JPH08336995A - Thermal head - Google Patents

Abstract

PURPOSE: To protect an adjacent feeder layer by breaking a partly glazed layer through a breaking protective layer formed at a position in close proximity to a common electrode layer for a feeder layer, and thereby, minimizing the generation of chippings. CONSTITUTION: When depositing a protecting layer 18 by sputtering on a thermal resistor layer 13, a feeder layer 14 and a breaking protective layer 15, a difference in the stacking density generates at the edge part of the breaking protective layer 15, and the mechanical strength of the part where such a difference occurs becomes low. Therefore, if a breaking line 19 is provided in close proximity to a common feeder layer 14a, a pitting which generates in the protective layer 18 by grinding is prevented from spreading farther by the edge part of the breaking protective layer 15. Thus the terminal surface of the common feeder layer 14a is no longer exposed. In addition, a partly glazed layer 12 tends to generate partly significant chippings by an impact at the time of grinding. However, the generation of chippings can be minimized by absorption of a grinding impact by the metal layer, if the breaking protective layer 15 is formed in the same type of metal as the feeder layer 14 and the partly glazed layer 12 is ground through the metal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal head used in a thermal printer.

[0002]

2. Description of the Related Art In a thermal head mounted on a thermal printer, for example, a plurality of heating resistor elements are linearly arranged on a substrate, and the heating resistor elements are energized and heated according to information to develop color on a thermosensitive recording paper. It is used for recording or transfer recording on plain paper via an ink ribbon.

FIG. 2 shows an example of a general structure of this conventional thermal head. A partial glaze layer 2 made of glass having a semicircular cross section is formed on the insulating substrate 1, and a heating resistor layer 3 made of Ta2N or the like is formed on the partial glaze layer 2. A power supply layer 4 for supplying power to the heat generation resistor layer 3 is further formed on the heat generation resistor layer 3, and the power supply layer 4 is formed.
The top surface of the partial glaze layer 2 is divided by means such as etching.

The power supply layer 4 is made of, for example, aluminum, and when a voltage is applied between both sides of the dividing portion 4a,
A current flows through the heating resistor layer 3 located on the top surface of the partial glaze layer 2 to generate heat. These protective layers 7 are formed on the heating resistor layer 3 and the power feeding layer 4.
The protective layer 7 is an oxidation resistant layer 5 made of SiO2 or the like for protecting the heat generating resistor layer 3 from deterioration due to oxidation, and the heat generating resistor layer 3 and the power feeding layer 4 from abrasion due to contact with a thermosensitive recording paper (not shown). And a wear resistant layer 6 made of Ta2O5 or the like for protecting the.

In this thermal head, one of the plurality of power feeding layers 4 divided by the central dividing portion 4a is a common power feeding layer 4b.
And the other is the individual power feeding layer 4c. When a voltage is selectively applied to the individual power feeding layer 4c according to information, the heating resistor layer 3 on the top surface of the partial glaze layer 2 generates heat, and this heat causes the oxidation resistant layer 5 and the wear resistant layer 6 to be heated. Protective layer 7
The heat generating portion 7a on the surface of the sheet heats up, and coloring energy is given to the thermal recording paper, the ink ribbon A, and the like. The protective layer 7 is provided so as to cover the entire head surface other than the terminal portion.

In this conventional thermal head, a dividing portion 4a located on the top surface of the partial glaze layer 2 is provided in the power feeding layer 4, and the oxidation resistant layer 5 is formed thereon by means of sputtering or the like.
Then, the protective layer 7 including the abrasion-resistant layer 6 is formed, and braking is performed in the final step to form a thermal head chip.

[0007]

However, in the conventional thermal head, since the heating resistor element has a semicircular cross-section, the contact area with the ink ribbon A is large and the melted ink is transferred to the paper surface by the heat generating portion 7a. Ink ribbon A
Since the distance t until the ink is peeled off is long, the binding force between the ink that has been cooled and transferred by the ink and the ink ribbon A becomes larger than the binding force between the paper surface and the transferred ink. However, there is a problem that the printed characters are incomplete and the printing quality is deteriorated. Further, since the peeling angle θ1 is small, there is a problem that the transferred ink is not well run out and the printed characters are blurred and the printing quality is deteriorated. Further, in order to solve the above problem, if the peeling distance t of the ink ribbon A is shortened and the peeling angle θ1 is increased by bringing the braking position 8 close to the heat generating portion 7a, protection is provided by chipping that occurs during braking. Since the layer 7 is turned over to expose the power feeding layer 4 and the power feeding layer 4 is easily corroded, there is a problem that it cannot withstand long-term use.

An object of the present invention is to solve the above problems and to provide a thermal head which has high printing quality and can withstand long-term use.

[0009]

In order to solve the above-mentioned problems, the thermal head according to claim 1 has a partial grace layer formed on an insulating substrate, and a plurality of heating resistors are formed on the partial grace layer. In a thermal head, the layers are arranged linearly and a power supply layer for supplying electric power to the heating resistor layer, and a protective layer formed on the power supply layer and the heating resistor layer are provided. It is characterized in that the partial glaze layer is braked at a position close to the common electrode body layer of the body layer via a braking protection layer formed of the same material as the power feeding body layer.

A thermal head according to a second aspect is
One end of the braking protection layer is formed on the partial glaze layer.

A thermal head according to a third aspect of the invention is
Common to the partial glaze layer formed near the one end face on the insulating substrate, the heating resistor layer formed on the partial glaze layer, and the individual power feeding layer for supplying power to the heating resistor layer A power feeding layer composed of a power feeding layer, and a braking protection layer formed of the same material as the power feeding layer on the partial glaze layer and at a position close to the common power feeding layer of the power feeding layer. A protective layer formed on the braking protection layer, the power feeding layer and the heat generating resistor layer.

According to the thermal head of the present invention,
The effect that chipping stops at the edge of the braking protection layer during braking and the effect that the braking protection layer absorbs the grinding impact protects the power supply layer and reduces the peeling distance of the ink ribbon. The peeling angle increases.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a sectional view of a thermal head of the present invention.

First, the structure will be described. On the insulating substrate 11, the partial glaze layer 1 made of glass having a semi-circular cross section is formed.
2 is formed, and the heating resistor layer 13 made of Ta2N or the like is formed on the partial glaze layer 12. A power supply layer 14 for supplying power to the heat generation resistor layer 13 is further formed on the heat generation resistor layer 13, and the top surface of the partial glaze layer 12 of the power supply layer 14 is etched. It is divided by such means.

A braking protection layer 15 made of the same material as the power feeding layer 14 is formed on the partial glaze layer 12 close to the common power feeding layer 14a (at intervals of 10 to 20 μm). Then, the heating resistor layer 13 and the power feeding layer 14
The protective layers 18 are formed on the braking protective layer 15 by means such as sputtering.

The protective layer 18 is composed of a first protective layer 16 made of SiO2 or the like for protecting the heating resistor layer 13 from deterioration due to oxidation and a second protective layer 17 made of Ta2O5 or the like for preventing abrasion due to contact. There is. Finally, the braking protection layer 15 is ground with a dicing saw and braked on the thermal head chip.

Next, the operation will be described. When the protective layer 18 is sputter-deposited on the braking protection layer 15, a difference in the deposition density of the vapor deposition film occurs at the edge portion of the braking protection layer 15, and the mechanical strength of that portion becomes low, so that common power feeding is possible. Even if the braking line 19 is provided in the vicinity of the body layer 14a, chipping of the protective layer caused by grinding with a dicing saw is stopped at the edge portion of the braking protective layer 15 having low mechanical strength as in the conventional case, and common power feeding is performed. The end surface of the body layer 14a is not exposed, and the partial glaze layer 12 has a property of partially producing large chipping due to an impact during grinding because it is an amorphous glass. 15 is a power feeding layer 1
When the partial glaze layer 12 is formed of the same metal as that of No. 4 and the partial glaze layer 12 is ground with a dicing saw through the metal, the metal layer absorbs a grinding impact, so that the chipping of the vitreous partial glaze layer 12 is minimized. Since the adjacent end faces of the common power feeding layer 14 are not exposed, it is possible to endure long-term use.

Further, the braking line 19 can be provided in the vicinity of the common electrode layer 14a, and the heating portion 18 is provided.
Since a can be brought closer to the edge of the thermal head, the distance T from melting and transferring the ink of the ink ribbon A to peeling the ink ribbon A can be shortened, and the peeling angle θ of the ink ribbon A can be reduced.
Since 2 can be increased, high quality printing with good ink cut-off without ink peeling can be achieved.

[0019]

As described above, in the thermal head of the present invention, the braking protection layer formed of the same material as the power feeding layer is provided at a position close to the common power feeding layer of the power feeding layer. Since the partial glaze layer is braked, the braking protection layer can be formed in the same process as the power feeding layer without increasing the manufacturing process, and the chipping that occurs during braking is the edge of the braking protection layer. By the effect of stopping at the part, chipping is minimized, adjacent power supply layers are protected, the peeling distance of the ink ribbon is shortened, and the peeling angle becomes large, so it can withstand long-term use, and It has remarkable effects such as high quality printing.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a thermal head of the present invention.

FIG. 2 is a cross-sectional view showing a conventional thermal head.

[Explanation of symbols]

 11 Insulating Substrate 12 Partial Glaze Layer 13 Heating Resistor Layer 14 Power Supply Layer 15 Braking Protective Layer 18 Protective Layer 19 Braking Line

Claims (3)

[Claims] 1. A feeder layer for forming a partial grace layer on an insulating substrate, linearly arranging a plurality of heating resistor layers on the partial grace layer, and supplying electric power to the heating resistor layer. And a protective layer formed on the power supply layer and the heating resistor layer, the same material as the power supply layer is provided at a position close to the common electrode layer of the power supply layer. A thermal head, characterized in that the partial glaze layer is braked through the formed braking protection layer. 2. The braking protection layer has one end formed on the partial glaze layer.
The thermal head described in. 3. A partial glaze layer formed in proximity to one end face portion on an insulating substrate, a heating resistor layer formed on the partial glaze layer, and an individual unit for supplying electric power to the heating resistor layer. A power feeding layer composed of a power feeding layer and a common power feeding layer, and formed of the same material as the power feeding layer on the partial glaze layer and at a position close to the common power feeding layer of the power feeding layer. A thermal head comprising: a braking protection layer; and a protection layer formed on the braking protection layer, the power supply layer and the heating resistor layer.