JP2015123604A - Thermal head, manufacturing method of the same, and thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable thermal head which realizes improvement of the printing efficiency and printing quality while achieving improvement of the producibility and low costs, and to provide a manufacturing method of the thermal head, and a thermal printer.SOLUTION: A thermal head includes: a base part 23 which is formed by sintering sinterable powder and has a recessed part 23a; a lid part 24 which closes the recessed part 23a and forms a cavity part 21 between itself and the base part 23; and multiple heating elements 31 which are arranged in a portion of the lid part 24, which is located above the cavity part 21, so as to be spaced away from each other. The cavity part 21 is filled with a granular filler 25.

Description

  The present invention relates to a thermal head, a method for manufacturing a thermal head, and a thermal printer.

  2. Description of the Related Art Conventionally, thermal printers that print on special recording paper (thermal paper) that develops color when heat is applied are known as printers for printing various labels, receipts, tickets, and the like. Thermal printers are widely used because they can be reduced in size and weight, and have a simple configuration that does not use toner or ink.

  In a thermal printer, a recording sheet is sandwiched between a platen roller and a thermal head, and the printing surface (thermal recording surface) of the recording sheet is heated by a heating element of the thermal head while feeding the recording sheet by rotating the platen roller. Thus, printing is performed by coloring the printing surface. The thermal head has a configuration in which a heat storage layer made of glass or the like is laminated on a substrate, and a plurality of heating elements are arranged on the heat storage layer.

Here, a configuration is known in which a hollow portion is provided between the substrate and the heat storage layer, and heating elements are arranged in a portion of the heat storage layer located on the hollow portion.
According to this configuration, since the cavity can function as a heat insulating layer, it is possible to efficiently transmit the heat energy generated in the heat generating element to the recording paper side by suppressing the heat radiation to the substrate side. It is considered that the printing efficiency (energy efficiency) can be improved.

By the way, in order to suppress heat radiation from the heating element to the substrate side, it is preferable to reduce the distance between the heating element and the cavity, that is, to make the heat storage layer thin.
However, if the heat storage layer is made thin, the strength of the heat storage layer may decrease and the heat storage layer may be damaged. That is, since a load is applied to the heating element by the pressing force of the platen roller, the heat storage layer is bent and deformed into the cavity together with the heating element and the protective film covering the heating element. And if the tensile stress by bending becomes more than the destructive stress of a thermal storage layer, a thermal storage layer will be damaged.
Further, if the heat storage layer is greatly bent and deformed, the contact state between the recording paper and the heating element (and the protective film) is deteriorated, and a desired contact pressure cannot be secured between the recording paper and the heating element, and the recording paper is heated. There is a risk that it will be difficult to transmit energy.

  Therefore, for example, in Patent Document 1 below, when the heating element is pressed, a bending limiting portion that contacts the heat storage layer and limits the bending of the heat storage layer is provided inside the hollow portion to suppress damage to the heat storage layer. A configuration is disclosed.

JP 2010-89279 A

However, in the configuration of Patent Document 1 described above, since a gap is provided between the heat storage layer and the deflection limiting portion, the gap is bent in the heat storage layer. In this case, although damage to the heat storage layer can be prevented, there is still room for improvement in terms of securing the contact pressure.
Also, in the heat storage layer, the amount of bending of the heat storage layer is different between the portion supported by the bending restriction portion and the portion not supported by the bending restriction portion, so the contact state with the recording paper is different between each heating element, There is a problem that uneven printing occurs.

Furthermore, when providing a concave portion and a deflection limiting portion on the substrate, after forming the concave portion on the substrate in a state of leaving the protruding portion that becomes the deflection limiting portion, the tip of the protruding portion is processed by polishing or etching, It is necessary to make the tip of the protruding portion lower than the substrate surface. Thus, since it is necessary to post-process with respect to a board | substrate, it leads to the fall of manufacturing efficiency and the increase in manufacturing cost. In particular, when a plurality of deflection limiting portions are provided in the recess, it is difficult to process all the deflection limiting portions to a uniform height, and it is difficult to improve printing unevenness. In addition, the protrusion may be damaged during processing.
Moreover, since it is necessary to stick a heat storage layer with respect to a board | substrate after forming a recessed part and a bending | flexion restriction | limiting part, this also becomes a factor of the fall of manufacturing efficiency and the increase of manufacturing cost.

  The present invention has been made in view of such circumstances, and has improved the printing efficiency and the printing quality by improving the manufacturing efficiency and reducing the cost, and is a highly reliable thermal head. Another object of the present invention is to provide a thermal head manufacturing method and a thermal printer.

(1) In the thermal head according to the present invention, the first powder is bonded by sintering or adhesion, and the first bonded body having a recess and the second powder are bonded by sintering or bonding, A second combination that closes the recess and forms a cavity with the first combination, and a portion of the second combination that is located on the cavity is arranged with a gap. A plurality of heat generating elements, and the hollow portion is filled with a granular filler.

  According to this configuration, since the heating elements are arranged in the portion of the second combined body located on the cavity, the cavity can function as a heat insulating layer. Therefore, it is possible to suppress the heat energy generated in the heating element from being radiated from the second combined body toward the first combined body. Therefore, since heat energy can be efficiently transmitted to the recording paper, printing efficiency can be improved.

Here, in the configuration of the present invention, since the filler is filled in the cavity, the second combined body is supported from the first combined body side by the filler. Therefore, even when the pressing force of the platen roller acts on the second combined body via the heat generating element of the thermal head, it is possible to suppress the bending deformation of the second combined body. Thereby, the breakage of the second combined body can be suppressed, and a desired contact pressure can be ensured between the recording paper and the heating element, and the thermal energy can be efficiently transmitted to the recording paper. In addition, since the cavity is filled with the filler, the contact state between the heating elements and the recording paper can be kept uniform, and the printing quality can be improved by suppressing the occurrence of printing unevenness. .
In addition, by supporting the second combined body with the filler, it is possible to reduce the thickness of the second combined body, and the distance between the heating element and the cavity can be made closer. The printing efficiency can be further increased.

In addition, since a filler will carry out point contact with the inner surface of a cavity part, the contact area between a 2nd conjugate | bonded_body and a filler can be reduced, and the thermal energy radiated | emitted via a filler can be suppressed.
Further, since the fillers are in point contact with each other in the hollow portion, the contact area between the fillers can be reduced, and the heat energy radiated through the filler can be suppressed.
Furthermore, in the hollow portion, the gas filled between the fillers performs a heat insulating function, so that the printing efficiency can be improved as compared with the configuration in which the hollow portion is not provided.

(2) In the thermal head according to the present invention, the first powder and the second powder may be made of the same material, and the first combined body and the second combined body may be integrally formed. .
According to this configuration, the first combined body and the second combined body are integrally formed of the same material, so that the manufacturing efficiency can be further improved and the cost can be reduced.

(3) In the thermal head according to the present invention, the filler may be made of the same material as the particles of the first powder.
According to this configuration, since the filler is formed of the same material as the particles constituting the first combined body, further improvement in manufacturing efficiency and cost reduction can be achieved.

(4) In the thermal head according to the present invention, the filler may be made of a material having a lower thermal conductivity than the particles of the first powder.
According to this configuration, the thermal energy radiated through the filler can be suppressed, so that the printing efficiency can be further improved.

(5) In the thermal head according to the present invention, the filler may be made of a material having a larger particle diameter than the particles of the first powder.
According to this configuration, the number of fillers filled in the recesses can be reduced, so that the number of contact points between the fillers can be reduced. Therefore, since the heat energy radiating path is reduced and the heat energy radiated through the filler can be suppressed, the printing efficiency can be further improved.
Furthermore, since the clearance gap between fillers can also be ensured, the heat insulation effect by gas can be exhibited more effectively.

(6) In the thermal head according to the present invention, the cavity may be filled with a gas having a lower thermal conductivity than air.
According to this configuration, it is possible to further increase the heat insulating effect as compared with the case where air is filled between the fillers, and it is possible to further improve the printing efficiency.

(7) In the thermal head according to the present invention, the inside of the hollow portion may be held in a reduced pressure atmosphere.
According to this configuration, it is possible to further increase the heat insulating effect as compared with the case where gas is filled between the fillers, and it is possible to further improve the printing efficiency. In addition, since the 2nd conjugate | bonded_body is supported by the filler, even if it is a case where the inside of a cavity part is hold | maintained in a pressure-reduced atmosphere, it can suppress that a 2nd conjugate | bonded body is bent toward a cavity part by a negative pressure. .

(8) The thermal head manufacturing method according to the present invention is the thermal head manufacturing method according to the present invention, wherein the first bonding layer is formed by selectively bonding the first powder by sintering or adhesion. A first bonded body forming step of forming a first bonded body by stacking a plurality of layers, and a second bonded layer formed by selectively bonding the second powder by sintering or adhesion on the first bonded body A second combined body forming step of forming the second combined body by stacking, wherein in the first combined body forming step, the first powder other than the portion located in the recess. The concave portion is formed by combining the first powder.
According to this configuration, since the first combined body and the second combined body are formed by laminating the bonding layers in which the first powder and the second powder are selectively bonded, the first bonding The cavity can be formed simultaneously with the process of forming the body and the second combined body. That is, there is no need for post-processing such as a conventional step of forming a recess (or a deflection limiting portion) on the substrate, a step of bonding the substrate and the heat storage layer, etc., so that it is possible to improve manufacturing efficiency and reduce costs. .
Furthermore, by changing the shape of the bonding layer (by changing the portion to be bonded), the size of the substrate and the cavity, the position in plan view of the cavity, etc. can be arbitrarily and easily changed, The degree of freedom in design can be improved. In this case, for example, it is possible to simultaneously form a plurality of substrates having different designs such as the size and the position of the cavity on the same modeling tray. For this reason, it is not necessary to change or adjust the equipment according to the size, the position of the cavity, etc. as in the prior art, and the thermal head can be manufactured at a lower cost.

(9) In the method for manufacturing a thermal head according to the present invention, the first powder filled in the recess is removed between the first combined body forming step and the second combined body forming step, You may have the filling process filled with a filler.
According to this configuration, after removing the powder in the recess, it is only necessary to fill the recess with any particles as a filler, so that it is possible to improve the degree of freedom of material selection while suppressing a decrease in manufacturing efficiency. Can do.

(10) A thermal printer according to the present invention includes the thermal head according to the present invention.
According to this configuration, since the thermal head of the present invention is provided, it is possible to improve the printing efficiency and the printing quality and provide a highly reliable thermal printer.

  According to the present invention, it is possible to provide a thermal head and a thermal printer with high reliability by improving the printing efficiency and the printing quality while improving the manufacturing efficiency and reducing the cost.

1 is a schematic configuration diagram of a printer. It is a schematic plan view of a thermal head. FIG. 3 is a cross-sectional view corresponding to the line AA in FIG. 2. FIG. 3 is a cross-sectional view corresponding to the line BB in FIG. 2. It is process drawing for demonstrating a base part formation process. It is process drawing for demonstrating a lid part formation process. It is a schematic plan view of a modeling tray. It is process drawing for demonstrating the manufacturing process of the board | substrate in 2nd Embodiment.

Next, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
[Thermal printer]
First, a thermal printer 10 (hereinafter simply referred to as a printer 10) provided with the thermal head 13 of the present invention will be described. FIG. 1 is a schematic configuration diagram of the printer 10.
As shown in FIG. 1, the printer 10 of this embodiment performs printing on a recording paper P (thermal paper) that changes color when heat is applied, and is suitable for printing various labels, receipts, tickets, and the like. Used for. The recording paper P is set in a roll paper storage unit (not shown) in a state of roll paper (not shown) wound in a roll shape, and printing is performed on a portion pulled out from the roll paper.

  Specifically, the printer 10 includes a main body frame 11, a platen roller 12 rotatably supported by the main body frame 11, a thermal head 13 arranged to face the outer peripheral surface of the platen roller 12, the platen roller 12, and the thermal head. 13 is provided with a paper feed mechanism 14 that feeds the recording paper between and a pressure mechanism 15 that presses the thermal head 13 toward the platen roller 12.

(Thermal head)
2 is a schematic plan view of the thermal head 13, and FIG. 3 is a cross-sectional view taken along the line AA of FIG. 4 is a cross-sectional view taken along line BB in FIG.
As shown in FIGS. 2 to 4, the thermal head 13 of this embodiment includes a substrate 22 having a hollow portion 21 therein. The substrate 22 has a rectangular shape in plan view, and has a long side portion extending along the width direction (main scanning direction X) of the recording paper P and a short side extending along the conveyance direction (sub-scanning direction Y) of the recording paper P. And a portion. In the following description, in the thermal head 13, the extending direction of the long side portion of the substrate 22 is simply referred to as the main scanning direction X, and the extending direction of the short side portion is referred to as the sub-scanning direction Y.

  The substrate 22 is formed by sintering a sinterable powder (first powder and second powder) such as alumina ceramics or zirconia ceramics, and a base part (first combined body) 23 having a recess 23a; A lid portion (second combined body) 24 that closes the concave portion 23 a and forms the cavity portion 21 with the base portion 23 is integrally formed. The material for forming the substrate 22 can be appropriately selected as long as it can be sintered. However, it is preferable to select a material having a relatively low thermal conductivity, such as an insulator.

  As shown in FIG. 2, the cavity 21 described above extends along the main scanning direction X at the center in the sub-scanning direction Y within the substrate 22. Further, as shown in FIG. 3, the cavity 21 is disposed closer to the surface 22 a in the thickness direction of the substrate 22. In this case, the depth D (the thickness of the lid portion 24) from the surface 22a of the substrate 22 to the cavity portion 21 is set to about 0.2 μm to 100 μm. Since the depth D is set to 0.2 μm or more, the concave portion 23 a can be reliably closed by the lid portion 24. On the other hand, since the depth D is set to 100 μm or less, it is possible to effectively suppress the heat radiation of the heat energy generated in the heating element 31 described later.

  Here, the hollow filler 21 is filled with a granular filler 25. In the present embodiment, the filler 25 is made of the same material as the powder particles constituting the substrate 22 described above, and is spread in the cavity 21. In this case, in the cavity portion 21, the fillers 25 are laid in a state of being in point contact with each other so as to be inoperable as in a close-packed structure (cubic close-packed structure or hexagonal close-packed structure). Is preferred. Therefore, among the fillers 25, the fillers 25 located at the outermost peripheral part are in contact with the inner surface of the cavity 21. In the case where the close-packed structure is adopted, the space filling rate of the filler 25 in the cavity 21 is 74%. Further, in the hollow portion 21, the gaps between the fillers 25 are filled with gas (for example, air).

As shown in FIG. 2, on the surface 22 a of the substrate 22, a plurality of heating elements 31, individual electrodes 32 individually connected to each heating element 31, and a common electrode 33 electrically connected to all the heating elements 31. And are formed.
The heating elements 31 are arranged at intervals in the main scanning direction X at a portion of the surface 22 a of the substrate 22 located on the cavity 21.

The common electrode 33 includes a main wiring 33a and a plurality of connection wirings 33b that connect the main wiring 33a and each of the heat generating elements 31 separately. The main wiring 33 a extends along the main scanning direction X on the surface 22 a of the substrate 22 on the one side in the sub-scanning direction Y with respect to the heating element 31.
As shown in FIGS. 2 and 4, each connection wiring 33 b extends along the sub-scanning direction Y and is arranged at intervals along the main scanning direction X. Each connection wiring 33 b is integrally formed with the main wiring 33 a at one end in the sub-scanning direction Y, and is connected to the corresponding heating element 31 at the other end in the sub-scanning direction Y.

  The individual electrodes 32 are arranged on the surface 22 a of the substrate 22 on the other side in the sub-scanning direction Y with respect to the heat generating element 31 with an interval along the main scanning direction X. Each individual electrode 32 has one end in the sub-scanning direction Y connected to the corresponding heating element 31 and the other end in the sub-scanning direction Y connected to a driver IC (not shown). The driver IC has a plurality of switching elements, and controls the energization state of each heating element 31 by selectively turning on / off these switching elements. Further, a protective film 35 (see FIG. 4) is formed on the surface 22a of the substrate 22 to cover the heat generating element 31, the individual electrodes 32, and the common electrode 33 together.

[Method of manufacturing thermal head]
Next, a method for manufacturing the above-described thermal head 13 will be described. FIG. 5 is a process diagram for explaining the base portion forming process. In the following description, the manufacturing process of the substrate 22 in the thermal head 13 described above will be mainly described.
The manufacturing process of the substrate 22 in the present embodiment includes a base portion forming step for forming the base portion 23 and a lid portion forming step for forming the lid portion 24 of the substrate 22.

  As shown in FIG. 5A, in the base portion forming step, the powder layer 51 in which the powder is supplied in layers is selectively sintered based on the cross-sectional data of the base portion 23 (see FIG. 3). Thus, a bonding layer forming step for forming the bonding layer 52 (see FIG. 5B) is included. Then, by repeating this bonding layer forming step and sequentially stacking the bonding layers 52, the above-described base portion 23 is formed. Note that the bonding layer forming step of this embodiment is performed in the atmosphere.

Specifically, first, the first layer of powder is supplied onto the modeling tray 50, and then the powder is leveled to form the powder layer 51. Next, as shown in FIG. 5B, the laser 55 is scanned on the powder layer 51, and the laser 55 is selectively irradiated to a portion of the powder layer 51 to be sintered. Then, a portion of the powder layer 51 irradiated with the laser 55 is heated and sintered to form the first bonding layer 52. The laser used in the bonding layer forming step can be appropriately selected as long as it can sinter powder, and for example, a CO ₂ laser, a YAG laser, a green laser, a UV laser, or the like can be used. .

  Next, as shown in FIG. 5C, the second powder is supplied onto the first powder layer 51 on which the bonding layer 52 is formed, and then the powder is flattened to 2 A first powder layer 51 is formed. Thereafter, as shown in FIG. 5D, similarly to the first layer, the sintered portion of the powder layer 51 is irradiated with a laser 55 so that the second bonding layer 52 becomes the first layer. Is laminated on the bonding layer 52. And the coupling layer 52 is laminated | stacked by repeating the process mentioned above.

  In addition, it is preferable that the particle diameter of the powder used by this embodiment is about 0.1 micrometer-200 micrometers. By using a powder having a particle size of 0.1 μm or more, the thickness of each bonding layer 52 (powder layer 51) can be ensured and the number of bonding layer forming steps can be reduced, thereby improving manufacturing efficiency. Can do. Further, by using a powder having a particle diameter of 200 μm or less, each cross-sectional data can be subdivided to reduce the thickness of each bonding layer 52 (powder layer 51), so that the substrate 22 can be formed with high definition.

Here, as shown in FIG. 5 (e), in each of the bonding layer forming steps, in the bonding layer forming step of forming the bonding layer 52 including the recess 23a, a portion corresponding to the base portion 23 in the powder layer 51 is formed. Among these, the laser 55 is selectively irradiated to a portion other than the portion where the concave portion 23a is formed. As a result, in the portion corresponding to the base portion 23 in the powder layer 51, the portion of the powder layer 51 that forms the recess 23a remains as the powder 56, and the portion of the powder layer other than the portion that forms the recess 23a. A tie layer 52 formed by sintering 51 is formed. That is, the bonding layer 52 is formed so as to surround the periphery of the powder 56.
Thereby, the base part 23 filled with the powder in the recessed part 23a is formed.

FIG. 6 is a process diagram for explaining the lid portion forming process.
As shown in FIG. 6A, in the lid portion forming step, the bonding layer 52 is formed by the same method as the base portion forming step described above by performing the bonding layer forming step based on the cross-sectional data of the lid portion 24. I will do it. Specifically, first, the powder layer 51 is formed on the base portion 23. Thereafter, as shown in FIG. 6B, similarly to the above-described bonding layer forming step, the portion of the powder layer 51 to be sintered is selectively irradiated with a laser 55, so that the lid portion 24 A bonding layer 52 is stacked on the base portion 23.

  Here, in the lid portion forming step, the portion of the powder layer 51 located in the plan view shape of the substrate 22 is sintered, whereby the concave portion 23a of the base portion 23 is closed. As a result, the cavity portion 21 is formed between the base portion 23 and the lid portion 24, and the powder 56 is filled in the cavity portion 21. That is, the hollow portion 21 is filled with the filler 25 composed of the powder 56 constituting the base portion 23. Further, in the cavity 21, the gaps between the fillers 25 are filled with air.

  Thereafter, the bonding layer forming step is performed one or more times until the lid portion 24 has a desired thickness. Thereby, the lid portion 24 is integrally formed with the base portion 23, and the substrate 22 in which the filler 25 is filled in the cavity portion 21 is formed.

Finally, as shown in FIG. 6C, the powder around the substrate 22 is removed, and the substrate 22 is taken out from the modeling tray 50.
Thus, the manufacturing process of the substrate 22 is completed.

  Thereafter, the heating element 31, the individual electrode 32, the common electrode 33, the protective film 35, and the like are sequentially formed on the surface 22 a of the substrate 22, and the driver IC is mounted on the substrate 22. Complete.

[How the printer works]
Next, an operation method of the printer 10 described above will be described.
When print information is input through an input operation unit (not shown), the paper feed mechanism 14 described above is driven based on this print information, and the platen roller 12 rotates. Then, as shown in FIG. 4, the recording paper P is sent downstream in the sub-scanning direction Y while being sandwiched between the outer peripheral surface of the platen roller 12 and the thermal head 13.

  On the other hand, in the thermal head 13, the switching element of the driver IC is turned on / off based on the print information, so that the heating element 31 corresponding to the switching element in the on state among the heating elements 31 has a current. Flows selectively. Thereby, the heating element 31 in the on state generates heat. When the recording paper P passes through the thermal head 13, the recording paper P is heated by the heating element 31 that is in an on state, so that the portion is colored. As a result, various characters and figures can be clearly printed on the sent recording paper P.

  As described above, in the thermal head 13 of the present embodiment, since the heating elements 31 are arranged in the portion of the surface 22a of the substrate 22 located on the cavity 21, the cavity 21 can function as a heat insulating layer. . Therefore, it is possible to suppress the heat energy generated in the heating element 31 from being radiated from the lid portion 24 toward the base portion 23. As a result, since heat energy can be efficiently transmitted to the recording paper P, printing efficiency can be improved.

In this embodiment, since the filler 25 is filled in the cavity portion 21, the lid portion 24 is supported by the filler 25 from the base portion 23 side. Therefore, even when the pressing force of the platen roller 12 acts on the lid portion 24 via the heat generating element 31 (protective film 35) of the thermal head 13, the bending deformation of the lid portion 24 can be suppressed. Thereby, the breakage of the lid portion 24 can be suppressed, and a desired contact pressure can be ensured between the recording paper P and the heating element 31, and the heat energy can be efficiently transmitted to the recording paper P. In addition, since the cavity portion 21 is filled with the filler 25, the contact state between the heating elements 31 and the recording paper P can be kept uniform, and the occurrence of printing unevenness can be suppressed and the printing quality can be improved. Can be improved.
In addition, by supporting the lid portion 24 with the filler 25, the lid portion 24 can be thinned, and the distance between the heating element 31 and the cavity portion 21 can be made closer. The printing efficiency can be further improved and the printing efficiency can be further improved.

Since the filler 25 makes point contact with the inner surface of the cavity portion 21, the contact area between the lid portion 24 and the filler 25 is reduced, and the heat energy radiated through the filler 25 is reduced. Can be suppressed.
Further, since the fillers 25 are in point contact with each other in the hollow portion 21, the contact area between the fillers 25 can be reduced, and the thermal energy radiated through the filler 25 can be suppressed.
Furthermore, in the cavity portion 21, the air filled between the fillers 25 performs a heat insulating function, so that the printing efficiency can be improved as compared with a configuration in which the cavity portion 21 is not provided.

Further, by integrally forming the base portion 23 and the lid portion 24 with the same material, it is possible to further improve the manufacturing efficiency and reduce the cost.
Furthermore, since the filler 25 is formed of the same material as the particles constituting the base portion 23, further improvement in manufacturing efficiency and cost reduction can be achieved.

  Further, since the substrate 22 of the present embodiment is formed by laminating the bonding layer 52 to which the powder is selectively bonded, the cavity 21 can be formed simultaneously with the formation process of the substrate 22. Become. That is, there is no need for post-processing such as a conventional step of forming a recess (or a deflection limiting portion) on the substrate, a step of bonding the substrate and the heat storage layer, etc., so that the manufacturing efficiency can be improved and the cost can be reduced. .

  Furthermore, by changing the shape of the bonding layer 52 (by changing the portion to be sintered), the size of the substrate 22 and the cavity 21, the position of the cavity 21 in plan view, etc. can be changed arbitrarily and easily. And the degree of freedom in design can be improved. In this case, for example, as shown in FIG. 7, it is also possible to simultaneously form a plurality of substrates 22 having different designs such as the size and the position of the cavity 21 (see FIG. 2) on the same modeling tray 50. For this reason, it is not necessary to change or adjust the equipment according to the size, the position of the cavity 21 or the like as in the prior art, and the thermal head 13 can be manufactured at a lower cost.

  Since the printer 10 of the present embodiment includes the thermal head 13 described above, it is possible to provide a highly reliable printer 10 with improved printing efficiency and printing quality.

Second Embodiment
Next, a second embodiment of the present invention will be described. This embodiment is different from the first embodiment described above in that a material different from the powder particles constituting the base portion 23 is used as the filler 62. In the following description, the same components as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

FIG. 8 is an explanatory diagram for explaining a manufacturing process of the thermal head 13 (substrate 22) of the second embodiment.
As shown in FIG. 8A, in this embodiment, the powder 56 (FIG. 8) remaining in the concave portion 23a of the base portion 23 is in the subsequent stage of the above-described base substrate forming process and before the lid substrate forming process. 5 (e)) is removed (powder removal step).

  Next, as shown in FIG. 8B, a granular filler 62 is filled into the recess 23a of the base portion 23 (filling step). The filler 62 has a lower thermal conductivity than the powder particles (alumina ceramics (thermal conductivity is 32 W / mK), zirconia ceramics (thermal conductivity is 3 W / mK), etc.) constituting the base portion 23. It is preferable to use a material. Examples of such materials include particles mainly composed of glass and silica (0.5 to 0.7 W / mK), hard resins (styrene, acrylic, polyacetal, nylon, epoxy, hard vinyl chloride, polycarbonate, melamine, etc. , PPS, PEEK, etc. (thermal conductivity 0.1-0.3 W / mK) particles, fullerene (thermal conductivity 0.4 W / mK), calcium silicate (0.05 W / mK), etc. Can do.

  Then, after the above-described filler 62 is spread in the recess 23a, as shown in FIGS. 8C and 8D, a lid portion forming step is performed by the same method as in the first embodiment. As a result, the lid portion 24 is integrally formed with the base portion 23, and the substrate 22 in which the filler 62 is filled in the cavity portion 21 is formed.

According to this configuration, in addition to the same effects as those of the first embodiment described above, the thermal energy radiated through the filler 62 can be suppressed, so that the printing efficiency can be further improved. it can.
In addition, after removing the powder 56 in the concave portion 23a, arbitrary particles are simply filled into the concave portion 23a as the filler 62, so that a reduction in manufacturing efficiency is suppressed and the degree of freedom in material selection is improved. Can do.

In addition, in 2nd Embodiment mentioned above, although the structure which uses the material with low heat conductivity with respect to the powder particle | grains which comprise the base part 23 as the filler 62 was demonstrated, not only this but the base part 23 is used. A material having the same particle diameter as that of the powder particles and having a large particle diameter may be used as the filler 62.
In this case, since the number of fillers 62 filled in the recesses 23a can be reduced, the number of contact points between the fillers 62 can be reduced. Therefore, the heat energy radiation path can be reduced and the heat energy radiated through the filler 62 can be suppressed, so that the printing efficiency can be further improved.
Furthermore, since the clearance gap between the fillers 62 can also be ensured, the heat insulation effect by air can be exhibited more effectively.

  The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

For example, in the above-described embodiment, the configuration in which the manufacturing process of the substrate 22 is performed in the atmosphere and the gap between the fillers 25 and 62 in the cavity portion 21 is filled with air has been described. A gas having a lower thermal conductivity than air (0.025 W / mK) may be filled as the filling gas. As the filling gas, it is preferable to use argon gas (0.018 W / mK), carbon dioxide gas (0.018 W / mK), or a mixed gas thereof from the viewpoints of handling, availability, price, and the like. In this case, the above-described filling gas can be filled into the cavity 21 by performing the above-described manufacturing process of the substrate 22 in the atmosphere of the filling gas.
According to this configuration, it is possible to further enhance the heat insulating effect of the cavity 21 compared to the case where air is filled between the fillers 25 and 62, and the printing efficiency can be further improved.

  Further, the manufacturing process of the substrate 22 may be performed in a reduced-pressure atmosphere, and the inside of the cavity 21 may be kept in a vacuum. And it becomes possible to raise the heat insulation effect of the cavity part 21 by hold | maintaining the inside of the cavity part 21 in a vacuum. Since the lid portion 24 is supported by the fillers 25 and 62, the lid portion 24 bends toward the inside of the cavity portion 21 due to negative pressure even when the inside of the cavity portion 21 is held in a vacuum. Can be suppressed.

  Furthermore, in the above-described embodiment, the configuration in which the bonding layer 52 is formed using the same powder in each bonding layer forming step has been described. However, the present invention is not limited to this, and the particle diameter and the material are determined according to the cross-sectional position to be formed. Different powders may be used. For example, different powders may be used for the base portion 23 and the lid portion 24.

In the above-described embodiment, the configuration in which the bonding layer 52 is formed by sintering with the laser 55 has been described. However, if the powder layer 51 is selectively bonded to form the bonding layer 52, The powders may be bonded together by adhesion. For example, the bonding layer 52 is formed by spraying an adhesive onto the powder layer 51 using an inkjet printer, a spray coater, or the like, and selectively adhering the powder layer 51. Thereafter, similarly to the above-described embodiment, the substrate 22 can be formed by sequentially laminating the bonding layer 52.
In this case, the substrate 22 can be manufactured from a material that cannot be sintered by the laser 55 (alumina, zirconia, aluminum nitride, silicon nitride, silicon carbide, gypsum, vitreous, hard resin). Can be improved.

  In addition, in the range which does not deviate from the meaning of this invention, it is possible to replace suitably the component in the embodiment mentioned above by a known component, and you may combine each modification mentioned above suitably.

DESCRIPTION OF SYMBOLS 10 ... Thermal printer 13 ... Thermal head 21 ... Hollow part 22 ... Board | substrate 23 ... Base part (1st coupling body)
23a ... concave 24 ... lid part (second combined body)
25, 62 ... filler 31 ... heating element 52 ... bonding layer

Claims (10)

A first powder bonded by sintering or adhesion, and a first combined body having a recess;
A second combined body in which the second powder is bonded by sintering or adhesion, and closes the concave portion to form a cavity with the first combined body;
A plurality of heating elements arranged at intervals in a portion of the second combined body located on the cavity,
A thermal head, wherein the hollow portion is filled with a granular filler.   The thermal head according to claim 1, wherein the first powder and the second powder are made of the same material, and the first combined body and the second combined body are integrally formed.   The thermal head according to claim 1, wherein the filler is made of the same material as the particles of the first powder.   The thermal head according to claim 1, wherein the filler is made of a material having a lower thermal conductivity than the particles of the first powder.   The thermal head according to any one of claims 1 to 4, wherein the filler is made of a material having a particle diameter larger than that of the particles of the first powder.   The thermal head according to any one of claims 1 to 5, wherein the hollow portion is filled with a gas having a lower thermal conductivity than air.   The thermal head according to claim 1, wherein the inside of the hollow portion is maintained in a reduced pressure atmosphere. A method of manufacturing a thermal head according to any one of claims 1 to 7,
A first combined body forming step of forming a plurality of first bonded layers in which the first powder is selectively bonded by sintering or adhesion to form the first combined body;
A second bonded body forming step of forming a second bonded body by laminating a second bonded layer formed by selectively bonding the second powder by sintering or adhesion on the first bonded body; Have
In the first combined body forming step, the concave portion is formed by combining the first powder other than the portion located in the concave portion of the first powder to form the concave portion. .   Between the first combined body forming step and the second combined body forming step, there is a filling step of removing the first powder filled in the recess and filling the filler. The method for manufacturing a thermal head according to claim 8, wherein:   A printer comprising the thermal head according to any one of claims 1 to 7.

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