JPH02268870A - Method for forming pattern of thick film - Google Patents

Abstract

PURPOSE:To improve productivity and to obtain the good accuracy of a line width by forming prescribed patterns on a substrate by one time of application of the thick film of photosensitive paste, then calcining the thick film to decompose and scatter the photosensitive component, thereby forming the patterns consisting of only the inorg. component. CONSTITUTION:The thick film of a photosensitive paste 4 is applied at one time on a substrate 1 consisting of glass, ceramics, etc., by using a blade coater 3 and is irradiated with UV rays through a mask 5 having the prescribed patterns, by which the photosensitive paste 4 is cured. The paste is developed in succession to form the patterns; thereafter, the patterns of the photosensitive paste 4 are calcined to decompose and scatter the photosensitive component and to form the patterns consisting of only the inorg. component in the final. As a result, the productivity is improved and the yield is improved by one time of the application of the thick film of the photosensitive paste 4. The degradation in the accuracy of the line width by sagging is prevented and the method for forming the thick film patterns without using hydrofluoric acid in the case of a glass etching is obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thick film pattern forming method in the manufacturing process of liquid crystal display devices, fluorescent display tube display panels, plasma display panel-hybrid integrated circuits, etc. be.

[Prior Art] Conventionally, this type of thick film pattern forming method involves printing conductor or insulator paste on a glass or ceramic substrate in a pattern by screen printing, and then drying and printing the paste. A method of forming a thick film pattern by firing is known. Regarding spacers used in plasma display panels, in addition to screen printing, a thick film pattern is also formed by forming a resist layer on a thin glass and etching it.

[Problems to be Solved by the Invention] In the conventional screen printing method described above, when forming a thick film pattern, a method is adopted in which overprinting is performed by multiple times of screen printing to obtain a predetermined thickness. but,
In screen printing, for example, in order to obtain a thick film of 50 to 100 μm, overprinting is required 5 to 10 times, and a drying process is required each time, resulting in extremely poor productivity and a reduction in yield. there were. Furthermore, there is a problem in that sag occurs due to the viscosity, thixotropy, etc. of the paste, and the line width accuracy of the pattern is lost. Furthermore, the method of forming and etching a resist layer on a thin glass sheet has the problem that it is dangerous because a hydrofluoric acid solution is used as the etching solution.

The present invention was devised in order to eliminate the drawbacks of the prior art, and it improves productivity, increases yield, and provides good line width accuracy while reducing the thickness without causing any operational hazards. The purpose of this invention is to provide a method for forming a film pattern.

[Means for Solving the Problems] In order to achieve the above object, the thick film pattern forming method of the present invention forms a thick film of photosensitive paste on a substrate made of glass, ceramics, etc. in one step using a blade coater. The photosensitive paste is cured by applying ultraviolet rays through a mask having a predetermined pattern, followed by development to form a pattern, and the pattern of the photosensitive paste is baked to form an organic substance. By decomposing and scattering the photosensitive component, a pattern consisting only of inorganic components is finally formed.

[Function] In the thick film pattern forming method configured as described above, a photosensitive paste is applied onto a glass or ceramic substrate using a blade coater. Forms a film. After that, a predetermined pattern is obtained by photolithography.

That is, using a blade coater with a blade shape that suits your needs, a photosensitive paste is applied all over a glass or ceramic substrate to form a thick film in one operation, and then passed through a mask with a predetermined pattern. The photosensitive paste is cured by irradiation with ultraviolet rays, then developed to remove the unirradiated areas of the photosensitive paste to form a pattern, and then fired in a baking furnace to form a thick film pattern made only of inorganic materials. do.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

FIG. 1 is a process diagram for explaining the thick film pattern forming method of the present invention, in which (a) shows the process of applying a photosensitive paste, (b) shows the ultraviolet irradiation process, and (C) shows the developing process. ing.

First, the photosensitive paste used in the present invention includes a glass frit such as borosilicate glass, a thermosetting photosensitive resin,
It is a mixture of an organic binder resin and an organic solvent or water, to which various heat-resistant pigments and the like are added as necessary. In order to obtain further conductivity, a noble metal powder such as Au, Ag, or u-Pt is added. In addition, the photosensitive resin of the photosensitive paste used here is a material that undergoes a curing reaction with light in the ultraviolet region, and its main components are acrylic, urethane, epoxy, synthetic rubber, polyvinyl alcohol, etc. These include various resins, rubbers, and gelatin, and each can be used alone or in combination. In order to impart photocurability to these, a reactive diluent, a photoinitiator, a photosensitizer, etc. are added as necessary. Here, the thixotropy of the paste is preferably as low as possible in order to obtain a flat paste application surface.

In the method of the present invention, as shown in FIG. 1(a), this photosensitive paste is first applied onto a glass or ceramic substrate. In the example, a glass substrate 1 with a thickness of 2 mm is scrubbed with a neutral detergent, dried with IPA steam, placed on a substrate support 2, and then coated with a blade coater 3 at a speed of 2 cII/sec. , Photosensitive paste 4 was applied. As the blade coater 2, for example, JP-A-63-I? A coater such as that shown in Japanese Patent No. 1666 may be used. FIG. 2 shows a cross-sectional view of one example. Here, reference numeral 7 denotes a blade mounting frame, which is attached to a movable stand which is held so as to be movable on rails arranged on both sides of the substrate support stand 2 so as to be vertically adjustable. A blade 9 is attached to the lower surface of the blade 9 with bolts 8, and a gap gauge 10 is attached to both ends of the blade 9 with gauge attachment fittings 11 so that the tension can be adjusted.

Here, as shown in FIG. 3, the relationship between the thickness of the gap gauge of the blade coater and the coating thickness is determined in advance, and the gap gauge 10 is selected in accordance with the relationship to obtain a predetermined film thickness. Further, the viscosity of the photosensitive paste is adjusted as necessary to make it suitable for coating.

For example, an organic solvent-diluted paste is prepared by diluting it with an appropriate organic solvent such as a hydrocarbon, ester, or ketone, and a water-diluted paste is prepared by diluting it with water. In this example, the coating thickness is 120
In order to obtain a viscosity of 200 μm, a gap gauge 10 of 200 μm was used, and as a photosensitive paste, a photo insulator (black pigment type) manufactured by Tokyo Ohka was used. a
Butylcarpitol acetate was added to adjust the temperature to 25°C.

After applying the photosensitive paste with a blade coater to form a thick film, drying is performed at 50 to 150°C for about 10 minutes to 2 hours in order to evaporate the organic solvent component or water in the photosensitive paste as necessary. . In this example, 8
Drying was performed at 0°C for 20 minutes.

Then, as shown in FIG. 1(b), an ultraviolet irradiation step is performed.

First, a mask 5 such as a film mask or a chrome mask having a desired pattern is brought into close contact with the surface of a photosensitive paste coated on a glass or ceramic substrate, and ultraviolet rays are irradiated from the top surface of the mask. As a light source, a device using an ultra-high pressure mercury lamp, a metal halide lamp, etc. can be used, and the light source is appropriately selected and used depending on the wavelength to which the photosensitive paste is sensitive. In this case, a filter may be used if necessary. In addition, there are two types of ultraviolet irradiation devices: surface irradiation type and line irradiation type (concentration type), but the thicker the photosensitive paste is, or the more pigment it contains, the more difficult it is for the light to reach the bottom of the photosensitive paste. Therefore, a stronger ultraviolet irradiation device is required, and in that sense, a line irradiation type is preferable. It is preferable for the lamp to have a large output, but take into account the heat it generates and use a suitable one. When a line irradiation type device is used, the device is swept over the object to be irradiated. In this example, in order to obtain a line pattern with a line width of 120 μm, the mask 5
A chrome mask with a line width of 100 μm was prepared, and it was brought into close contact with the film surface of the photosensitive paste, and an ultra-high pressure mercury lamp (
Approx.
A horizontal sweep was performed three times at a speed of 5 m/min at a distance of cm.

Although it is necessary here, in the case of a glass substrate, repeated irradiation occurs due to ultraviolet rays penetrating from the end surface of the glass, which adversely affects the width accuracy and appearance of the pattern.
As shown in Figure (b), an antireflection layer 6 may be provided on the back surface and end surface of the glass substrate.

After irradiation with ultraviolet rays, a developing process is performed as shown in FIG. 1(c).

As a developing method, immersion, shaking, ultrasonic, or spray development can be selected as appropriate, but in order to completely remove the inorganic components of the photosensitive paste in the unirradiated area,
Spray development in which chemical dissolution is accompanied by an element of physical destruction is preferred. Further, as the developer, an organic solvent type or an aqueous type is used depending on the photosensitive paste. By this development, the ultraviolet irradiated areas that have become insoluble due to the crosslinking reaction remain as a predetermined pattern, and the unirradiated areas are removed. Then, the developer is rinsed off and dried. In this example, 1.1.1-) Lichloroethane was used as the developer, and development was performed for 50 seconds by spray development, washed with water to remove the developer, and dried at 100°C for 1 hour. The pattern was well cut and no paste remained in the unexposed areas.

Finally, it is placed in a firing furnace and heated gradually, and fired at a peak temperature of 500 to 600°C for about 2 hours to decompose and scatter the organic components in the photosensitive paste. A thick film pattern is obtained by forming a pattern. Since a thermosetting photosensitive resin is used as a component of the photosensitive paste, deformation of the thick film pattern does not occur during firing due to softening due to temperature rise. Therefore, even after baking, a pattern equivalent to the pattern after development and drying can be obtained. In this example, the film was placed in a firing furnace and gradually heated, and fired at a peak temperature of 585° C. for 2 hours to obtain a predetermined thick film pattern. When the line width and film thickness were measured, the line width was 120 μm and the film thickness was 100 μm.
A very accurate pattern was obtained, and the pattern cut and linearity were also good.

[Effects of the Invention] Since the present invention is configured as described above, it produces the following effects.

Since a thick film of photosensitive paste of 100 μm or more can be coated in one go using a blade coater, it is possible to significantly improve productivity and decrease in yield due to overprinting to form a thick film.

In the case of overprinting, the work time is long and the applied photosensitive paste spreads laterally due to sag, so detailed quality control such as fineness of a predetermined line width is required in advance.However, the method of the present invention According to this method, the coating operation is done only once, so there is no need for it, and there is no need to worry about deterioration in line width accuracy due to sag.

Furthermore, the problem of operational hazards associated with the use of hydrofluoric acid solutions when etching thin glass sheets is eliminated.

[Brief explanation of drawings]

Fig. 1 is a process diagram explaining the thick film pattern forming method of the present invention, Fig. 2 is a cross-sectional view of a blade coater used in an embodiment of the present invention, and Fig. 3 is a graph showing the gap gauge thickness of the blade coater and the photosensitive paste. It is a graph showing the relationship between coating thickness. 1...Glass substrate 2...Substrate support stand 3...
・Blade coater 4...Photosensitive paste 5...
Mask 6... Anti-reflection layer 7... Blade mounting frame 8... Bolt 9... Blade
10... Gap gauge 11... Gauge mounting bracket agent Patent attorney Iku Doi Department Fig. 1 (a) (b) ↓ , 5 (C

Claims (1)

[Claims] (1) A thick film of photosensitive paste is applied in one step onto a substrate made of glass, ceramics, etc. using a blade coater, and the photosensitive paste is cured by irradiating it with ultraviolet rays through a mask with a predetermined pattern. , followed by development to form a pattern, and then firing the pattern of the photosensitive paste to decompose and scatter the organic photosensitive component, thereby finally forming a pattern consisting only of inorganic components. Thick film pattern formation method