KR20000071390A - Thermal head and processing method thereof - Google Patents

Abstract

The object of the present invention is to provide a double line thermal head and a preheat thermal head, which are difficult to realize in the related art, by a simple process, and for this purpose, the present invention is directed to a ceramic substrate, The electrode films 105 and 106 are patterned. The portion exposed between the electrode film 105 and the electrode film 106 becomes the heat generating portion 104. The insulating layer 107 is formed thereon, and the surface thereof is polished to eliminate the step. The insulating layer 107 has a structure in which heat generated in the heat generating section 104 is easily transmitted to the surface of the thermal head. On the insulating layer 107, the resistive film 108 is patterned. The electrode films 110 and 111 are patterned on the resistor film 108. The portion exposed between the electrode film 110 and the electrode film 111 becomes the heat generating portion 109. The heat generated by the heat generating unit 104 is configured to be easily transmitted to the surface of the thermal head via the electrode film 110. Finally, the protective film 112 is formed, and the surface thereof is polished to eliminate the step.

Description

Thermal head and manufacturing method thereof

The present invention relates to a thermal head used as a double line thermal head or a pre-heat type thermal head and a method of manufacturing the same.

In view of increasing the printing speed, a double-line thermal head in which a plurality of heat generating resistors are arranged in two rows in parallel is invented (see Japanese Patent Application No. 62-217627). The double-line thermal head allows two lines to be printed at the same time, which in principle reduces the print time by half.

Further, in view of increasing the printing speed, a preheat type thermal head using a metal substrate is disclosed in Japanese Patent Application Laid-Open No. 8-300695.

However, in the double-line thermal head, the thermal expansion coefficients between the common electrode and the aluminum substrate using the bulk metal are different, so that peeling occurs at both junction interfaces.

Due to the peeling of the common electrode and the aluminum substrate, there is a problem that a thermal stress is applied to the thin film electrode formed on the common electrode and the thin film having a weak mechanical strength is damaged.

In addition, it is very difficult to lubricate the bulk metal and the aluminum substrate so that the thin film is cracked when a thin film is formed thereon.

In the double head thermal head, it is very difficult to process the common electrode to the dot level width of the thermal head. It is very difficult to closely attach or embed the common electrode so that there is no gap or gap.

Even if practical use is possible, in a double-line thermal head, since a gap equal to the width of a general electrode is formed between two rows of heat generating resistors, high density printing cannot be performed.

In addition, in the preheat type thermal head, in the step of forming a common electrode on a stainless substrate by etching or machining, it is difficult to form a predetermined shape with a predetermined shape over the entire length of the substrate and the cost is high.

In the process of firing glass paste by screen printing, a stainless substrate cannot raise the firing temperature to the same extent as a ceramic substrate because oxide growth is a problem.

For this reason, if the viscosity of the glass paste is not lowered sufficiently, bubbles remain in the glass paste.

In addition, in the preheat type thermal head, when lapping or polishing is performed to expose the common electrode to the surface, bubbles appear on the surface and the thin film formed thereon is damaged. It is difficult and expensive to make the lapping or polishing for exposing the common electrode to the surface over the entire length of the substrate.

Even if it is practical, the preheat type thermal head has a common electrode between two rows of heating resistors, so that the paper passes through the heating resistors in the first row and reaches the heating resistors in the second row. Wasteful

The present invention has been made under such a background, and an object thereof is to provide a double line thermal head and a preheat thermal head, which have been difficult to realize in the past, by a simple process.

Moreover, an object of this invention is to implement | achieve a high density printing compared with the conventional double line thermal head.

In addition, it is an object of the present invention to provide a thermal head having a higher thermal efficiency than a conventional preheat thermal head.

1 is a cross-sectional view showing a configuration example of a thermal head according to an embodiment of the present invention;

2 is a plan view showing a structural example of a thermal head according to a first embodiment of the present invention;

3 is a plan view showing a configuration example of a thermal head according to a second embodiment of the present invention;

4 is a graph showing a relationship example of applied energy and color development concentration in the thermal head according to the second embodiment;

It is a top view which shows the structural example of the thermal head which concerns on 3rd Embodiment of this invention.

* Explanation of the sign

101: gas 104, 109: heat generating portion

105, 106, 110, 111: electrode film 107: insulating layer

112: protective film

The invention of claim 1 further includes a first electronic circuit pattern layer having an electronic circuit pattern formed on a ceramic substrate, an insulating layer formed on the first electronic circuit pattern layer, and an electronic circuit pattern formed on the insulating layer. And an electronic circuit pattern layer.

The invention of claim 2 further includes a first electronic circuit pattern layer having an electronic circuit pattern including a heat generating portion formed on a ceramic substrate, an insulating layer formed on the first electronic circuit pattern layer, and a heat generating portion formed on the insulating layer. And a second electronic circuit pattern layer having an electronic circuit pattern.

The invention according to claim 3 further includes a first electronic circuit pattern layer having an electronic circuit pattern including a heat generating portion formed on a ceramic substrate, an insulating layer formed on the first electronic circuit pattern layer, and a heat generating portion formed on the insulating layer. And a second electronic circuit pattern layer having an electronic circuit pattern, wherein heat generated in the first electronic circuit pattern layer is transmitted to the thermal head surface through the insulating layer and the second electronic circuit pattern layer. It is done.

The invention according to claim 4, wherein the heat generating portion of the first electronic circuit pattern layer and the heat generating portion of the second electronic circuit pattern layer are disposed in a sub-scanning direction. It is characterized by.

5. The invention according to claim 5, wherein the heat generating portion of the first electronic circuit pattern layer is shifted to a paper conveying upstream direction, and the heat generating portion of the second electronic circuit pattern layer is conveyed in a paper conveying downstream direction. A part or all of the second electronic circuit pattern layer heat generating unit overlaps with a part of the first electronic circuit pattern layer heat generating unit.

6. The invention according to claim 6, wherein the heat generating portion of the first electronic circuit pattern layer and the heat generating portion of the second electronic circuit pattern layer are within 1 dot in the main scanning direction. It is arrange | positioned at the distance shifted.

7. The invention according to claim 1, wherein the range of the insulating layer is a part of the entire thermal head, and the electrode of the first electronic circuit pattern layer is connected to a bendable electrode. It is characterized by.

8. The invention according to claim 8, wherein the range of the insulating layer is a part of the entire thermal head, and an electrode of the first electronic circuit pattern layer is connected to a control IC. do.

9. The invention according to claim 9, wherein the electronic circuit pattern of the second electronic circuit pattern layer is in the range in which the electronic circuit pattern of the first electronic circuit pattern layer exists below. And formed on the insulating layer in a limited manner.

The invention according to claim 10 further comprises forming a first electronic circuit pattern layer having an electronic circuit pattern on a ceramic substrate, forming an insulating layer over the first electronic circuit pattern layer, and having an electronic circuit pattern over the insulating layer. A second electronic circuit pattern layer is formed.

The invention according to claim 11 comprises forming a first electronic circuit pattern layer having an electronic circuit pattern including a heat generating portion on a ceramic substrate, forming an insulating layer on the first electronic circuit pattern layer, and generating heat on the insulating layer. A second electronic circuit pattern layer having an electronic circuit pattern including a portion is formed.

<1st embodiment>

EMBODIMENT OF THE INVENTION Hereinafter, 1st Embodiment of this invention is described with reference to drawings.

1 and 2 are diagrams showing an example of the configuration of the thermal head according to the first embodiment of the present invention.

In the case of this embodiment, FIG. 1 is sectional drawing A-A 'of FIG.

In Fig. 1, the material of the base 101 is an insulating ceramic, and alumina is generally used.

The surface of the base 101 is polished or the like as necessary.

Then, on the substrate 101, after partial glass glaze 102 repeats the step of screen printing and drying the glass paste once or several times, by firing at about 1000 to 1300 占 폚. Is formed.

According to the base 101 and the partial glass shade 102, a ceramic substrate is formed.

However, the ceramic substrate used in the present invention is not limited to this, it is possible to use a general ceramic substrate.

Specifically, the board | substrate which consists only of the shape | molded alumina, the board | substrate which carried out the etching shaping | molding of glass alumina gaseous phase, etc. can be used.

After the formation of the ceramic substrate, the first electronic circuit pattern (Pattern) is formed on the ceramic substrate in the following order.

First, the resistive film 103 is formed by, for example, sputtering of TaSiO ₂ and patterned according to photolithography and etching.

The pattern of the resistor film 103 may be in the same dot shape as that of the heat generating portion 109 of FIG. 2, or may be all connected or partially connected to the same dot as the heat generating portion 104.

However, the material, film formation method, and patterning method of the resistor film are not limited to these.

Specifically, the material may be NbSiO ₂ , NiCr, NiCrSi, or the like, and the film forming method may be vacuum deposition, CVD, temperature, etc., and the patterning method may be wet etching, chemical dry etching, or the like.

Next, the electrode films 105 and 106 are formed by, for example, sputtering of an Al alloy, and patterned by photolithography and etching.

The patterns of the electrode films 105 and 106 may be divided for each dot as in the electrode film 111 of FIG. 2, or may be all connected or partially connected to the electrode film 105.

Here, the portion exposed between the electrode film 105 and the electrode film 106 of the resistor serves as the heat generating portion 104.

The length of the heat generating unit 104 may be different from the length of the heat generating unit 109.

However, the material, the film formation method, and the patterning method of the electrode film are not limited to these.

Specifically, the material may be the same as in the case of the resistive film in the film forming method and the patterning method such as Cu, Au, W, Mo, or an alloy thereof.

In addition, the electrode film 106 is turned in the letter c at both ends of the thermal head and extends in the same direction as the electrode film 105.

Next, the insulating layer 107 is formed to a thickness of about 8 μm in the range of B-B ', for example, by sputtering of SiO ₂ .

At this time, the right end of the electrode film 106 is on the left side of the line B 'and is electrically insulated from the first and second layers.

The electrode film 105 and the electrode film 106 are connected to a flexible electrode or the like in front of each other (not shown).

However, the insulating layer 107 is for insulating the electronic circuit patterns of the 1st layer and the 2nd layer, The material, the film formation method, and the thickness are not limited to these.

Specifically, the material is a resistive film in a film formation method or a patterning method such as Ta ₂ O ₅ , SiC, SiAlON, SiN, DLC (Diamond Like Carbon), BN, BO ₂ , TiO ₂ , TiN, or a compound or mixture thereof. Is the same as

The insulating layer 107 is made of a material having high thermal conductivity so that heat generated in the heat generating section 104 can be easily transferred to the surface of the thermal head, and the insulating layer 107 is preferably formed to a minimum thickness necessary for insulation.

The insulating layer 107 may be formed of a plurality of layers of two or more materials.

The insulating layer 107 can step on the surface by the thickness of the electrode films 105 and 106. Then, it is preferable to remove the step by polishing the surface of the insulating layer 107.

Next, the second electronic circuit pattern is formed on the insulating layer 107 in the following order.

First, the resistive film 108 is formed by, for example, sputtering of TaSiO ₂ and patterned according to photolithography and etching.

The pattern of the resistor film 108 is, for example, a pattern divided for each dot as shown in FIG. 2.

At this time, the left end of the resistor film 108 is located to the right of the B line, and is electrically insulated from the first and second layers.

However, the material, the film formation method, and the patterning method of the resistor film are not limited to these, but may be the same as the resistor film of the first layer.

Next, the electrode films 110 and 111 are formed by, for example, sputtering of an Al alloy, and patterned according to photolithography and etching.

The patterns of the electrode films 110 and 111 are combined into the resistor film 108 to be divided into dots.

Here, the portion exposed between the electrode film 110 and the electrode film 111 of the resistor serves as the heat generating portion 109.

For example, in FIG. 2, the left end of the heat generating portion 109 and the right end of the heat generating portion 104 are arranged so as to deviate in the sub-scanning direction so as to overlap with a positive cut.

The arrangement of the heat generating portion 109 and the heat generating portion 104 is not limited to this, so that at least a part of the heat generating portion 109 and the heat generating portion 104 overlaps, or the heat generating portion 109 and the heat generating portion 104 are overlapped. ) So as not to overlap, it is possible to arrange freely in the left or right direction of Fig. 1, respectively.

However, the material, the film formation method, and the patterning method of the electrode film are not limited to these, but may be the same as the first electrode film.

Since the heat generated by the heat generating part 104 of the first layer is transmitted to the surface of the thermal head through the electrode film 110 of the second layer, the electrode film of the second layer is preferably high in thermal conductivity and strong in heat resistance.

The electrode film 110 is connected to the front surface extending to the left side to form a common electrode film 113. At this time, the left end of the general electrode film 113 is on the right side of the B line, and the first and second layers are electrically insulated.

The general electrode film 113 is connected to a flexible electrode or the like (not shown).

The electrode film 111 is connected to a control IC by wire bond or the like (not shown).

Finally, the protective film 112 is formed into a film having a thickness of about 5 μm by, for example, sputtering of SiAlON.

However, the protective film 112 is for protecting an electronic circuit pattern from abrasion and oxidation, and the material, the film formation method, and the thickness are not limited to these.

Specifically, the protective film 112 may be the same as the insulating layer.

The protective film 112 may be formed of a plurality of layers of two or more materials.

The passivation film 112 may have a step on the surface by the thickness of the electrode films 110 and 111. Here, it is preferable to remove the step by polishing the surface of the protective film 112 or the like.

Next, a method of controlling the thermal head according to the present embodiment will be briefly described below.

The heat generation unit 104 generates heat to generate heat corresponding to the bias energy, thereby generating the heat generation unit 109 to perform dot gradation printing.

This process is carried out while conveying the paper, thereby printing the entire print range.

In detail, it conforms to JP 08-300695 and JP 08-300696.

<2nd embodiment>

EMBODIMENT OF THE INVENTION Hereinafter, with reference to drawings, 2nd Embodiment of this invention is described.

1 and 3 are diagrams showing a structural example of a thermal head according to a second embodiment of the present invention.

In the case of this embodiment, FIG. 1 is sectional drawing A-A 'in FIG.

In this embodiment, unlike the first embodiment, the pattern of the resistor film and the electrode film of the first layer is divided into dots.

The rest of the procedure is the same as in the first embodiment.

For example, in FIG. 3, the left end of the heat generating portion 109 and the right end of the heat generating portion 104 are arranged so as to deviate in the sub-scanning direction so as to overlap in a square shape.

The arrangement of the heat generating portion 109 and the heat generating portion 104 is not limited to this, so that at least a portion of the heat generating portion 109 and the heat generating portion 104 overlaps, or the heat generating portion 109 and the heat generating portion 104 are overlapped. It is possible to arrange freely in the left or right direction in Fig. 1 so as not to overlap each other.

Next, a method of controlling the thermal head according to the present embodiment will be briefly described below.

The heat generating unit 104 and the heat generating unit 109 are simultaneously heated to perform dot grayscale printing for two lines at a time.

Next, in the case of the sublimation method, the paper and the ribbon are advanced, and in the self-coloring method, the paper is advanced for two lines.

This is repeated to print the entire print range (see Japanese Patent Application No. 62-217627).

In the thermal head according to the present embodiment, applied energy and color development are used for the case of printing by the first layer and the case of printing by the second layer using a sublimation type paper and an ink ribbon (cyan). The relationship with concentration is shown in FIG.

In this figure, each of the first and second layers is a case in which only one side of the heat is generated.

In the case of printing on the first layer, heat generated in the heat generating unit 104 is transmitted to the surface of the thermal head through the insulating layer 107, the resistive film 108, the electrode film 110, and the protective film 112. You must.

On the other hand, in the case of printing on the second layer, heat generated in the heat generating portion 109 is transmitted to the thermal head surface only through the protective film 112.

For this reason, it is felt that a considerable amount of energy is required in excess of the print in the first layer compared with the print in the second layer, but in practice, as shown in FIG. 4, the increase in the required energy is 10% or less.

Therefore, in the case of printing two lines simultaneously by the first layer and the second layer, the energy for applying a voltage to the first layer may be increased by that portion.

Third Embodiment

EMBODIMENT OF THE INVENTION Hereinafter, with reference to drawings, 3rd Embodiment of this invention is described.

1 and 5 are diagrams showing a structural example of a thermal head according to a third embodiment of the present invention.

In the case of this embodiment, FIG. 1 is sectional drawing A-A 'in FIG.

In this embodiment, unlike the first embodiment, the pattern of the resistor film and the electrode film of the first layer is divided into dots. In addition, in this embodiment, arrangement | positioning of the heat generating part 104 and the heat generating part 109 is shifted | deviated from the main scanning direction for 0.5 dots, unlike 2nd Embodiment.

However, the amount placed in the main scanning direction is not limited to this, but can be adjusted from 0 to an arbitrary number of dots.

The rest of the procedure is the same as in the first embodiment.

For example, in FIG. 5, the left end of the heat generating portion 109 and the right end of the heat generating portion 104 are arranged in a sub-scan direction so as to overlap in a positive shape.

The arrangement of the heat generating portion 109 and the heat generating portion 104 is not limited to this, so that at least a part of the heat generating portion 109 and the heat generating portion 104 overlaps, or the heat generating portion 109 and the heat generating portion 104 are overlapped. It is possible to arrange each other freely in the left or right direction in Fig. 1 so that) does not overlap.

Next, a method of controlling the thermal head will be briefly described below.

The heat generating unit 104 and the heat generating unit 109 are simultaneously heated to perform dot grayscale printing for two lines at a time.

At this time, like the second embodiment, the energy for applying a voltage to the first layer may be increased as compared with the second layer.

Subsequently, in the case of the sublimation method, the paper and the ribbon are conveyed for two lines, for example, in the self color development method.

This is repeated to print the entire print range (see Japanese Patent Application Laid-Open No. 09-128924).

However, the conveyance amount of the paper can be adjusted up to 0.5 to 2 dots by the arrangement of the heat generating unit 104 and the heat generating unit 109.

As mentioned above, although embodiment of this invention was described above with reference to drawings, a specific structure is not limited to this embodiment, Even if there exists a design change etc. of the range which does not deviate from the summary of this invention, it is contained in this invention.

As described above, according to the present invention, since a double line thermal head and a preheat thermal head can be realized by using a ceramic substrate which is generally used, the quality is stable.

In addition, since there is no need to use a stainless steel substrate or a general electrode made of metal, a problem caused by the difference in the coefficient of thermal expansion between the metal and the glass grade or alumina substrate does not occur.

In addition, since it is only necessary to repeat the same process as before, it is simple and inexpensive.

In addition, unlike the conventional double line thermal head, since there is no common electrode between two rows of resistance heating elements, printing can be performed at high density without gaps between two rows.

In addition, unlike conventional preheat thermal heads, since there is no common electrode between two rows of resistance heating elements, waste of heat until passing through the first row of heating resistors and then through the second row of heating resistors is eliminated. none.

In addition, since the heat generated in the first electronic circuit pattern layer is transmitted to the surface of the thermal head through the insulating layer and the second electronic circuit pattern layer formed thereon, the heat generating portion and the second electronic circuit pattern layer of the first electronic circuit pattern layer. The heat generating portion can be freely arranged without limitation.

Claims (11)

A first electronic circuit pattern layer having an electronic circuit pattern formed on the ceramic substrate, An insulating layer formed on the first electronic circuit pattern layer; A second electronic circuit pattern layer having an electronic circuit pattern formed on the insulating layer; Thermal head, characterized in that consisting of. A first electronic circuit pattern layer having an electronic circuit pattern including a heat generating portion formed on a ceramic substrate, An insulating layer formed on the first electronic circuit pattern layer; A second electronic circuit pattern layer having an electronic circuit pattern including a heating unit formed on the insulating layer; Thermal head, characterized in that consisting of. A first electronic circuit pattern layer having an electronic circuit pattern including a heat generating portion formed on a ceramic substrate, An insulating layer formed on the first electronic circuit pattern layer; A second electronic circuit pattern layer having an electronic circuit pattern including a heating unit formed on the insulating layer; Made up of The heat generated in the first electronic circuit pattern layer is transmitted to the surface of the thermal head through the insulating layer and the second electronic circuit pattern layer. The method according to any one of claims 1 to 3, And a heat generating portion of the first electronic circuit pattern layer and a heat generating portion of the second electronic circuit pattern layer in a sub-scan direction. The method according to any one of claims 1 to 3, Shift the heat generating portion of the first electronic circuit pattern layer in the paper conveyance upstream direction, Shifting the heat generating portion of the second electronic circuit pattern layer in the paper conveyance downstream direction, And a part or all of the second electronic circuit pattern layer heating part overlaps with a part of the first electronic circuit pattern layer heating part. The method according to any one of claims 1 to 4, And a heat generating portion of the first electronic circuit pattern layer and a heat generating portion of the second electronic circuit pattern layer are disposed at a distance of one dot or less in the main scanning direction. The method according to any one of claims 1 to 3, The range of the insulating layer is a part of the entire thermal head, And connecting the electrode of the first electronic circuit pattern layer with a bendable electrode. The method according to any one of claims 1 to 3, The range of the insulating layer is a part of the entire thermal head, And the electrode of the first electronic circuit pattern layer is connected to a control IC. The method according to any one of claims 1 to 3, The thermal head of the said 2nd electronic circuit pattern layer was formed only on the said insulating layer in the range in which the electronic circuit pattern of the said 1st electronic circuit pattern layer exists below. Forming a first electronic circuit pattern layer having an electronic circuit pattern on the ceramic substrate, An insulating layer is formed on the first electronic circuit pattern layer, And forming a second electronic circuit pattern layer having an electronic circuit pattern on the insulating layer. Forming a first electronic circuit pattern layer having an electronic circuit pattern including a heating part on a ceramic substrate, An insulating layer is formed on the first electronic circuit pattern layer, And forming a second electronic circuit pattern layer having an electronic circuit pattern including a heating part on the insulating layer.