JPS5863478A - Manufacture of thermal head - Google Patents

Abstract

PURPOSE:To obtain a thermal head with a better contacting property of a heat sensitive paper by a method wherein belt-shaped and dot-shaped projections are formed on a substrate surface made of ceramics or glass by etching and wire sections made on the plane section flush with the projection formed surface on the substrate after the formation of a resistance heat generating body on the projections. CONSTITUTION:For example, a required pattern is formed of hydrofluoric acid resistant material on an alumina substrate 1 to be left as a projection 2. Then, it is etched with a hydrofluoric acid-based etching liquid to form belt-shaped (or dot-shaped) projections 2, on which a resistance heat generating body 3 made of an NiCr based resistance thin film is formed by photoetching/printing or the like. Wire sections 4a and 4b connected to the heat generating body 3 are formed on the plane section of the substrate 1. If necessary, the heat generating body 3 and the wire sections 4a and 4b are covered with a protective film 7 made of SiC or the like. EFFECT:The new invention facilitates the production of the resistance heat generating body and the wire sections to prepare while simplifying the connection of the terminal leader. Further miniaturization is also possible.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a thermal head.

What has been put into practical use as a conventional thermal head,
Some have several resistance heating elements provided on the surface of the cylinder except for the end faces. This thermal head has good contact properties and high resolution because the thermal paper comes into contact with a part of the cylindrical surface. Further, it has advantages such as easy configuration of the wiring section and easy connection of lead wires. However, since it has a cylindrical shape, it is often difficult to create resistance heating element stripes due to poor contact with a photomask, and it is also difficult to create heating element stripes by printing or the like. Furthermore, since it is cylindrical, it has a large volume.

One thermal head that has been put into practical use is one in which a resistance heating element is provided on a substrate. Since this thermal head is flat, it is easy to use photomasks and print.
Both the so-called thick film method and thin film method can be easily performed. Furthermore, it has the advantage of being small in volume. However, on the other hand, since it is in the form of a substrate, it is not possible to specify the surface in contact with the thermal paper, and there may be cases where the thermal paper and the heating element do not come into close contact with each other. In this case, the resolution naturally decreases, and if the wiring part is on the same surface as the heating element, parts other than the heating element will act on the thermal paper and affect it, so the wiring part needs to be placed away from the heating element. This makes the structure complicated, as it requires drilling a hole in the board and passing a conductive part through it in order to connect it to the wiring part provided on the back side. In addition, since the lead wire connection portion is naturally raised above the plane, it would be inconvenient if it were on the same plane as the heating element, and it is necessary to separate it from the heating element like the wiring portion. The simplest method is to provide a wiring section and a lead wire connection section on the back surface of the board, but as mentioned above, there are difficulties in connecting the front surface where the heating element is located and the back surface.

In view of the above points, it is an object of the present invention to facilitate the production of a resistance heating element and a wiring section, to facilitate the connection of terminal draw-out sections (lead wires), to facilitate manufacturing, and in particular to provide good contact with thermal paper. It is an object of the present invention to provide a method for manufacturing a thermal head that can improve resolution and achieve miniaturization.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a top view of a thermal head manufactured by an embodiment of the method of the present invention, and FIG. 2 is a front view thereof. In the figure, reference numeral 1 denotes an alumina substrate having a thickness of one line, and on this alumina substrate 1, a required pattern to be left as a protrusion 2 is formed using a hydrofluoric acid-resistant material. Next, it was etched with an etching solution containing fluoric acid as a main component to form a band-shaped protrusion 2. The width of this protrusion 2 is 350μm at the top and 6mm at the bottom.
00 μm, and the height of the protrusion 2 is 5077 m.

A 300 lt m square resistance heating element 3 is placed on top of this protrusion 2.
7 dots are formed by a method such as photo-etching or printing, and a wiring portion 4a connected to this resistance heating element 3 is formed.
, 4b are formed on the flat portion 5 of the alumina substrate 1. 4
a is a common electrode commonly connected to the resistance heating element 3;
4b is an individual electrode connected to each resistance heating element 3 individually. Further, 6 is a wiring section 4a.

This is the lead wire connection part that is fully connected to 4b. Resistance heating element 3
is a resistance loop wire whose main component is NiCr, and the wiring portions 4a, , ab and the lead wire connection portion 6 are conductor films whose main component is Cu. In addition, the resistance heating element 3 and the wiring part 4a
, ab are covered with a protective film made of SiC or the like, as shown in FIG.

In the above embodiment, an alumina substrate is used as the substrate, but porcelain such as forsterite and mullite, glass such as borosilicate glass, quartz, and ordinary glass may also be used. Even in such a case, the protrusion can be formed by etching in the same manner as in the above embodiment.

Further, although the shape of the protrusion is band-like in the above embodiment, it is natural that it may be a dot-like protrusion or may have a different size.

In addition, the resistance heating element is made of a material other than NiCr, such as Ta.
.

Ru 20 and the like can also be used, and alloys of NiCr and other metals can also be used.

As described above, in the manufacturing method of the present invention, protrusions are formed in the form of strips or dots on one surface of a porcelain or glass substrate using an etching jig, and resistive heating elements divided into required patterns are formed on these protrusions. It is easy to form odor protrusions on the insulating substrate for the wiring connected to the resistance heating element, and the positioning of the resistance heating element and the wiring is also easy and precise.
It can be formed into a large size, has good contact with thermal paper, and can produce a high resolution thermal paper.

[Brief explanation of the drawing]

FIG. 1 is a top view of a thermal head manufactured by an embodiment of the method of the present invention, FIG. 2 is a front view of the same, and FIG. 3 is a sectional view taken along line AA' in FIG. 1...Alumina substrate, 2...Protrusion,
3... Heating resistor, aa, ab...
Wiring section, 6... Planar section of the board.

Claims (1)

[Claims] A band-shaped or dot-shaped protrusion is formed on one surface of a porcelain or glass substrate by machining/v-etching, a resistive heating element divided into a required pattern is formed on this protruding part, and a wiring section is connected to this resistive heating element. A method for manufacturing a thermal head, in which the thermal head is formed on a flat surface of the insulating substrate on the same surface as the surface on which the protrusion is provided.