JPS60206675A - Thermal printing head and manufacture thereof - Google Patents

Abstract

PURPOSE:To locate a heating element closely to an end edge of a substrate, by a method wherein the second electrode is made to be individual electrodes so that electric currents are selectively supplied therethrough, and heating elements for printing are provided on the surface of the first insulator layer so as to cross the first and second electrodes. CONSTITUTION:A common electrode 2 and a conductor part 2B are provided on the surface of the substrate 1 by screen printing, and branch electrodes 2C' are also provided. Next, insulator layers 4, 5 are provided by screen printing of a glaze. Thereafter, to provide electrodes 6, 7 and terminal electrodes 10, an electrode layer 12 is provided on the surface of the substrate 1 by screen printing or the like, and are etched in a desired pattern. Then, the heating elements 8 are provided on the surface of the insulator layer 5 so as to cross the electrodes 6, 7, or a driving circuit 9 is provided on the surface of the insulator layer 4. After connecting by wires 11, the assembly is covered by a protective film, an abrasion-resistant film or the like.

Description

Detailed Description of the Invention [8] This invention relates to a thermal print head and its manufacturing method.In this type of thermal print head, a heating element for one printing is placed as close as possible to one edge of one substrate. This is advantageous in that characters printed on thermal paper can be read immediately after printing. However, in a configuration in which current-carrying electrodes are installed across the width of the heating element, it is necessary to secure an installation area for the electrodes between one side edge of the heating element and one end edge of the substrate. Therefore, it has been considered impossible to bring the heating element close to one edge of the substrate due to this installation area.

To solve this problem, one electrode and the other electrode connected on both sides of the heating element are both extended toward the opposite edge of the board, and one electrode is connected to a common electrode, and the other electrode is connected to a common electrode. The electrode extends in a groove on the surface of an insulating layer formed on the surface of the common electrode, and the one electrode connected to the common electrode also extends to the surface of the insulating layer. was separately proposed by the present inventor. With this configuration, there is no need to install a wire between one side edge of the heating element and the edge of the board (because it becomes necessary to place the heating element sufficiently close to one edge of the board). It is now possible to install
However, it is extremely convenient that the heating element of this zelkova is required to be placed on the surface of the glaze layer in order to prevent the heat from being conducted to the substrate as much as possible. Therefore, in the previously proposed structure described above, a glaze layer is formed entirely on the surface of the substrate.
A heating element is formed on the surface of a portion thereof, that is, a portion close to one edge of the substrate. Therefore, this glaze layer and the glaze layers for the two aforementioned insulating layers had to be formed in separate steps. This has the disadvantage that not only the manufacturing process but also the configuration is extremely complicated due to the force exerted by the heat generating element. Since +y>4 according to Mu, it partly follows that meaning, and making 4# becomes troublesome.

The purpose of the invention is to simplify the configuration in order to bring the heating element sufficiently close to the edge of the substrate by not installing an electrode between the heating element and the edge of the substrate. do. Another object of the present invention is to facilitate the manufacture of the above structure.

Embodiments of the invention will be described with reference to the drawings. 1 is an insulating substrate such as amine ceramic.

In the present invention, a heating element for printing is to be installed close to one side of the insulation 1A of the substrate 1. A common electrode installed on the surface of two substrates 1 - one edge 2
A and the edge IA face each other with a space 8 interposed therebetween. 2B is a lead-out portion of the common ff (M, 2). 4 is an insulating layer that covers the surface of the common electrode 2, and is composed of, for example, a glaze layer as described later. 2 on the edge 2A side (yh at every constant pitch P - that edge 2
The common electrode 2 is covered so that A is exposed. Specifically, on the edge 2A of the common electrode 2, there is a branch electrode 2C for each pitch P.
(See 1 from Figure 2 onwards.)

This branch @1120 is left to cover the common electrode 2 with the insulating layer 4.

An insulating layer 5 is formed on the surface of the substrate l on the edge IA side by the same layer (glaze layer, etc.), and an electrode 6 is formed so as to extend from this insulating layer 5 to the surface of the insulating layer 4 via the space 8. .7 is formed.It serves as an electrode for 6 individual electrodes, and is placed between the poles 7 and sticks.
serves as a common electrode, and overlaps each branch M2C exposed from one insulating layer 5 in the cavity 8. Reference numeral 8 denotes a heating element for printing, which is formed on the surface of the insulating layer 5 so as to cross each electrode 6.7 in its width direction. Reference numeral 69 denotes a heating element 8, which is formed into a heating area 8A divided by each electrode 6.7. A drive circuit consisting of an integrated circuit or the like is installed on the surface of the insulating layer 4 for selectively energizing and generating heat. lO is a terminal electrode 11 that externally supplies a drive signal to the drive circuit 9;
is electrode 6. This is a wire such as a gold wire that connects the terminal electrode 10 and one drive circuit 9. Although not shown, protective ridges, wear-resistant ridges, etc. are formed on these surfaces as necessary.

With the above configuration, if one lead-out part 2B is connected to one terminal of the power source for heat generation, one end of all the heat-generating areas 8A is connected to one terminal of the power supply through the lead-out part 2B, the branch electrode 2C, and the electrode 7. It will be connected to the terminal. Therefore, by selectively using the electrode 7 as the other terminal of the power source in accordance with the output signal of the drive circuit 9, the heat generating region 8A will selectively generate heat. These operations are particularly different from those of this type of Therma-V printhead; however, as can be seen from the fcMP description above, in this configuration, the surface of the substrate 1 is uniformly glazed as previously proposed. Without forming a layer, the surface of the previously formed common electrode and the substrate l
An insulating layer 4.5 is provided on the edge IA side of the insulating layer 4.5. And since the installation of the common electrode layer is omitted, it is common! This simplifies the configuration for pole insulation. In other words, while the previously proposed configuration has a three-layer structure consisting of the lowermost glaze layer on the surface of the substrate l, one common electrode, and the glaze layer on the surface, in this invention, the lowermost glaze layer A two-layer structure can be used without the glaze layer. Having a two-layer structure like this-h! This was made possible by providing the insulating layer 5 with only the heating element 8, and as will be described later, if the glaze printing and firing were performed on the image insulating layer 4.5 at the same time. .

- It can be formed in just one process, making it easier to manufacture.

Next, the manufacturing method according to the present invention will be claimed by No. S+♂.

A common electrode 2 and a conductor portion 2B are formed on the surface of the substrate 1 by screen printing as shown in A of No. 8U.

At this time, branch electrodes 2C are also formed at the same time. However, as shown in the diagram, this branch electrode 2C is formed to have a width sufficiently wider than that of the electrode 7.
This is to facilitate the alignment of the mask during etching in step 7. 20' is a branch electrode 2C by etching.
This is the electrode part.

As described above, the edge 2A of the common electrode 2 is spaced apart from the edge HA of the substrate 1. In the previous proposal, the common electrode 2 was formed by etching. This is because in order to maintain the overlap with the market price 7, it was necessary to place electricity at the position of the overlap with high precision. However, as mentioned above, the width -W [portion 20'
If the common electrode 2 is used, the alignment becomes easy, and high precision at one position is not required.Therefore, the common electrode 2 is formed by low b screen printing with one position accuracy, rather than by etching. Next, the insulating layers 4 and 5 are formed as shown in FIG.
Both insulating layers 4.5 can be formed simultaneously by one screen printing and baking process.

Next, an etching process is performed for the electrodes 6, 7 and both terminal electrodes 1o. For this purpose, as shown in FIG. 3C, seven pupils N12 are formed on the surface of the substrate 1 by, for example, screen printing. This is then etched according to the required pattern. At this time, more than Wi7! Bar part QC'
Since it is considered to be wide and sticky, -W41? Since there is more leeway in positioning the mask for forming the mask, the position of the mask becomes easier. In addition, the W pole portion 9C protrudes from both sides 1 at the position where the electrode 7 is formed. By not applying resist to this protruding portion, it is simultaneously removed along with other portions by etching. As a result, the electrode 7 and the branch electrode 2C are formed to overlap each other so that their (l11 planes) are aligned.

After that, a heating element 8 is formed on the surface of the insulating layer 50 so as to cross 6.7 f of one electrode, or a driving circuit 9 is formed on the surface of the insulating layer 4.
Set up. After connecting with the wire 11, a protective film is formed.
Cover with wear-resistant film, etc.

When manufactured by this method, compared to the previously proposed structure, the insulating layer formation process is required only once, and the electrode formation process is also required only once. It becomes simpler.

As detailed above, according to the present invention, when the heating element is installed close to one edge of the board, the configuration for this purpose can be simplified compared to the previously proposed one, and the manufacturing thereof can be simplified. As for the process, if both the etching process and the insulating layer forming process can be reduced, it will be possible to simplify the process by that much, which will bring about a great effect.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 20 is a partially enlarged perspective view, and FIG. 8 is a v-plane view for explaining the manufacturing process of the present invention. l... Board, IA... Edge, 2...
・・Common electrode, 2A・・Edge, 2C・・・・
・Branch N pole, 4... Second insulating layer, 5...
...Second insulating layer, 6...Second W pole-7...
...First electrode, 8...Heating element-12...
...Engoku layer helmet/diagram

Claims (2)

[Claims] (1) A first insulating Mf made of glaze is provided on the surface of an insulating substrate along one edge thereof, and a common electrode is provided at a position apart from the first insulating layer. A second insulating layer is provided on the surface of the common electrode at a predetermined interval along an edge of the common electrode on the side of the first insulating layer, and is a part of the common electrode. Further, a plurality of first and second electrodes each having a length of one hour on the surfaces of both the first and second insulating layers are arranged in alternating rows along one edge of the substrate. An electrode is connected to the common electrode by engaging the branch electrode, and the second electrode can be selectively energized as an individual electrode. A thermal print in which a heating element for printing is provided across the second electrode. (2) A first step of forming a common electrode on the surface of an insulating substrate by screen printing so as to be spaced from one edge of the substrate, and one edge of the substrate. and a first insulating layer along the surface of the common electrode, and a predetermined interval W7I on one edge side of the common electrode.
A second step of simultaneously forming a second insulating layer by printing and baking a single glaze so as to expose a branched electrode cable wider than the electrode for current-carrying; Eighth step of forming the entire electrode layer in the region including the formation position
(a) forming first electrodes and second electrodes on the surfaces of the first insulating layer and the second insulating layer so as to be alternately located along one edge of the substrate; At the same time, a fourth step of etching the electrode layer so that the branch electrode that is in electrical contact with the first wl electrode has the same width as the first electrode; , a fifth step of forming a heating element for printing across the first and second electrodes,