JPH03251464A - Formation of glaze having paratial projection - Google Patents

Abstract

PURPOSE:To manufacture a high quality high performance glazed substrate which is excellent in printing performance by a method wherein a glazed partial projection is formed by using a photoresist, which is further rounded. CONSTITUTION:After spraying glass powder uniformly onto a ground alumina substrate 1, a smooth glazed layer 2 is formed by baking. Then photoresist liquid is applied onto the surface of this glazed layer, and a resist film 3 is formed by drying. Thereafter, a photomask is put on the resist film, and ultraviolet rays are irradiated. The resist of an unexposed part is removed by developing by further dipping into developer, and the glazed substrate with a resist patter is obtained. By dipping this substrate into etching liquid, an exposed glazed surface part is etched. Then, after sufficiently washing with water, it is dipped into resist peeling liquid, and the resist is throughly peeled off. A rounding process is performed by heat processing of the glazed substrate having respectively formed rectangular partial projections.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Applicability] The present invention relates to a method for forming a glaze on a glazed substrate used in a thermal head, and more specifically, a method for forming a glaze layer on the substrate into a partially convex shape. The present invention relates to a method for forming a glaze having partial convexities formed on a glaze layer.

[Prior Art] In recent years, the demand for thermal transfer printers has been rapidly increasing due to the development and spread of facsimile machines, copying machines, etc., and at the same time, demands for improved printing quality and faster printing speeds have also become stronger. There is.

Therefore, in order to make the glaze surface smooth and defect-free for the glazed substrate used as a thermal head, and to increase the printing pressure between the thermal paper and the heating element, a convex glaze layer is applied on the entire glaze layer. It is particularly requested that such a system be provided. The conventional method for forming such a convex glaze layer is to print glass paste on the entire surface and then
Furthermore, by printing the same glass paste on the convex part and firing it at the same time, or by repeating printing and firing with two types of glass paste with different glass softening points twice, it is possible to create a flat surface. A method of forming a partial glaze layer on the entire surface has been used.

[Problems to be Solved by the Invention] However, the above method attempts to form the required thickness of the glaze and the shape and dimensions of the partial image by firing the printed glass paste once. Due to the shrinkage of the paste due to the removal of organic components during firing, the flow of softened glass, etc., variations occur and the desired accuracy cannot be obtained.
It was extremely difficult to stably manufacture the pitch interval etc. with high accuracy.

Therefore, as a result of various studies regarding the above-mentioned problems, the inventor of the present invention formed a photoresist film on the glaze surface, formed a rectangular partial glaze portion by photoetching, and then heat-treated the glaze to achieve high precision. In high definition,
Moreover, it was discovered that it was possible to easily form a R partial picture, and the present invention was completed based on this finding.

Therefore, an object of the present invention is to provide a method for forming a glaze having partial areas, which can eliminate the above-mentioned conventional drawbacks and produce a glaze substrate for a thermal head with good printing performance, high quality, and high performance. There is a particular thing.

[Means for Solving the Problems] The objects of the present invention are as follows: (1) After forming a photoresist film on a glazed flat layer formed on at least one side of an alumina substrate, the resist film is selectively exposed. The glaze portion exposed by this is immersed in an etching solution to dissolve it, and then the resist film is peeled off, and the resulting partial glaze portion is heat-treated to make it R. A method for forming a glaze having partial fractions.

(2) A method for forming a glaze having partial fractions, characterized in that the etching solution described in item 1 contains at least one of hydrofluoric acid or a mixed acid of hydrofluoric acid and nitric acid, sulfuric acid, or another inorganic acid.

(3) The heat treatments described in Items 1 and 2 were each achieved by a method for forming a glaze having partial fractions, which is characterized by firing at a temperature at least equal to or higher than the glass softening point.

[Specific Structure of the Invention] The glass powder of the glaze material used in the present invention is one that satisfies both the insulation properties and heat resistance (softening point of 800° C. or higher) required for a thermal printer head, and is preferably A1203. -BaO-8203-Ca
O-5iO2 glass is used. This glass powder is deposited on an alumina substrate by printing or spraying, and then fired to obtain a smooth glass layer. Next, a negative photoresist solution is applied onto this smooth glass layer and dried to form a resist film of a desired thickness.The resist film is then exposed to ultraviolet light through a photomask and developed. Remove the resist in unexposed areas.

In this case, the etching resist remains where the partial image is to be formed, and is removed from the area other than the partial image.

The photoresist film is resistant to hydrofluoric acid and acid, and a positive type can also be used.

Therefore, as such photoresists, for example, negative type OMR (manufactured by Tokyo Ohka Kogyo Co., Ltd.) and KMR (manufactured by Tokyo Ohka Kogyo Co., Ltd.) are available.
Rubber resists such as Kodak (manufactured by Kodak), photoresists such as cinnamic acid resists such as TPR (manufactured by Tokyo Ohka Kogyo), and for positive resists, diazo resists such as AZ (manufactured by Shipley) are suitable. .

Further, methods for applying the photoresist solution include a dipping method, a spinner method, and the like, and any of these methods can be used. In addition, dry films can also be used.

Further, as the etching solution for the glaze, hydrofluoric acid alone, a mixture of hydrofluoric acid and sulfuric acid or nitric acid, or a mixture of these and other inorganic acids can be used.

A glazed substrate having a rectangular partial area formed by such photoetching is heat-treated at a temperature higher than the glass softening point to make the partial area rounded (R) in order to prevent disconnection due to the rectangular edges of the glaze. .

This rounding makes the corners of the glaze partial areas rounded.

The height of the partial image can be arbitrarily adjusted within the thickness of the glass layer, and its accuracy is within ±1 μm with respect to the target value.

The heating and firing temperature for R and other treatments must be at least the glass softening point or higher, but it is preferable to carry out the heating under suitable conditions that match the characteristics of the glass material used.

Further, the above-mentioned compositional glass tends to crystallize at a temperature exceeding its softening point, which causes protrusions. therefore,
In order to prevent such protrusions, heat treatment with a profile of 60 minutes or less is required.

Defects on the surface of the glaze are undesirable in electronic circuit boards such as thermal printer heads because they hinder the formation of fine wiring or cause uneven printing by the head. The rounded shape of the partial convex portion can be accurately controlled at R=1 mm or more by the heat treatment temperature, heat treatment time, and the partial convex portion and height before the heat treatment.

[Example] Hereinafter, the present invention will be explained in more detail with reference to Examples.
This does not limit the invention.

FIGS. 1(a) to 1(g) are schematic cross-sectional views showing a method for manufacturing a glazed substrate having partial sections obtained in each step of this example.

First, spray Al203 onto a 96% polished alumina substrate 1 measuring 50 mm x 270 mm and 1 mm thick.
-BaO-8203-CaO-5f02 glass powder was evenly deposited and then fired at a temperature of over 1000°C to form a smooth glaze layer 2 with a thickness of 60 μm on one side. The obtained glazed alumina substrate is shown in FIG. 1(a).

Next, a photoresist solution (manufactured by Tokyo Ohka Kogyo Co., Ltd., OMR-83) was applied on the surface of this smooth and flat glaze layer by a spin cord method, and dried (conditions: 85°C, 30°C).
2) to form a resist film 3. (Fig. 1(b)) Next, a photomask is placed on the resist film, and an exposure device is used to irradiate it with ultraviolet rays (Fig. 1(c)).The unexposed portions of the resist are further immersed in a developer and developed. By removing it, a glazed substrate with a resist pattern as shown in FIG. 1(d) was obtained. This substrate is hydrofluoric acid (45wt%)
The exposed surface of the glaze was etched by immersing it for 2 to 3 minutes (at room temperature) in an etching solution containing a mixture of sulfuric acid (98 wt %) and sulfuric acid (98 wt %) at a volume ratio of 4:1. FIG. 1(e) Thereafter, the resist was thoroughly washed with water and then immersed in a resist stripping solution to cleanly strip the resist.

FIG. 1(f) shows a cross section of the substrate after etching. In this way, a rectangular partial glaze portion is formed in the glaze layer, and in this case, the width and height of the die can be arbitrarily changed depending on the width and etching depth of the resist masking portion.

The glazed substrate having each of the rectangular subdivisions formed in the above manner was subjected to R et al. treatment by heating and baking it for 40 minutes at a maximum temperature of 1000° C. and a holding time of 10 minutes. The shape of the partial area obtained by this R treatment had rounded corners and a rounded shape, resulting in a glazed substrate having a rounded partial area (FIG. 1(g)).

[Effects of the Invention] According to the present invention, a highly accurate partial image can be obtained by forming a partial image of the glaze using a photoresist, and the curvature of the partial image of the glaze can be reduced by further processing this by R and other processes. A glaze substrate with partial areas that can be formed arbitrarily with high precision, is easy to manufacture, and can be manufactured at low cost.Therefore, a glaze substrate for a high-quality, high-performance thermal head with good printing performance can be produced. Can be manufactured.

[Brief explanation of drawings]

(a), (b), (c), (d), (e), (
f) is a cross-sectional view showing the manufacturing process of a glazed substrate having partial areas according to an embodiment of the present invention. Explanation of symbols 1... Alumina substrate 2... 3... Photoresist 4... Exposed photoresist 5... Photoresist after development 6... Etched portion 7... Partial image 8...・R partial image glaze layer

Claims (3)

[Claims] (1) After forming a photoresist film on the glazed flat layer formed on at least one side of the alumina substrate, the resist film is selectively exposed and developed, and the exposed glaze portion is immersed in an etching solution. 1. A method for forming a glaze having partially convex portions, the method comprising: dissolving the resist film, then peeling off the resist film, and heat-treating the resulting partially convex glaze portion to make it rounded. (2) A method for forming a glaze having partial convexities, characterized in that the etching solution according to claim 1 contains at least one of hydrofluoric acid or a mixed acid of hydrofluoric acid and nitric acid, sulfuric acid, or another inorganic acid. (3) A method for forming a glaze having partial convexities, wherein the heat treatment according to any one of claims 1 to 2 is performed by firing at a temperature at least equal to or higher than the glass softening point.