JP3167347B2 - Manufacturing method of thermal print head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention is, among the thermal print head to be used for facsimile machines and various printers such as, in particular, as well as adapted to the printing for the surface roughness large so-called rough paper, the thermal print head adapted to high-speed printing It relates to a manufacturing method .

[0002]

2. Description of the Related Art In order to adapt a thermal print head to printing on rough paper having large surface irregularities and high-speed printing, the heat-generating portion must be as close as possible to the front end surface of an insulating substrate, and the heat-generating portion must be formed from the heat-generating portion. It is necessary to improve heat dissipation.

Therefore, a conventional thermal print head of this type is described in, for example, Japanese Patent Application Laid-Open No. 63-252756, and is configured as shown in FIGS.

That is, a glaze layer 2 is formed in a semi-cylindrical shape on a portion of the surface of an insulating substrate 1 made of ceramic adjacent to a front end surface 1a of the insulating substrate 1, and the surface of the glaze layer 2 and the insulating substrate 1 are formed. A resistance layer 3 in the form of a thin film is formed over the surface of
A large number of thin-film individual electrode bodies 4 are
Is formed so as to extend toward the front end face 1a of the insulating substrate 1, while the front end face 1 of the surface of the resistance layer 3 is formed.
In the portion adjacent to a, a common electrode body 5 in the form of a thin film is formed so that the common electrode body 5 extends along the front end surface 1a. And the common electrode body 5 constitute a heat generating portion 6;
Further, a heat radiating plate 7 made of a good conductor such as an aluminum alloy is arranged to be in close contact with the back surface of the insulating substrate 1.

Reference numeral 8 denotes a protective film made of glass or the like.

[0006]

However, in this conventional thermal print head, the common electrode body 5 exists in a portion between the front end surface 1a of the insulating substrate 1 and the heat generating portion 6, so that the above-described thermal print head has a problem. By reducing the dimension S from the distal end surface 1a to the heat generating portion 6 to bring each of the heat generating portions 6 closer to the distal end surface 1a, the width W of the common electrode body 5 must be reduced as a matter of course. However, since the electric resistance of the common electrode body 5 is increased and the voltage drop is increased, there is a problem that the method cannot be applied to those having a large number of heat generating portions 6, that is, a large number of dots.

The heat generated in each of the heat generating portions 6 escapes to the heat radiating plate 7 through the glaze layer 2 and the insulating substrate 1. The glaze layer 2 and the insulating substrate 1
Both are poor conductors of heat and have poor heat dissipation, so that there is a problem that their suitability for high-speed printing is low.

An object of the present invention is to provide a method for manufacturing a high-speed applicable type thermal print head which solves this problem.

[0009]

Means for Solving the Problems To achieve this technical problem
Therefore, the manufacturing method of the present invention is based on “one thermal print
Multiple units of the unit insulating substrate constituting the head are connected integrally
A good conductor such as silver or aluminum on the surface of
Subsequent to forming the layer, the surface of the heat conductive layer is
A laze layer is formed, and then a boundary between the unit insulating substrates is formed.
In the area of, crack the material body for each unit insulating substrate.
The groove for grinding is formed by the groove on the glaze layer.
And engraved at the depth reaching the material plate beyond the thermal conductor layer
Then, on the surface of the glaze layer, a thin-film resistance layer
Following the formation of
Forming a thin film-shaped individual electrode body, and further comprising:
On both left and right groove surfaces, a thin film common electrode body is
After forming along the direction, the material plate
Crack along each of the unit insulating substrates along the grooves.
To run. " .

[0010]

Operation and effect of the present invention
The thermal print head is made of silver on the surface of the insulating substrate.
Or a glaze layer with a thermally conductive layer such as aluminum
And forming the resistance layer on the surface of the glaze layer.
The individual electrode bodies are formed on the surface of the resistance layer of
Between the individual electrode bodies and the common electrode body.
The heat generated in each heat generating part in is passed through the glaze layer
The heat formed between the glaze layer and the insulating substrate.
The heat is transferred to the good conductor layer and the heat is
At the same time, the heat good conductor layer
Because it will also escape to the heat sink on the back,
Significant improvement in heat dissipation from the heat-generating part and, consequently, high-speed printing performance
And it is possible to improve
The tip of the insulating substrate is
The common electrode body is provided on this concave surface ,
The structure is formed so as to extend along the tip surface.
With this, the width dimension of the common electrode body is
Since it can increase in the thickness direction of the dose layer,
In a state where the width dimension of the common electrode body is secured, in other words,
Then, the width of the common electrode body is reduced.
Between the common electrode body and each of the individual electrode bodies.
Close each heating section to the front end surface of the insulating substrate.
Marks on rough paper with large surface irregularities
The character performance can be surely improved.

According to the manufacturing method of the present invention, the material body is provided with a groove for cracking the material plate for each unit insulating substrate.
The concave surface from the tip surface of the insulating substrate with respect to the glaze layer,
Since it can be molded simultaneously and a plurality of thermal print heads can be manufactured from one material plate, high-speed printing performance and high
This has the effect that a thermal print head having excellent printing performance can be manufactured at low cost.

[0012]

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

FIGS. 1 and 2 show an embodiment according to the present invention. In this figure, reference numeral 10 denotes a ceramic insulating substrate constituting one thermal print head A. The heat sink 11 made of aluminum alloy is in close contact.

A heat conductive layer 12 such as silver or aluminum is formed on the upper surface of the insulating substrate 10 to an appropriate thickness.
The glaze layer 1 having an appropriate thickness is formed on the upper surface of the heat conductive layer 12.
3, of the glaze layer 13 and the thermally conductive layer 12, the tip surface 10 of the insulating substrate 10.
a, the inclined concave surface 1 from the tip surface 10a.
4 is provided.

On the upper surface of the glaze layer 13, a thin-film resistance layer 15 is formed.
Further, on the upper surface of the resistance layer 15, a large number of thin-film individual electrode bodies 16 are formed such that the individual electrode bodies 16 extend toward the front end face 10a.

Further, the concave surface 1 of the resistance layer 15
On the surface of the portion 4, the common electrode body 1 also in the form of a thin film
7 is formed such that the common electrode body 17 extends along the distal end surface 10a, and a heat generating portion 18 is formed between the common electrode body 17 and each of the individual electrode bodies 16.

Reference numeral 19 denotes a protective film made of glass or the like.

As described above, the glaze layer 13 is formed on the upper surface of the insulating substrate 10 with the thermally conductive layer 12 such as silver or aluminum interposed therebetween, and the resistive layer 1 is formed on the upper surface of the glaze layer 13.
5 and furthermore, a large number of individual electrode bodies 16 are formed on the surface of the resistance layer 15, so that each heat generating portion 18 between each of the individual electrode bodies 16 and the common electrode body 17 is formed. The generated heat is transferred via the glaze layer 13 to the thermally conductive layer 12 formed between the glaze layer 13 and the insulating substrate 10, and is radiated from the thermally conductive layer 12 to the atmosphere. Since the heat escapes from the heat conductive layer 12 to the heat radiating plate 11 on the back surface via the insulating substrate 10, the heat radiation from each of the heat generating portions 18 can be greatly improved.

Further, in the glaze layer 13 and the thermal conductor layer 12, a portion of the insulating substrate 10 at the front end face 10 a is provided with an inclined recessed surface 14 from the front end face 10 a. Since the common electrode body 17 is formed so as to extend along the front end face 10a, the width of the common electrode body 17 can be increased in the thickness direction of the glaze layer 13. In a state where the width of the common electrode body 17 is ensured, in other words, without reducing the width of the common electrode body 17, each heat generating portion 18 between the common electrode body 17 and each of the individual electrode bodies 16 is formed. Therefore, the dimension S from the front end surface 10a to the tip surface 10a can be made smaller than in the conventional case.

The concave surface 14 from the tip surface 10a
Instead of being formed in an inclined shape, as shown in FIG. 3, it may be formed on a concave surface 14a substantially parallel to the front end surface 10a. By forming the recessed surfaces 14 and 14a so as to extend to the portion of the thermal conductor layer 12, the resistance layer 15 is formed.
And extending the common electrode body 16 to the portion of the heat conductive layer 12, while forming the heat conductive layer 16 of a good electric conductor such as silver or aluminum.
Is electrically connected to the thermal good conductor layer 16 which is a good electrical conductor. In other words, the thermal good conductor layer 1
6 can also be used as a common electrode body, so that there is an advantage that the voltage drop in the common electrode body 16 can be further reduced.

FIGS. 4 to 11 show an embodiment of a method for manufacturing the above-described thermal print head A. FIG.

First, as shown in FIG. 4, a material plate 20 in which a plurality (four in this embodiment) of unit insulating substrates 10 constituting one thermal print head A are integrally connected.
5 and 6, a heat conductive layer 12 of silver or the like is formed on the upper surface of the material plate 20 to an appropriate thickness, as shown in FIGS.
Next, the glaze layer 13 is formed on the upper surface of the heat conductive layer 12.
Is formed to an appropriate thickness.

The heat conductive layer 12 is formed by applying a silver paste to the upper surface of the material plate 20 to an appropriate thickness and then heating and firing the silver paste.

The glaze layer 13 is also formed by applying a glass paste to the upper surface of the heat conductive layer 12 to an appropriate thickness and then heating and firing the paste.

Next, as shown in FIG. 7 and FIG. 8, a V-shaped or U-shaped cross section for cracking the material plate 20 for each unit insulating substrate 10 is provided at the boundary between the unit insulating substrates 10. The slits 21 are formed in the material plate 2 so that the slits 21 exceed the glaze layer 13 and the heat conductive layer 12.
Engrave to a depth that reaches zero.

In this case, the right and left groove surfaces 21a, 21b of the groove 21 become the concave surfaces 14, 14a in FIGS. 1 and 3.

Then, on the upper surface of the glaze layer 13, as shown in FIG.
5 are both right and left groove surfaces 21a, 21b in the groove 21
Then, as shown in FIG. 10, a plurality of individual electrode bodies 16 are formed on the upper surface of the resistance layer 15, and both left and right grooves in the groove 21 of the resistance layer 13 are formed. The common electrode body 17 is formed on the surfaces of the surfaces 21 a and 21 b so as to extend along the groove 21.

Next, as shown by a two-dot chain line,
After forming a protective film 19 such as glass, the material plate 20
As shown in FIG. 11, by cracking each unit insulating substrate 10 at the location of each groove 21, a plurality of (four in this embodiment)
Can be manufactured.

[Brief description of the drawings]

FIG. 1 is an enlarged vertical sectional front view of a thermal print head according to a first embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is an enlarged vertical sectional front view of a thermal print head according to a second embodiment of the present invention.

FIG. 4 is a perspective view of a material plate.

FIG. 5 is a perspective view when a heat conductive layer and a glaze layer are formed on the material plate.

FIG. 6 is an enlarged sectional view taken along line VI-VI of FIG. 5;

FIG. 7 is a perspective view when a groove is cut.

FIG. 8 is an enlarged sectional view taken along line VIII-VIII of FIG. 7;

FIG. 9 is an enlarged cross-sectional view when a resistance layer is formed.

FIG. 10 is an enlarged sectional view when an individual electrode body and a common electrode body are formed.

FIG. 11 is an enlarged sectional view when the material plate is cracked for each unit insulating substrate.

FIG. 12 is an enlarged vertical sectional front view of a conventional thermal print head.

FIG. 13 is a plan view of FIG.

[Explanation of symbols]

 Reference Signs List A Thermal print head 10 Insulating substrate 10a Tip surface of insulating substrate 11 Heat sink 12 Thermally conductive layer 13 Glaze layer 14, 14a Depressed surface 15 Resistive layer 16 Individual electrode body 17 Common electrode body 18 Heating part 19 Protective film 20 Material board 21 Grooves 21a, 21b Both left and right groove surfaces of crease grooves

Claims (1)

(57) [Claims] 1. A method for manufacturing a thermal print head, comprising: forming a thermally conductive layer such as silver or aluminum on the surface of a material plate in which a plurality of unit insulating substrates constituting one thermal print head are integrally connected; A glaze layer is formed on the surface of the heat conductive layer, and then, at the boundary between the unit insulating substrates, a groove for cracking the material plate for each unit insulating substrate is formed. And engraving to a depth reaching the material plate beyond the heat conductive layer, and then, after forming a thin-film resistance layer on the surface of the glaze layer, a large number of wires are formed on the surface of the resistance layer. Form a thin film-shaped individual electrode body, further, on both left and right groove surfaces in the streak groove,
After the thin film common electrode body was formed so as to extend along the longitudinal direction of the streaks groove, the blank, the crease groove JP <br/> Features that cracking for each unit insulating substrate along the Method of manufacturing a thermal print head.