JPS63170901A - Heating resistor and manufacture of the same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a heating resistor used in thermal heads, heaters, and other heating elements, and a method for manufacturing the same.

(Conventional technology) Conventionally, by applying electric power, it becomes a heating element,
Heat generating resistors made of various materials have been proposed for use in heaters, thermal heads, etc.

In recent years, the application of such heating resistors to thin-film thermal heads has attracted attention.

This thin-film thermal head has various structures (hereinafter simply referred to as thin-film thermal head) that print pictures, characters, etc. by coloring the thermal paper and creating a mosaic of dots on the thermal paper. ) has been proposed (for example, in the document ``Metal Surface Technology J 34'').

(13) (1983) P, 271-27? ).

According to this document, the conductive material is tantalum and the electrically insulating material is nitrogen, mainly tantalum nitride (Ta2N
) is used as a heating resistor.

Hereinafter, a case will be described in which tantalum nitride (Ta2N) is used as a heating resistor.

FIG. 5 is a sectional view showing the main parts of a thermal head when conventional tantalum nitride (Ta2N) is used as the heating resistor. In this case, one of the many heating resistors provided on the insulating substrate FIG. 3 is a cross-sectional view focusing on one heating resistor. Note that in this figure, hatching representing a cross section is omitted.

First, 11 is an insulating substrate made of any suitable insulating material such as alumina ceramic, 13 is tantalum nitride (Ta2N
), the heating resistors 15 and 17 are made of, for example, gold (A
The heating resistor 13 is made of tantalum nitride (Ta2N), etc., in order to prevent the heating resistor 13 from deteriorating due to oxidation. For example, an oxidation-resistant film 21 made of a material such as silicon carbide (SiC) is provided, and tantalum pentoxide (
A wear-resistant layer 23 made of a material such as Ta20s) or silicon carbide (SiC) is laminated (see the literature (IEE) for details).
E, Mao1. CHMT-7, no. 3 (September 1984), p. 294-296), and furthermore, in a thermal head as shown in FIG.
The heat generating resistor 13 corresponding to the power supply body 15 and 17 provided at a distance of 3 kg1 becomes a heat generating portion 19 (the shaded portion in the figure).

(Problems to be Solved by the Invention) In the conventional thermal head having such a configuration, the specific resistance of tantalum nitride (Ta2N) is approximately 300 Ω·c.
m or less. Therefore, if the heat generating resistor 13 has a sufficiently thick film thickness so that it can withstand long-term use, the resistance value of the heat generating resistor 13 will increase to the desired resistance value (approximately 102 to 105 rubles). (about Ω*cm).

In addition, when a resistor protective film as an oxidation-resistant film is not provided on the heating resistor, or when this film is insufficiently thick, the energy required for printing ( When energy (hereinafter referred to as applied energy) is applied to the heat generating resistor 13, the resistance value of the heat generating resistor increases due to oxidation and the heat generating resistor deteriorates. For this reason, there was a drawback that thermal recording could only be performed for an extremely short period of time.

Furthermore, if this protective film is made thicker than necessary, the thermal head's temperature rise and temperature fall (thermal response) to application and stop of supply current to the heating resistor will be poor, and high-speed printing will not be possible. Ta.

In addition, in order to cope with recycled thermal transfer, which has been attracting attention in recent years, more energy is required to be applied than with conventional thermal heads when printing with a film.

Therefore, in order to obtain the printing energy necessary for printing,
The current value supplied to the heating resistor must be increased.

However, since there are restrictions on the wiring circuit and driving method of the thermal head, it was necessary to determine the shape of the resistor so that it has a practical resistance value within a limited current value.

6(A) and CB) are plan views showing the planar shape of the heating resistor 13 shown in FIG. 5. FIG.

As mentioned above, in order to effectively operate the heating resistor within a limited current value, the planar shape of the heating resistor shown in FIG. 6(A) is changed to a meandering shape as shown in FIG. 6(E). A technique was used to increase the resistance value by changing the shape of the mold.

However, as can be seen from the figure, the meander-type heating resistor whose planar shape is shown in FIG. There is a problem in that there are limitations in processing technology due to the need to do so.

On the other hand, in place of the heating resistor using tantalum nitride (Ta2N) as described above, the development of a heating resistor in which the electrically insulating material constituting the resistor is made of various compounds is underway. For example, silicon nitride (SiNx) or silicon oxide (SiOx) is used as a compound used as such an electrically insulating material, and tantalum (Ta) is used as a conductive material.
Heat generating resistors constructed as such are known, but these materials also have a problem in that they do not have sufficient heat resistance and oxidation resistance.

The purpose of this invention was to solve the above-mentioned conventional problems, and to provide a thermal head that can increase printing speed and print quality and is highly durable. An object of the present invention is to provide a resistor and a method for manufacturing the same.

(Means for solving the problem) In order to achieve this object, the heating resistor which is the first invention of this application has a heating resistor made of a conductive material and an electrically insulating material. It is characterized by being made by adding carbon (C) to the material silicon carbide (SiC).

In addition, in the above-mentioned electrically insulating material, the weight of the carbon (C) to be added and the silicon carbide (as the electrically insulating material)
It is preferable to sputter a target to which carbon (C) is added so that the ratio (C/SiC) to the weight of SiC is 0.05 or more.

Furthermore, the above-mentioned conductive materials are tantalum (Ta), titanium (
Ti), niobium (Nb), tungsten (W), molybdenum (Mo), zirconium (Zr), chromium (Cr)
It is preferable to use one or more metals selected from the group of.

Further, according to the method for manufacturing a heat generating resistor of the second invention of this application, when forming a heat generating resistor made of a conductive material and an electrically insulating material by a sputtering method, a target is
Tantalum (Ta), niobium (Nb) as conductive materials,
Titanium (Ti), tungsten (W), molybdenum (M)
o) one selected from the group of zirconium (Zr) and chromium (Cr), or two or more metals selected from these metals, and silicon carbide (SiC) and carbon as electrical insulating materials. It is characterized in that sputtering is performed simultaneously as a target containing (C).

Furthermore, in the method for manufacturing a heating resistor described above, the target for sputtering is silicon carbide (SiC) as the electrically insulating material and carbon (C) to be added.
and a target comprising the above-mentioned metal are separately prepared.

It is also suitable to overlap these two targets and perform sputtering at the same time.

Further, in the method for manufacturing a heating resistor described above, a target for sputtering includes silicon carbide (SiC) as an electrically insulating material and carbon (C) to be added, and a target for sputtering to be added with the metal. It is also suitable to superimpose a target made of carbide and perform sputtering at the same time.

(Function) According to the configuration of the present invention, silicon carbide is used as the electrically insulating material constituting the heating resistor, and by adding carbon to this electrically insulating material, it has excellent durability such as heat resistance and oxidation resistance. A heat generating resistor can be realized.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the drawings. An example will be described in which the heating resistor, which is the first invention of this application, is used as a thermal head using the manufacturing method of the second invention of this application. In addition, FIGS. 1 to 4 used for explaining the following embodiments are only schematic illustrations to the extent that the present invention can be understood, and the dimensions of each component,
The shape and arrangement relationship are not limited to the illustrated example.

FIG. 1 is a cross-sectional view of a main part showing the configuration of a thermal head as a heating resistor of the present invention. This figure, like FIG. 5, is a sectional view focusing on one of the many heating resistors provided on the insulating substrate. Further, in this figure, hatching indicating a cross section is omitted.

In FIG. 1, numeral 11 indicates an insulating substrate, and this insulating substrate l
A heating resistor 25 made of silicon carbide as an electrically insulating material and carbon added thereto is provided on the heating resistor 25 . This heating resistor 25 is made of Ta, Nb, Ti
, W, Mo, Zr, and Cr, or two or more metals selected from these metals. In addition, power feeders 15 and 17 made of the above-mentioned material are provided in spaced apart areas on the surface of the heating resistor 25, and a portion between these power feeders 15 and 17 (indicated by diagonal lines in the figure) is provided. ) is the heat generating part 18. Furthermore, since the heating resistor of the present invention has excellent durability (described later),
The power supply body 15 does not require an oxidation-resistant film as explained in the figure.
17 and the heating resistor 25, a wear-resistant film 2 is placed directly on the heating resistor 25.
It has a structure in which 3 layers are stacked.

Hereinafter, with reference to the drawings, a method for manufacturing a thermal head will be described as an example of the manufacturing method that is the second invention of this application, and the heating resistor of the invention will be described in further detail. Note that the examples described below will be described in the case where tantalum is used as the conductive material.

First, a Ta-3i-C resistive film is deposited as the heating resistor 25 on an insulating substrate ll made of, for example, alumina ceramic by high frequency sputtering (RF sputtering). The formation of the heating resistor 25 is as follows.

Various conductive materials and electrically insulating materials were formed with various composition ratios, and the following method was used to compare the characteristics of each heating resistor.

FIG. 2 is an explanatory plan view showing a target used in the RF sputtering method in order to explain this formation method. A small piece of, for example, a fan-shaped conductive material made of tantalum (Ta) (hereinafter, this The small pieces are referred to as conductive material 29) are placed one on top of the other, and both are simultaneously subjected to RF sputtering in an inert gas such as argon. At this time, the composition ratio of the electrically insulating material 27 and the electrically conductive material 28 can be changed by using various targets in which the center angle 0 of the fan-shaped electrically conductive material 29 is varied as shown in FIG. can. By this method, the surface resistance of the heating resistor 25 is approximately 150Ω.
The central angle θ was adjusted to an angle in the range of 30 to 40 degrees so that the angle was 30 to 40 degrees. By the method of this example, a heat generating resistor 25 was created in which the proportion of tantalum, which is a conductive material, in the heat generating resistor was approximately 30 to 40% by weight. however,
The proportion occupied by this conductive material can be set to the same composition ratio as the composition ratio of the conductive material in a conventional heating resistor made of tantalum nitride (C2N) or the like. Also,
In this embodiment, the film thickness of the heating resistor 25 is 300 mm.
The film thickness is OA and is 180 m x 1 on the insulating substrate 11.
A pattern of 80 JLm was formed by a conventionally well-known etching technique.

Subsequently, the above-described power supply bodies 15 and 17 were formed on the heating resistor 25 formed by the above-described method, and silicon carbide (SiC) was formed thereon to a thickness of 3 m as a wear-resistant layer. .

Hereinafter, the characteristics of the heating resistor of the present invention will be explained with reference to the drawings.

First, in the target as the electrically insulating material 27, the weight percent of carbon (C) added to silicon carbide (SiC) is
A life test was conducted on a thermal head constructed of a heat generating resistor formed in a range of 0 to 30 tonne percent (ratio of added carbon to the total weight of silicon carbide and carbon). This life test is a step stress test in which the applied force is gradually increased in predetermined steps.
Apply power at each step with a pulse width of 1.60
! II S e C + repetition time 2.78 m s
e c +7) by continuously applying 20,000 pulses. The results are shown in FIG.

Figure 3 shows the resistance value change rate in % on the vertical axis.
FIG. 3 is a characteristic curve diagram in which the imprinted Nercy is plotted on the horizontal axis in units of mJ. In the figure, the content of carbon added to the electrically insulating material 27 is 0% by weight (C/Si
C=0), 2.5% by weight (C/SiC=0
．． Q25θ), the weight is 5.0% by weight (C/5iC=0
．． 0526), Δ is IO capacity% (C/5iG=Q, 1
ll), 20% by weight (C/SiC=0.250
), 01t30% by weight (C/SiG = 0.429
) shows the resistance change rate for the combination of j and m. In addition, the resistance change rate is determined by measuring the resistance value of the heating resistor every time the application of a predetermined number of pulses is completed in each step, and using this value and the resistance value (R) before the test, the resistance value of the heating resistor is calculated. Calculate the amount of change (ΔR) and calculate the resistance change rate (ΔR/R) with respect to the resistance value before the test.
is calculated.

As can be understood from this figure, when the weight percent of carbon added to the electrical insulating material 27 is 5 weight percent or more, the resistance change rate (ΔR/R) is improved, and furthermore, the rate of change in resistance (ΔR/R) is improved. When it is 20% by weight or more, the change in resistance I1 is small even if the applied energy is increased.

Next, in order to compare with conventional heating resistors, we will compare the cases where the electrical insulating material is nitrogen (the heating resistor is tantalum nitride (Ta2N)) and the case where the heating resistor is silicon nitride (
The heating resistor is silicon nitride and tantalum (Ta-9i-N)
A step stress test was conducted on the case formed by the above method.

The thermal head used for this comparison was manufactured under the same conditions as the above-described thermal head according to the present invention, except that nitrogen or silicon nitride was used as the electrically insulating material. Further, a comparison was made in the case where the amount of carbon added to the electrical insulating material 27 of the heating resistor made of Ta-5 knee C used in this comparison was 30% by weight. The results are shown in FIG.

In Figure 4, like Figure 3, the vertical axis shows the resistance change rate (ΔR/
R) is a characteristic curve diagram showing applied energy on the horizontal axis. In the same figure, when the heating resistors constituting the thermal head are Ta-5i-C, ◯ indicates Ta-5i-C, and Δ indicates Ta-5i-C.
In the case of 2N, mu indicates the case of Ta-5i-H.

From this figure, it can be seen that the heating resistor made by using silicon carbide as the electrically insulating material of this invention 11 and adding carbon to this electrically insulating material exhibits less deterioration due to high applied energy than the conventional heating resistor. few.

Incidentally, the heating resistor of the present invention is not limited to the above-mentioned embodiments. For example, in this example, the 11 combination of added carbon and silicon carbide is 0.052fi or more and 0.4
29 or less (wt% of carbon added to electrically insulating material 27)
This corresponds to 5.0% by weight or more and 30% by weight or less. Although the present invention has been described in detail within the preferred range of 0.05, the same effects as those of the above-mentioned embodiments can be obtained as long as this ratio exceeds about 0.05. However, when forming a heating resistor into a desired pattern using etching technology, if the amount of added carbon (or carbon content) is high, the etching speed will decrease, which may cause problems in terms of processability. be.

In addition, in this example, in order to make a comparison with the conventional one,
Although the case where the conductive material is tantalum has been described, the present invention is not limited to this, and as mentioned above, tantalum (Ta) can be used.
, niobium (Nb), titanium (Ti), tungsten (W
), molybdenum (No), zirconium (Zr), chromium (Cr), or one metal selected from a series of materials conventionally used as conductors in this field, such as Even when two or more types of metals were selected, the same effects as in the above-mentioned embodiments could be obtained.

Furthermore, in the manufacturing method described in this example, the case where the surface resistance is equivalent (approximately 150 Ω/mouth) was compared and explained, but this value is in the practical range of approximately 102 to 105 Ω*cm. It can be formed as a value corresponding to

Furthermore, in the above-described embodiment, a target made by adding carbon to silicon carbide as an electrically insulating material and a target made only of tantalum as a conductive material are sputtered at the same time. Here, for example, a heating resistor can be created by simultaneously sputtering a target made of silicon carbide with carbon added and a target made of tantalum with carbon added, in the same manner as in the method explained with reference to FIG.

Furthermore, at this time, it is clear that various modifications can be made within the scope of the object of the present invention, such as sputtering carbon, silicon carbide, and tantalum to be added as a single target.

(Effects of the Invention) As can be understood from the above explanation, the heating resistor of the present invention has excellent heat resistance and oxidation resistance because it is constructed by adding carbon to silicon carbide, which is an electrically insulating material. There is. Therefore, even when high energy is applied to this heating resistor, the change in resistance I1 is extremely small.
No rough breaks occur. Therefore, when the heating resistor of the present invention is used in a thermal head, for example.

It is sufficient to provide only the wear-resistant layer instead of providing a dual-structure protective film consisting of an oxidation-resistant film and a wear-resistant layer on the heating resistor as in the conventional case. Therefore, it is possible to realize a thermal head or the like that is more durable than before, is capable of higher definition, and has better thermal response.

Further, according to the manufacturing method of the present invention, a heating resistor having a desired specific resistance can be obtained by adjusting the content of the conductive material contained in the heating resistor.

Furthermore, the heating resistor of the present invention can be easily formed into a film by simultaneously sputtering the above-mentioned conductive material and electrically insulating material in an inert gas.

Therefore, it is possible to provide a heating resistor that is excellent in heat resistance and oxidation resistance and has a large specific resistance, and to provide a manufacturing method that can easily form such a heating resistor.

More specifically, by using the heating resistor of the present invention, it is possible to provide a thermal head suitable for a regenerative thermal transfer method that requires greater applied energy than conventional ones.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main parts of a thermal head using the heat generating resistor of the present invention, FIG. 2 is an explanatory diagram showing an example of the method for manufacturing the heat generating resistor of the present invention, and FIG. FIG. 4 is a characteristic curve diagram for a detailed explanation of the present invention; FIG. 4 is a characteristic curve diagram for comparing an embodiment of the present invention with the prior art; FIG. 5 is a diagram of the main points of a thermal head for explaining the prior art. FIGS. 6(A) and 6(B) are cross-sectional views showing the shapes of conventional heating resistors and those used to explain the present invention. 11...Insulating substrate, 13, 25...Heating resistor 15.17...Power supply body, 18...Heating part 21
... Oxidation-resistant film, 23... Wear-resistant layer 27 electrically insulating material, 29... Conductive material. Patent applicant: Oki Electric Co., Ltd./q//' Mlt4Ff1. zJ
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t )' (7) Explanatory diagram of the invention in Figure 1 and 2 Figure 2 Mr. 4 @ Mataka prison (7,) Resistance change + (%tsu! 4 There is snoring in the east in winter ＼ 4 moves・Using t+7: To the first circle... Doro Sake Menu Figure 5 Explanatory diagram of the conventional and second inventions Figure 6 Relationship with the case of a person who does the following Patent applicant address (〒-105) 1-7-12 Toranomon, Minato-ku, Tokyo Name (029) Oki Electric Industry Co., Ltd. Representative Nankai Hashimoto 4 Agent 〒170 ffi (986) 5563
Address: 1-20-5 Higashiikebukuro, Toshima-ku, Tokyo Contents of the amendment in Detailed Description of the Invention Column 7 As attached: (1) In the Detailed Description of the Invention column of the specification, on page 6, line 18, “Regenerated thermal sensitive '' should be corrected as ``Iru Thermal Sensitive J.'' (2) Same, page 14, line 7 [, about 30 to 40% by weight.''
The statement has been corrected to ``, about 45-70 Shigesato%J.

Claims (6)

[Claims] (1) A heating resistor made of a conductive material and an electrically insulating material, characterized in that the heating resistor is made by adding carbon (C) to silicon carbide (SiC) as the electrically insulating material. (2) In the electrically insulating material, the ratio of the weight of the added carbon (C) to the weight of silicon carbide (SiC) as the electrically insulating material (C/SiC)
2. The heating resistor according to claim 1, wherein the heat generating resistor is formed by sputtering a target having a value of 0.05 or more. (3) The conductive material is tantalum (Ta), titanium (Ti)
), niobium (Nb), tungsten (W), molybdenum (Mo), zirconium (Zr), and chromium (Cr). The heating resistor according to item 1. (4) When forming a heating resistor made of a conductive material and an electrically insulating material by sputtering, the target is a conductive material such as tantalum (Ta), niobium (Nb), titanium (Ti), or tungsten (W). ),
Molybdenum (Mo), zirconium (Zr), chromium (
A heating resistor characterized in that it is sputtered simultaneously as a target containing one or more metals selected from the group consisting of Cr) and silicon carbide (SiC) and carbon (C) as electrical insulating materials. How the body is manufactured. (5) In the method for manufacturing a heat generating resistor, a target containing silicon carbide (SiC) and carbon (C) as the electrically insulating material and a target made of the metal are overlapped and sputtered at the same time. A method for manufacturing a heating resistor according to claim 4. (6) In the method for manufacturing the heating resistor, the target containing silicon carbide (SiC) and carbon (C) as the electrically insulating material and the target consisting of the metal and carbon (C) are superimposed. 5. The method of manufacturing a heating resistor according to claim 4, wherein sputtering is carried out simultaneously.