JPH0361579A - Method for printing fine pattern - Google Patents

Abstract

PURPOSE:To sufficiently smooth the surface of a fine pattern by supplying a filmlike web having no affinity to printing ink between the fine pattern and the support surface of a smooth and destaticized support plate as a filmlike piece then bringing said pattern and the support plate into pressure contact state. CONSTITUTION:In case of application to the color filter of a liquid crystal color display, a fine pattern is printed on a glass substrate 1 in such a state that micro protrusions and recesses are left on the surfaces of the fine lines 4a, 4b, 4c thereof, and a support plate 6 having smooth surfaces at the opposite sides is plated on a heating surface plate 5 held in heated state and a film material 7 composed of a silicon rubber film, a polymer film having extremely low thermal expansion/contraction, or a film having a release layer applied to the surface thereof is brought into close contact with the entire surface of the support plate 6. When the surface of the transferred fine pattern is brought into contact with the surface having the release layer applied thereto along with the glass substrate 2, the glass substrate 2 is heated by the heating action of the heating plate to suppress curing of the printing ink of the fine pattern and the uneven surface the fine pattern is leveled and smoothed. As a result, the surface of the fine pattern can be sufficiently smoothed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) This invention relates to a method for printing fine patterns, particularly for printing fine patterns in electric or electronic components such as color filters for liquid crystal displays that require precision printing. This invention relates to improvements in printing methods.

(Prior art) Printing the fine patterns described above requires extremely high precision.For example, in the case of color filters for liquid crystal color displays, fine white lines of three primary colors or four colors of three primary colors and black are printed. An intaglio offset printing technique is employed to print a continuous pattern onto the surface of a transparent inorganic glass substrate.

This printing technique prints a required fine pattern by transferring printing ink transferred from a printing plate such as an intaglio plate or a planographic plate to a blanket onto the substrate to be printed, but the fine lines that make up the fine pattern are Since the pixels in the shape of the image are composed of the so-called RGB three primary colors of red, blue, and green, or the four colors with black added to them, there are variations in the transfer state of individual pixel parts, and as a result, the film thickness of the pixels is uneven. , the fine pattern is printed with a surface that lacks smoothness. If there are minute irregularities on the surface of such a fine pattern, in the case of a color display mounted with liquid crystal drive electrodes, the opposing dimension of the facing interval between the electrode attached to the surface of the fine pattern and the drive electrode There is a risk that differences may occur in the S
In the TN liquid crystal, such uncertainty in the liquid crystal driving operation becomes a fatal flaw. Therefore, conventionally, in order to smooth the surface of the fine pattern of the color filter (electrode mounting surface of the liquid crystal), the finely uneven surface of the surface is polished or rolled using a polishing means or a rolling roll means. A method of obtaining smoothing was adopted, for example, in JP-A No. 6
A technique has been proposed, as disclosed in Japanese Publication No. 2-280804, in which a film is brought into close contact with the surface of the fine pattern of the substrate, and the film is pressed with a rolling roll to smooth the surface of the fine pattern.

(Problems to be Solved by the Invention) As described above, when a polishing means or a rolling roll means is employed to smooth the surface of the fine pattern of the color filter (electrode mounting surface of the liquid crystal), in the former means, In actual work, it is very difficult to polish the entire surface to be polished evenly, and there is also the problem that the performance of the color filter deteriorates due to the residual polishing layer. Although a sufficient effect cannot be obtained unless it is carried out in an uncured state, the technique disclosed in the above-mentioned publication is simply a means of rolling a fine pattern through a film, and the fine pattern is formed. There is a problem in that after the printing ink has hardened, it becomes difficult to achieve the desired smoothing, and this is not a satisfactory solution.

Therefore, this invention is suitable for precision printing that requires fine patterns for color filters and other fine patterns.
Practical for smoothing the surface of a fine pattern (for example, the electrode mounting surface of a liquid crystal in a color filter)
The object of the present invention is to provide a smoothing means that can obtain extremely satisfactory results, and the problem-solving means and specific preferred embodiments will be explained in detail in the following sections.

<Means for Solving the Problems> As described in claim 1, the means for solving the problems of the present invention is a printing method in which a required fine pattern is printed on a substrate by an offset method, in which a blanket attached to a plate cylinder is used. A substrate having a fine pattern transferred from the substrate and a support plate having a smooth support surface,
The transferred fine pattern and the support surface are positioned so as to face each other, and the support plate is supported by a heated surface plate, and printing ink is applied between the fine pattern and the smooth support surface of the support plate. A film-like material having no affinity for the above-mentioned material is cut into appropriate dimensions in a supply path from a supply roll and supplied as a film-like material piece, and the substrate and support plate are pressed together with a required pressure, avoiding any intervening material, The method is characterized in that the surface of the fine pattern is smoothed.

(Operation of the Invention) According to the present invention, a support plate that presses a fine pattern transferred to a substrate is supported by a heating surface plate, and the substrate is also heated via the support plate by the heating by this heating surface plate, The progress of curing of the printing ink constituting the fine pattern is suppressed, the printing ink is rolled by the film-like body while maintaining an uncured state, and the surface of the fine pattern is smoothed.

(Embodiment) The embodiment of the present invention shown in the attached drawings is an example in which the present invention is applied to a color filter for a liquid crystal color display, but the present invention is not limited to only color filters. It should be added that this method is widely applicable to printing fine patterns by precision printing.

In the illustrated embodiment, as shown in FIG. It has an excellent smooth surface, and a fine pattern 4 is applied to one smooth surface. This glass substrate is
facing the back plate on which transparent drive electrodes (not shown) are mounted, with the fine pattern applied on the surface as the inner surface;
A liquid crystal is sealed between the two, and a fine pattern 2 of the substrate is formed.
Transparent electrodes are mounted on the surface of the screen to assemble a color display, but this point is well known to those skilled in the art and is not directly related to the gist of this invention, so the detailed explanation will not be given. The explanation will be omitted.

The formation of the fine pattern 4 on the glass substrate 2 is performed by an intaglio offset printing means, in which the printing surface of the translucent inorganic glass substrate is smoothed, and the printing surface is subjected to intaglio offset printing. A fine pattern of the desired pattern is transferred and printed from the blanket of the device. The obtained fine pattern 4 consists of a large number of consecutive fine lines (width and interval of about 100 μm) of each of the three primary colors of RGB or an intermediate color with black added.
It consists of a color filter pattern with a live pattern, and this transfer is performed by printing ink containing pigment transferred to a blanket from an offset printing plate made by photolithography using a fine pattern through the blanket. Since this transfer printing technique is well known to those skilled in the art, detailed explanation will be omitted.

Glass substrate 1 on which a fine pattern is printed by the above-described method
As shown in FIG. 2A, the fine lines 4a, 4b, and 4c constituting the fine pattern 4 are printed with fine irregularities left on their surfaces. Therefore, the fine pattern is printed continuously after the printing process. Smoothing processing is performed. This smoothing treatment process is performed on a heated surface plate 5 heated at a temperature of about 60 to 70°C, so that both sides of the plate are polished to a completely smooth finish. The support plate 6 having smoothness is cut, and a silicone rubber, silicone polymer, polytetrafluoroethylene, or polyethylene terephthalate film or surface is coated with silicone rubber, silicone polymer, polytetrafluoroethylene, or polyethylene terephthalate, which has extremely low thermal elasticity. A film-like body 7 made of a film (thickness: about 150 μm) provided with a release layer selected from the layers is brought into close contact with the entire surface of the support plate. This film-like body 7 has peelability itself or has a peelable layer formed thereon, and the surface of the transferred fine pattern can be peeled off. The lath substrate 2 of the previous symbol is brought into close contact with the surface on which the i1 layer is applied. This close contact operation is performed while the fine pattern printing ink that has been transferred is not cured, but the glass substrate 2 is heated through the support plate 6 and the film-like body 7 by the heating action of the heating surface plate. The heating suppresses the progress of hardening of the printing ink of the fine pattern during close contact, and the printing ink of each fine line portion constituting the fine pattern 4 is fluid enough to be crushed by the pressing force of the film-like body, As a result, minute irregularities on the surface of the fine pattern are leveled and smoothed, and as shown in FIG. 2B, each fine line 4a, 4b, 4c
The surface is smooth like -.

In this way, due to the close contact between the glass substrate 2 and the support plate 6 with the fine pattern 4 in between, the fine pattern 4 is pressed against the smooth surface of the support plate, and the surface becomes rolled, resulting in ':IiL dipping. However, the press-welding operation is performed on the sandwiched glass substrate 2 and the support plate 6 through a rolling means consisting of a rolling roll 8 and a heating surface plate 5. It is possible to employ means for forcibly passing the sandwich structure through the insertion gap (nip) between the two and press-fitting it.

The insertion gap may be set according to the thickness of the sandwich structure, and the width of the gap where the pressure required for pressure welding is applied is determined according to the thickness of the sandwich structure. A mechanism that applies pressure evenly and evenly over the entire surface may be used.

After the surface of the fine pattern 4 is smoothed, the glass substrate 2 and the support plate 6 are separated. In this separation operation step, the film-like body 7 is peeled off from the fine pattern 4 of the glass substrate 2, but the film-like body 7 in contact with the fine pattern 4
Since it has peelability itself or has a peeling layer, it can be easily peeled off from the fine pattern 4.

In the glass substrate 2 on which the fine pattern 4 has been transferred in this manner, the surface of the fine pattern 4 is smoothed, and a color filter having a fine pattern with a smooth surface is obtained. In the assembled color display, a liquid crystal transparent counter electrode is provided on the N-thin pattern surface of the smoothed color filter, and the opposing distance between the opposing back plate and the drive vJ electrode is constant. structure, resulting in a liquid crystal color display with stable operation.

(Effects of the Invention) According to the present invention, in a printing method for printing a required fine pattern on a substrate by an intaglio offset method, a substrate having a fine pattern transferred from a plate Ill and a support plate having a smooth support surface are provided. 1 to 2 are positioned so that the transferred fine pattern and the support surface face each other,
The supporting plate 1- is supported by a heating surface plate, and a film-like body having no affinity for printing ink is interposed between the fine pattern and the smooth supporting surface of the supporting plate 1-, and the required Since the surface of the fine pattern is smoothed by pressing the substrate and the support plate together with a pressure of Processing can be extremely smooth and effective, making it practical for precision printed matter where smoothing of the surface of fine patterns is extremely important, especially as a printing method that requires precision printing such as color filters for liquid crystal color displays. This has the following effects.

[Brief explanation of drawings]

The drawings show an example in which the present invention is applied to fine pattern printing of a color filter of a liquid crystal color display.
2A and 2B are enlarged cross-sectional views showing the surface condition of each thin line of the fine pattern on the glass substrate, and FIG. 3 shows the press-contact operation between the glass substrate and the support plates 1 to 1. It is an explanatory diagram. 1... Color filter 2... Inorganic glass substrate 3... Back plate 4... Fine pattern 5... Heating surface plate 6... ... Support plate 7 ... Membrane body 8 ... Rolling roll

Claims (2)

[Claims] (1) In a printing method in which a required fine pattern is printed on a substrate by an offset method, a substrate having a fine pattern transferred from a blanket attached to a plate cylinder;
A support plate having a smooth support surface is positioned so that the transferred fine pattern and the support surface face each other,
The support plate is supported by a heating surface plate, and a film-like web having no affinity for printing ink is placed between the fine pattern and the smooth support surface of the support plate in a supply path from a supply roll. Printing of a fine pattern, characterized in that the surface of the fine pattern is smoothed by cutting it into appropriate dimensions, supplying and interposing it as a film-like piece, and pressing the substrate and support plate into contact with a required pressure, thereby smoothing the surface of the fine pattern. Method. (2) The film-like body is silicone rubber, silicone polymer,
It consists of a film of polytetrafluoroethylene, polyethylene terephthalate, or a film whose surface is coated with a release layer selected from silicone rubber, silicone polymer, polytetrafluoroethylene, and polyethylene terephthalate layer, and has the property of having a low heat shrinkage rate. A method for printing a fine pattern according to claim 1, characterized in that: