JPH0439651B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a liquid crystal display element in which the distance between substrates is extremely small, such as when using a smectic liquid crystal.

[Prior art] Twisted nematic type (hereinafter referred to as TN type) conventionally used in watches, calculators, etc.
Liquid crystal display elements are made of glass with a transparent conductive film formed on it,
After applying a thermosetting adhesive such as epoxy resin to the periphery of a substrate such as plastic film using screen printing, the pair of substrates are bonded together with a distance of about 10 μm, and the adhesive is heated and cured. It was manufactured by

[Problems to be Solved by the Invention] This manufacturing method of applying a thermosetting adhesive by screen printing has a thickness of about 10 μm.
This method is effective for TN type liquid crystal display elements that require
Various inconveniences occur in liquid crystal display elements that require m. In other words, in the screen printing method, the thickness of the applied adhesive is several tens of microns.
Since the coating becomes thick (m), the thin gap described above cannot be obtained unless pressure is applied with a large load after coating. In addition, in the screen printing method, since the surface to which the adhesive is applied is uniformly pressurized by a squeegee, alignment deterioration is likely to occur, and the residue of the stainless mesh is observed as alignment unevenness. Furthermore, when thermosetting adhesives such as epoxy resins are used, the viscosity of the resin decreases during heat curing, and it may flow into the display area, but this tendency becomes even more likely as the gap between the boards becomes smaller. becomes significant and the defective rate increases.

[Object of the Invention] An object of the present invention is to provide a method for manufacturing a liquid crystal display element that allows cells with a small gap between substrates to be manufactured with high yield and good mass productivity.

[Means for explaining the problem] The means of the present invention for achieving the above object is that when a pair of substrates is bonded together to form a cell, the height of the transparent electrode and the liquid crystal alignment film is 1 to 2 μm. An ultraviolet curable adhesive is applied by letterpress printing onto the glass substrate on which spacers are formed, another glass substrate is placed on top of the glass substrate, and a cell is created by irradiating ultraviolet rays, after which liquid crystal is sealed. It is characterized by

[Function] By the above means, the adhesive can be applied and formed extremely thinly and uniformly without rubbing the liquid crystal alignment film on the glass substrate, so that liquid crystal display elements having a cell thickness of 1 to 2 μm can be produced without alignment deterioration and with high yield. Can be manufactured well.

[Example] Next, a specific example of the present invention will be described with reference to the drawings.

As shown in FIG.
1 is prepared, and an ultraviolet curable resin 12 is embedded in the recessed portion of its surface using a squeegee 13. Then, a relief plate 14 made of, for example, rubber is pressed onto the surface of the surface plate 11, and the ultraviolet curing resin 12 is applied to the convex surface 14a. In this state, the letterpress 14 is placed on a substrate 15 such as glass.
is pressed to transfer the ultraviolet curing resin 12 adhering to the convex surface 14a onto one substrate 15. As a result, a coating film 16 of the ultraviolet curable resin 12 is formed on the surface of the substrate 15. This coating film 16 is extremely thin and uniform compared to the case of screen printing. Note that 17 is a spacer previously formed on the substrate 15.

Next, as shown in FIG. 2, the other substrate 18 is superimposed on the substrate 15,
The ultraviolet rays 10 are irradiated while the substrates 15 and 18 are pressurized by 9 and 19 to form the ultraviolet curable resin 1.
Cure 2.

In this way, the substrate 15 and the substrate 18 are bonded together with a predetermined gap maintained by the spacer 17, and the periphery is sealed with the ultraviolet curing resin 12 to form a cell. A liquid crystal display element can be manufactured by sealing liquid crystal inside this cell.

Although the explanation is omitted, transparent electrodes and alignment films are previously formed on the inner surfaces of the substrates 15 and 18.

Example 1 Lock Tight 352UV resin (trade name, manufactured by Nippon Lock Tight Co., Ltd.) was uniformly applied on a surface plate with an unevenness of approximately 10 μm, and then a rubber pattern with a pattern width of 0.5 mm was applied to the coated surface. The plate was pressed and resin was applied to the convex surface. Then, this rubber plate was pressed against a glass substrate on which a transparent electrode, a liquid crystal alignment film, and a spacer had been formed in advance to transfer the resin.

Another glass substrate, on which a transparent electrode and a liquid crystal alignment film had been formed in advance, was placed on top of the glass substrate, and pressure was applied from above and below using another pair of glass plates. In this state, the resin was cured by irradiating ultraviolet rays for 4 minutes using a Minicure UV-450 ultraviolet irradiator (manufactured by Ushio Electric Co., Ltd.). Thus, about
A cell with a uniform spacing of 1.5 μm was formed. Then, a smectic liquid crystal was sealed inside this cell to manufacture a liquid crystal display device.

[Effects of the Invention] As explained above, according to the present invention, ultraviolet curable adhesive is formed by letterpress printing on a glass substrate on which a transparent electrode, a liquid crystal alignment film, and a spacer having a height of 1 to 2 μm are formed. After coating the glass substrate with a liquid crystal, another glass substrate was placed on top of the glass substrate, a cell was created by irradiating ultraviolet rays, and liquid crystal was then encapsulated. Apply adhesive extremely thinly and evenly without
Since it can be formed, liquid crystal display elements having a cell thickness of 1 to 2 μm can be manufactured with good yield without alignment deterioration.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the process of applying an ultraviolet curable adhesive to a substrate by letterpress printing, and FIG. 2 is an explanatory diagram showing the process of bonding the substrates together. In the figure, 11 is a surface plate, 12 is an ultraviolet curing resin,
14 is a rubber plate, 15 is a substrate, 16 is a coating film, 17 is a spacer, and 18 is a substrate.

Claims (1)

[Claims] 1. In a method of manufacturing a liquid crystal display element in which a pair of substrates are bonded together to form a cell, letterpress printing is performed on a glass substrate on which a transparent electrode, a liquid crystal alignment film, and a spacer having a height of 1 to 2 μm are formed. A method for producing a liquid crystal display element, comprising: applying an ultraviolet curable adhesive by a method, stacking another glass substrate on top of the glass substrate, irradiating ultraviolet rays to create a cell, and then encapsulating liquid crystal.