WO2023223776A1

WO2023223776A1 - Thermal print head, thermal printer, and method for manufacturing thermal print head

Info

Publication number: WO2023223776A1
Application number: PCT/JP2023/016081
Authority: WO
Inventors: 吾郎仲谷
Original assignee: ローム株式会社
Priority date: 2022-05-16
Filing date: 2023-04-24
Publication date: 2023-11-23

Abstract

According to the present invention, a thermal print head comprises a base material, a glaze layer, an electrode layer, and a resistor layer. The base material has a main surface facing a first side and a rear surface facing a second side in the thickness direction, and contains ceramic. The glaze layer is disposed on the first side in the thickness direction of the base material. The electrode layer is formed on the glaze layer. The resistor layer is formed on the glaze layer and has a plurality of heat generating parts. The base material has protrusions protruding to the first side in the thickness direction from the main surface and extending in a main scanning direction orthogonal to the thickness direction. The glaze layer has a cover part covering the protrusions. The plurality of heat generating parts overlap with the protrusions as viewed in the thickness direction.

Description

Thermal print head, thermal printer and thermal print head manufacturing method

The present disclosure relates to a thermal print head. The present disclosure also relates to a thermal printer including a thermal print head. Further, the present disclosure relates to a method of manufacturing a thermal print head.

Conventionally, a thermal print head has been used as a device that prints by applying heat to thermal paper or thermal ink ribbon. For example, Patent Document 1 discloses a conventional thermal print head. The thermal print head described in Patent Document 1 includes a substrate, a glaze layer, an electrode layer, a resistor layer, a protective layer, a driver IC, and a sealing resin. In one aspect disclosed in the document, the glaze layer includes a heat storage portion. The heat storage portion has a shape that bulges in the thickness direction of the substrate. The plurality of heat generating parts of the resistor layer are arranged on the heat storage part.

Japanese Patent Application Publication No. 2018-103608

In order to press the portion of the protective layer that covers the plurality of heat generating parts and the thermal paper etc. with stronger pressure, it is preferable to make the heat storage part more protruding from the substrate. However, it is not easy to finish the heat storage section made of glass or the like into a protruding shape. Furthermore, if the thickness of the heat storage section becomes too large, there is a risk that heat radiation from the plurality of heat generating sections will be excessively hindered. As a result, there is a concern that, for example, there may be problems such as coloring in areas that should not be printed.

An object of the present disclosure is to provide a thermal print head that is improved over conventional ones. Another object of the present disclosure is to provide a thermal printer including the thermal print head, and a method for manufacturing the thermal print head. In particular, in view of the above-mentioned circumstances, the present disclosure provides a thermal print head capable of forming a glaze layer in a more appropriate protruding shape (and a thermal printer equipped with the thermal print head, and the manufacture of the thermal print head). The first challenge is to provide a method (method).

A thermal print head provided by a first aspect of the present disclosure includes a base material including a ceramic and having a main surface facing a first side and a back surface facing a second side in the thickness direction; The device includes a glaze layer disposed on the first side in the thickness direction, an electrode layer formed on the glaze layer, and a resistor layer formed on the glaze layer and having a plurality of heat generating parts. The base material has a convex portion that protrudes from the main surface toward the first side in the thickness direction and extends in a main scanning direction perpendicular to the thickness direction. The glaze layer has a covering portion that covers the convex portion. The plurality of heat generating parts overlap with the convex part when viewed in the thickness direction.

The thermal printer provided by the second aspect of the present disclosure includes the thermal print head provided by the first aspect of the present disclosure.

A method for manufacturing a thermal print head provided by a third aspect of the present disclosure includes a step of preparing a base material containing ceramic and having a main surface facing the first side and a back surface facing the second side in the thickness direction. forming a convex portion that protrudes from the main surface toward the first side in the thickness direction, extends in a main scanning direction perpendicular to the thickness direction, and includes ceramic; and a covering portion that covers the convex portion. a step of forming an electrode layer on the glaze layer; a resistor layer having a plurality of heat generating portions overlapping the convex portions when viewed in the thickness direction on the glaze layer; and a step of forming.

According to the above configuration, in the thermal print head, the glaze layer can be shaped to protrude more appropriately.

Other features and advantages of the present disclosure will become more apparent from the detailed description given below with reference to the accompanying drawings.

FIG. 1 is a plan view showing a thermal print head according to a first embodiment of the present disclosure. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1, and shows the printer according to the first embodiment of the present disclosure. FIG. 3 is an enlarged plan view of essential parts of the thermal print head according to the first embodiment of the present disclosure. FIG. 4 is an enlarged sectional view of a main part taken along line IV-IV in FIG. 3. FIG. 5 is an enlarged cross-sectional view of main parts showing a method of manufacturing a thermal print head according to the first embodiment of the present disclosure. FIG. 6 is an enlarged cross-sectional view of main parts showing a method for manufacturing a thermal print head according to the first embodiment of the present disclosure. FIG. 7 is an enlarged cross-sectional view of main parts showing a method for manufacturing a thermal print head according to the first embodiment of the present disclosure. FIG. 8 is an enlarged sectional view of a main part showing a method for manufacturing a thermal print head according to a first embodiment of the present disclosure. FIG. 9 is an enlarged cross-sectional view of main parts showing a method for manufacturing a thermal print head according to the first embodiment of the present disclosure. FIG. 10 is an enlarged cross-sectional view of a main part showing a method for manufacturing a thermal print head according to a first embodiment of the present disclosure. FIG. 11 is an enlarged sectional view of a main part showing a first modification of the thermal print head according to the first embodiment of the present disclosure. FIG. 12 is an enlarged cross-sectional view of main parts showing a thermal print head according to a second embodiment of the present disclosure. FIG. 13 is an enlarged cross-sectional view of main parts showing a first modification of the thermal print head according to the second embodiment of the present disclosure.

Hereinafter, preferred embodiments of the present disclosure will be specifically described with reference to the drawings.

Terms such as "first," "second," and "third" in the present disclosure are used merely for identification purposes and are not intended to impose any order on these objects.

In this disclosure, "a thing A is formed on a thing B" and "a thing A is formed on a thing B" mean "a thing A is formed on a thing B" unless otherwise specified. "It is formed directly on object B," and "It is formed on object B, with another object interposed between object A and object B." Similarly, "something A is placed on something B" and "something A is placed on something B" mean "something A is placed on something B" unless otherwise specified. This includes ``directly placed on object B'' and ``placed on object B with another object interposed between object A and object B.'' Similarly, "a certain object A is located on a certain object B" means, unless otherwise specified, "a certain object A is in contact with a certain object B, and a certain object A is located on a certain object B." ``The fact that a certain thing A is located on a certain thing B while another thing is interposed between the certain thing A and the certain thing B.'' In addition, "a certain object A overlaps a certain object B when viewed in a certain direction" means, unless otherwise specified, "a certain object A overlaps all of a certain object B" and "a certain object A overlaps with a certain object B". This includes "overlapping a part of something B." Furthermore, in the present disclosure, "a certain surface A faces (one side or the other side of) the direction B" is not limited to the case where the angle of the surface A with respect to the direction B is 90 degrees; Including cases where it is tilted to the opposite direction.

1 to 4 show a thermal print head A1 and a thermal printer P1 according to a first embodiment of the present disclosure. The thermal print head A1 includes a substrate 1, a protective layer 2, an electrode layer 3, a resistor layer 4, a connection substrate 5, a plurality of

wires

61 and 62, a plurality of driver ICs 7, a protective resin 78, and a heat dissipation member 8. The thermal print head A1 is incorporated into a thermal printer P1 that prints on a print medium C1 (see FIG. 2).

The thermal printer P1 includes a thermal print head A1 and a platen roller B1. The platen roller B1 directly faces the thermal print head A1. The print medium C1 is sandwiched between the thermal print head A1 and the platen roller B1, and is conveyed in the sub-scanning direction y by the platen roller B1. Examples of such print media C1 include thermal paper for creating barcode sheets and receipts. A flat rubber platen may be used instead of the platen roller B1. This platen includes a portion of a cylindrical rubber having a large radius of curvature that is arch-shaped in cross-section.

FIG. 1 is a plan view showing the thermal print head A1. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1, and shows the printer according to the first embodiment of the present disclosure. FIG. 3 is an enlarged plan view of the main parts of the thermal print head A1. FIG. 4 is an enlarged sectional view of a main part taken along line IV-IV in FIG. 3. In FIG. 1, the protective layer 2 and the plurality of

wires

61 and 62 are omitted. In FIG. 3, the protective layer 2 is omitted, and the electrode layer 3 is hatched.

In these figures, the thickness direction of the substrate 1 (substrate 11 described below) is defined as the thickness direction z. The z1 side in the thickness direction z is an example of a "first side," and the z2 side is an example of a "second side." The main scanning direction x and the sub-scanning direction y are both directions orthogonal to the thickness direction z, and are orthogonal to each other. During printing, the print medium C1 is sent from the y2 side to the y1 side in the sub-scanning direction y. In the sub-scanning direction y, the y1 side is sometimes referred to as downstream, and the y2 side is sometimes referred to as upstream.

As shown in FIG. 1, the substrate 1 has a plate shape that extends long in the main scanning direction x. The substrate 1 is a support member that supports a protective layer 2 , an electrode layer 3 , a resistor layer 4 , and a plurality of driver ICs 7 . Substrate 1 has base material 11 and glaze layer 12 .

The base material 11 includes ceramics such as AlN (aluminum nitride), Al ₂ O ₃ (alumina), and zirconia, and has these ceramics as its main component. The thickness of the base material 11 is, for example, 0.6 mm or more and 1.0 mm or less. As shown in FIG. 1, the base material 11 has a rectangular shape that extends in the main scanning direction x when viewed from above. The base material 11 has a first main surface 11a, a first back surface 11b, and a convex portion 111.

The first main surface 11a and the first back surface 11b are spaced apart in the thickness direction z. The first main surface 11a faces the z1 side in the thickness direction z. The first back surface 11b faces the z2 side in the thickness direction z. The first main surface 11a is an example of a "main surface", and the first back surface 11b is an example of a "back surface".

As shown in FIG. 4, the convex portion 111 protrudes from the first main surface 11a toward the z1 side in the thickness direction z. As shown in FIG. 3, the convex portion 111 extends in the main scanning direction x. The shape and size of the convex portion 111 are not limited at all. As shown in FIG. 4, the convex portion 111 of this example includes a first portion 1111 and a second portion 1112.

The first portion 1111 is a portion that protrudes from the first main surface 11a. The second portion 1112 is a portion located on the z1 side in the thickness direction z with respect to the first portion 1111. A first dimension W1, which is the size of the first portion 1111 in the sub-scanning direction y, is larger than a second dimension W2, which is the size of the second portion 1112 in the sub-scanning direction y. The relationship between the first dimension W1 and the second dimension W2 is not limited at all, and for example, the second dimension W2 is 50% or more and 95% or less of the first dimension W1.

The thickness Z1 of the first part 1111 and the thickness Z2 of the second part 1112 are not limited at all. The thickness Z1 may be larger than or smaller than the thickness Z2, or may be the same size. A specific example of the thickness Z1 and the thickness Z2 is, for example, 30 μm or more and 200 μm or less.

The cross-sectional shape of the first portion 1111 perpendicular to the main scanning direction x is not limited in any way, and in the illustrated example, it is rectangular. The cross-sectional shape of the second portion 1112 perpendicular to the main scanning direction x is not limited in any way, and in the illustrated example, it is rectangular.

The glaze layer 12 is arranged on the z1 side of the base material 11 in the thickness direction z. The glaze layer 12 covers at least a portion of the first main surface 11a and the convex portion 111. Glaze layer 12 is made of a glass material such as amorphous glass. The glaze layer 12 of this example includes a covering portion 122 and a flat portion 121.

The covering portion 122 covers at least a portion of the convex portion 111. In the illustrated example, the covering portion 122 covers all of the convex portions 111 . Note that the covering portion 122 may be configured to cover only a portion of the convex portion 111. For example, a region of the convex portion 111 where the electrode layer 3 and resistor layer 4 described below are not formed may be exposed from the covering portion 122. Alternatively, if the surface properties of the convex portion 111 are such that the electrode layer 3 and the resistor layer 4 can be formed, a portion of the electrode layer 3 and the resistor layer 4 may be in contact with the convex portion 111. .

The covering portion 122 extends long in the main scanning direction x. The covering portion 122 bulges in the thickness direction z when viewed in the main scanning direction x. The surface of the covering portion 122 has a curved cross-sectional shape perpendicular to the main scanning direction x that bulges toward the z1 side in the thickness direction z. The covering portion 122 is provided to make it easier to press a heat generating portion (a heat generating portion 41 to be described later) of the resistor layer 4 against the print medium C1. The thickness of the covering portion 122 is not limited at all, and is, for example, 5 μm or more and 15 μm or less.

The flat portion 121 is formed adjacent to the covering portion 122, and has a flat surface on the z1 side in the thickness direction z. The thickness of the flat portion 121 is, for example, about 2.0 μm. The flat portion 121 is for forming a smooth surface suitable for forming the electrode layer 3 by covering the first main surface 11a of the base material 11, which is a relatively rough surface.

The softening point of the glaze layer 12 is not limited at all. The softening point of the flat portion 121 and the softening point of the covering portion 122 may be different from each other or may be the same. The softening point of the flat portion 121 and the covering portion 122 is, for example, 800° C. or higher and 850° C. or lower, or approximately 680° C., for example.

The electrode layer 3 constitutes a conduction path for supplying current to the resistor layer 4. The electrode layer 3 is made of a conductive material. The electrode layer 3 is, for example, a metal containing Au (gold). The electrode layer 3 is formed on the glaze layer 12 of the substrate 1. The thickness of the electrode layer 3 is, for example, 1 μm or more and 7.5 μm or less (preferably about 5.0 μm). The electrode layer 3 has a common electrode 31 and a plurality of individual electrodes 34, as shown in FIGS. 3 and 4. Note that the shape and arrangement of each part of the electrode layer 3 are not limited to the examples shown in FIGS. 3 and 4, and can have various configurations. Moreover, the material of each part of the electrode layer 3 is not limited at all.

As shown in FIG. 3, the common electrode 31 has a plurality of strip portions 32 and connecting portions 33. The connecting portion 33 is disposed near the edge of the substrate 1 on the y1 side in the sub-scanning direction y, and has a band shape extending in the main scanning direction x. The plurality of strips 32 each extend from the connecting portion 33 in the sub-scanning direction y, and are arranged at equal pitches in the main-scanning direction x. In the example shown in FIG. 3, the auxiliary layer 331 is laminated on the connecting portion 33 in order to reduce the resistance value of the connecting portion 33, but the auxiliary layer 331 does not need to be laminated. The auxiliary layer 331 is formed, for example, by printing and baking a paste containing an organic Ag (silver) compound or a paste containing Ag (silver) particles, glass frit, Pd (palladium), and a resin.

The plurality of individual electrodes 34 are for partially supplying current to the resistor layer 4. Each individual electrode 34 has opposite polarity to the common electrode 31. Each individual electrode 34 extends from the resistor layer 4 toward the driver IC 7. The plurality of individual electrodes 34 are arranged in the main scanning direction x. Each of the plurality of individual electrodes 34 has a strip portion 35, a connecting portion 36, and a bonding portion 37.

As shown in FIG. 3, the strip portion 35 extends in the sub-scanning direction y, and is strip-shaped when viewed in the thickness direction z. Each strip 35 is located between two adjacent strips 32 of the common electrode 31 . The distance between the adjacent strip portions 35 of the individual electrodes 34 and the strip portions 32 of the common electrode 31 is, for example, 50 μm or less.

The connecting portion 36 is a portion extending from the strip portion 35 toward the driver IC 7. The connecting portion 36 includes a parallel portion 361 and an oblique portion 362. The parallel portion 361 has one end connected to the bonding portion 37 and extends along the sub-scanning direction y. The oblique portion 362 is inclined with respect to the sub-scanning direction y. The oblique portion 362 is sandwiched between the parallel portion 361 and the strip portion 35 in the sub-scanning direction y. Further, the plurality of individual electrodes 34 are integrated into the driver IC 7.

As shown in FIG. 3, the plurality of bonding parts 37 are formed at the ends of the individual electrodes 34 on the y2 side in the sub-scanning direction y, and are each connected to each parallel part 361. Each wire 61 is bonded to each bonding portion 37 . As a result, each individual electrode 34 and the driver IC 7 are electrically connected via each wire 61. The plurality of bonding parts 37 include a first bonding part 37A and a second bonding part 37B. The width (length in the main scanning direction x) of the parallel portion 361 sandwiched between two adjacent first bonding portions 37A is, for example, 10 μm or less. Further, the second bonding portion 37B is located further away from the resistor layer 4 than the first bonding portion 37A in the sub-scanning direction y. The second bonding portion 37B is connected to a parallel portion 361 sandwiched between two adjacent first bonding portions 37A. With such a configuration, the plurality of bonding parts 37 are prevented from interfering with each other, even though the width is wider than most parts of the connecting part 36. The portion of the connecting portion 36 sandwiched between the adjacent first bonding portions 37A has the smallest width in the individual electrode 34.

The resistor layer 4 is formed using a material having a higher resistivity than the material forming the electrode layer 3. The resistor layer 4 contains, for example, ruthenium oxide. In this example, the resistor layer 4 is formed on the covering portion 122, as shown in FIGS. 3 and 4. The shape of the resistor layer 4 when viewed in the thickness direction z is not limited at all, and in this embodiment, as shown in FIGS. 1 and 3, it is a band shape extending in the main scanning direction x. The resistor layer 4 straddles each strip portion 32 (common electrode 31) and each strip portion 35 (individual electrode 34). The resistor layer 4 is laminated on the z1 side of the plurality of strips 32 and the plurality of strips 35 in the thickness direction z.

A portion of the resistor layer 4 sandwiched between each strip portion 32 and each strip portion 35 serves as a heat generating portion 41 . The plurality of heat generating parts 41 generate heat by being partially energized by the electrode layer 3 . Print dots are formed by the heat generated by each heat generating section 41. The plurality of heat generating parts 41 are arranged in the main scanning direction x. The greater the number of heat generating parts 41 arranged in the main scanning direction x in the unit length (for example, 1 mm) of the substrate 1 in the main scanning direction x, the greater the dot density of the thermal print head A1. The plurality of heat generating parts 41 overlap with the convex part 111 when viewed in the thickness direction z. Further, in this example, the plurality of 41 overlap the first portion 1111 when viewed in the thickness direction z.

The thickness of the resistor layer 4 is, for example, 3 μm or more and 6 μm or less. The material and thickness of the resistor layer 4 are not limited.

The protective layer 2 is for protecting the electrode layer 3, the resistor layer 4, and the like. The protective layer 2 may have a single layer structure, or may have a structure in which a plurality of layers are laminated. The material of the protective layer 2 is not limited at all. An example of the protective layer 2 includes, for example, amorphous glass as a main component. In another example of the protective layer 2, a first layer made of amorphous glass and a second layer made of SiAlON, for example, may be laminated. SiAlON is a silicon nitride-based engineering ceramic made by synthesizing Si ₃ N ₄ (silicon nitride) with Al ₂ O ₃ (alumina) and SiO ₂ (silica). The second layer is formed by sputtering, for example. The second layer may be made of SiC (silicon carbide) instead of SiAlON.

As shown in FIGS. 1 and 2, the connection board 5 is arranged on the upstream side in the sub-scanning direction y with respect to the board 1. The connection board 5 is, for example, a printed circuit board, and has a wiring pattern (not shown) formed thereon. A connector 59, which will be described later, is mounted on the connection board 5. Although the shape of the connection board 5 is not particularly limited, in this embodiment, it is a rectangular shape whose longitudinal direction is the main scanning direction x. The connection board 5 has a second main surface 5a and a second back surface 5b. The second main surface 5a is a surface facing the same side as the first main surface 11a of the base material 11, and the second back surface 5b is a surface facing the same side as the first back surface 11b of the base material 11.

The plurality of driver ICs 7 are each mounted on, for example, the substrate 1, and are used to individually energize the plurality of heat generating parts 41. Each driver IC 7 may be mounted across the board 1 and the connection board 5, or may be mounted on the connection board 5. The plurality of driver ICs 7 are connected to the plurality of individual electrodes 34 (the plurality of bonding parts 37) by the plurality of wires 61. The power supply control to the plurality of heat generating parts 41 by the plurality of driver ICs 7 follows a command signal inputted from the outside of the thermal print head A1 via the connection board 5. The plurality of driver ICs 7 are connected to a wiring pattern (not shown) of the connection board 5 by a plurality of wires 62. The plurality of driver ICs 7 are provided as appropriate depending on the number of the plurality of heat generating parts 41.

The plurality of driver ICs 7, the plurality of wires 61, and the plurality of wires 62 are covered with a protective resin 78. The protective resin 78 is made of, for example, an insulating resin and is, for example, black in color. The protective resin 78 is formed so as to straddle the substrate 1 and the connection substrate 5.

The connector 59 is used to connect the thermal print head A1 to a thermal printer. The connector 59 is attached to the connection board 5 and connected to a wiring pattern (not shown) on the connection board 5.

The heat dissipation member 8 supports the substrate 1 and the connection substrate 5, as shown in FIG. The heat radiating member 8 is for radiating a part of the heat generated by the plurality of heat generating parts 41 to the outside via the substrate 1. The heat radiation member 8 is a block-shaped member made of metal such as Al, for example. The heat dissipation member 8 has a support surface 81, as shown in FIG. Each of the support surfaces 81 faces upward in the thickness direction z. The first back surface 11b of the base material 11 and the second back surface 5b of the connection board 5 are joined to the support surface 81.

Next, a method for manufacturing the thermal print head A1 will be described below with reference to FIGS. 5 to 10.

First, as shown in FIG. 5, a base material 11 is prepared. The base material 11 at this point has the first main surface 11a and the first back surface 11b, and does not have the convex portion 111 yet. Further, the base material 11 at this point may be a hardened ceramic, or may be a green body that hardens as a ceramic by being fired. In addition, in the following explanation, for convenience of understanding, an example will be explained in which members for forming one thermal print head A1 are sequentially formed. The members for forming may be formed all at once. In this case, the step of dividing the base material 11 and the like are performed as appropriate. In addition, in the step of dividing the base material 11, the glaze layer 12 may be divided all at once, or the glaze layer 12 may be formed in a region of the base material 11 that avoids the divided region.

Next, as shown in FIG. 6, a first portion 1111 is formed. The method of forming the first part 1111 is not limited at all. An example of a method for forming the first portion 1111 is a 3D printing method using ceramic stereolithography technology. The 3D printing method is a method in which a ceramic filler is selectively photopolymerized to form a three-dimensional structure. An example of a device that implements such a 3D printing method is a device manufactured by Lithoz.

For example, a slurry containing a photocurable resin binder and ceramic powder is applied to a transparent container. The first main surface 11a of the base material 11 is brought into contact with this slurry from above. In this state, a visible image corresponding to the shape of the first portion 1111 (the size in the sub-scanning direction y extending in the main-scanning direction x is a band shape of the first dimension W1) seen in the thickness direction z through the transparent container. Expose the slurry to light. The exposed slurry becomes a ceramic green body that is to become the first part 1111 and adheres to the first main surface 11a. At this time, the thickness Z1 is, for example, 30 μm or more and 200 μm or less.

Next, a new slurry is applied to the container, and the green body that is to become the first part 1111 is brought into contact with it. In this state, the shape of the second portion 1112 corresponds to the shape of the second portion 1112 seen in the thickness direction z through the transparent container (a band-like shape extending in the main scanning direction x and having a second dimension W2 in the sub-scanning direction y). Expose the slurry to visible light. As a result, as shown in FIG. 7, the exposed slurry becomes a ceramic green body that is to become the second part 1112 and adheres to the first part 1111. At this time, the thickness Z2 is, for example, 30 μm or more and 200 μm or less.

Next, the base material 11 on which the green bodies that are to become the first part 1111 and the second part 1112 are formed is subjected to a firing treatment or the like. Thereby, the base material 11 having the convex portions 111 is obtained. The convex portion 111 includes a first portion 1111 and a second portion 1112.

Next, as shown in FIG. 8, a glaze layer 12 is formed. To form the glaze layer 12, for example, a paste containing glass is applied so as to cover the first main surface 11a and the convex portions 111. Next, this glass paste is fired. As a result, a glaze layer 12 including a flat portion 121 and a covering portion 122 is obtained.

Next, as shown in FIG. 9, the electrode layer 3 is formed. The electrode layer 3 is formed by, for example, applying a paste containing resinate Au (gold) on the glaze layer 12 and baking it, thereby forming a metal layer containing Au (gold). The electrode layer 3 is obtained by subjecting this metal layer to patterning such as etching. Alternatively, the auxiliary layer 331 may be formed by printing and baking a paste containing Ag (silver).

Next, as shown in FIG. 10, a resistor layer 4 is formed. The resistor layer 4 is formed by, for example, applying a paste containing ruthenium oxide in a strip shape extending in the main scanning direction x, and firing the paste. Thereafter, the thermal print head A1 is obtained by forming the protective layer 2, mounting the driver IC 7, bonding the

wires

61 and 62, and attaching the substrate 1 and the connection substrate 5 to the heat dissipating member 8.

Next, the functions of the thermal print head A1 and the thermal printer P1 will be explained.

According to the present embodiment, the base material 11 has a convex portion 111 that protrudes from the first main surface 11a toward the z1 side in the thickness direction z. The covering portion 122 of the glaze layer 12 covers the convex portion 111 . This allows the glaze layer 12 (covering portion 122) to have a more protruding shape than when the glaze layer 12 is formed only with glass or the like on the flat first main surface 11a. Furthermore, the covering portion 122 only needs to have a thickness that covers the convex portion 111 . This prevents problems such as the thickness of the glaze layer 12 (covering portion 122) becoming excessively large, which excessively impedes heat dissipation from the plurality of heat generating parts 41, causing color development in areas that should not be printed. can do.

The convex portion 111 includes a first portion 1111 and a second portion 1112. The second dimension W2 of the second portion 1112 is smaller than the first dimension W1 of the first portion 1111. Thereby, the convex portion 111 has a so-called stepped shape. Therefore, the covering portion 122 can be shaped to bulge out more on the z1 side in the thickness direction z.

The cross-sectional shapes of the first part 1111 and the second part 1112 are rectangular. For example, when forming the convex portion 111 by the above-mentioned 3D printing method, exposure to form a green body to become the first part 1111 and exposure to form a green body to become the second part 1112 are performed. , it is sufficient to perform two exposures. Therefore, the manufacturing efficiency of the thermal print head A1 can be improved compared to a shape that requires multiple exposures.

11-13 illustrate variations and other embodiments of the present disclosure. In addition, in these figures, the same or similar elements as in the above embodiment are given the same reference numerals as in the above embodiment. Furthermore, the configurations of each part in each modification and each embodiment can be combined with each other as appropriate within a range that does not cause technical contradiction.

FIG. 11 shows a first modification of the thermal print head A1. In the thermal print head A11 of this example, the cross-sectional shapes of the first portion 1111 and the second portion 1112 perpendicular to the main scanning direction x are different from those of the above-mentioned example.

The cross-sectional shapes of the first portion 1111 and the second portion 1112 of this modification perpendicular to the main scanning direction x are trapezoidal. The first dimension W1 and thickness Z1 of the first portion 1111 and the second dimension W2 and thickness Z2 of the second portion 1112 are not limited at all and are, for example, similar to the dimensions of the thermal print head A1.

The first part 1111 and the second part 1112 of this example can be formed by the 3D printing method exemplified in the method for manufacturing the thermal print head A1 described above. In forming each of the first part 1111 and the second part 1112, the above-described slurry application and exposure are repeated multiple times. At this time, the coating thickness of the slurry is significantly thinner than the coating thickness in the method for manufacturing the thermal print head A1. Further, each time coating and exposure are repeated, the size of the area to be exposed in the sub-scanning direction y is gradually reduced. As a result, a trapezoidal first portion 1111 and second portion 1112 are obtained. Note that depending on the coating thickness of the slurry, the exposure state, etc., the side surfaces of the first portion 1111 and the second portion 1112 on both sides in the sub-scanning direction y may have a microscopically step-like shape.

According to this modification as well, the glaze layer 12 can be shaped to protrude more appropriately. Further, as understood from this modification, the specific shapes of the first portion 1111 and the second portion 1112 are not limited at all. Since the first portion 1111 and the second portion 1112 are trapezoidal, the covering portion 122 can be finished into a more gently bulging shape.

FIG. 12 shows a thermal print head according to a second embodiment of the present disclosure. The thermal print head A2 of this embodiment is different from the above-described embodiments in the configuration of the convex portion 111.

The convex portion 111 of this embodiment includes a first portion 1111, a second portion 1112, and a third portion 1113. The third portion 1113 is disposed on the z1 side in the thickness direction z with respect to the second portion 1112. The size and shape of the third portion 1113 are not limited at all. In the illustrated example, the third dimension W3, which is the size of the third portion 1113 in the sub-scanning direction y, is smaller than the second dimension W2. For example, the third dimension W3 is 50% or more and 95% or less of the second dimension W2. The thickness Z3 of the third portion 1113 is not limited at all, and may be different from or the same as the thickness Z1 and the thickness Z2, and is, for example, 30 μm or more and 200 μm or less. The cross-sectional shape of the third portion 1113 is not limited in any way, and in the illustrated example, it is rectangular.

The formation of the convex portion 111 including the third portion 1113 can be performed, for example, in the above-mentioned 3D printing method, after forming the green body to become the second portion 1112, the green body to become the third portion 1113 is formed by the same process. Form. Then, by performing the above-described firing treatment or the like, the base material 11 having the convex portion 111 including the first portion 1111, the second portion 1112, and the third portion 1113 can be formed.

According to this embodiment as well, the glaze layer 12 can be shaped to protrude more appropriately. Further, since the convex portion 111 includes the third portion 1113 in addition to the first portion 1111 and the second portion 1112, the shape of the covering portion 122 can be finished in a shape that protrudes more on the z1 side in the thickness direction z. . Further, as understood from this embodiment, the convex portion 111 is limited to a configuration including a first portion 1111, a second portion 1112, and a configuration including a first portion 1111, a second portion 1112, and a third portion 1113. For example, the structure may include only the first portion 1111, or may include a portion forming a further step on the z1 side of the third portion 1113 in the thickness direction z.

FIG. 13 shows a first modification of the thermal print head A2. In the thermal print head A21 of this example, the cross-sectional shapes of the first portion 1111, the second portion 1112, and the third portion 1113 perpendicular to the main scanning direction x are different from those of the above-mentioned example.

The first section 1111, second section 1112, and third section 1113 of this modification have a trapezoidal cross-sectional shape perpendicular to the main scanning direction x. The first dimension W1 and thickness Z1 of the first part 1111, the second dimension W2 and thickness Z2 of the second part 1112, and the third dimension W3 and thickness Z3 of the third part 1113 are not limited in any way, and for example, The dimensions are similar to those of the thermal print head A2.

According to this modification as well, the glaze layer 12 can be shaped to protrude more appropriately. Further, the cross-sectional shapes of the first part 1111, the second part 1112, and the third part 1113 may all be rectangular or trapezoidal, or one of them may be rectangular and the other one may be trapezoidal or the like. It may be a combination.

The thermal print head, thermal printer, and method for manufacturing a thermal print head according to the present disclosure are not limited to the embodiments described above. The specific configurations of the thermal print head, thermal printer, and method of manufacturing the thermal print head according to the present disclosure can be modified in various designs. The present disclosure includes the embodiments described in the appendix below.

Additional note 1.
A base material containing ceramic and having a main surface facing the first side and a back surface facing the second side in the thickness direction;
a glaze layer disposed on the first side of the base material in the thickness direction;
an electrode layer formed on the glaze layer;
a resistor layer formed on the glaze layer and having a plurality of heat generating parts,
The base material has a convex portion that protrudes from the main surface to the first side in the thickness direction and extends in a main scanning direction perpendicular to the thickness direction,
The glaze layer has a covering portion that covers the convex portion,
In the thermal print head, the plurality of heat generating parts overlap with the convex part when viewed in the thickness direction.
Appendix 2.
The convex portion includes a first portion and a second portion located on the first side in the thickness direction with respect to the first portion,
A first dimension, which is a size of the first part in the thickness direction and a sub-scanning direction perpendicular to the main scanning direction, is larger than a second dimension, which is a size of the second part in the sub-scanning direction. , the thermal print head described in Appendix 1.
Appendix 3.
The thermal print head according to appendix 2, wherein the second dimension is 50% or more and 95% or less of the first dimension.
Appendix 4.
The thermal print head according to

appendix

2 or 3, wherein the first part has a rectangular cross-sectional shape perpendicular to the main scanning direction.
Appendix 5.
The thermal print head according to appendix 4, wherein the second portion has a rectangular cross-sectional shape perpendicular to the main scanning direction.
Appendix 6.
The thermal print head according to

appendix

2 or 3, wherein the first part has a trapezoidal cross-sectional shape perpendicular to the main scanning direction.
Appendix 7.
The thermal print head according to appendix 6, wherein the second portion has a trapezoidal cross-sectional shape perpendicular to the main scanning direction.
Appendix 8.
8. The thermal print head according to any one of appendices 2 to 7, wherein the first portion has a thickness in the thickness direction of 30 μm or more and 200 μm or less.
Appendix 9.
The thermal print head according to appendix 8, wherein the second portion has a thickness in the thickness direction of 30 μm or more and 200 μm or less.
Appendix 10.
The convex portion further includes a third portion located on the first side in the thickness direction with respect to the second portion,
The thermal print head according to any one of appendixes 2 to 9, wherein a third dimension, which is a size of the third portion in the sub-scanning direction, is smaller than the second dimension.
Appendix 11.
The thermal print head according to appendix 10, wherein the third portion has a rectangular cross-sectional shape perpendicular to the main scanning direction.
Appendix 12.
The thermal print head according to appendix 10, wherein the third portion has a trapezoidal cross-sectional shape perpendicular to the main scanning direction.
Appendix 13.
The thermal print head according to any one of appendices 10 to 12, wherein the third portion has a thickness in the thickness direction of 30 μm or more and 200 μm or less.
Appendix 14.
The surface of the coating portion of the glaze layer has a cross-sectional shape perpendicular to the main scanning direction that is curved so as to bulge toward the first side in the thickness direction. print head.
Appendix 15.
The electrode layer includes a common electrode having a plurality of strips and a plurality of individual electrodes,
15. The thermal print head according to any one of appendices 1 to 14, wherein the plurality of strips and the plurality of individual electrodes are alternately arranged in the main scanning direction.
Appendix 16.
The thermal print head according to appendix 15, wherein the resistor layer has a band shape extending in the main scanning direction, spanning the plurality of band-shaped portions and the plurality of individual electrodes.
Appendix 17.
A thermal printer comprising the thermal print head according to any one of appendices 1 to 16.
Appendix 18.
preparing a base material containing ceramic and having a main surface facing the first side and a back surface facing the second side in the thickness direction;
forming a convex portion that protrudes from the main surface toward the first side in the thickness direction, extends in a main scanning direction perpendicular to the thickness direction, and includes ceramic;
forming a glaze layer having a covering portion covering the convex portion;
forming an electrode layer on the glaze layer;
A method for manufacturing a thermal print head, comprising: forming on the glaze layer a resistor layer having a plurality of heat generating parts that overlap with the convex parts when viewed in the thickness direction.

A1, A11, A2, A21: Thermal print head P1: Thermal printer 1: Substrate 2: Protective layer 3: Electrode layer 4: Resistor layer 5: Connection board 5a: Second main surface 5b: Second back surface 7: Driver IC 8: Heat radiation member 11: Base material 11a: First main surface (main surface)
11b: First back surface (back surface) 12: Glaze layer 31: Common electrode 32: Strip portion 33: Connecting portion 34: Individual electrode 35: Strip portion 36: Connecting portion 37: Bonding portion 37A: First bonding portion 37B: Second Bonding part 41: Heat generating part 59: Connector 61, 62: Wire 78: Protective resin 81: Support surface 111: Convex part 121: Flat part 122: Covering part 331: Auxiliary layer 361: Parallel part 362: Oblique part 1111: No. 1 part 1112: 2nd part 1113: 3rd part B1: Platen roller C1: Print medium W1: First dimension W2: Second dimension W3: Third dimension Z1, Z2, Z3: Thickness x: Main scanning direction y: Sub-scanning direction z: Thickness direction

Claims

A base material containing ceramic and having a main surface facing the first side and a back surface facing the second side in the thickness direction;
a glaze layer disposed on the first side of the base material in the thickness direction;
an electrode layer formed on the glaze layer;
a resistor layer formed on the glaze layer and having a plurality of heat generating parts,
The base material has a convex portion that protrudes from the main surface to the first side in the thickness direction and extends in a main scanning direction perpendicular to the thickness direction,
The glaze layer has a covering portion that covers the convex portion,
In the thermal print head, the plurality of heat generating parts overlap with the convex part when viewed in the thickness direction.
The convex portion includes a first portion and a second portion located on the first side in the thickness direction with respect to the first portion,
A first dimension, which is a size of the first part in the thickness direction and a sub-scanning direction perpendicular to the main scanning direction, is larger than a second dimension, which is a size of the second part in the sub-scanning direction. , The thermal print head according to claim 1.
The thermal print head according to claim 2, wherein the second dimension is 50% or more and 95% or less of the first dimension.
The thermal print head according to claim 2 or 3, wherein the first portion has a rectangular cross-sectional shape perpendicular to the main scanning direction.
The thermal print head according to claim 4, wherein the second portion has a rectangular cross-sectional shape perpendicular to the main scanning direction.
The thermal print head according to claim 2 or 3, wherein the first portion has a trapezoidal cross-sectional shape perpendicular to the main scanning direction.
The thermal print head according to claim 6, wherein the second portion has a trapezoidal cross-sectional shape perpendicular to the main scanning direction.
The thermal print head according to any one of claims 2 to 7, wherein the first portion has a thickness in the thickness direction of 30 μm or more and 200 μm or less.
The thermal print head according to claim 8, wherein the thickness of the second portion in the thickness direction is 30 μm or more and 200 μm or less.
The convex portion further includes a third portion located on the first side in the thickness direction with respect to the second portion,
10. The thermal print head according to claim 2, wherein a third dimension of the third portion in the sub-scanning direction is smaller than the second dimension.
The thermal print head according to claim 10, wherein the third portion has a rectangular cross-sectional shape perpendicular to the main scanning direction.
The thermal print head according to claim 10, wherein the third portion has a trapezoidal cross-sectional shape perpendicular to the main scanning direction.
The thermal print head according to any one of claims 10 to 12, wherein the thickness of the third portion in the thickness direction is 30 μm or more and 200 μm or less.
14. The surface of the covering portion of the glaze layer has a cross-sectional shape perpendicular to the main scanning direction that is curved so as to bulge toward the first side in the thickness direction. thermal print head.
The electrode layer includes a common electrode having a plurality of strips and a plurality of individual electrodes,
15. The thermal print head according to claim 1, wherein the plurality of strips and the plurality of individual electrodes are alternately arranged in the main scanning direction.
16. The thermal print head according to claim 15, wherein the resistor layer has a band shape that extends in the main scanning direction and straddles the plurality of band parts and the plurality of individual electrodes.
A thermal printer comprising the thermal print head according to any one of claims 1 to 16.
preparing a base material containing ceramic and having a main surface facing the first side and a back surface facing the second side in the thickness direction;
forming a convex portion that protrudes from the main surface toward the first side in the thickness direction, extends in a main scanning direction perpendicular to the thickness direction, and includes ceramic;
forming a glaze layer having a covering portion covering the convex portion;
forming an electrode layer on the glaze layer;
A method for manufacturing a thermal print head, comprising: forming on the glaze layer a resistor layer having a plurality of heat generating parts that overlap with the convex parts when viewed in the thickness direction.