JPH0647939A - Manufacture of base for thermal head - Google Patents

Abstract

PURPOSE:To make into a glass glazed layer which is superior in insulation and heat insulation properties and has high regnerative effect, by a method wherein after formation of a projected line on the glass glazed layer so that a ratio W/H between a width W and height H is within a range of at least 1 and at most 10, the same is heat-treated at a temperature wherein viscosity of glass becomes 10<5> to 10<7> poises. CONSTITUTION:A glass glazed layer 12 having a smooth surface is formed on the whole or a part of one surface or both the surfaces of a ceramic base 11. A projected line 13 is formed partly on this smooth glass glazed layer 12 by dry or wet etching or grinding such as plain grinding in succession. When the projected line 13 is formed partly, it is necessary that a thickness of the glass glazed layer 12 to be removed is made thinner than the thickness of the glass glazed layer 12 formed on the ceramic base 11. When a width of the projected line 13 is W and a height is H, W/H of the projected line 13 is made 0.1-10. Furthermore, the projected line 13 formed partly is heat-treated at the glass softening point or higher and viscoisty of glass within a range of 10<5> to 10<7> poises and the rectangular projected line 13 is made to have roundness on the same.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a substrate for a thermal head of a thermal transfer printer in which a glaze layer is formed on all or part of one side or both sides of a ceramic substrate. More specifically, the present invention relates to a method of manufacturing a thermal head substrate when forming a ridge having a W / H of 0.1 to 10 on the glaze layer.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for improving the printing quality and increasing the printing speed of thermal transfer printers. In order to meet this requirement, in a thermal head substrate used in a thermal transfer printer, it is essential that the surface of the glaze layer formed on the surface of the substrate is smooth and has no waviness or defects. It is necessary to increase the contact with the thermal paper. For this reason, the heating resistor forming portion of the glaze layer is formed into a convex strip having a curved surface. As a method for forming such a ridged glaze layer, a glass paste is printed and baked on the entire surface of the ceramic substrate, and then a similar glass paste is further printed and baked on a portion on which a ridge is required. There is an indirect method of forming ridges on the entire glaze layer. As another method, two kinds of glass pastes having different softening points are used. First, a glass paste having a high softening point is printed on a portion of the ceramic substrate other than the ridge forming portion and baked, and then the ridge forming portion. There is a direct method in which a glass paste having a low softening point is printed so as to have a desired height and fired to form a ridge in the entire glaze layer.

[0003]

However, in the above indirect method, since the glass flow on the ceramic substrate is small, the curvature of the ridge can be made relatively small, but the undulation near the top of the ridge is large or the ceramic substrate is large. On the other hand, there is a problem that fine wiring of conductors is required. On the other hand, in the above-mentioned direct method, conductor wiring can be formed on the surface of a smooth glaze layer, so that there are few problems such as disconnection, but on the other hand, it is usually smooth. At the glaze firing temperature for obtaining the surface of the glaze layer, the glass viscosity is as low as less than 10 ⁴ poise, so that the glass with convex stripes on the flat glass is easy to flow and has a radius of curvature of 15 mm.
There was a drawback that it was difficult to make it smaller than mm. In addition, there is an increasing demand for high-definition printing and color printing. To meet this demand, a ridge with a small radius of curvature of preferably 5 mm or less is formed on the surface of a smooth glaze layer. In addition, this ridge must have a waviness in the vicinity of its top of 1 μm or less. However, it is the current situation that the above-described method of manufacturing a substrate for a thermal head cannot cope with the situation. An object of the present invention is to provide a method of manufacturing a substrate for a thermal head, in which a ridge having a W / H of 0.1 to 10 has a radius of curvature of 1 mm or less. Another object of the present invention is to provide a method for manufacturing a substrate for a thermal head, in which the waviness in the vicinity of the top of the ridge is 1 μm or less, and the fine wiring of the conductor on the ceramic substrate is unnecessary.

[0004]

As shown in FIG. 1, according to the present invention, a glass glaze layer 12 having a smooth surface is formed on all or part of one side or both sides of a ceramic substrate 11, and a part of the glass glaze layer 12 is formed. To remove the glass glaze layer on the other part, and leave the remaining part on the ridge 1.
No. 3, and the glass glaze layer 12 is heat-treated at a temperature equal to or higher than the softening point of the glass to process the vicinity of the top of the ridge 13 into a curved surface. The characteristic structure is that the ridges are formed such that the width thereof is W and the height thereof is H, and 0.1 <W / H <10, and the viscosity of the glass softened by the heat treatment is 10 ⁵ to 1
It is to be performed at a temperature of 0 ⁷ poise.

The glass powder as a raw material for the glass glaze layer formed on one side or both sides of the ceramic substrate of the present invention satisfies both the insulation and heat resistance required for a thermal head used in a thermal transfer printer. Is. For example, as the main components of this glass powder, Si, C
a, Ba, Al, there are B, also Al ₂ O ₃ -BaO-B
_{A 2} O ₃ —CaO—SiO ₂ -based glass glaze layer is formed. As shown in FIG. 1 (a), a glass paste composed of glass powder and a binder is adhered on the ceramic substrate 11 by screen printing or spraying and fired to obtain a glass glaze layer 12 having a smooth surface. Subsequently, as shown in FIG. 1B, convex ridges 13 are partially formed on the smooth glass glaze layer 12 by dry or wet etching, polishing such as surface grinding, or the like. Glass glaze layer 1 to be removed by etching, polishing, etc. when partially forming ridges 13
The thickness of 2 must be smaller than the thickness of the glass glaze layer 12 initially formed on the ceramic substrate 11. In particular, the present invention is a manufacturing method in the case where the width W of the ridge is W and the height is H, and the W / H of the ridge 13 is formed to be 0.1 or more and 10 or less.

Further, the ridges 13 partially formed as shown in FIG. 1 (c) are heat-treated at a temperature equal to or higher than the softening point of the glass and a viscosity of the glass in the range of 10 ⁵ to 10 ⁷ poises. Then, the rectangular ridges 13 shown in FIG. 1 (b) are rounded. The characteristic point of the present invention lies in this heat treatment. Specifically, it is performed under the following conditions. The heat treatment is performed at a temperature at which the softened glass has a viscosity of 10 ⁵ to 10 ⁷ poise. At a temperature at which the viscosity of the glass becomes less than 10 ⁵ poises, the radius of curvature of the ridges after heat treatment exceeds 1 mm, while at a temperature above 10 ⁷ poise, the tops of the ridges after heat treatment are not completely curved. It is not preferable because a flat part remains.

[0007]

In order to round the convex stripes 13 of the glass glaze layer 12, W (width) and H of the glass glaze layer 12 are used.
After forming the ridges so that the ratio (height) W / H falls within the range of 0.1 or more and 10 or less, the viscosity of the glass is 10 ⁵ to 10 ⁷
When heat-treated in the range of poise, the radius of curvature of the ridge is 1m
It can be processed in a range of m or less.

[0008]

The present invention will be described in detail below with reference to examples. The invention is not limited by this example. A ceramic substrate 11 having a length of 270 mm, a width of 50 mm and a thickness of 1 mm and an alumina content of 96% was prepared. Glass powder with a softening point of 855 ° C. on the surface of this substrate (trade name:
ASF1760, manufactured by Asahi Glass Co., Ltd.), a glass paste obtained by mixing ethyl cellulose and terpineol was screen-printed to form a glass glaze layer 12, and the glass glaze layer 12 was dried at 150 ° C.
It was baked at 50 ° C. for 30 minutes. The thickness of the glass paste is
It was adjusted to be 60 μm after firing (FIG. 1 (a)).
W (width) is 0.
1 mm, 0.18 mm, and 0.25 mm with a length of 2
A thermosetting resist is printed on a screen having a pattern of 70 mm to form an etching resist film, and a portion not coated with the etching resist is etched with hydrofluoric acid to a depth of 0.03 mm, thereby forming 3
The ridges 13 having different widths were formed (FIG. 1 (b)). Further, heat treatment was performed under the nine conditions shown in Table 1 to make the ridges 13 round (FIG. 1 (c)). W / H of 3 types of convex parts
Were 3.3, 6.0, and 8.3, respectively. A rectangular glaze substrate formed by etching and having partially convex ridges was used, and the maximum temperature was 900 ° C, 950 ° C, 100 ° C.
The heat treatment was performed at 0 ° C. for 15 minutes each at the maximum temperature. Here, in the heat treatment, firing conditions such as a heating rate, a firing time, a holding time at the maximum temperature, a cooling rate, and a cooling time were obtained in advance by a preliminary test, and 60 of the firing furnace among the profiles of the firing conditions stored in the storage device was obtained. Based on minute profile. The viscosity of the glass at the highest temperature heat treatment from a conversion table, was 900 ° C. In 10 ^6.8 poise, at 950 ° C. 10 ^6.0 poise, and 1000 ° C. At 10 ^5.2 poise. When the surface of the glass glaze layer 12 after the heat treatment was observed, it was very smooth and defect-free. In addition, the ridge 13
Was curved and rounded. Further, the radius of curvature of the roundness and the waviness in the longitudinal direction were measured. The results are shown in Table 1.

[0009]

[Table 1]

From the results shown in Table 1, the W / H before heat treatment was 3.
When the heat treatment temperature is set to 3 to 8.3 and the glass viscosity falls within a specific range, the ridge radius of curvature after heat treatment is 0.1 to 0.9, and the waviness of the top of the ridge is increased. It can be seen that all are 0.2 μm or less.

[0011]

As described above, according to the present invention, the heat treatment after forming the ridge having W / H of 0.1 to 10 on the glass glaze layer is performed under a specific temperature condition. The waviness of the glass glaze layer on the top of the ridge is 1 μm or less,
A glass glaze layer having no unevenness and a smooth surface, and a glass glaze layer having a curved surface with a ridge having a radius of curvature of 1 mm or less are obtained, so that the glass glaze is excellent in insulation and heat insulation and has a large heat storage effect. A substrate for a thermal head having a layer can be manufactured. Further, when the heating resistor layer is formed on the ridges, it is possible to obtain a thermal head which does not require fine wiring of conductive wires and has a small variation in resistance value.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a thermal head substrate showing steps of manufacturing the thermal head substrate of the present invention.

[Explanation of symbols]

 11 ceramic substrate 12 glass glaze layer 13 ridge

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuru Suda 2270, Yokoze, Yokose-cho, Chichibu-gun, Saitama Sanritsu Materials Co., Ltd. Ceramics Laboratory (72) Hiroshi Ishii 2270, Yokose, Yokose-cho, Chichibu-gun, Saitama Sanryo Materials Co., Ltd. Ceramics Laboratory

Claims (1)

[Claims] 1. A glass glaze layer (12) having a smooth surface is formed on the whole surface or a part of one surface or both surfaces of a ceramic substrate (11), and a part of the glass glaze layer (12) is left and the glass of the other part is formed. The remaining part is formed on the ridge (13) by removing the glaze layer, and the glass glaze layer (1
In the method for manufacturing a thermal head substrate in which 2) is heat-treated at a temperature equal to or higher than the softening point of the glass to process the vicinity of the top of the ridge (13) into a curved surface, the ridge has a width W, When the height is H, it is formed so as to satisfy 0.1 <W / H <10, and the heat treatment is performed at a temperature at which the viscosity of the softened glass becomes 10 ⁵ to 10 ⁷ poise. A method for manufacturing a head substrate.