JP2000085169A - Thermal head and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance production quality, print heat efficiency and print quality by decreasing electrical resistance while improving adhesion of a common conductive layer thereby reducing heat generation loss. SOLUTION: At least a heat insulation layer 2, common conductive layers 4a-4e, interlayer insulation layers 5a, 5b having contact holes 6, a plurality of heating resistors 9, individual electrodes 8a, 8b being connected with the heating resistors 9, and common electrodes 7a, 7b for connecting the common conductive layers 4a-4e, electrically with the heating resistors through the contact holes 6 are laminated on the upper surface of a heat dissipating plate 1. The common conductive layers 4a-4e include five layers, i.e., a first common conductive layer 4a of Ta cermet, a second common conductive layer 4b of Cr, a third common conductive layer 4c of Cu, a fourth common conductive layer 4d of Cr, and a fifth common conductive layer 4e of Ta cermet laminated sequentially.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal head and a method of manufacturing the same, and more particularly, to a real edge type thermal head having a common electrode as a multilayer wiring and a method of manufacturing the same.

[0002]

2. Description of the Related Art In general, a thermal head as a recording head mounted on a thermal printer has a plurality of heating elements formed of heating resistors arranged in a line or a plurality of lines on a heat radiating substrate, and based on print information. By selectively energizing and heating each heating element, various types of recording, such as color recording on thermal recording paper, or melting and transferring the ink on the ink ribbon to plain paper or OHP paper, etc. Recording is performed on a medium.

In such a conventional thermal head, a convex portion is formed near an end of a heat insulating layer laminated on an upper surface of a heat radiating substrate, and a common conductive layer and an interlayer are formed on the upper surface of the heat insulating layer. An insulating layer is laminated, and on the upper surface of this interlayer insulating layer, a lower electrode connected to the common conductive layer via a contact hole and energizing the heating resistor is laminated,
A real-edge type thermal head is used in which a heating resistor and an upper electrode are stacked on the upper surface of the lower electrode, and a common electrode having a surface thereof covered with a protective layer is multilayered.

FIG. 3 shows such a conventional thermal head. A heat insulating layer 12 made of glass or the like is provided on the surface of a heat dissipation substrate 11 made of an insulating ceramic such as alumina.
Is formed on the entire surface, and a convex portion 13 of the heat insulating layer 12 is formed in the vicinity of one end of the heat radiation substrate 11 by means such as etching.

A first common conductive layer 14a made of a refractory metal such as Cr and having a thickness of about 1 μm and a cermet made of a mixture of Ta and an insulator such as TaSiO ₂ are formed on the upper surface of the convex portion 13. (Hereinafter referred to as “Ta cermet”) and the like and having a thickness of about 1 μm.
Are sequentially laminated by sputtering or the like.

An oxidation-resistant material made of an oxidation-resistant alloy, ceramic, cermet, or the like is formed on the upper surface of the second common conductive layer 14b to a thickness of about 0.2 μm by sputtering or the like. Thus, an oxidation-resistant mask layer having a predetermined shape is formed only at the position where the contact hole is formed near the end of the heat dissipation substrate 11. In this state, the entire surface of the heat dissipation substrate 11 is thermally oxidized at a temperature of about 700 ° C., so that the surface of the second common conductive layer 14 b that is not masked by the oxidation-resistant mask layer becomes a pattern of the oxidation-resistant mask layer. Accordingly, a first interlayer insulating layer 15a having a thickness of several thousand angstroms is formed by the insulating oxide ceramic layer. Thereafter, the oxidation-resistant mask layer is removed by etching.

On the upper surface of the first interlayer insulating layer 15a, a second interlayer insulating layer 15b made of an insulating ceramic such as SiO ₂ having excellent insulating properties is laminated. , And 15b have a two-layer structure, whereby the reliability of the interlayer insulation is further enhanced. In the second interlayer insulating layer 15b, a contact hole 16 is formed by photolithography at a position corresponding to the position where the oxidation-resistant mask layer is formed, thereby completing a multilayer wiring substrate having a common electrode.

On the upper surface of this multilayer wiring board, Mo, C
By laminating an electrode material composed of a group of refractory metals such as r and W by sputtering or the like, the second common conductive layer 14 is formed.
The electrode patterns of the lower-layer common electrode 17a and the lower-layer individual electrode 18a which are connected to the lower electrode b are formed on the upper surfaces of the lower-layer common electrode 17a and the lower-layer individual electrode 18a, respectively. The body 19 is stacked, and a plurality of heating resistors 19 are linearly arranged according to the number of dots by the photolithography technique. Further, the heating resistor 1
9 to supply power energy,
Upper common electrode 1 made of Cu or the like and having a thickness of about 2 μm
7b and the upper individual electrode 18b are respectively laminated by sputtering or the like.

Further, on the upper surface of the heating resistor 19, the upper common electrode 17b and the upper individual electrode 18b, except for the connection terminal portion of the external circuit, an acid-resistant material such as sialon is used to prevent oxidation and wear. A protective layer 20 made of a material having a high degree of hardness and having a thickness of about 5 μm is laminated and coated by sputtering or the like.

Then, after a post-process such as a terminal plating process, the heat dissipation board 11 is diced to manufacture a block (chip) -shaped thermal head.

In such a conventional thermal printer using a real edge thermal head with multilayer wiring, the thermal head is connected to a thermal transfer ink ribbon (not shown) in the case of ordinary recording paper. In a state where the recording paper is pressed against the recording paper, and in the case of a thermosensitive recording paper, while the recording paper is pressed against the recording paper, a current is applied to the upper-layer individual electrode based on a predetermined print signal to cause a desired heating resistor to generate heat. Thus, the desired printing is performed by melting the ink of the ink ribbon and transferring the ink to the paper, or by coloring the heat-sensitive recording paper.

[0012]

In such a conventional thermal head in which a common electrode is formed in a multilayer wiring, the first common conductive layer 14a is formed of C having high heat resistance, adhesion and hardness.
Since the electric resistance of the refractory metal is about 10 times or more as large as that of Cu, the thickness of the first common conductive layer 14a is about 1 μm.
By making the pattern of the first common conductive layer 14a substantially over the entire surface of the heat dissipation substrate 11,
It was necessary to reduce the voltage drop (common drop) generated at the common electrode portion to prevent the print quality from being lowered.

However, when the first common conductive layer 14a made of a high-melting-point metal is used with a large thickness, a sputtering film of a high-melting-point metal generally has a large tensile stress. And the residual stress increases,
The first common conductive layer 14a is formed by a high-temperature thermal oxidation process for forming the first interlayer insulating layer 15a in a later process, or a thermal shock caused by a high-temperature vacuum heat treatment for stabilizing the heating resistor 19 or the like.
However, there is a problem that the reliability of the interface adhesion of the thermal head is reduced, and the production quality and production yield of the thermal head are reduced.

When the pattern of the first common conductive layer 14a is formed substantially over the entire surface of the heat dissipation board 11,
In proportion to the area of the first common conductive layer 14a, the probability of occurrence of interlayer insulation failure due to leakage from a defective portion of the heat insulation layer 12 or interlayer insulation layer increases, and the problem that the manufacturing quality and the manufacturing yield decrease is reduced. Have. Further, the first common conductive layer 14a is arranged from directly below the heating resistor 19 to near the end of the heat dissipation substrate 11, and
Since the refractory metal such as Cr is excellent in thermal conductivity, if the first common conductive layer 14a is provided with a large thickness, the heat generated in the heating resistor 19 passes through the first common conductive layer 14a. There is also a problem that the heat is dissipated, the rise in the heat generation temperature of the heat generating resistor 19 is slowed down, the print heat efficiency is reduced, and the print quality is deteriorated.

The present invention has been made in view of the above-mentioned problems, and can improve the adhesion of the common conductive layer, reduce the electric resistance and reduce the heat loss, and improve the manufacturing quality and It is an object of the present invention to provide a thermal head and a method of manufacturing the same, which can increase the production yield and improve the printing thermal efficiency and the printing quality.

[0016]

According to a first aspect of the present invention, there is provided a thermal head having at least a heat insulating layer, a common conductive layer, and a contact hole on an upper surface of a heat radiating substrate. Layers, multiple heating resistors,
A thermal head in which individual electrodes connected to each of the heating resistors and a common electrode for electrically connecting the common conductive layer and the heating resistor via the contact hole are stacked. The conductive layers are a first common conductive layer made of Ta cermet, a second common conductive layer made of Cr, a third common conductive layer made of Cu, a fourth common conductive layer made of Cr, and a fifth common conductive layer made of Ta cermet. Wherein the thermal head is formed of five layers obtained by sequentially laminating.

According to the first aspect of the present invention, Ta
A first common conductive layer made of cermet or the like is provided with a heat insulating layer and a second common conductive layer.
Since the first common conductive layer functions as an adhesive layer for further stabilizing the adhesion to the common conductive layer, chipping of the laminated film can be reduced by the first common conductive layer, and the production quality and the production yield can be reduced. Stabilization can be achieved.

Further, since the third common conductive layer is formed of Cu having a small electric resistance, a voltage drop when a voltage is applied to each heating resistor can be significantly reduced, and variations in print density can be achieved. It is possible to realize high printing quality without any defects, furthermore, it is possible to remarkably reduce the pattern area of the third common conductive layer with respect to the substrate area, and to cause formation defects (holes and projections) of the heat insulating layer and the interlayer insulating layer. The probability of occurrence of insulation failure between layers can be significantly reduced.

Further, by providing the second common conductive layer made of Cr, when the heat generating resistor generates heat, heat loss due to heat radiation from the second common conductive layer can be reduced. Can be increased, and as a result, the printing thermal efficiency can be significantly improved.

Further, the third common conductive layer made of Cu is
Since it is sandwiched between the second common conductive layer and the fourth common conductive layer made of r, even if a high-temperature heat treatment step is performed, a decrease in adhesion due to oxidation and diffusion of the Cu layer is reliably prevented. Therefore, the production quality and the production yield can be stabilized.

According to a second aspect of the present invention, in the first aspect, the common conductive layer is formed by laminating the first common conductive layer, which is the lowermost layer, on the entire surface of the heat insulating layer. On the second common conductive layer, a third common conductive layer and a fourth common conductive layer are stacked on the second common conductive layer from immediately below the heating resistor to near the end of the heat dissipation substrate. Wherein the fifth common conductive layer is formed by laminating in the vicinity of the row of heating resistors, and by laminating the fifth common conductive layer on the entire surface of the heat dissipation substrate on the upper surface of each common conductive layer.

According to the second aspect of the present invention, Ta
Since the first common conductive layer made of cermet or the like is laminated on the entire surface of the heat insulating layer, the adhesion between the heat insulating layer and the second common conductive layer can be enhanced by the first common conductive layer. The first common conductive layer can reduce chipping of the laminated film, and can stabilize the production quality and the production yield.

Further, since the low-resistance third common conductive layer made of a Cu layer having a small electric resistance is arranged adjacent to the heating resistor array, the voltage drop can be significantly reduced. It is possible to realize high printing quality without variation in printing density, and furthermore, since the third common conductive layer is made of low-resistance Cu, the pattern area of the third common conductive layer with respect to the substrate area Can be significantly reduced, and the probability of occurrence of insulation failure between layers due to formation defects (holes or protrusions) in the heat insulating layer or interlayer insulating layer can be significantly reduced.

Further, since the second common conductive layer made of Cr is provided immediately below the heat generating resistor, the heat generation peak temperature of the heat generating resistor can be increased, and the printing thermal efficiency can be significantly improved. be able to.

According to a third aspect of the present invention, in the first or second aspect, the thickness of the first common conductive layer is set to about 0.5.
1 μm, the thickness of the second common conductive layer is about 0.1 μm, the thickness of the third common conductive layer is 0.1 to 0.5 μm, the thickness of the fourth common conductive layer is about 0.1 μm, The film thickness of the fifth common conductive layer is about 1 μm.

According to the third aspect of the present invention, the above-described functions and effects can be obtained by forming each common conductive layer to have the above-mentioned film thickness.

According to a fourth aspect of the present invention, at least a heat insulating layer, a common conductive layer, an interlayer insulating layer having a contact hole, a plurality of heating resistors, and a plurality of heating resistors are connected to the upper surface of the heat dissipation substrate. A thermal head in which a common electrode for electrically connecting the common conductive layer and the heating resistor through the individual electrode and the contact hole is laminated, wherein the common conductive layer is made of Ta cermet. 1 common conductive layer, second common conductive layer made of Cr, T
The third common conductive layer made of a cermet, the fourth common conductive layer made of Cr, and the fifth common conductive layer made of Ta cermet are sequentially formed into five layers.

According to the fourth aspect of the present invention, Ta
Since the first common conductive layer and the third common conductive layer made of cermet and functioning as an adhesive layer are interposed by continuous film formation above and below the second common conductive layer made of Cr, the film of the fourth common conductive layer is formed. Even if the thickness is increased, contamination at each interface due to continuous film formation can be reduced, and chipping of the laminated film can be reduced due to good adhesiveness of Ta cermet. The yield can be stabilized.

Further, of the common conductive layers, the first common conductive layer and the fourth common conductive layer are not separately formed, and the first common conductive layer made of Ta cermet having excellent adhesiveness and the fourth common conductive layer are not formed. Since the third common conductive layer, the second common conductive layer made of Cr, and the fourth common conductive layer are alternately laminated, each common conductive layer can be continuously formed in a vacuum state. Adhesion between the four common conductive layers can be significantly increased, and manufacturing variations can be significantly reduced. In addition, since the selection range of the film thickness of the fourth common conductive layer can be widened and the electric resistance of the fourth common conductive layer can be reduced, the voltage drop can be significantly reduced, and the variation in print density can be reduced. No high printing quality can be realized.

Further, since the second common conductive layer made of Cr is provided, when the heating resistor generates heat, heat loss due to heat radiation from the second common conductive layer can be reduced. The heat generation peak temperature of the heat generating resistor can be increased, and as a result, the printing thermal efficiency can be significantly improved.

According to a fifth aspect of the present invention, in the fourth aspect, the common conductive layer is formed by laminating the lowermost first common conductive layer over the entire surface of the heat insulating layer. On the third common conductive layer, a second common conductive layer and a third common conductive layer are stacked from immediately below the heating resistor to near the end of the heat dissipation board. A fourth common conductive layer is formed on the individual electrode side. Wherein the fifth common conductive layer is formed by laminating in the vicinity of the row of heating resistors, and by laminating the fifth common conductive layer on the entire surface of the heat dissipation substrate on the upper surface of each common conductive layer.

According to the fifth aspect of the present invention, Ta
Since the first common conductive layer and the third common conductive layer made of cermet and functioning as an adhesive layer are laminated on and under the second common conductive layer made of Cr, the fourth common conductive layer is formed to be thick. In this case, contamination of each interface due to continuous film formation can be reduced, and Ta
With good adhesiveness of the cermet, chipping of the laminated film can be reduced, and the production quality and the production yield can be stabilized.

Further, among the respective common conductive layers, the first common conductive layer to the fourth common conductive layer are not separately formed, and the first common conductive layer made of Ta cermet having excellent adhesiveness and the fourth common conductive layer are not formed. Since the third common conductive layer, the second common conductive layer made of Cr, and the fourth common conductive layer are alternately laminated, each common conductive layer can be continuously formed in a vacuum state. Adhesion between the four common conductive layers can be significantly increased, and manufacturing variations can be significantly reduced. In addition, since the selection range of the film thickness of the fourth common conductive layer can be widened and the electric resistance of the fourth common conductive layer can be reduced, the voltage drop can be significantly reduced, and the variation in print density can be reduced. No high printing quality can be realized.

Further, since the second common conductive layer made of Cr is provided directly below the heating resistor, when the heating resistor generates heat, heat is generated by heat radiation from the second common conductive layer. The loss can be reduced, and the heat generation peak temperature of the heat generation resistor can be increased, and as a result, the printing thermal efficiency can be significantly improved.

According to a sixth aspect of the present invention, in the fourth or fifth aspect, the thickness of the first common conductive layer is set to about 0.5.
1 μm, the thickness of the second common conductive layer is about 0.1 μm, the thickness of the third common conductive layer is 0.1 μm, the thickness of the fourth common conductive layer is about 1 μm, and the fifth common conductive layer is Is characterized by having a thickness of about 1 μm.

According to the sixth aspect of the present invention, by forming each common conductive layer to the above-mentioned film thickness, the above-mentioned functions and effects can be obtained.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the interlayer insulating layer is formed by a plurality of layers, and the lowermost first interlayer insulating layer is formed by the fifth common layer. It is characterized by being formed by a surface oxide film of a conductive layer.

According to the seventh aspect of the present invention, since the first interlayer insulating layer, which is the lowermost layer, is formed by the surface oxide film of the fifth common conductive layer, the surface of the fifth common conductive layer is formed. Can be reliably insulated, and occurrence of a conduction failure such as a short circuit in a use state can be reliably prevented.

According to an eighth aspect of the present invention, in the method of the seventh aspect, the thickness of the portion of the fifth common conductive layer located near the outer peripheral portion of the heat dissipation substrate is thinned and subjected to an oxidation treatment. The fifth common conductive layer and the first common conductive layer are made into insulators to form the first interlayer insulating layer.

According to the eighth aspect of the present invention, the fifth aspect
The thickness of the portion of the common conductive layer located on the outer peripheral portion of the heat dissipation substrate is processed to be thin and oxidized to form the first interlayer insulating layer. Of the common conductive layer exposed on the end face of the heat dissipation substrate when the thermal head block is formed in the final step,
It is possible to reliably prevent the occurrence of a conduction failure such as a short circuit in a use state.

According to a ninth aspect of the present invention, there is provided a thermal head manufacturing method, wherein at least a heat insulating layer, a common conductive layer, an interlayer insulating layer having a contact hole, a plurality of heating resistors, A method for manufacturing a thermal head in which individual electrodes connected to each of the heating resistors and a common electrode for electrically connecting the common conductive layer and the heating resistor via the contact hole are sequentially stacked, The first surface made of Ta cermet
Forming a four-layered common conductive layer in which a common conductive layer, a second common conductive layer made of Cr, a third common conductive layer made of Cu, and a fourth common conductive layer made of Cr are sequentially stacked; Patterning a common conductive layer and a fourth common conductive layer to form a strip at a position adjacent to the heating resistor row; and patterning the second common conductive layer located near an outer peripheral portion of the heat dissipation substrate. And a fifth step made of Ta cermet on the entire surface of the heat dissipation substrate.
Stacking a common conductive layer and an oxidation-resistant mask layer, forming a pattern of the oxidation-resistant mask layer at a position where a contact hole is provided, and forming the fifth common conductive layer near an outer peripheral portion of the heat dissipation substrate. Forming a first interlayer insulating layer composed of a surface oxide film generated by the oxidizing process, and oxidizing the entire surface of the fifth common conductive layer; Removing a mask layer, laminating a second interlayer insulating layer made of insulating ceramic on the first interlayer insulating layer, and processing a contact hole in the second interlayer insulating layer. It is a feature.

According to the ninth aspect of the present invention, Ta
A first common conductive layer made of cermet or the like is provided with a heat insulating layer and a second common conductive layer.
Since the first common conductive layer functions as an adhesive layer for further stabilizing the adhesion to the common conductive layer, chipping of the laminated film can be reduced by the first common conductive layer, and the production quality and the production yield can be reduced. Stabilization can be achieved.

Further, since the third common conductive layer is made of Cu having a small electric resistance, a voltage drop when a voltage is applied to each heating resistor can be significantly reduced, and variations in print density can be achieved. It is possible to realize high printing quality without any defects, furthermore, it is possible to remarkably reduce the pattern area of the third common conductive layer with respect to the substrate area, and to cause formation defects (holes and projections) of the heat insulating layer and the interlayer insulating layer. The probability of occurrence of insulation failure between layers can be significantly reduced.

Further, by disposing the second common conductive layer made of Cr, when the heat generating resistor generates heat, heat loss due to heat radiation from the second common conductive layer can be reduced. Can be increased, and as a result, the printing thermal efficiency can be significantly improved.

Further, the third common conductive layer made of Cu is
Since it is sandwiched between the second common conductive layer and the fourth common conductive layer made of r, even if a high-temperature heat treatment step is performed, a decrease in adhesion due to oxidation and diffusion of the Cu layer is reliably prevented. Therefore, the production quality and the production yield can be stabilized.

According to a tenth aspect of the present invention, at least a heat insulating layer, a common conductive layer, an interlayer insulating layer having contact holes, a plurality of heating resistors, and a plurality of heating resistors are connected to the upper surface of the heat dissipation substrate. A method for manufacturing a thermal head in which a common electrode for electrically connecting the common conductive layer and the heating resistor via an individual electrode and the contact hole is sequentially laminated, wherein a top surface of the heat insulating layer is formed from Ta cermet. Forming a four-layered common conductive layer in which a first common conductive layer made of Cr, a second common conductive layer made of Cr, a third common conductive layer made of Ta cermet, and a fourth common conductive layer made of Cr are sequentially stacked; Patterning the fourth common conductive layer to form a strip at a position adjacent to the heating resistor row; and forming the second common conductive layer near an outer peripheral portion of the heat dissipation substrate. And a step of the third common conductive layer is removed by patterning, Ta on the entire surface of the radiating board
Stacking a fifth common conductive layer made of cermet and an oxidation-resistant mask layer;
A step of forming a pattern of the oxidation-resistant mask layer, a step of thinning the thickness of the fifth common conductive layer located near the outer peripheral portion of the heat dissipation substrate, and oxidizing the entire surface of the fifth common conductive layer. Processing, forming a first interlayer insulating layer made of a surface oxide film generated by the oxidation process, removing the oxidation-resistant mask layer, and forming a first interlayer insulating layer on the first interlayer insulating layer made of an insulating ceramic. The method includes a step of laminating two interlayer insulating layers and a step of processing a contact hole in the second interlayer insulating layer.

According to the tenth aspect of the present invention, T
Since the first common conductive layer and the third common conductive layer, which are made of cermet and function as adhesive layers, are interposed by continuous film formation above and below the second common conductive layer made of Cr, the fourth common conductive layer Even if the film is formed to be thick, it is possible to reduce the contamination of each interface due to continuous film formation, and it is possible to reduce chipping of the laminated film due to the good adhesiveness of Ta cermet, thereby improving production quality and The production yield can be stabilized.

Further, of the common conductive layers, the first common conductive layer to the fourth common conductive layer are not separately formed, and the first common conductive layer made of Ta cermet having excellent adhesiveness and the fourth common conductive layer are not formed. Since the third common conductive layer, the second common conductive layer made of Cr, and the fourth common conductive layer are alternately laminated, each common conductive layer can be continuously formed in a vacuum state. Adhesion between the four common conductive layers can be significantly increased, and manufacturing variations can be significantly reduced. In addition, since the selection range of the film thickness of the fourth common conductive layer can be widened and the electric resistance of the fourth common conductive layer can be reduced, the voltage drop can be significantly reduced, and the variation in print density can be reduced. No high printing quality can be realized.

Further, since the second common conductive layer made of Cr is provided, when the heating resistor generates heat, heat loss due to heat radiation from the second common conductive layer can be reduced. The heat generation peak temperature of the heat generating resistor can be increased, and as a result, the printing thermal efficiency can be significantly improved.

[0050]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG.

FIG. 1 shows an embodiment of a thermal head according to the present invention, in which a heat insulating layer 2 made of glass or the like is formed on the entire surface of a heat radiating substrate 1 made of an insulating ceramic such as alumina. In the vicinity of one end of the heat dissipation substrate 1, a convex portion 3 of the heat insulating layer 2 is formed by means such as etching.

On the upper surface of the heat insulating layer 2, five common conductive layers 4 are formed. That is, the heat insulation layer 2
A first common conductive layer 4a made of Ta cermet or the like and having a thickness of about 0.1 μm is laminated over substantially the entire area of the heat insulating layer 2, and the first common conductive layer 4
The upper surface of a is made of a refractory metal such as Cr
The second common conductive layer 4b having a thickness of m is laminated. On the upper surface of the second common conductive layer 4b and on the side opposite to the one end of the heat dissipation substrate 1 with respect to the convex portion 3, a thickness of about 0.3 μm made of low-resistance metal such as Cu is used. The third common conductive layer 4c is laminated in a belt-like pattern, and the upper surface of the third common conductive layer 4c is
And a fourth common conductive layer 4d having a thickness of about 0.1 μm. In this case, the first common conductive layer 4a made of Ta cermet or the like is an adhesive layer for further stabilizing the adhesion between the heat insulating layer 2 and the second common conductive layer 4b made of Cr or the like. The second common conductive layer 4b and the fourth common conductive layer 4d made of Cr or the like are adhesion layers for preventing oxidation and diffusion of Cu of the third common conductive layer 4c and stabilizing the adhesion.

The four common conductive layers 4a, 4b, 4
On the upper surfaces of c and 4d, about 1 μm made of Ta cermet or the like is used.
A fifth common conductive layer 4e having a thickness of m is laminated, and a first interlayer insulating layer 5a made of an insulating oxide ceramic or the like is formed on an upper surface of the fifth common conductive layer 4e. There is a portion where the first interlayer insulating layer 5a is not formed in a part of the heat dissipation board 1 on the end side from the convex portion 3;
This portion is a contact hole 6.

Then, on the upper surface of the first interlayer insulating layer 5a,
A second interlayer insulating layer 5b made of an insulating ceramic such as SiO ₂ and having a thickness of about 2 μm is laminated. Even in this case, the second interlayer insulating layer 5b is located at a position corresponding to the contact hole 6. Is not formed.

On the upper surface of the second interlayer insulating layer 5b and on both sides of the convex portion 3, a lower common electrode 7a and a lower individual electrode 8a made of a refractory metal such as Mo, Cr and W are formed. On the upper surfaces of the lower common electrode 7a and the lower individual electrode 8a, a heating resistor 9 made of Ta cermet or the like is formed. Further, on the upper surface of the heating resistor 9 and on both sides of the convex portion 3, Al,
Upper common electrode 7b and upper individual electrode 8 made of Cu or the like
On the upper surfaces of the heating resistor 9, the upper common electrode 7b and the upper individual electrode 8b, a protective layer 10 made of an oxidation-resistant hard ceramic such as sialon for preventing abrasion and oxidation is provided. It is laminated. The upper common electrode 7b does not need to be formed because of the presence of the lower common electrode 7a.

Next, a method of manufacturing a thermal head according to the present invention will be described with reference to a flowchart of a manufacturing process of a multilayer wiring board shown in FIG.

First, a heat insulating layer 2 made of glass or the like is formed on the entire upper surface of a heat radiating substrate 1 made of alumina or the like, and the heat insulating layer 2 at the end of the heat radiating substrate 1 is etched or the like to form a convex portion 3. (Step 1).

Subsequently, a first common conductive layer 4 having a thickness of about 0.1 μm is formed on the upper surface of the heat insulating layer 2 by Ta cermet or the like.
a, a second common conductive layer 4b with a thickness of about 0.1 μm made of Cr or the like, a third common conductive layer 4c with a thickness of about 0.3 μm made of Cu or the like, and a thickness of about 0.3 μm made of Cr or the like. 1 μm fourth
The common conductive layer 4d is continuously laminated (Step 2).

The common conductive layers 4a, 4b,
Among the 4c and 4d, the third common conductive layer 4c and the fourth common conductive layer 4d are formed by photolithography technology on the portion of the heat-insulating layer 2 opposite to the one end of the heat-radiating substrate 1 with respect to the convex portion 3 of the heat insulating layer 2. The second common conductive layer 4b is formed in a strip-shaped pattern so as to be adjacent to the body 9 rows, and the third common conductive layer 4c and the fourth common conductive layer 4d are formed by photolithography.
Is formed into a band-shaped pattern so as to extend from the outer shape pattern to the vicinity of the end of the heat radiation substrate 1 (step 3).

The common conductive layers 4a, 4b, 4
On the upper surfaces of c and 4d, a fifth common conductive layer 4e made of a Ta cermet layer and having a thickness of about 1 μm is laminated. Thereafter, the upper surface of the fifth common conductive layer 4e, after the film thickness made of oxidation-resistant ceramic or oxidation resistant alloy of ₂ such as SiO ₂ or MoSi is laminated anti-oxidation mask layer of about 0.2 [mu] m, the acid Etching the mask layer to form the fifth common conductive layer 4e.
Is formed so that the oxidation-resistant mask layer remains only at the position where the contact hole 6 is formed (step 4).

Next, the fifth heat radiation substrate 1
Half etching is performed near the outer periphery of the common conductive layer 4e, and the common conductive layer 4e is thinned so as to have a thickness of about 以下 or less. Thereafter, the entire surface of the fifth common conductive layer 4e is heated to about 700 ° C.
The thermal oxidation treatment is performed at the temperature of
About 50% of the film thickness (1 μm) of the fifth common conductive layer 4e is made of insulating ceramic, and near the outer peripheral portion where the film thickness is small, 100% of the film thickness is made of insulating ceramic. Then, a first interlayer insulating layer 5a is formed from the insulating ceramic (step 5).

After forming the first interlayer insulating layer 5a, the oxidation-resistant mask layer is removed by etching to expose the contact hole 6 on the surface of the fifth common conductive layer 4e. Then, SiO 2 is formed on the upper surface of the first interlayer insulating layer 5a.
_Second interlayer insulating layer 5 made of ₂ etc. and having a thickness of about 2 μm
b, and the second interlayer insulating layer 5 is formed by photolithography.
By forming the contact hole 6 in b, the multilayer wiring board of the present invention is completed (step 6).

The lower common electrode 7a made of a high melting point metal such as Mo, Cr, W, etc. is formed on the multilayer wiring board completed by the above steps by the same manufacturing steps as the conventional thermal head.
The lower-layer individual electrode 8a is laminated on both sides of the convex portion 3, and a heating resistor 9 made of Ta cermet or the like is laminated on the upper surfaces of the lower-layer common electrode 7a and the lower-layer individual electrode 8a. Further, the heating resistor 9
Al, Cu on both sides of the convex portion 3
The upper-layer common electrode 7b and the upper-layer individual electrode 8b are laminated, and the heating resistor 9 and the upper-layer common electrode 7b are stacked.
A protective layer 10 made of an oxidation-resistant hard ceramic such as sialon is laminated on the upper surface of the upper electrode 8b and the upper individual electrode 8b to prevent abrasion and oxidation. Thereafter, the substrate is cut by dicing to produce a multilayer wiring type thermal head having the common electrodes 7a and 7b with real edges as shown in FIG.

In the present embodiment, by energizing the upper individual electrode 8b based on desired print information, the desired heating resistor 9 is energized via the lower individual electrode 8a. The current from the heating resistor 9 passes through the upper-layer common electrode 7b and the lower-layer common electrode 7a, and passes through the contact holes 6 to the respective common conductive layers 4a, 4a.
B, 4c, 4d, and 4e are energized to be conducted to the outside.

Therefore, in this embodiment, Ta
The first common conductive layer 4a made of cermet or the like is used as the heat insulating layer 2
Function as an adhesive layer for further stabilizing the adhesiveness between the first common conductive layer 4b and the second common conductive layer 4b. When processing is performed, chipping of the laminated film can be reduced, and the production quality and the production yield can be stabilized.

Further, the second common conductive layer 4b made of opaque and thin Cr is disposed immediately below the heating resistor 9 so that the second common conductive layer 4b is formed when the heating resistor 9 generates heat. The heat loss due to the heat radiation from the layer 4b can be reduced, and the heat generation peak temperature of the heat generating resistor 9 can be increased. As a result, the printing thermal efficiency can be significantly improved.

Further, adjacent to the row of heating resistors 9, a third low-resistance common conductive layer 4 made of a Cu layer having a low electric resistance is provided.
Since c is provided, a voltage drop when a voltage is applied to each heating resistor 9 can be reduced to a negligible level, so that high printing quality without variation in printing density can be realized. Further, since the third common conductive layer 4c is formed of low-resistance Cu, the pattern area of the third common conductive layer 4c can be significantly reduced with respect to the substrate area. The probability of occurrence of insulation failure between layers due to formation defects (holes or protrusions) of layers 5a and 5b can be significantly reduced.

Further, since the third common conductive layer 4c made of Cu is sandwiched between the second common conductive layer 4b and the fourth common conductive layer 4d made of Cr, even if a high-temperature heat treatment step is performed. In addition, it is possible to reliably prevent a decrease in adhesion due to oxidation or diffusion of the Cu layer, and to stabilize manufacturing quality and manufacturing yield.

The fifth common conductive layer 4e and the first common conductive layer 4a in the vicinity of the outer peripheral portion of the heat radiating substrate 1 are made of insulating ceramic for 100% of the film thickness. The common conductive layers 4a, 4b, 4c, 4d, 4
e can be electrically insulated, and the occurrence of insulation failure such as a short circuit in use can be reliably prevented.

FIG. 3 shows another embodiment of the thermal head according to the present invention. A heat insulating layer 2 made of glass or the like is formed on the entire surface of a heat radiating substrate 1 made of an insulating ceramic such as alumina. In the vicinity of one end of the heat dissipation substrate 1, a convex portion 3 of the heat insulating layer 2 is formed by means such as etching.

On the upper surface of the heat insulating layer 2, five common conductive layers 4 are formed. That is, the heat insulation layer 2
A first common conductive layer 4a made of Ta cermet and having a thickness of about 0.1 μm is laminated on substantially the entire area of the heat insulating layer 2 on the upper surface of the first common conductive layer 4a.
The upper surface is made of high melting point metal such as Cr
A second common conductive layer 4b having a thickness of
A third common conductive layer 4c made of Ta cermet or the like and having a thickness of about 0.1 μm is laminated on the upper surface of the second common conductive layer 4b. A fourth common conductive layer 4d made of a refractory metal such as Cr and having a thickness of about 1 μm is laminated in a strip-shaped pattern on a portion opposite to one end of the heat dissipation substrate 1 with respect to the convex portion 3. I have. In this case, the first made of Ta cermet or the like is used.
The common conductive layer 4a and the third common conductive layer 4c prevent the stress separation of the second common conductive layer 4b and the fourth common conductive layer 4d, and the heat insulating layer 2 and the second common conductive layer 4b made of Cr or the like. It serves as an adhesive layer for further stabilizing the interlayer adhesion with the fourth common conductive layer 4d, and also serves as an etchant-resistant layer when the second common conductive layer 4b and the fourth common conductive layer 4d are etched. Things.

Each of these four common conductive layers 4a, 4b, 4
On the upper surfaces of c and 4d, about 1 μm made of Ta cermet or the like is used.
A fifth common conductive layer 4e having a thickness of m is laminated, and a first interlayer insulating layer 5a made of an insulating oxide ceramic or the like is formed on an upper surface of the fifth common conductive layer 4e. There is a portion where the first interlayer insulating layer 5a is not formed in a part of the heat dissipation board 1 on the end side from the convex portion 3;
This portion is a contact hole 6.

Then, on the upper surface of the first interlayer insulating layer 5a,
A second interlayer insulating layer 5b made of an insulating ceramic such as SiO ₂ and having a thickness of about 2 μm is laminated. Even in this case, the second interlayer insulating layer 5b is located at a position corresponding to the contact hole 6. Is not formed.

On the upper surface of the second interlayer insulating layer 5b and on both sides of the convex portion 3, a lower common electrode 7a and a lower individual electrode 8a made of a refractory metal such as Mo, Cr and W are formed. On the upper surfaces of the lower common electrode 7a and the lower individual electrode 8a, a heating resistor 9 made of Ta cermet or the like is formed. Further, on the upper surface of the heating resistor 9 and on both sides of the convex portion 3, Al,
Upper common electrode 7b and upper individual electrode 8 made of Cu or the like
On the upper surfaces of the heating resistor 9, the upper common electrode 7b and the upper individual electrode 8b, a protective layer 10 made of an oxidation-resistant hard ceramic such as sialon for preventing abrasion and oxidation is provided. It is laminated. The upper common electrode 7b does not need to be formed because of the presence of the lower common electrode 7a.

Next, a method of manufacturing a thermal head according to the present invention will be described with reference to a flowchart of a manufacturing process of a multilayer wiring board shown in FIG.

First, a heat insulating layer 2 made of glass or the like is formed over the entire upper surface of a heat radiating substrate 1 made of alumina or the like, and the heat insulating layer 2 at the end of the heat radiating substrate 1 is etched or the like to form the convex portion 3. (Step 1).

Subsequently, the first common conductive layer 4 having a thickness of about 0.1 μm is formed on the heat insulating layer 2 by using Ta cermet or the like.
a, a second common conductive layer 4b having a thickness of about 0.1 μm made of Cr or the like, and a thickness of about 0.1 μm made of Ta cermet or the like.
The third common conductive layer 4c and a film thickness of about 1 μm
The fourth common conductive layer 4d is continuously laminated (step 2).

The common conductive layers 4a, 4b,
Of the 4c and 4d, the fourth common conductive layer 4d is formed by photolithography so as to be adjacent to the row of the heating resistors 9 at a portion opposite to one end of the heat dissipation substrate 1 with respect to the convex portion 3 of the heat insulating layer 2. To form a band-shaped pattern (step 3).

Subsequently, the third common conductive layer 4c and the second common conductive layer 4b are separated from the outer shape pattern of the fourth common conductive layer 4d by a photolithographic etching technique.
Is formed in a belt-like pattern so as to extend to the vicinity of the end of the step (step 4).

The common conductive layers 4a, 4b, 4
On the upper surfaces of c and 4d, a fifth common conductive layer 4e made of a Ta cermet layer and having a thickness of about 1 μm is laminated. Thereafter, the upper surface of the fifth common conductive layer 4e, after the film thickness made of oxidation-resistant ceramic or oxidation resistant alloy of ₂ such as SiO ₂ or MoSi is laminated anti-oxidation mask layer of about 0.2 [mu] m, the acid Etching the mask layer to form the fifth common conductive layer 4e.
Is formed so that the oxidation-resistant mask layer remains only at the position where the contact hole 6 is formed. Next, half etching is applied to the vicinity of the outer peripheral portion of the fifth common conductive layer 4e laminated on the entire surface of the heat dissipation substrate 1, and the fifth common conductive layer 4e is thinned so as to have a thickness of about 以下 or less (step 5).

Thereafter, the entire surface of the fifth common conductive layer 4e is subjected to a thermal oxidation treatment at a temperature of about 700 ° C., and this thermal oxidation treatment causes the thickness of the fifth common conductive layer 4e to be about 50 μm (1 μm).
% Is insulative ceramic, and 100% of the film thickness is insulative ceramic near the outer peripheral portion where the film thickness is small. Then, a first interlayer insulating layer 5a is formed from this insulating ceramic (step 6).

After forming the first interlayer insulating layer 5a, the oxidation-resistant mask layer is removed by etching, and a conductive contact hole 6 is formed in the surface of the fifth common conductive layer 4e.
To expose. Then, a second interlayer insulating layer 5b made of SiO ₂ or the like and having a thickness of about 2 μm is laminated on the upper surface of the first interlayer insulating layer 5a (Step 7).

Then, a contact hole 6 is formed in the second interlayer insulating layer 5b by photolithography, thereby completing the multilayer wiring board of the present invention (step 8).

The lower common electrode 7a made of a high melting point metal such as Mo, Cr, or W is formed on the multilayer wiring board completed by the above steps by the same manufacturing steps as those of the conventional thermal head.
The lower-layer individual electrode 8a is laminated on both sides of the convex portion 3, and a heating resistor 9 made of Ta cermet or the like is laminated on the upper surfaces of the lower-layer common electrode 7a and the lower-layer individual electrode 8a. Further, the heating resistor 9
Al, Cu on both sides of the convex portion 3
The upper-layer common electrode 7b and the upper-layer individual electrode 8b are laminated, and the heating resistor 9 and the upper-layer common electrode 7b are stacked.
A protective layer 10 made of an oxidation-resistant hard ceramic such as sialon is laminated on the upper surface of the upper electrode 8b and the upper individual electrode 8b to prevent abrasion and oxidation. Thereafter, the wafer is cut by dicing to produce a multilayered thermal head having real edges as shown in FIG.

Therefore, in the present embodiment, as in the previous embodiment, the first common conductive layer 4a and the third common conductive layer 4c made of Ta cermet and functioning as an adhesive layer are replaced with the second common conductive layer made of Cr. Since the fourth common conductive layer 4d is formed to have a large thickness because it is interposed by continuous film formation above and below 4b, contamination of each interface due to continuous film formation can be reduced. , The good adhesion of Ta cermet, it is possible to reduce the chipping of the laminated film when dicing is performed in the final step of the real-edged thermal head, and to stabilize the production quality and production yield. Can be.

In addition, since the four layers of the first common conductive layer 4a to the fourth common conductive layer 4d are not individually formed, T
a The first common conductive layer 4a and the third common conductive layer 4c made of cermet and the second common conductive layer 4b and the fourth common conductive layer 4d made of Cr are formed alternately and continuously in a vacuum state. So that the above 4
Adhesion between the common conductive layers 4a, 4b, 4c, and 4d of the layers can be significantly increased, and manufacturing variations can be significantly reduced. In addition, since the selection range of the film thickness of the fourth common conductive layer 4d can be expanded, the electric resistance of the fourth common conductive layer 4d can be reduced, and the voltage when applying a voltage to each heating resistor 9 can be reduced. Since the drop can be made so small as to be negligible, high print quality without variation in print density can be realized.

The second common conductive layer 4b made of opaque and thin Cr is disposed immediately below the heating resistor 9 so that when the heating resistor 9 generates heat, the second common conductive layer 4b is formed. The heat loss due to the heat radiation from the layer 4b can be reduced, and the heat generation peak temperature of the heat generating resistor 9 can be increased. As a result, the printing thermal efficiency can be significantly improved.

Further, the fifth common conductive layer 4e and the first common conductive layer 4a in the vicinity of the outer peripheral portion of the heat radiating substrate 1 are made of insulating ceramic for 100% of the film thickness. Heat sink 1
Of the common conductive layers 4a, 4b, 4c, 4d,
4e can be electrically insulated, and the occurrence of insulation failure such as a short circuit in use can be reliably prevented.

The present invention is not limited to the above-described embodiment, and various changes can be made as needed.

[0090]

As described above, in the thermal head according to the first aspect of the present invention, the first common conductive layer can reduce the chipping of the laminated film and stabilize the production quality and the production yield. be able to. Further, the voltage drop is significantly reduced by the third common conductive layer, and high printing quality without variation in print density can be realized. Further, the pattern area of the third common conductive layer is significantly reduced with respect to the substrate area. Therefore, the probability of occurrence of insulation failure between layers due to formation defects of the heat insulation layer and the interlayer insulation layer can be significantly reduced. Further, the heat generation peak temperature of the heat generating resistor can be increased by the second common conductive layer, and as a result, the printing thermal efficiency can be significantly improved.
Further, by sandwiching the third common conductive layer between the second common conductive layer and the fourth common conductive layer, even when a heat treatment process at a high temperature is performed, a decrease in adhesion due to oxidation and diffusion of the Cu layer is ensured. Therefore, the production quality and the production yield can be stabilized.

According to the second aspect of the present invention, by stacking the first common conductive layer on the entire surface of the heat insulating layer, it is possible to reduce the chipping of the stacked film and to stabilize the manufacturing quality and the manufacturing yield. Can be. Further, by arranging the third common conductive layer adjacent to the heating resistor array, a voltage drop can be significantly reduced, and high printing quality without variation in printing density can be realized. The pattern area of the third common conductive layer can be significantly reduced with respect to the substrate area, and the probability of occurrence of insulation failure between layers due to formation defects of the heat insulating layer and the interlayer insulating layer can be significantly reduced. In addition, by disposing the second common conductive layer immediately below the heating resistor, the heat generation peak temperature of the heating resistor can be increased, and the printing thermal efficiency can be significantly improved.

According to the third aspect of the present invention, the above-mentioned functions and effects can be obtained by forming each common conductive layer to a predetermined thickness.

According to a fourth aspect of the present invention, the first common conductive layer and the third common conductive layer are disposed above and below the second common conductive layer, so that the thickness of the fourth common conductive layer is increased. Even if it does in this way, the contamination of each interface by continuous film formation can be reduced, chipping of the laminated film can be reduced, and the production quality and the production yield can be stabilized. Further, since the first common conductive layer and the third common conductive layer and the second common conductive layer and the fourth common conductive layer are alternately laminated, the respective common conductive layers are continuously formed in a vacuum state. Thus, the adhesion between the four common conductive layers can be remarkably increased, and the manufacturing variation can be significantly reduced. And the fourth
The selection range of the film thickness of the common conductive layer can be widened, the voltage drop can be remarkably reduced, and high printing quality without variation in printing density can be realized. In addition, by providing the second common conductive layer, the heat generation peak temperature of the heat generating resistor can be increased, and as a result, the printing thermal efficiency can be significantly improved.

According to a fifth aspect of the present invention, the first common conductive layer and the third common conductive layer are stacked on and under the second common conductive layer, so that the fourth common conductive layer is formed to have a large thickness. In this case, contamination at each interface due to continuous film formation can be reduced, chipping of the laminated film can be reduced, and the production quality and the production yield can be stabilized. Further, since the first common conductive layer and the third common conductive layer and the second common conductive layer and the fourth common conductive layer are alternately laminated, the respective common conductive layers are continuously formed in a vacuum state. Thus, the adhesion between the four common conductive layers can be remarkably increased, and the manufacturing variation can be significantly reduced. In addition, the selection range of the film thickness of the fourth common conductive layer can be widened, the voltage drop can be significantly reduced, and high printing quality without variation in printing density can be realized. Also,
By arranging the second common conductive layer immediately below the heating resistor, it is possible to increase the heat generation peak temperature of the heating resistor, and as a result, it is possible to significantly improve the printing thermal efficiency.

According to the invention described in claim 6, the above-mentioned functions and effects can be obtained by forming each common conductive layer to a predetermined thickness.

According to the seventh aspect of the present invention, since the first interlayer insulating layer is formed by the surface oxide film of the fifth common conductive layer, the surface of the fifth common conductive layer can be reliably insulated. It is possible to reliably prevent the occurrence of insulation failure such as a short circuit in use.

[0097] According to the present invention, almost 100% of the thickness of the common conductive layer is insulative ceramic near the outer peripheral portion of the heat radiating substrate. The exposed common conductive layer can be electrically insulated, and the occurrence of insulation failure such as a short circuit in use can be reliably prevented.

In the method of manufacturing a thermal head according to the ninth aspect of the present invention, the first common conductive layer can reduce the chipping of the laminated film, and can stabilize the manufacturing quality and the manufacturing yield. it can. Further, the voltage drop can be significantly reduced by the third common conductive layer,
It is possible to realize high printing quality without variation in printing density, furthermore, it is possible to remarkably reduce the pattern area of the third common conductive layer with respect to the substrate area, and to form defects (holes) in the heat insulating layer and the interlayer insulating layer. And protrusions) can significantly reduce the probability of occurrence of insulation failure between layers. In addition, the second common conductive layer can raise the heat generation peak temperature of the heat generating resistor, and as a result, can significantly improve the printing heat efficiency. Further, the third common conductive layer is
Since it is sandwiched between the common conductive layer and the fourth common conductive layer, even when a high-temperature heat treatment step is performed, a decrease in adhesion due to oxidation and diffusion of the Cu layer can be reliably prevented, and manufacturing Quality and production yield can be stabilized.

According to a tenth aspect of the present invention, the first common conductive layer and the third common conductive layer are disposed above and below the second common conductive layer, so that the fourth common conductive layer is formed to be thick. Even if it does in this way, the contamination of each interface by continuous film formation can be reduced, chipping of the laminated film can be reduced, and the production quality and the production yield can be stabilized. Further, since the first common conductive layer and the third common conductive layer and the second common conductive layer and the fourth common conductive layer are alternately laminated, the respective common conductive layers are continuously formed in a vacuum state. Thus, the adhesion between the four common conductive layers can be remarkably increased, and the manufacturing variation can be significantly reduced. In addition, the selection range of the film thickness of the fourth common conductive layer can be widened, the voltage drop can be significantly reduced, and high printing quality without variation in printing density can be realized. Also,
With the second common conductive layer, the heat generation peak temperature of the heat generating resistor can be increased, and as a result, there is an effect that the printing thermal efficiency can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of a thermal head according to the present invention.

FIG. 2 is a flowchart showing one embodiment of a method of manufacturing a thermal head according to the present invention.

FIG. 3 is a partial cross-sectional view showing another embodiment of the thermal head according to the present invention.

FIG. 4 is a flowchart showing another embodiment of the method for manufacturing a thermal head according to the present invention.

FIG. 5 is a partial cross-sectional view showing a conventional thermal head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat dissipation board 2 Heat insulation layer 3 Convex part 4 Common conductive layer 5 Interlayer insulation layer 6 Contact hole 7 Common electrode 8 Individual electrode 9 Heating resistor 10 Protection layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C065 GB01 JD05 JD09 JD12 JD13 JD15 JE03 JE04 JE06 JE08 JE13 JE17 JH03 JH04 JH07 JH10 JH11 JH14

Claims (10)

[Claims] At least a heat insulating layer is provided on an upper surface of a heat dissipation substrate.
A common conductive layer, an interlayer insulating layer having a contact hole, a plurality of heating resistors, individual electrodes connected to each of the heating resistors, and the common conductive layer and the heating resistor are electrically connected via the contact holes. Wherein the common conductive layer is a first common conductive layer made of Ta cermet;
The second common conductive layer made of r, the third common conductive layer made of Cu, the fourth common conductive layer made of Cr, and the fifth common conductive layer made of Ta cermet are sequentially laminated to form five layers. Thermal head. 2. The method according to claim 1, wherein the common conductive layer is formed by laminating the first common conductive layer, which is the lowermost layer, on the entire surface of the heat insulating layer.
A second common conductive layer is stacked on the common conductive layer from immediately below the heating resistor to near the end of the heat dissipation substrate, and a third common conductive layer and a fourth common conductive layer are formed on the second common conductive layer. The fifth common conductive layer is laminated on the individual electrode side and in the vicinity of the row of heating resistors, and a fifth common conductive layer is formed on the entire surface of the heat dissipation substrate on the upper surface of each common conductive layer. Item 2. The thermal head according to item 1. 3. The thickness of the first common conductive layer is about 0.1 μm.
m, the thickness of the second common conductive layer is about 0.1 μm, the thickness of the third common conductive layer is 0.1 to 0.5 μm, the thickness of the fourth common conductive layer is about 0.1 μm, 3. The thermal head according to claim 1, wherein the thickness of the fifth common conductive layer is about 1 [mu] m. 4. At least a heat insulating layer on an upper surface of the heat dissipation substrate.
A common conductive layer, an interlayer insulating layer having a contact hole, a plurality of heating resistors, individual electrodes connected to each of the heating resistors, and the common conductive layer and the heating resistor are electrically connected via the contact holes. Wherein the common conductive layer is a first common conductive layer made of Ta cermet;
r, a third common conductive layer made of Ta cermet, a fourth common conductive layer made of Cr, and a fifth common conductive layer made of Ta cermet. Characteristic thermal head. 5. A method according to claim 1, wherein said common conductive layer is formed by laminating said first common conductive layer as a lowermost layer on the entire surface of said heat insulating layer.
A second common conductive layer and a third common conductive layer are stacked on the common conductive layer from immediately below the heating resistor to near the end of the heat dissipation board, and a fourth common conductive layer is formed on the third common conductive layer. The fifth common conductive layer is laminated on the individual electrode side and in the vicinity of the row of heating resistors, and a fifth common conductive layer is formed on the entire surface of the heat dissipation substrate on the upper surface of each common conductive layer. Item 5. The thermal head according to Item 4. 6. The first common conductive layer has a thickness of about 0.1 μm.
m, the thickness of the second common conductive layer is about 0.1 μm, the thickness of the third common conductive layer is 0.1 μm, the thickness of the fourth common conductive layer is about 1 μm, and the fifth common conductive layer is About 1μ
The thermal head according to claim 4, wherein m is set to m. 7. The method according to claim 1, wherein the interlayer insulating layer is formed of a plurality of layers,
2. The device according to claim 1, wherein the first interlayer insulating layer serving as the lowermost layer is formed of a surface oxide film of the fifth common conductive layer.
The thermal head according to any one of claims 1 to 6. 8. The fifth common conductive layer and the first common conductive layer are formed by thinning a portion of the fifth common conductive layer located in the vicinity of an outer peripheral portion of the heat dissipation substrate and performing an oxidation process. 8. The thermal head according to claim 7, wherein the first interlayer insulating layer is formed by converting a layer into an insulator. 9. At least a heat insulating layer on an upper surface of the heat radiation substrate,
A common conductive layer, an interlayer insulating layer having a contact hole, a plurality of heating resistors, individual electrodes connected to each of the heating resistors, and the common conductive layer and the heating resistor are electrically connected via the contact holes. A method for manufacturing a thermal head in which a common electrode connected to a first common conductive layer made of Ta cermet, a second common conductive layer made of Cr, and a third common made of Cu are formed on an upper surface of the heat insulating layer. Forming a four-layered common conductive layer in which a conductive layer and a fourth common conductive layer made of Cr are sequentially stacked; and patterning the third common conductive layer and the fourth common conductive layer to form the heating resistor. Forming a strip at a position adjacent to the row; removing the second common conductive layer located near the outer peripheral portion of the heat dissipation substrate by patterning; a step of laminating a fifth common conductive layer made of cermet and an oxidation-resistant mask layer; a step of forming a pattern of the oxidation-resistant mask layer at a position where a contact hole is provided; Processing the thickness of the fifth common conductive layer to be thinner, and oxidizing the entire surface of the fifth common conductive layer to form a first interlayer insulating layer made of a surface oxide film generated by the oxidizing process. A step of removing the oxidation-resistant mask layer; and a second step of forming an insulating ceramic on the first interlayer insulating layer.
A method for manufacturing a thermal head, comprising: a step of laminating an interlayer insulating layer; and a step of processing a contact hole in the second interlayer insulating layer. 10. At least a heat insulating layer, a common conductive layer, an interlayer insulating layer having contact holes, a plurality of heating resistors, individual electrodes connected to each of these heating resistors, and the contact holes are formed on the upper surface of the heat dissipation substrate. A method for manufacturing a thermal head, wherein a common electrode for electrically connecting the common conductive layer and the heating resistor is sequentially laminated via a first common conductive layer made of Ta cermet on an upper surface of the heat insulating layer. Forming a four-layered common conductive layer formed by sequentially stacking a second common conductive layer made of Cr, a third common conductive layer made of Ta cermet, and a fourth common conductive layer made of Cr; Forming a strip shape at a position adjacent to the heating resistor row; and forming the second common conductive layer and the third common conductive layer located near the outer peripheral portion of the heat dissipation substrate. Removing a fifth common conductive layer made of Ta cermet and an oxidation-resistant mask layer over the entire surface of the heat-dissipating substrate; and providing a pattern of the oxidation-resistant mask layer at a position where a contact hole is provided. Forming a thin film of the fifth common conductive layer located near the outer peripheral portion of the heat dissipation substrate; and oxidizing the entire surface of the fifth common conductive layer. A step of forming a first interlayer insulating layer formed of the generated surface oxide film; a step of removing the oxidation-resistant mask layer; and a second step of forming an insulating ceramic on the first interlayer insulating layer.
A method for manufacturing a thermal head, comprising: a step of laminating an interlayer insulating layer; and a step of processing a contact hole in the second interlayer insulating layer.