JP2000071500A - Substrate for thermal head, and thermal head made up therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate for thermal head that can be manufactured easily with adhesiveness between a base and an insulating layer being satisfactory without requiring burning while being suitable to bending processing, and also to provide a thermal head using the substrate for thermal head. SOLUTION: The substrate is such that has a base 1 selected out of the base 1 made of iron alloy including 5-30% of chromium, the base 1 made of iron alloy including 5-30% of chromium and 7-80% of nickel, the base 1 made of iron alloy including 35-80% of nickel and the base 1 made of aluminum or aluminum alloy including 0-30% of one selected out of groups of Fe, Si, Mg, Cu, Ti and V and an insulating layer 2 in the thickness of 1-40 μm formed on the base 1. A naturally oxidized film 20 is desirable to be formed at the surface of the base 1 while the insulating layer 2 is desirable to be formed by film-forming processing. Furthermore, the shape is desirably to be such that partly protrudes in a beltlike form.

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 substrate for a thermal head suitably used for the thermal head. TECHNICAL FIELD The present invention relates to a thermal head substrate having good performance and suitable for bending, and a thermal head using the same.

[0002]

2. Description of the Related Art In recent years, thermal heads have been used in many applications such as recording units of printers, facsimile machines, word processors and the like. Generally, in a thermal head,
As a material for forming the substrate, Al ₂ having a purity of 90% or more is used.
A ceramic substrate using O ₃ is used. This ceramic substrate has the advantage of being excellent in electrical insulation, but has the disadvantage that mechanical strength such as refractive power and bending strength is weak, and that processing such as bending is difficult. In addition, when forming the ceramic substrate, steps such as an alkali metal removing step of removing an alkali metal component, a firing step of firing at a high temperature, a polishing finishing step of removing undulations, and the like are required, which is troublesome. Was a problem.

In order to solve such a problem, a metal substrate using a metal as a material for forming the substrate has been proposed. Examples of such a metal substrate include an iron alloy, an oxide layer formed of the iron alloy constituent element formed on the main surface of the iron alloy, and a glass layer formed on the oxide layer. (Japanese Patent Publication 6-35184) and a ferritic stainless steel alloy containing iron and chromium as main components,
A glass layer formed on the ferritic stainless steel alloy (Japanese Patent Publication No. 8-32452) has been proposed. These metal substrates are excellent because there is no need to remove undulations generated during the formation of the ceramic substrate or to remove alkali metal components.

However, since these metal substrates have a glass layer, they are difficult to bend similarly to the above-mentioned ceramic substrates. Also, in these metal substrates, when forming a glass layer,
Since it is necessary to bake at a high temperature of 0 ° C. or higher, the adhesion between the iron alloy and the glass layer is reduced, and the disadvantage that the glass layer is separated from the iron alloy tends to occur. Furthermore, in the process of forming the glass layer, there is a problem that defects are caused by air bubbles and foreign substances mixed in the glass layer, and the glass layer is likely to be uneven due to the glass not being melted uniformly during firing, resulting in poor yield. there were. Furthermore, in the metal substrate, when these are formed, an iron alloy firing step for forming an oxide layer on the surface of the iron alloy and a firing step for forming a glass layer are necessary.
There is a disadvantage that the number of manufacturing steps is large and the manufacturing cost is high.

Another example of a metal substrate includes a ferritic stainless steel alloy containing iron and chromium as main components and an insulating layer formed on the ferritic stainless steel alloy with a heat-resistant resin such as polyimide. (Japanese Patent Publication No. 8-32452) and those in which an insulating layer of a thermosetting resin such as a silicon resin or an epoxy resin is formed on a metal have been proposed.

However, a metal substrate using a heat-resistant resin, a thermosetting resin, or the like as the insulating layer has a problem because it has an insufficient adhesion between the insulating layer and the metal, and is easily peeled off. In addition, this metal substrate has insufficient adhesion between the insulating layer and the resistor formed on the insulating layer. Therefore, it has been proposed to form a dielectric thin film such as SiO ₂ on the insulating layer. However, in this case, since the adhesion between the insulating layer and the dielectric thin film is weak, it is necessary to newly form a layer having excellent adhesion between the insulating layer and the dielectric thin film between the insulating layer and the dielectric thin film. Therefore, there is an inconvenience that the number of manufacturing steps increases and the manufacturing cost increases.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and solves such a problem. It has good adhesion between the base and the insulating layer, and does not require firing.
It is an object of the present invention to provide a thermal head substrate that can be easily manufactured and is suitable for bending. Also,
It is an object to provide a thermal head using this thermal head substrate.

[0008]

In order to solve the above-mentioned problems, a thermal head substrate of the present invention comprises 5 to 3 chromium.
A substrate comprising an iron alloy containing 0% and an insulating layer having a thickness of 1 to 40 μm formed on the substrate. By using such a thermal head substrate, good heat resistance can be obtained, and when the thermal head substrate is subjected to bending processing, cracking of the insulating layer itself does not easily occur, and It can be suitable for a bending process in which the insulating layer is not easily separated from the substrate. In addition, since a general ferrite-based stainless steel or martensitic-based stainless steel can be used as the substrate, the material can be easily obtained and the cost can be reduced.

According to another aspect of the present invention, there is provided a thermal head substrate formed of an iron alloy containing 5 to 30% of chromium and 7 to 80% of nickel, and a substrate formed on the substrate. It has an insulating layer having a thickness of 1 to 40 µm. By using such a thermal head substrate, it is possible to obtain excellent corrosion resistance to oxidizing acids and non-oxidizing acids, and when performing bending on the thermal head substrate, an insulating layer It is suitable for a bending process in which cracking of the insulating layer itself does not easily occur and peeling of the insulating layer from the substrate hardly occurs. In addition, a general austenitic stainless steel or a martensitic stainless steel can be used as the base, so that the material can be easily obtained and the cost can be reduced.

In order to solve the above-mentioned problems, a thermal head substrate according to the present invention comprises a substrate made of an iron alloy containing 35 to 80% of nickel, and a substrate formed on the thermal head substrate having a thickness of 1 to 50%. And a 40 μm insulating layer. By using such a thermal head substrate, a substrate having a low coefficient of thermal expansion is obtained, and the difference in thermal expansion coefficient between the substrate and the material used for the insulating layer is reduced. It is possible to provide a thermal head substrate that is unlikely to occur and is less likely to warp. Furthermore, since it has an insulating layer having a thickness of 1 to 40 μm, when the thermal head substrate is bent, the insulating layer itself is hardly cracked, and the insulating layer is hardly peeled off from the base. It can be suitable for bending. Further, since a general permalloy can be used as the base, the material can be easily obtained and the cost can be reduced.

In order to solve the above-mentioned problems, a thermal head substrate according to the present invention comprises Fe, Si, Mg, Cu,
At least one selected from the group consisting of Ti and V
% Of aluminum or an aluminum alloy, and an insulating layer having a thickness of 1 to 40 μm formed on the substrate. With such a thermal head substrate, the substrate can be made lighter, and when the thermal head substrate is subjected to bending processing, cracking of the insulating layer itself does not easily occur, and the insulating layer from the base is hardly formed. It can be suitable for a bending process in which peeling of hardly occurs. When the substrate is made of an aluminum alloy, the tensile strength can be improved, and a favorable substrate for a thermal head can be obtained.
Further, since general aluminum or aluminum alloy can be used as the base, the material can be easily obtained and the cost can be reduced.

In the above-mentioned substrate for a thermal head, it is desirable that a natural oxide film is formed on the surface of the base. With such a thermal head substrate, the adhesion between the substrate and the insulating layer can be improved, and the thermal head substrate with excellent adhesion between the substrate and the insulating layer can be obtained.

In the above thermal head substrate, it is preferable that the insulating layer is formed by a thin film forming technique. By using such a substrate for a thermal head, the firing step can be omitted, and the manufacturing can be facilitated. In addition, an insulating layer having excellent adhesion to the base can be formed, and a thermal head substrate from which an excellent thermal head can be obtained.

Furthermore, it is desirable that the above-mentioned substrate for a thermal head has a shape in which a part thereof is protruded in a band shape. By using such a substrate for a thermal head, for example, when used in a printer or the like, it is possible to improve the adhesion between a heating portion formed on a raised portion and a sheet to be printed, Can improve the printing performance.

[0015] The above problem can be solved by a thermal head using the above-described substrate for a thermal head. Since such a thermal head uses the above-described substrate for a thermal head, the adhesion between the base and the insulating layer is improved, and the product yield is improved, so that the thermal head can be made inexpensive.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
FIG. 1 is a sectional view showing an example of the thermal head substrate of the present invention. This thermal head substrate 10 is made of a substrate 1 made of an iron alloy on which a natural oxide film 20 is formed.
And an insulating layer 2 formed on the base 1.

In this thermal head substrate 10,
The base 1 preferably has a thickness of about 0.05 mm to 1 mm. When the thickness is less than 0.05 mm,
It is not preferable because heat hardly diffuses in the substrate 1 and adversely affects the performance of a thermal head using the same. on the other hand,
If the thickness exceeds 1 mm, bending of the substrate 1 becomes difficult, which is not preferable. Further, it is desirable that the substrate 1 has a smooth surface.

The substrate 1 is preferably made of an iron alloy containing 5 to 30% of chromium, and is preferably one on which a natural oxide film 20 is formed without performing any special treatment. When the chromium content of the iron alloy is set to less than 5%, for example, when it comes into contact with or uses various corrosive gases for dry etching or an etchant for chemical etching during the production of a thermal head. When the thermal head is used, it is not preferable because sufficient corrosion resistance cannot be obtained when the thermal head is used in a high temperature and high humidity environment. On the other hand, if the content is more than 30%, it is not preferable because it is easily corroded by hydrochloric acid or sulfuric acid.

Specific examples of the iron alloy containing 5 to 30% chromium used for the substrate 1 include SUS430,
Ferritic stainless steels such as SUS430F and SUS434 are preferably used.

The insulating layer 2 has a thickness capable of providing a withstand voltage required for a thermal head. The thickness is not particularly limited. However, when the substrate 10 is bent, the insulating layer 2 has a thickness of 1 to 40 μm. It is desirable to have a thickness of When the thickness of the insulating layer 2 is less than 1 μm, it is not preferable because a required withstand voltage is hardly obtained. On the other hand, when the thickness is more than 40 μm, the insulating layer 2 is easily peeled off from the base 1. Is not preferred.

As the material used for the insulating layer 2, one or more general oxide-based materials capable of forming the insulating layer 2 by a thin film forming technique can be used. Although not limited, specifically, for example,
Sialon, which is composed of four elements of Si, Al, O, and N and other additives, SiO ₂ , Al ₂ O ₃ , T
iO ₂ or the like is preferably used.

In order to manufacture such a thermal head substrate 10, for example, an insulating layer 2 is formed by a thin film forming technique on a substrate 1 made of an iron alloy on which a natural oxide film 20 is formed. Will be The thin film forming technique used here is not particularly limited, but a vapor deposition method, a sputtering method, a CVD method and the like are preferably used.

In such a thermal head substrate 10, a substrate 1 made of an iron alloy containing 5 to 30% of chromium is used.
Therefore, the heat resistance can be improved. Therefore, a general ferrite-based stainless steel can be used as the base 1, a material can be easily obtained, and an inexpensive one can be obtained. Further, since the insulating layer 2 having a thickness of 1 to 40 μm is provided, when the thermal head substrate 10 is bent, the insulating layer 2 itself is not easily cracked.
The thermal head substrate 10 is suitable for a bending process in which the insulating layer 2 is not easily separated from the base 1.

Further, by forming the base 1 on which a natural oxide film 20 is formed on the surface, the adhesion between the base 1 and the insulating layer 2 can be improved, and the base 1 and the insulating layer 2 can be improved. Thermal head substrate 10 having excellent adhesion to the substrate. In addition, since there is no need to provide a step for forming an oxide film, it can be easily manufactured and the manufacturing cost does not increase.

Further, by forming the substrate 1 having a smooth surface and forming the insulating layer 2 by a thin film forming technique, the insulating layer 2 having a smooth and uniform surface can be formed. The thermal head substrate 10 can be used. Further, as compared with the case where the insulating layer is formed by melting glass, unevenness in forming the insulating layer 2 can be reduced, and the yield can be improved.

Further, by forming the insulating layer 2 by a thin film forming technique, a baking step can be omitted, and the production becomes easy. Furthermore, the insulating layer 2 having excellent adhesion to the base 1 can be formed, and the thermal head substrate 10 from which an excellent thermal head can be obtained.

Further, by setting the thickness of the substrate 1 to about 0.05 to 1 mm, the substrate can be easily bent by a general method such as pressing. Furthermore, when the insulating layer 2 has a thickness of 1 to 40 μm, when the thermal head substrate 10 is bent, the insulating layer 2 itself is hardly cracked, and the insulating layer 2 from the base 1 is hardly cracked. Thermal head substrate 1 that is less likely to peel off and has excellent bending workability.
It can be set to 0. Further, the base 1 is 0.05 to 1 m
m and a thickness of about 1 to 40
Since the thickness is set to μm, the thickness of the thermal head substrate 10 itself is smaller than that of a conventional metal substrate or the like, and the thermal head substrate 10 excellent in processability such as cutting can be obtained.

The thermal head substrate 10 of the present invention
Then, as shown in the above-described example, the base 1 is
It can be made of an iron alloy containing 0% chromium, but made of an iron alloy containing 5 to 30% chromium and 7 to 80% nickel, or an iron alloy containing 35 to 80% nickel. , Fe, Si, Mg, Cu, T
0 to 30% of at least one selected from the group consisting of i and V
Containing aluminum or an aluminum alloy.

In the iron alloy containing 5 to 30% of chromium and 7 to 80% of nickel used for the substrate 1, when the nickel content is less than 7%, the corrosion resistance to non-oxidizing acids is improved. It is not preferable because it cannot be performed. On the other hand, if the content exceeds 80%, it is not preferable because it is weak to oxidizing acids and the strength is reduced.

Examples of the iron alloy containing 5 to 30% of chromium and 7 to ()% of nickel used for the substrate 1 include SUS301, SUS302, and SUS30.
3, SUS303Se, SUS304, SUS304
L, SUS305, SUS305J1, SUS308,
Austenitic stainless steel such as SUS309S, SUS310S, SUH309, SUH310, SUH3
An austenitic heat-resistant steel such as 30 is preferably used.

The base 1 is made of 5 to 30% of chromium and nickel
When it is made of an iron alloy containing up to 80%, a substrate 10 for a thermal head having excellent corrosion resistance to non-oxidizing acids can be obtained. In addition, since general austenitic stainless steel or martensitic stainless steel can be used as the base 1, the material can be easily obtained and the cost can be reduced.

The nickel used for the substrate 1 is 35
As an iron alloy containing up to 80%, an alloy generally called permalloy is preferably used. When the nickel content of the iron alloy containing 35 to 80% of nickel is less than 35% or more than 80%, the substrate 1 is made of a material having a large coefficient of thermal expansion and generally having a small coefficient of thermal expansion. The difference from the insulating layer 2 increases,
It is not preferable because the thermal head substrate 10 is likely to be warped or the insulating layer 2 is easily peeled.

When the base 1 is made of an iron alloy containing 35 to 80% of nickel, the coefficient of thermal expansion of the substrate 1 can be reduced, and a value close to the coefficient of thermal expansion of the material used for the insulating layer 2 can be obtained. Therefore, it is possible to obtain an excellent thermal head substrate 10 in which the substrate 1 is less likely to be warped due to a difference in thermal expansion coefficient.

The aluminum or aluminum alloy used for the substrate 1 may be Fe, Si, M
Preferably, it contains at least one selected from the group consisting of g, Cu, Ti, and V in an amount of 0 to 30%.
When the base 1 is made of aluminum or aluminum alloy, a light thermal head substrate 10 can be obtained. In addition, since general aluminum or aluminum alloy can be used as the base 1, materials can be easily obtained, and the cost can be reduced. When the substrate 1 is made of an aluminum alloy, the tensile strength can be improved, and a favorable thermal head substrate 10 can be obtained.

FIG. 2 is a sectional view showing another example of the thermal head substrate of the present invention. The thermal head substrate 30 includes a base 1 made of an iron alloy on which a natural oxide film 20 is formed, and an insulating layer 2 formed on the base 1. This thermal head substrate 30
However, the difference from the thermal head substrate 10 shown in FIG. 1 is that a raised portion 7 having a belt-like raised shape is formed on a part of the thermal head substrate 30. The raised portion 7 is preferably formed, for example, in a state of being built in a printer or the like so as to be perpendicular to a sheet to be printed.

In order to manufacture such a thermal head substrate 30, for example, a natural oxide film 2 having a belt-like raised shape by being bent by a method such as pressing.
0 is formed on the base 1 on which the insulating layer 2 is formed by a thin film forming technique.

In such a thermal head substrate 30, the raised portion 7 having a band-like raised shape is formed in a part of the thermal head substrate 30. For example, when the printer 30 is used in a printer or the like, it is possible to improve the adhesion between the heat generating portion formed on the raised portion 7 and the paper to be printed, and improve the printing performance of the printer or the like. it can. Further, by forming the raised portion 7 so as to be perpendicular to the paper to be printed, printing performance of a printer or the like can be improved.
The thermal head substrate 30 can be further improved.

The thermal head of the present invention is a thermal head using the thermal head substrates 10 and 30. FIG. 3 is a sectional view showing an example of the thermal head of the present invention. In FIG. 3, reference numeral 10 denotes a thermal head substrate. This thermal head substrate 10
On the upper side, a resistor 3 is formed. On the resistor 3, an individual electrode 4a and a common electrode 4b are provided separately. The individual electrode 4a on the resistor 3
The portion located between and the common electrode 4b is the heat generating portion 5. A protective layer 6 is formed on and around the heat generating portion 5.
It is in a state covered by.

In this thermal head 40, the resistor 3 can be made of a resistor generally used as the resistor 3 of the thermal head 40, and is not particularly limited, but TaSiO ₂ or the like is preferably used. Is done. Further, the material for forming the individual electrode 4a and the common electrode 4b is not particularly limited, but an Al alloy or the like is preferably used.

The protective layer 6 is formed by:
The protective layer 6 is made of one or more materials generally used, and sialon or the like is preferably used. It is preferable that the protective layer 6 is made of the same material as the insulating layer 2 because adhesion between the protective layer 6 and the insulating layer 2 becomes very good.

In order to manufacture such a thermal head 40, for example, a film of the resistor 3 is formed on the thermal head substrate 10 shown in FIG. 1 by a sputtering method or the like, and the film is formed by a method such as photolithography. A desired resistor 3 pattern is formed. Then, the resistor 3
The individual electrode 4a and the common electrode 4b are provided thereon by a method such as photolithography so as to be separated from each other. At this time, a portion located between the individual electrode 4a and the common electrode 4b on the resistor 3 is a heating portion 5. Then, the protective layer 6 is formed by a sputtering method or the like so as to cover the heating portion 5 and its surroundings.

Since such a thermal head 40 uses the thermal head substrate 10, the adhesion between the base 1 and the insulating layer 2 is improved, and the product yield is improved. can do.

FIG. 4 is a sectional view showing another example of the thermal head of the present invention. In FIG. 4, reference numeral 30 indicates a thermal head substrate. The resistor 3 is formed on the thermal head substrate 30. On the resistor 3, an individual electrode 4a and a common electrode 4b are provided separately. A portion located between the individual electrode 4a and the common electrode 4b on the resistor 3 is a heat generating portion 5. The heat generating portion 5 and its surroundings are covered with a protective layer 6. This thermal head 50 is the same as the thermal head 40 shown in FIG.
The difference is that the thermal head substrate 30
The thermal head substrate 30 shown in FIG. 2 has been used.

Since such a thermal head 50 uses the thermal head substrate 30, the adhesion between the base 1 and the insulating layer 2 is improved, and the product yield is improved. can do. Also,
Since the thermal head 50 has a heating portion 5 provided on a raised portion 7 having a shape protruding in a band shape formed on a part of the substrate 30 for the thermal head,
For example, when used in a printer or the like, the adhesiveness between the heating section 5 and the paper to be printed is excellent, and the printing performance of the printer or the like can be improved.

[0045]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. [Test Example 1] SUS which is an austenitic stainless steel
The substrate 1 having a thickness of 0.2mm made of 304, is subjected to bending by pressing, after the raised features in a strip, the thickness of SiO ₂ on the surface 10μm
Are formed by sputtering, respectively,
A thermal head substrate 30 as shown in FIG. 2 was obtained. [Test Example 2] Test Example 1 was performed with the thickness of the insulating layer 2 set to 20 µm.
In the same manner as in the above, a thermal head substrate 30 was obtained. Test Example 3 Test Example 1 where the thickness of the insulating layer 2 was 30 μm.
In the same manner as in the above, a thermal head substrate 30 was obtained.

Test Example 4 The thickness of the insulating layer 2 was 0.5 μm
In the same manner as in Test Example 1, the thermal head substrate 30
I got Test Example 5 Test Example 1 where the thickness of the insulating layer 2 was 50 μm
In the same manner as in the above, a thermal head substrate 30 was obtained.

Of the thermal head substrates 30 thus obtained, Test Examples 1 to 3 are examples of the present invention, and Test Examples 4 and 5 are comparative examples.

As a result, in Test Examples 1 to 3 in which the thickness of the insulating layer 2 is set in a preferable range, it is possible to obtain an insulating voltage required as a thermal head and to form the insulating layer 2 in a short time. Was completed. Further, in Test Example 4 in which the thickness of the insulating layer 2 was less than the preferable thickness, it was not possible to obtain an insulation voltage necessary for a thermal head, and in Test Example 5 in which the thickness of the insulating layer 2 exceeded the preferable thickness. In this case, it took a long time to form the insulating layer 2, which was not preferable.

Test Example 6 A film of the resistor 3 was formed on the thermal head substrate 30 of Test Examples 1 to 5 by sputtering TaSiO ₂ , and a desired resistor 3 pattern was formed by photolithography. Formed. Next, the individual electrode 4a and the common electrode 4b are
After the alloy was sputtered, it was provided by photolithography so as to be separated from each other, and a portion located on the resistor 3 between the individual electrode 4a and the common electrode 4b was defined as a heating section 5. Then, a protective layer 6 was formed by a method of sputtering sialon so as to cover the heat generating portion 5 and its surroundings, thereby producing a thermal head 50 shown in FIG.

The thermal head 5 thus obtained
Each of the thermal heads 50 was subjected to a bending process to bend the entire thermal head 50 in the paper transport direction with the raised portions 7 facing outward. As a result, the thermal head substrate 3 of Test Examples 1 to 3 in which the thickness of the insulating layer 2 was set in a preferable range.
In the thermal head 50 using 0, the radius of curvature is 20 m.
It was confirmed that even if it was small, cracking and peeling of the insulating layer 2 did not occur. Further, the thermal head substrate 3 of Test Example 5 in which the thickness of the insulating layer 2 exceeds the preferred thickness
In the thermal head 50 using 0, the radius of curvature is 30 m.
At about m, the insulating layer 2 cracked.

[0051]

As described above, the thermal head substrate of the present invention has an insulating layer having a thickness of 1 to 40 μm. Therefore, when the thermal head substrate is bent, the insulating layer itself is used. This is suitable for a bending process in which cracking of the insulating layer hardly occurs and peeling of the insulating layer from the substrate hardly occurs.

Further, when the substrate is made of an iron alloy containing 5 to 30% of chromium, good heat resistance can be obtained, and general ferritic stainless steel can be used. Further, by using an iron alloy containing 5 to 30% of chromium and 7 to 80% of nickel, corrosion resistance to non-oxidizing acids can be improved, and
General austenitic stainless steel or martensitic stainless steel can be used.

Further, by using an iron alloy containing 35 to 80% of nickel, a base having a low coefficient of thermal expansion is obtained, and the difference in the coefficient of thermal expansion between the base and the material used for the insulating layer is reduced. In addition, it is possible to provide a thermal head substrate in which peeling of the insulating layer hardly occurs and warpage hardly occurs. Further, a general permalloy can be used as the substrate.

Further, Fe, Si, Mg, Cu, Ti,
By using aluminum or an aluminum alloy containing 0 to 30% of at least one selected from the group of V, the weight can be reduced, and general aluminum or an aluminum alloy can be used. When the substrate is made of an aluminum alloy, the tensile strength can be improved, and a favorable substrate for a thermal head can be obtained.

The base may be made of an iron alloy containing 5 to 30% chromium, an iron alloy containing 5 to 30% chromium and 7 to 80% nickel, an iron alloy containing 35 to 80% nickel, Fe, S
Since it is made of aluminum or an aluminum alloy containing 0 to 30% of at least one selected from the group consisting of i, Mg, Cu, Ti, and V, the material can be easily obtained, and the cost is low. A substrate for a thermal head can be obtained.

Further, by forming a natural oxide film on the surface of the substrate, the adhesion between the substrate and the insulating layer can be improved, and the adhesion between the substrate and the insulating layer can be improved. And a thermal head substrate.

Further, by forming the insulating layer as a thermal head substrate formed by a thin film forming technique,
The sintering step can be dispensed with and the production can be facilitated. In addition, an insulating layer having excellent adhesion to the base can be formed, and a thermal head substrate from which an excellent thermal head can be obtained.

Further, by using a substrate for a thermal head which has a part protruding in a belt shape, for example, when used in a printer or the like, a heating part formed on the protruding part and a sheet to be printed And the printing performance of the printer or the like can be improved.

Since the thermal head of the present invention uses the above-described substrate for a thermal head, the adhesion between the base and the insulating layer is improved, and the product yield is improved. it can.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a thermal head substrate of the present invention.

FIG. 2 is a view showing another example of the thermal head substrate of the present invention.

FIG. 3 is a view showing an example of a thermal head according to the present invention.

FIG. 4 is a view showing another example of the thermal head of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 2 Insulating layer 4a Individual electrode 4b Common electrode 5 Heat generation part 6 Protective layer 7 Ridge part 10, 30 Thermal head substrate 20 Natural oxide film 40, 50 Thermal head

Claims (8)

[Claims] 1. A substrate for a thermal head, comprising: a base made of an iron alloy containing 5 to 30% of chromium; and an insulating layer having a thickness of 1 to 40 μm formed on the base. 2. 5-30% of chromium and 7-80% of nickel
A substrate for a thermal head, comprising: a base made of an iron alloy containing: and an insulating layer having a thickness of 1 to 40 μm formed on the base. 3. A base made of an iron alloy containing 35 to 80% of nickel, and a thickness of 1 to 40 μm formed on the base.
a substrate for a thermal head, comprising: 4. A base made of aluminum or an aluminum alloy containing 0 to 30% of at least one selected from the group consisting of Fe, Si, Mg, Cu, Ti, and V, and a base formed on the base having a thickness of 1%. A substrate for a thermal head, comprising: an insulating layer having a thickness of about 40 µm. 5. The substrate for a thermal head according to claim 1, wherein a natural oxide film is formed on a surface of said base. 6. The thermal head substrate according to claim 1, wherein the insulating layer is formed by a thin film forming technique. 7. The thermal head substrate according to claim 1, wherein a part of the thermal head substrate has a shape protruding in a belt shape. 8. A thermal head using the substrate for a thermal head according to claim 1.