JPS61291153A - Thermal head - Google Patents

Abstract

PURPOSE:To smooth the surface configuration at the boundary part of partial glaze and to reduce the disconnection and short circuit of a conductor lead, by forming entire surface glaze to the surface of a substrate having partial glaze formed thereto. CONSTITUTION:Because entire surface glaze 3 is formed to the surfaces of a substrate 1 and partial glaze 2, the change in the surface configuration at the boundary part of the partial glaze 2 and the substrate 1 becomes smooth. The conductor lead 4 formed on said glaze 3 can be certainly formed without generating a flaw in the resist coating, exposure and development in a photolithography process and a pattern can be formed without generating an important flaw such as disconnection or short circuit. The entire surface glaze is formed of an electric insulating substance with a m.p. or softening point of 600 deg.C or more, for example, desirably formed of glass with a m.p. or softening point of 600 deg.C or more. Because a gold paste baked at 450-500 deg.C is used in the conductor connecting the conductor lead 4 and an external circuit, said insulating substance is used in order to prevent the melting or softening of the entire surface glaze 3 in the baking process of said lead 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in reducing pattern defects in one step of photolithography at a partial glaze boundary of a thermal head using a partly glazed substrate.

[Conventional technology]

Conventionally, there has been a thermal head of this type as shown in FIG.

In the figure, il+ is a substrate with a partial glaze (21) provided on a part of its surface. (4) is a conductor lead, (
5) is a heating resistor provided on the partial glaze (2) between the conductor leads, and (6) is a protective layer that completely protects the heating resistor (5) and the conductor leads (4) in the vicinity thereof.

Next, the effect will be explained. The heating resistor (6) formed on the partial glaze (2) formed on the substrate +11 is supplied with signals and power from the conductor lead (4a) to (4b) and generates heat. This heat is radiated through the entire protective layer (6) on the heating resistor (5) to the thermal paper, ink ribbon, etc. that is sandwiched between the protective layer (6) and the suppression roller (not shown). .

[Problem that the invention seeks to solve]

Conventional thermal heads are constructed as described above, so that the conductor lead that supplies signals and power to the heating resistor does not have a smooth change in surface shape at the boundary between the partial glazes on the substrate, but instead has a discontinuous surface shape. Therefore, there were disadvantages such as wire breakage, and short-circuiting of adjacent conductor leads because the resist application, exposure and development steps in the photolithography process were not reliably developed.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional method. By forming a full-surface glaze on the surface of a substrate on which a partial glaze has been formed, the surface shape at the boundary between the partial glazes becomes smooth. The object of the present invention is to provide a thermal head that can reduce disconnection and short circuits of conductor leads.

[Means for solving problems]

The thermal head of the present invention has a partial glaze formed on the substrate and a glaze formed over the entire surface of the substrate.

[Function] In the partially glazed L/- substrate of the present invention on which the entire surface is glazed, the surface shape changes smoothly at the boundary between the partial glazes, thereby preventing disconnection and shorting of conductor leads in one photolithography process. be able to.

[Embodiments of the invention]

Hereinafter, the present invention will be explained with reference to the embodiment of FIG. 1, in which the same reference numerals are given to the parts corresponding to the conventional Pl]. ,',((This is the entire glaze formed on the surface of glaze (2).

The configuration other than the above is the same as the conventional one, so a complete explanation thereof will be omitted.

In the thermal head of the present invention configured as described above, the entire surface of the glaze (3) is formed on the surfaces of the substrate (1) and the partial glaze (2), so that the boundary between the partial glaze (2) and the substrate il+ is The change in surface shape becomes smooth, and the conductor leads (4) formed on it can be coated with resist, exposed, and developed in the photolithography process without causing defects, resulting in serious defects such as disconnections and short circuits. The entire pattern can be formed without any problems.

The material for the entire surface glaze (3) is an electrical insulator whose melting point or softening point is above AOO'C, for example 600°C.
It is desirable that the glass be made of glass having a melting point or softening point higher than that. It uses gold paste fired at 450'C to 500'C for the conductor connecting between the conductor lead (4) and the external circuit, so the entire surface becomes glazed (3
) must not melt or soften.

In the above embodiment, the entire surface is glazed +31 and the i-substrate is +1.
1 and the partial glaze (2) are shown, but the glaze may be formed on the entire surface +31' and stopped at a position slightly overlapping the partial glaze (2).

Furthermore, in the above embodiment, the glaze (3) is formed on the entire surface of the substrate 11), but the glaze is not formed on the entire surface, except for areas where the glaze is unnecessary for pattern design and areas where the glaze is not needed for heat dissipation. It can be anything.

〔Effect of the invention〕

As described above, according to the present invention, since the entire surface glaze is formed on the entire surface of the partially glazed substrate, the change in the surface shape at the boundary between the substrate and the partially glazed layer becomes smooth, and defects in photophosphor layer printing are greatly reduced. As a result, it is possible to obtain a thermal head in which disconnection and short-circuiting of conductor leads are greatly reduced.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view showing a thermal head according to an embodiment of the present invention, and FIG. 2 is a cross-sectional side view showing a conventional thermal head. In the figure, (1) is the substrate, (21 is the partial glaze, (
3) is the entire surface glazed, (4) is the conductor lead, (5) is the heating resistor, and C6) is the protective layer. In addition, the same reference numerals in the figures are the same - or (・O indicates the target part.

Claims (3)

[Claims] (1) Corresponding to a partial glaze layer formed on a part of the substrate, this partial glaze layer and a second glaze layer formed on the substrate, and the partial glaze layer on this second glaze layer. A thermal head equipped with a conductor lead provided across a corresponding part and a non-corresponding part. (2) The thermal head according to claim 1, wherein the material of the second glaze layer is an electrical insulator and has a melting point or softening point of 600° C. or higher. (3) The thermal head according to claim 1, wherein the second glaze layer is made of glass having a melting point or softening point of 600° C. or higher.