JPH06238932A - Thermal head and its manufacture - Google Patents

Abstract

PURPOSE:To improve heating efficiency and printing quality by avoiding heat generated from a heating element from radiating to other parts by a method wherein in a thermal head in which a heating resistor is formed between respective feed elements on a non-conductor, and heat is generated by impressing a voltage to the heating resistor, space is formed between the non-conductor and a substrate. CONSTITUTION:A plurality of sets of feed elements 23a, 23b are formed on a substrate. One side of each set constitutes a lead electrode, and the other side constitutes a common electrode. Further, non-conductors 24a, 24b are integrally formed between the feed elements 23a, 23b of each set, and the feed element 23a is electrically insulated from the feed element 23b. Then, a heating resistor 29 is formed between respective feed elements 23a, 23b on the non- conductors 24a, 24b, and heated by impressing a voltage to the heating resistor 29. In such a case, space 26 is formed between the non-conductors 24a, 24b and the substrate. Thereby, heat which the heating resistor 29 generates is not radiated to other parts to improve heating efficiency, and printing quality is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal head and its manufacturing method.

[0002]

2. Description of the Related Art Conventionally, a thermal printer has a thermal head, and printing is performed by selectively applying a voltage corresponding to print data to a plurality of heating resistors of the thermal head. Further, there is provided a thermal head in which heat generated by each heating resistor is easily transmitted to a printing surface of a thermal recording paper or a thermal transfer ink ribbon (see Japanese Patent Laid-Open No. 3-247467).

FIG. 2 is a schematic view showing the structure of a conventional thermal head. In the figure, 11 is a substrate made of an insulating material such as alumina, and 12 is a heat insulating layer formed in a band shape on the substrate 11 and having a semicircular cross section. The heat insulation layer 12
Is formed of glaze glass or the like. Then, on the heat retaining layer 12, power supply bodies 13a and 13b, one of which constitutes a lead electrode and the other of which constitutes a common electrode, are formed. In addition, similarly, the power supply body 13a on the heat insulation layer 12,
The non-conductor 14 is formed between 13b, and the power feeding bodies 13a, 13
b and the non-conductor 14 form an integral layer.

Then, tantalum nitride (T) is deposited on the power supply members 13a and 13b and the non-conductor 14 by a sputtering method.
a ₂ N) and a heating resistor layer 15 is further formed,
The heating resistor layer 15 serves as a heating resistor between the power feeding members 13a and 13b. Then, the heat generating resistor layer 15 is coated with silicon oxide (SiO ₂ ) or the like by the sputtering method to form the protective layer 16.

In this case, the feeders 13a and 13b and the non-conductor 14 are formed as follows. That is, an aluminum layer is formed on the substrate 11 on which the heat retaining layer 12 is formed by a sputtering method or the like, then a photoresist is applied to the aluminum layer, and the photoresist is exposed using a glass mask or the like. Develop to form a resist pattern. Next, a non-conductor treatment is applied to the exposed portion of the aluminum layer.

The deconductoring treatment is performed by subjecting the aluminum layer to anodizing treatment. In this case, the aluminum layer on which the resist pattern has been formed is dipped in an oxalic acid solution. After applying the anodizing treatment, the photoresist is removed. At this time, the portion not subjected to the anodizing treatment is the power feeding body 13
The portions a and 13b, which have been subjected to the anodizing process, become the non-conductor 14.

The non-conductor 14 is formed in the vicinity of the apex of the heat retaining layer 12, and directly contacts the printing surface of the thermal recording paper (not shown) or the thermal transfer ink ribbon (not shown) during printing.
The glaze glass forming the heat retaining layer 12 is formed by a printing technique, and the firing temperature at that time is about 800.
[° C]. Therefore, the maximum temperature of the heating resistor when printing with the thermal head is set to 800 [° C] or less.

[0008]

However, in the above-mentioned conventional thermal head, the heat insulating layer 12 is formed of glaze glass, and since the heat conductivity of the glaze glass is high, the heat generated by the heating resistor is not generated. Insulation layer 1
2 is dissipated to other parts via 2, and the heat generation efficiency is reduced accordingly.

Further, since the printing technique is used when forming the heat retaining layer 12, there is a large variation in size and thickness,
Further, when printing is performed by thermal transfer using rough paper having a low surface smoothness, the paper contact is poor and the printing quality is degraded. SUMMARY OF THE INVENTION It is an object of the present invention to provide a thermal head capable of solving the problems of the conventional thermal head, improving heat generation efficiency, and improving printing quality, and a manufacturing method thereof.

[0010]

To this end, in the thermal head of the present invention, a plurality of sets of power feeding members are formed on the substrate, one of each set forming a lead electrode and the other forming a common electrode. . Further, a non-conductor is integrally formed between the power feeding bodies of each set to insulate the power feeding bodies from each other. Then, a heating resistor is formed between each pair of power feeding bodies on the non-conductor, and heat is generated when a voltage is applied. In addition, a space is formed between the nonconductor and the substrate.

In another thermal head of the present invention,
A heat retaining layer is formed on the substrate, and a plurality of sets of power supply members are formed on the substrate and the heat retaining layer. Then, a non-conductor is integrally formed on each heat-insulating layer between the power-supplying bodies of each set to insulate the power-supplying bodies from each other, and a heating resistor is formed on the non-conductor. In this case, a space is formed between the nonconductor and the heat insulating layer.

In the method for manufacturing a thermal head of the present invention, a resist pattern is formed on a substrate, a conductor metal layer is formed on the substrate and the resist pattern, and the conductor metal layer is cut, The resist pattern is removed to form a space between the conductor metal layer and the substrate, and the resist pattern is formed in a portion corresponding to the power feeding body. Then, the exposed portion of the conductor metal layer is subjected to a non-conducting treatment to form a non-conductor between the power feeding bodies, and a heating resistor is formed on the non-conductor.

[0013]

According to the present invention, as described above, in the thermal head, a plurality of sets of power feeding members are formed on the substrate, one of each set constitutes a lead electrode, and the other constitutes a common electrode. Further, a non-conductor is integrally formed between the power feeding bodies of each set to insulate the power feeding bodies from each other. Then, a heating resistor is formed between each pair of power feeding bodies on the non-conductor, and heat is generated when a voltage is applied.

Therefore, when the voltage corresponding to the print data is applied, the heating resistor generates heat and prints. In this case, since the space is formed between the non-conductor and the substrate, the heat generated by the heating resistor is not dissipated to other portions, and the heat generation efficiency is improved. In another thermal head of the present invention, a heat retaining layer is formed on the substrate, and a plurality of sets of power supply members are formed on the substrate and the heat retaining layer. Then, a non-conductor is integrally formed on each heat-insulating layer between the power-supplying bodies of each set to insulate the power-supplying bodies from each other, and a heating resistor is formed on the non-conductor.

In this case, since the space is formed between the non-conductor and the heat retaining layer, the heat generated by the heat generating resistor is not dissipated to other portions through the heat retaining layer, and the heat generating efficiency is improved. To do. In the method for manufacturing a thermal head of the present invention, a resist pattern is formed on the substrate, and a conductor metal layer is formed on the substrate and the resist pattern. At this time, a semi-cylindrical portion is formed on the conductor metal layer by the resist pattern.

Next, the conductor metal layer is cut, and acetone or the like is introduced from the cut portion to dissolve the photoresist and remove the resist pattern. In this way, a space is formed between the conductor metal layer and the substrate. Then, a resist pattern is formed on the portion corresponding to the power feeding body, and the exposed portion of the conductor metal layer is subjected to non-conducting treatment to form a non-conductor between the power feeding bodies, and heat is generated on the non-conductor. Form a resistor.

[0017]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a perspective view of a main part of a thermal head showing a first embodiment of the present invention, and FIG. 3 is a first view of the present invention.
FIG. 3 is a cross-sectional view of a main part of a thermal head showing the embodiment of FIG. In the figure, 23a and 23b are a plurality of sets of power feeding members, which are formed on a substrate (not shown) made of an insulating material such as alumina. The power feeding bodies 23a and 23b of each set are the power feeding bodies 2
They are insulated from each other by a plurality of strip-shaped nonconductors 24a formed integrally with 3a and 23b. One of the power supply members 23a and 23b of each set constitutes a lead electrode and is connected to a terminal of a driver IC (not shown), respectively, and the other constitutes a common electrode and is connected to each other and connected to a power source (not shown).

Further, 24b is the above-mentioned power feeding bodies 23a, 23b.
Is a non-conductor that is integrally formed with and that insulates between the power feeding bodies 23a and 23b. The non-conductor 24b and the feeder 23a,
A semi-cylindrical portion 25 is formed by a part of 23b.
The non-conductor 24b is linearly formed along the apex of the semi-cylindrical portion 25. A semi-cylindrical space 26 is formed on the substrate side of the semi-cylindrical portion 25, and a strip-shaped plate 27 made of highly insulating polyimide is closed at the opening of the space 26. On the other hand, the semi-cylindrical portion 25
A heat generating resistor 29 is formed on the non-conductor 24b to electrically connect the power feeding bodies 23a and 23b. Therefore, the heating resistor 29 has a shape along the semi-cylindrical portion 25, and has a width that partially overlaps the end portions of the power feeding members 23a and 23b.

As described above, one of the feeders 23a and 23b constitutes a lead electrode and the other constitutes a common electrode. Then, the heating resistor 29 located between the two
When a voltage corresponding to print data is selectively applied to the heating resistor 29, the heating resistor 29 generates heat to print one dot. The heating resistor 29 is formed so as to correspond to each set of the power feeders 23a and 23b.

The reference numeral 31 designates the power feeding members 23a and 23b,
The protective layer covers the non-conductor 24 a and the heating resistor 29. In this way, a line type thermal head can be formed by arranging a plurality of the heating resistors 29 in the line direction. In the thermal head having the above structure, since the space 26 is formed under the non-conductor 24b, the heat generated by the heat generating resistor 29 is not dissipated to other parts, the heat generating efficiency is improved, and printing is performed. The quality can be improved. Moreover, since the heat insulating layer 12 (see FIG. 2) formed of glaze glass or the like is not provided, the maximum temperature of the heating resistor 29 when printing is performed by the thermal head can be increased.

By the way, the feeder pattern composed of the feeders 23a and 23b and the non-conductors 24a and 24b is formed by anodizing the aluminum layer on the substrate, and the aluminum layer is anodized. The parts that have not been applied become the power feeders 23a and 23b,
The portions subjected to the anodizing process become the nonconductors 24a and 24b.

The space 26 is formed by tunneling a part of the aluminum layer.
FIG. 4 is a process diagram showing a method of manufacturing a thermal head showing a first embodiment of the present invention, FIG. 5 is a diagram showing a laser cut portion in the first embodiment of the present invention, and FIG. 6 is a heating resistor formed. FIG. 7 is an explanatory diagram of the aluminum layer before the heating, and FIG. 7 is an explanatory diagram of the aluminum layer after the heating resistor is formed. 4A is a process drawing of forming a polyimide resist pattern, FIG. 4B is a process drawing of forming an aluminum layer, and FIG.
Is a process drawing for removing the photoresist portion, (d) is a process drawing for forming a resist pattern, (e) is a process drawing for peeling (peeling) the photoresist, (f) is a process drawing for forming the heating resistor 29, 6A and 6A are cross-sectional views of the aluminum layer, and FIG. 6B is a perspective view of the aluminum layer.

First, a substrate 35 made of an insulating material such as alumina is rotated at a rotation speed of 2000 [rpm], and polyimide is spin-coated on the substrate 35 to form a polyimide layer. A photoresist is spin-coated on the top to form a resist layer. In this case, the polyimide layer has a thickness of 1 [μm] and the resist layer has a thickness of 3
[Μm].

Next, the photoresist is exposed by using a glass mask or the like, and then developed.
And, a polyimide resist pattern 38 consisting of a photoresist portion 37 on the polyimide portion 36 is formed.
The polyimide resist pattern 38 is baked at 150 [° C.] to cure the photoresist. As a result, the photoresist portion 37 of the polyimide resist pattern 38 is baked, as shown in FIG. The cross section is semicircular. In this case, the pattern width of the polyimide resist pattern 38 is 0.3.
[Mm].

Subsequently, a conductor metal layer for forming the power feeding bodies 23a and 23b and the nonconductors 24a and 24b is formed. In this case, aluminum is used as the conductor metal, and the thickness is 1 by vapor deposition as shown in FIG.
An aluminum layer 39 of [μm] is formed. for that reason,
A vacuum deposition apparatus (not shown) is used to set control conditions.

In this case, the aluminum layer 39 and the substrate 35
The vapor deposition temperature is set to 150 ° C. in consideration of the adhesion strength between the aluminum layer 39 and the polyimide resist pattern 38, and wire bonding when mounting the driver IC. Thus, after forming the aluminum layer 39, the polyimide resist pattern 38 and the substrate 35 on which the aluminum layer 39 is formed
5, both ends or, for example, a portion dividing the plurality of heating resistors 29 into each block is cut by a laser (not shown) or the like as shown in FIG. In FIG. 5, 4
Reference numeral 1 is a laser cut portion formed at a predetermined position of the semi-cylindrical portion 39a of the aluminum layer 39.

Next, acetone is introduced from the laser cut portion 41 between the aluminum layer 39 and the substrate 35,
The photoresist portion 37 is removed. Therefore, the substrate 35 on which the polyimide resist pattern 38 and the aluminum layer 39 are formed is immersed in an acetone bath (not shown), ultrasonic waves are applied for 3 minutes, and this is repeated three times. As a result, when acetone enters between the aluminum layer 39 and the substrate 35 from the laser cut portion 41 to dissolve the photoresist and remove the photoresist portion 37, as shown in FIG. While the space 26 is formed, the polyimide portion 36 serves as a strip-shaped plate 27 that closes the opening of the space 26.

Then, as shown in FIG. 4 (d), a thin film process including a photolithography process, a dry etching process, etc. is used to form a portion having a thickness of 3 [μm] corresponding to the power supply members 23a and 23b. A resist pattern 43 is formed.
In this case, a photoresist is applied on the aluminum layer 39, the photoresist is exposed using a glass mask or the like, and developed to form a resist pattern 43. Next, the exposed portion of the aluminum layer 39 is subjected to a non-conductor treatment.

The non-conducting treatment is performed by the aluminum layer 3 described above.
9 is anodized. in this case,
Aluminum layer 39 on which resist pattern 43 is formed
And the substrate 35 is dipped in a 3% oxalic acid solution,
A direct current of [V] and an alternating current of 80 [V] were superposed and the current density was set to 100 [A / m ² ], and this was applied as a melting voltage for 4 minutes. In this way, the aluminum layer 3
Nonconductors 24a and 24b are formed on the substrate 9.

Next, as shown in FIG. 4 (e), the photoresist is peeled off and the resist pattern 43 is removed. As shown in FIG. 6, the power supply members 23a and 23b and the nonconductors 24a and 24b are formed. A power feeding pattern is formed. Then, for example, TaSiO ₂ is coated on the non-conductor 24b by using the thin film process.
A heating resistor 29 is formed as shown in FIG. In this case, the heating resistor 29 is made of a layer having a thickness of 2000 [Å], and has a width that partially overlaps the end portions of the power feeding members 23a and 23b. In addition, the heating resistor 29 is provided in each of the feeders 23a and 23b.
Is formed by the number corresponding to each set.

Finally, as shown in FIG. 4 (f), the power feeding members 23a and 23b, the non-conductor 24a and the heating resistor 29.
A protective layer 31 is formed by coating silicon oxide or the like by sputtering. Next, a second embodiment of the present invention will be described. FIG. 8 is an explanatory view of an aluminum layer after forming a heating resistor in the second embodiment of the present invention,
FIG. 9 is a conceptual diagram of a feeder pattern in the second embodiment of the present invention. 8A is a sectional view of the aluminum layer, and FIG. 8B is a perspective view of the aluminum layer.

In the figure, 26 is a space, 27 is a plate formed of polyimide, 35 is a substrate, 45 is an aluminum layer, and 46a and 46b are power supply members in which one constitutes a lead electrode and the other constitutes a common electrode, 47 is a non-conductor formed on a portion of the aluminum layer 45 other than the power feeding bodies 46a and 46b, and 49 is the aluminum layer 39.
Is a strip-shaped heating resistor formed along the apex of the semi-cylindrical portion 50 and having a thickness of 2000 [Å].

In this case, the feeding body pattern formed by the feeding bodies 46a and 46b and the non-conductor 47 extends alternately in the semi-cylindrical portion 50 so that a plurality of sets of feeding bodies 46a and 46b fold fingers. Therefore, the heating resistor 4
It suffices that only one 9 be formed, and the feeders 46a, 46b
It is not necessary to form a plurality of sets corresponding to each set. Next, a third embodiment of the present invention will be described.

FIG. 10 is a sectional view of the main part of a thermal head showing the third embodiment of the present invention. In the figure, 35 is a substrate, and 51 is a heat insulating layer formed in a band shape on the substrate 35 and having a semicircular cross section. The heat retaining layer 51 is formed of glaze glass or the like. Then, on the heat retaining layer 51, power supply bodies 53a and 53b, one of which constitutes a lead electrode and the other of which constitutes a common electrode, are formed. Similarly, a non-conductor 54 is formed between the power feeding bodies 53a and 53b above the heat retaining layer 12 to insulate the power feeding bodies 53a and 53b from each other, and an integral layer is formed by the power feeding bodies 53a and 53b and the non-conductor 54. Is forming.

A heating resistor 59 is formed on the non-conductor 54. Further, the power feeding bodies 53a and 53b and the non-conductor 54 form a band-shaped space 61 having a semicylindrical cross section at a position corresponding to the apex portion of the heat retaining layer 51. The inner diameter of the space 61 is approximately equal to the width of the heating resistor 59.
[Μm] Then, the power feeding bodies 53a, 53
The protective layer 62 is formed on the b and the heating resistor 59.

In this way, the protective layer 62 is raised by the amount of the space 61 formed, and therefore, even when printing is performed by thermal transfer using rough paper having a low surface smoothness, good paper contact is achieved. It is possible to improve the printing quality. In each of the above-mentioned embodiments, air is present in the spaces 26 (Fig. 1) and 61 (Fig. 10). By evacuating the spaces 26 and 61, it is possible to prevent heat from escaping further, and heat generation efficiency is improved. In this case, after the laser cut portion 41 (FIG. 5) is formed by a laser (not shown) and the photoresist portion 37 (FIG. 4) is removed, the laser cut portion 41 may be welded again by a laser in a vacuum chamber (not shown).

In the first and second embodiments, the plate 27 is provided at the opening of the space 26.
Instead of the plate 27, another heat retaining member may be formed. It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made based on the spirit of the present invention, and they are not excluded from the scope of the present invention.

[0038]

As described in detail above, according to the present invention, in the thermal head, a plurality of sets of power supply members are formed on the substrate, one of the sets constitutes a lead electrode, and the other forms a common electrode. Constitute. Further, a non-conductor is integrally formed between the power feeding bodies of each set to insulate the power feeding bodies from each other. Then, a heating resistor is formed between each pair of power feeding bodies on the non-conductor, and heat is generated when a voltage is applied.

In this case, since the space is formed between the non-conductor and the substrate, the heat generated by the heating resistor is not dissipated to other parts, the heat generation efficiency is improved, and the printing quality is improved. Can be made. Moreover, since the heat insulating layer is not provided, the maximum temperature of the heat generating resistor can be increased when printing is performed by the thermal head. In another thermal head of the present invention, a heat retaining layer is formed on the substrate, and a plurality of sets of power supply members are formed on the substrate and the heat retaining layer. Then, a non-conductor is integrally formed on each heat-insulating layer between the power-supplying bodies of each set to insulate the power-supplying bodies from each other, and a heating resistor is formed on the non-conductor.

In this case, since the space is formed between the non-conductor and the heat retaining layer, the heat generated by the heating resistor is not dissipated to other portions through the heat retaining layer, and the heat generating efficiency is improved. However, the printing quality can be improved. Further, since the raised portion is formed by the space, even if printing is performed by thermal transfer using rough paper having a low surface smoothness, the paper contact is improved and the printing quality can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a thermal head showing a first embodiment of the present invention.

FIG. 2 is a schematic view showing the structure of a conventional thermal head.

FIG. 3 is a cross-sectional view of essential parts of a thermal head showing a first embodiment of the present invention.

FIG. 4 is a process drawing showing the manufacturing method of the thermal head showing the first embodiment of the present invention.

FIG. 5 is a diagram showing a laser cut portion in the first embodiment of the present invention.

FIG. 6 is an explanatory diagram of an aluminum layer before forming a heating resistor.

FIG. 7 is an explanatory diagram of an aluminum layer after forming a heating resistor.

FIG. 8 is an explanatory diagram of an aluminum layer after forming a heating resistor according to a second embodiment of the present invention.

FIG. 9 is a conceptual diagram of a feeder pattern in the second embodiment of the present invention.

FIG. 10 is a cross-sectional view of essential parts of a thermal head showing a third embodiment of the present invention.

[Explanation of reference numerals] 23a, 23b, 46a, 46b, 53a, 53b
Feeder 24a, 24b, 47, 54 Non-conductor 26, 61 Space 29, 49, 59 Heating resistor 35 Substrate 38 Polyimide resist pattern 43 Resist pattern 51 Heat insulation layer

Claims (3)

[Claims] 1. (a) a substrate; (b) a plurality of sets formed on the substrate, one of each set forming a lead electrode and the other forming a common electrode; and (c) each set. A non-conductor that is integrally formed between a pair of power feeding bodies and insulates between the power feeding bodies,
(D) a heating resistor that is formed between the respective sets of power supply members on the non-conductor and that generates heat when a voltage is applied,
(E) A thermal head having a space formed between the nonconductor and the substrate. 2. (a) a substrate; (b) a heat retaining layer formed on the substrate; and (c) a plurality of sets formed on the substrate and the heat retaining layer, one of each set constituting a lead electrode. And (e) a non-conductor that is integrally formed between the power feeding bodies of the respective groups on the heat insulating layer and that insulates the power feeding bodies from each other. It has a heating resistor that is formed between each pair of power supply members on the conductor and generates heat when a voltage is applied, and (f) a space is formed between the nonconductor and the heat retaining layer. And thermal head. 3. A resist pattern is formed on (a) a substrate, (b) a conductor metal layer is formed on the substrate and the resist pattern, (c) the conductor metal layer is cut, and the resist pattern is formed. Is removed to form a space between the conductor metal layer and the substrate, (d) a resist pattern is formed in a portion corresponding to the power feeding body, and (e) the conductor metal layer is made non-conducting with respect to the exposed portion. A method of manufacturing a thermal head, characterized in that a heat treatment is performed to form a non-conductor between the power feeding bodies, and (f) a heating resistor is formed on the non-conductor.