Thermal print head and manufacturing method thereof

Abstract

To provide a thermal print head capable of efficiently monitoring etching conditions of a plurality of individual wirings.SOLUTION: A thermal print head 1 comprises a plurality of individual wirings 25 and a monitor pattern 65. Each of the plurality of individual wirings 25 has an individual wiring region 25a extending in a direction inclined to a sub-scanning direction Y. The monitor pattern 65 includes a plurality of band-shaped bodies 66. Each of the plurality of band-shaped bodies 66 extends in the sub-scanning direction Y. A width W2 of the band-shaped body 66 is equal to a width W1 of the individual wiring region 25a. An interval G2 between the band-shaped bodies 66 adjacent to each other is equal to an interval G1 between first individual wiring regions 25a adjacent to each other.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a thermal printhead and a method for manufacturing the same. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2023-176504 (Patent Document 1) discloses a thermal printhead including a substrate, a glaze layer, a wiring layer, and a heating resistor. The wiring layer includes a common electrode, a plurality of individual electrodes, a plurality of signal wiring portions, and a plurality of pad portions. The wiring layer is a conductor primarily composed of silver. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-176504

[0004] [overview] An object of the present disclosure is to provide a thermal printhead that can efficiently monitor the etching conditions of multiple individual wirings, and a method for manufacturing the same.

[0005] The thermal printhead of the present disclosure includes a plurality of individual wirings and a monitor pattern. Each of the plurality of individual wirings includes a first individual wiring region extending in a direction inclined with respect to the sub-scanning direction. The monitor pattern includes a plurality of bands. Each of the plurality of bands extends in the sub-scanning direction. The plurality of bands are arranged in the main scanning direction and are formed of the same material as the first individual wiring region. The width of each of the plurality of bands is equal to the width of each of the first individual wiring regions of the plurality of individual wirings. The spacing between adjacent bands among the plurality of bands is equal to the spacing between adjacent first individual wiring regions among the first individual wiring regions of the plurality of individual wirings. [Brief explanation of the drawings]

[0006] [Figure 1]FIG. 1 is a schematic plan view of a thermal printhead according to an embodiment. [Figure 2] FIG. 2 is a schematic, partially enlarged cross-sectional view of the thermal printhead according to the embodiment taken along the line II-II in FIG. [Figure 3] FIG. 3 is a schematic partial enlarged plan view of the region III shown in FIG. 1 of the thermal printhead according to the embodiment. [Figure 4] FIG. 4 is a schematic partial enlarged plan view of the region IV shown in FIG. 1 of the thermal printhead according to the embodiment. [Figure 5] FIG. 5 is a schematic partial enlarged plan view of a thermal printhead according to a first modified example of the embodiment. [Figure 6] FIG. 6 is a schematic partial enlarged plan view of a thermal printhead according to a second modified example of the embodiment. [Figure 7] FIG. 7 is a schematic partial enlarged plan view of a thermal printhead according to a third modified example of the embodiment. [Figure 8] FIG. 8 is a flowchart illustrating an example of a method for manufacturing a thermal printhead according to an embodiment. [Figure 9] FIG. 9 is a flowchart showing another example of the method for manufacturing the thermal printhead according to the embodiment.

[0007] [Detailed explanation] The details of the embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and the description thereof will not be repeated. At least some of the configurations of the embodiments described below may be combined in any manner.

[0008] A thermal printhead 1 according to an embodiment will be described with reference to Figures 1 to 7. The thermal printhead 1 according to this embodiment includes a substrate 10, a glaze 11, a planarizing layer 15, first wiring 20, a monitor pattern 65, a heating resistor 30, a protective layer 33, a drive circuit 40, a conductive wire 41, a sealing member 43, a plurality of second wirings 45, and a plurality of external connection terminals 50. The thermal printhead 1 according to this embodiment may further include a connector 61.

[0009] 1 and 2, the substrate 10 is a ceramic substrate such as an alumina substrate. The substrate 10 has a main surface 10a. In a plan view of the main surface 10a (hereinafter simply referred to as "plan view"), the longitudinal direction of the substrate 10 is the main scanning direction X, the lateral direction of the substrate 10 is the sub-scanning direction Y, and the thickness direction of the substrate 10 is the plate thickness direction Z. The plate thickness direction Z is perpendicular to the main scanning direction X and the sub-scanning direction Y. In the plan view, the sub-scanning direction Y is the transport direction of a print medium (e.g., thermal recording paper).

[0010] 1 to 7, glaze 11 is disposed on main surface 10a of substrate 10. Glaze 11 is formed of a glass material such as amorphous glass. The thermal conductivity of glaze 11 may be lower than the thermal conductivity of substrate 10. As shown in FIGS. 1 and 2, glaze 11 is provided on a portion of main surface 10a. That is, glaze 11 is a so-called partial glaze. Glaze 11 includes heater glaze 12 and die bonding glaze 13.

[0011] The heater glaze 12 extends in the main scanning direction X in a plan view of the main surface 10a and has a band shape. The heater glaze 12 is disposed below the heating resistor 30. The heater glaze 12 prevents heat from the heating resistor 30 from dissipating to the substrate 10. The heater glaze 12 is a heat storage layer. The heater glaze 12 protrudes from a portion of the main surface 10a. The heater glaze 12 increases the height of the heating resistor 30 from the main surface 10a. The heating resistor 30 is pressed against a print medium (e.g., thermal recording paper).

[0012] The die bonding glaze 13 is disposed upstream of and spaced apart from the heater glaze 12 in the sub-scanning direction Y. In a plan view of the main surface 10a, the die bonding glaze 13 extends in the main scanning direction X and has a band shape. The die bonding glaze 13 supports a part of the first wiring 20 and the drive circuit 40.

[0013] 1 to 7, the planarization layer 15 is disposed on the main surface 10a. The planarization layer 15 is formed of, for example, glass. The planarization layer 15 includes a first planarization layer 16 and a second planarization layer 17. The first planarization layer 16 is disposed between the heater glaze 12 and the die bonding glaze 13 in a plan view of the main surface 10a. The second planarization layer 17 is disposed away from the first planarization layer 16 on the downstream side in the sub-scanning direction Y. The second planarization layer 17 is disposed on the opposite side of the heater glaze 12 from the first planarization layer 16 in the sub-scanning direction Y.

[0014] The thickness of the planarizing layer 15 is smaller than the thickness of the glaze 11. Specifically, the thickness of the planarizing layer 15 is smaller than the thickness of the heater glaze 12. The thickness of the planarizing layer 15 is smaller than the thickness of the die bonding glaze 13. The height of the top surface of the heater glaze 12 from the surface of the planarizing layer 15 is smaller than the height of the top surface of the heater glaze 12 from the main surface 10a. The height of the top surface of the die bonding glaze 13 from the surface of the planarizing layer 15 is smaller than the height of the top surface of the die bonding glaze 13 from the main surface 10a. The planarizing layer 15 can prevent breaks in the first wiring 20 due to roughness of the main surface 10a and steps between the main surface 10a and the glaze 11.

[0015] 1 to 7, the first wiring 20 is disposed on the glaze 11 and the planarizing layer 15. The first wiring 20 forms a conductive path for supplying electricity to the heating resistor 30. The first wiring 20 includes a common wiring 21 and a plurality of individual wirings 25.

[0016] The common wiring 21 is disposed on the heater glaze 12, the die bonding glaze 13, the first planarization layer 16, and the second planarization layer 17. The common wiring 21 includes a plurality of strip portions 22, a connecting portion 23, and a detour portion 24.

[0017] The plurality of strip-shaped portions 22 are disposed on the heater glaze 12 and the second planarizing layer 17. Each of the plurality of strip-shaped portions 22 extends in the sub-scanning direction Y. The plurality of strip-shaped portions 22 are arranged at equal pitches in the main scanning direction X. The plurality of strip-shaped portions 22 are, for example, gold (Au) wiring. The plurality of strip-shaped portions 22 are, for example, formed of a gold particle sintered body.

[0018] The connecting portions 23 are disposed on the second planarizing layer 17. The connecting portions 23 extend in the main scanning direction X. The connecting portions 23 are connected to the plurality of strip-shaped portions 22, and connect the plurality of strip-shaped portions 22 together. The connecting portions 23 are, for example, silver (Ag) wiring. The connecting portions 23 are, for example, formed of a silver particle sintered body.

[0019] The detour portion 24 is connected to the connecting portion 23. The detour portion 24 extends from both ends of the connecting portion 23 in the main scanning direction X to the upstream side in the sub-scanning direction Y so as to detour around the multiple individual wirings 25. The detour portion 24 is disposed on the second planarization layer 17, the heater glaze 12, the first planarization layer 16, and the die bonding glaze 13. The detour portion 24 is, for example, a silver (Ag) wiring. The detour portion 24 is, for example, formed of a silver particle sintered body. Because the connecting portion 23 and the detour portion 24 contain silver (Ag) rather than gold (Au) as the main component, the cost of the thermal printhead 1 can be reduced.

[0020] Each of the plurality of individual wires 25 partially conducts current to the heating resistor 30. The plurality of individual wires 25 are disposed on the heater glaze 12, the die bonding glaze 13, and the first planarization layer 16. As shown in FIG. 2 , each of the plurality of individual wires 25 includes a first individual wire portion 26 and a second individual wire portion 27.

[0021] The first individual wiring portions 26 are disposed on the heater glaze 12 and the first planarizing layer 16. The first individual wiring portions 26 are, for example, gold (Au) wiring. The first individual wiring portions 26 are, for example, formed of a gold particle sintered body.

[0022] The second individual wiring portion 27 is connected to the first individual wiring portion 26. The second individual wiring portion 27 is disposed on the die bonding glaze 13 and the first planarization layer 16. The second individual wiring portion 27 is, for example, a silver (Ag) wiring. The second individual wiring portion 27 is formed, for example, of a silver particle sintered body. The second individual wiring portion 27 contains silver (Ag) rather than gold (Au) as a main component, thereby reducing the cost of the thermal printhead 1. The second individual wiring portion 27 may be a laminate of a first layer 28 and a second layer 29. The first layer 28 is formed, for example, of a silver particle sintered body. The second layer 29 is formed, for example, of frit glass containing silver particles.

[0023] As shown in FIG. 1, in a plan view, the plurality of individual wirings 25 include individual wiring regions 25a, 25b, and 25c, respectively.

[0024] The individual wiring region 25a is a portion of the individual wiring 25 that is disposed on the first planarization layer 16. The individual wiring region 25a extends in a direction inclined with respect to the sub-scanning direction Y. The individual wiring region 25a is formed by a second individual wiring portion 27. The individual wiring region 25a is longer than the individual wiring region 25b and also longer than the individual wiring region 25c.

[0025] The individual wiring region 25b is connected to one end of the individual wiring region 25a. The individual wiring region 25b is a portion of the individual wiring 25 that is disposed on the heater glaze 12, and is electrically connected to the heating resistor 30. The individual wiring region 25b extends in the sub-scanning direction Y. The individual wiring region 25b is formed by a first individual wiring portion 26.

[0026] The individual wiring region 25c is connected to the other end of the individual wiring region 25a. The individual wiring region 25c is a portion of the individual wiring 25 that is disposed on the die bonding glaze 13, and is electrically connected to the drive circuit 40. The individual wiring region 25c extends in the sub-scanning direction Y. The individual wiring region 25c is formed by a second individual wiring portion 27.

[0027] The individual wiring area 25a is the portion of the individual wiring 25 that is most inclined with respect to the sub-scanning direction Y. Therefore, the distance G1 (see FIGS. 4 to 7) between adjacent individual wiring areas 25a is smaller than the distance between adjacent individual wiring areas 25b and is also smaller than the distance between adjacent individual wiring areas 25c. The width W1 (see FIGS. 4 to 7) of the individual wiring area 25a is smaller than the width of the individual wiring area 25b and is also smaller than the width of the individual wiring area 25c. In this specification, the distance between adjacent individual wiring areas means the distance between the individual wiring areas in a direction perpendicular to the longitudinal direction of the individual wiring area. The width of the individual wiring area means the width of the individual wiring area in a direction perpendicular to the longitudinal direction of the individual wiring area.

[0028] 1 and 4 to 7, the monitor pattern 65 is disposed on the first planarization layer 16. In a plan view of the main surface 10a, the monitor pattern 65 is disposed near the individual wiring region 25a. For example, the monitor pattern 65 is disposed near the individual wiring 25 located at the endmost position in the main scanning direction among the plurality of individual wirings 25. The individual wiring 25 located at the endmost position in the main scanning direction among the plurality of individual wirings 25 is the individual wiring 25 that is most inclined with respect to the sub-scanning direction Y among the plurality of individual wirings 25. The monitor pattern 65 may be disposed away from the individual wiring region 25a in the main scanning direction X, or may be disposed away from the individual wiring region 25a in the sub-scanning direction Y.

[0029] The monitor pattern 65 includes a plurality of strips 66. Each of the strips 66 extends in the sub-scanning direction Y. The strips 66 are arranged in the main scanning direction X. The width W2 (see FIGS. 4 to 7) of each of the strips 66 is equal to the width W1 (see FIGS. 4 to 7) of the individual wiring region 25a. The spacing G2 (see FIGS. 4 to 7) between adjacent strips 66 is equal to the spacing G1 (see FIGS. 4 to 7) between adjacent individual wiring regions 25a. The strips 66 are formed from the same material as the individual wiring region 25a. The strips 66 and the individual wiring region 25a may be formed together.

[0030] The monitor pattern 65 includes a central band 66c, which is located at the center of the multiple bands 66 in the main scanning direction X. The monitor pattern 65 includes a marker 67 that identifies the central band 66c. As shown in FIGS. 4 and 5, the central band 66c is formed longer than the other bands 66, and the marker 67 may be a portion of the central band 66c that is longer than the other bands 66. Specifically, as shown in FIG. 4, the central band 66c may be formed longer on the side opposite the heater glaze 12 (upstream in the sub-scanning direction Y) than the other bands 66, or as shown in FIG. 5, it may be formed longer on the heater glaze 12 side (downstream in the sub-scanning direction Y) than the other bands 66. As shown in FIG. 6, the central band 66c is formed shorter than the other bands 66, and the marker 67 may be a non-formed portion of the central band 66c. As shown in FIG. 7, the markers 67 may be formed longitudinally of the central band 66c and spaced apart from the central band 66c.

[0031] 1 to 3, the heating resistor 30 is disposed on the heater glaze 12 (more specifically, on the top of the heater glaze 12). The heating resistor 30 extends in the main scanning direction X and has a band shape in a plan view. The heating resistor 30 protrudes from the heater glaze 12 on the side opposite to the substrate 10.

[0032] The heating resistor 30 is connected to the first wiring 20. Specifically, the heating resistor 30 is connected to the plurality of strip portions 22 of the common wiring 21 and the individual wiring regions 25b of the plurality of individual wirings 25. In a plan view, the heating resistor 30 is arranged so as to intersect with the plurality of strip portions 22 and the plurality of individual wiring regions 25b. The heating resistor 30 is formed so as to straddle the plurality of strip portions 22 and the individual wiring regions 25b. Referring to FIG. 3 , the portions of the heating resistor 30 sandwiched between the strip portions 22 and the individual wiring regions 25b in the main scanning direction X are heating portions 31. The heating portions 31 are portions that generate heat when the heating resistor 30 is partially energized. The heat generated by the heating portions 31 prints on a print medium (e.g., thermal recording paper).

[0033] 2, the protective layer 33 protects the heating resistor 30. The protective layer 33 may further protect the common wiring 21 and the plurality of individual wirings 25. The protective layer 33 may be a laminate of a first protective layer 34 and a second protective layer 35.

[0034] The first protective layer 34 is formed on the heating resistor 30 and covers the heating resistor 30. The first protective layer 34 is formed on the common wiring 21 and the plurality of individual wirings 25 and may cover the common wiring 21 and the plurality of individual wirings 25. The first protective layer 34 may be formed on a part of the glaze 11 and a part of the planarizing layer 15. The first protective layer 34 is an insulating layer. The first protective layer 34 is formed of, for example, amorphous glass. The second protective layer 35 is formed on the first protective layer 34. The second protective layer 35 is formed of, for example, amorphous glass.

[0035] 1 and 2, the drive circuit 40 selectively energizes the plurality of individual wirings 25. The drive circuit 40 is, for example, a drive IC. In this embodiment, the plurality of drive circuits 40 are arranged spaced apart from one another in the main scanning direction X. The drive circuit 40 is arranged on the die bonding glaze 13. The drive circuit 40 is electrically connected to the individual wiring areas 25c of the plurality of individual wirings 25 and the second wirings 45. For example, the drive circuit 40 is electrically connected to the plurality of individual wiring areas 25b via conductive wires 41. The drive circuit 40 is electrically connected to the second wirings 45 via conductive wires (not shown).

[0036] 2, the sealing member 43 seals the drive circuit 40. The sealing member 43 has electrical insulating properties and is made of an insulating resin material such as epoxy resin.

[0037] 1, the plurality of second wirings 45 electrically connect the drive circuit 40 and the plurality of external connection terminals 50. The plurality of second wirings 45 are, for example, silver (Ag) wirings. The plurality of second wirings 45 are, for example, formed in the same manner as the second individual wiring portions 27.

[0038] 1, the plurality of external connection terminals 50 are terminals to which electric cables 60 are joined using a conductive joining member such as solder, or terminals to which connectors 61 are attached. The plurality of external connection terminals 50 are arranged along the outer periphery of the substrate 10 on the upstream side in the sub-scanning direction Y in a plan view of the main surface 10a. The plurality of external connection terminals 50 are electrically connected to the second wiring 45 and the detour portion 24 of the common wiring 21. The plurality of external connection terminals 50 are formed in the same manner as, for example, the second individual wiring portions 27.

[0039] The connector 61 can receive the electric cable 60. The connector 61 is attached to the plurality of external connection terminals 50. Control signals and the like are supplied to the drive circuit 40, the common wiring 21, and the like through the electric cable 60, the connector 61, and the plurality of external connection terminals 50. Note that if the electric cable 60 is joined to the plurality of external connection terminals 50 using a conductive joining member such as solder, the connector 61 is omitted.

[0040] An example of a method for manufacturing the thermal printhead of this embodiment will be described with reference to FIG.

[0041] A glaze 11 is formed on the main surface 10a of the substrate 10 (step S1). For example, the substrate 10 is prepared. A glass paste is printed on the main surface 10a of the substrate 10. The glass paste is fired. In this way, the glaze 11 is formed. The glaze 11 includes, for example, a heater glaze 12 and a die bonding glaze 13.

[0042] A planarization layer 15 is formed on the area of ​​the main surface 10a that is exposed from the glaze 11 (step S2). For example, a glass paste is printed on the area of ​​the main surface 10a that is exposed from the glaze 11. The glass paste is fired. In this way, the planarization layer 15 is formed. The planarization layer 15 includes, for example, a first planarization layer 16 and a second planarization layer 17.

[0043] Wiring (first wiring 20, second wiring 45), a plurality of external connection terminals 50, and a monitor pattern 65 are formed (step S3).

[0044] For example, a paste containing a conductive material such as gold (Au) particles is printed on the heater glaze 12 and the planarization layer 15. The paste is patterned by a photolithography process. The photolithography process includes a step of forming an etching mask by an exposure step and a development step, and a step of etching the paste using the etching mask. The patterned paste is then fired. In this way, the strip portion 22 of the common wiring 21 and the individual wiring regions 25b (first individual wiring portions 26) of the multiple individual wirings 25 are formed.

[0045] A resinate paste containing a conductive material such as silver (Ag) particles is printed on the planarizing layer 15, heater glaze 12, and die bonding glaze 13. A glass paste containing a conductive material such as silver (Ag) particles and glass frit is printed on a portion of the resinate paste. The resinate paste and glass paste are patterned using a photolithography process. The photolithography process includes a step of forming an etching mask using an exposure step and a development step, and a step of etching the resinate paste and glass paste using the etching mask. The patterned resinate paste and glass paste are fired. In this way, the connection portion 23 and detour portion 24 of the common wiring 21, the individual wiring regions 25a and 25c of the multiple individual wirings 25 (the first layer 28 and second layer 29 of the second individual wiring portion 27), the second wiring 45, the monitor pattern 65, and the multiple external connection terminals 50 are formed.

[0046] The monitor pattern 65 includes a plurality of strips 66. The width W2 (see FIGS. 4 to 7) of each of the plurality of strips 66 is equal to the width W1 (see FIGS. 4 to 7) of each of the individual wiring regions 25a of the plurality of individual wires 25. The spacing G2 (see FIG. 4) between adjacent strips 66 among the plurality of strips 66 is equal to the spacing G1 (see FIGS. 4 to 7) between adjacent individual wiring regions 25a among the individual wiring regions 25a of the plurality of individual wires 25.

[0047] The individual wiring region 25a of the multiple individual wirings 25 has the narrowest conductive layer width and the narrowest spacing between adjacent conductive layers among the first wirings 20, the second wirings 45, and the multiple external connection terminals 50. Therefore, the etching conditions for the individual wiring region 25a are the strictest among the first wirings 20, the second wirings 45, and the multiple external connection terminals 50. Therefore, a monitor pattern 65 is used to determine whether the etching conditions for the individual wiring region 25a are appropriate.

[0048] Specifically, the monitor pattern 65 is measured using a microscope or the like (step S4). Specifically, the width W2 of each of the multiple bands 66 and the interval G2 between adjacent bands 66 are measured.

[0049] The individual wiring areas 25a extend in a direction inclined with respect to the sub-scanning direction Y. Therefore, in order to directly measure the width W1 (see FIGS. 4 to 7) of the individual wiring areas 25a and the interval G1 (see FIGS. 4 to 7) between adjacent individual wiring areas 25a, it is necessary to rotate the substrate 10 on which the individual wiring areas 25a are formed before measuring the width W1 and the interval G1, so that the longitudinal direction of the individual wiring areas 25a is aligned with the sub-scanning direction Y before the substrate 10 is rotated.

[0050] In contrast, in this embodiment, the width W2 of the strip 66 (see FIGS. 4 to 7) is equal to the width W1 of the individual wiring region 25a. The spacing G2 between adjacent strips 66 (see FIGS. 4 to 7) is equal to the spacing G1 between adjacent individual wiring regions 25a (see FIGS. 4 to 7). Therefore, the width W1 and spacing G1 can be measured by measuring the width W2 and spacing G2. Furthermore, each of the multiple strips 66 extends in the sub-scanning direction Y. Therefore, the width W2 and spacing G2 can be measured without rotating the substrate 10. The width W2 and spacing G2 are equivalent to the width W1 and spacing G1, which are the basis for evaluating the etching conditions for the individual wiring region 25a.

[0051] In the monitor pattern 65, each of the bands 66 located at both ends in the main scanning direction X is adjacent to only one other band 66 in the main scanning direction X. Therefore, the bands 66 located at both ends in the main scanning direction X are more likely to be over-etched than the individual wiring region 25a. In contrast, the number of bands 66 adjacent to the central band 66c in the main scanning direction X is two. That is, there are bands 66 adjacent to the central band 66c on both sides of the central band 66c in the main scanning direction X. Furthermore, the central band 66c is farthest from the bands 66 located at both ends in the main scanning direction X. Therefore, monitoring the central band 66c is most appropriate for determining the etching conditions for the individual wiring region 25a.

[0052] The monitor pattern 65 includes a marker 67 that identifies the central band 66c. The marker 67 is used to identify the central band 66c. The width W2 of the central band 66c and the distance G2 between the central band 66c and its adjacent bands 66 are measured. This allows the etching conditions for the individual wiring region 25a to be monitored more efficiently.

[0053] Based on the width W2 of the strip 66 and the spacing G2 between adjacent strips 66, it is determined whether the etching conditions for the paste for forming the individual wiring region 25a are appropriate (step S5). For example, if the width W2 of the strip 66 measured in step S4 is within a first tolerance range and the spacing G2 between adjacent strips 66 measured in step S4 is within a second tolerance range, the etching conditions are determined to be appropriate, and the process proceeds to step S7. On the other hand, if the width W2 of the strip 66 measured in step S4 is not within the first tolerance range or the spacing G2 between adjacent strips 66 measured in step S4 is not within the second tolerance range, the etching conditions are determined to be inappropriate, and the process proceeds to a step of adjusting the etching conditions (step S6).

[0054] For example, if the width W2 of the strips 66 measured in step S4 is smaller than the minimum value of the first tolerance range, or if the spacing G2 of the strips 66 measured in step S4 is larger than the maximum value of the second tolerance range, the strips 66 and the individual wiring region 25a are over-etched. Therefore, the etching time for the individual wiring region 25a is shortened, or the concentration or composition of the etching solution for the individual wiring region 25a is changed. If the width W2 of the strips 66 measured in step S4 is larger than the maximum value of the first tolerance range, or if the spacing G2 of the strips 66 measured in step S4 is smaller than the minimum value of the second tolerance range, the strips 66 and the individual wiring region 25a are under-etched. Therefore, the etching time for the individual wiring region 25a is extended, or the concentration or composition of the etching solution for the individual wiring region 25a is changed. In this way, the etching conditions for the individual wiring region 25a are optimized.

[0055] Steps S1 to S6 are repeated until the etching conditions for the individual wiring region 25a become appropriate. In this way, under appropriate etching conditions, the connecting portion 23 and detour portion 24 of the common wiring 21, the individual wiring regions 25a, 25c (the first layer 28 and the second layer 29 of the second individual wiring portion 27) of the plurality of individual wirings 25, the second wiring 45, the monitor pattern 65, and the plurality of external connection terminals 50 are formed.

[0056] The heating resistor 30 is formed (step S7). For example, a resistor paste is applied to the heater glaze 12, the strip portions 22 of the common wiring 21, and the individual wiring regions 25b of the individual wirings 25. The resistor paste contains a conductive material, such as ruthenium oxide, tantalum nitride, tantalum, or silver-vanadium, and glass. The resistor paste is then fired. In this way, the heating resistor 30 is formed.

[0057] The protective layer 33 is formed (step S8). Specifically, glass paste is printed on the glaze 11, the planarizing layer 15, the first wiring 20, and the heating resistor 30. The glass paste is fired. In this way, the protective layer 33 is formed.

[0058] The laminate including the substrate 10, glaze 11, planarization layer 15, first wiring 20, monitor pattern 65, second wiring 45, multiple external connection terminals 50, heating resistor 30, and protective layer 33 is divided (step S9). For example, a cleaving groove is formed in the substrate 10 by laser scribing. The laminate is cleaved along the cleaving groove. In this way, the laminate is divided into individual pieces.

[0059] The drive circuit 40 is mounted on the die bonding glaze 13 (step S10). For example, the drive circuit 40 is fixed to the die bonding glaze 13 using a bonding member (not shown) such as a resin adhesive or solder.

[0060] Conductive wires are bonded (step S11). Conductive wires 41 are bonded to the drive circuit 40 and the individual wiring areas 25c of the plurality of individual wirings 25. Conductive wires (not shown) are bonded to the drive circuit 40 and the plurality of second wirings 45.

[0061] The drive circuit 40 is sealed with the sealing member 43 (step S12). For example, a sealing resin material is potted on the drive circuit 40. The sealing resin material is cured. In this way, the sealing member 43 is formed.

[0062] Connectors 61 are attached to the external connection terminals 50 (step S13). Note that if the electrical cable 60 is joined to the external connection terminals 50 using a conductive joining material such as solder, step S13 is omitted. In this way, the thermal printhead 1 is obtained.

[0063] Another example of the method for manufacturing the thermal printhead of this embodiment will be described with reference to Fig. 9. The other example of the manufacturing method shown in Fig. 9 includes the same steps as the example of the manufacturing method shown in Fig. 8, but differs from the example of the manufacturing method shown in Fig. 8 in that steps S3 to S6 are repeated until the etching conditions for the individual wiring region 25a become appropriate.

[0064] If it is determined in step S5 that the etching conditions are under-etching, the etching process of step S3 is further performed without returning to step S1. Steps S3 to S6 are repeated until the etching conditions become appropriate. The total etching time performed while repeating steps S3 to S6 is the etching time at which the etching conditions become appropriate. In this way, under appropriate etching conditions, the connection portion 23 and detour portion 24 of the common wiring 21, the individual wiring regions 25a and 25c of the multiple individual wirings 25, the second wiring 45, the monitor pattern 65, and the multiple external connection terminals 50 are formed.

[0065] The effects of the thermal printhead and the method for manufacturing the same according to this embodiment will now be described.

[0066] The thermal printhead 1 of this embodiment includes a plurality of individual wires 25 and a monitor pattern 65. Each of the plurality of individual wires 25 includes a first individual wiring region (individual wiring region 25a) extending in a direction inclined with respect to the sub-scanning direction Y. The monitor pattern 65 includes a plurality of strips 66. Each of the strips 66 extends in the sub-scanning direction Y. The strips 66 are arranged in the main scanning direction X and are formed of the same material as the first individual wiring region. The width W2 of each of the plurality of strips 66 is equal to the width W1 of each of the first individual wiring regions of the plurality of individual wires 25. The spacing G2 between adjacent strips 66 among the plurality of strips 66 is equal to the spacing G1 between adjacent first individual wiring regions among the first individual wiring regions of the plurality of individual wires 25.

[0067] Because the first individual wiring region (individual wiring region 25a) of the multiple individual wirings 25 extends in a direction inclined relative to the sub-scanning direction Y, the width W1 of the first individual wiring region and the interval G1 between adjacent first individual wiring regions are narrow. The etching conditions for the first individual wiring region are strict. However, the monitor pattern 65 includes multiple strips 66 extending in the sub-scanning direction Y. Therefore, the width W2 and the interval G2 can be measured without rotating the substrate 10. Furthermore, the width W2 of the strips 66 is equal to the width W1 of the first individual wiring region. The interval G2 between adjacent strips 66 is equal to the interval G1 between adjacent first individual wiring regions. The width W2 and the interval G2 are equivalent to the width W1 and the interval G1, which are the basis for evaluating strict etching conditions. In this way, the etching conditions for the first individual wiring region can be efficiently monitored.

[0068] In the thermal printhead 1 of this embodiment, the first individual wiring region (individual wiring region 25a) of the plurality of individual wirings 25 is the portion of the plurality of individual wirings 25 that is most inclined with respect to the sub-scanning direction Y.

[0069] The etching conditions for the portion of the multiple individual wirings 25 that is most inclined with respect to the sub-scanning direction Y are the most severe. In this embodiment, the width W2 and the spacing G2 can be measured without rotating the substrate 10. The width W2 and the spacing G2 are equivalent to the width W1 and the spacing G1 that form the basis for evaluating the most severe etching conditions. In this way, the etching conditions for the first individual wiring region (individual wiring region 25a) can be efficiently monitored.

[0070] The thermal printhead 1 of this embodiment further includes a substrate 10, a heater glaze 12, a heating resistor 30, and a planarization layer (first planarization layer 16). The substrate 10 has a main surface 10a extending along the main scanning direction X and the sub-scanning direction Y. The heater glaze 12 is disposed on the main surface 10a. The heating resistor 30 is disposed on the heater glaze 12. The planarization layer is disposed on the main surface 10a. A first thickness of the planarization layer is smaller than a second thickness of the heater glaze 12. Each of the multiple individual wirings 25 includes a second individual wiring region (individual wiring region 25b). The second individual wiring region is connected to the first individual wiring region (individual wiring region 25a), extends in the sub-scanning direction Y, is disposed on the heater glaze 12, and is electrically connected to the heating resistor 30. The first individual wiring region of the multiple individual wirings 25 and the monitor pattern 65 are disposed on the planarization layer.

[0071] The first thickness of the planarization layer (first planarization layer 16) is different from the second thickness of the heater glaze 12. Therefore, the thickness of the paste containing the conductive material on the planarization layer may be different from the thickness of the paste containing the conductive material on the heater glaze 12. The thickness of the portion of the etching mask for the multiple individual wirings 25 above the planarization layer may be different from the thickness of the portion of the etching mask for the multiple individual wirings 25 above the planarization layer. The exposure conditions for the portion of the etching mask for the multiple individual wirings 25 above the planarization layer may be different from the exposure conditions for the portion of the etching mask for the multiple individual wirings 25 above the planarization layer. The exposure conditions are, for example, the proximity gap in the proximity exposure process. Furthermore, if the material of the planarization layer is different from the material of the heater glaze 12, the etching rate of the paste containing the conductive material on the planarization layer may be different from the etching rate of the paste containing the conductive material on the heater glaze 12. Therefore, the etching conditions for the first individual wiring region (individual wiring region 25a) are stricter.

[0072] However, the monitor pattern 65 includes multiple strips 66 extending in the sub-scanning direction Y. Therefore, the width W2 and the spacing G2 can be measured without rotating the substrate 10. The width W2 and the spacing G2 are equivalent to the width W1 and the spacing G1 that form the basis for evaluating strict etching conditions. In this way, the etching conditions of the first individual wiring region (individual wiring region 25a) can be efficiently monitored.

[0073] The thermal printhead 1 of this embodiment further includes a die bonding glaze 13 and a drive circuit 40. The die bonding glaze 13 is disposed on the main surface 10a. The drive circuit 40 is disposed on the die bonding glaze 13. The first thickness of the planarization layer (first planarization layer 16) is smaller than the third thickness of the die bonding glaze 13. Each of the multiple individual wirings 25 includes a third individual wiring area (individual wiring area 25c). The third individual wiring area is connected to the first individual wiring area (individual wiring area 25a), disposed on the die bonding glaze 13, and electrically connected to the drive circuit 40.

[0074] The first thickness of the planarization layer (first planarization layer 16) is different from the third thickness of the die bonding glaze 13. Therefore, the thickness of the paste containing the conductive material on the planarization layer may be different from the thickness of the paste containing the conductive material on the die bonding glaze 13. The thickness of the portion of the etching mask for the multiple individual wirings 25 above the planarization layer may be different from the thickness of the portion of the etching mask for the multiple individual wirings 25 above the planarization layer. The exposure conditions for the portion of the etching mask for the multiple individual wirings 25 above the planarization layer may be different from the exposure conditions for the portion of the etching mask for the multiple individual wirings 25 above the planarization layer. The exposure conditions are, for example, a proximity gap in a proximity exposure process. Furthermore, if the material of the planarization layer is different from the material of the die bonding glaze 13, the etching rate of the paste containing the conductive material on the planarization layer may be different from the etching rate of the paste containing the conductive material on the die bonding glaze 13. Therefore, the etching conditions for the first individual wiring region (individual wiring region 25a) become stricter.

[0075] However, the monitor pattern 65 includes multiple strips 66 extending in the sub-scanning direction Y. Therefore, the width W2 and the spacing G2 can be measured without rotating the substrate 10. The width W2 and the spacing G2 are equivalent to the width W1 and the spacing G1 that form the basis for evaluating strict etching conditions. In this way, the etching conditions of the first individual wiring region (individual wiring region 25a) can be efficiently monitored.

[0076] In the thermal printhead 1 of this embodiment, the monitor pattern 65 includes a central band 66c that is located in the center of the multiple bands 66 in the main scanning direction X. The width W2 is the width of the central band 66c. The spacing G2 is the spacing between the central band 66c and the band 66 adjacent to the central band 66c.

[0077] In the monitor pattern 65, each of the bands 66 located at both ends in the main scanning direction X is adjacent to only one band 66 in the main scanning direction X. Therefore, the bands 66 located at both ends in the main scanning direction X are more likely to be over-etched than the individual wiring region 25a. In contrast, the number of bands 66 adjacent to the central band 66c in the main scanning direction X is two. That is, there are bands 66 adjacent to the central band 66c on both sides of the central band 66c in the main scanning direction X. Furthermore, the central band 66c is farthest from the bands 66 located at both ends in the main scanning direction X. Therefore, monitoring the central band 66c is most appropriate for determining the etching conditions for the individual wiring region 25a. This allows for more accurate monitoring of the etching conditions for the first individual wiring region (individual wiring region 25a).

[0078] In the thermal printhead 1 of this embodiment, the monitor pattern 65 includes a marker 67 that identifies the central band 66c.

[0079] The central strip 66c to be monitored can be easily identified by the marker 67. The etching conditions for the first individual wiring region (individual wiring region 25a) can be monitored efficiently.

[0080] The method for manufacturing the thermal printhead 1 of this embodiment includes a step (step S3) of forming a plurality of individual wirings 25 and a monitor pattern 65 by etching a paste containing a conductive material. The monitor pattern 65 includes a plurality of strip-shaped bodies 66. The method for manufacturing the thermal printhead 1 of this embodiment also includes a step (step S4) of measuring the width W2 of each of the plurality of strip-shaped bodies 66 and the spacing G2 between adjacent strip-shaped bodies 66, and a step (step S5) of determining whether the etching conditions for the paste are appropriate based on the width W2 and spacing G2. Each of the plurality of individual wirings 25 includes a first individual wiring region (individual wiring region 25a) extending in a direction inclined with respect to the sub-scanning direction Y. Each of the plurality of strip-shaped bodies 66 extends in the sub-scanning direction Y. The plurality of strip-shaped bodies 66 are arranged in the main scanning direction X and are formed of the same material as the first individual wiring region. The width W2 of each of the multiple strips 66 is equal to the width W1 of each of the first individual wiring regions of the multiple individual wirings 25. The spacing G2 between adjacent strips 66 among the multiple strips 66 is equal to the spacing G1 between adjacent first individual wiring regions among the first individual wiring regions of the multiple individual wirings 25.

[0081] Because the first individual wiring region (individual wiring region 25a) of the multiple individual wirings 25 extends in a direction inclined relative to the sub-scanning direction Y, the width W1 of the first individual wiring region and the interval G1 between adjacent first individual wiring regions are narrow. The etching conditions for the first individual wiring region are strict. However, the monitor pattern 65 includes multiple strips 66 extending in the sub-scanning direction Y. Therefore, the width W2 and the interval G2 can be measured without rotating the substrate 10. Furthermore, the width W2 of the strips 66 is equal to the width W1 of the first individual wiring region. The interval G2 between adjacent strips 66 is equal to the interval G1 between adjacent first individual wiring regions. The width W2 and the interval G2 are equivalent to the width W1 and the interval G1, which are the basis for evaluating strict etching conditions. In this way, the etching conditions for the first individual wiring region can be efficiently monitored.

[0082] In the method for manufacturing the thermal printhead 1 of this embodiment, the first individual wiring region (individual wiring region 25a) of the plurality of individual wirings 25 is the portion of the plurality of individual wirings 25 that is most inclined with respect to the sub-scanning direction Y.

[0083] The etching conditions for the portion of the multiple individual wirings 25 that is most inclined with respect to the sub-scanning direction Y are the most severe. In this embodiment, the width W2 and the spacing G2 can be measured without rotating the substrate 10. The width W2 and the spacing G2 are equivalent to the width W1 and the spacing G1 that form the basis for evaluating the most severe etching conditions. In this way, the etching conditions for the first individual wiring region (individual wiring region 25a) can be efficiently monitored.

[0084] The method for manufacturing the thermal printhead 1 of this embodiment further includes the steps of forming a heater glaze 12 on the main surface 10a of the substrate 10 (step S1), forming a planarization layer (first planarization layer 16) on the main surface 10a (step S2), and forming a heating resistor 30 on the heater glaze 12 (step S7). The main surface 10a extends along the main scanning direction X and the sub-scanning direction Y. The first thickness of the planarization layer is smaller than the second thickness of the heater glaze 12. Each of the multiple individual wirings 25 includes a second individual wiring region (individual wiring region 25b). The second individual wiring region is connected to the first individual wiring region (individual wiring region 25a), extends in the sub-scanning direction Y, is disposed on the heater glaze 12, and is electrically connected to the heating resistor 30. The first individual wiring region of the multiple individual wirings 25 and the monitor pattern 65 are formed on the planarization layer.

[0085] The first thickness of the planarization layer (first planarization layer 16) is different from the second thickness of the heater glaze 12. Therefore, the thickness of the paste containing the conductive material on the planarization layer may be different from the thickness of the paste containing the conductive material on the heater glaze 12. The thickness of the portion of the etching mask for the multiple individual wirings 25 above the planarization layer may be different from the thickness of the portion of the etching mask for the multiple individual wirings 25 above the planarization layer. The exposure conditions for the portion of the etching mask for the multiple individual wirings 25 above the planarization layer may be different from the exposure conditions for the portion of the etching mask for the multiple individual wirings 25 above the planarization layer. The exposure conditions are, for example, the proximity gap in the proximity exposure process. Furthermore, if the material of the planarization layer is different from the material of the heater glaze 12, the etching rate of the paste containing the conductive material on the planarization layer may be different from the etching rate of the paste containing the conductive material on the heater glaze 12. Therefore, the etching conditions for the first individual wiring region (individual wiring region 25a) are stricter.

[0086] However, the monitor pattern 65 includes multiple strips 66 extending in the sub-scanning direction Y. Therefore, the width W2 and the spacing G2 can be measured without rotating the substrate 10. The width W2 and the spacing G2 are equivalent to the width W1 and the spacing G1 that form the basis for evaluating strict etching conditions. In this way, the etching conditions of the first individual wiring region (individual wiring region 25a) can be efficiently monitored.

[0087] The method for manufacturing the thermal printhead 1 of this embodiment further includes the steps of forming a die bonding glaze 13 on the main surface 10a (step S1) and providing a drive circuit 40 on the die bonding glaze 13 (step S10). The first thickness of the planarization layer (first planarization layer 16) is smaller than the third thickness of the die bonding glaze 13. Each of the multiple individual wirings 25 includes a third individual wiring region (individual wiring region 25c). The third individual wiring region is connected to the first individual wiring region (individual wiring region 25a), is disposed on the die bonding glaze 13, and is electrically connected to the drive circuit 40.

[0088] The first thickness of the planarization layer (first planarization layer 16) is different from the third thickness of the die bonding glaze 13. Therefore, the thickness of the paste containing the conductive material on the planarization layer may be different from the thickness of the paste containing the conductive material on the die bonding glaze 13. The thickness of the portion of the etching mask for the multiple individual wirings 25 above the planarization layer may be different from the thickness of the portion of the etching mask for the multiple individual wirings 25 above the planarization layer. The exposure conditions for the portion of the etching mask for the multiple individual wirings 25 above the planarization layer may be different from the exposure conditions for the portion of the etching mask for the multiple individual wirings 25 above the planarization layer. The exposure conditions are, for example, a proximity gap in a proximity exposure process. Furthermore, if the material of the planarization layer is different from the material of the die bonding glaze 13, the etching rate of the paste containing the conductive material on the planarization layer may be different from the etching rate of the paste containing the conductive material on the die bonding glaze 13. Therefore, the etching conditions for the first individual wiring region (individual wiring region 25a) become stricter.

[0089] However, the monitor pattern 65 includes multiple strips 66 extending in the sub-scanning direction Y. Therefore, the width W2 and the spacing G2 can be measured without rotating the substrate 10. The width W2 and the spacing G2 are equivalent to the width W1 and the spacing G1 that form the basis for evaluating strict etching conditions. In this way, the etching conditions of the first individual wiring region (individual wiring region 25a) can be efficiently monitored.

[0090] In the manufacturing method of the thermal printhead 1 of this embodiment, the monitor pattern 65 includes a central band 66c that is central in the main scanning direction X among the multiple bands 66. The width W2 is the width of the central band 66c. The spacing G2 is the spacing between the central band 66c and the band 66 adjacent to the central band 66c.

[0091] In the monitor pattern 65, each of the bands 66 located at both ends in the main scanning direction X is adjacent to only one band 66 in the main scanning direction X. Therefore, the bands 66 located at both ends in the main scanning direction X are more likely to be over-etched than the individual wiring region 25a. In contrast, the number of bands 66 adjacent to the central band 66c in the main scanning direction X is two. That is, there are bands 66 adjacent to the central band 66c on both sides of the central band 66c in the main scanning direction X. Furthermore, the central band 66c is farthest from the bands 66 located at both ends in the main scanning direction X. Therefore, monitoring the central band 66c is most appropriate for determining the etching conditions for the individual wiring region 25a. This allows for more accurate monitoring of the etching conditions for the first individual wiring region (individual wiring region 25a).

[0092] In the method for manufacturing the thermal printhead 1 of this embodiment, the monitor pattern 65 includes a marker 67 that identifies the central band 66c.

[0093] The central strip 66c to be monitored can be easily identified by the marker 67. The etching conditions for the first individual wiring region (individual wiring region 25a) can be monitored efficiently.

[0094] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) Multiple individual wiring and monitor pattern, each of the plurality of individual wirings includes a first individual wiring region extending in a direction inclined with respect to the sub-scanning direction; the monitor pattern includes a plurality of bands; Each of the plurality of bands extends in the sub-scanning direction, the plurality of strips are arranged in a main scanning direction and are made of the same material as the first individual wiring region; a width of each of the plurality of strips is equal to a width of each of the first individual wiring regions of the plurality of individual wirings; A thermal printhead, wherein the spacing between adjacent bands among the plurality of bands is equal to the spacing between adjacent first individual wiring regions among the first individual wiring regions of the plurality of individual wirings. (Appendix 2) 2. The thermal printhead according to claim 1, wherein the first individual wiring region of the plurality of individual wirings is a portion of the plurality of individual wirings that is most inclined with respect to the sub-scanning direction. (Appendix 3) a substrate having a main surface extending along the main scanning direction and the sub-scanning direction; a heater glaze disposed on the major surface; a heating resistor disposed on the heater glaze; a planarization layer disposed on the major surface, the first thickness of the planarization layer is less than the second thickness of the heater glaze; each of the plurality of individual wirings includes a second individual wiring region; the second individual wiring area is connected to the first individual wiring area, extends in the sub-scanning direction, is disposed on the heater glaze, and is electrically connected to the heating resistor; 3. The thermal printhead according to claim 1, wherein the first individual wiring region of the plurality of individual wirings and the monitor pattern are disposed on the planarization layer. (Appendix 4) a die bonding glaze disposed on the main surface; a driving circuit disposed on the die bonding glaze; the first thickness of the planarization layer is less than a third thickness of the die bonding glaze; each of the plurality of individual wirings includes a third individual wiring region; 4. The thermal printhead of claim 3, wherein the third individual wiring area is connected to the first individual wiring area, is disposed on the die bonding glaze, and is electrically connected to the drive circuit. (Appendix 5) the monitor pattern includes a central band that is central in the main scanning direction among the plurality of bands, the width is the width of the central band; 5. The method for manufacturing a thermal printhead according to claim 1, wherein the spacing is the spacing between the central band and a band adjacent to the central band. (Appendix 6) 6. The thermal printhead of claim 5, wherein the monitor pattern includes a marker identifying the central band. (Appendix 7) forming a plurality of individual wirings and a monitor pattern by etching a paste containing a conductive material, the monitor pattern including a plurality of strips; measuring a width of each of the plurality of bands and a spacing between adjacent bands of the plurality of bands; determining whether the etching conditions of the paste are appropriate based on the width and the interval; each of the plurality of individual wirings includes a first individual wiring region extending in a direction inclined with respect to the sub-scanning direction; Each of the plurality of bands extends in the sub-scanning direction, the plurality of strips are arranged in a main scanning direction and are made of the same material as the first individual wiring region; a width of each of the plurality of strips is equal to a width of each of the first individual wiring regions of the plurality of individual wirings; A method for manufacturing a thermal printhead, wherein the spacing between adjacent bands among the plurality of bands is equal to the spacing between adjacent first individual wiring regions among the first individual wiring regions of the plurality of individual wirings. (Appendix 8) 8. The method for manufacturing a thermal printhead according to claim 7, wherein the first individual wiring region of the plurality of individual wirings is the portion of the plurality of individual wirings that is most inclined with respect to the sub-scanning direction. (Appendix 9) forming a heater glaze on a major surface of the substrate; forming a planarization layer on the major surface; forming a heating resistor on the heater glaze; the main surface extends along the main scanning direction and the sub-scanning direction, the first thickness of the planarization layer is less than the second thickness of the heater glaze; each of the plurality of individual wirings includes a second individual wiring region; the second individual wiring area is connected to the first individual wiring area, extends in the sub-scanning direction, is disposed on the heater glaze, and is electrically connected to the heating resistor; 9. The method for manufacturing a thermal printhead according to claim 7, wherein the first individual wiring region of the plurality of individual wirings and the monitor pattern are formed on the planarization layer. (Appendix 10) forming a die bonding glaze on the major surface; and providing a driving circuit on the die bonding glaze; the first thickness of the planarization layer is less than a third thickness of the die bonding glaze; each of the plurality of individual wirings includes a third individual wiring region; 10. A method for manufacturing a thermal printhead as described in Appendix 9, wherein the third individual wiring area is connected to the first individual wiring area, is disposed on the die bonding glaze, and is electrically connected to the drive circuit. (Appendix 11) the monitor pattern includes a central band that is central in the main scanning direction among the plurality of bands, the width is the width of the central band; 11. The method for manufacturing a thermal printhead according to claim 7, wherein the spacing is the spacing between the central band and a band adjacent to the central band. (Appendix 12) 12. A method for manufacturing a thermal printhead according to claim 11, wherein the monitor pattern includes a marker that identifies the central band.

[0095] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0096] 1 thermal print head, 10 substrate, 10a main surface, 11 glaze, 12 heater glaze, 13 die bonding glaze, 15 planarization layer, 16 first planarization layer, 17 second planarization layer, 20 first wiring, 21 common wiring, 22 strip portion, 23 connecting portion, 24 detouring portion, 25 individual wiring, 25a, 25b, 25c individual wiring area, 26 first individual wiring portion, 27 second individual wiring portion, 28 first layer, 29 second layer, 30 heating resistor, 31 heating portion, 33 protective layer, 34 first protective layer, 35 second protective layer, 40 drive circuit, 41 conductive wire, 43 sealing member, 45 second wiring, 50 external connection terminal, 60 electric cable, 61 connector, 65 monitor pattern, 66 strip, 66c central strip, 67 Marker.

Claims

1. Multiple individual wiring and monitor pattern, each of the plurality of individual wirings includes a first individual wiring region extending in a direction inclined with respect to the sub-scanning direction; the monitor pattern includes a plurality of bands; Each of the plurality of bands extends in the sub-scanning direction, the plurality of strips are arranged in a main scanning direction and are made of the same material as the first individual wiring region; a width of each of the plurality of strips is equal to a width of each of the first individual wiring regions of the plurality of individual wirings; A thermal printhead, wherein the spacing between adjacent bands of the plurality of bands is equal to the spacing between adjacent first individual wiring regions of the plurality of individual wirings.

2. 2. The thermal printhead according to claim 1, wherein the first individual wiring region of the plurality of individual wirings is a portion of the plurality of individual wirings that is most inclined with respect to the sub-scanning direction.

3. a substrate having a main surface extending along the main scanning direction and the sub-scanning direction; a heater glaze disposed on the major surface; a heating resistor disposed on the heater glaze; a planarization layer disposed on the major surface, the first thickness of the planarization layer is less than the second thickness of the heater glaze; each of the plurality of individual wirings includes a second individual wiring region; the second individual wiring area is connected to the first individual wiring area, extends in the sub-scanning direction, is disposed on the heater glaze, and is electrically connected to the heating resistor; 3. The thermal printhead according to claim 1, wherein the first individual wiring region of the plurality of individual wirings and the monitor pattern are disposed on the planarization layer.

4. a die bonding glaze disposed on the main surface; a driving circuit disposed on the die bonding glaze; the first thickness of the planarization layer is less than a third thickness of the die bonding glaze; each of the plurality of individual wirings includes a third individual wiring region; 4. The thermal printhead according to claim 3, wherein the third individual wiring area is connected to the first individual wiring area, is disposed on the die bonding glaze, and is electrically connected to the drive circuit.

5. the monitor pattern includes a central band that is central in the main scanning direction among the plurality of bands, the width is the width of the central band; 3. The method for manufacturing a thermal printhead according to claim 1, wherein the spacing is the spacing between the central band and a band adjacent to the central band.

6. The thermal printhead of claim 5 , wherein the monitor pattern includes a marker that identifies the central band.

7. forming a plurality of individual wirings and a monitor pattern by etching a paste containing a conductive material, the monitor pattern including a plurality of strips; measuring a width of each of the plurality of bands and a spacing between adjacent bands of the plurality of bands; determining whether the etching conditions of the paste are appropriate based on the width and the interval; each of the plurality of individual wirings includes a first individual wiring region extending in a direction inclined with respect to the sub-scanning direction; Each of the plurality of bands extends in the sub-scanning direction, the plurality of strips are arranged in a main scanning direction and are made of the same material as the first individual wiring region; a width of each of the plurality of strips is equal to a width of each of the first individual wiring regions of the plurality of individual wirings; A method for manufacturing a thermal printhead, wherein the spacing between adjacent bands among the plurality of bands is equal to the spacing between adjacent first individual wiring regions among the first individual wiring regions of the plurality of individual wirings.

8. The method for manufacturing a thermal printhead according to claim 7 , wherein the first individual wiring region of the plurality of individual wirings is a portion of the plurality of individual wirings that is most inclined with respect to the sub-scanning direction.

9. forming a heater glaze on a major surface of the substrate; forming a planarization layer on the major surface; forming a heating resistor on the heater glaze; the main surface extends along the main scanning direction and the sub-scanning direction, the first thickness of the planarization layer is less than the second thickness of the heater glaze; each of the plurality of individual wirings includes a second individual wiring region; the second individual wiring area is connected to the first individual wiring area, extends in the sub-scanning direction, is disposed on the heater glaze, and is electrically connected to the heating resistor; 9. The method for manufacturing a thermal printhead according to claim 7, wherein the first individual wiring region of the plurality of individual wirings and the monitor pattern are formed on the planarization layer.

10. forming a die bonding glaze on the major surface; and providing a driving circuit on the die bonding glaze; the first thickness of the planarization layer is less than a third thickness of the die bonding glaze; each of the plurality of individual wirings includes a third individual wiring region; 10. The method for manufacturing a thermal printhead according to claim 9, wherein the third individual wiring area is connected to the first individual wiring area, is disposed on the die bonding glaze, and is electrically connected to the drive circuit.

11. the monitor pattern includes a central band that is central in the main scanning direction among the plurality of bands, the width is the width of the central band; 9. The method for manufacturing a thermal printhead according to claim 7, wherein the gap is the gap between the central band and a band adjacent to the central band.

12. The method for manufacturing a thermal printhead according to claim 11 , wherein the monitor pattern includes a marker that identifies the central band.

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