JPH0453202A - Heating resistor - Google Patents

Abstract

PURPOSE:To make a change in the electric properties of a heating resistor, especially in the temp. coefficient of resistance by a method wherein two elements of Si and O are added to the resistor base of Ti, Al and N. CONSTITUTION:A glazed alumina substrate is prepared as an insulated substrate 12, a film of Ti-Al-Si-N-O heat generating resistor 24 is formed on the whole surface of a substrate 12a. The film contains 40 to 60wt.% Ti, 10 to 30wt.%, Al 1 to 3wt.% Si, 20 to 20wt.% N and 2 to 10wt.% O. A Ti target 30 and an SiO2 target 32 are placed on an Al target 28, and a heat-generating resistor 24 is formed by conducting a reactive sputtering operation using the mixed gas of Ar and N2. The electric property of the heat-generating resistor 24 is controlled by changing the number of the placed Ti target 30 in the state wherein the fixed number of placed SiO2 target 32 is being maintained and also by changing the compositional ratio of the constituent elements contained in the heat-generating resistor 24. The specific resistance and temperature coefficient of the resistance are changed in accordance with the compositional ratio of the constituent elements of Ti, Al, Si, B and O, especially in accordance with the compositional ratio of Si and O.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a heating resistor suitable for use in a thermal spatula.

(Prior art) Heat-generating resistors that are used to generate heat by passing an electric current through them have been used for heaters, heat-sensitive heads, etc., and a small number of heat-generating resistors have been proposed for each purpose. Hereinafter, a heating resistor used in a thermal head will be explained.

υ−Nruhetsu [~(J) In order to form a mosaic of printed characters representing pictures, letters, etc. on thermal paper, thermal paper is printed with printed characters.
Various structures have been proposed (for example, see the paper published by the Institute of Telecommunications Engineers u'84/3 Vol.

J67-C-No., 3 p., 262-269 Kamataru).

A thin film of tantalum nitride (Ta2N) is often used as the heating resistor of such a thermal head. As is well known, when used as a resistor in an electric circuit, such as 82 N% Hybrid ■C, the stability of its resistance value is very suitable for the electric circuit.
When a Ta2N1 thermal head is used as a heat generating resistor, sufficient resistance desired in a thermal head cannot be obtained regarding its oxidation resistance and heat resistance. Therefore, in order to compensate for this lack of resistance, structural improvements have been made in line with thermal heads. This point will be explained by referring to the detailed drawings.

FIG. 6 is a cross-sectional view schematically showing the configuration of the thermal head, which is one of the many printing elements provided on the insulating substrate (
This shows the configuration that we focused on.

As shown in FIG. 6, the printing element 10 of the thermal head
F is provided on the binding board 12 and consists of I, a heating resistor 14, and a power supply body 16.18 provided on the heating resistor 14 in a spaced apart portion of the heating resistor 14 excluding the heating portion 14a. , the illustrator also placed this printing element f'-10 on an insulating substrate 12.
A large number of thermal heads are provided on one side to form a thermal head. Then, an oxidation-resistant film 20 and a wear-resistant film 22 are sequentially provided on the power supply bodies 16 and 18.

The oxidation-resistant film 20 and the wear-resistant film 22 are protective films for the printing element 10.
．． It prevents the oxidation of a and greatly contributes to extending the life of the thermal head.

FIGS. 7A and 7B are diagrams showing the planar shape of the heating resistor of the thermal spatula 1-.

Heating resistor] In order to extend the life of heating resistor 4,
Is it okay to increase the thickness of the heating resistor 14?The electrical resistivity of Ta2N is as small as 3001"Ω・cm or less, so when the heating resistor 14 is formed using this 1"a2Nu, the planar shape of the heating resistor 14 should be made thicker. As shown in Figure 7 (A), the ribbon shape and ()
As the C film thickness increases, the resistance value of the heating resistor 14 decreases, so in order to obtain the power necessary for printing, the current value to be supplied to the heating resistor 14 must be increased.
However, in order to reduce the cost of the driving IC for the printing element 10, it is necessary to reduce the current value to be supplied to the heating resistor 14. Therefore, a meander-shaped heating resistor 14 or 13, as shown in FIG.

In the meander-shaped type-C, the heating portion 1488 has a narrow meandering pattern, and the heating resistor 14 has a thick film and has a high resistance value that allows sufficient printing for one practical use with a low supply current. Realize.

(Problem to be solved by the invention) However, in recent years, there has been an increasing demand for higher definition printing by thermal heads.

For higher definition printing, is it necessary to color the finer printing marks?
must be miniaturized. However, since the above-mentioned meander-shaped printing element 10 has a heating portion 141 or a narrow meandering pattern, there is a technological limit to miniaturization.

Finer print element: at the 1st time forming f'-10 (
J. It is advantageous to make the planar shape of the heat generating resistor 14 into a ribbon shape or an arched shape. Therefore, even if the heat generating resistor 14 is not shaped like a ribbon and the film thickness is increased, it is not practical for printing. Furthermore, it is desired to develop a high-resistance material that can provide a sufficiently high resistance white. Conventionally, with such high-resistance materials,
For example, Ta-3i-N, [Ha-A-8]-〇A similar resistor material "1" has been developed.These materials are Ta, S
i, a mixture containing N or O -C 1 stop 1.000-
It has a high electrical resistivity ρ of about 100,000 +, -iΩ·cm, but on the other hand, the resistance value has a strong dependence on temperature, and as the temperature rises, the electrical resistivity ρ tends to decrease. For example, the heating resistor 14 with a film thickness of 2000 to 300 C) is formed using a T a -S j-N resistor material.
In this case, the resistance 1 = 2, Ω/temperature coefficient of resistance, -1500--2000ppm/6C. (・
A current increase of about 10 to 20% occurs when the pulsed clove throat is used.

As a result of the resistance value of the heat generating resistor 4 depending on the temperature, the resistance value changes according to the heat generation temperature of the heat generating resistor 14, thereby controlling the power applied to the heat generating resistor 14 during printing. This creates the problem that the amount of heat generated by the heating resistor 4 increases as the temperature of the insulating substrate 10 rises.

An object of the present invention is to provide a heating resistor having a large specific resistance value and a low temperature coefficient of resistance in order to solve the above-mentioned problems of the prior art.

(Means for Solving the Problems) In order to achieve this object, the heating resistor of the present invention is characterized in that it consists of T1, Δρ, Sl, N, and ○.

In carrying out this invention, 40 to 60% by weight of Step 1,
10 to 30% by weight of 8β, 1 to 3% by weight of Si, and 2% of N.
It is preferable to use a heating resistor containing 0 to 30% by weight and 2 to 10% by weight of O.

(Function) The heating resistor of this invention has Ti, Aρ, Si, N and 0'
C-consisting of T-i--Aρ-81-N-
○Resistor (with, 1, Δρ and 11 consisting only of N!-N resistor It can be thought of as a resistor with the addition of two elements, Mace 1 and ○.These additions of Sl and O Hr It is possible to change the electrical properties, particularly the temperature coefficient of resistance, of the C heating resistor.

When using the heating resistor of this invention in a thermal head,
The heating resistor contains 40 to 60% by weight of ``Ding'' and 10 = 3 of 8ρ.
0% by weight, 1-3% by weight of Sl, 20-30% by weight of N.
It is preferable that the heating resistor containing each element in such a composition range is suitable for practical use as a heating resistor of a thermal head and has a high specific resistance of 1 and a practical resistance ( This suitably has a lower temperature coefficient of resistance.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

The drawings are shown schematically to the extent that this invention can be understood ()
It's just that.

This embodiment is an example of a heating resistor for a thermal head, and in the following description, this embodiment will be explained together with a description of the manufacturing process of the thermal head.

3(A) to 3(C) are cross-sectional views showing step by step the manufacturing process of the thermal head, and the manufacturing process when the heating resistor of this example is used in the thermal head having the configuration shown in FIG. 6. An example is shown below.

First, a glazed alumina substrate is prepared as the insulating substrate 12, and as shown in FIG.
The substrate surface 12a of this substrate 12 is
-Fi-△ on the entire surface! A 5i-N-0 heating resistor 24 is formed. This Fl-Δβ-3j, -N-0 heating resistor 24 is made of T1 (titanium), Al2 (aluminum), S
Consisting of i (silicon), N (nitrogen) and O (oxygen),
40-60% by weight of Ti, 10-30% by weight of Aρ, S
1 to 3% by weight of L, 20 to 30% of N, and 2% of ○.
Contains ~10% by weight.

FIG. 4 is a diagram showing the structure of the terquette 1 used for forming the heating resistor 24 of this embodiment, and FIG. 4(A) is a plan view of the terquette, and FIG. FIG. 4 is a cross-sectional view taken along line IVB-IVB of FIG. 4(A).

As shown in Figure 4, Takera 1~ is a disk-shaped β target 2.
8. Fan-shaped T1 target 30 and chip-shaped 510
It consists of 2 targets and 32 targets.

5i()z)9-The kerato 32 is made planar (the shape when folded is, for example, a rectangle with -sides of 15 mm, and the opening angle θ of the target 30 is θ=20°, and 1.:.

In addition, in Figure 4 (A), mark the T1 target 30.
-Indication-4゜T' j-A 12-8 i -N -0 Heat generating resistor 2
When forming the film No. 4, a Ti target 30 and a S]02 target 32 are placed on the Δββ target layer 28, and reactive sputtering is performed using a sputtering gas of a mixture of Ar and N2 to generate heat. A resistor 24 was formed into a film. The heating resistor It is controlled by changing the composition ratio of the constituent elements including 24 and 24. The specific resistance and temperature coefficient of resistance (CR) of the heating resistor 24 are determined by these constituent elements T1, Aj2, Sl,
The composition ratio of Si and O changes accordingly.A film containing % N is formed by reactive sputtering using a mixed gas of Δr and N2. This mixed gas is, for example, 90 volume% Δr and 10 volume% N2
including.

FIG. 2 shows the composition of the film 24 formed using these targets and sputtering gases. FIG. 2 (Each element Tj, A included in the film 24 formed when a total number of m T1 targets 30 are placed on the J△ρ target 28)
The figure shows the composition ratios of β, Si, N, and ○, and the vertical axis is the composition ratio (weight %) of each element including the film 24 formed.
and the horizontal axis is the sum of the opening angle θ of the T1 target - m・θ
(d e q) @ Take and show j and things. In the figure,
Changes in the composition of D1, N, Δβ, ○, and Sl are plotted and expressed as 1, N, Δβ, ○, and Sl, respectively.

As can be understood from FIG. 2, when the number of T] targets h30 is increased and the sum of the opening angles θ is increased -m·θ, the composition ratio of T1 in the deposited film 24 increases. Furthermore, if the total sum of the opening angles θ is decreased, the following trends (■) to (■) can be found. (1) A of the deposited film 24
The composition ratio of β increases () and the film composition becomes Aρ-rich. ■ The composition ratio of T1 in the deposited 1 and film 24 decreases. ■ The composition ratio of N in the deposited 1 and film 24 decreases. To increase,
(2) The composition ratios of Sj and O in the film 1 and the film 24 both decrease.

FIG. 1 (FIG. 4) Electrical characteristics of film 1 and film 24 formed using the target shown in FIG. Figure 1 is a diagram showing the specific resistance and temperature coefficient of resistance TCR of a film formed when the film is formed with the total sum of opening angles of 0 - mθ, and the horizontal axis represents the opening angle. The total sum of θ is shown with specific resistance (mΩ·cm) on the vertical axis on the left and temperature coefficient of resistance (ppm/'C) on the vertical axis on the right.

In the figure, the symbols 0 and dotted lines (j) indicate the targets shown in Figure 4.
This 5102 film is formed without placing the target 32.
The changes in resistivity and temperature coefficient of resistance of the ρ-T1-N film are plotted with signs △ and m, and the solid line is not shown in Figure 4. A film was formed by placing and forming a film.
-Represents changes in resistivity and temperature coefficient of resistance of film 2A.

As can be understood from Fig. 1, Aβ-lower]N-3j-
Although the specific resistance of the ○ film is slightly lower than that of the ApTi-N-3i-○ film 24,
It is possible to increase the temperature coefficient of resistance of △ρT' i -N film to a value closer to zero, and therefore, in the Aρ-Ti-N film, Sj, ,
By adding O, the temperature coefficient of resistance can be significantly improved.

However, according to other experiments conducted by the inventor of this application, excessive addition of 7.J of Sl and ○ increases the resistivity by 300 mΩ・c.
m or more and the temperature coefficient of resistance is -2000--300
0 ppm/'C, and therefore the specific resistance and temperature coefficient of resistance suitable for the heating resistor of the thermal head cannot be obtained.
In order to obtain a heating resistor having a resistivity and temperature coefficient of resistance suitable for the heating resistor of a thermal head, O should be adjusted to 1 to 3
It was confirmed that it is preferable to add 2% to 2% by weight of S] to 2% by weight. In order to obtain the most suitable heating resistor for the heating resistor of the thermal head, Tj 50% by weight, 8! It is preferable to form a heating resistor 24 containing 18% by weight of N, 25% by weight of N, 2% by weight of Sl, and 5% by weight of ○.

Here, as an example, in the process step shown in FIG. Ti-Aρ-8 with a film thickness of approximately 1500% was prepared by using a mixed gas containing 10% by volume and 10% by volume, a sputtering gas pressure of 1×1o″2 TOrr near the substrate, a suba-interbower of 200W, and a sputtering time of 30 minutes. ]-N-〇 It is assumed that the heating resistor 24 is formed into a film.The surface resistance of the heating resistor 24 in this case is approximately 930Ω/hole, and if the heating resistor 24 with such a surface resistance is used, its shape will change. Even if it is processed into a simpler shape, such as a positive shape (see Fig. 7 (A)), without processing it into a meandering shape (see Fig. 7 (B)), it will not be practical in Zamalkhet. The heating resistor 14 having a desired resistance value can be formed.

After forming the heating resistor 24, a power supply body 26 is then formed on the heating resistor 24, as shown in FIG. 3(B).

Next, as shown in FIG. 3(C), the heating resistor 24
Then, the power supply body 26 is buttered to have a ribbon-like planar shape to form a ribbon-shaped heating resistor 14, and then the power supply body 26 is buttered so that the heat generating portion 14au of the heat generation resistor 14 is exposed. Power feeders 16 and 18 are formed on the heat generating resistor 14, sandwiching the heat generating portion 14au and spaced apart from each other.

Next, as shown in FIG. 6, an oxidation-resistant film 20 made of 5102 is formed on the power supply bodies 16 and 18 and the heat generating part +4a, and a T film with a film thickness of 2 Ll rn is roughly formed on the oxidation-resistant film 20.
A wear-resistant film 22 consisting of 205 is formed, and a predetermined number of printing elements 10 are provided at predetermined positions. Complete Ruhell.

Instead of forming a meander type heating resistor 14, it is better to form a ribo'/type heating resistor 14.
,) The first helical sawing improves the yield when 24 heating resistors are battened.
The printing element 10 can be easily miniaturized.

Figure 5 shows an explanation of current changes in the thermal head (Fig. C).
4 is a diagram showing the waveform of a constant voltage drive pulse with a pulse width of 2 ms applied to the heating resistor] 4, where the vertical axis shows the applied voltage and the horizontal axis shows the time (ms) %. Figures 1 and 5 (c) show the changes in the current flowing through the heating resistor 14 when a constant voltage drive pulse with the waveform shown in Figure 5 (B) is applied, and the vertical axis shows the change in the current flowing through the heating resistor 14. The current flowing through the resistor 14 and the time difference (ms) are plotted on the horizontal axis.1. :. Figure 5 (c)
In the middle, the heat generating resistor 14 of the thermal head is the surface resistance 930Ω/glue star type T1- formed in 1 and Example above.
ρ-N-3]-〇 film and formed separately from this 1. : Ribbon type Ta- with resistance temperature coefficient -2200ppm/°C
3i-0 film, the changes in the current flowing through the heating resistor 14 are shown by solid lines and dotted lines, respectively.

Ti-An-N-3i-0 and 1-a-Sj-
In both cases, the temperature coefficient of resistance of the heating resistor 14 is negative, so as can be understood from FIG. The resistance of decreases and the current increases. However, the current change rate Δi・100/i (%) is
In the case of the i-〇 film, the current change is about 20 to 30%, whereas in the case of the Tj, -Aρ-N-3i-〇 film of the above-mentioned example, it is about 4%, and the current change is It is possible to keep the rate of change very low.For printers and facsimile machines, it is desired that the rate of change in current during printing be within 10%.
Therefore, the current change rate of 4% is a value that is fully satisfactory for practical purposes.
be.

This invention is applicable to the embodiments described above (but is not limited thereto, and therefore, the shape, number, dimensions, film thickness, formation conditions, film formation method, numerical conditions, and conditions of each component may be modified as desired). (This can be changed.

For example, in addition to the target used in the film formation described in Embodiment 1 described above, targets (1) to (4) listed below may be used.

(1) Mixed Targetera 1 to 1 consisting of three substances Ti-N, Δf2N and 5iOz (2) Mixed target consisting of T1N, AnN and 513N4 (3) Mixed target (4) consisting of TiN, Aβ203 and 5in2 ) A mixed target consisting of TiN, AρN, and Sl:+I'J4 When using the mixed targets (1) to (4), any one of the following sputtering gases can be used in either case. .

■ Mixed gas of △r and N2 (mixed gas of ψAr, N2 and 02 ■Gas of only Har (effects of the invention) As is clear from the above explanation of L/, according to the heating resistor of the present invention, A resistor base consisting only of Tj, Aρ and N (this S]- and ○ can be considered as the additive Ll1, and depending on the amounts of these S] and ○, the heating resistor's Electrical properties (temperature coefficient of resistance) can be changed.

When using the heating resistor of this invention in a thermal head,
Heating resistor (40 to 60% by weight of Ti, 10% of Af2)
Preferably, the content is 30% by weight, 1 to 3% by weight of Sl, 20 to 30% by weight of N, and 2 to 10% by weight of 0. By forming a heating resistor containing each element in such a compositional range, it is suitable for practical use as a heating resistor of a simpler shape than a meandering type, for example, a 1-no-bon type heating resistor as well as a heating resistor of a thermal head. 1, it is possible to form a heating resistor with a high resistance value of 1. Therefore, it is easy to reduce the current of the driver IC for driving the heating resistor of the thermal head, and production costs can be reduced by using a driver IC that operates with low current. This gives rise to the advantage of Furthermore, by forming a ribbon-shaped heating resistor in the thermal head, there is an advantage that the heating resistor can be easily miniaturized.

Furthermore, by forming a heating resistor containing each element in the composition range as described above, it is possible to form a heating resistor that has a low temperature coefficient of resistance closer to zero, and therefore has a smaller resistance value when energized. Therefore, it becomes easy to control the applied power when driving the thermal head.

[Brief explanation of drawings]

Figure 1 shows the electrical characteristics of the deposited film, Figure 2 shows the composition of the deposited film, and Figures 3 (C) to (C) outline the manufacturing process of the thermal head. Figures 4 (A) to (B) are diagrams showing examples of target configurations, and Figures 5 (A) to (B) are diagrams for explaining changes in current flowing to 9-margin. FIG. 6 is a diagram showing a configuration example of a printing element of a thermal head, and FIGS. 7(A) to 7(B) are diagrams showing a planar shape of a heating resistor of a thermal spatula 1. 14.24... Heat generating resistor. Patent applicant Oki Electric Industry Co., Ltd. +60 Sum of opening angles θ (d e 9) Electrical characteristics of the deposited film Figure 1 Composition of the deposited film Figure 2 Configuration example of the printing element of the thermal head 4a

Claims (2)

[Claims] (1) A heating resistor characterized by being made of Ti, Al, Si, N and O. (2) 40-60% by weight of Ti, 10-30% by weight of Al, 1-3% by weight of Si, 20-30% by weight of N, and O
The heating resistor according to claim 1, characterized in that it contains 2 to 10% by weight of.