display elements generally used are formed by sealing the periphery of a pair of glass plates spaced at a constant distance, each inner surface of said glass plates being coated by display electrodes of transparent conductive film and orientation treatment film, and pouring a liquid crystal material into the resulting space. A diagrammatic sectional view of a typical example of such liquid crystal display elements is shown in
Figure 1.In Figure 1, 1 a and 1 b denote transparent glass substrates facing each other, 2 denotes a sealant which seals the periphery of the glass substrates 1 a and 1 b, 3a and 3b denote an upper-board electrode which serves as a display upper-board and an under-board electrode, respectively, consisting of transparent electroconductive film coated on the inner surfaces of the glass substrates 1 a and 1 b facing each other, 3c denotes a lead-out wire from the upper-board electrode 3a, 4a and 4b denote orientation controlling films formed on the surfaces of electrodes 3a and 3b facing each other, 5 denotes a conductive path electrically connecting the upper-board electrode 3a and the lead-out wire 3c placed on the under board, and 6 denotes an inner space in which a liquid crystal material is filled.In such a liquid crystal display element, a liquid crystal material which is orientated at a certain direction by the orientation controlling films 4a and 4b is disturbed by an electric field formed between the upper-board and under-board electrodes 3a and 3b to intercept the transmission of light, which results in displaying the desired pattern.
In usual liquid crystal display elements, the inner electrodes 3a and 3b as shown in Figure 1 are connected to the outer portion by lead-out wires. In order to collect leads on one substrate, it is necessary to use electroconductive paths which connect them with electrodes on the other substrate. In Figure 1, the conductive path 5 made from an electroconductive paste is used for such a purpose. This invention relates to the improvement in such an electroconductive paste.
The electroconductive paste is, in general, fusion bonded at the same time as the sealant 2 is fusion bonded by heating. Since higher fusion bonding temperature deteriorates properties of the transparent electroconductive films and the orientation controlling films in liquid crystal display elements, it is desirable to use an electroconductive paste having a fusion bonding temperature as low as possible. For example, in the case of using an organic film as the orientation controlling film, the fusion bonding temperature should be about 430"C or lower and the operation of sealing the periphery of the glass substrates is conducted at about 4300C or lower.
Thus, the electroconductive paste should be able to be fusion bonded at about 4300C or lower and be chemically sufficiently stable and be abie to give sufficient electroconductivity.
On the other hand, the conductive path made from the electroconductive paste should be chemically stable since it contacts with the liquid crystal material. When the conductive path is formed outside the peripheral sealing, it should be chemically sufficiently stable against outside water and moisture and also should be mechanically stable.
Therefore, electroconductive pastes which can be fusion bonded at about 430013 or lower and have chemical and mechanical stability as well as good electroconductivity have long been desired.
It is an object of this invention to provide such an electroconductive paste used for forming conductive paths which can be used in liquid crystal display elements.
This invention provides a liquid crystal display element comprising a liquid crystal material contained between two electrode substrates and an electroconductive means between the electrodes, characterized in that said electroconductive means is made from an electroconductive paste comprising a low-melting point glass comprising
70 to 90% by weight of PbO,
5 to 15% by weight of B203,
10% by weight or less of ZnO,
0.1 to 3% by weight of CuO,
0.1 to 3% by weight of By203, 0.5 to 3% by weight of SiO2, and
0.5 to 3% by weight of Al203, and at least one electroconductive material selected from the group consisting of Au, Ag and
Pd.
This invention also provides an electroconductive paste used for forming the electroconductive means such as conductive paths in a liquid crystal display element.
The electroconductive paste can be prepared by using a finely powdered low-melting point glass having the composition as mentioned above, at least one finely powdered eiectroconductive material of Ag, Au or Pd, a binder conventionally used such as nitrocellulose, ethylcellulose, methylcellulose, etc., and a conventional solvent such as a-terpineol, isoamyl acetate, carbitol acetate, butyl acetate, etc. It is also possible to use one or more proper surface active agents and dispersants together with them.
Reasons for using the low-melting point glass are to fusion bond and solidify the electroconductive material so as to increase chemical and mechanical strength thereof.
The weight ratio of the low-melting point glass to the electroconductive material can be determined depending on physical properties obtained. Figure 2 is a graph showing the relationship between specific resistance and the composition of the electroconductive paste. As shown in Figure 2, electroconductivity is remarkably lowered when the proportion of the low-melting point glass exceeds 70% by weight and the proportion of the electroconductive material is below 30% by weight (a total of the two being 100% by weight). Since the value of specific resistance is greatly changed by the particle size and shape (e.g. spherical, needle-like, etc.) of the electroconductive material, it is shown in Figure 2 as a belt having a certain width.Taking these points into consideration, the most preferable composition of the electroconductive paste which satisfies required properties of the liquid crystal display element is in the range of 70% by weight or less of the low-melting point glass and 30% by weight or more of the electroconductive material. On the other hand, when the proportion of the low-melting point glass is less than 30% by weight and the proportion of the electroconductive material exceeds 70% by weight, there is a tendency to lose airtightness, which results in allowing liquids and gases to penetrate into the inner portion due to insufficiency of glassy nature of the surface and to bring about chemical reactions, and mechanical strength which can be measured by, for example, hardness according to the scratching method, is also lowered, which results in lowering in reliability.Therefore, in order to maintain reliability of the liquid crystal display element, a preferable range of the composition of the electroconductive paste is 30% by weight or more and 70% by weight or less, more preferably 55 to 65% by weight, of the low-melting point glass and 70% by weight or less and 30% by weight or more, more preferably 45 to 35% by weight, of the electroconductive material, the total of the two being 100% by weight.
The low-melting point glass should have the composition of 70 to 90% by weight of PbO, 5 to 15% by weight of B203, 10% by weight or less and more than zero of ZnO, 0.1 to 3% by weight of CuO, 0.1 to 3% by weight of By203, 0.5 to 3% by weight of SiO2 and 0.5 to 3% by weight of
Al203. When PbO is less than 70% by weight, the melting point is raised, while when PbO is more than 90% by weight, the coefficient of thermal expansion (cur) is increased to lower the strength.
When B203 is less than 5% by weight, the coefficient of thermal expansion is increased and chemical strength is lowered, while more than 1 5% by weight, the melting point is raised. When
ZnO is zero, the coefficient of thermal expansion cannot be adjusted, while more than 10% by weight, the melting point is raised and there arises a tendency to cause devitrification. In order to lower the melting point and the coefficient of thermal expansion and to prevent the devitrification, CuO and Bi203 are added in the range of 0.1 to 3% by weight respectively. SiO2 and Al203 are added in the range of 0.5 to 3% by weight in order to increase chemical strength and to prevent the devitrification.More preferable glass composition is as follows:
PbO 7983% by weight, B203 913% by weight,
ZnO 2- 5% by weight,
CuO 1.52.5% by weight, By203 2.02.8% by weight, SiO2 1.02.5% by weight
Al203 1.02.5% by weight, Aslhe electroconductive material, at least one
powder of Ag, Au or Pd, is used, since these
materials have low specific resistance and
considerable chemical stability.
It is the most preferable to use the low-melting point glass having an average particle size of about 3 to 8 y and the electroconductive metallic material powder having an average particle size of about 0.8 to 5 y.
The electroconductive paste can be prepared, for example, by adding to a mixture of powders of the low-melting point glass and the electroconductive material mentioned above a binder, e.g. nitrocellulose, methylcellulose, or ethylcellulose, a solvent, e.g. a-terpineol, butyl acetate, isoamyl acetate or butylcarbitol acetate, and if necessary, one ore more surface active agents and dispersants, and kneading the resulting mixture sufficiently to give a paste. The resulting paste is coated on the prescribed area by means of a silk screen process, a dropping method by using a dispenser, or the like. The coated paste is calcined at the same time as the formation of peripheral sealing, for example, at about 41 00C for about 30 minutes.Needless to say, liquid crystal display elements containing the conductive path 5 by using the electroconductive paste of this invention can be prepared by employing a conventional method.
This invention is iilustrated by way of the following examples, in which all percents are by weight unless otherwise specified.
Example I
Low-melting point glass having a composition of 80% of PbO, 13% of 8203,3% of ZnO, 1% of CuO, 1% of Bi203, 1% of BiO2 and 1%ofAl2O3and an average particle size of about 6 ,u in the proportion of 60% and Au powder having a spherical shape with an average particle size of about 3 M in the proportion of 40% were sufficiently mixed in a mortar. To the resulting mixture, 0.3% of nitrocellulose and 1 5% of nbutyl-carbitol acetate based on the weight of the mixture were added and kneaded to give a paste.
The paste was coated in dots on the inner surface of one of electrode substrates of a liquid crystal display element. The thus treated electrode substrate was joined to another electrode substrate by using a sealant as shown in Figure 1 and calcined at about 41 00C for about 30 minutes to form a conductive path electrically connecting the electrodes on the both substrates.
Electroconductivity between the upper-board and under-board electrodes was very good at the initial time and even after repeating 200 times of cooling-and-heating-under-moisture cycles (cooling at --250C and heating at 700C under a relative humidity of 90%, 1 cycle being 6 hours) while keeping very good chemical and mechanical stability.
Example 2
An electroconductive paste was prepared by using the same glass as used in Example 1, Ag powder having an average particle size of about 0.8 Fl in the same proportions as used in Example 1, 0.3% of nitro-cellulose and 20% of nbutylcarbitol acetate in the same manner as described in Example 1. The resulting paste was applied to a liquid crystal display element in the same manner as described in Example 1.
Electroconductivity was tested in the same manner as described in Example 1 with a very good result of reliable electroconductivity together with very good chemical and mechanical stability.
When an electroconductive paste was prepared in the same manner as described above except for changing the mixing ratio of the glass to the Ag powder to 10% to 90% and applied to a liquid crystal display element and tested as mentioned above, the conductive path was pealed off from the electrode substrate after 5 cycles of cooling-and-heating-under-moisture resulting in defective electroconductivity.
As mentioned above, according to this invention, the electroconductive paste can be fusion bonded at about 430 C or lower to give a conductive path having reliable electroconductivity and chemical and mechanical stability. Thus reliability of liquid crystal display elements can be improved remarkably. Further, since the paste can be calcined at about 4300C or lower, change of properties of individual films or portions in the element can be prevented, which results in improving various properties of the liquid crystal display element greatly.
Claims (7)
1. A liquid crystal display element comprising a liquid crystal material contained between two electrode substrates and an electroconductive means between the electrodes, said electroconductive means comprising an electroconductive paste comprising a low-melting point glass comprising
70 to 90% by weight of PbO,
5 to 15%byweightofB203, 10% by weight or less and more than 0% of
ZnO,
0.1 to 3% by weight of CuO,
0.1 to 3% by weight of Bi2O3,
0.5 to 3% by weight of SiO2, and
0.5 to 3% by weight of Al203, and at least one electroconductive material selected from the group Ag, Au and Pd.
2. A liquid crystal display element according to claim 1 wherein the slectroconductive paste comprises 30 to 70% by weight of the lowmelting point glass and 70 to 30% by weight of the electroconductive material, the total of the two being 100% by weight.
3. A liquid crystal display element according to claim 1 or 2 wherein the low-melting point glass has an average particle size of 3 to 8 M and the electroconductive material has an average particle size of 0.8 to 5 y.
4. An element according to claim 1 substantially as hereinbefore described with reference to either of the Examples.
5. An electroconductive paste for forming an electroconductive means in a liquid crystal display element which comprises
(a) 30 to 70% by weight of a powdered low
melting point glass comprising:
70 to 90% by weight of PbO,
5 to 15% by weight of B203,
10% by weight or less and more than 0% of
ZnO,
0.1 to 3% by weight of CuO,
0.1 to 3% by weight of Bi203,
0.5 to 3% by weight of SiO2, and
0.5 to 3% by weight of Awl203, (b) 70 to 30% by weight of at least one
powdered electroconductive material
selected from Ag, Au and Pd, a total of the
glass and the electroconductive material
being 100% by weight,
(c) a binder and
(d) a solvent.
6. A paste according to claim 5 wherein the low melting point glass has an average particle size of 3 to 8 y and the electroconductive material has an average particle size of 0.8 to 5 y.
7. A paste according to claim 5 substantially as hereinbefore described with reference to either of the Examples.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5913279A JPS55151621A (en) | 1979-05-16 | 1979-05-16 | Liquid crystal display element |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2052474A true GB2052474A (en) | 1981-01-28 |
Family
ID=13104472
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8011047A Withdrawn GB2052474A (en) | 1979-05-16 | 1980-04-02 | Liquid Crystal Display Element |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS55151621A (en) |
| CH (1) | CH645994A5 (en) |
| GB (1) | GB2052474A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3905276C1 (en) * | 1989-02-21 | 1990-05-03 | Demetron Gesellschaft Fuer Elektronik-Werkstoffe Mbh, 6450 Hanau, De | |
| EP1793624A3 (en) * | 2005-11-30 | 2008-04-23 | Samsung SDI Co., Ltd. | Electronic display device |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60133430A (en) * | 1983-12-22 | 1985-07-16 | Alps Electric Co Ltd | Connecting method of terminal of liquid crystal display element |
| DE3635186A1 (en) * | 1986-10-16 | 1988-04-21 | Standard Elektrik Lorenz Ag | GRAPHITE-BASED SUSPENSION FOR PIPES |
| CN110217998B (en) * | 2019-07-11 | 2021-09-07 | 哈尔滨工业大学（深圳） | Lead-free conductive silver paste capable of being sintered at low temperature and preparation method and application thereof |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3873330A (en) * | 1973-11-19 | 1975-03-25 | Ibm | Bi{hd 2{b O{HD 3 {B and Al{hd 2{b O{HD 3{B containing PbO-ZnO-B{HD 2{B O{HD 3 {B low temperature sealing glass |
| JPS5157189A (en) * | 1974-11-14 | 1976-05-19 | Seikosha Kk | DENKIKOGAKUTEKIHYOJISOCHI OYOBI SONOSEIHO |
-
1979
- 1979-05-16 JP JP5913279A patent/JPS55151621A/en active Pending
-
1980
- 1980-03-31 CH CH253780A patent/CH645994A5/en not_active IP Right Cessation
- 1980-04-02 GB GB8011047A patent/GB2052474A/en not_active Withdrawn
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3905276C1 (en) * | 1989-02-21 | 1990-05-03 | Demetron Gesellschaft Fuer Elektronik-Werkstoffe Mbh, 6450 Hanau, De | |
| EP1793624A3 (en) * | 2005-11-30 | 2008-04-23 | Samsung SDI Co., Ltd. | Electronic display device |
| US7511774B2 (en) | 2005-11-30 | 2009-03-31 | Samsung Mobile Display Co., Ltd. | Three-dimensional display device |
| CN1976483B (en) * | 2005-11-30 | 2010-11-10 | 三星移动显示器株式会社 | Three-dimensional display device |
Also Published As
| Publication number | Publication date |
|---|---|
| CH645994A5 (en) | 1984-10-31 |
| JPS55151621A (en) | 1980-11-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |