JPH07101093A - Glaze substrate of thermal head and production thereof - Google Patents

Abstract

PURPOSE:To obtain a partial glaze having high dimensional accuracy, reducing the short-circuit disconnection deficiencies of fine patterns and easy to form a resistor on the top part thereof CONSTITUTION:The glaze layer of an entire surface glaze substrate is removed over the range from the surface thereof to an insulating substrate by grinding or etching so as to leave a partial glaze layer forming scheduled area being the place where the partial glaze layer is formed and this glaze substrate is baked to form the partial glaze layer 11. A glass layer with a softening point of 700-900 deg.C is formed on the surface exposed by removing glaze of the insulating substrate in thickness of 5-20mum. Further, an exposed part where an electrode forming glaze layer 24 is not formed is provided to the end part of the partial glaze layer 11, that is, the boundary part of the partial glaze layer 11 and the electrode forming glass layer and the center of the partial glaze layer 11 is easily discriminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glaze substrate for a thermal head and its manufacturing method, and more particularly to a manufacturing method for efficiently manufacturing a glaze substrate for a thermal head having a partial glaze layer and a glaze substrate having a structure with improved yield.

[0002]

2. Description of the Related Art A thermal head is used in a thermal transfer printing apparatus and has a kind of heat storage layer called a glaze layer on an insulating substrate made of ceramic. A heat generating part made of a heat generating resistor is provided on the glaze layer. By providing the glaze layer, heat is not directly diffused into the ceramic substrate having high thermal conductivity, and energy efficiency is improved.

The glaze layer includes a partial glaze layer mainly used in a line printer and an entire glaze layer mainly used in a serial printer. In any case, an insulating substrate is used when a thermal head is manufactured. A product having a glaze layer provided thereon (glaze substrate) is prepared, and a predetermined electrode is formed on the glaze substrate. There are several types of glaze substrates.

FIG. 9 shows a typical partial glaze substrate (a substrate having a partial glaze layer). In FIG. 9, 11 is a partial glaze layer and 13 is an insulating substrate. In the partial glaze substrate according to this conventional example, only the convex partial glaze layer 11 is formed on the insulating substrate.

FIG. 10 shows another partial glaze substrate disclosed in Japanese Patent Publication No. 63-19358.
Unlike the conventional example described above, two types of partial glaze layers are formed on the insulating substrate. In this figure, 11 is a convex partial glaze layer (convex partial glaze layer), 13 is an insulating substrate, and 16 is a flat partial glaze layer (flat partial glaze layer). As is clear from this figure, in the glaze substrate according to this conventional example, two types of partial glaze layers, the convex partial glaze layer 11 and the flat partial glaze layer 16, are separately formed on the insulating substrate.

Unlike the conventional example of FIG. 10, FIG. 11 shows a full-glaze substrate having a full-glaze layer in which a flat glaze layer and a convex glaze layer are integrated on an insulating substrate. That is, in this conventional example, the entire surface of the insulating substrate 13 is covered with the glaze layer 11, and the glaze layer 18 has the convex portion 18b in a part of the flat portion 18a.

Substrate having a glaze layer (glaze substrate)
Can be formed by printing and baking glass glaze on a region to be formed on the insulating substrate 13, which is usually a ceramic substrate. Printing and drying of the glass glaze are repeated several times as needed. The method of manufacturing the partial glaze substrate will be described below.

The partial glaze substrate shown in FIG. 9 is 96
% Of Al ₂ O ₃ as a material on the insulating substrate 13, for example, a line-shaped glass glaze with a width of about 1 mm is screen-printed. Printing and drying of the glass glaze are repeated several times as needed. Finally, by firing this in a furnace at 1000 ° C. or higher, a partial glaze substrate having only the convex partial glazes 11 can be manufactured. On the other hand, the partial glaze substrate shown in FIG. 10 is produced by repeating printing and drying several times in the regions where the convex portion glaze 11 and the flat portion glaze 16 are to be formed, and then firing this in an oven at 1000 ° C. or higher. can do. The partial glaze substrate manufactured in this way has a thickness of about 35 μm to 70 μm.

On the other hand, a full-glaze substrate as shown in FIG. 11 is partially etched or ground from a full-glaze substrate having a full-glaze layer of uniform thickness to remove a part of the full-glaze layer. Then, it can be prepared by re-baking it. Specifically, a full-glaze layer having a thickness of, for example, 50 μm is formed on the entire upper surface of the insulating substrate 3 made of 96% Al ₂ O ₃ , and the whole-glaze layer is formed by leaving the place where the partial glaze layer is to be formed. A part of the entire glaze layer is removed by grinding or etching from the surface to a depth that does not reach the insulating substrate. Then, the substrate from which a part of the entire glaze layer has been removed is fired again at a temperature of 850 ° C. to 1200 ° C., so that the convex portion 1 having a desired width and height is obtained.
A whole-glaze substrate partially having 8b is obtained.

[0010]

Since the conventional method for manufacturing a partial glaze substrate is the method as described above, the method of forming a partial glaze layer by printing causes a partial glaze error due to a setting error at the time of printing. There has been a problem that the accuracy of the width, position and parallelism may deviate by about ± 40 μm. Further, in the case of the partial glaze substrate, a fine pattern (for example, a pattern having a line width of 10 μm and a space between lines of 10 μm) is directly formed on the base material of the insulating substrate having a low surface smoothness. As a result, short circuits and disconnection failures frequently occur, leading to a deterioration in yield.

On the other hand, in the method of grinding etching, the boundary between the convex portion glaze and the flat portion glaze is not known, and it is difficult to form resistance on the top of the partial glaze, and the curvature of the partial glaze depends on the firing temperature and grinding accuracy. However, the quality was not constant and the yield was poor.

The present invention has been made in order to solve the above problems, and it is possible to obtain a partial glaze substrate having a partial glaze of uniform quality and high accuracy, and to reduce short-circuit and disconnection defects. The purpose of the present invention is to obtain a partial glaze substrate whose resistance can be easily formed on the top of the partial glaze.

[0013]

In order to solve the above problems, a method of forming a partial glaze substrate according to the present invention is a method of forming a partial glaze of a full-glaze substrate by grinding or etching, and leaving a glaze. A feature is that a partial glaze substrate is manufactured by removing from the surface to the insulating substrate and re-baking. Also,
The glass layer having a softening point of 700 ° C. to 900 ° C. is formed on the exposed surface of the insulating substrate by removing the glaze from 5 to 20 μm. Further, a glass layer is not provided on a part of the boundary between the exposed substrate surface and the partial glaze portion.

That is, in the method of manufacturing a glaze substrate for a thermal head according to claim 1 of the present invention, the step of forming an entire glaze layer on the insulating substrate and the partial glaze layer formed on the insulating substrate are partially performed. A step of leaving a part of the glaze layer on the insulating substrate by removing, and a step of firing the remaining glaze layer to form a partial glaze layer on the insulating substrate. .

In the method of manufacturing a glaze substrate for a thermal head according to a second aspect, the step of forming an entire glaze layer on the insulating substrate and the partial removal of the entire glaze layer formed on the insulating substrate A step of leaving a part of the glaze layer on the insulating substrate, a step of forming an electrode forming glass layer on the insulating substrate exposed by the partial removal of the glaze layer, and a step of baking the entire substrate. And are included.

Further, in a glaze substrate for a thermal head according to claim 3 of the present invention, an insulating substrate and a partial glaze layer formed in a region to be formed on the insulating substrate,
And a glass layer for electrode formation, which covers a part of the partial glaze layer and forms an electrode thereon.

In a glaze substrate for a thermal head according to a fourth aspect of the present invention, an insulating substrate, a partial glaze layer formed in a region to be formed on the insulating substrate, and a part of the partial glaze layer are covered. An electrode forming glass layer on which an electrode is formed, and an exposed portion provided at an end portion of the partial glaze layer and at a boundary portion between the partial glaze layer and the electrode forming glass layer. .

[0018]

The manufacturing method of the present invention has a softening point of 800 ° C to 10 ° C.
A glaze substrate obtained by firing an amorphous glaze at 00 ° C. at 1000 ° C. or higher, leaving a glaze layer in a region where a partial glaze is to be formed, and using a mechanical method such as sandblasting or grinding, or a chemical method such as etching. , A part of the insulating substrate at the boundary part between the glaze layer and the glaze layer is removed, and therefore, in order to obtain a desired curvature, 900 ° C. to 1300 ° C.
Even if it is fired again at the temperature of, the width of the glaze does not change before and after firing, and depending on the processing method for removing the glaze,
The accuracy of the glaze width and position is determined, and the width tolerance is ± 0.025 mm or less in the processing by the sandblast method, and the position accuracy is ±
0.03 mm or less can be realized.

The softening point of the insulating substrate surface is 700 ° C. to 9 ° C.
The surface roughness of the insulating substrate is improved by baking the glass layer at 00 ° C. to a thickness of 5 to 20 μm, for example, 0.5.
A pattern short circuit occurs when patterning the entire μm film.
Less disconnection defects.

Further, by providing an exposed portion where the glass layer is not partially formed at the boundary between the partial glaze and the surface of the insulating substrate, the boundary between the partial glaze and the surface of the insulating substrate can be easily identified, that is, the center of the partial glaze, that is, The partial glaze vertex can be specified, and the resistor can be easily formed at the vertex with good printing efficiency.

[0021]

【Example】

 (1) First Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 21 denotes a region where the partial glaze layer is to be formed. In this embodiment, the glass glaze is fired to form the entire surface glaze layer 22 on the insulating substrate 13, and the entire surface glaze layer 22 is removed leaving the glass glaze in the planned formation region 21 (FIG. 2). The removal is performed by grinding or etching. A feature of this embodiment is that, as shown in the cross-sectional view of FIG. 2, the glass glaze other than the formation target region 21 and the insulating substrate 13 thereunder are removed together. After the glass glaze in the planned formation region 21 is left, the processed glaze substrate is fired again at 900 ° C to 1300 ° C.
Then, as shown in FIG. 3, the convex partial glaze layer 11 having a desired height and curvature and good processing accuracy is formed on the insulating substrate 1.
3 is formed on.

Specifically, in the method of manufacturing the partial glaze substrate according to this embodiment, first, 96% of A
The entire glaze layer 22 is formed on the insulating substrate 13 made of l ₂ O ₃ . Then, in order to leave only the formation planned region 21 which will become the convex partial glaze layer 11 in the future, the glaze layer other than the formation planned region 21 and a part of the insulating substrate 13 are ground or etched by a sand blast method or the like. Remove. Then, it is baked at 900 ° C to 1300 ° C. Here, if the baking is performed with the glaze layer left over the entire surface of the insulating substrate 13 (for example, the entire surface glaze substrate shown in FIG. 11) as in the conventional case, the partial glaze may spread or wavy during baking. Therefore, accurate partial glaze cannot be obtained. Further, since the partial glaze and the flat portion glaze are continuous, it is difficult to optically find the center (top portion) of the partial glaze, and thus it is difficult to form the resistor. Therefore, in the present embodiment, unlike the prior art, by removing a part of the insulating substrate 13 as well, the glass glaze other than the formation scheduled region 21 is completely removed from the insulating substrate 13.

Here, in the manufacturing method according to this embodiment, a part of the glaze layer and the insulating substrate is removed by grinding such as sandblasting or etching. As the sandblasting method, for example, a 100 μm-thick photosensitive film (for example, a dry film) is attached on the entire surface glaze layer 22 on the insulating substrate 13, and a range of the partial glaze width from the upper surface is shielded by a mask to expose it. , Glaze layer 2
2. Remove the film in the removed part. Then for example #
SiC or Al with a particle size of about 300 or a few μm
₂ O ₃ particles are jetted under high pressure from above. As a result, the glaze layer in the part without the film is scraped. This time,
Since the film itself is elastic, SiC or Al
Particles such as ₂ O ₃ are hard to be scraped, and serve as a mask for craze layer processing, and desired shape processing can be performed. Incidentally, in the glass etching method using hydrofluoric nitric acid, it is difficult that the resist material can withstand the desired etching time for the glaze layer, but it is difficult. However, in the sandblasting method, a dry film is used, so that the processing is easy.

Addition of Glass Layer for Electrode Formation As described above, in the method for manufacturing a partial glaze substrate according to the first embodiment of the present invention, the glass glaze other than the area 21 to be formed and the lower portion thereof are formed by grinding or etching. The insulating substrate 13 and the insulating substrate 13 are removed and re-fired to manufacture a partial glaze substrate having the convex partial glaze layer 11.

Here, conventionally, for example, as shown in FIG. 11, firing is performed with the glaze layer left over the entire surface of the insulating substrate 13 in order to form a lead electrode or the like on the entire glaze layer. Is. That is, when the glaze layer is not left, the lead electrode and the like are directly formed on the insulating substrate 13 having low smoothness, which causes a problem in accuracy.

In the embodiment, even the insulating substrate 13 is removed, and the insulating substrate 13 is inevitably exposed. However, it is avoided to directly form the lead electrode or the like on the insulating substrate 13. Therefore, as shown in FIG. 4, in addition to the convex partial glaze layer 11 as described above, the insulating substrate 1
A glass layer (electrode forming glass layer 24) for forming an electrode is formed on 3.

That is, in FIG. 4, an electrode forming glass layer 24 is formed adjacent to the convex portion glaze layer 11 on the insulating substrate 13, and leads are formed on the electrode forming glass layer 24. The electrode 25 is formed. Also, FIG.
[Fig. 5] is a view of the substrate of Fig. 4 seen from above before electrode formation.
As shown in FIG. 5, in the present embodiment, the convex partial glaze layer 1 is at the end of the convex partial glaze layer 11.
An exposed portion 27 that is not covered with the glass layer is provided at the boundary between the glass layer 24 for electrode formation and the electrode layer 1. This exposed part 2
7 is provided to make it easier to distinguish the boundary between the convex-shaped glaze layer 11 and the electrode forming glass layer 24. The shape of the exposed portion 27 is not limited to the quadrangular shape as shown in FIG. 5, and any shape that can be easily discriminated can be adopted.

In order to manufacture a glaze substrate having the electrode forming glass layer 24, a softening point 700 is formed on the surface of the insulating substrate 13 other than the convex-shaped glaze layer 11 where the lead electrode 25 is to be formed. The glass paste at a temperature of from 900 to 900 ° C. is printed and fired to form a glass layer having a thickness of 5 to 20 μm. This glass layer is formed so as to cover a part of the partial glaze. By doing so, the lead electrodes and the like are not directly formed on the insulating substrate 13 having low smoothness, and the problem of accuracy does not occur.

Quality evaluation of thermal head The surface roughness Ra of the insulating substrate 13 made of 96% Al ₂ O ₃ is 0.2 to 0.3 μm, but Ra = 0.05 by forming the glass layer. become. Then, the number of occurrences of short-circuiting / disconnection when a fine pattern is formed is reduced as shown in FIG.

Further, a glass layer having a film thickness of 5 to 20 μm is formed by leaving an edge portion of the convex partial glaze layer 11 and a part of a boundary portion between the convex partial glaze layer 11 and the electrode forming glass layer 24. Thus, the exposed portion 27 is formed. Then, as described above, the partial glaze and the substrate surface can be easily distinguished at the exposed portion 27, the partial glaze vertex (that is, the center) can be easily discriminated, and the resistor can be accurately formed on the partial glaze top. Therefore, a high quality thermal head can be obtained.

(2) Second Embodiment FIG. 7 is a sectional view showing a partial glaze substrate according to a second embodiment having a convex partial glaze layer 11, a flat partial glaze layer 16 and an electrode forming glass layer 24. Is. Although the convex partial glaze layer 11 is manufactured in the first embodiment, a partial glaze substrate having the flat partial glaze layer 16 can be formed only by widening the formation scheduled region 21 as compared with the first embodiment. When it is desired to adjust the thickness of the flat partial glaze layer 16, it can be easily performed by first adjusting the thickness of the entire surface glaze layer 22 formed on the insulating substrate 13.

(3) Third Embodiment In the above first and second embodiments, the method of manufacturing the partial glaze substrate under the heating resistor forming portion of the thermal head and the glaze substrate manufactured by the method have been described. The glaze substrate according to the third embodiment is characterized in that an alignment pattern 28 for aligning the patterns is provided, as shown in FIG. The alignment pattern 28 is
The partial glaze layer 11 is formed simultaneously with the formation of the partial glaze layer 11 on the insulating substrate 13 by the sun blast method. By thus providing the alignment pattern 28, for example, the alignment of the conductor pattern of the thermal head and the partial glaze, or the alignment of the partial glaze and the heating resistor can be automatically performed by pattern recognition. Therefore, the manufacturing yield of the thermal head can be improved. The alignment pattern 28 is not particularly limited, but the smaller the size, the higher the accuracy. Further, by providing the alignment patterns 28 at both ends of the insulating substrate 13 as shown in FIG. 8, it is possible to further reduce the deviation in parallelism, as compared with the case where the alignment patterns 28 are provided alone.

[0034]

As described above, according to the present invention, a part of the glaze layer is ground and removed up to the insulating substrate, so that a highly accurate partial glaze thermal head can be obtained.

Further, a softening point for covering a part of the partial glaze layer and forming an electrode thereon is 700 ° C. to 9 ° C.
Since the glass layer at 00 ° C. is formed to have a thickness of 5 to 20 μm, the surface roughness is improved and the short circuit disconnection defect of the pattern is reduced.

Further, since the exposed portion where the glass layer is not formed is provided at the end of the partial glaze layer and at the boundary between the partial glaze layer and the electrode forming glass layer, the center of the partial glaze layer can be easily identified. Therefore, the heat generating portion can be easily provided at a fixed position.

[Brief description of drawings]

FIG. 1 is a sectional view of a partial glaze substrate showing a first embodiment of the present invention, showing a state before removing a glass glaze.

FIG. 2 is a cross-sectional view of a partial glaze substrate before processing showing a first embodiment of the present invention, showing a state after the glass glaze and a part of the insulating substrate are removed.

FIG. 3 is a cross-sectional view of a partial glaze substrate before processing showing a first embodiment of the present invention, showing a state after the substrate of FIG. 2 is baked.

FIG. 4 is a cross-sectional view of a partial glaze substrate including an electrode forming glass layer.

FIG. 5 is a plan view of the substrate of FIG. 4 seen from above, before forming electrodes.

FIG. 6 is a diagram showing a comparison result of the numbers of occurrences of short circuit / disconnection defects of non-implemented products of the present invention.

FIG. 7 is a sectional view of a partial glaze substrate according to a second embodiment of the present invention.

8A and 8B are views showing a partial glaze substrate according to a third embodiment of the present invention, and particularly, FIG. 8A is a plan view and FIG.
8B is a sectional view taken along line I-I, and FIG. 8C is a sectional view taken along line II-II.

FIG. 9 is a cross-sectional view of a conventional partial glaze substrate.

FIG. 10 is a sectional view of a conventional partial glaze substrate.

FIG. 11 is a sectional view of a conventional partial glaze substrate.

[Explanation of symbols]

 11 Convex Partial Glaze Layer 13 Insulating Substrate 16 Flat Partial Glaze Layer 21 Planned Region 22 Full Surface Glaze Layer 24 Electrode Forming Glass Layer 25 Lead Electrode 27 Exposed Part 28 Positioning Pattern

Claims (4)

[Claims] 1. A step of forming an entire glaze layer on an insulating substrate, and a step of partially removing the entire glaze layer formed on the insulating substrate to leave a part of the glaze layer on the insulating substrate. And a step of firing the remaining glaze layer to form a partial glaze layer on the insulating substrate, the manufacturing method of the glaze substrate of the thermal head. 2. A step of forming an entire glaze layer on the insulating substrate, and a step of partially removing the entire glaze layer formed on the insulating substrate to leave a part of the glaze layer on the insulating substrate. A step of forming a glass layer for forming an electrode on an insulating substrate exposed by partially removing the glaze layer, and a step of baking the entire substrate; Production method. 3. An insulating substrate, a partial glaze layer formed in a region to be formed on the insulating substrate, and a glass layer for electrode formation which covers a part of the partial glaze layer and forms an electrode thereon. And a glaze board for a thermal head. 4. An insulating substrate, a partial glaze layer formed in a region to be formed on the insulating substrate, and a glass layer for electrode formation which covers a part of the partial glaze layer and forms an electrode thereon. A glaze substrate for a thermal head, comprising: an exposed portion provided at an end of the partial glaze layer and at a boundary portion between the partial glaze layer and the electrode forming glass layer.