JPH11291532A - Thermal head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance print quality, print speed and lifetime of a thermal head significantly by making uniform the shape of a linear protrusion thereby enhancing contact between a recording medium and a heating element. SOLUTION: The thermal head comprises a substrate 10 having a protrusion, serving as a common electrode part 20, on the surface and formed by screen printing an insulating glass paste 26 on the common electrode part 20 and firing it at a specified temperature. Desired printing is performed by supplying a drive current to heating elements arranged on the substrate 10 based on a print data. The insulating glass paste 26 screen printed on the common electrode part 20 of the substrate 10 is dried and pressed with a knife type member 30 having a specified linear recess such that the longitudinal direction of glass paste 26 will be in parallel with the central axis of the linear recess. A desired linear shape is transferred to the insulating glass paste which is then shaped to produce a substrate 10 having a linear protrusion 70.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal head used in a thermal printer, and more particularly to an improvement in a preheat type and a double line type thermal head substrate.

[0002]

2. Description of the Related Art As a description of the prior art, a printing method of a thermal printer using a thermal head will be described. Next, the structure of the conventional thermal head will be described. It will be described in order. First, a printing method of a thermal printer using a thermal head will be described with reference to FIG. FIG. 6 is a side view showing a schematic configuration of a printing unit of a thermal printer main body (not shown). The outline of the printing method of a thermal printer is, for example, in the case of a thermal transfer type color thermal printer, an ink ribbon on which three primary colors of yellow, magenta, and cyan are repeatedly applied in order is heated, and each primary color is sequentially thermally transferred to printing paper. However, at the same time, if necessary, a heat treatment is performed after the thermal transfer of each primary color, so that a full-color image is finally printed.

As shown in FIG. 6, reference numeral 302 denotes a platen roller, which is sequentially rotated by a drive motor (not shown) by an angle corresponding to one line. Reference numeral 320 denotes printing paper, which is conveyed by the platen roller 302 one line at a time. 340 is a color ink ribbon,
The yellow ink, magenta ink, and cyan ink are repeatedly applied to the surface as described above.

[0004] These inks have the property of sublimating by applying gradation energy in addition to bias energy. Here, the bias energy refers to the energy required for each of the three color inks to start sublimation, and the gradation energy refers to the printing paper 320.
Means the energy for controlling the color density of the ink. Therefore, the sublimation rate of each ink is determined according to the applied gradation energy. Reference numeral 200 (100) denotes a thermal head having a plurality of heating resistors corresponding to one dot.
100 in parentheses is a preheat thermal head.
Hereinafter, similarly, the double line thermal head 200
The reference numerals related to the preheat thermal head 100 are written in parentheses, respectively. The thermal head 200 (100) applies energy generated by the supplied current to the color ink ribbon 340.

In the above-described configuration, as shown in FIG. 6, printing paper is formed by a linear projection 270 (170) containing a heating resistor (not shown) of a thermal head 200 (100) and a platen roller 302. 320 and the ink ribbon 340 are held at a predetermined pressure, and a predetermined heating resistor is heated at a predetermined energy based on print data from a host computer (not shown) to perform printing for one line. The platen roller 302 moves the ink ribbon 320 and the ink ribbon 340 by one line. By sequentially performing this process for each line, desired printing is performed on a predetermined area of the printing paper.

[0006] As a thermal head used in a color printer, the above-described single-line type thermal head is in practical use. However, from the viewpoint of increasing the printing speed, a preheat-type thermal head in which a single thermal head is improved to shorten the printing time is disclosed in Japanese Patent Application No. 8-300695. Further, the conventional double-line thermal head can print two lines of print data at the same time, and thus has the advantage of shortening the printing time, but has the problem of poor heat resistance. Therefore, a double line type thermal head which overcomes this problem and has excellent heat resistance is disclosed in Japanese Patent Application No. 8-313966.

The preheat thermal head and the double thermal head will be described with reference to FIGS. First, regarding the configuration of the preheat thermal head,
This will be described with reference to FIGS. 7 is a partially cutaway perspective view showing the external configuration of the preheat thermal head, and FIG. 8 is a vertical sectional side view taken along the line BB 'shown in FIG.

As shown in FIG. 7, a heat sink 102 efficiently radiates heat generated in each part of the preheat type thermal head 100 into the air. Reference numeral 110 denotes a stainless steel substrate, and a long common electrode portion 120 is formed on the surface of the stainless steel substrate 110. The common electrode section 120 is commonly connected to the heating resistors 130a1 to 130an and the heating resistors 130b1 to 130bn.

Heating resistors 130a1 to 130an, 13
0b1 to 130bn (hereinafter, "130a1 to 130b
n ". The same description may be given for other code numbers. ) Is the thermal head 1
A heat energy is generated to transfer a color printer (not shown) using a color printer 00 to paper. Reference numeral 180 denotes a connection flexible printed circuit board on which wiring for connection to a controller (not shown) of the printer body is formed.

Reference numeral 132 denotes a collective electrode, and the heating resistor 130
b1 to 130bn are connected to a transistor (not shown) that applies a voltage for energization at a time. 134a1
Reference numerals 134an to 134an denote individual lead electrodes, which are connected to a control IC which applies a voltage for energization to the heating resistors 130a1 to 130an (not shown). Reference numeral 122 denotes a glaze glass having a glaze 124 and a glaze 126.

As shown in FIG. 8, reference numeral 112 denotes a back glaze glass, which is applied and fired so that the stainless steel substrate 110 does not warp. 136 is an individual lead electrode 134a1-134an and a heating resistor 130a1-1.
The contact regions 138 that connect 30an with 30an, respectively,
A contact region 140 for connecting the heating resistors 130a1 to 130bn and the common electrode 120, 140 is a heating resistor 13
This is a contact region for connecting the collective electrode 132 with 0b1 to 130bn. Reference numeral 142 denotes a protective film, which is a heat-generating resistor 130a1 due to abrasion due to contact with paper during printing.
~ 130bn are protected. With this configuration, the heating resistor 13
The thermal energy generated at 0a1 to 130an is accumulated in the glaze glass 122, and this thermal energy is used as a part of the thermal energy when printing the next line. And the printing time can be shortened.

Next, the structure of the double line thermal head will be described with reference to FIGS. FIG.
FIG. 10 is a partially cutaway perspective view showing the external configuration of the double-line thermal head. FIG.
It is a line vertical side view. As shown in FIG. 9, this double-line type thermal head 200 includes, for example, a 0.8 mm-thick stainless steel substrate 210 like the preheat thermal head 100 shown in FIG. A long common electrode portion 220 is formed so as to protrude. The height of the common electrode 220 is 50 μm.
m. Reference numeral 212 denotes the stainless steel substrate 21
0 is a glaze glass formed on the back surface.

As shown in FIG. 10, first and second glaze glass layers 222 and 224 having raised portions 222a and 224a are formed near the left and right sides of the common electrode portion 220 on the stainless steel substrate 210. . Also, 2
Reference numeral 30 denotes a heating resistor, which is a second glaze glass 224 from the first glaze glass 222 via the common electrode unit 220.
Formed on each surface. This heating resistor 2
A plurality 30 are provided at regular intervals corresponding to one dot at the time of printing, and are electrically connected to the surface 220 a of the common electrode portion 220.

Reference numerals 232a1 to 232an denote first individual lead electrodes formed on the surface of the first glaze glass.
And is electrically connected. The other end of each of the first individual lead electrodes 232a1 to 232an is connected to a terminal of a first control IC (not shown). Similarly, 2
32b1 to 232bn are second individual lead electrodes formed on the surface of the second glaze glass, and one end thereof is electrically connected to the heating resistors 230a1 to 230an. The second individual lead electrodes 232b1-2
32bn is connected to a second control I (not shown).
It is connected to the C terminal.

Reference numeral 228 denotes a common electrode disposed along the common electrode portion 220 shown in FIG. 9, and the back surface thereof is electrically connected to the surface of the heating resistor 230 shown in FIG. 9 and is grounded. . That is, the portion of the heating resistor 230 that is not joined to the first individual lead electrodes 232a1 to 232an and the common electrode 228 actually acts as a heating resistor.
Hereinafter, this portion is referred to as first heating resistors 230a1 to 230a.
n. Similarly, a portion that is not joined to the second individual lead electrodes 232b1 to 232bn and the common electrode 228 actually acts as a heating resistor, and this portion is hereinafter referred to as second heating resistors 230b1 to 230bn. .

That is, the double line thermal head 200 shown in FIG.
and the second heating resistors 230b1 to 230bn. 242 shown in FIG. 10 is a protective film covering the entire surface of the first individual lead electrodes 232a1 to 232an and the like.
In FIG. 8, illustration of the protective film 242 is omitted.

Next, a method of manufacturing the above-described conventional double-line thermal head 200 will be described with reference to FIGS. The method of manufacturing the pre-heat type thermal head is the same as the method of manufacturing the double-line thermal head 200, and a description thereof will not be repeated. FIG. 10 shows a conventional double line thermal head 20.
0 is a longitudinal sectional side view showing a manufacturing process of No. 0. FIG.

First, a stainless steel substrate 210 shown in FIG.
After the cleaning process described in Japanese Patent Application No. 8-313966, dust or the like adhering to the front and back surfaces of the stainless steel substrate 210 is removed, and the front and back surfaces are polished by gentle etching.

When the polishing process is completed, the entire surface of the stainless steel substrate 210 is coated with a photoresist, and a mask is applied to a portion where the common electrode 228 is to be formed by photolithography. Photoresist patterning is performed. Thereby, the stainless steel substrate 21
At 0, the photoresist remains only in the portion where the common electrode portion 220 is to be formed.

Next, the stainless substrate 210 is immersed in an oxalic acid solution, a voltage of 5 V is applied between electrodes (not shown), and the unmasked portion of the stainless substrate 210 is etched. 220 is formed. Then, the stainless steel substrate 21
0 is fired, and an oxide film is formed on the surface of the stainless steel substrate 210.

When this firing is completed, as shown in FIG. 11, the first and second glass pastes 221 are provided on both left and right sides of the surface of the stainless steel substrate 210 from the common electrode portion 220.
a and 221b are screen printed. Here, the glass paste refers to a mixture of a solvent and glass powder. The first and second glass pastes 221a, 221a
When the screen printing of 1b is completed, these surfaces are leveled by leveling.

Next, after the above-mentioned leveling is completed, a pre-baking process is performed in which the stainless steel substrate 210 is heated to a relatively low temperature of 140 ° C. in a furnace. 140 ° C
The pre-baking is performed to volatilize the solvent contained in the glass paste gradually without bumping. When the pre-baking process is completed, the stainless steel substrate 210 is taken out of the furnace and cooled naturally to room temperature.

After that, the glass pastes 213a and 213b are screen-printed with a certain thickness on the back surface of the stainless steel substrate 210, and then the surfaces of the glass pastes 213a and 213b are flattened. When the flattening process is completed, a pre-baking process is performed in the same manner as described above, and the solvent contained in the glass paste is gradually volatilized.

After the pre-baking process, the stainless steel substrate 210 is baked at 850 ° C. for 10 minutes, and then naturally cooled to room temperature. As a result, as shown in FIG. 11, the first glass paste 221a and the second glass paste 221b become glaze glass 222, 224, respectively.
Then, the glass pastes 213a and 213b become glaze glasses 222a and 224a.

Next, using a metal mask, both side walls of the common electrode portion 220 shown in FIG.
A first partial glass paste and a second partial glass paste on each surface of the glaze glass of
Screen print each in μm. After the screen printing is completed, the surfaces of the first and second partial glass pastes are adjusted, and prebaking is performed.

When the pre-baking process is completed, the stainless steel substrate 210 is subjected to a baking process for 10 minutes in a furnace at a temperature of 950 ° C. Thereby, the first
8 and the second partial glass paste and the glass glaze thereunder are integrated, and as a result, the first and second glaze glasses 222 and 224 having a raised portion shown in FIG.
Is formed. Here, the surface including the common electrode portion 220 shown in FIG. 10 is polished as necessary. Thereby, the excess glass glaze and the oxide film on the surface of the common electrode portion 220 are removed.

Next, the stainless steel substrate 210 shown in FIG.
A first and a second glaze glass 222 formed thereon,
On each surface of the H.224, for example, a resistor film of TaSiO2 is formed by sputtering so as to have a predetermined resistance value. This resistor film is formed by electron beam evaporation.
For example, NiCr is deposited to a thickness of 0.1 μm.

Next, the heating resistors 230a1 to 230a1 shown in FIG.
Photoresist patterning is performed by photolithography according to the shape of 230bn. Then, by dipping the stainless steel substrate 210 in the cerium ammonium nitrate solution, the above-mentioned NiCr is etched using the above-mentioned photoresist pattern as a mask. Then, the photoresist is removed, whereby the NiCr is removed from the heating resistors 230a1 to 230bn.
Is patterned.

Next, the resistor film is etched using NiCr as a mask. Thus, the above-described resistor film is patterned into the shape of the heating resistors 230a1 to 230bn. Then, the heating resistors 230a1 to 230a
On the surface of bn, a binder thin film is formed with a thickness of 0.1 μm. This binder thin film is made of heat generating resistors 230a1-2.
30bn and first individual lead electrodes 232a1 to 232a
n, common electrode 228 and second individual lead electrode 232b
It plays a role of improving the adhesiveness between 1 and 232bn.

Next, the first heating resistors 230a1 to 230a23
An aluminum film is deposited on the surface of 0an by an electron beam deposition method. When this deposition is completed, the first and second
The first heating resistors 230a1 to 23023 corresponding to the individual lead electrodes 232a1 to 232bn and the common electrode 228 of FIG.
The photoresist is patterned by photolithography so that the photoresist remains on the surface of 0an.

Next, the stainless steel substrate 210 is immersed in an etching solution (phosphoric acid), whereby the first heating resistor 2 is formed.
The portions of the photoresist 30a1 to 230an other than the mask are etched. By removing the photoresist, the first and second individual lead electrodes 23 are removed.
2a1 to 232bn and the common electrode 228 are formed.
Next, the first and second individual lead electrodes 232a1 to 232
For example, SIALON (registered trademark) is coated on the entire surface of the bn and the first heating resistors 230a1 to 230an and the like to a thickness of 5 μm by sputtering, whereby a protective film is formed.

When this process is completed, the thermal head 200 shown in FIG. 9 is heat-treated at a temperature of 550 ° C. for one hour. Next, although not shown, first control ICs (not shown) in the first individual lead electrodes 232a1 to 232an shown in FIG. 9 are die-bonded. And each terminal of the first control IC;
The corresponding first individual lead electrodes 232a1 to 232a23
2an are respectively wire-bonded.

On the other hand, the second individual lead electrodes 232b1
An insulating film is deposited on the second IC area in the H.232bn. On the insulating film in the second IC area, each terminal of a second control IC (not shown) and a corresponding first terminal are provided. The two individual lead electrodes 232b1 to 232bn are respectively wire-bonded. Then, as a final step, the wire bonding portions of the first and second control ICs and the first and second individual lead electrodes 232a1 to 232a23
Part of 2bn is sealed with epoxy resin.

A double line type thermal head 20
In the case of No. 0, the stainless steel substrate 210 and the common electrode portion 220 can be formed of the same material with the same coefficient of thermal expansion through the above-described steps, so that the disconnection due to separation or the like due to the difference in coefficient of thermal expansion Can be reduced, and a thermal head with improved heat resistance can be obtained.

[0035]

In order to clarify the problems of the prior art, a conventional screen printing method will be described below with reference to FIGS. 12 to 14 and FIG. FIG. 12 is a cross-sectional side view of a screen printing mask used for screen printing on the substrate of the conventional thermal head, and FIG. 13 is a longitudinal side view showing the principle of screen printing. FIG. 14 is a vertical sectional side view for explaining a problem of a conventional method of manufacturing a thermal head substrate.

As shown in FIG. 12, a mask 400 for screen printing includes a mesh 402 and an emulsion layer 404. As shown in FIG. 13, a squeegee 440 having a glass paste 420 attached thereto is applied in a gap between screen-printing masks 400 provided on a stainless steel substrate 210 (110) while applying the glass paste 420 in the arrow direction. Screen printing by moving.

In this conventional screen printing method, the shape of the glass paste 420 depends on the shape of the mask 400 used, and the shape control is also defined by the total thickness of the mesh 402 and the emulsion 404 constituting the mask 400. Only shape control in the height direction is possible. That is, the three-dimensional shape control of the projection shape like the glass paste 420 is performed by controlling the viscosity of the glass paste 420 to control the shape change due to the influence of gravity in the leveling process. There was only.

On the other hand, the linear projection 270 (1) shown in FIG.
70) is a common electrode portion 220 (12) shown in FIGS.
0), heating resistors 230a1 to 230an, 230b1
~ 230bn (130a1 ~ 130an, 130b1 ~
130bn) and glaze glass 224a, 222a (1
24, 126). Therefore, since the three-dimensional shape of the linear projection 270 (170), which is common to the preheat thermal head and the double-line thermal head, is poor, the cross-sectional shape is upwardly convex. It was difficult to form a uniform linear projection 270 (170). for that reason,
Since the common electrode portion 220 is located near the center of the linear projection 270 (170) which is in direct contact with the ink ribbon or the printing paper, there is a problem that improvement in printing quality and printing speed cannot be expected. .

As described above, the glass paste 4
In the leveling step after the screen printing of No. 20, since the shape change due to gravity could only be indirectly controlled, the cross section of the linear projection 270 (170) having the common electrode 220 (120) in the middle is shown in FIG. As shown in (2), the insulating glass layer has a downwardly convex shape, which may cause disconnection when forming the resistor film, the electrode film, and the like. Further, due to its structure, screen printing tends to entrap air inside the glass paste 420 during printing, which causes surface defects of the fired glass glaze layer, causing disconnection and poor image quality. Therefore, the glass paste 42 after screen printing is used.
From 0, it is necessary to remove fine bubbles.

The present invention solves the above problems (problems),
The object of the present invention is to provide a thermal head in which the uniformity of the shape of the linear projections improves the uniformity of contact between the recording medium and the heating resistor, and greatly improves printing quality, printing speed and life. And

[0041]

According to a first aspect of the present invention, there is provided a thermal head including a projection formed on a surface of the thermal head and serving as a common electrode portion. A substrate formed by screen-printing an insulating glass paste on the electrode portion and firing at a predetermined temperature is provided, and a desired printing is performed by supplying a driving current to a heating resistor provided on the substrate based on print data. After the insulating glass paste screen-printed on the common electrode portion of the substrate is dried, a desired shape is transferred to the insulating glass paste using a member having a predetermined shape. Thereby, a substrate having a linear projection formed by shaping the insulating glass paste was provided.

[0042] The thermal head according to the second aspect has a projection serving as a common electrode portion formed on the surface, and is formed by screen-printing an insulating glass paste on the common electrode portion and baking it at a predetermined temperature. A thermal head having a substrate, and performing a desired printing by supplying a driving current to a heating resistor provided on the substrate based on print data, wherein a screen is printed on a common electrode portion of the substrate. After drying the insulating glass paste, a female member having a predetermined linear concave portion is pressed against the insulating glass paste so that the major axis direction of the insulating glass paste and the central axis of the linear concave portion are parallel. By transferring the desired linear shape to the insulating glass paste, a linear projection formed by shaping the insulating glass paste is formed. It was configured with a substrate to be.

According to the third aspect of the present invention, the thermal head has a projection serving as a common electrode portion formed on the surface, and is formed by screen-printing an insulating glass paste on the common electrode portion and firing at a predetermined temperature. A thermal head having a substrate, and performing a desired printing by supplying a driving current to a heating resistor provided on the substrate based on print data, wherein a screen is printed on a common electrode portion of the substrate. After drying the insulating glass paste, a female roll member having a predetermined concave cross-sectional shape formed along the peripheral surface is applied to the insulating glass paste, and pressed and rotated in parallel with the long axis direction of the insulating glass paste. By transferring the desired linear shape to the insulating glass paste, the insulating glass paste was shaped and formed. And configured to include a substrate having a linear projection portion.

According to a fourth aspect of the present invention, there is provided a thermal head having projections serving as common electrode portions formed on the surface thereof, and formed by screen-printing an insulating glass paste on the common electrode portions and firing at a predetermined temperature. A thermal head having a substrate, and performing a desired printing by supplying a driving current to a heating resistor provided on the substrate based on print data, wherein a screen is printed on a common electrode portion of the substrate. After drying the insulating glass paste, a cutting tool having a notch of a predetermined shape at the cutting edge is applied to the insulating glass paste, and is pressed and moved in parallel with the long axis direction of the insulating glass paste to obtain a desired linear shape. By transferring the shape to the insulating glass paste, a substrate having linear projections formed by shaping the insulating glass paste can be used. It was configured to obtain.

According to a fifth aspect of the present invention, there is provided a thermal head having a projection serving as a common electrode portion formed on the surface, the insulating head being formed by screen-printing an insulating glass paste on the common electrode portion and firing at a predetermined temperature. A thermal head having a substrate, and performing a desired printing by supplying a driving current to a heating resistor provided on the substrate based on print data, wherein a screen is printed on a common electrode portion of the substrate. After drying the insulating glass paste, a female slider having a groove with a predetermined cross-sectional concave portion formed on the bottom surface is applied to the insulating glass paste, and is pressed and moved in parallel with the long axis direction of the insulating glass paste. The cross-sectional shape is transferred to an insulating glass paste, and the insulating glass paste is shaped into a desired linear shape to form a linear shape. And configured to include a substrate having a raised portion.

In the thermal head according to the present invention, the insulating glass paste contains a thermoplastic agent that can be removed in a debinding step before sintering, and is applied to the surface of the insulating metal substrate heated to the thermoplastic temperature. By using a flat mold maintained at a temperature lower than the thermoplastic temperature as the female member, or using a roll-shaped mold maintained at a temperature lower than the thermoplastic temperature as the female roll Or, by using a metal blade maintained at a temperature lower than the thermoplastic temperature as the blade, or using a metal female slider maintained at a temperature lower than the thermoplastic temperature as the female slider And a substrate having a linear projection formed by shaping the insulating glass paste.

According to a seventh aspect of the present invention, the thermal head is configured such that an insulating substrate having a partial glaze at a linear projection formed by screen printing on the surface of alumina is used as the substrate.

[0048]

As described above, after the insulating glass paste is screen-printed and dried on the substrate of the thermal printer, the insulating glass paste is shaped using a predetermined member to form a linear projection. Since the cross-sectional shape of the linear projections can be made uniform and the bubbles in the insulating glass paste can be removed, the shape of the linear projections becomes uniform, and the contact between the recording medium and the heating resistor becomes uniform, and printing is performed. The quality and printing speed are greatly improved, and the life of the thermal head can be greatly extended. Also, when a removable thermoplastic agent is mixed into the glass paste and the surface of the stainless steel substrate is heated to the thermoplastic temperature, the glass paste is shaped by a member kept at a temperature lower than the thermoplastic temperature. Because the thermoplastic agent contained in the glass paste is maintained at the thermoplastic temperature, the transfer of the shape becomes easy, and because the shaping member is at or below the thermoplastic temperature, the transfer of the glass paste after the transfer shaping is performed. The shape can be kept stable, which further contributes to the uniform formation of the cross-sectional shape of the linear projection.

[0049]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a thermal head according to the present invention will be described with reference to FIGS. FIG. 1 is a vertical sectional side view for explaining a manufacturing process of a stainless steel substrate 10 used for a thermal head of the present invention. 2 to 5
Is a stainless steel substrate 1 used for the thermal head of the present invention.
FIG. 7 is a perspective view showing a state in which the same steps for manufacturing the same are formed by different means. The process of manufacturing the stainless steel substrate 10 used in the thermal head of the present invention is performed, for example, in the same manner as the above-mentioned conventional one, by, for example, having a thickness of 1 mm,
And a stainless steel substrate 10 containing 0.1 to 6.0% of Al, as described in paragraphs [0018] to [0022],
Cleaning processing, polishing processing, etching processing, baking, screen printing of glass paste, flattening of glass paste, and pre-baking processing are performed.

That is, the stainless steel substrate 10 is degreased and washed with an organic solvent such as acetone, and then washed with a scrubber. Thus, dust and the like adhering to the front and back surfaces of the stainless steel substrate 10 are removed. Next, the entire surface of the stainless steel substrate 10 is coated with a photoresist, a portion where a common electrode portion is to be formed is masked, and the photoresist is patterned by photolithography. As a result, the photoresist remains only on the portion of the stainless steel substrate 10 where the common electrode portion 20 is to be formed.

Next, the stainless steel substrate 10 is made of H 2 C 2 O 4
After being immersed in an oxalic acid solution of 2H2O: 200g + H2O: 200ml, the electrode interval (not shown) was set to 20 mm
A voltage of 5 V is applied between the electrodes. This allows
At an etching rate of about 0.67 μm / min, the portion of the stainless steel substrate 10 where no mask is applied is etched. As a result, a portion that is not etched remains as the common electrode portion 20. When the width of the common electrode unit 20 is wider than a target value in a state where the height of the common electrode unit 20 is a desired height, both sides of the common electrode unit 20 are polished with a grindstone.

Next, the stainless steel substrate 10 was heated at 900 ° C.,
Oxidation heat treatment for 0 min.
On the surface of No. 0, a dense oxide film is formed. Thereafter, a crystalline glass paste (insulating glass paste) 26 is screen-printed with a thickness of 20 μm on the surface having the common electrode portion 20 for shaping the crystalline glass glaze 24 shown in FIG. When the screen printing of the crystalline glass paste 26 is completed, these surfaces are flattened by leveling.

After the pre-baking process is completed, the solvent contained in the insulating glass paste is volatilized, the glass paste 26 is dried, and the stainless steel substrate 10 is cooled by natural air. This glass paste 26 screen-printed on the surface
Is ready to be removed and shaped. The following four methods are conceivable as a method of transferring the shape to the glass paste 26 using a member and forming the shape of the glass paste 26 into a desired shape.

First, as shown in FIG. 2, in order to form the glass paste 26 into a desired shape, a plate-shaped female member 30 having a linear concave shape at the bottom is inserted into the long length of the glass paste 26. By pressing the axial direction and the central axis of the linear concave shape formed in the female member 30 so as to be parallel, and transferring the linear concave shape to the glass paste 26,
The glass paste 26 is formed into a desired linear shape.

Second, as shown in FIG. 3, the peripheral surface 40a
Is applied so as to accommodate the glass paste 26, and the female roll member 40 is pressed and rotated in parallel with the long axis direction of the glass paste 26. By doing
By transferring the shape so that the cross-sectional shape of the glass paste 26 matches the shape of the cross-sectional concave portion formed on the peripheral surface 40a of the female roll member 40, the glass paste 26 is formed into a desired linear shape.

Third, as shown in FIG. 4, a cutting tool 50 having a notch of a desired shape is applied to the cutting edge 50a so as to sandwich the glass paste 26, and pressed in parallel to the longitudinal direction of the glass paste 26. While transferring, the shape of the notch portion is transferred to the glass paste 26,
The glass paste 26 is formed into a desired linear shape.

Fourth, as shown in FIG. 5, a female slider having a groove formed on the bottom surface 60a and having a desired sectional concave shape is applied to the glass paste 26, and is parallel to the longitudinal direction of the glass paste 26. The glass paste is formed into a desired linear shape by transferring the cross-sectional concave shape of the groove to the glass paste 26 by moving the glass paste while pressing it.

In these cases, the glass paste 26
Then, a flat metal plate kept at a temperature lower than the thermoplastic temperature is mixed with a thermoplastic agent that can be removed in a subsequent step of debinding, and the surface of the stainless steel substrate 10 is heated to the thermoplastic temperature. As the female member 30, or a roll-shaped die maintained at a temperature lower than the thermoplastic temperature as the female roll member 40, or a blade maintained at a temperature lower than the thermoplastic temperature as the blade If a female slider maintained at a temperature lower than the thermoplastic temperature is used as the female slider 60, the thermoplastic agent contained in the glass paste 26 is maintained at the thermoplastic temperature. Since the transfer of the shape is facilitated, and the female member 30 or the female roll member 40 or the blade 50 or the female slider 60 is set at a thermoplastic temperature or lower, respectively. The shape of the glass paste 26 after transfer to can be kept stable, it is possible to improve the uniformity of the shape of straight projections 70.

After the shaping of the glass paste 26 is completed,
Similar to the steps of the related art described in the above paragraph numbers [0023] to [0033], in the furnace, the stainless steel substrate 10 is baked at 900 ° C. for 10 minutes, and then cooled to room temperature. In addition, as described above, when a thermoplastic agent is mixed in the glass paste 26, in the furnace,
Before baking the stainless steel substrate 10 at 900 ° C. for 10 minutes, it is necessary to perform a binder removal step of heating and removing the thermoplastic agent under a reduced-pressure atmosphere and further in a stream of hydrogen. In this step, the insulating glass paste 26 becomes the crystalline glass layer 22 having fine irregularities on the surface.

Next, in order to form the glaze glass layer 22 shown in FIG.
4, the surface of the glaze glass paste 26 is formed. This glaze glass paste 26 has a melting point lower by about 100 ° C. than that of the crystalline glass layer 24. Then, similarly to the formation of the crystalline glass layer 22, the solvent contained in the glass paste is gradually evaporated and dried by prebaking at 150 ° C. without bumping. When the pre-baking is completed, the glass paste is shaped by any of the methods described in paragraphs [0054] to [0057], and baked in a furnace at 850 ° C. for 10 minutes.
If necessary, paragraph numbers [0058] and [005]
9]. This allows
A glaze glass 28 composed of the crystalline glass layer 22 and the glaze glass layer 24 is formed.

Further, the common electrode portion 20 is formed by lapping.
By removing the oxide film formed on the surface of the substrate, it is possible to finally obtain a thermal head including the thermal head substrate 10 of the present invention having the linear projections 70 having a uniform cross-sectional shape.

Therefore, as described above, a step of forming a screen-printed glass paste into a desired shape by using a member having a predetermined shape is added to the conventional manufacturing process of a thermal head substrate. The reproducibility and uniformity of the shape of the linear projections of the thermal head substrate are improved, and a thermal head having improved printing quality and printing speed can be obtained.

[0063]

As described above, the thermal head of the present invention has the following excellent effects because it is configured as described above. (1) As described in claim 1, after drying the insulating glass paste screen-printed on the common electrode portion of the substrate, the desired shape is transferred to the insulating glass paste using a member having a predetermined shape. By providing a substrate having a linear projection formed by shaping the insulating glass paste, the cross-sectional shape of the linear projection can be made uniform and bubbles in the insulating glass paste can be removed. Therefore, the shape of the linear projection becomes uniform, the contact between the recording medium and the heating resistor becomes uniform, and the printing quality,
The printing speed is greatly improved, and the life of the thermal head can be greatly extended. In this case, as the member having the predetermined shape, specifically, the member described in claims 2 to 5 may be used. (2) In addition, the glass paste is shaped by a member kept at a temperature lower than the thermoplastic temperature while a removable thermoplastic agent is mixed with the glass paste and the surface of the stainless steel substrate is heated to the thermoplastic temperature. By doing so, the transfer of the shape is facilitated because the thermoplastic agent contained in the glass paste is maintained at the thermoplastic temperature, and also, since the shaping member is at or below the thermoplastic temperature, after the transfer shaping, The shape of the glass paste can be kept stable, which further contributes to the uniform formation of the cross-sectional shape of the linear projection.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view for explaining a manufacturing process of a thermal head of the present invention.

FIG. 2 is a perspective view showing one step of a manufacturing process of the thermal head of the present invention.

FIG. 3 is a perspective view showing one step of a manufacturing process of the thermal head of the present invention.

FIG. 4 is a perspective view showing one step of a manufacturing process of the thermal head of the present invention.

FIG. 5 is a perspective view showing one step of a manufacturing process of the thermal head of the present invention.

FIG. 6 is a side view showing a schematic configuration of a printing unit of a thermal printer using a conventional thermal head.

FIG. 7 is a partially cutaway perspective view showing an external configuration of a conventional preheat thermal head.

8 is a vertical sectional side view taken along line BB 'shown in FIG.

FIG. 9 is a partially cutaway perspective view showing an external configuration of a conventional double-line thermal head.

FIG. 10 is a vertical sectional side view taken along line CC ′ shown in FIG. 9;

FIG. 11 is a vertical sectional side view for explaining a manufacturing process of a conventional double-line thermal head.

FIG. 12 is a vertical sectional side view of a mask used for screen printing.

FIG. 13 is a vertical sectional side view showing the principle of screen printing.

FIG. 14 is a vertical sectional side view for explaining a problem of a conventional method for manufacturing a thermal head substrate.

[Explanation of symbols]

 10: Thermal head substrate 20: Common electrode part 26: Insulating glass paste 28: Insulating glass 30: Female member 40: Female roll member 40a: Peripheral surface 50: Blade 50a: Blade edge 60: Female slider 60a: Bottom 70: Straight protrusions 130a1 to 130bn: Heating resistor 230a1 to 230bn: Heating resistor

Claims (7)

[Claims] A substrate formed by screen-printing an insulating glass paste on the common electrode portion and firing at a predetermined temperature, wherein the substrate has a projection serving as a common electrode portion formed on the surface; A thermal head configured to perform desired printing by supplying a driving current to a heating resistor provided on the substrate based on the insulating glass paste that is screen-printed on the common electrode portion of the substrate; By transferring a desired shape to the insulating glass paste by using a member having a predetermined shape, a substrate having a linear projection formed by shaping the insulating glass paste is provided. Thermal head. And a substrate formed by screen-printing an insulating glass paste on the common electrode portion and firing at a predetermined temperature, the substrate having a projection serving as a common electrode portion formed on the surface. A thermal head configured to perform desired printing by supplying a driving current to a heating resistor provided on the substrate based on the insulating glass paste that is screen-printed on the common electrode portion of the substrate; By pressing a female member having a predetermined linear concave portion against the insulating glass paste so that the major axis direction of the insulating glass paste and the central axis of the linear concave portion are parallel to each other, the desired linear shape is obtained. By transferring the shape to the insulating glass paste, it is possible to provide a substrate having a linear projection formed by shaping the insulating glass paste. The thermal head according to symptoms. 3. A substrate having a projection which becomes a common electrode portion formed on the surface, and is formed by screen-printing an insulating glass paste on the common electrode portion and baking it at a predetermined temperature. A thermal head configured to perform desired printing by supplying a driving current to a heating resistor provided on the substrate based on the insulating glass paste that is screen-printed on the common electrode portion of the substrate; By applying a female roll member having a predetermined cross-sectional concave shape formed along the peripheral surface to the insulating glass paste and pressing and rotating the insulating glass paste in parallel with the long axis direction of the insulating glass paste, a desired linear shape is obtained. Is transferred to the insulating glass paste,
A thermal head comprising a substrate having a linear projection formed by shaping the insulating glass paste. 4. A substrate having a projection serving as a common electrode portion formed on the surface, a substrate formed by screen-printing an insulating glass paste on the common electrode portion and firing at a predetermined temperature. A thermal head configured to perform desired printing by supplying a driving current to a heating resistor provided on the substrate based on the insulating glass paste that is screen-printed on the common electrode portion of the substrate; A desired linear shape is transferred to the insulating glass paste by applying a cutting tool having a cutout of a predetermined shape to the insulating glass paste, and pressing and moving the cutting tool in parallel with the long axis direction of the insulating glass paste. Thus, a substrate having a linear projection formed by shaping the insulating glass paste is provided. The thermal head. 5. A substrate having a projection serving as a common electrode portion formed on a surface thereof, and a substrate formed by screen-printing an insulating glass paste on the common electrode portion and firing at a predetermined temperature. A thermal head configured to perform desired printing by supplying a driving current to a heating resistor provided on the substrate based on the insulating glass paste that is screen-printed on the common electrode portion of the substrate; A female slider having a groove having a predetermined cross-sectional concave portion formed on the bottom surface is applied to the insulating glass paste, and the insulating glass paste is pressed and moved in parallel with the long axis direction thereof, thereby changing the cross-sectional shape to the insulating glass paste. The substrate having a linear projection formed by transferring and shaping the insulating glass paste into a desired linear shape is provided. A thermal head, characterized in that. 6. The insulating glass paste contains a thermoplastic agent that can be removed in a binder removal step before sintering, and the temperature of the insulating metal substrate heated to the thermoplastic temperature is lower than the thermoplastic temperature. By using a flat mold kept at the above as the female member, or by using a roll mold kept at a temperature lower than the thermoplastic temperature as the female roll, or By shaping and forming an insulating glass paste by using a metal blade maintained at a lower temperature as the blade, or by using a female female slider maintained at a temperature lower than the thermoplastic temperature as the female slider. The thermal head according to any one of claims 2 to 5, further comprising a substrate having a linear projection formed as described above. 7. The substrate according to claim 1, wherein an insulating substrate having a partial glaze at a linear projection formed by screen printing on the surface of alumina is used as the substrate.
7. The thermal head according to any one of claims 1 to 6.