JPH0353252A - Engraving method for precision printing - Google Patents

Abstract

PURPOSE:To suppress the thermal expansion of the machine plate of a metallic plate to be exposed and printed and to improve the accuracy of reproducing the fine patterns formed on the machine plate by providing an absorber in an optical path for exposing rays and absorbing the heat ray components of the exposing rays therein. CONSTITUTION:The absorber 4 which absorbs the heat ray components of a long wavelength region of IR rays, far IR rays, etc., of shielding rays 1 in the optical path for irradiation of the exposing rays 1 for printing of the fine patterns is provided on the machine plate 3 of the metallic plate through a master plate 2. The absorber 4 consists of a glass casing 41 consisting of heat resistant glass such as quarts glass and fluid flowing in this casing 41. The inside of the casing 41 is hollow and the fluid injected from an inflow port 42 formed on the lower side in made to flow from a discharge port 43 on the upper side. Bubbles do not, therefore, enter the inside of the casing 41 and the fluid completely shuts off the optical path for the exposing rays passing the casing 41. The thermal expansion effect of the machine plate 3 is suppressed in this way and the reproduction accuracy of the fine patterns formed on the machine plate 3 is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an improvement in a method for making a precision printing plate for printing precision printing materials such as color filters for liquid crystal color displays.

(Prior art) As the above-mentioned plate-making method, photolithography is generally adopted, and a metal plate (copper plate) on which a photoresist layer is provided is placed directly under and directly under a master plate on which a fine pattern will be formed. However, a method is used in which a metal plate serving as a printing plate is irradiated with exposure light from an exposure light source through a master plate, the required exposure and baking is performed, and the plate is made after undergoing development treatment and corrosion treatment.

(Problems to be Solved by the Invention) In the above plate-making method, a mercury lamp is used as an exposure light source, and the metal plate is heated by the action of the hot rays of the mercury lamp to a temperature of about 3 to 5 degrees Celsius above room temperature. When a copper plate is used as a metal plate that is heated to a high temperature, there is a problem that the copper plate expands due to such heating and the precision of the fine pattern formed on the copper plate decreases. In particular, when the fine pattern is composed of an ultra-fine stripe pattern (stripe width of about 100 μm) in the three primary colors of RGB, such as the color filter of a liquid crystal color display, when the copper plate expands due to temperature rise, it may become smaller than the master plate. It is impossible to reproduce exactly the same fine pattern, and the printing plate is unsuitable for printing fine patterns.

(Means for Solving the Problem) Therefore, this defense provides a plate-making method for precision printing, particularly for obtaining a printing plate that faithfully reproduces the fine pattern of a master plate. As a means to achieve this goal, in a method of making precision printing plates for printing precision printing materials such as color filters for liquid crystal color displays, exposure light is used to print a fine pattern on a metal plate through a master plate. A means to solve the problem is to perform exposure printing by interposing an absorber that absorbs heat ray components in the long wavelength range such as infrared rays and far infrared rays of the exposure beam in the optical path of the sword.

(Operation of the Invention) According to the present invention, the absorber interposed in the optical path of the exposure light absorbs heat ray components in the long wavelength range such as infrared rays and far infrared rays, and the metal to be exposed and baked Prevents the temperature of the printing plate on the plate, suppresses the thermal expansion of the printing plate,
To improve the reproduction accuracy of fine patterns formed on printing plates.

(Embodiment) To explain this invention in detail with reference to the illustrated embodiment, a mercury lamp is used as the exposure light source 1, and a master plate 2 and a printing plate (copper plate) 3 coated with a photoresist layer are placed facing the exposure light source 1.
The point that the exposure light from an exposure light source 1 equipped with a reflector plate 11 is illuminated onto the printing plate 3 through the master plate 2, and the printing plate is made through the steps of exposure and development, and after the etching process is different from the conventional method. Although the process is the same as the above process, in this invention, an absorber 4 for a certain amount of the heat rays of the exposure light is rearranged between the exposure light source 1 and the master plate 2. Further, the exposure light source 1 is surrounded by a channel 12 through which pure water passes. A film 5 is placed around the master plate 2 and the printing plate 3, and the film is sucked through a vacuum hole 7 provided in the contact printing frame 6 and fixed to the contact printing frame 6.

The absorber 4 consists of a glass casing 41 made of heat-resistant glass such as quartz glass, and a fluid flowing inside the glass casing 41.
It has a hollow structure with a planar dimension extending over the entire surface of the baking frame and a relatively low height, and a fluid inlet 42 and an outlet 43 are provided on the lower and upper sides, respectively. The fluid injected from the inlet formed on the side flows from the outlet on the upper side, preventing air bubbles from entering the inside of the glass casing, allowing the fluid to flow over the entire surface, and preventing the exposure light beam passing through the glass casing. The structure is such that the optical path is completely blocked by the fluid.

The fluid flowing through the fluid flow path from the inlet 42 to the outlet 43 has a large dipole moment, such as water or thiourea, and absorbs some of the heat rays in the long wavelength region such as infrared rays and far infrared rays of exposure light. It is a fluid that has the property of transmitting ultraviolet light components involved in photosensitive printing of exposure light, and is supplied from the inlet 42 and flows through the glass casing 41 to the outlet 43 at an appropriate flow rate. During the exposure and printing process, the fluid flowing inside the glass casing 41 is constantly in a running state. The fluid may be supplied from an appropriate supply source to the inlet by a pump and then circulated from the outlet to the inlet again, or by a so-called dripping method.

When exposure and printing are performed on a printing plate in the presence of the heat ray component absorption block 4 as described above, the exposure light from the exposure light source 1 consisting of a mercury lamp first passes through the absorption block 4 and then passes through the master plate 2. The exposure light beam is then directed onto the printing plate 3, the fine pattern of the master plate 2 is printed onto the printing plate, and the printing plate is made through the post-etching process. By passing through the infrared rays,
Heat ray components in the long wave range such as far infrared rays are absorbed, and the heating effect on the master plate 2 and printing plate 3 is drastically reduced, suppressing their thermal expansion effects. Since the master plate is usually composed of a glass plate with a small coefficient of thermal expansion, the suppression of the thermal expansion effect is particularly effective for printing plates with a large coefficient of thermal expansion, such as copper plates, and the heat ray component due to the absorber is Due to the absorption effect, the printing plate is kept at approximately the same temperature as room temperature during the exposure and printing processes, and the fine pattern exposed and printed is faithful to the master plate, and the accuracy of the fine pattern is not distorted. There is no risk of this occurring, and a printing plate suitable for precision printing is produced.

(Effects of the Invention) As described above, according to the present invention, the absorber interposed in the optical path of the exposure light absorbs heat ray components in the long wavelength range such as infrared rays and far infrared rays, thereby improving exposure printing. 1? prevents the temperature rise of the metal plate printing plate, which is the object of It is possible to make a printing plate that improves the reproduction viscosity of fine patterns and allows precision printing to be performed with strict precision.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram illustrating an example of the plate making method of the present invention. 1... Exposure light source 2... Master plate 3... Printing plate 4... Absorber 41... Glass casing

Claims (3)

[Claims] (1) In a method of making precision printing plates for printing precision printing materials such as color filters for liquid crystal color displays, exposure is made in the optical path of exposure light that prints a fine pattern on a metal plate through a master plate. A precision printing plate-making method that performs exposure printing by arranging an absorber that absorbs heat ray components in the long wavelength range such as infrared and far infrared rays. (2) The plate-making method for precision printing according to claim 1, wherein the absorber is arranged in the optical path of the exposure light beam, and is intermediate between the exposure light source and the master plate. (3) The absorber is composed of a glass casing made of heat-resistant glass such as quartz glass, and a fluid with a large dipole moment that absorbs the heat ray component, such as water or thiourea, is circulated in the glass casing. 2. The plate-making method for precision printing according to claim 1, wherein the heat ray component of the exposure light passing through the absorber is absorbed.