JPS63217324A - Method for printing of thin film - Google Patents

Abstract

PURPOSE:To form thin films to a specified film thickness and to eliminate uneven printing by using a letterpress formed with projecting parts for pressure regulation in the side part of projecting parts for printing and regulating the pressing force to printing surfaces in the respective positions in the rotating direction of the projecting parts for printing to the specified force at the time of forming the thin films by the projecting parts for printing of the letterpress provided around a printing drum. CONSTITUTION:The letterpress 12 is mounted on the surface of the cylindrical printing drum 22 consisting of a metal. Said letterpress 12 is constituted of a synthetic resin. Plural pieces of the projecting parts 13 for printing having a longitudinal shape corresponding to prescribed orientation positions and shapes are formed axially in two rows and in the rotating direction on the surface of such projecting parts 12. The projecting parts 14 for pressure regulation are respectively formed between the projecting parts 13 adjacent to the projecting parts 13 of the respective rows in the side parts of the axial direction thereof and in the rotating direction thereof. A moving table 16 holding a glass substrate (a) is moved and the substrate (a) is moved downward of the drum 11. A rubber roller 15 on which the stock soln. for oriented films is dropped is rotated together with the drum 11 in synchronization with the circumferential moving speed of the table 16, by which the nearly constant thin films are printed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a thin film printing method for forming a thin film on a printing surface by letterpress printing.

(Conventional technology) An example of a device in which a thin film is formed is a liquid crystal display.

As shown in Fig. 4, this liquid crystal display consists of two glass substrates a that have been subjected to alignment treatment, facing each other in parallel with a distance of 5 to 10 μm, and then bonding the periphery of the glass substrates a with a sealant. Fix the liquid crystal substance C on the glass substrate a lff1.
As an orientation treatment for the glass substrate a, an alignment film C is applied to the transparent electrode d formed on the glass substrate a. Forms a membrane. In addition to the orientation 11Ae, thin films such as an electrode insulating film, a color filter, and a black mask may also be formed on the glass substrate a.

As a method for forming this thin film, for example, Japanese Patent Laid-Open No. 57-90
As shown in Japanese Patent No. 616, there is a method of forming by letterpress printing.

Conventionally, in forming a thin film by letterpress printing, as shown in FIG. 5, a letterpress plate 3 having a plurality of printing convex portions 2 corresponding to a predetermined oriented blue printing position and shape is provided on a cylindrical printing drum 1. Then, the glass substrate a is sent below the printing drum 1 by the moving table 4, and the moving table 4
The printing drum 1 is rotated by adjusting the circumferential speed to the moving speed of U,
Further, when the printing drum 1 rotates, the undiluted solution of the alignment film is applied to the surface of each printing convex part 2 by contact rotation with the rubber [1-ru 5], and therefore, the undiluted solution of the alignment film is applied to the surface of each printing convex part 2. The undiluted solution is transferred onto the glass substrate 1 to form an alignment film e.

(Problem to be solved by the invention) A by conventional letterpress printing as mentioned above? In film formation,
Since printing is performed by rotating the letterpress 3 provided on the cylindrical printing drum 1, the pressing force when pressing and transferring the printing convex portion 2 onto the glass substrate a is applied at each position in the rotation direction of the printing convex portion 2. In other words, the pressing force is strong at both ends of the printing protrusion 2 in the rotational direction, and a large amount of the undiluted solution of the alignment film is transferred, as shown in FIG. The thickness of each edge of the alignment film 0 corresponding to the area satisfies Fa<<. For example, if the stock solution of the alignment film e is a polyimide solution and the thickness of the film is about 700 to 800, the edges of each edge of the alignment film e will be about 70 to 80 mm thick. The surplus is marked 1f.

Moreover, as shown in FIG. 5, if the shape of the printing protrusion 2 (orientation film e) is not the same in the direction of rotation 1J, but is shaped like a circular or triangular ':A', for example, the shape of the printing protrusion 2 (orientation film e) is Accordingly, the contact area with the glass substrate a changes, and the pressing force on the glass M plate a in each contact device in the rotational direction of the printing protrusion 2 changes, resulting in uneven film thickness of the alignment film C. arise.

This printing unevenness of the alignment film e causes color unevenness in a liquid crystal display such as a ferroelectric liquid crystal, and also causes color unevenness in a normal liquid crystal display.

The present invention was made in view of the above-mentioned problems, and it prints a thin film by keeping the pressing force on the printing surface substantially constant at each position in the rotational direction of the printing convex part of the letterpress, thereby eliminating printing unevenness of the thin film. The purpose of this invention is to provide a thin film printing method that can reduce the amount of printing required.

[Structure of the invention]

(First Step to Solve the Problems) The present invention provides a thin 11Q printing force method in which a thin film is printed on the printing surface by the printing protrusions of a letterpress provided around a cylindrical printing drum. Using a letterpress with pressure adjustment protrusions formed on the sides of the pressure adjustment protrusions, the pressing force on the printing surface kept approximately constant at each position in the rotational direction of the printing protrusions. It is used to print thin films.

(For fl) The present invention prints Nb n') on the printing surface by keeping the pressure angle on the mark 111 surface substantially constant at each position in the rotational direction of the printing convex part by the pressure adjusting convex part. A thin film having a substantially constant thickness is formed.

(''):, 191) Hereinafter, the configuration of an embodiment of the present invention will be described with reference to FIG. 1 Jj and FIG. 2.

For example, a printing driver 1111 made of metal such as SUS
[J Letterpress 12 is written 'A Ft' on the surface. The relief plate 12 is made of, for example, chemically treated synthetic resin, and on its surface, rectangular printing convex portions 13 are arranged in two rows in the direction of the axis 1 and rotated in correspondence with the predetermined position and shape of the alignment film. A plurality of pressure adjusting protrusions 14 are formed in the axial direction, and pressure adjusting protrusions 14 are formed between the printing protrusions 13 adjacent to each other in the rotational direction on the axial side of the printing protrusions 13 in each row. Note that both ends of each pressure adjusting convex portion 14 in the rotational direction are formed to be wider in the rotational direction than the interval between each printing convexity 13 adjacent to each other in the rotational direction, and the edges of each printing convexity 13 in the rotational direction located on the side of the

Reference numeral 15 denotes a rubber roll onto which an undiluted solution of the alignment film, such as a polyimide solution, is dropped, and rotates together with the printing drum 11 to apply the undiluted solution of the alignment film to each printing convex portion 13 of the relief plate 12.

Then, when the moving table 16 holding the glass substrate a on its upper surface is moved and the glass star plate a is sent below the printing drum 11, the moving speed of the moving table 16 is Rotate the printing drum 11 at the same speed,
Also, when the printing drum 11 rotates, the rubber roll 15
The undiluted liquid of the alignment film is applied to the surface of each printing convex part 13 of the letterpress 12 by contact rotation with the plate 12, and the undiluted solution on the surface of each printed convex part 13 is transferred onto the glass V plate a, and the glass bulb is A thin layer of a plurality of alignment films e is printed on the printing surface a.

At this time, the starting end side of the printing protrusion 130 rotation 1 direction and I
When each edge on the I end side contacts the glass Lt plate 31,
Since the pressure adjusting protrusions 14 touch together, the printing protrusions 13
The pressing force applied to each edge of the printing protrusion 13 is reduced and becomes close to the pressing force at the middle part of the printing protrusion 13. Therefore, as shown in FIG. is printed almost constantly.

Furthermore, since the pressure adjustment protrusion 14 is formed between the printing protrusions 13 in the rotational direction, the edge of the printing protrusion 13 next to the printing protrusion 13 that has been transferred is placed on the glass substrate a. When abutting, the sudden application of pressing force to the edge of the printing convex portion 13 is alleviated, and an increase in the thickness of the edge of the alignment film C can be prevented.

In addition, since each pressure adjustment convex part 14 also contacts the glass substrate at, together with each printing convex part 13, an alignment film e1 is printed on the side of the orientation M'A e on the glass substrate a. By providing C1 at a location on the glass substrate a where no electrode is formed or at a location where the electrode is insulated with an insulating film, the liquid crystal display can be prevented from being affected.

Further, as shown in FIG. 3, when the printing convex portion 13 of the relief plate 12 is circular, the horizontal width of the pressure adjustment convex portion 14 is narrowed at the wide center side of the printing convex portion 13, and the printing convex portion 13 is made narrower. The width of the pressure adjusting convex portion 14 is increased at a location where the width of the convex portion 13 on the end side in the rotational direction is narrow, so that the pressing force of the printing convex portion 13 against the glass substrate a is kept constant.

Therefore, irrespective of the shape of the printing protrusions 13, printing unevenness can be reduced by keeping the pressing force of the printing protrusions 13 against the glass substrate a constant using the pressure adjusting protrusions 14.

In addition, the glass substrate a on which the alignment film e was formed by letterpress printing in the above embodiment is used in a liquid crystal display as shown in FIG.
This liquid crystal display consists of two glass substrates (a) that have been subjected to an alignment treatment, which are arranged in parallel to each other with an interval of 5 to 10 μm maintained, and the peripheries of the glass substrates (a) are adhesively fixed using a sealant. A liquid crystal substance C is filled in between. In addition, d
is a transparent electric bridge.

Further, in each of the above embodiments, the mark 8 on the alignment film e of the liquid crystal display
Although the No. 111 method has been explained, it is also possible to apply this printing method when forming makeup on the surface of the liquid crystal display 3, color filters, black masks, etc. It can be applied at the location where the thin film is formed.

〔Effect of the invention〕

According to the present invention, the pressure adjustment convex portion maintains the pressing force on the printing surface at each position in the westward direction of rotation of the C printing convex portion at a substantially constant level.
), it is possible to print a thin film with a substantially constant thickness on the printing surface, and it is possible to reduce printing unevenness of the thin film.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a practical example of the method of printing a film of the present invention, Fig. 2 is a sectional view of a glass substrate used for printing 1,
4 is a sectional view of a liquid crystal display, FIG. 5 is a perspective view showing a conventional thin film printing method, and FIG. It is an n-plane view of a glass substrate. DESCRIPTION OF SYMBOLS 11: Printing drum, 12: Letterpress, 13: Printing convex portion, 14: 5 ■Force adjustment convex portion, a: Glass substrate as printing surface, e: Alignment film as thin film. Mine 11

Claims (2)

[Claims] (1) In a thin film printing method in which a thin film is printed on the printing surface using printing convex portions of a letterpress provided around a cylindrical printing drum, a letterpress plate having pressure adjustment convex portions formed on the sides of the printing convex portions is used. A thin film printing method, characterized in that the thin film is printed by keeping the pressing force on the printing surface substantially constant at each position in the rotational direction of the printing protrusion using the pressure adjusting protrusion. (2) Using a letterpress in which a plurality of printing protrusions are formed in the rotational direction and pressure adjustment protrusions are formed between the printing protrusions, the edges of the printing protrusions in the rotational direction are controlled by the pressure adjustment protrusions. 2. The thin film printing method according to claim 1, wherein the thin film is printed by relaxing the pressing force on the printing surface.