JPS62119056A - Thermal head - Google Patents

Abstract

PURPOSE:To obtain a thermal head of high performance available in high power, by providing an Si layer at least either between a heating resistor layer and a heat-reserving layer consisting of a material containing oxygen as an ingredient or between the heating resistor layer and a protective layer consisting of a material containing oxygen a an ingredient. CONSTITUTION:On a substrate 1 of ceramic etc., a glazed heat-reserving layer 2 mainly composed of SiO2, a first Si layer 7, and a heating resistor layer 3 of Ta2N are formed in this order. After the heating resistor layer 3 is patterned by photolithoetching, a feeder layer 4 is formed thereon and a second Si layer 8 is formed all over by sputtering, and thereon a heating resistor protective layer 5 of SiO2 and a wear resistant layer 6 of Ta2O5 are formed in this order. In this manner, a thermal head of a required construction is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermal head used in a thermal recording device or the like.

(Conventional technology) Conventionally, this type of technology has been developed by IEEE
RANSACTIONS ON COMPONENTS
, HYBRIDS.

AND MANUFACTURING TECHNOG
Y) VotCHMT-7A 3 (5EPTE Kowa R1984) P, 294-298. FIG. 2 shows the configuration of a conventional thin film type thermal head. This thermal head has a SiO2f surface! : A heating resistor layer 3 and a power supply layer 4 are formed on a substrate 1 having a heat insulating layer 2 of glaze as a main component, and on top of that, a heating resistor protective layer 5 of SiO2 and a wear-resistant layer 6 of Ta2 are formed.
05 layer is formed.

The reason why SiO2 is used as the protective layer 5 is that SiO2
has a great oxygen blocking effect and prevents high temperature heating elements from oxidizing. Another reason is that, since the coefficient of linear expansion of SiO2 is very small, thermal shock can be alleviated by pressing down on the heating resistor.

5102 +Ta as heating resistor protective layer and wear-resistant layer
205 is the most common combination, but SiC alone may be used instead.

(Problems to be Solved by the Invention) However, as described above, in the case of a thermal device having a heat insulating layer made of a material containing oxygen or a heat generating resistor layer protective layer on the lower surface or upper surface of the heating resistor layer, When using this thermal head at high power, there was a drawback that the heating resistor layer deteriorated.

This is considered to be because an interfacial reaction occurs due to high temperature between the heating resistor layer and the heat insulating layer or between the heating resistor layer and the heating resistor protective layer, or because the resistance layer deteriorates for some other reason.

The object of the present invention is to eliminate the above-mentioned problems and provide a high-performance thermal head that can be used with high power.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a substrate, a heating resistor layer, and at least one side of the upper surface side or the lower surface side of the heating resistor layer. and a layer made of a material containing oxygen as a constituent, wherein a thin Si layer is provided between at least one of the layers made of a material containing oxygen as a constituent and the heating resistor layer. It is something.

Examples of the layer made of the material containing oxygen as a constituent include a heat retaining layer provided on the lower surface side of the heat generating resistor layer and a heat generating resistor protective layer provided on the upper surface side of the heat generating resistor layer.

(Function) According to the present invention, between the heat generating resistor layer and the heat insulating layer made of a material containing oxygen as a constituent, or between the heat generating resistor layer and the heat generating resistor protective layer made of a material containing oxygen as a constituent. By providing a thin Si layer on at least one of the layers, deterioration of the heating resistor is suppressed when used in high temperatures.

This may be because this Si layer prevents the above-mentioned interfacial reaction between the heating resistor protective layer or heat insulating layer and the heating resistor layer at high temperatures, or it prevents the heating resistor layer from deteriorating in some way. This is thought to be due to the fact that

(Example) FIG. 1 is a sectional view of an embodiment of the present invention.

In this FIG. 1, the same parts as those in the above-mentioned FIG. 2 are given the same numbers. The thermal head shown in FIG. 1 is manufactured as follows.

First, a heat insulating layer 2 of a glaze mainly composed of SiO2 is formed on a substrate 1 made of ceramic or the like, a first Si layer 7 with a thickness of approximately 100X is formed on this heat insulating layer 2, and then a heat generating resistor layer 3 is formed. After forming Ta2N to a thickness of about 30.0 OX, the heating resistor layer 3 is photolithographically etched and A'-turned, and then the power supply layer 4 is formed thereon.

Next, a second Si layer 8 is deposited on the entire surface using the sintering method.
A heating resistor protective layer (hereinafter referred to as a protective layer) 5 of SiO2 with a thickness of about 2 μm and a T layer with a thickness of about 4 μm are formed on it.
Wear-resistant layer 6 of a205 is sequentially formed. In this way, a thermal head having the structure shown in FIG. 1 is completed.

FIG. 3 shows the results of a step stress test conducted on the thermal head according to the present invention and the conventional thermal head.

In FIG. 3, curve A shows all the characteristics of the thermal head according to the present invention, and curve B shows the characteristics of the conventional thermal head. This step stress test has a pulse width of 0.
8 ms, 5 ms repetition/? This was done using Luz.

As is clear from FIG. 3, the thermal head according to the present invention maintains sufficient stability even with large applied power. This shows that it can withstand use at high power.

This is because in the thermal head 9 according to the present invention, each of the 84 layers provided on the upper and lower surfaces of the heating resistor layer is a protective layer of SiO2 or a heat insulating layer of glaze mainly composed of 5j02 and the heating resistor layer. This is thought to be because it prevents the interfacial reaction at high temperatures and prevents the heating resistor layer from oxidizing, or because it prevents the heating resistor layer from deteriorating in some way.

In addition, the film thickness of each of the 84 layers in the above example is 100X
However, it has been found that even a very thin film of about 20 layers can perform the above-mentioned functions. It was also confirmed that the above-mentioned function can be achieved even when the film is relatively thick, about 1000X, but when the film becomes thicker than 500X, the 84-layer film itself functions as a resistive layer rather than an insulating layer. It is better to set the film thickness to 500X or less because there is a risk that the thermal head will start to function and deteriorate the performance of the thermal head.

Further, in the above-mentioned embodiment, the Si layer is provided over the entire upper and lower surfaces of the heat generating resistor layer, but it is sufficient to form each Si layer so as to include at least the heat generating portion of the heat generating resistor layer. It is.

Further, even if the 84 layer is formed only on either the upper surface or the lower surface of the heating resistor layer, a temporary effect can be obtained.In this case, of course, oxygen is formed on the side where the Si layer is formed. A protective layer or a heat-retaining layer made of a material contained as a component is provided.

Here, the materials for the substrate, the heat insulating layer, the heating resistor layer, the heating resistor protective layer, and the wear-resistant layer are not particularly limited to the materials shown in the above-mentioned embodiments. At203. as the material of the protective layer. Examples include oxides of Hf and oxides of Zr. In some cases, Ta205 mixed with SiO2 can be used as a wear-resistant layer and a heating resistor layer.

As for the method of forming the Si layer of the present invention, in addition to the sloping method, a vapor deposition method, a CVD method, etc. can also be used.

(Effects of the Invention) As described above in detail, according to the present invention, there is a space between the heat generating resistor layer and the heat insulating layer made of a material containing oxygen as a constituent, or between the heat generating resistor layer and the heat insulating layer made of a material containing oxygen as a constituent. At least one of the protective layer and the material K
By providing a Si layer, we can provide a thermal head that can be used at higher power than conventional thermal heads, and if used at the same power as conventional thermal heads, it will have a much longer life. It is possible to do so. In this way, it is possible to provide a thermal head that has a longer life and is capable of high-speed printing.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of a thermal head according to a first embodiment of the present invention, FIG. 2 is a sectional view showing the structure of a conventional thermal head, and FIG. 3 is a sectional view showing the structure of a thermal head according to the present invention and a conventional thermal head. FIG. 3 is a diagram showing the results of a step stress test of a thermal head. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Heat insulation layer, 3... Heat generating resistor layer, 4... Power supply layer, 5... Heat generating resistor protective layer, 6...
... Wear-resistant layer, 7... First Si layer, 8... Second
Si layer.

Claims (5)

[Claims] (1) In a thermal head that includes a substrate, a heating resistor layer, and a layer made of a material containing oxygen as a constituent on at least one of the upper surface side and the lower surface side of the heating resistor layer, A thermal head characterized in that a thin Si layer is provided between at least one of the layers made of the material contained as a constituent component and the heating resistor layer. (2) The layer made of a material containing oxygen as a constituent is a heat insulating layer of a glaze formed on the substrate, and the Si layer is provided between the heat insulating layer and the heating resistor layer. A thermal head according to claim 1. (3) The layer made of a material containing oxygen as a constituent is a heating resistor protective layer made of SiO_2 formed on the heating resistor layer, and the heating resistor protective layer and the heating resistor layer are 2. The thermal head according to claim 1, further comprising the Si layer therebetween. (4) The thermal head according to any one of claims 1, 2, and 3, characterized in that the Si layer is provided so as to contact only the heat-generating portion of the heat-generating resistor layer and its vicinity. . (5) The thermal head according to any one of claims 1, 2, 3, and 4, wherein the Si layer has a thickness of 20 to 500 Å.