JPH0222626A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To use resin spacers to obtain a liquid crystal element (LCD) having a high-precision cell gap by using resin spacers obtained by forming a resin coating layer, whose Young's modulus in flexure is lower than that of spacer main bodies, on the surfaces of spacer main bodies. CONSTITUTION:With respect to resin spacers, a resin coating layer 9 whose Young's modulus in flexure is lower than that of spacer main bodies 8 is formed on the surfaces of spacer main bodies 8. Since the pressure for sticking of two electrode substrates in the production process is absorbed by the resin coating layer 9, the cell gap is kept uniform though spacer main bodies 8 are different in diameter; and therefore, color shading hardly occurs even at the time of producing an S-TN type LCD requiring an exact gap precision, and the yield is considerably improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a liquid crystal display element (hereinafter referred to as LCD).
In particular, the present invention relates to LCDs that use resin spacers as spacer particles that regulate the cell gap.

[Conventional technology]

When manufacturing a TN type LCD or the like, a large number of spacer particles having a diameter corresponding to the cell gap are sprinkled on the surface of one electrode substrate, which is made by patterning transparent electrodes on a glass substrate. The substrate and the other electrode substrate are placed on top of each other with a sealing material interposed therebetween, and then pressurized and heated to bond the image electrode substrate together with a predetermined gap maintained. In other words, the finished LCD has uneven cell gaps.
Conventionally, spacer particles have been interposed between the upper and lower electrode substrates to regulate the cell gap. As this type of spacer particles, colorless and transparent spherical resin spacers made of acrylic resin, phenol resin, or the like have been widely used in recent years.

[Problem to be solved by the invention]

However, resin spacers themselves have variations in diameter; for example, in order to secure a cell gap of 7 μm, a resin spacer with a diameter of 7 ± 0.3 μm must be used, so it is necessary to use a resin spacer with a diameter of 7 ± 0.3 μm. However, when resin spacers are used in LCDs that require high cell gap accuracy, there is a problem in that the manufacturing yield is significantly reduced. In other words, T with a cell gap of about 10 μm
In the case of an N-type LCD, color unevenness does not occur even if the gap error is about ±0.5 μm, but when the cell gap is 6 to 7 μm,
- In the case of a TN type LCD, if the gap error is larger than 10.1 μm, color unevenness will occur.

Therefore, it is an object of the present invention to provide an LCD that uses resin spacers and has high cell gap accuracy.

[Means to solve the problem]

In order to achieve the above object, the present invention uses a resin spacer in which a resin coating layer having a bending elastic modulus smaller than that of the spacer body is formed on the surface of the spacer body.

[Effect]

According to the above means, since the resin coating layer absorbs the pressing force when the two electrode substrates are bonded together, the possibility that variations in the diameter of the spacer bodies cause variations in the cell gap is reduced.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a sectional view of a main part of an LCD according to an embodiment of the present invention, in which a liquid crystal 2 is sealed between upper and lower electrode substrates 1.1, and resin spacers are used as spacer particles to regulate the cell gap. A large number of 3 are interposed.

Each electrode substrate 1 includes a glass substrate 4, an undercoat 5 made of Stow to prevent the Na component of the glass from melting into the liquid crystal, a transparent electrode 6 made of ITO and having a predetermined shape corresponding to a display pattern, and a transparent electrode 6 made of ITO and made of polyimide or the like. Transparent electrode 6 consisting of
The surface of the alignment film 7 is rubbed in a specific direction. and,
The picture electrode substrates 1.1 are stacked together via a sealing material (not shown) and integrated by applying pressure and heating, but prior to this bonding process, a resin spacer is placed on one electrode substrate 1. A predetermined cell gap is secured by these resin spacers 3.

The resin spacer 3 is formed by sputtering a resin coating layer 9 having a lower bending elastic modulus than the spacer body 8 on the surface of a spherical spacer body 8.The spacer body 8 is made of acrylic resin or phenol resin. For the resin coating layer 9, polytetrafluoroethylene resin (hereinafter referred to as PTFE resin) or polyvinylidene fluoride resin (hereinafter referred to as PVDF resin) was used. Here, the bending elastic modulus of the spacer body 8 was set to 5 to 10 kg/cn'', and the bending elastic modulus of the resin coating layer 9 was set to 2 to 5 kg/am''.

When such a resin spacer 3 is interposed, the pressurizing force when bonding the two electrode substrates 1, 1 together is absorbed by the resin coating layer 9, so even if the diameter of the spacer body 8 varies, However, there is almost no possibility that such variations will cause variations in the cell gap, and the gap accuracy is greatly improved.

Figure 2 shows the results of measuring the relationship between the bending elastic modulus of the resin coating layer and the gap error. A resin coating layer with a modulus of elasticity was formed to a thickness of 1 μm by sputtering, and each of these multiple types of resin spacers was coated on an LCD.
This is a measurement of the gap error during manufacturing. Here, the resin coating layer with a bending elastic modulus of 1 to 3 kg/am" is made of PTFE resin, and the bending elastic modulus is 4 to 5 k/am".
g/am” resin coating layer is made of PVDF resin.

As shown in Figure 2, when the bending elastic modulus of the resin coating layer is 3 kg/cm'', the gap error is ±0.05 μm.
The cell gap can be suppressed to 7.0±0.
It was possible to obtain an LCD with an extremely high gap precision of 0.05 μm.

Figure 3 shows the results of measuring the relationship between the thickness of the resin coating layer and the gap error. Considering the film thickness so that the cell gap is 7 μm, PTFE resin (flexural modulus is 3k) is used.
g/cm"), and for each of these multiple types of resin spacers,
This is a measurement of the gap error during manufacturing. In other words, the film thicknesses are 1.5 μm, 1.5 μm, and 1.5 μm, respectively, on the surface of spacer bodies with particle sizes of 5.5 μm, 6.0 μm, and 6.5 μm.
A resin coating layer with a particle size of 0 μm and 0.5 μm was formed by sputtering, and for comparison, a resin coating layer with a particle size of 7.0 μm was formed.
No resin coating layer was formed on the spacer body, and four types of LC were prepared using the four types of resin spacers obtained in this way.
D was assembled and the gap error of each LCD was measured.

As shown in Figure 3, when securing a cell gap of 7 μm, a film thickness of 1.0 μm is applied to the surface of the spacer body with a grain size of 6 μm.
By using a resin spacer formed with a .mu.m resin coating layer, the gap error could be suppressed to ±0.1 .mu.m or less, and an LCD with extremely high gap accuracy could be obtained.

In addition, from the measurement results in Figures 2 and 3, the cell gap is 6~
When manufacturing a 5-TN LCD that requires a gap error of ±0.1 μm or less at 7 μm, the bending elastic modulus of the resin coating layer should be 2 to 4 kg/cm” and the film thickness should be 0.
．． 5-1.5. It is desirable to set it to czm.

In addition, PTFE resin or PVD can be used as the resin coating layer.
Other than the F resin, polychlorotrifluoroethylene resin may be used, or commercially available Microvar (manufactured by Building Block Fine Chemical Co., Ltd.) may be used as the spacer body.

〔Effect of the invention〕

As explained above, according to the present invention, an LCD is constructed using a resin spacer formed by forming a resin coating layer on the surface of the spacer body, and when bonding two electrode substrates together in the manufacturing process. Since the resin coating layer absorbs the pressurizing force, uniformity of the cell gap can be ensured even if there are variations in the diameter of the spacer body, which makes it suitable for 5-TN type LCDs that require strict gap accuracy.
It also has the effect of significantly improving the yield rate, since color unevenness does not occur when manufacturing.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an LCD according to an embodiment of the present invention;
FIG. 2 is a characteristic diagram showing the relationship between the bending elastic modulus of the resin coating layer and the gap error, and FIG. 3 is a characteristic diagram showing the relationship between the film thickness of the resin coating layer and the gap error. ■... Electrode substrate, 2... Liquid crystal, 3...
... Resin spacer, 8 ... Spacer body,
9...Resin coating layer. Figure 1 Figure 2 Figure 2.

Claims (1)

[Claims] In a liquid crystal display device in which a large number of resin spacers are interposed between two electrode substrates to regulate the cell gap, the resin spacer is coated on the surface of the spacer body with a resin coating having a bending elastic modulus smaller than that of the spacer body. A liquid crystal display element characterized by using a layered display element.