JPS62170361A - Thermal head and manufacture thereof - Google Patents

Abstract

PURPOSE:To ensure favorable contact of a thermal head with a printing paper and enable the head to print with high quality irrespective of the smoothness of the paper, by providing a heat generating region for printing in a protuberant form. CONSTITUTION:A glaze layer 11 substantially semi-circular in vertical cross-sectional shape and substantially belt-like in plan view is provided on one side of an insulating substrate 10 consisting of a ceramic or the like. A plurality of substantially semi- spherical projected regions 12 are provided at an upper part of the glaze layer 11. In a direction orthogonal to the longitudinal direction of the glaze layer 11, a plurality of heat generating layers 13 in a strip form in plan view are provided in parallel at regular intervals and astride the glaze layer 11, corresponding to the number of the projected regions 12. The layers 13 cover top parts of the projected regions 12, and the heat generating layer 13 on the projected region 12 is called a heat generating region 13a. The surface of the layer 13 exclusive of the heat generating region 13a is covered by a conductive layer 14 formed of, for example, gold or aluminum, whereas the heat generating region 13a is left exposed. Surfaces of the layers are covered by a protective layer 15, which is also protuberant on the projected regions 12.

Description

Detailed Description of the Invention The present invention provides a thermal head and a thermal head improved so that the heat generating area of the heat generating layer easily contacts the printing paper regardless of the smoothness of the printing paper. It relates to its manufacturing method.

A conventional general thermal head is shown in FIGS. 5 and 6, and will be described with reference to the same figures.

In these figures, reference numeral 1 denotes an insulating substrate made of, for example, ceramic. A glaze layer 2 is formed on one surface of the insulating substrate 1. The glaze layer 2 has a substantially semicircular arc shape in longitudinal section and a substantially band shape in plan view. In a direction perpendicular to the longitudinal direction of the glaze layer 2, band-shaped heat generating layers 3 are formed in parallel with each other at regular intervals so as to straddle the glaze layer 2, corresponding to the number of printed dots.

On the surface of the heat generating layer 3, there is a heat generating area 3 at the top of the glaze layer 2.
A conductor layer 4 is applied so that a is formed. Because of this conductor layer 4, the heat generating area 3a is in a depressed state. It should be noted that each of the above layers is covered with a protective layer M5 except for a part, and the protective layer 5 above the heat generating area 3a is also in a recessed state (see FIG. 6).

■ tries to make 7'. (2) When printing, it is common to press thermal paper, which is printing paper, against the recessed heating area 3a with a platen roller having a circular or flat cross section.

However, in a thermal head that uses the heat generating area 3a in the recessed state, if printing paper with low smoothness, that is, relatively rough, is used, the contact state of the printing paper with the heat generating area 3a tends to be incomplete. Heat conduction to some thermal papers is impaired, forcing a reduction in print density. For these reasons, conventional thermal heads have had to use highly smooth printing paper.

The present invention has been made in view of the above-mentioned circumstances, and provides a thermal head and a thermal head capable of realizing high-quality printing by ensuring good contact between the heat-generating area of the heat-generating layer and the printing paper even when printing paper with low smoothness is used. The purpose is to provide a manufacturing method.

. The thermal head according to the first invention for reading fortune-telling has a raised heat-generating area that is brought into contact with printing paper. That is, such a thermal head includes a glaze layer having a plurality of convex regions formed thereon, and a heat generating layer formed across the glaze layer so as to cover the top surface of the convex regions.

A method for manufacturing a thermal head according to a second invention includes forming a glaze layer having a predetermined transition point on an insulating substrate;
After forming a plurality of convex regions having a transition point lower than that of the glaze layer on the glaze layer, a heat generating layer is formed to cover the top surface of each convex region and to straddle the glaze layer. It is something that makes you

Since the convex areas on the plate glaze layer are in a raised state, the printing paper can easily come into contact with the heat generating layer on the convex areas.

11. In FIGS. 1 and 2, the reference numeral 10 indicates an insulating substrate made of ceramic or the like, and a glaze having a substantially semicircular arc shape in longitudinal section and a substantially band shape in plan view is provided on the - side.
is formed. A plurality of substantially hemispherical convex regions 12 are formed on the top of the glaze layer 11 . The number of convex regions 12 is formed in accordance with, for example, the number of printed dots of the thermal head itself. For reference, this convex region 12 has a diameter of, for example, 0.3 mm, and is approximately 0.1 mm in diameter.
It is assumed that they are formed at intervals of 5 mm.

In a direction perpendicular to the longitudinal direction of the glaze layer 11, heat-generating layers 13 each having a generally band-like shape in plan view are formed in parallel with each other at regular intervals so as to straddle the glaze 111, corresponding to the number of convex regions 12. . The heat generating layer 13 covers the top surface of the convex region 12, and the heat generating layer 13 on the convex region 12 is referred to as a heat generating region 13a. This heating area 1
The surface of the heat generating layer 13 except for the heat generating layer 13 is covered with a conductive layer 14 made of, for example, gold or aluminum, and the heat generating region 13a is exposed. The surface of each layer as described above is covered with a protective layer 15.
It is also raised above the convex region 12 (see FIG. 2).

When printing even with such a thermal head, as is well known, a plantain roller (not shown) with a circular or flat cross section is used to move the printing paper (not shown) to the heat generating area 13.
An operation of pressing the button a is performed. Since the heat generating area 13a is raised upward, the printing paper can easily come into contact with the heat generating area 13a through the protective film 15.

In addition, in the thermal head having the above configuration, the convex region 1
Although 2 has a substantially hemispherical shape, the present invention is not limited to this, and may be, for example, substantially trapezoidal. Also,
Although the convex regions 12 are separated from each other at regular intervals, the intervals may be set arbitrarily, and in order to increase the number of printed dots, the glaze layers 11 may be arranged in two parallel rows. , the convex regions 12 may be alternately arranged.

Next, an example of a method for manufacturing the thermal head having the above structure will be described with reference to FIGS. 3 and 4.

■ A paste having a transition point of about 800° C. is applied in a band shape by screen printing, for example, on the surface of the insulating substrate 10,
Through the firing process, a glaze layer 11 having a substantially semicircular arc shape in longitudinal section is obtained (see FIG. 3 (al)). Depending on where on the insulating substrate 10 this glaze layer 11 is formed, it can be, for example, an edge type or a center type. It is classified as a thermal head.

(2) Apply a paste having a transition point of about 600'C on the upper part of the glaze layer 11 at regular intervals in the longitudinal direction by, for example, screen printing, and go through a baking process to obtain approximately hemispherical convex regions 12 ( Figures 3(b) and 4(a)
(see l). In order to form this convex region 12, it is important to make the transition point of the paste that is the material of the glaze layer 11 higher than the transition point of the paste that is the material of the convex region 12.

(2) Forming a resistor film of tantalum nitride or the like by sputtering, for example, so as to cover the top surface of the convex region 12 and straddle the glaze layer 11 in a direction perpendicular to its longitudinal direction;
A heat generating layer 13 having a substantially band-like shape in plan view is obtained (see FIG. 3(C) and FIG. 4(b)).

■ Heat generating layer 13 excluding heat generating area 13a on convex region 12
A conductor layer 14 is deposited on the surface of the conductive layer 14, for example by lithography and vapor deposition (see FIG. 3(d)).

(2) After this, a protective JW 15 such as glass is applied so as to cover each of the above layers except for a part thereof (see FIG. 2).

Note that the method for manufacturing such a thermal head is not limited to the above embodiment. For example, the glaze fill can be formed by an etching process using lithography technology. Further, the convex region 12 can be applied using a dispenser or the like, and it is also possible to use a material such as aluminum, form an insulating film thereon, and then form the heat generating layer 13 and the like. Furthermore, the heat generating layer 13 and the conductor Fi14 can also be formed by thick film printing technology.

According to the thermal head of the present invention, the heat-generating region of the heat-generating layer is raised by the convex region, so that the contact state of the heat-generating region with the printing paper is good during printing. In other words, even if relatively rough printing paper with low smoothness is used, the raised heat generating area follows and efficiently contacts the roughness, resulting in improved heat conduction during printing. Therefore, the thermal head of the present invention can achieve high quality printing regardless of the smoothness of the printing paper.

[Brief explanation of drawings]

FIG. 1 is a plan view of a thermal head according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line A-A in FIG. 1, and FIG.
(dl is a process cross-sectional view for explaining an example of the manufacturing method of the thermal head, and FIGS. 4(a) and ('b) are 3rd
Figures (b) and (C) are side views, Figure 5 is a perspective view of a conventional thermal head, and Figure 6 is a longitudinal sectional view of the main parts of the thermal head. 10... Insulating substrate 11... Glaze layer 12... Convex region 13... Heat generating layer 13a... Heat generating region. Patent Applicant: ROHM Co., Ltd. Agent, Patent Attorney: Takaharu Ohnishi Figure 1 Figure 2

Claims (2)

[Claims] (1) a glaze layer with a plurality of convex regions formed on the top;
A thermal head comprising: a heat generating layer formed across the glaze layer so as to cover the top surface of the convex region. (2) After forming a glaze layer having a predetermined transition point on an insulating substrate, and forming a plurality of convex regions having a transition point lower than the transition point of this glaze layer on the glaze layer,
A method for manufacturing a thermal head, characterized in that a heat generating layer is formed to cover the top surface of each convex region and to straddle the glaze layer.