CN114801503A

CN114801503A - Thermal print head, thermal printer, and method for manufacturing thermal print head

Info

Publication number: CN114801503A
Application number: CN202210067206.0A
Authority: CN
Inventors: 仲谷吾郎; 藤田明良
Original assignee: Rohm Co Ltd
Current assignee: Rohm Co Ltd
Priority date: 2021-01-21
Filing date: 2022-01-20
Publication date: 2022-07-29

Abstract

The invention provides a thermal print head, a thermal printer and a method for manufacturing the thermal print head, which can inhibit the occurrence of the adhesion phenomenon. The thermal print head (A1) includes: a base (10) having a main surface (11) facing in the thickness direction (z); a resistor layer (4) which is arranged on the main surface (11) and includes a plurality of heat generation sections (41) arranged in the main scanning direction (x); an electrode layer which is arranged on the main surface (11) and forms a conduction path for conducting electricity to the plurality of heat generation parts (41); and a protective layer (2) covering the resistor layer (4) and the electrode layer. The protective layer (2) has a first region (21) that overlaps the plurality of heat generation portions (41) when viewed in the thickness direction (z) and extends in the main scanning direction (x) when viewed in the thickness direction (z). The first region (21) has a plurality of first concave sections (22) and a plurality of first convex sections (23) that are alternately arranged along the main scanning direction (x).

Description

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

Technical Field

The invention relates to a thermal print head, a thermal printer, and a method of manufacturing the thermal print head.

Background

Patent document 1 discloses an example of a conventional thermal print head. The thermal print head disclosed in this document includes a substrate, a glaze layer, a plurality of electrodes, a heating resistor, and a protective layer. The glaze layer is made of, for example, glass and is formed on the substrate. A plurality of electrodes are formed on the glaze layer. The plurality of electrodes are members for supplying electricity to the heating resistor. The heating resistor is a heating source and is stacked on the glaze layer via a plurality of electrodes. The protective layer covers the plurality of electrodes and the heating resistor.

In such a thermal head, a print medium such as thermal paper is pressed against the heating resistor by the platen roller. Then, dots are printed on a printing medium such as thermal paper by heat from the heating resistor. The print medium is conveyed in the sub-scanning direction by the rotation of the platen roller.

Documents of the prior art

Patent document

Patent document 1: japanese patent application laid-open No. 2011-240641.

Disclosure of Invention

Problems to be solved by the invention

For example, in the case of printing on thermal paper, a sticking phenomenon in which the thermal paper is unnecessarily stuck to the thermal head may occur. When the blocking phenomenon occurs, the thermal paper cannot be smoothly conveyed, resulting in a reduction in printing quality.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a thermal print head capable of suppressing the occurrence of the sticking phenomenon.

Means for solving the problems

According to a first aspect of the present invention, there is provided a thermal print head comprising: a substrate having a main surface facing one side in a thickness direction; a resistor layer which is arranged on the main surface and includes a plurality of heat generation portions arranged in a main scanning direction; an electrode layer disposed on the main surface and constituting a conduction path for conducting electricity to the plurality of heat generating portions; and a protective layer covering the resistor layer and the electrode layer, the protective layer having a first region overlapping the plurality of heat generating portions as viewed in the thickness direction and extending in a main scanning direction as viewed in the thickness direction, the first region having a plurality of first concave portions and a plurality of first convex portions alternately arranged along the main scanning direction.

According to a second aspect of the present invention, there is provided a thermal printer comprising the thermal print head provided by the first aspect and a platen facing the thermal print head.

According to a third aspect of the present invention, there is provided a method of manufacturing a thermal head, comprising: preparing a base material having a main surface facing one side in a thickness direction; forming a resistor layer which is arranged on the main surface and includes a plurality of heat generating portions arranged in a main scanning direction; forming an electrode layer which is arranged on the main surface and constitutes a conduction path to the plurality of heat generating portions; and forming a protective layer covering the resistor layer and the electrode layer, the protective layer having a first region that overlaps the plurality of heat generating portions when viewed in the thickness direction and extends in a main scanning direction when viewed in the thickness direction, the first region having a plurality of first recesses and a plurality of first projections that are alternately arranged along the main scanning direction.

Effects of the invention

According to the thermal printing head of the invention, the occurrence of the adhesion phenomenon can be inhibited. In addition, according to the thermal printer of the present invention, the occurrence of the blocking phenomenon can be suppressed. Further, according to the method of manufacturing a thermal head of the present invention, a thermal head in which the occurrence of the sticking phenomenon is suppressed can be manufactured.

Drawings

Fig. 1 is a plan view showing a thermal head according to a first embodiment.

Fig. 2 is a sectional view taken along line II-II of fig. 1.

Fig. 3 is a plan view of a main portion of fig. 1 with a part enlarged.

Fig. 4 is a plan view of a main portion of fig. 3 with the protective layer omitted.

Fig. 5 is a sectional view of a main portion along the line V-V of fig. 3.

Fig. 6 is a sectional view of an essential part along the line VI-VI of fig. 3.

Fig. 7 is a flowchart showing an example of the method for manufacturing the thermal head according to the first embodiment.

Fig. 8 is a plan view showing a step of the method of manufacturing the thermal head according to the first embodiment.

Fig. 9 is a plan view showing a step of the method of manufacturing the thermal head according to the first embodiment.

Fig. 10 is a plan view showing a step of the method of manufacturing the thermal head according to the first embodiment.

Fig. 11 is a plan view showing a step of the method of manufacturing the thermal head according to the first embodiment.

Fig. 12 is a plan view of a principal part showing a step of the method of manufacturing the thermal head according to the first embodiment.

Fig. 13 is a sectional view of a main part showing a step of the method of manufacturing the thermal head according to the first embodiment.

Fig. 14 is a plan view of a principal part showing a step of the method of manufacturing the thermal head according to the first embodiment.

Fig. 15 is a sectional view of a principal part showing a step of the method of manufacturing the thermal head according to the first embodiment.

Fig. 16 is a plan view of a principal part showing a step of the method of manufacturing the thermal head according to the first embodiment.

Fig. 17 is a sectional view of a principal part showing a step of the method of manufacturing the thermal head according to the first embodiment.

Fig. 18 is a plan view of a principal part showing a step of the method of manufacturing the thermal head according to the first embodiment.

Fig. 19 is a sectional view of a main portion of a thermal head showing a modification of the first embodiment.

Fig. 20 is a plan view of a main portion of a thermal head according to a second embodiment.

Fig. 21 is a plan view of a main portion of fig. 20 with the protective layer omitted.

Fig. 22 is a sectional view taken along line XXII-XXII of fig. 21.

Fig. 23 is a sectional view taken along line XXIII-XXIII of fig. 21.

Fig. 24 is a flowchart showing an example of a method for manufacturing a thermal head according to a second embodiment.

Fig. 25 is a sectional view of a principal part showing a step of the method of manufacturing the thermal head according to the second embodiment.

Fig. 26 is a plan view of a principal part showing a step of the method of manufacturing the thermal head according to the second embodiment.

Fig. 27 is a plan view of a principal part showing a step of the method of manufacturing the thermal head according to the second embodiment.

Fig. 28 is a plan view of a principal part showing a step of the method of manufacturing the thermal head according to the second embodiment.

Fig. 29 is a sectional view of a principal part showing a step of the method of manufacturing the thermal head according to the second embodiment.

Fig. 30 is a plan view of a principal part showing a step of a method of manufacturing a thermal head according to a second embodiment.

Fig. 31 is a plan view of a principal part showing a step of the method of manufacturing the thermal head according to the second embodiment.

Fig. 32 is a sectional view of a principal part showing a step of the method of manufacturing the thermal head according to the second embodiment.

Fig. 33 is a plan view of a principal part showing a step of the method of manufacturing the thermal head according to the second embodiment.

Fig. 34 is a plan view of a main portion of a thermal head according to a modification (first modification) of the second embodiment.

Fig. 35 is a sectional view of a main portion of a thermal head according to another modification (second modification) of the second embodiment.

Fig. 36 is a flowchart showing an example of a method for manufacturing a thermal head according to another modification (second modification) of the second embodiment.

Fig. 37 is a sectional view of a main portion of a thermal head according to another modification (third modification) of the second embodiment.

Fig. 38 is a flowchart showing an example of a method for manufacturing a thermal head according to another modification (third modification) of the second embodiment.

Fig. 39 is a plan view showing a thermal head according to a third embodiment.

Fig. 40 is a plan view of a main part of fig. 39 with a part thereof enlarged.

FIG. 41 is a sectional view along the XLI-XLI line of FIG. 40.

FIG. 42 is a cross-sectional view along line XLII-XLII of FIG. 40.

Fig. 43 is a flowchart showing an example of the method for manufacturing the thermal head according to the third embodiment.

Fig. 44 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a third embodiment.

Fig. 45 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a third embodiment.

Fig. 46 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a third embodiment.

Fig. 47 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a third embodiment.

Fig. 48 is a sectional view of a principal part showing a step of the method of manufacturing the thermal head according to the third embodiment.

Fig. 49 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a third embodiment.

Fig. 50 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a third embodiment.

Fig. 51 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a third embodiment.

Fig. 52 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a third embodiment.

Fig. 53 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a third embodiment.

Fig. 54 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a third embodiment.

Fig. 55 is a sectional view of a main part showing a step of the method of manufacturing the thermal head according to the third embodiment.

Fig. 56 is a plan view of a main portion of a thermal head according to a fourth embodiment.

Fig. 57 is a sectional view of a substantial portion thereof taken along line LVII-LVII of fig. 56.

Fig. 58 is a sectional view of a principal portion thereof taken along the line LVIII-LVIII of fig. 56.

Fig. 59 is a flowchart showing a method of manufacturing a thermal head according to a fourth embodiment.

Fig. 60 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a fourth embodiment.

Fig. 61 is a sectional view of a main part showing a step of a method of manufacturing a thermal head according to a fourth embodiment.

Fig. 62 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a fourth embodiment.

Fig. 63 is a sectional view of a main part showing a step of a method of manufacturing a thermal head according to a fourth embodiment.

Fig. 64 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a fourth embodiment.

Fig. 65 is a sectional view of a main part showing a step of a method of manufacturing a thermal head according to a fourth embodiment.

Fig. 66 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a fourth embodiment.

Fig. 67 is a sectional view of a main part showing a step of a method of manufacturing a thermal head according to a fourth embodiment.

Fig. 68 is a plan view of a principal part showing a thermal head according to a fifth embodiment.

Fig. 69 is a sectional view of an essential part along the line LXIX-LXIX of fig. 68.

Fig. 70 is a flowchart showing a method of manufacturing a thermal head according to a fifth embodiment.

Fig. 71 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to a fifth embodiment.

Fig. 72 is a sectional view of a principal part showing one step of a method of manufacturing a thermal head according to a fifth embodiment.

Fig. 73 is a sectional view of a main portion of a thermal head according to a modification (first modification) of the fifth embodiment.

Fig. 74 is a flowchart showing a method of manufacturing a thermal head according to a modification (first modification) of the fifth embodiment.

Fig. 75 is a plan view of a main portion of a thermal head showing another configuration of a modification (first modification) of the fifth embodiment.

Fig. 76 is a plan view of a main portion of a thermal head according to another modification (second modification) of the fifth embodiment.

Fig. 77 is a plan view of a main portion of a thermal head according to another modification (second modification) of the fifth embodiment.

FIG. 78 is a sectional view of a main portion of the LXXVIII-LXXVIII line in FIG. 76.

Fig. 79 is a flowchart showing a method of manufacturing a thermal head according to another modification (second modification) of the fifth embodiment.

Description of reference numerals

A1, A2, B1-B4, C1, D1, E1-E3: thermal print head

1: head substrate

10. 10K: base material

11. 11K: major face

12. 12K: back side of the panel

13. 13K: convex part

130. 130K: top part

131A, 131B: first inclined part

132A, 132B: second inclined part

132K: inclined part

14: glaze layer

141: concave part

15: local glaze

150: glass paste

151: separation part

16: whole surface glaze

19: insulating layer

191: second region

192: second concave part

193: second convex part

2: protective layer

2 a: concave part

201: first layer

202: second layer

203: third layer

21: first region

22: first concave part

23: first convex part

29: trough

3: electrode layer

3K: wiring film

30: conductive paste

301: first conductor layer

301K: a first conductive film

302: second conductor layer

302K: second conductive film

303: seed layer

304: coating layer

31: common electrode

311: band-shaped part

312: connecting part

312 a: ag layer

313: straight part

314: branching part

315: band-shaped part

316: connecting part

32: independent electrode

321: band-shaped part

322: bonding part

323: connecting part

323 a: parallel portion

323 b: deflection part

33: relay electrode

331: band-shaped part

332: connecting part

4: resistor layer

4K: resistor film

41: heating part

5: connection substrate

51: major face

52: back side of the panel

59: connector with a locking member

61. 62: conducting wire

7: driver IC

78: protective resin

8: heat dissipation component

81: bearing surface

G1: paper pressing roller

Pr: thermal printer

P1: printing medium

Detailed Description

Preferred embodiments of the thermal head according to the present invention will be described below with reference to the drawings. Hereinafter, the same or similar components are denoted by the same reference numerals, and redundant description thereof will be omitted.

In the present invention, "something a is formed on something B" and "something a is formed on (on) something B" include "something a is formed directly on something B" and "something is present between something a and something B and something a is formed on something B" unless otherwise specified. Similarly, "something a is disposed on something B" and "something a is disposed on (over) something B" include "something a is disposed directly on something B" and "something is present between something a and something B and something a is disposed on something B" unless otherwise specified. As such. "something a is located on (over) something B", unless otherwise stated, includes "something a is in contact with something B and something a is located on something B" and "something is present between something a and something B and something a is located on something B". Likewise, "something a is laminated on something B" and "something a is laminated on (on) something B" include "something a is directly laminated on something B" and "something is present between something a and something B, and something a is laminated on something B" unless otherwise specified. In addition, "something a overlaps something B in a certain direction" includes "something a overlaps something B entirely" and "something a overlaps something B partially" unless otherwise stated.

[ first embodiment ]

Fig. 1 to 6 show a thermal head a1 according to a first embodiment. The thermal head a1 includes a head substrate 1, a protective layer 2, an electrode layer 3, a resistor layer 4, a connection substrate 5, a plurality of

lead wires

61, 62, a plurality of driver ICs 7, a protective resin 78, and a heat dissipation member 8.

The thermal head a1 is incorporated in a thermal printer Pr (see fig. 2) that prints on a print medium P1. The thermal printer Pr includes a thermal head a1 and a platen roller G1. The platen roller G1 faces the thermal head a 1. The print medium P1 is sandwiched between the thermal head a1 and the platen roller G1, and is conveyed in the sub-scanning direction by the platen roller G1. As such a printing medium P1, for example, a thermal paper used for producing barcode paper or receipts can be given. In the thermal head a1, a plurality of heat generating portions 41 are formed on the resistor layer 4, and printing is performed on the printing medium P1 by selectively driving the plurality of heat generating portions 41 to generate heat. Instead of the platen roller G1, a flat platen made of rubber may be used. The platen includes a portion of cylindrical rubber having a large radius of curvature, which has a bow-like shape in cross section. In the present invention, the term "platen" includes both the platen roller G1 and a flat platen. The thermal printer Pr is not limited to a printer that directly prints on thermal paper, and may be a thermal transfer type printer that selectively applies heat to an ink ribbon and prints on a print medium.

Fig. 1 is a plan view showing a thermal head a 1. In fig. 1, a first region 21 (two-dot chain line) to be described later in the protective layer 2 is shown by a phantom line, and the other part of the protective layer 2 is omitted. Fig. 2 is a sectional view taken along line II-II of fig. 1. Fig. 3 is a plan view of a main portion of fig. 1 with a part enlarged. Fig. 4 is a plan view of a main portion of fig. 3, with the protective layer 2 omitted. In fig. 4, a first region 21 described later is shown by a phantom line. Fig. 5 is a sectional view of a main portion along the line V-V of fig. 3. Fig. 6 is a sectional view of an essential part along the line VI-VI of fig. 3. In these figures, the thickness direction of the head substrate 1 is represented by z, the main scanning direction is represented by x, and the sub-scanning direction is represented by y. The thickness direction z, the main scanning direction x, and the sub-scanning direction y are orthogonal to each other. At the time of printing, the print medium P1 is conveyed in the direction indicated by the arrow in the sub scanning direction y (see fig. 2). In the sub-scanning direction y, the direction indicated by an arrow in the figure is set to be downstream, and the opposite direction is set to be upstream. In the thickness direction z, the direction indicated by the arrow in the figure is upward, and the opposite direction is downward.

As shown in fig. 1, the head substrate 1 has a plate shape extending long in the main scanning direction x. The head substrate 1 is a support member for the protective layer 2, the electrode layer 3, the resistor layer 4, and the plurality of driver ICs 7. The head substrate 1 has a base material 10 and a glaze layer 14.

The substrate 10 is made of, for example, AlN (aluminum nitride) or Al ₂ O ₃ Ceramics such as (alumina) and zirconia. The thickness of the substrate 10 is, for example, 0.6mm to 1.0 mm. As shown in fig. 1, the base material 10 is formed in a rectangular shape extending long in the main scanning direction x when viewed in the thickness direction z. As shown in fig. 5 and 6, the substrate 10 has a main surface 11 and a back surface 12. The main surface 11 and the back surface 12 are separated in the thickness direction z. The main surface 11 is the upper surface of the substrate 10 and faces upward in the thickness direction z. The back surface 12 is a lower surface of the base material 10 and faces downward in the thickness direction z.

Glaze layer 14 is formed on substrate 10 as shown in fig. 5 and 6. Glaze layer 14 covers at least a portion of main surface 11. The glaze layer 14 is made of a glass material such as amorphous glass. Glaze layer 14 includes a partial glaze 15 and a full-face glaze 16. The glaze layer 14 may be composed of only the partial glaze 15 without including the entire glaze 16.

The partial glaze 15 is formed on the main surface 11. The partial glaze 15 bulges in the thickness direction z when viewed in the main scanning direction x. The partial glaze 15 includes a plurality of separated portions 151.

The plurality of separating portions 151 are spaced apart from each other. As shown in fig. 5, each separating portion 151 has a cross section formed by a plane (y-z plane) orthogonal to the main scanning direction x and having an arc-shaped end edge. Each of the separating portions 151 is a belt-like shape extending in the sub-scanning direction y when viewed in the thickness direction z. The plurality of separating portions 151 are arranged along the main scanning direction x and are arranged parallel to each other.

As shown in fig. 5 and 6, the over glaze 16 covers the partial glaze 15 and also covers the main surface 11 exposed from the partial glaze 15. The cover glaze 16 is provided to cover the main surface 11 which is relatively rough, and to form a smooth surface suitable for forming the electrode layer 3. In the example shown in fig. 4 and 5, the entire glaze 16 covers the partial glaze 15, but the partial glaze 15 may not be covered, and only the main surface 11 exposed from the partial glaze 15 may be covered. The thickness of the entire glaze 16 is, for example, about 2.0 μm.

In the glaze layer 14, the partial glaze 15 is made of a glass material having a softening point of, for example, 800 ℃ to 850 ℃, and the entire glaze 16 is made of a glass material having a softening point of, for example, about 680 ℃. That is, the glass material forming the overglaze 16 has a lower softening point than the glass material forming the partial glaze 15. The material of the full-surface glaze 16 is preferably a glass paste having a lower viscosity than the glass paste used as the material of the partial glaze 15.

The electrode layer 3 constitutes a conduction path for conducting electricity to the resistor layer 4. The electrode layer 3 is formed of a conductive material. The conductive material is, for example, a metal such as Au (gold), Ag (silver), Cu (copper), or an alloy containing any of these metals. The electrode layer 3 is formed on the glaze layer 14 of the substrate 10. The thickness t1 (see fig. 6) of the electrode layer 3 is, for example, about 0.6 μm. The thickness t1 is a dimension along the thickness direction z. The electrode layer 3 has a common electrode 31 and a plurality of individual electrodes 32. The shape and arrangement of each part of the electrode layer 3 are not limited to the example shown in fig. 4, and various configurations can be formed. The material of each portion of the electrode layer 3 is not limited.

As shown in fig. 4, the common electrode 31 includes a plurality of strip portions 311 and a coupling portion 312. The coupling portion 312 is disposed at an edge of the head substrate 1 on the downstream side in the sub-scanning direction y, and is in a band shape extending in the main scanning direction x. The plurality of belt-like portions 311 extend from the coupling portion 312 in the sub-scanning direction y, and are arranged at equal intervals along the main scanning direction x. The arrangement pitch of the plurality of strip portions 311 in the main scanning direction x is, for example, 42.3 μm or more and 84.6 μm or less. The leading end (upstream side end in the sub-scanning direction y) of each belt-like portion 311 is positioned on each separating portion 151. Each strip portion 311 overlaps the resistor layer 4 when viewed in the thickness direction z.

In the example shown in fig. 4 and 5, the Ag layer 312a is laminated on the connection portion 312, but the Ag layer 312a may not be formed. The Ag layer 312a reduces the resistance of the connection portion 312. The Ag layer 312a is formed by, for example, printing and firing a paste containing an organic Ag compound, or a paste containing Ag particles, glass frit, palladium, and resin.

The individual electrodes 32 are members for locally applying current to the resistor layer 4. Each individual electrode 32 has a reverse polarity with respect to the common electrode 31. Each individual electrode 32 extends from the resistor layer 4 toward the driver IC 7. The plurality of individual electrodes 32 are arranged along the main scanning direction x. Each of the individual electrodes 32 includes a strip portion 321, a bonding portion 322, and a connecting portion 323.

As shown in fig. 4, the strip-shaped portion 321 extends in the sub-scanning direction y and is strip-shaped when viewed in the thickness direction z. Each strip 321 is disposed between 2 adjacent strips 321 of the common electrode 31. The arrangement pitch of the plurality of strip-shaped portions 321 in the main scanning direction x is, for example, 42.3 μm or more and 84.6 μm or less. The leading end (downstream side end in the sub-scanning direction y) of each belt-like portion 321 is positioned on each separating portion 151. Each strip 321 overlaps the resistor layer 4 when viewed in the thickness direction z. Each of the belt-shaped portions 321 has a portion overlapping each of the belt-shaped portions 311 when viewed in the main scanning direction x. Which is located on each of the separating portions 151.

As shown in fig. 4, the bonding portion 322 is formed at the end portion of each individual electrode 32 on the upstream side in the sub-scanning direction y. Each wire 61 is bonded to each bonding portion 322. Thereby, the individual electrodes 32 and the driver IC7 are electrically connected through the wires 61. The bonding portion 322 is exposed from the protective layer 2 as shown in fig. 3.

The coupling portion 323 is connected to the band portion 321 and the bonding portion 322 as shown in fig. 4. The coupling portion 323 extends from the belt-like portion 321 toward the upstream side in the sub-scanning direction y. As shown in fig. 4, the coupling portion 323 includes a parallel portion 323a and a skew portion 323 b. The parallel portion 323a has one end adjacent to the bonding portion 322 and extends in the sub-scanning direction y. The deflecting portion 323b is inclined with respect to the sub-scanning direction y. The deflecting portion 323b is sandwiched between the parallel portion 323a and the belt-like portion 321 in the sub-scanning direction y.

The resistor layer 4 is made of a material having a resistivity higher than that of the material constituting the electrode layer 3. The resistor layer 4 is made of, for example, ruthenium oxide. The resistor layer 4 is formed on the partial glaze 15 as shown in fig. 4. As shown in fig. 1, 3, and 4, the resistor layer 4 is in the form of a strip extending in the main scanning direction x when viewed in the thickness direction z. The resistor layer 4 intersects each of the strip portions 311 (common electrode 31) and each of the strip portions 321 (individual electrodes 32) when viewed in the thickness direction z. Further, the resistor layer 4 is formed across the plurality of separation portions 151 when viewed in the thickness direction z. The resistor layer 4 is laminated on the opposite side of the substrate 10 with respect to the

strip portions

311 and 321 in the thickness direction z. The thickness of the resistor layer 4 is, for example, 3 μm or more and 6 μm or less. Thus, the thickness of the resistor layer 4 is larger than the thickness t1 of the electrode layer 3. The material and thickness of the resistor layer 4 are not limited.

The resistor layer 4 has a plurality of heat generating portions 41. Each heat generating portion 41 is a portion of the resistor layer 4 sandwiched between each band-shaped portion 311 and each band-shaped portion 321. Each heat generating portion 41 generates heat by being locally energized through the electrode layer 3. The printed dots are formed by heat generated by the heat generating portions 41. The plurality of heat generating portions 41 are arranged along the main scanning direction x. The dot density of the thermal head a1 becomes higher as the number of heat generating portions 41 arranged in the main scanning direction x is larger in a unit length (for example, 1mm) of the substrate 10 in the main scanning direction x. In the present embodiment, each heat generating portion 41 overlaps between 2 separated portions 151 adjacent to each other in the main scanning direction x, as viewed in the thickness direction z.

The protective layer 2 is configured to protect the electrode layer 3, the resistor layer 4, and the like. However, the protective layer 2 exposes the bonding portions 322 of the individual electrodes 32. Security deviceThe protective layer 2 is made of, for example, amorphous glass. The protective layer 2 may have a structure in which a lower layer made of amorphous glass and an upper layer made of SiAlON or SiC (silicon carbide) are stacked, instead of amorphous glass. SiAlON is in silicon nitride (Si) ₃ N ₄ ) Medium synthetic alumina (Al) ₂ O ₃ ) And silicon oxide (SiO) ₂ ) The obtained silicon nitride engineering ceramics. The upper layer is formed, for example, by sputtering.

The protective layer 2 has a first region 21. As shown in fig. 1, the first region 21 is a band-shaped region extending along the main scanning direction x when viewed in the thickness direction z. The first region 21 overlaps the plurality of heat generation portions 41 (resistor layers 4) when viewed in the thickness direction z. The first region 21 is to transfer heat from the plurality of heat generating portions 41. The first region 21 overlaps the plurality of separated portions 151 (partial glaze 15) when viewed in the thickness direction z. The first region 21 includes a region of the protective layer 2 in which the print medium P1 is pressed by the platen roller G1 when printing is performed on the print medium P1. In the example shown in fig. 3, both ends of the first region 21 in the sub-scanning direction y overlap the separating portions 151 as viewed in the thickness direction z. The first region 21 includes a plurality of first recesses 22 and a plurality of first protrusions 23, as shown in fig. 6. Fig. 6 is a cross section in the first region 21.

The plurality of first concave portions 22 and the plurality of first convex portions 23 are alternately arranged along the main scanning direction x. The height difference d1 between each first concave portion 22 and each first convex portion 23 along the thickness direction z is larger than the thickness t1 of the electrode layer 3. The height difference d1 is a distance along the thickness direction z from the top of each first convex portion 23 to the bottom of each first concave portion 22.

As shown in fig. 6, each of the first recesses 22 is located above each of the heat generating portions 41. As understood from fig. 6, each first recess 22 overlaps each heat generation portion 41 as viewed in the thickness direction z. Each of the plurality of first concave portions 22 is located between 2 separated portions 151 adjacent to each other in the main scanning direction x when viewed in the thickness direction z. In the example shown in fig. 6, each first concave portion 22 may have a downwardly curved shape in a cross section formed on the basis of a plane (x-z plane) orthogonal to the sub-scanning direction y, and may have a flat bottom portion.

The plurality of first protrusions 23 overlap each of the separating portions 151 when viewed in the thickness direction z. In the example shown in fig. 6, each first convex portion 23 is flat in a cross section formed based on the x-z plane, but may be curved upward. In the example shown in fig. 5, each first convex portion 23 is curved upward along each separation portion 151 in a cross section formed on the y-z plane. As understood from fig. 6, each of the first protrusions 23 overlaps with each of the band-shaped

portions

311 or 321 as viewed in the thickness direction z.

In the first region 21, the portions of the protective layer 2 that overlap the respective separation portions 151 are the first convex portions 23 that rise upward, and the portions that do not overlap the separation portions 151 are the first concave portions 22, as viewed in the thickness direction z.

As shown in fig. 1 and 2, the connection substrate 5 is disposed upstream of the head substrate 1 in the sub-scanning direction y. The connection substrate 5 is, for example, a printed substrate, and is formed with a wiring pattern, not shown. A connector 59 described later is mounted on the connection substrate 5. The shape of the connection substrate 5 is not particularly limited, and in the present embodiment, it is a rectangular shape whose longitudinal direction is the main scanning direction x. The connection substrate 5 has a main surface 51 and a back surface 52. The main surface 51 and the back surface 52 are separated in the thickness direction z. The main surface 51 is the upper surface of the connection substrate 5 and faces the same direction as the main surface 11. The back surface 52 is a lower surface of the connection substrate 5 and faces the same direction as the back surface 12.

Each of the driver ICs 7 is mounted on the head substrate 1, for example, and is a component for independently energizing the plurality of heat generating portions 41. The driver ICs 7 may be mounted across the head board 1 and the connection board 5, or may be mounted on the connection board 5. As will be understood from fig. 2 to 4, the driver ICs 7 are connected to the individual electrodes 32 (the bonding portions 322) via the wires 61. The control of the energization of the plurality of heat generating portions 41 by the plurality of driver ICs 7 is performed in accordance with a command signal input from the outside of the thermal head a1 via the connection board 5. As shown in fig. 2, the driver ICs 7 are connected to a wiring pattern (not shown) of the connection substrate 5 via a plurality of leads 62. The plurality of driver ICs 7 are appropriately set in accordance with the number of the plurality of heat generating portions 41.

As understood from fig. 1 and 2, the plurality of driver ICs 7, the plurality of wires 61, and the plurality of wires 62 are covered with the protective resin 78. The protective resin 78 is made of, for example, an insulating resin, and is, for example, black. As shown in fig. 1 and 2, the protective resin 78 is formed so as to straddle the head substrate 1 and the connection substrate 5.

The connector 59 is used to connect the thermal head a1 to the thermal printer Pr. The connector 59 is mounted on the connection substrate 5 and connected to a wiring pattern (not shown) of the connection substrate 5.

As shown in fig. 2, the heat dissipation member 8 supports the head substrate 1 and the connection substrate 5. The heat dissipation member 8 is a member for dissipating part of the heat generated by the plurality of heat generation portions 41 to the outside via the head substrate 1. The heat dissipation member 8 is a block-shaped member made of metal such as aluminum, for example. The heat dissipation member 8 has a support surface 81 as shown in fig. 2. The support surface 81 faces upward in the thickness direction z. The back surface 12 of the base material 10 and the back surface 52 of the connection substrate 5 are bonded to the support surface 81.

Next, an example of a method for manufacturing the thermal head a1 will be described below with reference to fig. 7 to 18.

Fig. 7 is a flowchart showing an example of a method of manufacturing the thermal head a 1. Fig. 8, 9, and 11 are plan views showing a step of a method of manufacturing the thermal head a 1. Fig. 12, 14, 16, and 18 are plan views of essential parts showing a step of a method of manufacturing the thermal head a1, and correspond to the plan view of essential parts in fig. 3. Fig. 10, 13, 15, and 17 are sectional views of principal parts showing one step of a method of manufacturing the thermal head a1, and correspond to the sectional view of the principal part of fig. 6.

As shown in fig. 7, the method of manufacturing the thermal head a1 includes a base material preparation step S11, a glaze formation step S12, an electrode layer formation step S13, a resistor layer formation step S14, a protective layer formation step S15, a singulation step S161, and an assembly step S162.

[ substrate preparation Process S11 ]

First, the substrate 10 is prepared. The prepared substrate 10 is a ceramic plate, and AlN or Al is used as the ceramic ₂ O ₃ Zirconium oxide, and the like. The prepared base material 10 is, for example, of a size that enables a plurality of head substrates 1 to be manufactured. As described above, the substrate 10 has the main surface 11 and the back surface 12.

[ glaze formation Process S12 ]

Next, the glaze layer 14 is formed on the main surface 11 of the substrate 10. As shown in fig. 7, in the glaze forming step S12, the partial glaze forming process S121, the partial glaze dividing process S122, and the full-surface glaze forming process S123 are performed in this order.

In the partial glaze forming process S121, as shown in fig. 8, the glass paste 150 is thick-film printed on the main surface 11 and dried. The formed glass paste 150 has a rectangular shape extending in the main scanning direction x, as shown in fig. 7.

In the partial glaze dividing process S122, as shown in fig. 9 and 10, the dried glass paste 150 is divided into a plurality of separating portions 151. The division into the plurality of separation portions 151 is performed by etching using an etching solution such as hydrogen fluoride. The division may be performed by laser processing without etching. Thereafter, the plurality of separated portions 151 are fired, thereby forming the partial glaze 15 including the plurality of separated portions 151.

In the full-surface glaze forming process S123, as shown in fig. 11, a glass paste is thick-film printed on substantially the entire main surface 11 and fired. Thereby, the full-surface glaze 16 is formed. That is, the head substrate 1 having the base material 10 and the glaze layer 14 is formed. The full-surface glaze 16 is formed so as to cover the partial glaze 15 (the plurality of separation portions 151) and also cover the main surface 11 exposed from the partial glaze 15. The whole glaze 16 protrudes upward from the portion covering the main surface 11, covering the partial glaze 15.

[ electrode layer Forming Process S13 ]

Next, electrode layer 3 is formed on glaze layer 14. In the electrode layer forming step S13, the conductive paste application process, the conductive paste firing process, and the conductive film patterning process are sequentially performed.

In the conductive paste application process, as shown in fig. 12 and 13, a conductive paste 30 is applied on the glaze layer 14 by thick film printing, for example. As the conductive paste 30, for example, a resin acid Au paste material is used. The resin acid Au paste contains Au as a metal component, and rhodium, vanadium, bismuth, silicon, and the like are added as additive elements, for example. The metal component is not limited to Au, and may be Ag, Cu, or the like.

In the conductive paste firing process, the conductive paste 30 is fired, and a conductive film is formed. The conductive film contains Au as a metal component and is formed as a film covering the region coated with the conductive paste 30 shown in fig. 12 and 13.

In the conductive film patterning process, patterning is performed on the conductive film. In the patterning, for example, a photosensitive resist film is formed on the conductive film, and the resist film is patterned by photolithography. Next, the conductive film is etched using the resist film as a mask. This results in the electrode layer 3 shown in fig. 14 and 15. The Ag layer 312a may be formed by, for example, patterning a conductive film, thick-film printing a paste containing Ag on the connection portion 312 of the common electrode 31, and then firing the paste.

Unlike the present embodiment, photosensitive paste may be used as the conductive paste 30. In this case, a patterning process can be performed by performing a photosensitive process using photolithography or the like on the conductive paste 30.

[ resistor layer Forming Process S14 ]

Next, the resistor layer 4 is formed. In the resistor layer forming step S14, a resistor paste application process and a resistor paste firing process are sequentially performed.

In the resistor paste application process, a resistor paste containing ruthenium oxide is applied to the glaze layer 14 by thick film printing or the like. At this time, the resistor paste is applied in a band shape extending in the main scanning direction x, and is applied on the glaze layer 14 so that the plurality of band-shaped portions 311 and the plurality of band-shaped portions 321 intersect each other. Further, the resistor paste is applied so as to extend over the plurality of separation portions 151 when viewed in the thickness direction z.

The resistor paste is fired in a resistor paste firing process. Thereby, the resistor layer 4 shown in fig. 16 and 17 is formed. As shown in fig. 17, the resistor layer 4 is formed such that the portion formed on the isolation portion 151 bulges upward than the portion not formed on the isolation portion 151. That is, the resistor layer 4 has irregularities in the thickness direction z.

[ protective layer Forming Process S15 ]

Then, the protective layer 2 is formed. In the protective layer forming step S15, for example, after the resistor layer forming step S14, a glass paste constituting the protective layer 2 is thick-film printed on the glaze layer 14, the electrode layer 3, and the resistor layer 4 exposed to the outside. Then, the glass paste with the thick film printed thereon is fired. Thereby, the protective layer 2 shown in fig. 18 is formed. On the surface of the formed protective layer 2, irregularities are formed along the irregularities in the thickness direction z of the resistor layer 4. That is, the protective layer 2 forms the first region 21 having the plurality of first concave portions 22 and the plurality of first convex portions 23. The plurality of first concave portions 22 and the plurality of first convex portions 23 are alternately arranged along the main scanning direction x.

[ singulation step S161 ]

Next, the base material 10 is appropriately divided for each head substrate 1. In the base material preparation step S11, when the base materials 10 corresponding to 1 head substrate 1 are prepared, the singulation step S161 may not be performed. The singulation step S161 can select laser cutting, dicing, or the like, for example, depending on the material of the substrate 10.

[ Assembly step S162 ]

Thereafter, the head substrate 1 and the connection substrate 5 are mounted on the heat dissipation member 8, the driver IC7 is mounted, the plurality of wires 61 and the plurality of wires 62 are bonded, and the protective resin 78 is formed. The thermal head a1 shown in fig. 1 to 6 was produced through the steps shown in fig. 6.

The method of manufacturing the thermal head a1 described above is an example, and can be modified as appropriate. For example, in the glaze forming step S12, the partial glaze forming process S121, the partial glaze dividing process S122, and the full-surface glaze forming process S123 are performed in this order. The whole glaze forming process S123, the partial glaze forming process S121, and the partial glaze dividing process S122 may be performed in this order. In this case, the entire surface of the main surface 11 of the substrate 10 is covered with the entire surface glaze 16, and the partial glaze 15 (each of the separation portions 151) is formed on the entire surface glaze 16.

The function and effect of the thermal head a1 are as follows.

In the thermal head a1, the protective layer 2 has a first region 21, and the first region 21 has a plurality of first concave portions 22 and a plurality of first convex portions 23. The plurality of first concave portions 22 and the plurality of first convex portions 23 are alternately arranged along the main scanning direction x. According to this structure, the surface in the first region 21 of the protective layer 2 undulates along the main scanning direction x. Therefore, when the print medium P1 is pressed against the thermal head a1 by the platen roller G1 at the time of printing, the print medium P1 contacts the plurality of first convex portions 23 and does not contact the plurality of first concave portions 22. Therefore, a slight gap can be locally generated between the printing medium P1 and the protective layer 2, and therefore the sticking of the printing medium P1 to the thermal head a1 can be suppressed. That is, the thermal head a1 can suppress the occurrence of the blocking phenomenon.

In the thermal head a1, the height difference d1 along the thickness direction z between each of the plurality of first concave portions 22 and each of the plurality of first convex portions 23 is larger than the thickness t1 along the thickness direction z of the electrode layer 3. In a thermal head different from the thermal head a1, in a structure in which the partial glaze 15 is not divided into the plurality of separation portions 151, a difference in level may occur between a portion where the resistor layer 4 is formed on the electrode layer 3 and a portion where the resistor layer 3 is not formed (a portion formed on the glaze layer 14). However, the height difference is about the thickness t1 of the electrode layer 3, and due to the unevenness of the surface of the protective layer 2 caused by the height difference, a proper gap may not be secured while suppressing the blocking phenomenon. On the other hand, in the thermal head a1, the height difference d1 is larger than the thickness t1 of the electrode layer 3. Therefore, the thermal head a1 can appropriately secure a local gap between the print medium P1 and the protective layer 2 while suppressing the blocking phenomenon.

In the thermal head a1, the partial glaze 15 is divided into a plurality of separation sections 151. According to this structure, a level difference is generated by the presence or absence of each separation portion 151, and irregularities in the thickness direction z are formed in the resistor layer 4 formed on each separation portion 151 (partial glaze 15). Then, irregularities (a plurality of first concave portions 22 and a plurality of first convex portions 23) are formed on the surface of the protective layer 2 along the irregularities of the resistor layer 4. That is, the height difference d1 between each first concave portion 22 and each first convex portion 23 in the first region 21 is set to a size corresponding to the thickness of the partial glaze 15 (each separation portion 151). The thickness of the partial glaze 15 (each of the separation portions 151) is larger than the thickness t1 of the electrode layer 3. Therefore, the thermal head a1 can form the step d1 larger than the thickness t1 of the electrode layer 3 on the surface of the protective layer 2 in the first region 21.

Fig. 19 shows a thermal head a2 according to a modification of the first embodiment. Fig. 19 is a sectional view of a principal part showing the thermal head a2, corresponding to the sectional view of the principal part of fig. 5.

In the thermal head a1, the

respective strip portions

311 and 321 are formed on the respective separating portions 151, respectively. On the other hand, in the thermal head a2, as shown in fig. 19, each of the

strip portions

311 and 321 is formed so as to pass between 2 separating portions 151 adjacent in the main scanning direction x.

As shown in fig. 19, in the thermal head a2, each first projection 23 overlaps each heat generating portion 41 as viewed in the thickness direction z. Each of the first convex portions 23 overlaps each of the separating portions 151 when viewed in the thickness direction z. Each first concave portion 22 overlaps with 2 heat generation portions 41 adjacent to each other in the main scanning direction x when viewed in the thickness direction z. Each first concave portion 22 overlaps each band-shaped portion 311 or each band-shaped portion 321.

The thermal head a2 can also exhibit the same effects as the thermal head a 1.

[ second embodiment ]

Fig. 20 to 23 show a thermal head B1 according to a second embodiment. In the thermal head a1, the partial glaze 15 is divided into the plurality of separation portions 151, whereby the plurality of first concave portions 22 and the plurality of first convex portions 23 are formed. On the other hand, the thermal head B1 does not divide the partial glaze 15 into the plurality of separation portions 151, and forms the plurality of first concave portions 22 and the plurality of first convex portions 23 by a configuration described in detail later.

Fig. 20 is a plan view showing a main part of the thermal head B1, corresponding to fig. 3. Fig. 21 is a plan view of a main portion of fig. 20, in which the protective layer 2 is omitted, and corresponds to fig. 4. Fig. 22 is a sectional view taken along line XXII-XXII of fig. 21. Fig. 23 is a sectional view taken along line XXIII-XXIII of fig. 21.

As described above, the partial glaze 15 is not divided into the plurality of separation portions 151. As can be understood from fig. 20 and 21, the partial glaze 15 is a band shape having a longitudinal direction in the main scanning direction x when viewed in the thickness direction z. The partial glaze 15 is understood from fig. 22 to be exposed from the full-face glaze 16. The entire glaze 16 is formed to a different extent from the thermal head a 1. Unlike this structure, the entire glaze 16 may cover the entire upper surface of the partial glaze 15, similarly to the thermal head a 1. The glaze layer 14 may have a structure in which the entire main surface 11 of the substrate 10 is covered with the full-surface glaze 16 without the partial glaze 15.

The electrode layer 3 has the same portion as the electrode layer 3 of the thermal head a1, and the positional relationship between each strip-shaped portion 311 and each strip-shaped portion 321 is different from that of the electrode layer 3 of the thermal head a 1. As shown in fig. 21, the belt-shaped portions 321 are arranged at intervals in the sub-scanning direction y with respect to the belt-shaped portions 311. The belt-shaped portions 321 facing each other in the sub-scanning direction y are substantially at the same position as the belt-shaped portions 311 in the main scanning direction x.

As shown in fig. 21 and 23, the resistor layer 4 is divided into heat generating portions 41. The plurality of heat generating portions 41 overlap each of the

belt portions

311 and 321 facing each other in the sub-scanning direction y. That is, the dimension of each heat generating portion 41 in the sub-scanning direction y is larger than the distance between each belt portion 311 and each belt portion 321 in the sub-scanning direction y. The dimensions of the plurality of heat generating portions 41 in the sub-scanning direction y are substantially the same.

The protective layer 2 has a first layer 201, a second layer 202, and a third layer 203 as shown in fig. 22 and 23. The first layer 201 is, for example, an oxide film made of, for example, SiO ₂ And (4) forming. The second layer 202 is, for example, a protective film made of, for example, SiC. The third layer 203 is, for example, an oxide film made of, for example, SiO ₂ And (4) forming. In the example shown in fig. 22 and 23, the second layer 202 is thicker than each of the first layer 201 and the third layer 203.

Protective layer 2 as understood from fig. 20 and 23, the first layer 201 and the second layer 202 are partially removed. Thus, the protective layer 2 includes a portion in which the first layer 201, the second layer 202, and the third layer 203 are stacked in this order, and a portion constituted only by the third layer 203. For example, as shown in fig. 23, the heat generating portion 41 is a portion where a first layer 201, a second layer 202, and a third layer 203 are stacked. As shown in fig. 23, a portion composed only of the third layer 203 is formed between 2 heat generating portions 41 adjacent in the main scanning direction x.

As shown in fig. 20 and 23, the protective layer 2 of the thermal head B1 has the first region 21, similarly to the thermal head a 1. In the example shown in fig. 20, both ends of the first region 21 in the sub-scanning direction y overlap the heat generating portions 41 as viewed in the thickness direction z. In the first region 21, the plurality of first concave portions 22 and the plurality of first convex portions 23 are alternately arranged along the main scanning direction x. In the thermal head B1, the plurality of first recesses 22 overlap with the portion of the protective layer 2 that is not the first layer 201 and the second layer 202 but is constituted only by the third layer 203. The plurality of first projections 23 overlap with a portion of the protective layer 2 where the first layer 201, the second layer 202, and the third layer 203 are sequentially stacked. Each first convex portion 23 is located in a region of the first region 21 overlapping the heat generating portion 41 when viewed in the thickness direction z, and each first concave portion 22 is located in a region of the first region 21 not overlapping the heat generating portion 41 when viewed in the thickness direction z.

Next, an example of a method for manufacturing the thermal head B1 will be described below with reference to fig. 24 to 33.

Fig. 24 is a flowchart showing an example of a method of manufacturing the thermal head B1. Fig. 25 is a sectional view of a principal part showing a step of a method of manufacturing the thermal head B1, and corresponds to fig. 22. Fig. 26 to 28, 30, 31, and 33 are plan views of essential parts showing a step of a method of manufacturing the thermal head B1, and correspond to fig. 20. Fig. 29 and 32 are sectional views of essential parts showing a step of a method of manufacturing the thermal head B1, and correspond to fig. 23.

As shown in fig. 24, the method of manufacturing the thermal head B1 includes a base material preparation step S21, a glaze formation step S22, an electrode layer formation step S23, a resistor layer formation step S24, a protective layer primary formation step S25, a laser processing step S26, a protective layer secondary formation step S27, a singulation step S281, and an assembly step S282.

[ substrate preparation Process S21 ]

First, the substrate 10 is prepared. The substrate preparation step S21 is performed in the same manner as the substrate preparation step S11.

[ glaze formation Process S22 ]

Next, as shown in fig. 25, a glaze layer 14 is formed. In the glaze forming step S22, the partial glaze 15 is formed and then the full-surface glaze 16 is formed. The glaze forming step S22 is different from the glaze forming step S12 in that the partial glaze dividing process S122 is not performed. In the glaze forming step S22, the formation range of the entire glaze 16 is different from that in the glaze forming step S12.

[ electrode layer Forming Process S23 ]

Next, the electrode layer 3 is formed as shown in fig. 26. The electrode layer forming step S23 is performed in the same manner as the electrode layer forming step S13. The formation range of the electrode layer 3 is the same as that shown in fig. 21.

[ resistor layer Forming Process S24 ]

Next, as shown in fig. 27, the resistor layer 4 is formed. The resistor layer forming step S24 is performed in the same manner as the resistor layer forming step S14. As can be understood from fig. 27, the formed resistor layer 4 is formed in a stripe shape in which the main scanning direction x is the longitudinal direction when viewed in the thickness direction z.

[ protective layer one-shot Forming Process S25 ]

Next, as shown in fig. 28 and 29, a first layer 201 and a second layer 202 among the protective layer 2 are formed. As shown in fig. 24, in the protective layer primary forming step S25, the oxide film forming process S251 and the protective film forming process S252 are sequentially formed.

In the oxide film forming process S251, an oxide film as the first layer 201 is formed on the entire upper surfaces of the glaze layer 14, the electrode layer 3, and the resistor layer 4 after the resistor layer forming step S24. The oxide film is formed by sputtering, for example. The oxide film formed is made of, for example, SiO ₂ And (4) forming. The first layer 201 may be formed by containing SiO (oxide film forming process S251) ₂ And printing and firing the structured glass paste.

In the protective film forming process S252, a protective film as the second layer 202 is formed on the first layer 201. The protective film is formed by, for example, sputtering or CVD. The formed protective film is made of, for example, SiC.

[ laser processing procedure S26 ]

Next, the resistor layer 4 is divided into the heat generating portions 41 by laser irradiation. In the laser processing step S26, for example, each of the plurality of regions R1 shown in fig. 30 is irradiated with laser light from the second layer 202. Each of the plurality of regions R1 is linear extending in the sub scanning direction y when viewed in the thickness direction z. Each of the regions R1 intersects the resistor layer 4. In each region R1 irradiated with the laser beam, the second layer 202, the first layer 201, and the resistor layer 4 are partially removed, and a plurality of grooves 29 are formed as shown in fig. 31 and 32. As shown in fig. 32, each of the plurality of grooves 29 extends from the second layer 202 to the resistor layer 4 in the thickness direction z. As shown in fig. 32, in each of the plurality of grooves 29, the second layer 202, the first layer 201, and the resistor layer 4 (each heat generating portion 41) are exposed, and the upper surface of the glaze layer 14 (partial glaze 15) is also exposed.

In the laser processing step S26, when dividing the resistor layer 4 into the heat generating portions 41, the grooves 29 may be irradiated with laser light until the grooves reach the glaze layer 14 (partial glaze 15). In this case, the laser may be irradiated to penetrate the glaze layer 14 in the thickness direction z, may be irradiated to a point in the thickness direction z of the glaze layer 14, or may be irradiated to a point where a trace of the laser irradiation is left in the glaze layer 14 (partial glaze 15).

[ Secondary Forming Process for protective layer S27 ]

Next, as shown in fig. 33, the third layer 203 in the protective layer 2 is formed. As shown in fig. 24, in the protective layer secondary forming step S27, an oxide film forming process S271 is performed.

In the oxide film forming process S271, an oxide film as the third layer 203 is formed on the second layer 202 after the laser processing step S26. The oxide film is formed by, for example, sputtering in the same manner as in the oxide film forming process S251, and the oxide film formed is, for example, SiO ₂ And (4) forming. Thereby, the protective layer 2 having the first layer 201, the second layer 202, and the third layer 203 is formed. The oxide film (third layer 203) thus formed enters each groove 29 formed in the laser processing step S26. Therefore, the surface of the third layer 203 (the surface of the protective layer 2) is in the region where the groove 29 existsIs recessed in the thickness direction z. That is, the protective layer 2 forms the first region 21 having the plurality of first concave portions 22 and the plurality of first convex portions 23. The plurality of first concave portions 22 and the plurality of first convex portions 23 are alternately arranged along the main scanning direction x. The oxide film (third layer 203) formed covers the side of the second layer 202, the side of the first layer 201, and the side of the resistor layer 4 (heat generating portions 41) exposed in the grooves 29 after the laser processing step S26, and also covers the upper surface of the glaze layer 14 (partial glaze 15) exposed in the grooves 29.

[ singulation step S281 ] [ Assembly step S282 ]

After that, the thermal head B1 shown in fig. 20 to 23 is manufactured through the singulation step S281 and the assembly step S282. The singulation step S281 is performed in the same manner as the singulation step S161, and the assembly step S282 is performed in the same manner as the assembly step S162.

The function and effect of the thermal head B1 are as follows.

Similarly to the thermal head a1, the thermal head B1 has a plurality of first concave portions 22 and a plurality of first convex portions 23 alternately arranged in the main scanning direction x formed in the first region 21 of the protective layer 2. Therefore, the thermal head B1 can suppress the occurrence of the blocking phenomenon as in the thermal head a 1.

In the thermal head B1, the height difference d1 in the thickness direction z between each of the plurality of first concave portions 22 and each of the plurality of first convex portions 23 is larger than the thickness t1 in the thickness direction z of the electrode layer 3, similarly to the thermal head a 1. Therefore, the thermal head B1 can suppress the blocking phenomenon and appropriately ensure a local gap between the print medium P1 and the protective layer 2, similarly to the thermal head a 1.

In the thermal head B1, the resistor layer 4 is divided into heat generating portions 41. With this configuration, a level difference is generated by the presence or absence of each heat generating portion 41 (resistor layer 4), and irregularities (the plurality of first concave portions 22 and the plurality of first convex portions 23) are formed on the surface of the protective layer 2 at least by the level difference. That is, the height difference d1 between each first concave portion 22 and each first convex portion 23 in the first region 21 is set to a size corresponding to the thickness of the resistor layer 4 (each heat generating portion 41). The thickness of the resistor layer 4 is larger than the thickness t1 of the electrode layer 3. Therefore, the thermal head B1 can form the level difference d1 larger than the thickness t1 of the electrode layer 3 on the surface of the protective layer 2 in the first region 21. In particular, in the thermal head B1, when the resistor layer 4 is divided into the heat generating portions 41, the first layer 201 and the second layer 202 of the protective layer 2 are partially removed (see the laser processing step S26). Therefore, since a step is further generated by the presence or absence of the first layer 201 and the second layer 202, the step d1 between each first concave portion 22 and each first convex portion 23 can be increased.

In the thermal head B1, the protective layer 2 has the third layer 203. In the method of manufacturing the thermal head B1, the laser processing step S26 is performed after the protective layer primary forming step S25. Therefore, after the laser processing step S26, the side of the resistor layer 4 (each heat generating portion 41) is exposed in each groove 29. In this way, if the heat generating portions 41 are partially exposed, there is a concern that unintended conduction may occur between the heat generating portions 41. Therefore, the protective layer secondary forming step S27 (oxide film forming process S271) is performed after the laser processing step S26, whereby the third layer 203 is formed and each heat generating portion 41 is covered with the protective layer 2. This can suppress unintended conduction of the heat generating portions 41 in the thermal head B1.

Fig. 34 shows a thermal head B2 according to a modification (first modification) of the second embodiment. Fig. 34 is a plan view showing a main part of the thermal head B2, corresponding to fig. 23.

Unlike the thermal head B1, the thermal head B2 does not divide the resistor layer 4 into a plurality of heat generating portions 41. The thermal head B2 is formed, for example, by leaving the second layer 202 and the first layer 201 to be partially removed without dividing the resistor layer 4 in the laser processing step S26. In the thermal head B2, since the resistor layer 4 is not divided into the plurality of heat generating portions 41, the

respective strip portions

311 and 321 are not separated in the sub-scanning direction y, but are arranged alternately in the main scanning direction x in the same manner as the thermal head a 1.

In the thermal head B2, the protective layer 2 has the first region 21, similarly to the thermal heads a1 and B1. The first region 21 has a plurality of first recesses 22 and a plurality of first projections 23 alternately arranged along the main scanning direction x. Therefore, the thermal head B2 can suppress the occurrence of the blocking phenomenon, similarly to the thermal heads a1 and B1. In addition, in the thermal head B2, as understood from fig. 34, a level difference d1 between each first concave portion 22 and each first convex portion 23 is generated in accordance with the thickness of the second layer 202. The thickness of the second layer 202 is greater than the thickness t1 of the electrode layer 3. Thus, the thermal head B2 can form the appropriate height difference d1 while suppressing the sticking phenomenon.

Fig. 35 and 36 show a thermal head B3 according to another modification (second modification) of the second embodiment. Fig. 35 is a sectional view of a main part of the thermal head B3, corresponding to fig. 23. Fig. 36 is a flowchart showing an example of a method of manufacturing the thermal head B3.

As shown in fig. 35, the thermal head B3 is configured such that the protective layer 2 does not have the third layer 203 and is composed of the first layer 201 and the second layer 202, as compared with the thermal head B1. The first layer 201 and the second layer 202 are not divided but connected in the first region 21 as shown in fig. 35.

In the thermal head B3, a difference in level occurs between the portion of the first region 21 where the heat generating portion 41 is disposed and the portion where the heat generating portion 41 is not disposed. The surface of the protective layer 2 (the surface of the second layer 202) is formed with irregularities due to the height difference. That is, a plurality of first concave portions 22 and a plurality of first convex portions 23 are formed in the first region 21 of the protective layer 2. As understood from fig. 35, the first convex portions 23 are located in the first region 21 in a region overlapping the heat generating portion 41 when viewed in the thickness direction z, and the first concave portions 22 are located in the first region 21 in a region not overlapping the heat generating portion 41 when viewed in the thickness direction z.

The thermal head B3 is formed by the process shown in fig. 36, for example. As shown in fig. 36, the method of manufacturing the thermal head B3 differs in the following respects as compared with the method of manufacturing the thermal head B1 (see fig. 24). Namely: the laser processing step S26 is performed after the resistor layer forming step S24 and before the protective layer primary forming step S25; and the second protective layer forming step S27 is not performed.

In the thermal head B3, the protective layer 2 has the first region 21 similarly to the thermal heads a1 and B1, and the first region 21 has the plurality of first concave portions 22 and the plurality of first convex portions 23 alternately arranged along the main scanning direction x. Therefore, the thermal head B3 can suppress the occurrence of the blocking phenomenon, similarly to the thermal heads a1 and B1. As can be understood from fig. 35, in the thermal head B3, a level difference d1 is generated between each first concave portion 22 and each first convex portion 23 corresponding to the thickness of the resistor layer 4 (each heat generating portion 41). Thus, the thermal head B3 can form the appropriate height difference d1 while suppressing the sticking phenomenon.

Fig. 37 and 38 show a thermal head B4 according to another modification (third modification) of the second embodiment. Fig. 37 is a sectional view of a main part showing a thermal head B4, corresponding to fig. 23. Fig. 38 is a flowchart showing an example of a method of manufacturing the thermal head B4.

As shown in fig. 37, the thermal head B4 includes the protective layer 2 including the first layer 201 and the second layer 202 without the third layer 203, similarly to the thermal head B3. However, as shown in fig. 37, the thermal head B4 is not divided but connected to the second layer 202 in the first region 21, similarly to the thermal head B3, but is divided in the first region 21 similarly to the heat generating portion 41, unlike the thermal head B3.

In the thermal head B4, a difference in level occurs between a portion where the heat generating portion 41 is disposed and a portion where the heat generating portion 41 is not disposed in the first region 21. Due to this step, irregularities are formed on the surface of the protective layer 2 (the surface of the second layer 202). That is, a plurality of first concave portions 22 and a plurality of first convex portions 23 are formed in the first region 21 of the protective layer 2. As understood from fig. 37, the first convex portions 23 are located in the first region 21 in a region overlapping the heat generating portion 41 when viewed in the thickness direction z, and the first concave portions 22 are located in the first region 21 in a region not overlapping the heat generating portion 41 when viewed in the thickness direction z.

The thermal head B4 is formed by the process shown in fig. 38, for example. As shown in fig. 38, the method of manufacturing the thermal head B4 differs from the method of manufacturing the thermal head B1 (see fig. 24) in the following respects. Namely: the protective layer forming process S252 is performed by the protective layer secondary forming process S27; and the oxide film forming process S271 is not performed in the protective layer secondary forming step S27.

In the thermal head B4, the protective layer 2 also has the first region 21, similarly to the thermal heads a1 and B1, and the first region 21 has a plurality of first concave portions 22 and a plurality of first convex portions 23 alternately arranged along the main scanning direction x. Therefore, the thermal head B4 can suppress the occurrence of the blocking phenomenon as in the thermal heads a1 and B1. As can be understood from fig. 37, in the thermal head B4, a level difference d1 is generated between each first concave portion 22 and each first convex portion 23, which corresponds to the thickness of the resistor layer 4 (each heat generating portion 41) and the thickness of the first layer 201. Thus, the thermal head B4 can form the appropriate height difference d1 while suppressing the sticking phenomenon.

[ third embodiment ]

Fig. 39 to 42 show a thermal head C1 according to a third embodiment. Fig. 39 is a plan view showing the thermal head C1. Fig. 40 is an enlarged plan view of a part of fig. 39, and fig. 41 is a sectional view taken along the XLI-XLI line of fig. 40. FIG. 42 is a cross-sectional view along line XLII-XLII of FIG. 40.

The thermal head C1 has different structures of the head substrate 1, the protective layer 2, the electrode layer 3, and the resistor layer 4 than the thermal heads a1 and B1. In the thermal head C1 shown in fig. 39, the driver ICs 7 are disposed on the connection substrate 5, but the driver ICs 7 may be disposed on the head substrate 1 in the same manner as the thermal heads a1 and B1.

The head substrate 1 of the thermal head C1 has a base material 10 and an insulating layer 19.

The substrate 10 is made of a single crystal semiconductor. The single crystal semiconductor is, for example, Si (silicon). Thus, in the thermal head C1, the constituent material of the base material 10 is different from those of the thermal heads a1 and B1. The substrate 10 has a main surface 11 and a back surface 12. The main surface 11 and the back surface 12 are separated in the thickness direction z and face opposite sides to each other in the thickness direction z.

The substrate 10 also has projections 13. The convex portion 13 protrudes from the main surface 11 in the thickness direction z and extends long in the main scanning direction x. In the illustrated example, the convex portion 13 is formed on the downstream side in the sub-scanning direction y of the base material 10. Since the projection 13 is a part of the base material 10, it is made of Si which is a single crystal semiconductor. The convex portion 13 may not be formed in the base material 10.

The convex portion 13 has a top portion 130, a pair of first

inclined portions

131A, 131B, and a pair of second

inclined portions

132A, 132B.

The top 130 is a portion of the projection 13 having the largest distance from the main surface 11. The top 130 is, for example, a plane substantially parallel to the main surface 11. The top 130 is an elongated rectangular shape extending longer in the main scanning direction x as viewed in the thickness direction z.

The pair of first

inclined portions

131A, 131B are continuous with both sides of the top portion 130 in the sub-scanning direction y as shown in fig. 41. The first inclined portion 131A is connected to the ceiling portion 130 from the upstream side in the sub-scanning direction y. The first slope part 131B is connected to the ceiling part 130 from the downstream side in the sub-scanning direction y. The pair of first

inclined portions

131A, 131B are inclined at only an angle α 1 (inclined at a first inclination angle α 1) with respect to the principal surface 11, respectively. The pair of first

inclined portions

131A and 131B are each an elongated rectangular plane extending long in the main scanning direction x when viewed in the thickness direction z. The convex portion 13 may have an inclined portion (not shown) which is continuous with the pair of first

inclined portions

131A and 131B and is adjacent to both ends of the top portion 130 in the main scanning direction x.

As shown in fig. 41, the pair of second

inclined portions

132A and 132B are connected to the pair of first

inclined portions

131A and 131B from the opposite side to the top portion 130 in the sub-scanning direction y. The second slope part 132A is sandwiched by the first slope part 131A and the main surface 11 in the sub-scanning direction y. The second inclined portion 132A is continuous with the first inclined portion 131A from the upstream side in the sub-scanning direction y, and is continuous with the principal surface 11 from the downstream side in the sub-scanning direction y. The second inclined portion 132B is sandwiched between the first inclined portion 131B and the main surface 11 in the sub-scanning direction y. The second inclined portion 132B is continuous with the first inclined portion 131B from the downstream side in the sub-scanning direction y, and is continuous with the principal surface 11 from the upstream side in the sub-scanning direction y. The pair of second

inclined portions

132A, 132B are inclined at only an angle α 2 (inclined at a second inclination angle α 2) with respect to the principal surface 11, respectively. Angle α 2 is greater than angle α 1. The pair of second

inclined portions

132A, 132B are each an elongated rectangular plane extending long in the main scanning direction x when viewed in the thickness direction z. The pair of second

inclined portions

132A, 132B are connected to the main surface 11, respectively. The convex portion 13 may have inclined portions (not shown) which are continuous with the pair of second

inclined portions

132A, 132B and are located outside the main scanning direction x at both ends of the top portion 130 in the main scanning direction x. The pair of first

inclined portions

131A and 131B may not be provided in the projection 13, and the pair of second

inclined portions

132A and 132B may be connected to the top portion 130.

In the head substrate 1, the main surface 11 is a (100) surface. According to an example of a manufacturing method described later, an angle α 1 (see fig. 41) of each of the first

inclined portions

131A and 131B with respect to the main surface 11 is, for example, 30.1 degrees, and an angle α 2 (see fig. 41) of each of the second

inclined portions

132A and 132B with respect to the main surface 11 is, for example, 54.7 degrees. The dimension z in the thickness direction of the convex portion 13 (the amount of protrusion in the thickness direction z from the main surface 11) is, for example, 150 μm or more and 300 μm or less (170 μm or less in one example).

As shown in fig. 40 to 42, the insulating layer 19 covers the principal surface 11 and the convex portion 13. The insulating layer 19 is configured to insulate the main surface 11 side of the substrate 10 more reliably. The insulating layer 19 is made of an insulating material. For example, SiO formed by using TEOS (tetraethylorthosilicate) as a raw material gas can be used as the insulating material ₂ (TEOS-SiO ₂ ). Can also replace TEOS-SiO ₂ And, for example, SiO formed into a film by another method is used ₂ Or SiN (silicon nitride). The thickness of the insulating layer 19 is not particularly limited, and is about 15 μm in one example.

The insulating layer 19 has a second region 191. The second region 191 is understood from fig. 40 and 42 to overlap the first region 21 as viewed in the thickness direction z. The second region 191 has a plurality of second recesses 192 and a plurality of second protrusions 193. The plurality of second concave portions 192 and the plurality of second convex portions 193 are alternately arranged along the main scanning direction x.

The second recesses 192 are adjacent to the heat generating portions 41, respectively, when viewed in the thickness direction z. Each second recess 192 is sandwiched between 2 heat generating portions 41 adjacent to each other in the main scanning direction x. The heat generating portions 41 (resistor layer 4) are not formed on the second recesses 192. Each of the second recesses 192 is formed by partially removing the insulating layer 19 in a manufacturing method described later. Each second recess 192 does not overlap with the resistor layer 4 when viewed in the thickness direction z. Each of the second projections 193 overlaps the heat generating portion 41 when viewed in the thickness direction z. Each heat generating portion 41 (resistor layer 4) is formed on each second projection 193. The height difference d2 (see fig. 42) between each second concave portion 192 and each second convex portion 193 along the thickness direction z is preferably larger than the thickness t1 of the electrode layer 3, for example.

The electrode layer 3 is supported by the head substrate 1, and in the present embodiment, is stacked on the resistor layer 4 as shown in fig. 41. The electrode layer 3 has a common electrode 31, a plurality of individual electrodes 32, and a plurality of relay electrodes 33.

As shown in fig. 40, each of the plurality of relay electrodes 33 includes 2 strip portions 331 and a coupling portion 332. The 2 strip portions 331 are strip-shaped portions extending in the sub-scanning direction y. The 2 band-shaped portions 331 are arranged substantially parallel to each other with a gap therebetween in the main scanning direction x. The 2 band-shaped portions 331 are connected to the adjacent heat generating portions 41, respectively. In the example shown in fig. 40, the 2 belt-like portions 331 are connected to the heat generating portions 41 from the downstream side in the sub-scanning direction y. The dimensions of the 2 belt-like portions 331 in the main scanning direction x are substantially the same. The coupling portion 332 is connected to the end portion of each of the 2 belt-shaped portions 331 connected thereto and the end portion on the opposite side in the sub-scanning direction y. The coupling portion 332 is a belt-like shape extending in the main scanning direction x. The plurality of relay electrodes 33 are arranged at equal intervals in the main scanning direction x. The relay electrodes 33 are located at positions on the downstream side of the heat generating portions 41 in the sub-scanning direction y.

As shown in fig. 40, the common electrode 31 includes a plurality of straight portions 313, a plurality of branch portions 314, a plurality of strip portions 315, and a coupling portion 316. Each of the plurality of straight portions 313 has a strip shape extending in the sub-scanning direction y. The plurality of straight portions 313 are arranged at equal intervals in the main scanning direction x. A branch portion 314 and 2 band portions 315 are provided on the tip side (downstream side in the sub-scanning direction y) of each of the plurality of straight portions 313. The 2 band-shaped portions 315 are connected to the adjacent heat generating portions 41, respectively. In the example shown in fig. 40, the 2 belt-like portions 315 are connected to the heat generating portion 41 from the upstream side in the sub-scanning direction y. The dimension of each belt 315 in the main scanning direction x is substantially the same as the dimension of each belt 331 in the main scanning direction x. The belt-shaped portion 315 overlaps the belt-shaped portion 331 as viewed in the sub-scanning direction y. The plurality of branch portions 314 are connected to the distal ends of the straight portions 313, respectively. The plurality of branch portions 314 are connected to the respective straight portions 313 at the end portions opposite to the end portions connected to the 2 belt portions 315 in the sub-scanning direction y. The 2 belt-like portions 315 are connected to the heat generating portion 41 from the upstream side in the sub-scanning direction y. The connection portion 316 is located on the base end side (upstream side in the sub-scanning direction y) of the plurality of straight portions 313 and extends in the main scanning direction x. The plurality of straight portions 313 are connected to the connection portions 316, respectively. The connection portion 316 is connected to the connector 59 via the lead 61 and a wire connected to the substrate 5, and is applied with a driving voltage.

As shown in fig. 40, the individual electrodes 32 are arranged at intervals in the main scanning direction x. The belt-shaped portion 321 of each individual electrode 32 is located on the upstream side of the heat generating portion 41 in the sub-scanning direction y. The belt-like portion 321 of each individual electrode 32 is connected to the heat generating portion 41 on the tip side (downstream side in the sub-scanning direction y). The dimension of each belt-shaped portion 321 in the main scanning direction x is substantially the same as the dimension of each belt-shaped portion 331 in the main scanning direction x. The end portion of each strip 321 on the downstream side in the sub-scanning direction y overlaps each strip 331 as viewed in the sub-scanning direction y.

In the thermal head C1, as shown in fig. 40, each straight portion 313 is sandwiched by the strip-shaped portions 321 of the 2 individual electrodes 32. The heat generating portion 41 connected to one of the 2 strip portions 331 of each relay electrode 33 is connected to the strip portion 315, and the heat generating portion 41 connected to the other of the 2 strip portions 331 of the relay electrode 33 is connected to the strip portion 321 of any one of the plurality of individual electrodes 32. Therefore, when each individual electrode 32 is energized, a current flows through the heat generating portion 41 connected thereto and the heat generating portion 41 connected to the heat generating portion 41 via the relay electrode 33, and the heat generating portions 41 generate heat. I.e., 2 heat generating portions 41 generate heat simultaneously.

The electrode layer 3 (the common electrode 31, the plurality of individual electrodes 32, and the plurality of relay electrodes 33) is configured to include a first conductor layer 301 and a second conductor layer 302 stacked in the thickness direction z, as understood from fig. 41.

The first conductor layer 301 is formed on the resistor layer 4. The first conductor layer 301 is made of a material having a lower resistance than the resistor layer 4 and a higher resistance than the second conductor layer 302. As a constituent material of the first conductor layer 301, for example, Ti (titanium) can be used, but Ta, Ga, Sn, PtIr, Pt, Ti (thallium), V (vanadium), Cr, or the like may be used instead of Ti. The method for forming the first conductor layer 301 is not particularly limited, and is formed by, for example, sputtering, CVD, plating, or the like, and is appropriately selected depending on the constituent material used. For example, when the material constituting the first conductor layer 301 is Ti, the first conductor layer 301 is formed by a sputtering method. The thickness of the first conductor layer 301 is not particularly limited, and is about 30nm in one example.

A second conductor layer 302 is formed on the first conductor layer 301. The second conductor layer 302 partially covers the first conductor layer 301. Thus, the first conductor layer 301 has a portion exposed from the second conductor layer 302. The second conductor layer 302 is made of a material having a lower resistance than the resistor layer 4 and the first conductor layer 301. In addition, the second conductor layer 302 is made of a material having higher thermal conductivity than the first conductor layer 301. The material of the second conductor layer 302 is, for example, Cu, but instead of Cu, Cu alloy, Al alloy, Au, Ag, Ni, W (tungsten), or the like may be used. The method for forming the second conductor layer 302 is not particularly limited, and is formed by, for example, sputtering, CVD, plating, or the like, and is appropriately selected depending on the constituent material used. For example, when the constituent material of the second conductor layer 302 is Cu, the second conductor layer 302 is formed by a sputtering method. Note that, when the constituent material of the second conductor layer 302 is Au, Ag, or Ni, the second conductor layer 302 is usually formed by plating, but in this case, the second conductor layer 302 may include a seed layer (e.g., Cu) or the like. The second conductor layer 302 is thicker than the first conductor layer 301. The thickness of the second conductor layer 302 depends on the material used, the value of the current flowing through the electrode layer 3, and the like. The thickness of the second conductor layer 302 is not particularly limited, and is about 800nm in one example.

As shown in fig. 41 and 42, the resistor layer 4 is supported by the head substrate 1 via the insulating layer 19. As a constituent material of the resistor layer 4, TaN (tantalum nitride), for example, may be used, but TaSiO may be used instead of TaN ₂ 、TiON、PolySi、Ta ₂ O ₅ 、RuO ₂ RuTiO or TaSiN, and the like. The method of forming the resistor layer 4 is not particularly limited, and the resistor layer is formed by, for example, sputtering, CVD, plating, or the like, and is appropriately selected according to the constituent material used. For example, when the constituent material of the resistor layer 4 is TaN, the resistor layer 4 is formed by a sputtering method. The thickness of the resistor layer 4 is not particularly limited, and is about 60nm in one example.

The resistor layer 4 of the thermal head C1 is divided into the plurality of heat generating portions 41, similarly to the resistor layer 4 of the thermal head B1. The heat generating portions 41 are formed across the

respective band portions

331 and 321 or across the

respective band portions

331 and 315 when viewed in the thickness direction z.

The protective layer 2 is made of SiN, for example. The constituent material of the protective layer 2 may be SiO instead of SiN ₂ SiC, AlN, etc. The protective layer 2 is formed of a single layer or a plurality of layers including the insulating material. The thickness of the protective layer 2 (the thickness of the portion in contact with the insulating layer 19) is not particularly limited, and is about 3.2 μm in one example.

As shown in fig. 42, the protective layer 2 of the thermal head C1 has the first region 21, similarly to the protective layer 2 of the thermal heads a1 and B1. In the example shown in fig. 40, when viewed in the thickness direction z, both ends of the first region 21 in the sub-scanning direction y overlap with the second concave portions 192, the second convex portions 193, and the resistor layer 4 (the heat generating portions 41). In the first region 21, the plurality of first concave portions 22 and the plurality of first convex portions 23 are alternately arranged along the main scanning direction x. In the thermal head C1, the plurality of first concave portions 22 overlap the respective second concave portions 192 as viewed in the thickness direction z. Further, each of the plurality of first projections 23 overlaps each of the second projections 193 as viewed in the thickness direction z. The first region 21 substantially overlaps the second region 191 as viewed in the thickness direction z. As understood from fig. 42, the first convex portions 23 are located in the first region 21 in a region overlapping the heat generating portion 41 as viewed in the thickness direction z, and the first concave portions 22 are located in the first region 21 in a region not overlapping the heat generating portion 41 as viewed in the thickness direction z.

Next, an example of a method for manufacturing the thermal head C1 will be described with reference to fig. 43 to 55.

Fig. 43 is a flowchart showing an example of the method of manufacturing the thermal head C1. Fig. 44 to 47, 49, and 51 to 53 are sectional views of a main part showing one step of a method of manufacturing the thermal head C1, and correspond to the section of fig. 41. Fig. 48, 50, 54, and 55 are sectional views of a main part showing a step of a method of manufacturing the thermal head C1, and correspond to the section of fig. 42.

As shown in fig. 43, the method of manufacturing the thermal head C1 includes a base material preparation step S31, a base material processing step S32, an insulating layer forming step S33, a resistor film forming step S34, a wiring film forming step S35, a removal step S36, an insulating layer processing step S37, a protective layer forming step S38, a singulation step S391, and an assembly step S392.

[ substrate preparation Process S31 ]

First, as shown in fig. 44, a substrate 10K is prepared. The base material 10K is made of a single crystal semiconductor, and is, for example, a part of a substantially circular Si wafer. The 1 Si wafer includes a plurality of substrates 10K. In the following drawings, 1 base material 10K (head substrate 1) corresponding to 1 thermal head C1 as a part of an Si wafer is shown in some cases. The thickness of the base material 10K (in other words, the thickness of the Si wafer) is not particularly limited, and is, for example, about 725 μm in the present embodiment. As shown in fig. 44, the substrate 10K has a main surface 11K and a back surface 12K facing opposite sides to each other. The main surface 11K is a (100) surface.

[ substrate processing procedure S32 ]

Next, as shown in fig. 45 and 46, the base material 10K is processed to form the convex portions 13 on the base material 10K. In the substrate processing step S32, etching is performed twice.

In the first etching, after the main surface 11K is covered with a predetermined mask layer, anisotropic etching using KOH (potassium hydroxide) is performed, for example. The chemical used for the anisotropic etching may be TMAH (tetramethylammonium hydroxide) instead of KOH, and when KOH is used, the processing speed (etching speed) is high. Thereafter, the mask layer is removed. As a result, as shown in fig. 45, the convex portion 13K is formed on the base material 10K. The convex portion 13K protrudes from the main surface 11K and extends long in the main scanning direction x. The convex portion 13K has a top portion 130K and a pair of inclined portions 132K. The top 130K is a plane parallel to the main surface 11K, and is a (100) plane as the main surface 11K. The top portion 130K is a portion covered by the mask layer described above. The pair of inclined portions 132K are located on both sides of the apex portion 130K in the sub-scanning direction y, and are present between the apex portion 130K and the main surface 11K. The pair of inclined portions 132K are planes inclined with respect to the top portion 130K and the main surface 11K, respectively. The angle formed by each of the pair of inclined portions 132K with the main surface 11K and the top portion 130K is 54.7 degrees.

In the second etching, anisotropic etching using TMAH, for example, is performed. The chemical used in the anisotropic etching may be KOH instead of TMAH, but when TMAH is used, the surface formed by etching (for example, the pair of first

inclined portions

131A and 131B described later) becomes a smooth surface. By this anisotropic etching, as shown in fig. 46, the base 10K becomes the head substrate 1 having the main surface 11, the back surface 12, and the convex portion 13. The convex portion 13 has a top portion 130, a pair of first

inclined portions

131A, 131B, and a pair of second

inclined portions

132A, 132B. The top 130 is a portion serving as the top 130K, and the pair of second

inclined portions

132A and 132B are portions serving as the pair of inclined portions 132K. The pair of first

inclined portions

131A and 131B are portions where the boundary between the top portion 130K and the pair of inclined portions 132K is etched by TMAH. The angle α 1 (see fig. 46) of the first

inclined portions

131A and 131B with respect to the main surface 11 is 30.1 degrees, and the angle α 2 (see fig. 46) of the second

inclined portions

132A and 132B with respect to the main surface 11 is 54.7 degrees.

[ insulating layer Forming Process S33 ]

Next, as shown in fig. 47 and 48, an insulating layer 19 is formed. The insulating layer 19 is formed of SiO formed by using TEOS as a raw material gas by CVD, for example ₂ And deposited on the substrate 10. The method of forming the insulating layer 19 is not limited thereto. The insulating layer 19 is formed to cover the entire main surface 11 and the convex portion 13.

[ resistor film-forming step S34 ]

Next, as shown in fig. 49 and 50, the resistor film 4K is formed. In the resistor film forming step S34, a thin TaN film is formed on the insulating layer 19 by sputtering, for example. The method of forming the resistor film 4K is not limited thereto.

[ Wiring film formation Process S35 ]

Next, as shown in fig. 51 and 52, the wiring film 3K is formed. The wiring film forming process S35 includes a first film forming process S351 and a second film forming process S352.

In the first film formation process S351, as shown in fig. 51, the first conductive film 301K is formed on the resistor film 4K. The first conductive film 301K is formed by, for example, sputtering. The first conductive film 301K is a thin film made of Ti, for example. At this time, the first conductive film 301K covers substantially the entire surface of the resistor film 4K.

In the second film formation process S352, as shown in fig. 52, the second conductive film 302K is formed on the first conductive film 301K. The second conductive film 302K is formed by plating, sputtering, or the like, for example. The second conductive film 302K is made of Cu, for example. At this time, the second conductive film 302K covers substantially the entire surface of the first conductive film 301K.

[ removal step S36 ]

Next, as shown in fig. 53 and 54, the second conductive film 302K, the first conductive film 301K, and the resistor film 4K are partially removed as appropriate. As shown in fig. 43, the removal step S36 includes a first partial removal process S361, a second partial removal process S362, and a third partial removal process S363.

In the first partial removal process S361, the second conductive film 302K is partially removed. In the second partial removal process S362, partial removal of the first conductive film 301K is performed. In the third partial removal process S363, the resistor film 4K is partially removed. The first partial removal process S361, the second partial removal process S362, and the third partial removal process S363 are each performed by, for example, etching. The second conductor layer 302 is formed by the first partial removal process S361, the first conductor layer 301 is formed by the second partial removal process S362, and the resistor layer 4 is formed by the third partial removal process S363. The third partial removal process S363 may be performed before the first partial removal process S361 and the second partial removal process S362. The first conductor layer 301 and the second conductor layer 302 thus formed constitute the electrode layer 3, and the electrode layer 3 has the common electrode 31, the plurality of individual electrodes 32, and the plurality of relay electrodes 33. The formed resistor layer 4 has a plurality of heat generating portions 41, and is divided for each heat generating portion 41.

[ insulating layer processing step S37 ]

Next, as shown in fig. 55, the insulating layer 19 is processed. In the insulating layer processing step S37, for example, resist formation by photolithography, partial removal of the insulating layer 19 by etching, and resist removal are performed in this order. The plurality of second recesses 192 and the plurality of second protrusions 193 are formed in the second region 191 of the insulating layer 19 by the insulating layer processing step S37. As shown in fig. 55, the plurality of second recesses 192 are formed between the heat generating portions 41 adjacent to each other in the main scanning direction x, respectively. Further, a plurality of second protrusions 193 are formed below the heat generating portions 41, respectively. Therefore, in the second region 191, the plurality of second concave portions 192 and the plurality of second convex portions 193 are alternately arranged along the main scanning direction x.

[ protective layer Forming Process S38 ]

Next, the protective layer 2 is formed. The protective layer 2 is formed by depositing SiN on the insulating layer 19, the electrode layer 3 (the first conductor layer 301 and the second conductor layer 302), and the resistor layer 4 by CVD, for example. Further, the protective layer 2 is partially removed by etching or the like, whereby each bonding portion 322 is exposed from the protective layer 2. Thereby, the protective layer 2 as shown in fig. 40 to 42 is formed. Irregularities are formed on the surface of the formed protective layer 2 along the irregularities generated by the second concave portions 192 and the second convex portions 193. That is, the protective layer 2 forms the first region 21 having the plurality of first concave portions 22 and the plurality of first convex portions 23. The plurality of first concave portions 22 and the plurality of first convex portions 23 are alternately arranged along the main scanning direction x.

[ singulation step S391 ] [ Assembly step S392 ]

After that, the thermal head C1 shown in fig. 39 to 42 is manufactured through the above-described singulation step S391 and assembly step S392. The singulation step S391 is performed in the same manner as the singulation steps S161 and S281, and the assembly step S392 is performed in the same manner as the assembly steps S162 and S282.

The function and effect of the thermal head C1 are as follows.

Similarly to the thermal heads a1 and B1, the thermal head C1 has a plurality of first concave portions 22 and a plurality of first convex portions 23 alternately arranged in the main scanning direction x in the first region 21 of the protective layer 2. Therefore, the thermal head C1 can suppress the occurrence of the blocking phenomenon, similarly to the thermal heads a1 and B1.

In the thermal head C1, the height difference d1 in the thickness direction z between each of the plurality of first concave portions 22 and each of the plurality of first convex portions 23 is larger than the thickness t1 in the thickness direction z of the electrode layer 3, similarly to the thermal heads a1 and B1. Therefore, the thermal head C1 can appropriately secure a local gap between the print medium P1 and the protective layer 2 while suppressing the blocking phenomenon, similarly to the thermal heads a1 and B1.

In the thermal head C1, the insulating layer 19 has the second region 191. The second region 191 has a plurality of second recesses 192 and a plurality of second protrusions 193, and the plurality of second recesses 192 and the plurality of second protrusions 193 are alternately arranged along the main scanning direction x. The second region 191 overlaps the first region 21 as viewed in the thickness direction z. According to this structure, the surface of the insulating layer 19 in the second region 191 undulates along the main scanning direction x. Due to the undulation, irregularities (a plurality of first concave portions 22 and a plurality of first convex portions 23) are formed on the surface of the protective layer 2. That is, the difference d1 between the first concave portions 22 and the first convex portions 23 in the first region 21 is equal to the difference d2 between the second concave portions 192 and the second convex portions 193. Therefore, in the thermal head C1, the level difference d2 is larger than the thickness t1 of the electrode layer 3, so that the level difference d1 larger than the thickness t1 of the electrode layer 3 can be formed on the surface of the protective layer 2 in the first region 21. In the thermal head C1, the resistor layer 4 (each heat generating portion 41) is formed on each second projection 193. Therefore, even if the height difference d2 is smaller than the thickness t1 of the electrode layer 3, the height difference d1 can be made larger than the thickness t1 of the electrode layer 3. However, when the height difference d2 is made larger than the thickness t1 of the electrode layer 3, the local gap between the protective layer 2 and the print medium P1 can be made larger, which is preferable in terms of suppressing the blocking phenomenon.

[ fourth embodiment ]

Fig. 56 to 58 show a thermal head D1 according to a fourth embodiment. Fig. 56 is a plan view showing a main part of the thermal head D1, corresponding to fig. 4. In fig. 56, the first region 21 is indicated by a phantom line (two-dot chain line). Fig. 57 is a sectional view of a principal portion along the line LVII-LVII of fig. 56. Fig. 58 is a sectional view of a substantial part along the line LVIII-LVIII of fig. 56.

The thermal head D1 differs from the thermal head a1 in that the resistor layer 4 is formed below the electrode layer 3. In the examples shown in fig. 56 to 58, the glaze layer 14 of the head substrate 1 does not have the partial glaze 15, but the partial glaze 15 may be provided similarly to the thermal heads a1 and B1.

Electrode layer 3 as can be understood from fig. 56, the same portion as the electrode layer 3 (see fig. 4) of the thermal head a1 is provided. Each of the

strip portions

311 and 321 is partially formed on the resistor layer 4. The strip portions 311 and the strip portions 321 are alternately arranged on the resistor layer 4 along the main scanning direction x. The heat generating portions 41 are located between the

belt portions

311 and 321 as viewed in the thickness direction z.

The electrode layer 3 has a seed layer 303 and a plating layer 304. The seed layer 303 is formed by stacking a layer made of Ti and a layer made of Cu, for example. Unlike the seed layer 303, the seed layer 303 may be formed of a layer made of Cu alone. The plating layer 304 is made of, for example, Cu or a Cu alloy. The plating layer 304 is formed by, for example, electrolytic plating. The plating layer 304 is formed on the seed layer 303.

The thickness t2 (see fig. 58) of the electrode layer 3 of the thermal head D1 is larger than the thickness t1 of the electrode layer 3 of the thermal heads a1, B1, and C1. Since the plating layer 304 of the electrode layer 3 of the thermal head D1 is formed by electrolytic plating, the thickness can be easily increased as compared with the case of forming by sputtering, CVD, thick film printing, or the like. Therefore, in the thermal head D1, the difference in height along the thickness direction z between the portion where the electrode layer 3 is formed and the portion where the electrode layer 3 is not formed is larger than the difference in height in the thermal head a1 caused by the presence or absence of the electrode layer 3.

As shown in fig. 58, the protective layer 2 of the thermal head D1 has the first region 21, similarly to the protective layers 2 of the thermal heads a1, B1, and C1. In the example shown in fig. 56, both ends of the first region 21 in the sub-scanning direction y overlap the resistor layer 4 (the heat generating portions 41) when viewed in the thickness direction z. In the first region 21, the plurality of first concave portions 22 and the plurality of first convex portions 23 are alternately arranged along the main scanning direction x. In the thermal head D1, irregularities (the plurality of first concave portions 22 and the plurality of first convex portions 23) are formed on the surface of the protective layer 2 in the first region 21 by the level difference generated by the presence or absence of the electrode layer 3. As understood from fig. 58, each first concave portion 22 is formed in a region of the first region 21 that does not overlap with the electrode layer 3 as viewed in the thickness direction z, and each first convex portion 23 is formed in a region of the first region 21 that overlaps with the electrode layer 3 as viewed in the thickness direction z.

Next, an example of a method for manufacturing the thermal head D1 will be described below with reference to fig. 59 to 67.

Fig. 59 is a flowchart showing an example of the method for manufacturing the thermal head D1. Fig. 60, 62, 64, and 66 are sectional views of essential parts showing a step of the method of manufacturing the thermal head D1, and correspond to fig. 57. Fig. 61, 63, 65, and 67 are sectional views of essential parts showing a step of a method of manufacturing the thermal head D1, and correspond to fig. 58.

As shown in fig. 59, the method of manufacturing the thermal head D1 includes a base material preparation step S41, a glaze formation step S42, a resistor layer formation step S43, an electrode layer formation step S44, a protective layer formation step S45, a singulation step S461, and an assembly step S462.

[ substrate preparation Process S41 ]

First, the substrate 10 is prepared. In the base material preparation step S41, the same procedure as in the base material preparation steps S11 and S21 is performed.

[ glaze formation Process S42 ]

Next, the glaze layer 14 is formed. In the glaze forming step S42, the full-surface glaze 16 is formed on substantially the entire main surface 11. That is, in the glaze forming step S42, the full-surface glaze forming process S123 is performed. The glaze layer 14 is formed of the whole glaze 16 without the partial glaze 15.

[ resistor layer Forming Process S43 ]

Next, as shown in fig. 60 and 61, the resistor layer 4 is formed. The resistor layer forming step S43 is performed in the same manner as the resistor layer forming step S24. The formed resistor layer 4 is in a strip shape having a longitudinal direction in the main scanning direction x when viewed in the thickness direction z (see fig. 56).

[ electrode layer Forming Process S44 ]

Next, the electrode layer 3 is formed. As shown in fig. 59, in the electrode layer forming step S44, the seed layer forming process S441, the plating layer forming process S442, and the removing process S443 are performed at a time.

In the seed layer formation process S441, as shown in fig. 62 and 63, a seed layer 303 is formed. The seed layer 303 has, for example, a Ti layer and a Cu layer stacked on each other. Specifically, in the seed layer forming process S441, after a Ti layer is formed by, for example, sputtering, a Cu layer in contact with the Ti layer is formed by, for example, sputtering. In the seed layer formation process S441, a Cu layer formed by electroless plating may be formed as the seed layer 303, unlike this method.

In the plating layer forming process S442, as shown in fig. 64 and 65, the plating layer 304 is formed by electrolytic plating. The plating layer 304 is made of, for example, Cu or a Cu alloy. Specifically, in the plating layer formation process S442, a resist (not shown) for forming the plating layer 304 is formed by, for example, photolithography. In the formation of the resist, a photosensitive resist is applied so as to cover the entire surface of the seed layer 303, and the photosensitive resist is exposed and developed to be patterned. By this patterning, a part of the seed layer 303 (a part where the plating layer 304 is formed) is exposed. Then, electrolytic plating is performed using the seed layer 303 as a conductive path, whereby a plating layer 304 is formed on the seed layer 303 exposed from the resist. Then, the resist is removed. Thereby, the plating layer 304 shown in fig. 64 and 65 is formed.

In the removal process S443, as shown in fig. 66 and 67, the seed layer 303 exposed from the plating layer 304 is removed. In the removal process S443, the entire surface including the plating layer 304 is etched. Thereby, the electrode layer 3 having the common electrode 31 and the plurality of individual electrodes 32 is formed. In this case, as shown in fig. 67, irregularities can be formed in the thickness direction z by the portion where the electrode layer 3 is formed and the portion where the electrode layer 3 is not formed.

[ protective layer Forming Process S45 ]

Next, the protective layer 2 is formed. The protective layer forming step S45 is performed in the same manner as the protective layer forming step S15. On the surface of the formed protective layer 2, irregularities are formed along the irregularities formed by the presence or absence of the electrode layer 3. That is, the protective layer 2 forms the first region 21 having the plurality of first concave portions 22 and the plurality of first convex portions 23. The plurality of first concave portions 22 and the plurality of first convex portions 23 are alternately arranged along the main scanning direction x.

[ singulation step S461 ] and [ assembly step S462 ]

After that, the thermal head D1 shown in fig. 56 to 58 is manufactured through the singulation step S461 and the assembly step S462. The singulation step S461 is performed in the same manner as the singulation steps S161, S281, and S391, and the assembly step S462 is performed in the same manner as the assembly steps S162, S282, and S392.

The thermal head D1 functions and effects as follows.

Similarly to the thermal heads a1, B1, and C1, the thermal head D1 has a plurality of first concave portions 22 and a plurality of first convex portions 23 alternately arranged in the main scanning direction x formed in the first region 21 of the protective layer 2. Therefore, the thermal head D1 can suppress the occurrence of the blocking phenomenon, similarly to the thermal heads a1, B1, and C1.

In the thermal head D1, the electrode layer 3 has a seed layer 303 and a plating layer 304. Since the plating layer 304 is formed by electrolytic plating, it is easier to secure a thickness than when it is formed by sputtering, CVD, thick-film printing, or the like. That is, the thickness t2 of the electrode layer 3 can be made larger than the thickness t1 of the electrode layer 3 such as the thermal head a 1. Therefore, in the thermal head D1, even if the height difference D1 of the surface in the first region 21 of the protective layer 2 is about the thickness t2 of the electrode layer 3, the blocking phenomenon can be suppressed and an appropriate gap can be secured.

[ fifth embodiment ]

Fig. 68 and 69 show a thermal head E1 of a fifth embodiment. Fig. 68 is a plan view showing a main part of the thermal head E1. Fig. 69 is a sectional view of an essential part along the line LXIX-LXIX of fig. 68.

The thermal head E1 differs from the thermal head a1 in the structure of the glaze layer 14 and the structure of the protective layer 2.

As shown in fig. 68 and 69, the glaze layer 14 of the thermal head E1 is formed of the entire glaze 16 without including the partial glaze 15, for example. In contrast to this example, the glaze layer 14 of the thermal print head E1 may contain a partial glaze 15. In this case, the partial glaze 15 may be divided into a plurality of the separation portions 151 similarly to the thermal head a1, or may not be divided similarly to the thermal head B1.

The protective layer 2 of the thermal head E1 is shown in fig. 68 and 69 and includes a first layer 201 and a second layer 202. The first layer 201 is made of, for example, amorphous glass, and the second layer 202 is made of, for example, SiC.

The protective layer 2 includes a plurality of recesses 2 a. The plurality of recessed portions 2a are recessed from the surface of the first layer 201 (the surface above in the thickness direction z) toward below in the thickness direction z. The depth (dimension in the thickness direction z) of each of the plurality of recessed portions 2a is not particularly limited, and is, for example, about half the thickness (dimension in the thickness direction z) of the first layer 201. Each of the plurality of recessed portions 2a is formed by, for example, laser processing. The plurality of depressed portions 2a are disposed so as to sandwich both of a pair of heat generating portions 41, of any 2 depressed portions 2a adjacent to each other in the main scanning direction x, the pair of heat generating portions 41 being adjacent to each other in the main scanning direction x with the strip-shaped portions 321 of the individual electrodes 32 sandwiched therebetween. For example, as shown in fig. 68 and 69, each of the plurality of recessed portions 2a overlaps with each of the strip portions 311 of the common electrode 31 when viewed in the thickness direction z. Unlike this example, the plurality of concave portions 2a may be formed so as to overlap the plurality of strip-shaped portions 311 and the plurality of strip-shaped portions 321, respectively.

In the thermal head E1, by forming the plurality of recesses 2a in the first layer 201, the second layer 202 formed on the first layer 201 enters the plurality of recesses 2 a. Therefore, the second layer 202 is recessed in the thickness direction z in a region overlapping each recessed portion 2a as viewed in the thickness direction z. A plurality of first recesses 22 are formed on the surface of the protective layer 2 (the surface above the thickness direction z of the second layer 202) by the plurality of recessed portions 2a formed in the first layer 201. Therefore, each of the plurality of first concave portions 22 overlaps each of the plurality of concave portions 2a when viewed in the thickness direction z.

Next, an example of a method for manufacturing the thermal head E1 will be described below with reference to fig. 70 to 72. Fig. 70 is a flowchart showing an example of the method for manufacturing the thermal head E1. Fig. 71 and 72 are sectional views of essential parts showing a step of a method of manufacturing the thermal head E1, and correspond to fig. 69.

As shown in fig. 70, the method of manufacturing the thermal head E1 includes a base material preparation step S51, a glaze formation step S52, an electrode layer formation step S53, a resistor layer formation step S54, a protective layer formation step S55, a singulation step S561, and an assembly step S562.

[ substrate preparation Process S51 ]

First, the substrate 10 is prepared. The base material preparation step S51 is performed in the same manner as the base material preparation steps S11, S21, and S41. Thus, the substrate 10 is a ceramic plate.

[ glaze formation Process S52 ]

Next, the glaze layer 14 is formed. In the glaze forming step S52, a glass paste is thick-film printed on substantially the entire main surface 11, and then the glass paste is fired. Thereby, the full-surface glaze 16 is formed. When the glaze layer 14 contains the partial glaze 15, the partial glaze 15 may be formed before or after the formation of the full-surface glaze 16.

[ electrode layer Forming Process S53 ]

Subsequently, the electrode layer 3 is formed. The electrode layer forming step S53 is performed in the same manner as the electrode layer forming steps S13 and S23.

[ resistor layer Forming Process S54 ]

Next, the resistor layer 4 is formed. The resistor layer forming step S54 is performed in the same manner as the resistor layer forming steps S14 and S24. The formed resistor layer 4 is in a strip shape having a longitudinal direction in the main scanning direction x when viewed in the thickness direction z, and the plurality of strip-shaped portions 311 and the plurality of strip-shaped portions 321 alternately intersect each other when viewed in the thickness direction z.

[ protective layer Forming Process S55 ]

Next, as shown in fig. 71 and 72, the protective layer 2 is formed. In the protective layer forming step S55, the first layer forming process S551, the laser processing process S552, and the second layer forming process S553 are sequentially performed.

In the first layer forming process S551, as shown in fig. 71, the first layer 201 is formed on the entire upper surfaces of the glaze layer 14, the electrode layer 3, and the resistor layer 4 after the resistor layer forming step S54. The first layer 201 is made of, for example, amorphous glass made of, for example, SiO ₂ And (4) forming. The first layer 201 is formed by, for example, thick-film printing a glass paste and then firing the glass paste. In the first layer 201 after the first layer forming process S551, a plurality of concave portions 2a are not formed.

In the laser processing S552, a plurality of concave portions 2a are formed on the first layer 201 as shown in fig. 72 by irradiation of laser light. In the laser processing step S552, the first layer 201 is irradiated with laser light in a region overlapping each of the band-shaped portions 311 as viewed in the thickness direction z. The plurality of recessed portions 2a are formed so as to be recessed from the surface of the first layer 201 above in the thickness direction z toward below in the thickness direction z.

In the second layer forming process S553, the second layer 202 is formed on the first layer 201 after the laser processing process S552. The second layer 202 is made of SiC, for example. The second layer 202 is formed by, for example, sputtering or CVD. The second layer 202 may be an amorphous glass layer, as with the first layer 201 in the thermal head E1, instead of SiC.

[ singulation step S561 ] and [ assembly step S562 ]

After that, the thermal head E1 shown in fig. 68 and 69 is manufactured through the above-described singulation step S561 and the assembly step S562. The singulation step S561 is performed in the same manner as the singulation steps S161, S281, S391, and S461, and the assembly step S562 is performed in the same manner as the assembly steps S162, S282, S392, and S462.

The function and effect of the thermal head E1 are as follows.

Similarly to the thermal heads a1, B1, C1, and D1, the thermal head E1 has a plurality of first recesses 22 and a plurality of first projections 23 alternately arranged in the main scanning direction x in the first region 21 of the protective layer 2. Therefore, the thermal head E1 can suppress the occurrence of the blocking phenomenon similarly to the thermal heads a1, B1, C1, and D1.

In the thermal head E1, the plurality of recessed portions 2a overlap the boundaries of the plurality of heat generating portions 41 as viewed in the thickness direction z. According to this structure, the thickness of the first layer 201 as the heat storage layer becomes thinner at the boundary portion of the plurality of heat generation portions 41. This can suppress the diffusion of heat in the main scanning direction x among the plurality of heat generating portions 41. Therefore, the thermal head E1 can improve the printing quality and improve the printing efficiency.

In the thermal head E1, the depth (dimension in the thickness direction z) of each of the plurality of recessed portions 2a is, for example, about half the thickness (dimension in the thickness direction z) of the first layer 201. Thus, the thermal head E1 can make the height difference d1 along the thickness direction z between each of the plurality of first concave portions 22 and each of the plurality of first convex portions 23 larger than the thickness t1 along the thickness direction z of the electrode layer 3. Therefore, the thermal head E1 can appropriately secure a local gap between the print medium P1 and the protective layer 2 while suppressing the blocking phenomenon, similarly to the thermal head a 1.

Fig. 73 shows a thermal head E2 according to a modification (first modification) of the fifth embodiment and a method for manufacturing the same. Fig. 73 is a sectional view of a main part of the thermal head E2, corresponding to fig. 69. Fig. 74 is a flowchart showing an example of the method for manufacturing the thermal head E2.

Unlike the thermal head E1, the thermal head E2 has a plurality of recesses 2a formed in the second layer 202. The plurality of recessed portions 2a shown in fig. 73 are recessed from the surface of the second layer 202 above in the thickness direction z toward below in the thickness direction z. As understood from fig. 73, the plurality of recessed portions 2a overlap with the respective band portions 311 as viewed in the thickness direction z. In the thermal head E2, the first recess 22 is formed by the plurality of recessed portions 2a formed in the second layer 202.

The thermal head E2 is formed by, for example, the steps shown in fig. 74. As shown in fig. 74, the method of manufacturing the thermal head E2 differs from the method of manufacturing the thermal head E1 (see fig. 70) in the following respects. Namely: in the protective layer forming step S55, the first layer forming process S551, the second layer forming process S553, and the laser processing process S552 are performed in this order.

According to the process sequence shown in fig. 74, since the second layer forming process S553 is performed after the first layer forming process S551, none of the plurality of recessed portions 2a is formed in the first layer 201. Further, since the laser processing S552 is performed after the second layer forming process S553, a plurality of concave portions 2a are formed in the second layer 202. In the laser processing step S552, the second layer 202 is irradiated with laser light in a region overlapping each band-shaped portion 311 as viewed in the thickness direction z.

The steps other than the protective layer forming step S55 are the same as the method for manufacturing the thermal head E1. Therefore, since the processing procedure in the protective layer forming step S55 is different from that of the thermal head E1 described above, the thermal head E2 shown in fig. 73 can be manufactured.

In the thermal head E2, the protective layer 2 also has the first region 21, and the first region 21 has the plurality of first concave portions 22 and the plurality of first convex portions 23 alternately arranged along the main scanning direction x, similarly to the thermal head E1. Therefore, the thermal head E2 can suppress the occurrence of the blocking phenomenon as in the thermal head E1. In the thermal head E2, heat diffusion in the main scanning direction x among the plurality of heat generating portions 41 can be suppressed, similarly to the thermal head E1.

In the thermal head E2, the plurality of recesses 2a formed in the second layer 202 are arranged in a dot-like wave pattern (for example, in a matrix or in a zigzag pattern) when viewed in the thickness direction z, as shown in fig. 75. The arrangement of the plurality of concave portions 2a is not particularly limited, and it is preferable that each concave portion 2a (each first concave portion 22) is formed at a position overlapping each band-shaped portion 311 as viewed in the thickness direction z as shown in fig. 75 in addition to suppressing heat diffusion between the plurality of heat generating portions 41 in the main scanning direction x.

Fig. 76 to 79 show a thermal head E3 and a method of manufacturing the same according to a modification (second modification) of the fifth embodiment. Fig. 76 is a plan view showing a main part of the thermal head E3. Fig. 77 is a plan view of a main portion of fig. 76 with the protective layer 2 omitted. However, in fig. 77, the first region 21 (the plurality of first concave portions 22 and the plurality of first convex portions 23) is shown by a phantom line. FIG. 78 is a sectional view taken along line LXXVIII-LXXVIII of FIG. 76. Fig. 79 is a flowchart showing an example of a method of manufacturing the thermal head E3.

Unlike the thermal heads E1 and E2, the thermal head E3 has a plurality of recesses 2a not formed in the protective layer 2, and a plurality of recesses 141 formed in the glaze layer 14.

The plurality of recesses 141 are formed in the entire glaze 16 of the glaze layer 14. In the example where the glaze layer 14 includes the partial glaze 15, the plurality of recesses 141 are formed in the partial glaze 15. The plurality of recessed portions 141 are each recessed in the thickness direction z from the surface of the entire glaze 16 above the thickness direction z. As shown in fig. 77, each of the plurality of recessed portions 141 is stripe-shaped when viewed in the thickness direction z and extends in the sub-scanning direction y. The plurality of concave portions 141 are formed in regions overlapping the first region 21 when viewed in the thickness direction z, and are respectively disposed between the strip-shaped

portions

311 and 321 adjacent to each other in the main scanning direction x.

In the thermal head E3, the glaze layer 14 is formed with a plurality of recesses 141, and thus the resistor layer 4, the first layer 201, and the second layer 202 formed on the plurality of recesses 141 are each recessed in the thickness direction z. That is, the plurality of first concave portions 22 can be formed on the surface of the protective layer 2 (the surface above the second layer 202 in the thickness direction z) by the plurality of concave portions 141 formed in the glaze layer 14. Therefore, each of the plurality of first concave portions 22 overlaps each of the plurality of concave portions 141 as viewed in the thickness direction z.

The thermal head E3 is formed by, for example, the steps shown in fig. 79. As shown in fig. 78, the method of manufacturing the thermal head E3 differs from the method of manufacturing the thermal head E1 (see fig. 70) in the following points. Namely: the laser processing S552 is not performed in the protective layer forming step S55; and a laser processing step S57 between the electrode layer forming step S53 and the resistor layer forming step S54.

[ laser processing procedure S57 ]

In the same manner as the method for manufacturing the thermal head E1, when the process proceeds to the electrode layer forming step S53, the glaze layer 14 (the entire glaze 16) is irradiated with the laser beam to form the plurality of concave portions 141. In the laser processing step S57, the surface of the glaze layer 14 (the entire glaze 16) is irradiated with laser light at the portions exposed between the strip-shaped

portions

311 and 321 adjacent to each other in the main scanning direction x. The laser light is irradiated between the

strip portions

311 and 321 in the sub-scanning direction y. The glaze layer 14 is irradiated with the laser beam to form a plurality of recesses 141.

Subsequently, after the resistor layer forming step S54 and the protective layer forming step S55 are sequentially performed, irregularities (the plurality of first concave portions 22 and the plurality of first convex portions 23) are formed on the surface of the protective layer 2. Then, the thermal head E3 shown in fig. 76 to 78 is manufactured through the singulation step S561 and the assembly step S562.

In the thermal head E3 as well, the protective layer 2 has the first region 21, and the first region 21 has the plurality of first concave portions 22 and the plurality of first convex portions 23 alternately arranged along the main scanning direction x, as in the thermal head E1. Therefore, the thermal head E3 can suppress the occurrence of the blocking phenomenon as in the thermal head E1.

In the thermal head E3, the depths (dimensions in the thickness direction z) of the plurality of recessed portions 141 are not particularly limited, and the depths (dimensions in the thickness direction z) of the plurality of recessed portions 141 are set so that the height difference d1 between each of the plurality of first recessed portions 22 and each of the plurality of first raised portions 23 along the thickness direction z is larger than the thickness t1 of the electrode layer 3 along the thickness direction z, whereby the blocking phenomenon is suppressed and the local gap between the printing medium P1 and the protective layer 2 can be appropriately secured.

In the thermal heads E1 to E3, the case where the plurality of strip-shaped portions 311 and the plurality of strip-shaped portions 321 are alternately arranged in the main scanning direction x in the electrode layer 3 is shown, but the present invention is not limited to this, and for example, the strip-shaped portions 311 and the strip-shaped portions 321 may be arranged with a gap in the sub scanning direction y as in the thermal head B1. In this case, each depressed portion 2a or each depressed portion 141 is formed between 2 heat generating portions 41 adjacent in the main scanning direction x as viewed in the thickness direction z.

The thermal head, the thermal printer, and the method of manufacturing the thermal head of the present invention are not limited to the above-described embodiments. The thermal head and the specific structure of each part of the thermal printer and the specific process of the method for manufacturing the thermal head according to the present invention can be freely modified in design. For example, the thermal head, the thermal printer, and the method of manufacturing the thermal head according to the present invention include the embodiments described in the attached notes below.

[ appendix 1 ]

A thermal print head, comprising:

a substrate having a main surface facing one side in a thickness direction;

a resistor layer which is arranged on the main surface and includes a plurality of heat generation portions arranged in a main scanning direction;

an electrode layer disposed on the main surface and constituting a conduction path for conducting electricity to the plurality of heat generating portions; and

a protective layer covering the resistor layer and the electrode layer,

the protective layer has a first region that overlaps the plurality of heat generation portions as viewed in the thickness direction and extends in a main scanning direction as viewed in the thickness direction,

the first region has a plurality of first concave portions and a plurality of first convex portions alternately arranged along a main scanning direction.

[ Note 2 ]

The thermal head according to supplementary note 1, wherein,

the electrode layer includes a plurality of first strip portions and a plurality of second strip portions each having a longitudinal direction in a sub-scanning direction,

each of the plurality of heat generating portions is connected to each of the first band-shaped portions and each of the second band-shaped portions, and is sandwiched between each of the first band-shaped portions and each of the second band-shaped portions, as viewed in the thickness direction.

[ additional note 3 ]

The thermal head according to supplementary note 2, wherein,

further comprising a glaze layer formed on the main surface,

the electrode layer is formed on the glaze layer.

[ tag 4 ]

The thermal head according to supplementary note 3, wherein,

the glaze layer includes a partial glaze partially disposed on the main surface,

the partial glaze includes a plurality of separated portions spaced apart from each other,

the plurality of separating portions are arranged along a main scanning direction,

each of the plurality of first convex portions overlaps with each of the plurality of separation portions when viewed in the thickness direction.

[ tag 5 ]

The thermal head according to supplementary note 4, wherein,

the glaze layer also comprises a whole-surface glaze,

the partial glaze is formed on the main surface,

the full-surface glaze covers the partial glaze and the main surface exposed from the partial glaze.

[ appendix note 6 ]

The thermal head according to

supplementary note

4 or 5, wherein,

the resistor layer extends in a main scanning direction and is formed across the plurality of separation portions as viewed in the thickness direction.

[ additional note 7 ]

The thermal head according to supplementary note 6, wherein,

the plurality of first belt-shaped portions and the plurality of second belt-shaped portions are alternately arranged in the main scanning direction,

a part of each of the plurality of first strip-shaped portions overlaps the resistor layer when viewed in the thickness direction,

a part of each of the second strip portions overlaps the resistor layer when viewed in the thickness direction.

[ tag 8 ]

The thermal head according to supplementary note 3, wherein,

the resistor layer is formed so as to straddle each of the first strip-shaped portions and each of the second strip-shaped portions when viewed in the thickness direction,

the protective layer includes a first layer and a second layer stacked in the thickness direction,

the first layer is formed on the resistor layer,

the second layer is formed on the first layer.

[ tag 9 ]

The thermal head according to supplementary note 8, wherein,

the resistor layer is divided for each of the plurality of heat generating portions,

the first layer and the second layer are divided for each of the plurality of heat generating portions in a portion overlapping the first region as viewed in the thickness direction and are arranged on each of the plurality of heat generating portions,

each of the plurality of first recesses overlaps with each of the plurality of heat generating portions when viewed in the sub-scanning direction.

[ attached note 10 ]

The thermal head according to supplementary note 9, wherein,

each of the first band-shaped portions and each of the second band-shaped portions are arranged in the sub-scanning direction.

[ additional note 11 ]

The thermal head according to supplementary note 10, wherein,

the protective layer further includes a third layer formed on the second layer,

the third layer covers the plurality of heat generating portions, the first layer, and the second layer.

[ additional note 12 ]

The thermal head according to supplementary note 8, wherein,

the protective layer includes a plurality of first recessed portions overlapping with each of the plurality of first recessed portions as viewed in the thickness direction,

each of the first recessed portions is recessed in the thickness direction from a surface facing in the same direction as the main surface in any of the first layer and the second layer.

[ appendix note 13 ]

The thermal head according to supplementary note 12, wherein,

the resistor layer intersects with the plurality of first strip-shaped portions and the plurality of second strip-shaped portions, respectively, when viewed in the thickness direction,

the plurality of first recessed portions overlap boundaries of the plurality of heat generating portions when viewed in the thickness direction.

[ tag 14 ]

The thermal head according to supplementary note 13, wherein,

the electrode layer further includes a connection portion connected to each of the first strip portions,

the plurality of first recessed portions overlap with each of the plurality of first strip portions as viewed in the thickness direction.

[ tag 15 ]

The thermal head according to supplementary note 12, wherein,

each of the plurality of first recesses is formed in the second layer, and is formed in a dot shape when viewed in the thickness direction.

[ additional note 16 ]

The thermal head according to supplementary note 3, wherein,

the glaze layer is formed with a plurality of second recessed portions that overlap each of the plurality of first recessed portions as viewed in the thickness direction and are recessed from a surface facing in the same direction as the main surface in the thickness direction,

each of the plurality of second recessed portions extends in the sub-scanning direction and is formed between each of the plurality of first strip-shaped portions and each of the plurality of second strip-shaped portions.

[ tag 17 ]

The thermal print head according to any one of supplementary notes 1 to 16, wherein,

the substrate is composed of ceramic.

[ appendix 18 ]

The thermal head according to supplementary note 2, wherein,

the substrate is composed of a single crystal semiconductor.

[ tag 19 ]

The thermal head according to supplementary note 18, wherein,

further comprising an insulating layer formed on the main surface,

the resistor layer is formed on the insulating layer so that a part of the insulating layer is exposed,

the electrode layer is formed on the resistor layer so that the plurality of heat generating portions are exposed,

the insulating layer has a second region overlapping with the first region as viewed in the thickness direction,

the second region has a plurality of second concave portions and a plurality of second convex portions alternately arranged along the main scanning direction,

each of the first concave portions overlaps with each of the second concave portions when viewed in the thickness direction.

[ tag 20 ]

The thermal head according to supplementary note 19, wherein,

the base material has a third convex portion protruding from the main surface and extending in the main scanning direction,

the first region and the second region are located above the third convex portion.

[ appendix 21 ]

The thermal print head according to any one of supplementary notes 2 to 20, wherein,

the difference in height along the thickness direction between each of the plurality of first concave portions and each of the plurality of first convex portions is larger than the thickness along the thickness direction of the electrode layer.

[ appendix note 22 ]

The thermal head according to supplementary note 2, wherein,

further comprising a glaze layer formed on the main surface,

the resistor layer is formed on the glaze layer and extends in a main scanning direction,

each of the first strip portions and each of the second strip portions are alternately arranged in a main scanning direction and overlap the resistor layer when viewed in the thickness direction,

each of the plurality of first recesses overlaps with each of the plurality of heat generating portions when viewed in the thickness direction.

[ tag 23 ]

The thermal head according to supplementary note 22, wherein,

the electrode layer includes a plating layer formed of copper or a copper alloy.

[ appendix note 24 ]

A thermal printer, comprising:

the thermal print head described in any one of supplementary notes 1 to 23; and

and the platen is opposite to the thermal printing head.

[ attached note 25 ]

A method of manufacturing a thermal print head, comprising:

preparing a base material having a main surface facing one side in a thickness direction;

forming a resistor layer which is arranged on the main surface and includes a plurality of heat generating portions arranged in a main scanning direction;

forming an electrode layer which is arranged on the main surface and constitutes a conduction path to the plurality of heat generating portions;

a step of forming a protective layer covering the resistor layer and the electrode layer,

Claims

1. A thermal print head, comprising:

a substrate having a main surface facing one side in a thickness direction;

a protective layer covering the resistor layer and the electrode layer,

2. The thermal print head of claim 1, wherein:

3. The thermal print head of claim 2, wherein:

further comprising a glaze layer formed on the main surface,

the electrode layer is formed on the glaze layer.

4. The thermal print head of claim 3, wherein:

5. The thermal print head of claim 4, wherein:

the glaze layer also comprises a whole-surface glaze,

the partial glaze is formed on the main surface,

6. The thermal print head according to claim 4 or 5, wherein:

7. The thermal print head of claim 6, wherein:

8. The thermal print head of claim 3, wherein:

the first layer is formed on the resistor layer,

the second layer is formed on the first layer.

9. The thermal print head of claim 8, wherein:

the first layer and the second layer are divided into the plurality of heat generating portions in a portion overlapping the first region, respectively, and are arranged on each of the plurality of heat generating portions,

10. The thermal print head of claim 9, wherein:

11. The thermal print head of claim 10, wherein:

the protective layer further includes a third layer formed on the second layer,

12. The thermal print head of claim 8, wherein:

13. The thermal print head of claim 12, wherein:

14. The thermal print head of claim 13, wherein:

15. The thermal print head of claim 12, wherein:

16. The thermal print head of claim 3, wherein:

the glaze layer is formed with a plurality of second recessed portions that overlap with each of the plurality of first recessed portions as viewed in the thickness direction and are recessed from a surface facing in the same direction as the main surface in the thickness direction,