JPH03241320A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To make improvement in yield and the reliability of products by providing side line electrodes and bypassing the electrodes, thereby maintaining the conduction between the electrodes and leading-out terminals even when a discontinuity arises in the electrodes. CONSTITUTION:A coating layer 2 deposited on a substrate 1 is provided with internal via holes 2a and external via holes 2b of, for example, 0.25 mmphi by etching so as to expose respectively the internal junctures 4a positioned on the inner side of seals 5 and external junctures 4b positioned on the outer side of the seals 5 at the ends of the side line electrodes 4. The internal and external junctures 4a, 4b of the side line electrodes 4 are conducted respectively through the internal and external via holes 2a, 2b when an ITO film is deposited over the entire surface of the coating layer 2 and is etched to stripe shapes to constitute the electrodes 3. The conduction is maintained through the internal via hole 2a the internal juncture 4a the side line electrode 4 the external juncture 4b the external via hole 2b the leading-out terminal 3a in this way even if the electrodes 3 are disconnected by the external force of the seal 5 as the seal 5 crosses the central part of the side line electrodes 4.

Description

[Detailed Description of the Invention] [Summary] Regarding a liquid crystal display element, the purpose is to maintain conduction of the electrode even if the electrode is disconnected due to an external force of the seal, and to connect the substrate, the covering layer, the electrode, and the side path. It has an electrode and a seal, and the substrate is made of a transparent glass plate,
A color filter layer consisting of a transparent thin film colored in each of the three primary colors is deposited in a scattered manner,
The coating layer is a transparent insulating thin film that smoothes unevenness of the color filter layer, the coating layer is coated on the entire surface of the substrate, and the electrode is a transparent conductive thin film. The bypass electrode is a conductive thin film that is attached to the coating layer, and is provided in a striped manner passing over the color filter layer through the coating layer, and the bypass electrode is a conductive thin film, and the electrode is attached to the coating layer. The seal is a thermosetting adhesive that seals the liquid crystal from above the coating layer to the peripheral edges of the two opposing substrates. The bypass electrode has an inner connection part at the inner end of the seal and an outer connection part at the outer end of the seal, and the covering layer has an inner connection part at the inner end of the seal.・It has inner and outer via holes corresponding to each of the outer connection parts,
The electrode is configured such that the inner and outer via holes are electrically connected to the inner and outer connecting portions, respectively, and the electrode has a lead-out terminal at the outer end of the seal.

[Industrial application field]

The present invention relates to a liquid crystal display element, and more particularly to a liquid crystal display element having a color filter, which is configured so that conductivity of the electrodes can be maintained even if the electrodes are disconnected due to an external force of a seal.

In recent years, rapid progress in electronics has promoted the miniaturization of electronic devices, but displays, which are one of the elemental devices of the interface between machines and humans,
CRT displays are still widely used.

However, recently the so-called LCD (
L 1quid Crystal D 1spray
, liquid crystal displays) are attracting attention as a new display that can replace CRT displays, which are large, heavy, and not particularly suitable for portability.

In the past, LCDs were considered to be very impractical as large flat displays due to their slow operating speed, low contrast, difficulty in producing color, and complex drive circuits. However, recent innovative developments such as the development of new liquid crystal materials and driving methods, and improvements in display element manufacturing technology have created the possibility of a display that is as good as a CRT display.

However, in order to achieve uniform display quality on a large screen, there is still room for consideration in terms of manufacturing technology, and development is progressing in various places.

[Conventional technology]

Liquid crystal display elements move large molecules in a viscous liquid and use optical effects such as polarization to obtain a display. Generally, the response is slow, so liquid crystal display elements are used. LCDs were said to be unsuitable for displaying fast-moving images such as moving images.

However, T N (Twist Nematic) and S T N (S super
While a new liquid crystal material called T N (Super TN) is being developed, T P T (Thin Film
The so-called active matrix method, in which transistors are arranged for each pixel, has been realized through the development of drive ICs, and color filter manufacturing technology has also progressed, leading to the emergence of portable and wall-mounted color TVs. .

FIG. 5 is a cross-sectional view of the structure of an example of a conventional color liquid crystal display element, and FIG. 6 is an enlarged cross-sectional view of the main part of FIG.

In the figure, 1 is a substrate, 1a is a color filter layer, 2 is a coating layer, 3 is an electrode, 5 is a seal, 6 is a liquid crystal, and 9 is a liquid crystal display element.

The substrate 1 is a transparent and smooth glass plate, and toad-shaped color filter layers 1a of three colors, cyan, yellow, and magenta, are alternately arranged and adhered thereon. A shielding film 1b made of, for example, chromium is provided in the gap between the color filter layers 1a to prevent light from leaking.

Since the electrode 3 must be transparent, it is generally made of ITO.
(Indium Tin Oxide) film is often used. However, since the ITO film has a thickness of several nanometers, it is difficult to provide it directly on the surface of the substrate 1, which is provided with the color filter layer 1a and is highly uneven.

Therefore, a coating layer 2 made of polyimide, for example, is provided to fill in the unevenness of the color filter layer 1a and make the surface smooth.

An ITO film is provided on the coating layer 2, and the ITO film is etched in stripes in the X direction or the Y direction to form the electrodes 3. In this way, when the two substrates 1 are stacked facing each other, the intersection of the electrodes 2 is the color filter layer 1a.
This forms a so-called matrix electrode, which becomes a pixel of, for example, 640×400 dots.

Further, the end portion of the electrode 3 provided around the substrate 1 has a narrower pattern width than the electrode 3, and serves as a lead-out terminal 3a connected to a drive circuit (not shown) or the like.

The substrate 1 thus produced is sealed around two substrates l facing each other with a gap of about 7 μm, for example, with a thermosetting seal 5 made of, for example, epoxy resin. For example, liquid crystal 6 is injected into the gap under vacuum and sealed liquid-tightly.

When the liquid crystal display element 9 is of the TN type, a nematic liquid crystal material with molecular alignment is used, and an alignment film of polyimide or polyvinyl alcohol with a thickness of several tens of nanometers is formed on the electrode 3. Sometimes it is provided.

By the way, the lead terminal 3a of the electrode 3 is exposed at the end of the substrate 1 outside the seal 5 in order to be connected to an external drive circuit (not shown). The electrode 3 must therefore pass under the sealing part, ie the seal 5.

However, external forces such as tension, compression, and displacement between the two substrates 1 are applied to the seal 5 not only during the manufacturing process of the liquid crystal display element 9 but also when it is incorporated into a device or used as a product. . Therefore, when sealing is performed with the seal 5 through a three-layer film structure in which the covering layer 2 and the electrode 3 are provided on the substrate 1, the covering layer 2 is not a rigid film, but is in close contact with the substrate l. Since the strength is not strong, the coating layer 2 may peel off from the substrate 1 due to the inability to withstand external forces, or the electrode 3 may become distorted and break.

Therefore, as shown in FIG. 6, a conventional liquid crystal display element 9
In this case, the covering layer 2 is removed by etching or the like inside the seal 5, so that the electrode 3 is directly deposited on the substrate l at the position where the seal 5 is provided. In this case, the adhesion strength between the substrate 1 and the electrode 3 is strong, so that the seal 5 can also be strong.

However, since the covering layer 2 is provided with a thickness of 2 μm or 3 μm for the purpose of flattening the unevenness of the color filter layer 1a, there are no steps at the etched end of the covering layer 2.
c occurs. Therefore, the electrode 3 sometimes breaks at this step 2c.

[Problem to be solved by the invention]

As mentioned above, the adhesion of the coating layer to the substrate is not necessarily good, so in the past, the part that would be sealed by the seal was removed by etching, etc., the electrode was directly attached to the substrate, and then the seal was placed on top of it. was provided to compensate for poor adhesion.

However, when the coating layer is removed, a step is created which is an order of magnitude larger than the thickness of the electrode, and this step causes the problem of disconnection of the electrode.

Therefore, in the present invention, the bypass electrode provided on the substrate and the electrode provided on the coating layer are branch-connected through via holes, and even if the electrode is disconnected due to external force of the seal, the conduction of the electrode is maintained. It is an object of the present invention to provide a liquid crystal display element that is configured such that it can be maintained.

[Means to solve the problem]

The problem described above includes a substrate, a covering layer, an electrode, a bypass electrode, and a seal, and the substrate is made of a transparent glass plate, and is colored in each of the three primary colors. A color filter layer made of a transparent thin film is deposited in a scattered manner, and the covering layer is a transparent insulating thin film that smoothes the unevenness of the color filter layer. , which is applied to the entire surface of the substrate, and the electrode is a transparent conductive thin film which is applied to the coating layer, and a stripe which passes over the color filter layer through the coating layer. The bypass electrode is a conductive thin film that is adhered to the substrate facing the electrode via a coating layer, and the seal is a thermosetting adhesive. The liquid crystal is liquid-tightly sealed between the peripheral edges of the two opposing substrates from above the coating layer, and the bypass electrode has an inscribed isthmus at the inner end of the seal;
The electrode has a circumferential twill at its outer end, and the covering layer has inner and outer via holes corresponding to the inner and outer circumferential twills of the bypass electrode, respectively. The liquid crystal display element is constructed such that the holes are electrically connected to the inner and outer circumferential parts, respectively, and the electrodes have lead-out terminals at the outer ends of the seal.

[For production]

As mentioned above, in conventional liquid crystal display elements, electrodes made of transparent thin films that are easily disconnected are provided on top of the covering film, and a seal is placed on top of the electrodes, so if an abnormal external force is applied, the electrodes However, in the present invention, a bypass electrode is provided so that continuity can be maintained even if the electrode is disconnected.

That is, in the first invention, a strong shunt electrode made of a metal conductor is provided on the substrate below the electrode via a covering layer, and the connection between the electrode and the shunt electrode is made between the inside of the seal of the covering layer and the shunt electrode. Inner and outer via holes are provided on the outside, respectively, and the process is carried out through these via holes.

Then, a seal is provided on the bypass electrode, and even if the electrode is disconnected due to external force such as compression, tension, or twisting applied to the coating layer by the seal, the electrode will be disconnected from the inner via hole to the inner connection part to the bypass electrode. −External connection part first external via hole−
Continuity is maintained through the lead-out terminal.

Next, in the second aspect of the present invention, the surface to which the coating layer is applied extends to the outside of the outer via hole, so that the peripheral edge of the substrate is exposed. Then, the circumscribed twill portion of the bypass electrode is extended to the end surface of the substrate to serve as a lead-out terminal.

In other words, even if the electrode is disconnected due to the seal, the electrode can maintain continuity through the inner via hole, the inner connection part, the bypass electrode, and the lead-out terminal.

This not only provides the same effect as the first invention, but also improves the strength of the lead-out terminal because the bypass electrode is a durable metal conductor film, unlike a transparent conductive film.

Furthermore, in the third aspect of the present invention, the surface to which the coating layer is applied extends to the inside of the seal, and the peripheral edge of the outer substrate is exposed from there. Then, the circumscribed twill portion of the bypass electrode is extended to the end surface of the substrate to serve as a lead-out terminal.

In other words, the electrode is the inner via hole - inner connection part - bypass electrode -
Continuity is maintained via the lead-out terminal. Moreover, the sealing is performed directly on the bypass electrode.

Then, in addition to having the same effect as the first invention and the second invention against disconnection of the electrode caused by the seal and improvement in the strength of the lead-out terminal, the bypass electrode in which the seal is a strong metal conductor film The sealing effect of the seal is also increased.

〔Example〕

FIG. 1 is a sectional view of the main parts of the first embodiment of the present invention, and FIG.
The figure is a partially cutaway plan view of Fig. 1, Fig. 3 is a sectional view of the main part of the second embodiment of the present invention, and Fig. 4 is a sectional view of the main part of the third embodiment of the invention. It is.

In the figure, l is the substrate, 1a is the color filter layer, 2 is the covering layer, 2a is the inner via hole, 2b is the outer via hole, 3 is the electrode, 3a is the lead-out terminal, 4 is the bypass electrode, and 4a is the internal isthmus. , 4b is a circumscribed twill portion, 5 is a seal, 6 is a liquid crystal, 7 is an alignment film, and 9 is a liquid crystal display element.

The substrate 1 is a transparent and smooth glass plate, and on it is a tod-shaped color filter layer 1a of three colors of cyan, yellow, and magenta.
They are alternately lined up and coated with a pinch of mm.

A shielding film 1b made of, for example, chromium is provided in the gap between the color filter layers 1a to prevent light from leaking. The substrate 1 configured in this way is commercially available.

In the substrate 1 on which the color filter layer 1a is provided, the color filter layer 1a is uneven and the shielding film 1b is also a conductor, so the electrode 3 cannot be provided as is.

Therefore, a coating layer 2 made of polyimide having a thickness of 2 μm, for example, is deposited to fill in the irregularities of the color filter layer 1a and make the surface smooth.

On this coating layer 2, an ITO film with a thickness of several nm is placed on an electrode 3.
It is established as

This ITO film is etched in a stripe shape with a pinch of 0.33 mm and a pattern width of 0.3 mm in the X direction or Y direction, and when the two substrates 1 are stacked facing each other,
The intersection of the electrodes 2 overlaps the color filter layer 1a, forming a so-called matrix electrode structure, forming a pixel of, for example, 640 x 400 dots.

Further, the end portion of the electrode 3 provided around the substrate 1 has a pattern width narrower than that of the electrode 3, for example, a pattern width of 0.
It is a 2 mm lead-out terminal 3a, and is connected to an external drive circuit using an elastic connector or the like (not shown).

The seal 5 is made by placing the two substrates 1 facing each other with a gap of about 10 μm, for example, and leaving the injection port for the liquid crystal 6 and connecting the lead-out terminal 3.
It is applied with, for example, an epoxy-based thermosetting adhesive so as to go around the substrate 1 with a width of, for example, 1 mm inside the area a.

Then, when the liquid crystal 6 is injected under vacuum, the injection port is liquid-tightly sealed and the liquid crystal display element 9 is completed.

Example: l In FIGS. 1 and 2, a bypass electrode with a length of 2.5 mm is placed on the substrate 1, opposite the striped electrode 3 provided on the covering layer 2 and crossed by the seal 5. It is provided by etching a deposited Ni/Cr film.

The coating layer 2 coated on the substrate 1 has a bypass electrode 4.
Inscribed isthmus 4a located inside the sea 7C15 at the end of
For example, 0.25 mm is etched by etching so that each of the circumscribed isthmus portions 4b located on the outside of the seal 5 are exposed.
An inner via hole 2a and an outer via hole 2b of mmφ are provided.

Then, when the ITO film is applied to the entire surface of the coating layer 2 and etched in a striped pattern to form the electrode 3, the internal and external isthmus portions 4a and 4b of the bypass electrode 4 are passed through the internal and external via holes 2a and 2b, respectively. is designed to be conductive.

Therefore, if the seal 5 is made to cross the center part of the bypass electrode 4, even if the electrode 3 is disconnected due to the external force of the seal 5, the inner via hole 2a-inner connection part 4a→the bypass electrode 4-
Continuity can be maintained through the circumscribed isthmus portion 4b - external via hole 2b = lead-out terminal 3a.

Embodiment 2 In FIG. 3, the tip of the bypass electrode 4 from the circumscribed isthmus 4b is narrowed to a pattern width of 0.2 mm and extended to form a lead-out terminal 3a.

Then, the covering layer 2 is applied to the outside of the outer via hole 2b so that the lead-out terminal 3a at the end of the substrate 1 is exposed.

In this way, even if the electrode 3 is disconnected, the inner via hole 2a
Conductivity can be maintained through - internal connection part 4a - side path electrode 4 - circumscribed isthmus part 4b - lead-out terminal 3a. Moreover, the lead-out terminal 3a is made of a metal film with high film strength.

Example 3 In FIG. 4, similarly to Example 2, the tip of the circumscribed isthmus 4b of the bypass electrode 4 is narrowed to a pattern width of 0.2 mm and extended to form a lead-out terminal 3a.

On the other hand, the covering layer 2 is applied to the outside of the inner via hole 2a so that the bypass electrode 4, the circumscribed isthmus 4b, and the lead-out terminal 3a connected thereto are exposed.

The seal 5 is applied directly to the center of the bypass electrode 4.

In this case, since the seal 5 is formed directly on the substrate 1 and the bypass electrode 4, stronger sealing can be achieved than in the first and second embodiments in which the seal 5 is formed on the covering layer 2.

The pitch and pattern width of the color filter layer, electrodes, lead-out terminals, etc. can be modified in various ways depending on the purpose for which the liquid crystal display element is used as an LCD.

Furthermore, various modifications can be made to the materials and film thicknesses of the covering layer, electrodes, bypass electrodes, alignment films, liquid crystals, and seals.

〔Effect of the invention〕

As mentioned above, in the past, the coating layer provided to smooth out the unevenness of the color filter layer was not a rigid film, which caused electrode breakage from time to time due to the external force of the seal. In the present invention, a bypass electrode is provided to bypass the electrode, and even if a disconnection occurs in the electrode, continuity between the electrode and the lead-out terminal can be maintained.

Therefore, the present invention is highly effective in improving the yield of the manufacturing process of liquid crystal display elements and the reliability of the product.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the main part of the first embodiment of the present invention, Fig. 2 is a partially cutaway plan view of Fig. 1, and Fig. 3 is the main part of the second embodiment of the invention. 4 is a cross-sectional view of the main parts of the third embodiment of the present invention, FIG. 5 is a cross-sectional view of the structure of an example of a conventional color liquid crystal display element, and FIG. 6 is a cross-sectional view of the main parts of the third embodiment of the present invention. It is an enlarged sectional view. In the figure, 1 is the substrate, 2 is the covering layer, 2b is the outer via hole, 3 is the electrode, 4 is the bypass electrode, 4b is the circumscribed isthmus, 1a is the color filter layer, 2a is the inner via hole, 3a is the lead-out terminal, 4a is an internal isthmus, 5 is a seal, and 6 is a liquid crystal. Cross-sectional view of the main part of the third cusps 1 of the third closed example of the present defense in the second practical example ￥4 Figure 1 Sub-Figure 2 9; Exchange crystal display element ＼Conventional color crystal display element/) - 1 row of cylindrical plates □Figure 5Figure 6

Claims (1)

[Claims] 1) A substrate (1), a covering layer (2), an electrode (3), a bypass electrode (4), and a seal (5), the substrate (1) comprising: It is made of a transparent glass plate, and a color filter layer (1a) made of a transparent thin film colored in each of the three primary colors is deposited in a scattered manner, and the coating layer ( 2) is a transparent insulating thin film that smoothes the unevenness of the color filter layer (1a), and the coating layer (2) is coated on the entire surface of the substrate (1); The electrode (3) is a transparent conductive thin film that is applied to the coating layer (2), and
The bypass electrode (4) is a conductive thin film, and the bypass electrode (4) is a conductive thin film, and the bypass electrode (4) is a conductive thin film.
3) faces the substrate (1) with the coating layer (2) in between.
), and the seal (5) is a thermosetting adhesive that is applied to the peripheral edges of the two opposing substrates (1) from above the coating layer (2). The liquid crystal (6) is sealed in a liquid-tight manner, and the bypass electrode (4) has an inner connection part (4a) at the inner end and an outer end of the seal (5). External connection part (4b
), and the coating layer (2) has inner and outer via holes (2a, 2b) corresponding to the inner and outer connection parts (4a, 4b) of the bypass electrode (4), respectively. In the electrode (3), the inner and outer via holes (2a) and 2b) are connected to the inner and outer via holes (2a and 2b).
The electrode (3) is electrically connected to the external connection portions (4a, 4b), and the electrode (3) has a lead-out terminal (3a) at the outer end of the seal (5). A liquid crystal display element. 2) It has a substrate (1), a covering layer (2), an electrode (3), a bypass electrode (4), and a seal (5), and the covering layer (2) is connected to the outer via hole ( 2b) is attached so that the substrate (1) on the outer periphery is exposed, and the bypass electrode (4) is such that the external connection portion (4b) extends to the end of the substrate (1). The liquid crystal display element according to claim 1, characterized in that the lead-out terminal (3a) is extended. 3) It has a substrate (1), a covering layer (2), an electrode (3), a bypass electrode (4), and a seal (5), and the covering layer (2) has a seal (5). The inner board of (
1) It is coated on the entire surface, and the bypass electrode (
4) has the inner connection part (4a) at the inner end of the seal (5) and the lead-out terminal (3a) whose outer end extends to the end of the substrate (1). and the coating layer (2) covers the internal connection portion (of the bypass electrode (4)).
4a), the electrode (3) has an inner via hole (2a) electrically connected to the inner connection part (4a), The seal (5) seals the liquid crystal (6) between the peripheral edges of the two opposing substrates (1) from above the bypass electrode (4) in a liquid-tight manner. The liquid crystal display element according to claim 1.