JPH03234672A - Thermal head - Google Patents

Abstract

PURPOSE:To improve the thermal efficiency and at the same time, improve the high speed thermal response property by a method wherein on a heating resistance body layer, an insulator layer or which slits are respectively formed on each individual electrode is formed, and on this insulator layer and in each slit, a plurality of individual lead wires to correspond with respective individual electrodes are formed. CONSTITUTION:On a glaze layer 2 and each electrode 4 which are provided on a base with insulating property 1, a heating resistance body layer which constitutes a heating resistance body 3 and an insulator layer 14 are laminated to form a thermal head, and after performing heat treatment by heating this thermal head in an oven, the thermal head is taken out of the oven. Then, by etching the insulator layers 14 which are directly above individual electrodes 46, a plurality of slits 14A are formed, and the heating resistance body 3 is exposed, and at the same time, the insulator layer 14 above the outer connecting terminal for a common electrode 4a is removed. Then, on the insulator layer 14, an electrode layer which consists of high melting point metals, W, Mo, Ti, Cr, etc., and an electrode layer which consists of Al, Cu, Au, etc., are laminated in order. When these electrode layers are etched, a plurality of individual lead wires 15 are formed with intervals between them. Each individual lead wire 15 is directly connected to the heating resistance body 3, and indirectly connected to each individual electrode 4b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal head that is installed in a thermal printer and performs desired printing by applying electricity and heating according to printing information, and particularly relates to improving its thermal efficiency.

[Conventional technology]

In general, a thermal head installed in a thermal printer such as a thermal printer or a thermal transfer printer has, for example, a plurality of heating resistors arranged in a straight line on an insulating substrate, and selectively selects each of the heating resistors according to printed information. In a thermal printer, the ink is heated and energized to record color on the thermal recording paper, and in a thermal transfer printer, the ink on the ink ribbon is melted and transferred and recorded on the paper.

FIG. 7 shows one side of a conventional thermal head of this type. On the upper surface of an insulating substrate 1 made of alumina or the like, a glaze layer 2 made of glass that functions as a heat storage layer is arranged so that the upper surface has an arcuate cross section. From the upper surface of the glaze layer 2 to the upper surface of the insulating substrate 1, a plurality of heating resistors 3 made of Ta2N etc. are laminated as a whole by vapor deposition, sputtering, etc. Later, by performing etching using photolithography, they are formed in linear alignment. A common electrode 4a and individual electrodes 4b for supplying current to each heating resistor 3 are formed on the upper surfaces of both sides of each heating resistor 3, respectively. Each of these electrodes 4a, 4b is, for example, AN
, Cu, AL1, etc., and is formed into a pattern of a desired shape by laminating the entire layer to a thickness of approximately 2 μm by vapor deposition, sputtering, etc., and then performing etching using photolithography technology. Each of the heating resistors 3 is formed independently between the common electrode 4a and the individual electrodes 4b so as to expose a heating dot 3A corresponding to one dot, which is the minimum printing unit,
The heating dots 3A of the heating resistor 3 are connected to each of the electrodes 48.
．． Heat is generated by applying a voltage across 4b.

On the upper surface of the insulating substrate 1, glaze layer 2, each heating resistor 3, and each electrode 4a, 4b, a protection film 115 with a thickness of approximately 7 to 10 μm is provided to protect each heating resistor 3 and electrodes 4a, 4b. This protection 1t5 includes an oxidation-resistant layer 6 made of SiO2 or the like having a thickness of approximately 2 μm and protecting the heat-generating resistor 3 from deterioration due to oxidation, and a thermal recording paper laminated on the oxidation layer. Each heating resistor 3 and electrode 4a are protected from wear due to contact with a heat-sensitive recording member such as an ink ribbon.

4b, and a wear-resistant layer 7 made of Ta205 or the like and having a film thickness of approximately 5 to 8 μm, and this protection I!
25 covers the entire surface of each electrode 4a, 4b other than the terminal portion.

The oxidation-resistant layer 6 and the wear-resistant layer 7 of the protective layer 5 are sequentially formed by means such as sputtering.

Note that in actual manufacturing of thermal heads, multiple thermal heads are formed on one insulating substrate 1, so in the final process, the insulating substrate 1 is divided into a predetermined number of thermal heads. Now you get a head chip.

In the thermal transfer printer using the conventional thermal head described above, the thermal head is brought into pressure contact with the paper via the ink ribbon, and the individual electrodes 4b corresponding to the desired dots are energized based on predetermined print information.
By causing the heating resistor layer 3 to generate heat and melting and transferring the ink of the ink ribbon onto the paper, desired printing can be performed on the paper.

FIG. 8 shows the other side of a conventional thermal head of this type, and the shape of the glaze layer 2 is different from that shown in FIG. 7 described above.

That is, the glaze layer 2 in FIG. 7 is partially formed on the insulating substrate 1 so that the top surface has an arc-shaped cross section, whereas the glaze layer 2 in FIG. 8 is formed so that the top surface is flat. It is formed over the entire predetermined range of the insulating substrate 1-[. Therefore, the upper surface of the one shown in FIG. 8 is closer to a flat surface than that of FIG. 7. In addition, the other configurations are as follows.
It is similar to the figure.

(Problems to be Solved by the Invention) However, in the conventional thermal head described above, approximately 40% of the heat generated by energization in the heat generating resistor 3 is transmitted toward the glaze layer 2 and is lost. , approximately 4 in the direction of each electrode 4a, 4b.
Since 0% of the heat is transferred and lost, only 20% of the heat is effectively utilized as printing energy. Therefore, there is a problem in that thermal efficiency is significantly reduced, printing energy density cannot be maintained high, and large energy loss occurs.

Furthermore, if the thickness of the glaze layer 2 is made large in order to improve thermal efficiency, the heat capacity of the glaze layer 2 increases and the amount of heat storage increases, making it possible to obtain the high-speed thermal response necessary for high-speed printing. The problem is that it disappears.

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermal head capable of solving the above-described problems in the conventional head, improving thermal efficiency, and increasing high-speed thermal response.

[Means to solve the problem]

In order to achieve the above-mentioned object, the thermal head of claim 1 forms a glaze layer on an insulating substrate, and selectively energizes a plurality of heating resistors and each heating resistor on this glaze layer. In a thermal head in which a plurality of electrodes are laminated in an aligned manner to form heating dots on each heating resistor, and the upper part of these is covered with a protective layer, a large number of electrodes are formed on one side of the base on the glaze layer. A common electrode formed by protruding strips in parallel, and a large number of individual electrodes arranged at intervals between a pair of adjacent strips, and these glaze layers and the common electrode. A heating resistor layer is formed on each individual electrode so that a heating dot is formed between a pair of adjacent strips of the common electrode, and each of the above-mentioned separate electrodes is formed on this heating resistor layer. The present invention is characterized in that an insulating layer each having a slit is formed on the top thereof, and a plurality of individual lead wires corresponding to each individual electrode are formed on this insulating layer and within each of the slits.

Further, in the thermal head according to claim 2, a glaze layer is formed on an insulating substrate, and a plurality of heating resistors and a plurality of electrodes for selectively energizing each heating resistor are provided on the glaze layer. In a thermal head in which heating dots are formed on each heating resistor by stacking them in an aligned manner, and the upper part of these heating dots is covered with a protective layer, a large number of strips are placed in parallel on one side of the base on the glaze layer. A protruding common electrode is formed, and a heating resistor layer is formed on the glaze layer and the common electrode so that heating dots are formed between each pair of adjacent strips of the common electrode. , an insulating layer having slits formed on each of the heating dots is formed on the heating resistor layer, and a plurality of individual lead wires corresponding to each heating dot are provided on the insulating layer and in each of the slits. It is characterized by the formation of

Furthermore, in the thermal head according to claim 3, a glaze layer is formed on the insulating substrate, and on the glaze layer, a plurality of heating resistors and a plurality of electrodes that selectively conduct electricity to each heating resistor are respectively provided. In a thermal head in which heating dots are formed on each heating resistor by stacking them in an aligned manner, and the upper part of these is covered with an insulating layer, a heating resistor layer is formed on the glaze layer, and the heating resistor layer is formed on the glaze layer. On the layer, there is a common electrode formed by protruding a large number of strips in parallel on one side of the base so that heating dots are formed between each pair of adjacent strips, and a pair of adjacent strips. A large number of individual electrodes are formed at intervals between the strips, and slits are formed on the heating resistor layer, the common electrode, and each of the individual electrodes. The present invention is characterized in that an insulating layer is formed, and a plurality of individual lead wires connected to each individual electrode are formed on the insulating layer and in each of the slits.

Furthermore, in the thermal head according to claim 4, a glaze layer is formed on an insulating substrate, and a plurality of heating resistors and a plurality of electrodes for selectively energizing each heating resistor are provided on the glaze layer. In a thermal head in which heating dots are formed on each heating resistor by laminating them in an aligned manner, and the top of these is covered with a protective layer, a heating resistor layer is formed on the glaze layer, and the heating resistor layer is formed on the glaze layer. On the body layer, a common electrode is formed by protruding a large number of strips in parallel on one side of the base so that heat-generating dots are formed between each pair of adjacent strips, and these heat-generating resistors An insulating layer having slits formed above each of the heating dots was formed on the body layer and the common electrode, and a plurality of individual lead wires were formed on the insulating layer and connected to each of the heating dots. It is characterized by

[For production]

According to the thermal head of the present invention as set forth in claims 1 to 4 having the above-described configuration, the heat generated by energizing any of the heating dots of the heating resistor layer is transferred to the heating resistor layer. Since the individual lead wires arranged through the insulating layer are interposed between the insulating layer and the protective layer, the transmission performance to the protective layer side is significantly improved by each individual lead wire. As a result, the amount of heat radiated to the insulating substrate through the glaze layer is reduced, thermal efficiency is improved, and printing energy density can be increased.

Furthermore, according to the electrode structure of the present invention, it is possible to minimize the so-called real edge design in which each heating dot of the thermal head is located at the edge of the insulating substrate, so that contact with the platen can be further improved, and a high degree of High-speed printing can be achieved.

[Example] The present invention will be explained below using examples shown in the drawings. It should be noted that structures that are the same as or correspond to those of the conventional structure described above will be described with the same reference numerals in the drawings.

FIG. 1 shows an embodiment corresponding to claim 1, in which a glaze layer 2 made of glass or the like is baked on an insulating substrate 1 made of alumina or the like so that the upper surface is almost flat. Laminated all over.

On the glaze layer 2, there is a film with a thickness of about 0.3 μm,
Electrode layers constituting the electrode 4 made of W or Mo are laminated,
This electrode layer is etched by photolithography to form a common electrode 4a and a plurality of individual electrodes 4b. Among these, the common electrode 4a is formed on almost the entire surface of the insulating substrate 1, and as shown in FIG. Large rectangular base 10°11
and a plurality of elongated linear strips 12 communicating between these base portions 10.11. and,
A straight line is formed so that each individual electrode 4b extends in the same direction as each strip 12 within the widthwise center of each rectangular space 13 surrounded by both bases 10.11 and a pair of strips 12.12. It is formed like an island. Therefore, the common electrode 4a
The overall pattern is a grid pattern.

On the glaze layer 2 and each electrode 4, Ta-8i0
A heating resistor layer constituting the heating resistor 3 made of 2 etc. is laminated, and an insulator layer 14 made of 5 in 2 etc. with a film thickness of about 0.3 μm is laminated on this heating resistor layer. .

Then, the thermal head formed in this way at an intermediate stage of manufacturing is heated in an air atmosphere furnace at about 700°C,
Insulation stabilization treatment is performed by hardening the heating resistor 3 and oxidizing the heating resistor 3 at the pinhole defect portion of the insulating layer 14.

Next, the thermal head, which has been heat-treated and is in an intermediate stage of manufacture, is taken out of the furnace, and the insulator layer 14 directly above the individual electrodes 4b is etched using photolithography, and a plurality of slits are formed in the insulator layer 14. 14A
is formed, and the heating resistor 3 is exposed in each slit 14A. In addition, at the time of this etching, the insulator layer 14 on the external connection terminal (not shown) of the common type FF 14a is also removed at the same time. Thereafter, a high melting point metal W with a thickness of about 0.2 μm is formed on the insulator layer 14. , MOLTi, Cr, etc., and electrode layers made of A, Il, Cu, Au, etc. are sequentially laminated, and these electrode layers are etched using photolithography technology to form a plurality of electrode layers as shown in Fig. 3. individual lead wires 15 are formed at intervals from each other.Each individual lead wire 15 is directly connected to the heating resistor 3 through a corresponding slit 14A formed in the insulating layer 14.
It is electrically connected to each individual N pole 4b via each heating resistor 3, albeit indirectly. Further, each individual electrode 15 is arranged on almost the entire surface of the heating dot 3A of the corresponding heating resistor 3, and is formed so as to be connected to an individual terminal (not shown) for external connection. In addition, in the vicinity of the heating dot 3A, the upper electrode layer made of AJ), Cu, Au, etc. is removed, leaving only the lower electrode layer made of a high melting point metal.

513 on the insulator @14, individual electrode 15, etc.
A protective layer 5 made of N4 or the like and having a thickness of about 3 to 5 μm is laminated. Note that the individual electrodes 15 formed on the surface of the protective layer 5
Irregularities caused by such things can be polished to a smooth finish using wrapping paper or the like.

In this way, the thermal head of this embodiment has the heating resistor 1
4, the grid-shaped common electrode 4a is arranged, and the electrode pattern is configured such that each individual electrode 4b is arranged in a space 13 surrounded by this common electrode 4a. By laminating a heating electrode layer and an insulating layer 14 on the heating resistor 3 and performing high temperature quenching in an air atmosphere, the heating resistor 3 is stabilized and pinhole defects in the insulating layer 14 are repaired. Although the thickness of the insulating layer 14 is made very thin, electrical insulation between the layers can be stably ensured, and electrical and mechanical stability and high workability can be obtained.

In addition, when forming individual electrodes 15 by forming slits 14A in each insulator 1i14 above each heating dot 3A, since the individual electrodes 4b are formed in advance, the accuracy of mask alignment during etching can be made relatively loose. This can facilitate manufacturing.

Note that even if the individual electrodes 4b are not formed at the same height as the common electrode 4a above the space 13 of the common electrode 4a, as described above,
As described above, electricity can be passed between the common electrode 4a and each individual electrode 15 by simply forming the individual electrode 15 in each slit 14A of the insulating layer 14 as described in this embodiment. Therefore, a thermal head can be constructed. This configuration corresponds to claim 2.

Further, each of the individual electrodes 15 does not have to be formed in a so-called comb shape so as to match the slit 14A provided at the center above the heat generating dot 3A, so that it does not have to be formed on the entire surface above each heat generating dot 3A. However, it is easier to manufacture and more effective in absorbing the heat generated in the heat generating resistor 3 by disposing the individual electrode 15 made of a high melting point metal on almost the entire surface above each heat generating dot 3A. In addition, the effect of quickly heating the entire heating drum 1-3A is produced.

As a result, the temperature valve tfi of the heating dot 3A has a peak of 4
The increase in temperature and the expansion of the heat generating area significantly increase the printing energy density with respect to the applied voltage, enabling faster printing and extending the life of the thermal head.

Furthermore, according to the configuration of the electrodes in the thermal head of this embodiment, the heating dots 3A of each heating resistor 3 are positioned at the end of the insulating substrate 1, and the ink ribbon and thermal recording paper backed up by the platen are In a so-called real-edge type thermal head that makes good contact with a heat-sensitive recording member such as the above, the heating dot 3A can be placed very close to the edge of the insulating substrate 1.

FIGS. 4A and 4B show an embodiment of such a real edge thermal head, and in these figures the thermal head is at an intermediate stage in its manufacture.

In FIGS. 4A and 4B, the heating dots 3A of each heating resistor 3 are formed on the top surface of the glaze layer 2 near one end of the insulating substrate 1. A raised portion 2A having a trapezoidal vertical cross-section and extending linearly is formed on.

The common electrode 4a in this embodiment includes one base 10 and a plurality of strips 12 that protrude from one side of the base 10 and whose tips extend to a position close to one end of the insulating substrate 1. It is formed into a so-called comb shape. Also,
Each individual electrode 4b is arranged at the center of each space 13 surrounded on three sides by the base 1o and the pair of strips 12, 12.

The structure in which the heating resistor layer, the insulating layer 14 in which the slits 14A are formed, the individual lead wires 15, and the protective layer 5 are laminated thereon is the same as in the embodiment described above.

The real edge type thermal head constructed in this manner can perform better printing because the heating dots 3A of each heating resistor 3 are located at the end of the insulating substrate 1.

5 and 6 show an embodiment corresponding to claim 3, in which a strip 12 made of glass or the like is laminated by baking on an insulating substrate 1 made of alumina or the like. In this glaze layer 2, a raised part 2A having a substantially trapezoidal longitudinal section is formed at one end of the insulating substrate 1 by etching using photolithography technology, and the contact with the heat-sensitive recording member backed up on the platen is improved. ing. On this glaze layer 2, a heating resistor layer made of Ta-8in3 or the like and having a film thickness of about 0.3 μm is laminated. This heating resistor 12 is subjected to heat treatment at several hundred degrees Celsius in a vacuum hardening furnace in order to improve its thermal stability. On this heat generating resistor layer, about 0.0 mm is made of W, MO, etc.
Electrode layers with a film thickness of 2 μm are laminated, and a common electrode 4a and individual electrodes 4 are formed by etching using photolithography technology.
b is formed in a pattern substantially similar to that of the embodiment shown in FIG. 4 described above. As a result, the heating dots 3A of each heating resistor 3 are located in each space 13 of the common electrode 4a.

On each heating resistor 3 and electrode 4, S i 02
An insulator layer 14 consisting of etc. is laminated with a thickness of about 1 μm,
A slit 14A is formed directly above each of the electrodes 4b for each country by photolithographic etching. At this time, the external connection terminal of the common electrode 4a (not shown)
The upper insulator layer 14 is also removed at the same time. Note that the reliability of the interlayer insulation by this insulator 1114 is determined by first forming S + 02 to a thickness of about 0.5μ by sputtering, and then
Defects such as pinholes can be further prevented by the multilayer structure in which PSG is coated and fired to form a skin of approximately 0.5 μm. It is also effective to divide sputtering into two steps.

On the insulator J114, WX with a film thickness of approximately 0.2 μm is applied.
Electrodes made of MO or other high melting point metals and electrodes made of Ajl 1CU@ for lowering the resistance value are laminated in a stacked manner, and a plurality of individual lead wires 15 spaced apart are formed by etching using photolithography technology. Ru. Above the heat generating dots 3A, the individual electrodes 15 are electrically connected to each individual electrode 4b via slits 14A formed in the insulating layer 14, and are formed so as to be connected to individual terminals for external connection. has been done. Note that in the vicinity of the heating dots 3A of the individual electrodes 15, only the electrodes made of the lower layer high-melting point metal are disposed.

On the insulator layer 14 and each individual electrode 15, Si3N4
A protective layer 5 having a thickness of about 3 to 5 microns is laminated thereon.

According to the thermal head of this embodiment, the same effects as those of the first embodiment described above can be achieved.

Note that also in this embodiment, it is possible to omit each individual electrode 4b.

Further, the present invention is not limited to the embodiments described above, and various changes can be made as necessary.

〔Effect of the invention〕

As explained above, the thermal head according to the present invention has excellent effects of improving thermal efficiency and high-speed thermal response.

[Brief explanation of drawings]

1 to 3 show a first embodiment of a thermal head according to the present invention, in which FIG. 1 is a longitudinal sectional view, FIG. 2 is a plan view showing an electrode pattern, and FIG. 3 is a partial view. The omitted plan view and FIGS. 4A and 4B are side views and plan views of electrode patterns showing the second embodiment of the present invention, and FIGS. 5 and 6 show the third embodiment of the present invention. Figure 5 is a longitudinal sectional view;
Figure 6 is a plan view showing the electrode pattern, Figures 7 and 8.
Each figure is a longitudinal sectional view showing a conventional thermal head. DESCRIPTION OF SYMBOLS 1... Insulating substrate, 2... Glaze layer, 3... Heat generating resistor, 3A... Heat generating dot, 4... Electrode, 4a
...Common electrode, 4b...Individual electrode, 5...Protective layer, 14...Insulator layer, 14A...Slit, 15...
・Individual lead wire.

Claims (1)

[Claims] 1) A glaze layer is formed on an insulating substrate, and a plurality of heating resistors and a plurality of electrodes for selectively energizing each heating resistor are laminated on the glaze layer in an aligned manner. In the thermal head, in which heating dots are formed on each heating resistor, and the upper part of these heating dots is covered with a protective layer, a large number of strips are provided in parallel on one side of the base on the glaze layer. a common electrode, and a large number of individual electrodes arranged at intervals between adjacent pairs of the strips, and a common electrode is formed on the glaze layer, the common electrode, and each individual electrode. A heating resistor layer is formed so that heating dots are formed between each pair of adjacent strips, and on this heating resistor layer, an insulator having slits formed on each of the individual electrodes. 1. A thermal head characterized in that a plurality of individual lead wires corresponding to each individual electrode are formed on the insulating layer and in each of the slits. 2) A glaze layer is formed on an insulating substrate, and on this glaze layer, a plurality of heating resistors and a plurality of electrodes that selectively conduct electricity to each heating resistor are laminated in an aligned manner to form each heating resistor. In the thermal head, in which heat-generating dots are formed on the glaze layer, and the upper part of these is covered with a protective layer, a common electrode is formed on the glaze layer, and the common electrode is formed by protruding a large number of strips in parallel on one side of the base. , forming a heating resistor layer on the glaze layer and the common electrode so that heating dots are formed between each pair of strips adjacent to the common electrode;
An insulating layer in which slits are formed on each of the heating dots is formed on the heating resistor layer, and a plurality of individual lead wires corresponding to each heating dot are provided on the insulating layer and in each of the slits. A thermal head characterized by a formed 3) A glaze layer is formed on an insulating substrate, and on this glaze layer, a plurality of heating resistors and a plurality of electrodes that selectively conduct electricity to each heating resistor are laminated in an aligned manner to form each heating resistor. In the thermal head, a heat generating resistor layer is formed on the glaze layer, and a large number of heat generating dots are formed on one side of the base on the heat generating resistor layer. A common electrode formed by protruding strips in parallel so that heating dots are formed between each pair of adjacent strips, and a common electrode with a space between each pair of adjacent strips. A large number of individual electrodes are formed, and an insulating layer having a slit formed on each electrode is formed on the heating resistor layer, a common electrode, and each individual electrode, and this insulating layer A thermal head characterized in that a plurality of individual lead wires connected to each individual electrode are formed on the top and in each of the slits. 4) A glaze layer is formed on an insulating substrate, and on this glaze layer, a plurality of heating resistors and a plurality of electrodes that selectively conduct electricity to each heating resistor are laminated in an aligned manner to form each heating resistor. In the thermal head, a heat generating resistor layer is formed on the glaze layer, and a large number of heat generating dots are formed on one side of the base on the heat generating resistor layer. A common electrode is formed by protruding parallel strips such that heat-generating dots are formed between each adjacent pair of strips, and each of the heat-generating dots is placed on these heat-generating resistor layers and the common electrode. 1. A thermal head characterized in that an insulating layer in which slits are formed is formed on each dot, and a plurality of individual lead wires are formed on the insulating layer and in each of the heating dots.