JP2984017B2 - Glaze substrate for thermal head and method of manufacturing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a glaze substrate for a thermal head used for a facsimile, a thermal printer, or the like.

[Prior art] Conventionally, for example, a thermal head has been known as a printing mechanism of a facsimile or a thermal printer.
The thermal head uses a glaze substrate in which a glassy glaze layer is formed on a ceramic substrate.

As the glaze substrate, for example, as shown in FIG. 4 (a), a glaze layer is formed on a flat ceramic substrate P1.
It is known that a projection P3 is formed by arranging P2 in a strip shape, a heating element P4 is formed on the surface of the projection P3, and a conductive pattern P5 is wired on a ceramic substrate P1.

Further, as shown in FIG. 4 (b), it is known that a projection P9 is formed by covering the entire surface of a ceramic substrate P7 having a projection P6 with a glaze layer P8, and forming a projection P9. A heating element P10 is formed on the surface, and the flat plate portion P of the glaze layer P8 is formed.
11, a conductive pattern P12 is wired.

[Problems to be Solved by the Invention] However, the above-mentioned conventional technology has the following problems and is not yet sufficient.

That is, in recent years, there has been an increasing demand for refinement of equipment, and in the case where the projections P3 are formed by the glaze layer P2 on the flat ceramic substrate P1, when the glaze layer P2 is fired, The so-called "hike" where the ends shrink
This caused a problem in the linearity and dimensional accuracy of the projection P3. Furthermore, high precision is also required for the above-mentioned wiring, and the conventional technique of directly wiring the conductive pattern P5 on the rough ceramic surface P1 cannot achieve higher precision and homogenization. Has arisen.

In the case where the glaze layer P8 is formed on the ceramic substrate P7 having the projections P6, the smoothness is improved by covering the entire surface of the ceramic substrate P1 with the glaze layer P8, but the glaze layer P8 is softened during firing. As a result, there is a problem that the projection P9 is easily spread, and it is not always possible to form the projection P9 having a sufficient height and width and a clear shape.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a glaze substrate for a thermal head, which has a protruding portion having a suitable shape and can perform precise and uniform wiring, and a method for manufacturing the same.

[Means for Solving the Problems] The invention of claim 1 for solving such a problem is to provide a first glaze layer formed in a convex shape on a ceramic substrate and a temperature of 50 ° C. A second glaze layer having a low softening point and covering the first glaze layer or in contact with the first glaze layer and formed on the ceramic substrate. The glaze substrate for a thermal head to be used is a gist.

The invention according to claim 2 is that, after the first glaze layer is formed on the ceramic substrate by baking, the first glaze layer is covered with or in contact with the first glaze layer. 50 ° C from the glaze layer of
A thermal head characterized in that a composition to be a second glaze layer having a low softening point is formed on the ceramic substrate, and then fired at a temperature 100 ° C. or lower than the firing temperature of the first glaze layer. The gist is a method for manufacturing a glaze substrate for use.

Here, it is more preferable that the temperature difference of the softening point between the first glaze layer and the second glaze layer is 100 ° C. or more, since a convex portion having a distinct shape is formed.

As the ceramic substrate, alumina, aluminum nitride, silicon nitride, silicon carbide, mullite, or the like can be used.

[Operation] According to the first aspect of the present invention, the first glaze layer is formed in a convex shape on the ceramic substrate, and further covers the first glaze layer or contacts the layer to form the first glaze layer on the ceramic substrate. Since the second glaze layer having a softening point lower than that of the glaze layer by 50 ° C. or more is formed, the shape of the convex portion is clearly preserved without the first glaze layer being softened when the second glaze layer is fired. Is done.

According to the invention of claim 2, after the first glaze layer having a high softening point is formed in a convex shape on the ceramic substrate, the first glaze layer is formed.
By forming a second glaze layer having a softening point lower than that of the first glaze layer by 50 ° C. or more and firing at a temperature 100 ° C. or lower than the firing temperature of the first glaze layer, the two glaze layers react to cause devitrification. To prevent Further, since the firing temperature of the second glaze layer is considerably lower than the firing temperature of the first glaze layer, it is possible to prevent the first glaze layer from being softened by the firing, whereby the shape of the convex portion becomes clear. Will be saved.

[Embodiments] Each embodiment of the present invention will be described below. Here, in the first to third embodiments, a first glaze layer having a high softening point for forming a projection is provided on a ceramic substrate. Later, a second glaze layer having a low softening point was formed to a uniform thickness.

(1) First to Third Examples First, materials and the like used in these examples will be described.

As the ceramic substrate on which the first and second glaze layers are formed, a substrate containing 97% by weight of alumina is used. In addition, aluminum nitride, silicon nitride, silicon carbide, mullite, or the like can be used.

Further, the paste that becomes the first or second glaze layer is as follows:
First, a glass raw material is prepared so as to have a composition shown in Table 1 below, melted at 1300 ° C to 1500 ° C, and then rapidly cooled in water to produce a glass frit. Next, the glass frit is pulverized and mixed with an ethylcellulose-based binder to produce a paste.

In Table 1 below, sample No. 1 is a composition used for the first glaze layer, and samples Nos. 2 and 3 are compositions used for the second glaze layer. Sample No. 4 is a reference example usable for the first glaze layer, and sample No. 5 is a glaze composition used in a comparative example described later.

First Embodiment As shown in FIG. 1, a glaze substrate 31 used in a thermal head of the present embodiment is provided on a ceramic substrate 32.
The first glaze layer 33 having the composition of Sample No. 1 in Table 1 above was
The first glaze layer 33 and the ceramic substrate 32 are formed on the surfaces of the first glaze layer 33 and the ceramic substrate 32 in a convex shape with a width of 1.0 mm and a height of 50 μm. 34
Are formed. In the present embodiment, the protrusions are formed by the convex portions and the second glaze layer 34 formed thereon.
35 is formed.

In order to manufacture the glaze substrate 31, first, as shown in Table 2 below, the first
The paste of sample No. 1 to be the glaze layer 33 was applied in a convex shape and baked at 1250 ° C. for 2 hours. Next, on the surfaces of the first glaze layer 33 and the ceramic substrate 32, the above sample No. 2
Was applied in a uniform thickness and baked at 1020 ° C. for 2 hours.

The glaze substrate 31 manufactured in this manner includes a projection 35
Both the width and height of the first baking layer maintain the shape at the time of the first baking, and there is no devitrification at the contact portion between the first glaze layer 33 and the second glaze layer 34, and the surface is smooth and suitable for practical use. is there.

Second Embodiment As shown in FIG. 2, the glaze substrate 41 of this embodiment is
On the ceramic substrate 42, a projection 44 having a height of 50 μm and a width of 1.0 mm, made of a first glaze layer 43 having the composition of Sample No. 1, is formed. Then, the sample No. 3 having a uniform thickness of 30 μm was placed on the ceramic substrate 42 in contact with both side surfaces of the protrusion 44.
The second glaze layer 45 having the composition of FIG.

When the glaze substrate 41 is manufactured, as shown in Table 2 below, the first glaze layer 43 is formed at 1250 ° C.
After firing for 2 hours, the second glaze layer 45 was fired at 930 ° C. for 2 hours.

The glaze substrate 41 manufactured in this way is the first substrate.
The same operation and effect as those of the embodiment can be obtained.

Third Embodiment As shown in FIG. 3, the glaze substrate 51 of this embodiment is
On the ceramic substrate 52, a projection 54 having a height of 50 μm and a width of 1.0 mm and comprising a first glaze layer 53 having the composition of Sample No. 1 is formed. A second glaze layer 55 having a uniform thickness and a composition of Sample No. 2 is formed on the ceramic substrate 52 in contact with one side surface of the protrusion 54.

When manufacturing this glaze substrate 55, as shown in Table 2 below, the first glaze layer 53 is
After firing for 2 hours, the second glaze layer 55 was fired at 1020 ° C. for 2 hours.

The glaze substrate 51 manufactured in this manner is the first substrate.
The same operation and effect as those of the embodiment can be obtained.

In the present embodiment, when forming the second glaze layer 55, the same effect can be obtained by using the paste of the sample No. 3 and using the second glaze layer 55.

 Next, a comparative example will be described.

(Comparative Example) The glaze substrate (not shown) of the comparative example is the first substrate.
Although the configuration is almost the same as that of the embodiment, the composition of the material used is different.

That is, the first composition of Sample No. 1 was placed on the ceramic substrate.
A protrusion is formed by the glaze layer of No. 5, and a second glaze layer having the composition of Sample No. 5 is formed on the first glaze layer with a uniform thickness.

When manufacturing this glaze substrate, first, as shown in Table 2 below, the first glaze layer is
After firing at 2 ° C. for 2 hours, the second glaze layer was fired at 1150 ° C. for 2 hours.

The glaze substrate manufactured in this manner has a softening point Ts of the first glaze layer of 970 ° C. and a softening point Ts of the second glaze layer.
Since s is 940 ° C. and the temperature difference is 50 ° C. or less, the projection has a gentle hill shape and no clear projection is formed.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments at all, and it goes without saying that the present invention can be implemented in various modes without departing from the gist of the present invention.

[Effect of the Invention] According to the first aspect of the present invention, since the second glaze layer is formed on the first glaze layer, a convex portion having a clear shape is formed. Further, at that time, there is a feature that a convex portion having high linearity and accuracy is formed without sink marks.

In addition, by covering the surface of the ceramic substrate with the second glaze layer according to the first and second aspects, the surface roughness of the surface of the ceramic substrate can be significantly improved, thereby eliminating the need to perform surface processing on the ceramic substrate. Therefore, a glaze substrate for a thermal head having a smooth surface can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a glaze substrate according to a first embodiment of the present invention, FIG. 2 is a sectional view showing a glaze substrate according to a second embodiment,
FIG. 3 is a sectional view showing the glaze substrate of the third embodiment, and FIG.
The figure is a sectional view showing a conventional glaze substrate. 31,41,51 ... glaze substrate 32,42,52 ... ceramics substrate 33,43,53 ... first glaze layer 34,45,55 ... second glaze layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-42069 (JP, A) JP-A-62-153178 (JP, A) JP-A-63-79776 (JP, A) JP-A-2- 130155 (JP, A) JP-A-3-253352 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41J 2/335

Claims (2)

(57) [Claims] A first glaze layer formed in a convex shape on a ceramic substrate; and a first glaze layer having a softening point lower than that of the first glaze layer by at least 50 ° C. and covering or covering the first glaze layer. A glaze substrate for a thermal head, comprising: a second glaze layer disposed in contact with the glaze layer and formed on the ceramic substrate. 2. A first glaze layer formed on a ceramic substrate by baking the first glaze layer in a convex shape, and then covering the first glaze layer or in contact with the first glaze layer to form the first glaze layer. A composition for forming a second glaze layer having a softening point lower than that of the first glaze layer by 50 ° C. or more is formed on the ceramic substrate.
A method for producing a glaze substrate for a thermal head, characterized in that the glaze layer is fired at a temperature 100 ° C. or lower than the firing temperature of the glaze layer.