Thermal printhead, method of manufacturing a thermal printhead, and thermal printer

Abstract

The present application provides a thermal print head capable of improving the printing energy efficiency, a manufacturing method thereof, and a thermal printer provided with the thermal print head. The thermal print head (A10) of the present application is provided with: a substrate (1) having a convex surface (12); a resistance layer (3) containing a plurality of heating portions and containing a portion formed on the convex surface (12); and a wiring layer (4) in conduction with the plurality of heating portions. The thermal print head (A10) is further provided with a glaze layer (21) having a pair of end edges (211) arranged separately from each other in the y direction and formed in contact with a top surface (121) of the convex surface (12). The plurality of heating portions (31) are formed on the glaze layer (21). When viewed in the z direction, the pair of end edges (211) each contain a retreat interval (211A) located inward of the top surface (121) from a boundary (123) between the top surface (121) and a pair of inclined surfaces (122) of the convex surface (12).

Description

TECHNICAL FIELD

[0001] The present application relates to a thermal printhead and a manufacturing method thereof, and a thermal printer provided with the thermal printhead. BACKGROUND

[0002] A thermal printhead is disclosed in Patent Literature 1, which uses silicon in a substrate material thereof. In the thermal printhead disclosed in this document, a substrate has a main face, and a protruding portion extending in a main scanning direction and protruding from the main face. As shown in FIG. 1 of this document, a plurality of heat generating portions are arranged on the protruding portion in the main scanning direction. According to this configuration, it is possible to make a print medium surely contact the protruding portion on which the plurality of heat generating portions are arranged, and thus an improvement in print quality can be expected. On the other hand, there is a strong demand in the industry for improving print energy efficiency. Figure 6 [Patent Literature 1] Japanese Patent Application Laid-Open No. 2019-166824

[0003] [BACKGROUND ART DOCUMENT]

[0004] [Patent Literature]

[0005] [Patent Literature 1] Japanese Patent Application Laid-Open No. 2019-166824 SUMMARY

[0006] [PROBLEMS TO BE SOLVED BY THE INVENTION]

[0007] The present application, in view of the circumstances, will provide a thermal printhead and a manufacturing method thereof capable of improving print energy efficiency, and a thermal printer provided with the thermal printhead, as a problem to be solved by the present application.

[0008] [TECHNICAL MEANS FOR SOLVING THE PROBLEMS]

[0009] The thermal printhead provided by the first aspect of the present application is characterized by including: a substrate having a main face facing in a thickness direction, and a convex face connected to the main face and protruding in the thickness direction toward a side on which the main face faces; a resistance layer including a plurality of heat generating portions arranged in a main scanning direction, and formed on the main face and the convex face; and a wiring layer formed in grounding with the resistance layer and in conduction with the plurality of heat generating portions; and the convex face includes a top face parallel to the main face, and a pair of inclined faces connected to the top face and the main face and arranged apart from each other in a sub scanning direction, the thermal printhead further including a glaze layer having a pair of end edges arranged apart from each other in the sub scanning direction and formed in grounding with the top face, the plurality of heat generating portions being formed on the glaze layer, the pair of end edges each including a retreat interval on an inner side of the top face than an intersection of the top face and the pair of inclined faces, as viewed in the thickness direction.

[0010] The manufacturing method of the thermal head according to the second aspect of the present application is characterized by comprising the steps of: forming a main surface facing in a thickness direction and a convex surface connected to the main surface and protruding in the thickness direction toward one side of the main surface facing; forming a resistance layer on the main surface and the convex surface, the resistance layer including a plurality of heat generating portions arranged in a main scanning direction; and forming a wiring layer in conduction with the plurality of heat generating portions in contact with the resistance layer; and the convex surface including a top surface parallel to the main surface and a pair of inclined surfaces connected to the top surface and the main surface and arranged apart from each other in a sub scanning direction, the manufacturing method further comprising the step of forming a glaze layer in contact with the top surface between the step of forming the main surface and the convex surface and the step of forming the resistance layer, in the step of forming the glaze layer, a glaze material is supplied as a fluid to the top surface, and the glaze material is fired, thereby forming the glaze layer.

[0011] The thermal printer according to the third aspect of the present application includes the thermal head according to the first aspect of the present application and a platen arranged opposite the plurality of heat generating portions.

[0012] [Effects of Invention]

[0013] According to the thermal head and the manufacturing method thereof, it is possible to improve the printing energy efficiency.

[0014] Other features and advantages of the present application will be more apparent from the following detailed description, based on the attached drawings. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a plan view of the thermal head according to the first embodiment of the present application, and a protective layer is transparent.

[0016] Figure 2 is a plan view of the thermal head according to the first embodiment of the present application, and a protective layer is transparent. Figure 1 is a plan view of the thermal head according to the first embodiment of the present application, and a protective layer is transparent.

[0017] Figure 3 is a plan view of the thermal head according to the first embodiment of the present application, and a protective layer is transparent. Figure 2 is a plan view of the thermal head according to the first embodiment of the present application, and a protective layer is transparent.

[0018] Figure 4 is a plan view of the thermal head according to the first embodiment of the present application, and a protective layer is transparent. Figure 1 is a plan view of the thermal head according to the first embodiment of the present application, and a protective layer is transparent.

[0019] Figure 5 is a plan view of the thermal head according to the first embodiment of the present application, and a protective layer is transparent. Figure 1 is a plan view of the thermal head according to the first embodiment of the present application, and a protective layer is transparent.

[0020] Figure 6 is a plan view of the thermal head according to the first embodiment of the present application, and a protective layer is transparent. Figure 5 is a plan view of the thermal head according to the first embodiment of the present application, and a protective layer is transparent.

[0021] Figure 7 is a plan view of the thermal head according to the first embodiment of the present application, and a protective layer is transparent.Figure 3 A partial enlarged view, showing the insulating layer, resistor layer and wiring layer.

[0022] Figure 8 yes Figure 3 A partial enlarged view, showing the insulating layer, resistor layer and wiring layer.

[0023] Figure 9 It is along Figure 7 and Figure 8 A cross-sectional view taken along line IX-IX.

[0024] Figure 10 yes Figure 1 A partially enlarged cross-sectional view of a variation of the thermal print head shown.

[0025] Figure 11 Yes Figure 1 The following are cross-sectional views illustrating the manufacturing process of the main parts of the thermal print head.

[0026] Figure 12 Yes Figure 1 The following are cross-sectional views illustrating the manufacturing process of the main parts of the thermal print head.

[0027] Figure 13 Yes Figure 1 The following are cross-sectional views illustrating the manufacturing process of the main parts of the thermal print head.

[0028] Figure 14 is with Figure 13 The sectional view corresponds to the partially enlarged top view.

[0029] Figure 15 It is along Figure 14 Cross-sectional view along line XV-XV.

[0030] Figure 16 Yes Figure 1 The following are cross-sectional views illustrating the manufacturing process of the main parts of the thermal print head.

[0031] Figure 17 Yes Figure 1 The following are cross-sectional views illustrating the manufacturing process of the main parts of the thermal print head.

[0032] Figure 18 Yes Figure 1 The following are cross-sectional views illustrating the manufacturing process of the main parts of the thermal print head.

[0033] Figure 19 Yes Figure 1 The following are cross-sectional views illustrating the manufacturing process of the main parts of the thermal print head.

[0034] Figure 20Yes Figure 1 The following are cross-sectional views illustrating the manufacturing process of the main parts of the thermal print head.

[0035] Figure 21 Yes Figure 1 The following are cross-sectional views illustrating the manufacturing process of the main parts of the thermal print head.

[0036] Figure 22 Yes Figure 1 The following are cross-sectional views illustrating the manufacturing process of the main parts of the thermal print head.

[0037] Figure 23 It is a cross-sectional view of a main portion of a thermal print head according to a second embodiment of the present invention.

[0038] Figure 24 yes Figure 23 A partial enlarged view of . DETAILED DESCRIPTION

[0039] Modes for carrying out the present invention will be described with reference to the drawings.

[0040] [First embodiment]

[0041] based on Figures 1-10 The thermal print head A10 according to the first embodiment of the present invention is described. The thermal print head A10 constitutes the main part of the thermal printer B10 described below. The thermal print head A10 is composed of a main part and ancillary parts. The main part of the thermal print head A10 includes a substrate 1, a glaze layer 21, an insulating layer 22, a resistor layer 3, a wiring layer 4, and a protective layer 5. The ancillary parts of the thermal print head A10 include a wiring substrate 71, a heat sink 72, a plurality of driving elements 73, a plurality of first wires 74, a plurality of second wires 75, a sealing resin 76, and a connector 77. Here, in Figure 1 In the figure, for ease of understanding, the protective layer 5 is shown through, and the first conductive wires 74, the second conductive wires 75, and the sealing resin 76 are omitted. Figure 2 and Figure 3 In order to facilitate understanding, the protective layer 5 is shown. Figure 7 and Figure 8 For ease of understanding, relative to Figure 3 Furthermore, it passes through the insulating layer 22 , the resistor layer 3 , and the wiring layer 4 . Figure 10 The cross-sectional position and size of Figure 6 The cross-sectional position and size are the same.

[0042] For ease of explanation, the main scanning direction of the thermal print head A10 is referred to as the "x-direction." The secondary scanning direction of the thermal print head A10 is referred to as the "y-direction." The thickness direction of the substrate 1 is referred to as the "z-direction." The z-direction is orthogonal to both the x-direction and the y-direction. In the following description, "viewed along the z-direction" means "viewed along the thickness direction."

[0043] Thermal print head A10, such as Figure 4 As shown, the substrate 1 constituting the main part of the thermal print head A10 is bonded to the heat sink 72. Furthermore, the wiring substrate 71 is located next to the substrate 1 in the y direction. Like the substrate 1, the wiring substrate 71 is fixed to the heat sink 72. A plurality of heating portions 31 (details will be described below) are formed on the substrate 1. These heating portions 31 constitute a part of the resistance layer 3 and are arranged in the x direction. The plurality of heating portions 31 selectively generate heat through a plurality of driving elements 73 mounted on the wiring substrate 71. The plurality of driving elements 73 are driven according to a printing signal sent from the outside via the connector 77.

[0044] Furthermore, if Figure 4 As shown, the thermal printer B10 of the present invention has a thermal print head A10 and a platen roller 79. In the thermal printer B10, the platen roller 79 is a roller-shaped mechanism that feeds out recording media such as thermal paper. The platen roller 79 presses the recording medium against the multiple heating parts 31, whereby the multiple heating parts 31 print on the recording medium. In the thermal printer B10, a non-roller-shaped mechanism can be used instead of the platen roller 79. The mechanism has a flat surface. Here, the flat surface includes a curved surface with a small curvature. In the thermal printer B10, the roller-shaped mechanism such as the platen roller 79 and related mechanisms are referred to as a "stamping member". Here, for the sake of convenience, Figure 4 The recording medium supply source side ( Figure 4 The right side of the image is called the "upstream side". Figure 4 The recording medium discharge destination side ( Figure 4 The left side of the diagram is called the "downstream side".

[0045] like Figure 1 As shown, the substrate 1 is in the shape of a strip extending in the x direction when viewed in the z direction. The substrate 1 comprises a semiconductor material. The semiconductor material comprises a single crystal material having silicon (Si) as a component.

[0046] like Figure 5 As shown, the substrate 1 has a main surface 11 and a back surface 13. Based on the crystal structure of the substrate 1, the main surface 11 and the back surface 13 are both oriented in the (100) plane. The main surface 11 and the back surface 13 face opposite sides in the z direction. Figure 4As shown, in thermal print head A10, main surface 11 faces platen roller 79, and back surface 13 faces wiring substrate 71. Substrate 1 also has convex surface 12. Convex surface 12 is connected to main surface 11 and protrudes in the z-direction toward the side facing main surface 11. Convex surface 12 extends along the x-direction.

[0047] like Figure 6 As shown, the convex surface 12 has a top surface 121 and a pair of inclined surfaces 122. The top surface 121 is spaced apart from the main surface 11 in the z-direction and is parallel to the main surface 11. The pair of inclined surfaces 122 are spaced apart from each other in the y-direction. The pair of inclined surfaces 122 are connected to the top surface 121 and the main surface 11. The pair of inclined surfaces 122 are inclined relative to the main surface 11 so as to approach each other from the main surface 11 to the top surface 121. The pair of inclined surfaces 122 have the same inclination angle α relative to the main surface 11.

[0048] like Figure 6 As shown, a protrusion 19 is formed on the substrate 1. The protrusion 19 protrudes from the main surface 11 in the z direction and extends in the x direction. The protrusion 19 is formed on the convex surface 12. Therefore, the configuration of the protrusion 19 is based on the shape of the protrusion 19.

[0049] like Figure 5 As shown, the glaze layer 21 is formed in contact with the top surface 121 of the convex surface 12 of the substrate 1. The glaze layer 21 contains, for example, amorphous glass. Therefore, the glaze layer 21 contains a material containing glass. The linear expansion coefficient of the glaze layer 21 is approximately the same as that of the substrate 1. Figure 6 As shown, the glaze layer 21 protrudes in the z direction toward the side facing the top surface 121. The glaze layer 21 does not contact the pair of inclined surfaces 122 of the convex surface 12. The dimension H of the glaze layer 21 in the z direction is the largest at the center of the glaze layer 21 in the y direction.

[0050] like Figure 6 As shown, the glaze layer 21 has a pair of end edges 211. The pair of end edges 211 are in contact with the top surface 121 of the convex surface 12 of the substrate 1 and are separated from each other in the y direction. Figure 7 and Figure 8 As shown, when viewed along the z direction, the pair of end edges 211 each include a receding section 211A. The receding section 211A is located on the inner side of the top surface 121 relative to the boundary 123 between the top surface 121 and the pair of inclined surfaces 122 of the convex surface 12 . Figure 7 This shows a case where the receding section 211A is continuously formed throughout the entire section of each of the pair of end edges 211 . Figure 8 This shows that the setback section 211A is formed discontinuously in the entire section or a part of the section of each of the pair of end edges 211. The setback section 211A includes Figure 7 and Figure 8These two cases. The distance d (refer to Figures 7-9 ) from either of the junctions 123 of the top surface 121 and the pair of inclined surfaces 122 to the retreat section 211A exceeds 0 μm and is 15 μm or less.

[0051] As shown in Figure 9 , the glaze layer 21 has a peripheral edge 212. The peripheral edge 212 is an edge of the glaze layer 21 that links the pair of end edges 211 in a cross section in both the z direction and the y direction and protrudes in the z direction toward the side to which the top surface 121 faces. In this cross section, the peripheral edge 212 is curved. In this cross section, the peripheral edge 212 includes an edge end portion 212A that connects either of the pair of end edges 211. The edge end portion 212A is curved, and the curve is convex in the z direction toward the side to which the top surface 121 of the convex surface 12 of the substrate 1 faces. In this cross section, the tangent line TL of the edge end portion 212A of the end edge 211 has an inclination angle β with respect to the top surface 121 that is smaller than the inclination angle α described above.

[0052] As shown in Figure 6 , the insulating layer 22 covers the main surface 11 of the substrate 1, the pair of top surfaces 121 of the convex surface 12 of the substrate 1, and the glaze layer 21. With the insulating layer 22, the substrate 1 is electrically insulated from the resistance layer 3 and the wiring layer 4. The insulating layer 22 includes, for example, silicon dioxide (SiO2) that uses tetraethyl orthosilicate (TEOS) as a raw material. The thickness of the insulating layer 22 is, for example, 1 μm or more and 15 μm or less.

[0053] As shown in Figure 5 and Figure 6 , the resistance layer 3 is formed on the main surface 11 and the convex surface 12 of the substrate 1. The resistance layer 3 is in contact with the insulating layer 22. Thus, in the thermal printhead A10, the insulating layer 22 is configured to be interposed between the substrate 1 and the resistance layer 3. The resistance layer 3 includes, for example, tantalum nitride (TaN). The thickness of the resistance layer 3 is, for example, 0.02 μm or more and 0.1 μm or less.

[0054] As shown in Figure 2 , Figure 3 and Figure 6 , the resistance layer 3 includes a plurality of heat generating portions 31. In the resistance layer 3, the plurality of heat generating portions 31 are portions that are exposed from the wiring layer 4. The plurality of heat generating portions 31 locally heat the recording medium by being selectively energized from the wiring layer 4. The plurality of heat generating portions 31 are arranged in the x direction. Two of the heat generating portions 31 that are adjacent in the x direction among the plurality of heat generating portions 31 are arranged apart from each other. The plurality of heat generating portions 31 are formed on the glaze layer 21. In the thermal printhead A10, the plurality of heat generating portions 31 are formed above the top surface 121 of the convex surface 12 of the substrate 1. As shown in Figure 4As shown, in the thermal printer B10, the plurality of heat generating portions 31 face the platen roller 79. In the y direction, the plurality of heat generating portions 31 are located at the center of the glaze layer 21 in the y direction.

[0055] Figure 10 FIG. 1 is a partially enlarged cross-sectional view showing a thermal print head A11 as a variation of the thermal print head A10. Figure 10 As shown, in the y-direction, the plurality of heat generating portions 31 are located between the y-direction center of the glaze layer 21 and one of the pair of end edges 211 of the glaze layer 21. In the y-direction, the plurality of heat generating portions 31 are located above the glaze layer 21 and displaced toward the downstream side. In the y-direction, the upstream end of the plurality of heat generating portions 31 may be located above the y-direction center of the glaze layer 21, or may be displaced from above the center toward either the upstream or downstream side.

[0056] like Figure 5 and Figure 6 As shown, the wiring layer 4 is formed in contact with the resistor layer 3. The wiring layer 4 constitutes a conductive path for energizing the multiple heat generating portions 31 of the resistor layer 3. The resistivity of the wiring layer 4 is lower than that of the resistor layer 3. The wiring layer 4 is, for example, a metal layer containing copper (Cu). The thickness of the wiring layer 4 is, for example, not less than 0.3 μm and not more than 2.0 μm. In addition, the wiring layer 4 can also be constituted by two metal layers including a titanium (Ti) layer stacked on the resistor layer 3 and a copper layer stacked on the titanium layer. In this case, the thickness of the titanium layer is, for example, not less than 0.1 μm and not more than 0.2 μm.

[0057] like Figure 2 As shown, the wiring layer 4 includes a common wiring 41 and a plurality of individual wirings 42. The common wiring 41 is located on one side of the y direction relative to the plurality of heat generating portions 31 of the resistor layer 3. The plurality of individual wirings 42 are located on the other side of the y direction relative to the plurality of heat generating portions 31. Figure 3 As shown, when viewed along the z direction, the regions of the resistor layer 3 sandwiched between the common wiring 41 and the individual wirings 42 are the heat generating portions 31 .

[0058] like Figure 2 and Figure 3As shown, the common wiring 41 has a base 411 and a plurality of extensions 412. In the y direction, the position of the base 411 is farthest from the plurality of heat generating portions 31 of the resistor layer 3. When viewed along the z direction, the base 411 is in the shape of a strip extending along the x direction. The plurality of extensions 412 are in the shape of a strip extending from the end of the base 411 opposite to the protrusion 19 of the substrate 1 toward the plurality of heat generating portions 31 in the y direction. The plurality of extensions 412 are arranged along the x direction. A portion of each of the plurality of extensions 412 is formed on the inclined surface 122 of the substrate 1 that is opposite to the base 411. Therefore, a portion of the common wiring 41 is formed on any one of the pair of inclined surfaces 122. In the common wiring 41, current flows from the base 411 to the plurality of heat generating portions 31 via the plurality of extensions 412.

[0059] like Figure 2 and Figure 3 As shown, the multiple individual wirings 42 each have a base 421 and an extension 422. In the y direction, the position of the base 421 is farthest from the multiple heat-generating parts 31 of the resistor layer 3. The bases 421 of the multiple individual wirings 42 are arranged in a zigzag configuration in the x direction. To be more specific, the bases 421 of the multiple individual wirings 42 include two columns of bases 421 respectively arranged in the x direction. In each column of the two columns of bases 421, the multiple bases 421 are arranged along the x direction with equal spacing p (the spacing p is the distance between the centers of the two adjacent bases 421 in the first direction x). In the two columns of bases 421, the column of bases 421 located on the upstream side and the column of bases 421 located on the downstream side are arranged in the x direction with an offset distance of 1 / 2 of the spacing p.

[0060] like Figure 2 and Figure 3 As shown, the extension portion 422 is in the shape of a strip extending from the end of the base portion 421 opposite to the protrusion 19 of the substrate 1 in the y direction toward the multiple heat generating portions 31. The extension portions 422 of the multiple individual wirings 42 are arranged along the x direction. The extension portion 422 of each of the multiple individual wirings 42 is formed on the inclined surface 122 of the substrate 1 that is opposite to the base portion 421 of the multiple individual wirings 42. Therefore, a portion of each of the multiple individual wirings 42 is formed on any one of the pair of inclined surfaces 122. In each of the multiple individual wirings 42, current flows from any one of the multiple heat generating portions 31 to the base portion 421 via the extension portion 422. When viewed along the z direction, the multiple heat generating portions 31 are respectively sandwiched between any one of the extension portions 422 of the multiple individual wirings 42 and any one of the multiple extension portions 412 of the common wiring 41. Figure 2 and Figure 3 The configuration of the wiring layer 4 and the plurality of heat generating portions 31 shown in the figure is an example. The configuration of the wiring layer 4 and the plurality of heat generating portions 31 in the present invention is not limited to the configuration of the wiring layer 4 and the plurality of heat generating portions 31 shown in the figure. Figure 2 andFigure 3 The configuration is shown.

[0061] As Figure 5 shown, the protective layer 5 covers a part of the main surface 11 of the substrate 1, the plurality of heat generating portions 31 of the resistance layer 3, and the wiring layer 4. The protective layer 5 has electrical insulating properties. Silicon is contained in the composition of the protective layer 5. The protective layer 5 contains, for example, any one of silicon dioxide, silicon nitride (Si3N4), and silicon carbide (SiC). Alternatively, the protective layer 5 can be a laminate containing a plurality of kinds of these substances. The thickness of the protective layer 5 is, for example, 1.0 μm or more and 10 μm or less. In the thermal printer B10, the recording medium is pressed against the region of the protective layer 5 that covers the plurality of heat generating portions 31 by the platen roller 79 shown. Figure 4 The platen roller 79 shown presses the recording medium against the region of the protective layer 5 that covers the plurality of heat generating portions 31.

[0062] As Figure 5 shown, the wiring openings 51 are provided in the protective layer 5. The wiring openings 51 penetrate the protective layer 5 in the z direction. A part of the base portions 421 of the plurality of individual wirings 42 and a part of the extension portions 422 of the plurality of individual wirings 42 are exposed from the wiring openings 51.

[0063] As Figure 4 shown, the wiring substrate 71 is located beside the substrate 1 in the y direction. As Figure 1 shown, the plurality of individual wirings 42 are located between the plurality of heat generating portions 31 of the resistance layer 3 and the wiring substrate 71 in the y direction as viewed in the z direction. The area of the wiring substrate 71 is larger than the area of the substrate 1 as viewed in the z direction. Further, the wiring substrate 71 is rectangular as viewed in the z direction with the x direction as the long side direction. The wiring substrate 71 is, for example, a PCB (Printed Circuit Board) substrate. The plurality of drive elements 73 and the connector 77 are mounted on the wiring substrate 71.

[0064] As Figure 4 shown, the heat sink 72 faces the back surface 13 of the substrate 1. The back surface 13 is joined to the heat sink 72. The wiring substrate 71 is fixed to the heat sink 72 with a fastening member such as a screw. When the thermal print head A10 is used, a part of the heat generated from the plurality of heat generating portions 31 of the resistance layer 3 is conducted to the heat sink 72 via the substrate 1. The heat conducted to the heat sink 72 is released to the outside. The heat sink 72 contains, for example, aluminum (Al).

[0065] As Figure 1 and Figure 4As shown, the plurality of drive elements 73 are mounted on the wiring substrate 71 with a die-bonding material (not shown) having electrical insulation. The plurality of drive elements 73 are each a semiconductor element that constitutes various circuits. On the plurality of drive elements 73, one end of each of a plurality of first leads 74 and one end of each of a plurality of second leads 75 are respectively bonded. The other ends of the plurality of first leads 74 are individually bonded to the base portions 421 of the plurality of individual wires 42. The other ends of the plurality of second leads 75 are bonded to a wiring (not shown) provided in the wiring substrate 71 and in conduction with the connector 77. Thus, a print signal, a control signal, and a voltage to be supplied to the plurality of heat generating portions 31 of the resistance layer 3 are input from the outside to the plurality of drive elements 73 via the connector 77. The plurality of drive elements 73 selectively apply a voltage to the plurality of individual wires 42 based on these electrical signals. Thus, the plurality of heat generating portions 31 selectively generate heat.

[0066] As shown in Figure 4 , the sealing resin 76 covers the plurality of drive elements 73, the plurality of first leads 74, and the plurality of second leads 75, and a portion of each of the substrate 1 and the wiring substrate 71. The sealing resin 76 has electrical insulation. The sealing resin 76 is, for example, a black and soft synthetic resin used for underfilling. Further, the sealing resin 76 can be a black and hard synthetic resin.

[0067] As shown in Figure 1 and Figure 4 , the connector 77 is mounted on one end of the wiring substrate 71 in the y direction. The connector 77 is connected to the thermal printer B10. The connector 77 has a plurality of pins (not shown). A portion of the plurality of pins is in conduction with a wiring (not shown) in the wiring substrate 71 to which the plurality of second leads 75 are bonded. Further, another portion of the plurality of pins is in conduction with a wiring (not shown) in the wiring substrate 71 that is in conduction with the base portion 411 of the common wiring 41.

[0068] Next, an example of a manufacturing method of the thermal printhead A10 will be described. Here, Figures 11-22 , and Figures 11-13 , the cross-sectional position of Figures 16-22 is the same as that of Figure 5 representing the main part of the thermal printhead A10.

[0069] First, as shown in Figure 11 and Figure 12 , the convex portion 19 is formed on the base material 81.

[0070] First, as shown in Figure 11As shown, a first mask layer 891 covering the substrate 81 and a second mask layer 892 covering a portion of the first mask layer 891 are formed. The substrate 81 includes a semiconductor material. The semiconductor material includes a single crystal material composed of silicon. The substrate 81 is a silicon wafer. In a direction perpendicular to the z direction, a portion formed by connecting multiple regions corresponding to multiple substrates 1 corresponds to the substrate 81. The substrate 81 has a first surface 81A and a second surface 81B. The first surface 81A and the second surface 81B face opposite sides in the z direction. The plane orientations of the first surface 81A and the second surface 81B based on the crystal structure of the substrate 81 are both (100) planes. The first mask layer 891 is formed in a manner covering the first surface 81A and the second surface 81B. The first mask layer 891 includes silicon dioxide. The second mask layer 892 is formed in a manner covering the region of the first mask layer 891 covering the first surface 81A. The second mask layer 892 includes silicon nitride. A mask opening 893 is formed in the region of the first mask layer 891 covering the first surface 81A and the second mask layer 892 covering the region. The mask opening 893 penetrates in the z direction.

[0071] When forming the first mask layer 891 and the second mask layer 892, a silicon dioxide film is first formed by thermal oxidation to cover the first surface 81A and the second surface 81B. Next, a silicon nitride film is formed by thermal CVD (Chemical Vapor Deposition) to cover the area of ​​the first mask layer 891 covering the first surface 81A. Finally, photolithography patterning and reactive ion etching (RIE) are used to remove a portion of the silicon dioxide film covering the first surface 81A and a portion of the silicon nitride film covering this area. Thus, the first mask layer 891 and the second mask layer 892 are formed, and mask openings 893 are formed in the area of ​​the first mask layer 891 covering the first surface 81A and the area of ​​the second mask layer 892 covering this area.

[0072] A silicon nitride thin film covering the first surface 81A and the second surface 81B may be formed by thermal CVD as the first mask layer 891. In this case, photolithographic patterning and reactive ion etching are performed to form mask openings 893 on the first surface 81A, including a designated area covered by the first mask layer 891 and an area outside the designated area where the first surface 81A is exposed.

[0073] Then, if Figure 12 As shown, the main surface 11 and the protrusions 19 are formed on the substrate 81. The main surface 11 and the protrusions 19 are formed by using a potassium hydroxide (KOH) aqueous solution. Figure 11The area of ​​the first surface 81A exposed at the mask opening 893 shown is formed by wet etching. This etching is anisotropic. Finally, the first mask layer 891 and the second mask layer 892 are removed by wet etching using hydrofluoric acid (HF). Through the above treatment, the main surface 11 and the protrusion 19 are formed on the substrate 81. Furthermore, the second surface 81B of the substrate 81 becomes the back surface 13. The protrusion 12 is connected to the main surface 11 and protrudes from the main surface 11 in the z direction. The protrusion 19 protrudes from the main surface 11 in the z direction and extends along the x direction. The protrusion 19 includes the protrusion 12. The area of ​​the first surface 81A covered by the first mask layer 891 and the second mask layer 892 becomes the top surface 121 of the protrusion 12. Furthermore, the pair of inclined surfaces 122 of the protrusion 12 each have the same inclination angle α relative to the main surface 11. This is because the protrusion 19 is formed by anisotropic etching.

[0074] After forming the main surface 11 and the protrusions 19 on the substrate 81, a silicon dioxide thin film may be formed by thermal oxidation to cover the main surface 11. A metal layer may be deposited by plating on the bases 421 of the plurality of individual wirings 42 to which the plurality of first conductive wires 74 are individually connected. When the metal layer is deposited by plating, the silicon dioxide thin film has the effect of suppressing abnormal growth of the metal layer.

[0075] Then, if Figure 13 As shown, a glaze layer 21 is formed in contact with the top surface 121 of the convex surface 12 of the substrate 81. The glaze layer 21 is formed by supplying a glaze material as a fluid to the top surface 121 and then firing the glaze material. The glaze material is sprayed from a dispenser, for example. The glaze material includes glass such as amorphous glass. The glaze material can also be applied repeatedly. The glaze material shrinks due to firing. Therefore, as shown in FIG. Figure 14 and Figure 15 As shown, the pair of end edges 211 of the glaze layer 21 are formed to include the above-mentioned receding interval 211A (in one example of this manufacturing method, Figure 7 As another example of the method for supplying the glaze material, there is a method of printing the glaze material on the top surface 121 using a screen.

[0076] Then, if Figure 16 As shown, an insulating layer 22 is formed to cover the main surface 11 of the substrate 81, the pair of inclined surfaces 122 of the convex surface 12 of the substrate 81, and the glaze layer 21. The insulating layer 22 is formed by laminating a silicon dioxide thin film formed by plasma CVD using tetraethyl orthosilicate (TEOS) as a raw material gas multiple times.

[0077] Then, if Figures 17-20The resistance layer 3 and the wiring layer 4 are formed. The resistance layer 3 includes a plurality of heat generating portions 31 arranged in the x direction. The wiring layer 4 is in conduction with the plurality of heat generating portions 31. Further, the process of forming the wiring layer 4 includes the processes of forming the common wiring 41 and the plurality of individual wirings 42. In the substrate 81, the common wiring 41 is located on the one side in the y direction with respect to Figure 20 The plurality of heat generating portions 31 of the resistance layer 3 shown are located on the one side in the y direction. In the substrate 81, the plurality of individual wirings 42 are located on the other side in the y direction with respect to Figure 20 The plurality of heat generating portions 31 shown are located on the other side in the y direction.

[0078] First, as shown in FIG. 1, the resistance film 82 is formed on the main face 11 and the convex face 12 of the substrate 81. The resistance film 82 is formed so as to cover the entire face of the insulating layer 22. The resistance film 82 is formed by laminating a tantalum nitride thin film on the insulating layer 22 using a sputtering method. Figure 17 Next, as shown in FIG. 2, the conductive layer 83 covering the entire face of the resistance film 82 is formed. The conductive layer 83 is formed by laminating a copper thin film on the resistance film 82 using a sputtering method. Further, in forming the conductive layer 83, a method in which a titanium thin film is laminated on the resistance film 82 using a sputtering method, and then a copper thin film is laminated on the titanium thin film using a sputtering method can also be employed.

[0079] Figure 18 Next, as shown in FIG. 3, after the conductive layer 83 is subjected to photolithographic patterning, a part of the conductive layer 83 is removed. This removal is performed by wet etching using a mixed solution of sulfuric acid (H2SO4) and hydrogen peroxide (H2O2). Thus, the common wiring 41 and the plurality of individual wirings 42 are formed in contact with the resistance film 82. Therefore, the formation of the wiring layer 4 is completed by this process. Further, the region of the resistance film 82 formed on the top face 121 of the convex face 12 of the substrate 81 is exposed from the wiring layer 4.

[0080] Next, as shown in FIG. 4, after the resistance film 82 and the wiring layer 4 are subjected to photolithographic patterning, a part of the resistance film 82 is removed. This removal is performed by reactive ion etching. Thus, the resistance layer 3 is formed on the main face 11 and the convex face 12 of the substrate 81. The plurality of heat generating portions 31 appear on the top face 121 of the substrate 81. Figure 19 Next, as shown in FIG. 5, the protective layer 5 covering a part of the main face 11 of the substrate 81, the plurality of heat generating portions 31 of the resistance layer 3, and the wiring layer 4 is formed. The protective layer 5 is formed by laminating a silicon nitride thin film using plasma CVD.

[0081] Figure 20 Next, as shown in FIG. 6, the protective layer 5 is subjected to photolithographic patterning, and then a part of the protective layer 5 is removed. This removal is performed by dry etching using a chlorine gas (Cl2) gas. Thus, the protective layer 5 is formed on the main face 11 of the substrate 81, the plurality of heat generating portions 31 of the resistance layer 3, and the wiring layer 4.

[0082] Next, as shown in FIG. 7, the protective layer 5 is subjected to photolithographic patterning, and then a part of the protective layer 5 is removed. This removal is performed by dry etching using a chlorine gas (Cl2) gas. Thus, the protective layer 5 is formed on the main face 11 of the substrate 81, the plurality of heat generating portions 31 of the resistance layer 3, and the wiring layer 4. Figure 21 Next, as shown in FIG. 8, the protective layer 5 is subjected to photolithographic patterning, and then a part of the protective layer 5 is removed. This removal is performed by dry etching using a chlorine gas (Cl2) gas. Thus, the protective layer 5 is formed on the main face 11 of the substrate 81, the plurality of heat generating portions 31 of the resistance layer 3, and the wiring layer 4.

[0083] Figure 22 ​​​The protective layer 5 is formed so as to penetrate the wiring openings 51 in the z direction. The wiring openings 51 are formed by removing a portion of the protective layer 5 after performing photolithography patterning on the protective layer 5. This removal is performed by reactive ion etching. Thus, a portion of each of the plurality of individual wirings 42 (a portion of each of the base portions 421 and the extended portions 422 of the plurality of individual wirings 42) is exposed from the wiring openings 51. The portion of each of the plurality of individual wirings 42 that is exposed from the wiring openings 51 forms, for example, a base portion 421 of each of the plurality of first conductive lines 74 that is to be individually joined by wire bonding. A metal layer such as a gold layer can be laminated on each of the portions of the plurality of individual wirings 42 (including the base portions 421) that are exposed from the wiring openings 51 by plating. Figure 5

[0084] Next, the substrate 81 is cut along the x direction and the y direction, thereby dividing the substrate 81 into individual pieces. Thus, a main portion of the thermal printhead A10 including the substrate 1 is obtained. Next, the plurality of drive elements 73 and the connector 77 are mounted on the wiring substrate 71. Next, the heat sink 72 is joined to the back surface 13 of the substrate 1 and the wiring substrate 71. Next, the plurality of first conductive lines 74 and the plurality of second conductive lines 75 are joined to the wiring substrate 71. Finally, the sealing resin 76 is formed on the substrate 1 and the wiring substrate 71 so as to cover the drive elements 73, the plurality of first conductive lines 74, and the plurality of second conductive lines 75. The thermal printhead A10 is obtained through the above processes.

[0085] Next, the effects of the thermal printhead A10 will be described.

[0086] The thermal printhead A10 includes the glaze layer 21 that is formed in contact with the top surface 121 of the convex surface 12 of the substrate 1. The glaze layer 21 includes a pair of end edges 211 that are arranged apart from each other in the y direction. The plurality of heat generating portions 31 of the resistive layer 3 are formed on the glaze layer 21. The pair of end edges 211 each include a retreat interval 211A that is located inward of the top surface 121 from the junction 123 of the top surface 121 and a pair of inclined surfaces 122 of the convex surface 12 when viewed in the z direction.

[0087] The glaze layer 21 that includes the pair of end edges 211 each including the retreat interval 211A is formed so as to be in contact with the top surface 121 of the convex surface 12 of the substrate 1. Figure 13 ​The thermal print head A10 shown in the figure is manufactured using the following method: after forming the convex portion 19 including the convex surface 12 on the substrate 81, a liquid glaze material is applied to the top surface 121 of the convex surface 12, and then the glaze material is fired. This manufacturing method causes surface tension to act on the pre-fired glaze material at the boundary 123 between the top surface 121 and the pair of inclined surfaces 122 of the convex surface 12. This surface tension suppresses deviations in the shape (peripheral edge 212) of the glaze layer 21. By including this glaze layer 21 in the thermal print head A10, the size of the convex portion 19 can be suppressed, and the contact area between the recording medium and the thermal print head A10 can be reduced. Furthermore, the glaze layer 21 accumulates the heat generated by the multiple heating elements 31. Thus, the thermal print head A10 can, firstly, achieve improved printing energy efficiency. Secondly, it can improve the quality of printing on the recording medium using the multiple heating elements 31. Thirdly, the glaze layer 21 can be efficiently formed on the substrate 1 , and the shape accuracy of the glaze layer 21 can be improved.

[0088] The glaze layer 21 protrudes in the z-direction toward the side toward which the top surface 121 of the convex surface 12 faces. Ideally, the periphery 212 of the glaze layer 21 forms a curve in cross-sections along both the z- and y-directions. This results in smoother shapes for the multiple heating elements 31 and a portion of the wiring layer 4 formed on the glaze layer 21. This helps improve the quality of printing on recording media using the multiple heating elements 31.

[0089] The dimension H of the glaze layer 21 in the z direction (see Figure 6 ) is greatest at the center of the glaze layer 21 in the y direction. Furthermore, in the y direction, the multiple heating elements 31 are located at the center of the glaze layer 21 in the y direction. Thus, when the thermal printhead A10 is used, the recording medium comes into partial contact with the multiple heating elements 31. This prevents the thermal influence of the multiple heating elements 31 on the recording medium from being excessively expanded, thereby improving the quality of printing on the recording medium using the multiple heating elements 31.

[0090] In the cross-sections along the z-direction and the y-direction, the peripheral edge 212 of the glaze layer 21 includes an edge portion 212A connected to one of the pair of end edges 211. The edge portion 212A is curved and convex toward the side toward which the top surface 121 of the convex surface 12 faces in the z-direction. Figure 9 As shown in the cross section, the inclination angle β of the tangent line TL passing through the edge portion 212A of the edge 211 relative to the top surface 121 is smaller than the inclination angle α of each of the pair of inclined surfaces 122 of the convex surface 12 relative to the main surface 11. Figure 13 The manufacturing process of the thermal print head A10 shown here shows that the surface tension acting on the liquid glaze material is in an active state suitable for improving the shape accuracy of the glaze layer 21.

[0091] In the thermal head A10, a part of the common wiring 41 and a part of each of the plurality of individual wirings 42 are formed on either of the pair of inclined surfaces 122 of the convex surface 12. Thereby, the plurality of heat generating portions 31 can be made smaller in the y direction as viewed in the z direction, and the contact area of the recording medium with the thermal head A10 can be further reduced when the thermal head A10 is used. Thus, the amount of heat generated by the thermal head A10 can be suppressed, and the print quality of the recording medium can be further improved.

[0092] In the substrate 1, the pair of inclined surfaces 122 are inclined with respect to the main surface 11 in a manner of approaching each other from the main surface 11 to the top surface 121. This shape of the convex surface 12 is exhibited by forming the convex portion 19 in the base material 81 by anisotropic etching in the manufacturing process of the thermal head A10 shown in FIG. 1. Figure 12 This is because the base material 81 contains a semiconductor material, and the semiconductor material contains a single crystal material having silicon as a component.

[0093] The thermal head A10 is provided with the protective layer 5 that covers the insulating layer 22, the plurality of heat generating portions 31, and the wiring layer 4. Thereby, the plurality of heat generating portions 31 and the wiring layer 4 are protected by the protective layer 5, and the frictional force of the recording medium against the thermal head A10 can be reduced when the thermal head A10 is used.

[0094] The thermal head A10 is further provided with the heat sink 72. The back surface 13 of the substrate 1 is joined to the heat sink 72. Thereby, a part of the heat emitted from the plurality of heat generating portions 31 can be quickly released to the outside via the substrate 1 and the heat sink 72 when the thermal head A10 is used.

[0095] [2nd Embodiment]

[0096] Based on Figure 23 and Figure 24 A thermal head A20 of a 2nd embodiment of the present application will be described. In these drawings, the same symbols are attached to elements that are the same as or similar to those of the thermal head A10 described above, and repeated description will be omitted. Here, Figure 23 the cross-sectional position of the thermal head A10 described above. Figure 5 the cross-sectional position of the thermal head A10 described above.

[0097] In the thermal head A20, the configuration of the convex surface 12 of the substrate 1 and the configuration of the plurality of heat generating portions 31 of the resistive layer 3 are different from the relevant configurations of the thermal head A10 described above.

[0098] As Figure 23 and Figure 24As shown, the pair of inclined surfaces 122 of the convex surface 12 includes a first region 122A and a second region 122B. The first region 122A is connected to the main surface 11 of the substrate 1. The second region 122B is connected to the top surface 121 of the convex surface 12 and the first region 122A. In each of the pair of inclined surfaces 122, the inclination angle α2 of the second region 122B relative to the main surface 11 is smaller than the inclination angle α1 of the first region 122A relative to the main surface 11. Such a pair of inclined surfaces 122 is formed by Figure 12 The process shown is Figure 13 During the steps shown, the top surface 121 and the boundary 123 between the pair of inclined surfaces 122 and their vicinities are wet-etched using a tetramethylammonium hydroxide (TMAH) aqueous solution.

[0099] like Figure 24 As shown, the multiple heat generating portions 31 of the resistor layer 3 are formed as follows. First, in the y-direction, the multiple heat generating portions 31 are positioned above the glaze layer 21 and displaced toward the downstream side. Second, in the y-direction, the upstream ends of the multiple heat generating portions 31 can be positioned above the y-direction center of the glaze layer 21, or can be displaced from above the center toward either the upstream or downstream side.

[0100] Next, the effects of the thermal print head A20 will be described.

[0101] The thermal print head A20 includes a glaze layer 21 formed in contact with the top surface 121 of the convex surface 12 of the substrate 1. The glaze layer 21 has a pair of end edges 211 spaced apart from each other in the y-direction. The multiple heating elements 31 of the resistor layer 3 are formed on the glaze layer 21. When viewed in the z-direction, each of the pair of end edges 211 includes a recessed section 211A located inward of the top surface 121 relative to the boundary 123 between the top surface 121 and the pair of inclined surfaces 122 of the convex surface 12. The thermal print head A20 includes this glaze layer 21, which reduces the size of the convex portion 19 and reduces the contact area between the recording medium and the thermal print head A20. Furthermore, the glaze layer 21 accumulates the heat generated by the multiple heating elements 31. Thus, the thermal print head A20 can, firstly, improve printing energy efficiency. Secondly, it can enhance the quality of printing on the recording medium using the multiple heating elements 31. Thirdly, the glaze layer 21 can be efficiently formed on the substrate 1 , and the shape accuracy of the glaze layer 21 can be improved.

[0102] In the thermal head A20, the pair of inclined surfaces 122 of the convex surface 12 each include a first region 122A and a second region 122B. The first region 122A is connected to the main surface 11 of the substrate 1. The second region 122B is connected to the top surface 121 of the convex surface 12 and the first region 122A. Of the pair of inclined surfaces 122, the second region 122B has a smaller inclination angle a2 with respect to the main surface 11 than the first region 122A has an inclination angle a1 with respect to the main surface 11. With this configuration, the shape of a portion of the wiring layer 4 formed along the convex surface 12 is smoother. Also, in the wiring layer 4 formed along the convex surface 12, the occurrence of defects, disconnections, and the like in the wiring pattern is suppressed.

[0103] The present application is not limited to the above-described embodiments. The specific configurations of the parts of the present application can be freely designed with various modifications.

[0104] The technical configurations of the thermal head, the manufacturing method of the thermal head, and the thermal printer according to the present application are described below.

[0105] [Note 1]

[0106] A thermal head characterized by comprising:

[0107] a substrate having a main surface facing in a thickness direction and a convex surface connected to the main surface and protruding in the thickness direction toward the side on which the main surface faces;

[0108] a resistance layer including a plurality of heat generating portions arranged in a main scanning direction and formed on the main surface and the convex surface; and

[0109] a wiring layer formed in contact with the resistance layer and in conduction with the plurality of heat generating portions; and

[0110] the convex surface includes a top surface parallel to the main surface and a pair of inclined surfaces connected to the top surface and the main surface and arranged apart from each other in a sub scanning direction,

[0111] the thermal head further comprises a glaze layer having a pair of end edges arranged apart from each other in the sub scanning direction and formed in contact with the top surface;

[0112] the plurality of heat generating portions are formed on the glaze layer,

[0113] the pair of end edges each include a retreat interval located inward of the top surface from the intersection of the top surface and the pair of inclined surfaces, as viewed in the thickness direction.

[0114] [Note 2]

[0115] The thermal printhead according to the supplementary note 1, wherein the convex surface extends along the main scanning direction,

[0116] The glaze layer is convex toward a side of the thickness direction toward the top surface.

[0117] [Supplementary Note 3]

[0118] The thermal printhead according to the supplementary note 2, wherein a distance from any of the intersections of the top surface and the pair of inclined surfaces to the retreat interval exceeds 0 μm and is 15 μm or less.

[0119] [Supplementary Note 4]

[0120] The thermal printhead according to the supplementary note 2 or 3, wherein in a cross section along both the thickness direction and the sub-scanning direction, a periphery of the glaze layer is curved.

[0121] [Supplementary Note 5]

[0122] The thermal printhead according to the supplementary note 4, wherein a dimension of the glaze layer in the thickness direction is largest at a center of the sub-scanning direction of the glaze layer.

[0123] [Supplementary Note 6]

[0124] The thermal printhead according to the supplementary note 5, wherein in the sub-scanning direction, the plurality of heat generating portions are located at the center of the sub-scanning direction of the glaze layer.

[0125] [Supplementary Note 7]

[0126] The thermal printhead according to the supplementary note 5, wherein in the sub-scanning direction, the plurality of heat generating portions are located between the center of the sub-scanning direction of the glaze layer and one of the pair of end edges.

[0127] [Supplementary Note 8]

[0128] The thermal printhead according to any one of the supplementary notes 4 to 7, wherein in the cross section, the periphery of the glaze layer includes an edge end portion connected to any of the pair of end edges,

[0129] the edge end portion is curved, the curve being convex toward a side of the thickness direction toward the top surface,

[0130] in the cross section, a tangent line to the edge end portion of the end edge has a smaller inclination angle with respect to the top surface than each of the pair of inclined surfaces has with respect to the main surface.

[0131] [Supplementary Note 9]

[0132] The thermal printhead according to any one of the following notes 1 to 8, wherein the glaze layer contains a material containing glass.

[0133] [Note 10]

[0134] The thermal printhead according to any one of the following notes 1 to 9, wherein the pair of inclined surfaces are inclined in a manner approaching each other from the main surface to the top surface.

[0135] [Note 11]

[0136] The thermal printhead according to Note 10, wherein the pair of inclined surfaces respectively include a first region connected to the main surface, and a second region connected to the top surface and the first region,

[0137] the second region has a smaller inclination angle with respect to the main surface than the first region.

[0138] [Note 12]

[0139] The thermal printhead according to any one of the following notes 1 to 11, wherein the substrate contains a semiconductor material,

[0140] the semiconductor material contains a single-crystal material containing silicon as a constituent element.

[0141] [Note 13]

[0142] The thermal printhead according to any one of the following notes 1 to 12, further comprising an insulating layer covering the main surface, the pair of inclined surfaces, and the glaze layer,

[0143] the resistive layer is in contact with the insulating layer.

[0144] [Note 14]

[0145] The thermal printhead according to Note 13, wherein the wiring layer contains a common wiring, and a plurality of individual wirings,

[0146] the common wiring is located on one side in the sub-scanning direction with respect to the plurality of heat generating portions,

[0147] the plurality of individual wirings are located on the other side in the sub-scanning direction with respect to the plurality of heat generating portions,

[0148] a portion of the common wiring is formed on the inclined surface of the pair of inclined surfaces located on the one side in the sub-scanning direction,

[0149] a portion of each of the plurality of individual wirings is formed on the inclined surface of the pair of inclined surfaces located on the other side in the sub-scanning direction.

[0150] [Note 15]

[0151] The thermal printhead according to any one of the following 13 or 14, further comprising a protective layer covering the insulating layer, the plurality of heat generating portions, and the wiring layer.

[0152] [Para 16]

[0153] The thermal printhead according to any one of the following 1 to 15, further comprising a heat sink,

[0154] The substrate has a back surface on the side opposite to the main surface in the thickness direction,

[0155] The back surface is joined to the heat sink.

[0156] [Para 17]

[0157] A thermal printer comprising:

[0158] The thermal printhead according to any one of the following 1 to 16; and

[0159] A platen roller disposed opposite to the plurality of heat generating portions.

[0160] [Para 18]

[0161] A method of manufacturing a thermal printhead, characterized by comprising the following steps:

[0162] forming a main surface facing in a thickness direction, and a convex surface connected to the main surface and protruding in the thickness direction on the side toward which the main surface faces, on a base material;

[0163] forming a resistance layer on the main surface and the convex surface, the resistance layer including a plurality of heat generating portions arranged in a main scanning direction; and

[0164] forming a wiring layer in contact with the resistance layer and in conduction with the plurality of heat generating portions; and

[0165] the convex surface includes a top surface parallel to the main surface, and a pair of inclined surfaces connected to the top surface and the main surface and disposed opposite to each other in a sub scanning direction,

[0166] between the step of forming the main surface and the convex surface and the step of forming the resistance layer, further comprising a step of forming a glaze layer in contact with the top surface,

[0167] in the step of forming the glaze layer, after supplying a glaze material as a fluid to the top surface, the glaze material is fired, thereby forming the glaze layer.

[0168] [Para 19]

[0169] The method for manufacturing a thermal printhead according to the appended note 18, wherein the glaze material comprises glass.

[0170] [Note 20]

[0171] The method for manufacturing a thermal printhead according to the appended note 18 or 19, wherein the substrate comprises a semiconductor material,

[0172] The semiconductor material comprises a single-crystal material composed of silicon.

[0173] [Note 21]

[0174] The method for manufacturing a thermal printhead according to the appended note 20, wherein in the process of forming the main face and the convex face, the main face and the convex face are formed by anisotropic etching.

[0175] [Explanation of symbols]

[0176] A10, A20: thermal printhead

[0177] 1: substrate

[0178] 11: main face

[0179] 12: convex face

[0180] 121: top face

[0181] 122: inclined face

[0182] 122A: 1st region

[0183] 122B: 2nd region

[0184] 123: boundary

[0185] 13: back face

[0186] 17: convex portion

[0187] 21: glaze layer

[0188] 211: end edge

[0189] 211A: retracted interval

[0190] 212: peripheral edge

[0191] 212A: edge end portion

[0192] 2: insulating layer

[0193] 3: resistive layer

[0194] 31: heat-generating portion

[0195] 4: wiring layer

[0196] 41: common wiring

[0197] 411: base portion

[0198] 412: extended portion

[0199] 42: individual wiring

[0200] 421: base portion

[0201] 422: extended portion

[0202] 5: protective layer

[0203] 51: wiring opening

[0204] 71: wiring substrate

[0205] 72: heat sink

[0206] 73: drive element

[0207] 74: first lead wire

[0208] 75: second lead wire

[0209] 76: sealing resin

[0210] 77: connector

[0211] 79: platen roller

[0212] 81: base material

[0213] 81A: first surface

[0214] 81B: second surface

[0215] 82: resistive film

[0216] 83: conductive layer

[0217] 891: first mask layer 892: second mask layer 893: mask opening

[0218] p: pitch

Claims

1. A thermal print head, characterized in that: have: a substrate having a main surface facing in a thickness direction and a convex surface connected to the main surface and convex in the thickness direction toward a side facing the main surface; a resistance layer including a plurality of heat generating portions arranged in a main scanning direction and formed on the main surface and the convex surface; and a wiring layer formed in contact with the resistance layer and electrically connected to the plurality of heating elements; and The convex surface includes a top surface parallel to the main surface, and a pair of inclined surfaces connected to the top surface and the main surface and arranged to be separated from each other in the sub-scanning direction. The thermal print head further includes a glaze layer having a pair of end edges spaced apart from each other in the sub-scanning direction and formed in contact with the top surface; The plurality of heat generating parts are formed on the glaze layer, When viewed in the thickness direction, the pair of end edges each include a receding section, and the receding section is located on the top surface and further inward of the top surface than a boundary between the top surface and the pair of inclined surfaces.

2. The thermal print head according to claim 1, wherein the convex surface extends along the main scanning direction, The glaze layer protrudes in the thickness direction toward the side toward which the top surface faces. 3 . The thermal print head according to claim 2 , wherein a periphery of the glaze layer is curved in cross sections along both the thickness direction and the sub-scanning direction. 4 . The thermal print head according to claim 3 , wherein a dimension of the glaze layer in the thickness direction is largest at a center of the glaze layer in the sub-scanning direction. 5 . The thermal print head according to claim 4 , wherein in the sub-scanning direction, the plurality of heat generating portions are located at a center of the glaze layer in the sub-scanning direction.

6. The thermal print head according to claim 4 or 5, wherein in the cross section, the peripheral edge of the glaze layer includes an edge portion connected to either one of the pair of end edges, The edge portion is curved, and the curve is convex toward the side of the top surface in the thickness direction. In the cross section, an inclination angle of a tangent line passing through the edge end portion of the edge with respect to the top surface is smaller than an inclination angle of each of the pair of inclined surfaces with respect to the main surface. 7 . The thermal print head according to claim 1 , wherein the glaze layer comprises a material containing glass. 8 . The thermal print head according to claim 1 , wherein the pair of inclined surfaces are inclined so as to approach each other from the main surface to the top surface.

9. The thermal print head according to claim 8, wherein the pair of inclined surfaces each include a first region connected to the main surface and a second region connected to the top surface and the first region. An inclination angle of the second region with respect to the main surface is smaller than an inclination angle of the first region with respect to the main surface.

10. The thermal print head according to any one of claims 1 to 5, wherein the substrate comprises a semiconductor material comprising a single crystal material having silicon as a component.

11. The thermal print head according to any one of claims 1 to 5, further comprising an insulating layer covering the main surface, the pair of inclined surfaces, and the glaze layer. The resistance layer is in contact with the insulation layer.

12. The thermal print head according to claim 11, wherein the wiring layer includes a common wiring and a plurality of individual wirings, The common wiring is located on one side of the plurality of heat generating portions in the secondary scanning direction. The plurality of individual wirings are located on the other side of the secondary scanning direction relative to the plurality of heat generating portions. A portion of the common wiring is formed on the inclined surface located on the one side in the sub-scanning direction among the pair of inclined surfaces. A portion of each of the plurality of individual wirings is formed on the inclined surface located on the other side in the sub-scanning direction among the pair of inclined surfaces. 13 . The thermal print head according to claim 11 , further comprising a protective layer covering the insulating layer, the plurality of heat generating portions, and the wiring layer.

14. A thermal printer comprising: The thermal print head according to any one of claims 1 to 13; and The platen roller is arranged opposite to the plurality of heat generating portions.

15. A method for manufacturing a thermal print head, characterized in that: The process includes the following steps: forming a main surface facing in the thickness direction and a convex surface connected to the main surface and convex in the thickness direction toward the side facing the main surface on the substrate; forming a resistance layer on the main surface and the convex surface, the resistance layer including a plurality of heat generating portions arranged in a main scanning direction; as well as forming a wiring layer connected to the resistance layer and conducting with the plurality of heat generating parts; and The convex surface includes a top surface parallel to the main surface, and a pair of inclined surfaces connected to the top surface and the main surface and arranged to be separated from each other in the sub-scanning direction. A step of forming a glaze layer in contact with the top surface is further provided between the step of forming the main surface and the convex surface and the step of forming the resistance layer. In the step of forming the glaze layer, a glaze material as a fluid is supplied to the top surface and then the glaze material is fired, thereby forming the glaze layer. By firing the glaze material, the glaze material shrinks so that the edge of the glaze layer retreats from the boundary between the top surface and the pair of inclined surfaces toward the inside of the top surface.

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