JPH02130155A - Preparation of glazed ceramic substrate for thermal head - Google Patents

Abstract

PURPOSE:To obtain a glazed ceramic substrate having a linear protuberance part whose shoulder part forms a gentle curved surface and whose upper surface has high plane accuracy by forming a glass film on a substrate to pattern the same using a photoresist and applying etching to the patterned glass film to form linear glass layer and forming a glass film thereon by baking. CONSTITUTION:Glass powder paste is applied to the entire surface of a high resistance ceramic substrate 1 and baked to form a glass film 2. This ceramic substrate is mounted on a spinner and a photoresist is applied to the glass film 2 and, after drying, the photoresist layer is irradiated with near infrared rays to be made easily soluble and developed to form a predetermined pattern. The glass film 2 is etched according to the pattern to form a linear glass layer 2a. Next, amorphous glass paste is applied to the entire surface of the substrate having the glass layer 2a formed thereto and baked to obtain a glazed ceramic substrate having a glass film 4 arranged on the glass layer 2a thereof is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method for manufacturing a glazed ceramic substrate for a thermal head, and is particularly used for manufacturing a line-type thermal head for dot printing in a thermal printer.

(B) Prior Art Conventionally, as shown in FIG. 8, a glazed ceramic substrate used in a line-type thermal head for dot printing has a predetermined pattern of glass film 44 formed on a ceramic substrate 11 by a printing and firing method. The glass layer 22 is manufactured by forming a raised glass layer 22 in a predetermined pattern on the glass film 44 by a printing and firing method, as shown in FIG.

The thermal head is manufactured by forming a heating resistor portion on the raised position of the glazed ceramic substrate.

This thermal head is configured so that images on the same line can be printed on transfer paper or thermal recording paper by dividing an image signal into lines to be printed and outputting them.

(c) Problems to be Solved by the Invention The glazed ceramic substrate for thermal heads manufactured using the conventional manufacturing method has poor linear pattern accuracy, with an error of about ±100 μm in normal cases, and when controlled with extremely high precision. However, the limit was ±50 μm. Therefore, in a thermal head made using this glazed ceramic substrate, the line linearity of the heating resistor part that forms the pixel was not sufficient, resulting in insufficient contact with the paper being printed, which could result in printing defects. .

The purpose of this invention is to improve the linearity of the heating resistor formed on the raised part of the glass layer, to equalize the printing power efficiency, to reduce the variation in printing density (ΔD), and to manufacture a thermal head with improved reliability. An object of the present invention is to provide a method for manufacturing a glazed ceramic substrate with high linear accuracy.

(d) Means for Solving the Problems According to the present invention, a glass powder paste is printed and fired on a ceramic substrate for a thermal head to form a glass film, and a photoresist is applied on this to form a glass film. patterning the surface of the glass film, leaving a photoresist at a position corresponding to the heating resistor part of the thermal hept, which is intended for
The glass film is etched according to this pattern to form a linear glass layer, and a paste of glass powder is further printed on this and fired to form a glazed ceramic substrate having linear ridges. A method of manufacturing a glazed ceramic substrate for a thermal head is provided.

In this invention, it is suitable to form a glass film by printing a glass powder paste on a ceramic substrate for a thermal head and firing it.

The ceramic substrate for the thermal head is, for example, A.I.
Insulating ceramics such as 2t Os, Sin, SiO, 5isN4 can be used, for example, 8 buttons vertically and 2 horizontally.
A material having an outer diameter of 70 x m and a thickness of 0.8 cm can be used.

The glass powder is, for example, aluminoborosilicate glass,
Borosilicate glass etc. can be used, and refractory filler PbOlMgO, BaO is added thereto.

It is suitable to use it as a paste by adding CaO, etc., and α-terpineol, ethyl cellulose, etc. as a medium. This glass powder paste is applied onto the ceramic substrate using a printing machine, and then fired at a temperature of usually 600 to 1000°C using, for example, an electric furnace to form a glass film having a thickness of usually 30 to 90 μm. is suitable.

In this invention, a photoresist is applied onto the glass film, the surface of the glass film is patterned leaving the photoresist at a position corresponding to the heating resistor of the thermal head to be formed, and the glass film is formed according to this pattern. Etching to form a straight glass layer is suitable. As the photoresist, a negative type photoresist or a positive type photoresist can be used, and examples thereof include cyclic rubber type, polyvinyl cinnamate type, and novolac resin-〇quinone diazo type photoresists. The photoresist can be applied, for example, by placing the ceramic substrate having the glass layer on a spinner (rotating table) and rotating it at high speed while dropping the photoresist solution. The position corresponding to the heating resistor of the thermal head to be formed is, for example, 1 to 5 points from the lateral end of the ceramic substrate.
A linear position with a width of 1.5 to 5.0 mm is suitable. The photoresist at this location is typically 280-48
The surface of the glass film can be patterned by making it insoluble by irradiating or not irradiating it with light having a wavelength of 0 nm, and then dissolving and removing the remaining easily soluble photoresist.

Next, according to this pattern, the glass film is etched using, for example, an HF-based aqueous solution to form a linear glass layer, usually 30 to 90 μm thick, at a position corresponding to the heating resistor part of the thermal head intended to be formed. can be formed.

In this invention, it is suitable to print a paste of glass powder on the linear glass layer formation surface and bake it to form a glazed ceramic substrate having linear ridges. As the glass powder, for example, lead glass, borosilicate glass, etc. can be used, and a fire-resistant filler Pb is added to the glass powder.
OXMgO.

It is suitable to use it as a paste by adding BadSCaO or the like and adding α-terpine oats, ethyl cellulose or the like as a medium. This glass powder paste is applied to the entire surface of the linear glass layer forming surface using a printing machine, and then baked at a temperature of usually 600 to 1100°C using, for example, an electric furnace to form a glass film with a thickness of usually 5 to 50 μm. It is suitable for use with glazed ceramic substrates. This glazed ceramic substrate has a linear raised part whose shoulder part is a gently curved surface and whose top surface is flat, with the steep step difference between the ceramic substrate and the straight glass layer being alleviated by the firing. Be able to draw a line with high accuracy.

This glazed ceramic substrate is made by forming a heating resistor on its linear protuberance by means such as vapor deposition, sputtering, or photolithography, and then dividing this heating resistor into a number of parts and connecting electrodes to each of them. A head can be manufactured. This thermal head generates heat when energized, and can output a large number of pixels in a straight line onto, for example, heat-sensitive recording paper to print with uniform print density.

(e) Function: Patterned with photoresist and etched to form a straight glass layer, improving the straight line accuracy of this glass layer.Since a glass film is formed on top of this by firing, the surface of this glass film is The linear raised portion that is formed has no steep steps, has a gentle curve at the bottom and shoulder, and has a flat top surface with high linear accuracy.

(f) Example A second embodiment of the invention will be described with reference to the drawings.

First, as shown in Figure 2, the height is 80a+x and the width is 270.7
．． t.

High resistance ceramic substrate 1 (pure 119) with thickness Q and 8ztr
Glass powder paste (trade name 4608H manufactured by Electro Science Laboratory) was applied by a printing machine to the entire surface of the Al2tOi (0% or more Al2tOi), and heated to 930℃/5='+
A glass film 2 was formed by firing the glass film.

Next, this ceramic substrate was attached to a spinner, and a solvent solution of novolac resin-〇-quinonediazide-based positive photoresist was applied dropwise onto the glass film 2. After drying, it was irradiated with near ultraviolet rays of 300 Na+. It was made easily soluble, and the easily soluble portion was dissolved and developed with a phosphoric acid ester-based phenomenon liquid to form a predetermined pattern.

Next, as shown in FIG. 3, the glass film 2 is etched according to the pre-etched pattern using an HF-based aqueous solution, and the photoresist layer 3a is removed using an N-methyl-2-pyrrolidone-based stripping solution. 2 from the side edge of the board as shown in
．． A glass layer 2a having a length of 10 x m, a total length of 270 yr, and a thickness of 60 μm was formed at a position of 5 x z. This glass JiJ
2a had a high linear accuracy in the section direction within the range of ±IQam.

Next, an amorphous glass paste manufactured by DuPont under the trade name 8190 was stamped on the entire surface of the substrate on which the glass FJ2a was formed.
It was coated using a glass layer 2λ and baked at 1050°C/15NB to form a film with a thickness of 20μ on top of the glass layer 2λ as shown in Figure 1.
A glazed ceramic substrate on which a glass film 4 of m thickness was disposed was obtained. This glazed ceramic board has a width of 1.2xx and a length of 270xm at a position 2.5xa from the side edge of the board.
The shoulder portion with a height of 80 μm had a gently curved surface, and the upper surface had a flat raised portion with high linear accuracy.

Furthermore, as shown in FIGS. 5 and 6, a heating resistor layer 5 is formed by laminating a Ta-3ift heating element with a thickness of 2000 on the glazed ceramic substrate 1a by sputtering, and an aluminum layer with a thickness of 12 μm is further formed. A thermal head was fabricated by sequentially forming a common electrode layer 7 consisting of a lead 1i electrode film 6 made of an Af2-based alloy having a thickness of 8000, an insulation 1112, an abrasion-resistant protective film 8, and a solder resist layer 9.

Next, the obtained thermal head was attached to a thermal printer and a printing test was conducted. As a result, it was confirmed that the variation in print density was significantly improved compared to a thermal head fabricated using a conventional glazed ceramic substrate. In addition, the manufacturing process of the thermal head has good step coverage of the low heat generation antibody formed on the glazed ceramic substrate, and the coverage of the photoresist in the photolithography process has been improved, resulting in high productivity and is suitable for mass production of thermal heads. .

(G) Effects of the Invention According to the present invention, there is provided a method for manufacturing a glazed ceramic substrate having a linear protrusion with high linear accuracy, which has no steep steps, has a gently curved bottom and shoulder, and has a flat top surface. By using a glazed ceramic substrate manufactured by this manufacturing method, a thermal head with small variations in printing density can be manufactured with high productivity.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a glazed ceramic substrate produced in an example of the present invention, FIGS. 2 to 4 are explanatory diagrams of the manufacturing process of a glazed ceramic substrate of this invention, and FIGS. 5 and 6 are diagrams of the invention. FIG. 7 is an explanatory diagram of a conventional glazed ceramic substrate, and FIG. 8 is an explanatory diagram of the manufacturing process of a conventional glazed ceramic substrate. 7...Common electrode layer, 8...Wear-resistant protective film, 9...Solder resist layer, 0...Heating resistor part, 12... ...Insulating layer. 1.11...Ceramic substrate, la...
・Glazed ceramic substrate, 2.4.44...
・Glass film, 2a, 22...Glass layer, 3.31...Photoresist layer, 5...
Heat generating resistance layer, 6...Lead electrode film, Figure Figure Figure Figure Figure

Claims (1)

[Claims] 1. Print a glass powder paste on a ceramic substrate for a thermal head and bake it to form a glass film. Apply a photoresist on top of this and place it at a position corresponding to the heating resistor of the thermal head to be formed. The surface of the glass film is patterned leaving the photoresist, the glass film is etched according to this pattern to form a straight glass layer, and a paste of glass powder is printed on top of this and baked to form straight protuberances. A method for manufacturing a glazed ceramic substrate for a thermal head, characterized by forming a glazed ceramic substrate having a glazed ceramic substrate.