Thermal printhead and its manufacturing method

Abstract

This invention provides a thermal printhead and a method for manufacturing the same, which can prevent damage to the wiring layer caused by substrate breakage during manufacturing. The thermal printhead (A10) includes: a substrate (1) having a main surface (11) and a back surface (12) facing opposite sides in the z-direction, and a first end surface (13) connected to the main surface (11); a resistive layer (3) at least a portion of which is formed on the main surface (11) and includes a plurality of heating elements (31) arranged in the main scanning direction; and a wiring layer (4) which is conductive to the plurality of heating elements (31) and is formed in contact with the resistive layer (3). The first end surface (13) overlaps with the back surface (12) in the z-direction and is inclined relative to the main surface (11) in the z-direction on the side where the back surface (12) is located. The first end surface (13) is exposed from the resistive layer (3) and the wiring layer (4).

Description

Technical Field

[0001] This invention relates to thermal printheads and their manufacturing methods. Background Technology

[0002] Patent Document 1 discloses a thermal printhead having a substrate formed of a silicon-containing material. The substrate of this thermal printhead has a main surface and a protrusion extending in the main scanning direction and projecting from the main surface. As in Patent Document 1... Figure 6 As shown, multiple heating elements are arranged on the protrusion in the main scanning direction. With this structure, the printing medium can reliably contact the protrusion with the multiple heating elements, thus improving print quality. Furthermore, the substrate of this thermal printhead has the advantages of high thermal conductivity and lower cost compared to substrates made of aluminum nitride-containing materials. However, during the manufacturing of this thermal printhead, if damage occurs at the peripheral edge of the main surface of the substrate during cutting, the damage may propagate towards the main surface due to the substrate's crystalline structure. This could potentially damage the wiring layer formed on the main surface of the substrate.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent document 1: Japanese Patent Application Publication No. 2019-166824. Summary of the Invention

[0006] The problem the invention aims to solve

[0007] The present invention was made in view of the above-mentioned problems, and its object is to provide a thermal printhead and a method thereof capable of preventing damage to the wiring layer caused by substrate breakage during manufacturing.

[0008] Technical means for solving problems

[0009] A first aspect of the present invention provides a thermal printhead comprising: a substrate having a main surface and a back surface facing opposite sides in a thickness direction, and a first end surface connected to the main surface; a resistive layer including a plurality of heating elements arranged in a main scanning direction, at least a portion of which is formed on the main surface; and a wiring layer conductive to the plurality of heating elements and formed in contact with the resistive layer. The first end surface is inclined relative to the main surface in a manner that overlaps with the back surface when viewed in the thickness direction. The first end surface is exposed from the resistive layer and the wiring layer.

[0010] A second aspect of the present invention provides a method for manufacturing a thermal printhead, comprising: forming a resistive layer comprising a plurality of heating elements arranged in a main scanning direction on a substrate having a main surface facing a thickness direction; forming a wiring layer in contact with the resistive layer and communicating with the plurality of heating elements; and cutting the substrate in the thickness direction. The method further comprises, between the step of forming the wiring layer and the step of cutting the substrate, a groove recessed from the main surface and extending along a direction orthogonal to the thickness direction on the substrate. The groove has an inclined surface connected to and inclined relative to the main surface, and in the step of cutting the substrate, a cutting line of the substrate passes through the groove.

[0011] Invention Effects

[0012] The thermal printhead and its manufacturing method according to the present invention can prevent damage to the wiring layer caused by substrate breakage during manufacturing.

[0013] Other features and advantages of the invention will become more apparent from the following detailed description based on the accompanying drawings. Attached Figure Description

[0014] Figure 1 This is a plan view of the thermal printhead according to the first embodiment of the present invention, showing the protective layer.

[0015] Figure 2 yes Figure 1 A plan view of the main parts of the thermal printhead is shown.

[0016] Figure 3 yes Figure 2 A magnified view of a portion of the image.

[0017] Figure 4 It is along Figure 1 A cross-sectional view of line IV-IV.

[0018] Figure 5 yes Figure 1 The diagram shows a cross-sectional view of the main part of the thermal printhead.

[0019] Figure 6 yes Figure 5 A magnified view of a portion of the image.

[0020] Figure 7 yes Figure 5 A magnified view of a portion of the image.

[0021] Figure 8 This is an explanation Figure 1 The diagram shows a cross-sectional view of the manufacturing process of the main parts of the thermal printhead.

[0022] Figure 9 This is an explanation Figure 1 The diagram shows a cross-sectional view of the manufacturing process of the main parts of the thermal printhead.

[0023] Figure 10 This is an explanation Figure 1 The diagram shows a cross-sectional view of the manufacturing process of the main parts of the thermal printhead.

[0024] Figure 11 This is an explanation Figure 1 The diagram shows a cross-sectional view of the manufacturing process of the main parts of the thermal printhead.

[0025] Figure 12 This is an explanation Figure 1 The diagram shows a cross-sectional view of the manufacturing process of the main parts of the thermal printhead.

[0026] Figure 13 This is an explanation Figure 1 The diagram shows a cross-sectional view of the manufacturing process of the main parts of the thermal printhead.

[0027] Figure 14 This is an explanation Figure 1 The diagram shows a cross-sectional view of the manufacturing process of the main parts of the thermal printhead.

[0028] Figure 15 This is an explanation Figure 1 The diagram shows a cross-sectional view of the manufacturing process of the main parts of the thermal printhead.

[0029] Figure 16 This is an explanation Figure 1 The diagram shows a cross-sectional view of the manufacturing process of the main parts of the thermal printhead.

[0030] Figure 17 This is an explanation Figure 1 The diagram shows an enlarged cross-sectional view of the manufacturing process of the main parts of the thermal printhead.

[0031] Figure 18 This is an explanation Figure 1 The diagram shows an enlarged cross-sectional view of the manufacturing process of the main parts of the thermal printhead.

[0032] Figure 19 This is an explanation Figure 1 The diagram shows a cross-sectional view of the manufacturing process of the main parts of the thermal printhead.

[0033] Figure 20 This is an explanation Figure 1 The diagram shows an enlarged cross-sectional view of the manufacturing process of the main parts of the thermal printhead.

[0034] Figure 21 yes Figure 1 A partially enlarged cross-sectional view of the first modified example of the thermal printhead shown.

[0035] Figure 22 yes Figure 1 A partially enlarged cross-sectional view of the second modified example of the thermal printhead shown.

[0036] Figure 23 yes Figure 1 A partially enlarged cross-sectional view of the second modified example of the thermal printhead shown.

[0037] Figure 24 This is a partially enlarged plan view of the main part of the thermal printhead according to the second embodiment of the present invention, showing the protective layer.

[0038] Figure 25 It is along Figure 24 Cross-sectional view of the XXV-XXV line.

[0039] Figure 26 It is along Figure 24 Cross-sectional view of the XXVI-XXVI line.

[0040] Figure 27 It is along Figure 24 Cross-sectional view of line XXVII-XXVII.

[0041] Explanation of reference numerals in the attached figures

[0042] A10, A20, A30: Thermal printheads

[0043] B10: Thermal Printer

[0044] 1: Substrate

[0045] 11: Main side

[0046] 11A: First Edge

[0047] 11B: Second Edge

[0048] 12: Back

[0049] 13: First end face

[0050] 131: Area 1

[0051] 132: Second Region

[0052] 14: Second end face

[0053] 141: Third Region

[0054] 142: Fourth Region

[0055] 15: Middle surface

[0056] 16: Edges

[0057] 19: convex part

[0058] 191: Top surface

[0059] 192: Inclined surface

[0060] 2: Insulation layer

[0061] 3: Resistor layer

[0062] 31: Heating section

[0063] 4: Wiring layer

[0064] 41: Common wiring

[0065] 411: Base

[0066] 412: Protruding part

[0067] 42: Separate wiring

[0068] 421: Base

[0069] 422: Protruding part

[0070] 5: Protective layer

[0071] 51: Wiring opening

[0072] 52: End face

[0073] 71: Wiring board

[0074] 72: Heat dissipation components

[0075] 73: Driving element

[0076] 74: First conductor

[0077] 75: Second conductor

[0078] 76: Sealing resin

[0079] 77: Connector

[0080] 79: Paper pressure roller

[0081] 81: Substrate

[0082] 81A: First Page

[0083] 81B: Second Page

[0084] 811: Groove

[0085] 811A: Bottom surface

[0086] 811B: Inclined surface

[0087] 82: Resistor film

[0088] 83: Conductive layer

[0089] 87: First Blade

[0090] 871: Base

[0091] 872: Tip of the blade

[0092] 88: Second Blade

[0093] 891: First mask layer

[0094] 892: Second mask layer

[0095] α, β1, β2, γ: tilt angle

[0096] t1, t2, t3: thickness. Detailed Implementation

[0097] The method of carrying out the invention will be described with reference to the accompanying drawings.

[0098] [First Implementation]

[0099] based on Figures 1 to 7 The thermal printhead A10 of the first embodiment of the present invention will be described below. The thermal printhead A10 constitutes the main part of the thermal printer B10 described later. The thermal printhead A10 consists of a main part and auxiliary parts. The main part of the thermal printhead A10 includes a substrate 1, an insulating layer 2, a resistive layer 3, a wiring layer 4, and a protective layer 5. The auxiliary parts of the thermal printhead A10 include a wiring substrate 71, a heat dissipation component 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 For ease of understanding, the protective layer 5 is shown in perspective, and the illustrations of multiple first conductors 74, multiple second conductors 75, and sealing resin 76 are omitted. Figure 2 and Figure 3 For ease of understanding, the protective layer 5 is shown in the image.

[0100] For ease of explanation, the main scanning direction of the thermal printhead A10 will be referred to as the "x-direction". The secondary scanning direction of the thermal printhead A10 will be referred to as the "y-direction". The thickness direction of the substrate 1 will be referred to as the "z-direction". The z-direction is orthogonal to both the x-direction and the y-direction. In the following explanation, "viewed in the z-direction" means "viewed in the thickness direction".

[0101] In the thermal printhead A10, such as Figure 4As shown, the substrate 1, which constitutes the main part of the thermal printhead A10, is bonded to the heat dissipation member 72. Furthermore, the wiring substrate 71 is located adjacent to the substrate 1 in the y-direction. The wiring substrate 71 is also fixed to the heat dissipation member 72. A plurality of heat-generating elements 31 (details described later) forming part of the resistive layer 3 are formed on the substrate 1. The plurality of heat-generating elements 31 are selectively heated by a plurality of driving elements 73 mounted on the wiring substrate 71. The plurality of driving elements 73 are driven via a connector 77 according to printing signals sent from the outside.

[0102] Furthermore, the thermal printer B10 of the present invention, as Figure 4 As shown, the thermal printer B10 includes a thermal printhead A10 and a pressure roller 79. In the thermal printer B10, the pressure roller 79 is a roller-shaped structure that feeds recording media such as thermal paper. The pressure roller 79 presses the recording media against multiple heating elements 31, thereby printing on the recording media. In the thermal printer B10, a non-roller-shaped mechanism (non-roller mechanism) may be used instead of the pressure roller 79. This non-roller mechanism has a flat surface. Here, the flat surface includes a curved surface with a small curvature (a substantially flat surface). In the thermal printer B10, the roller-shaped mechanism including the pressure roller 79 and the non-roller mechanism are referred to as an "imprint plate". Here, for the convenience of explanation, Figure 4 The side of the recording medium supply point (for the lieutenant general) Figure 4 The right side of the middle (in the middle) is called the "upstream side". Figure 4 The side of the recording medium discharge point (for the lieutenant general) Figure 4 The left side of the middle is called the "downstream side".

[0103] Substrate 1 as shown Figure 1 As shown, the substrate is rectangular in shape, extending in the x-direction when viewed in the z-direction. Therefore, the x-direction corresponds to the long side direction of substrate 1, and the y-direction corresponds to the short side direction of substrate 1. Substrate 1 is made of semiconductor material. This semiconductor material includes single-crystal material composed of silicon (Si).

[0104] like Figure 5 As shown, substrate 1 has a main surface 11 and a back surface 12 facing opposite sides in the z-direction. The orientation of the main surface 11 and the back surface 12 of substrate 1, based on their crystalline structure, is the (100) plane (based on Miller index notation). Figure 4As shown, in the thermal printhead A10, the main surface 11 faces the pressure roller 79, and the back surface 12 faces the wiring substrate 71. The main surface 11 includes a first edge 11A and a second edge 11B. The first edge 11A and the second edge 11B correspond to the peripheral edges of the main surface 11. The first edge 11A extends in the x-direction and is located closest to the resistive layer 3. The second edge 11B extends in the y-direction. In the thermal printhead A10, the second edge 11B is connected to the first edge 11A and includes two sections located apart from each other in the x-direction.

[0105] like Figure 5 As shown, the substrate 1 has a protrusion 19. The protrusion 19 protrudes from the main surface 11 in the z-direction. Figure 1 and Figure 2 As shown, the protrusion 19 extends in the x direction.

[0106] like Figure 5 and Figure 6 As shown, the protrusion 19 has a top surface 191 and a pair of inclined surfaces 192. The top surface 191 is located away from the main surface 11 in the z-direction and is parallel to the main surface 11. The pair of inclined surfaces 192 are located away from each other in the y-direction. The pair of inclined surfaces 192 are connected to the top surface 191 and the main surface 11. The pair of inclined surfaces 192 are inclined relative to the main surface 11 in a manner that brings them closer together from the main surface 11 to the top surface 191. The inclination angle α of each of the pair of inclined surfaces 192 relative to the main surface 11 is opposite to each other.

[0107] like Figure 2 , Figure 5 and Figure 7 As shown, substrate 1 has a first end face 13, a second end face 14, and a middle surface 15. The first end face 13 is directly connected to the main surface 11. More specifically, in the thermal printhead A10, the first end face 13 is connected to the first edge 11A of the main surface 11. The first end face 13 is inclined in a manner that overlaps with the back surface 12 in the z-direction but does not overlap with the main surface 11 (except for the first edge 11A). In other words, the first end face 13 has an upper edge that coincides with the first edge 11A of the main surface 11 and a lower edge on the opposite side of the upper edge, such that in the y-direction, the upper edge is located closer to the center of substrate 1 than the lower edge. For example, in Figure 7In this design, the tilt angle of the first end face 13 relative to the main face 11 (or the y-direction) is denoted by "β1". The second end face 14 is directly connected to the back face 12. The second end face 14 is located on the opposite side of the main face 11, with the first end face 13 as a reference, in a direction orthogonal to the z-direction (the y-direction in the thermal printhead A10). The second end face 14 is tilted relative to the back face 12 at a tilt angle β2. In this invention, β2 can be 90°. The tilt angle β1 is smaller than the tilt angle β2. The intermediate surface 15 faces the z-direction and is directly connected to the first end face 13 and the second end face 14, respectively. Figure 7 In the example shown, the normal of the intermediate surface 15 is parallel to the z-direction, but the invention is not limited thereto. In the z-direction, the intermediate surface 15 is located between the main surface 11 and the back surface 12. The first end surface 13, the second end surface 14, and the intermediate surface 15 are separated from the resistive layer 3 and the wiring layer 4 and are not covered by these layers. That is, the first end surface 13, the second end surface 14, and the intermediate surface 15 are exposed from the resistive layer 3 and the wiring layer 4.

[0108] Insulating layer 2 as Figure 5 and Figure 6 As shown, the main surface 11 and protrusion 19 of the substrate 1 are covered. The substrate 1 is electrically insulated from the resistive layer 3 and the wiring layer 4 by the insulating layer 2. The insulating layer 2 is, for example, made of silicon dioxide (SiO2) made from tetraethyl orthosilicate (TEOS). The thickness of the insulating layer 2 is, for example, 1 μm or more and 15 μm or less.

[0109] Resistor layer 3 Figure 5 and Figure 6 As shown, the resistive layer 3 is formed on the main surface 11 and the protrusion 19 of the substrate 1. The resistive layer 3 is in contact with the insulating layer 2. Thus, in the thermal printhead A10, the insulating layer 2 becomes a structure sandwiched between the substrate 1 and the resistive layer 3. The resistive layer 3 is formed, for example, of tantalum nitride (TaN). An example of the thickness of the resistive layer 3 is 0.02 μm or more and 0.1 μm or less.

[0110] like Figure 2 , Figure 3 and Figure 6 As shown, the resistive layer 3 includes a plurality of heating elements 31. In the resistive layer 3, the plurality of heating elements 31 are portions exposed from the wiring layer 4. The wiring layer 4 selectively supplies power to the plurality of heating elements 31, thereby locally heating the recording medium. The plurality of heating elements 31 are arranged in the x-direction. Among the plurality of heating elements 31, two adjacent heating elements 31 in the x-direction are located away from each other. The plurality of heating elements 31 are formed in contact with the insulating layer 2. In the thermal printhead A10, the plurality of heating elements 31 are formed on the top surface 191 of the protrusion 19 of the substrate 1. The plurality of heating elements 31 are located at the center of the top surface 191 in the y-direction. Figure 4As shown, in the thermal printer B10, multiple heating elements 31 are opposite to the pressure roller 79.

[0111] Wiring layer 4, as Figure 5 and Figure 6 As shown, it is formed in contact with the resistive layer 3. The wiring layer 4 forms a conductive path for energizing the plurality of heat-generating parts 31 of the resistive layer 3. The resistivity of the wiring layer 4 is lower than that of the resistive layer 3. The wiring layer 4 is, for example, a metal layer made of copper (Cu). An example of the thickness of the wiring layer 4 is 0.3 μm or more and 2.0 μm or less. Alternatively, the wiring layer 4 may be a structure composed of two metal layers: a titanium (Ti) layer stacked on the resistive layer 3 and a copper layer stacked on the titanium layer. In this case, an example of the thickness of the titanium layer is 0.1 μm or more and 0.2 μm or less. Figure 1 As shown, the wiring layer 4 is located away from the first edge 11A and the second edge 11B of the main surface 11 of the substrate 1.

[0112] like Figure 2 As shown, wiring layer 4 includes a common wiring 41 and multiple individual wirings 42. The common wiring 41 is located on one side of the y-direction relative to the multiple heating elements 31 of resistive layer 3. The multiple individual wirings 42 are located on the other side of the y-direction relative to the multiple heating elements 31. Figure 3 As shown, viewed in the z-direction, multiple regions of the resistive layer 3 sandwiched between the common wiring 41 and multiple individual wirings 42 are multiple heat-generating parts 31.

[0113] like Figure 2 and Figure 3 As shown, the common wiring 41 has a base 411 and a plurality of protrusions 412. In the y-direction, the base 411 is located at the position furthest from the plurality of heat-generating parts 31 of the resistive layer 3. The base 411 is a strip extending in the x-direction when viewed in the z-direction. The plurality of protrusions 412 are strips extending in the y-direction from the end of the base 411 opposite to the protrusion 19 of the substrate 1 toward the plurality of heat-generating parts 31. The plurality of protrusions 412 are arranged along the x-direction. A portion of each of the plurality of protrusions 412 is formed on the inclined surface 192 opposite to the base 411 in one of a pair of inclined surfaces 192 of the protrusion 19. Therefore, a portion of the common wiring 41 is formed on either of the pair of inclined surfaces 192. In the common wiring 41, current flows from the base 411 to the plurality of heat-generating parts 31 via the plurality of protrusions 412.

[0114] like Figure 2 and Figure 3As shown, each of the plurality of individual wirings 42 has a base 421 and a protrusion 422. In the y-direction, the base 421 is located at the position furthest from the plurality of heating portions 31 of the resistive layer 3. The bases 421 of the plurality of individual wirings 42 are staggered along the x-direction. Specifically, in the illustrated example, the plurality of bases 421 are arranged to form two rows (each extending in the x-direction), in which the bases 421 constituting the row are arranged at a certain interval (equal interval distance) along the x-direction.

[0115] like Figure 2 and Figure 3 As shown, the protrusion 422 is a strip extending from the end of the base 421, which is opposite to the protrusion 19 of the substrate 1 in the y-direction, toward a plurality of heating elements 31. The protrusions 422 of a plurality of individual wirings 42 are arranged along the x-direction. Each protrusion 422 of the plurality of individual wirings 42 is formed on an inclined surface 192 opposite to the base 421 of the plurality of individual wirings 42 in a pair of inclined surfaces 192 of the substrate 1. Therefore, a portion of each of the plurality of individual wirings 42 is formed on either of the pair of inclined surfaces 192. Current flows from any of the plurality of heating elements 31 to the base 421 via the protrusion 422 in each of the plurality of individual wirings 42. Viewed in the z-direction, each of the plurality of heating elements 31 is sandwiched between any of the protrusions 422 of the plurality of individual wirings 42 and any of the protrusions 412 of the common wiring 41. Figure 2 and Figure 3 The structure of the wiring layer 4 and the plurality of heating elements 31 shown is an example. The structure of the wiring layer 4 and the plurality of heating elements 31 in this invention is not limited to this. Figure 2 and Figure 3 The structure shown.

[0116] Protective layer 5 Figure 5 As shown, a portion of the main surface 11 of the substrate 1, multiple heating elements 31 of the resistive layer 3, and the wiring layer 4 are covered. The protective layer 5 has electrical insulation properties. The protective layer 5 contains silicon in its composition. The protective layer 5 is, for example, composed of any of silicon dioxide, silicon nitride (Si3N4), and silicon carbide (SiC). Alternatively, the protective layer 5 may also be a laminate formed of multiple of these materials. 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 passes through... Figure 4 The paper pressure roller 79 shown is pressed against the area of ​​the protective layer 5 covering multiple heating elements 31.

[0117] like Figure 5 As shown, the protective layer 5 has a wiring opening 51 and an end face 52. The wiring opening 51 extends through the protective layer 5 in the z-direction. A portion of the base 421 of a plurality of individual wires 42 and a portion of the protrusion 422 of a plurality of individual wires 42 are exposed from the wiring opening 51. Figure 5and Figure 7 As shown, end face 52 and the first end face 13 of substrate 1 face ... face 1 face face face 1 face face face 1 face face face 1 face face face 1 face face face 1 face face face 1 face face face face 1 face face face face face 1 face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face face

[0118] Wiring board 71 Figure 4 As shown, it is located adjacent to substrate 1 in the y-direction. Figure 1 As shown, viewed in the z-direction, multiple individual wirings 42 are located in the y-direction between multiple heat-generating portions 31 of the resistive layer 3 and the wiring substrate 71. Viewed in the z-direction, the area of ​​the wiring substrate 71 is larger than the area of ​​the substrate 1. Furthermore, viewed in the z-direction, the wiring substrate 71 has a rectangular shape with the x-direction as its long side. The wiring substrate 71 is, for example, a PCB substrate. Multiple driving elements 73 and connectors 77 are mounted on the wiring substrate 71.

[0119] Heat dissipation component 72, etc. Figure 4 As shown, it faces the back surface 12 of the substrate 1. The back surface 12 is bonded to the heat dissipation component 72. The wiring substrate 71 is fixed to the heat dissipation component 72 by fastening members such as threaded parts. When the thermal printhead A10 is in use, a portion of the heat generated from the plurality of heating elements 31 in the resistive layer 3 is conducted to the heat dissipation component 72 via the substrate 1. The heat conducted to the heat dissipation component 72 is dissipated to the outside. The heat dissipation component 72 is formed, for example, of aluminum (Al).

[0120] Multiple drive elements 73 such Figure 1 and Figure 4 As shown, the chip bonding material (not shown) with electrical insulation is mounted on the wiring substrate 71. Each of the plurality of driving elements 73 is a semiconductor element constituting various circuits. Each of the plurality of driving elements 73 is coupled to one end of a plurality of first wires 74 and one end of a plurality of second wires 75. The other ends of the plurality of first wires 74 are independently coupled to the bases 421 of the plurality of individual wirings 42. The other ends of the plurality of second wires 75 are disposed on the wiring substrate 71 and coupled to the wiring (not shown) connected to the connector 77. Thus, printing signals, control signals, and voltages supplied to the plurality of heating elements 31 of the resistive layer 3 are input from the outside to the plurality of driving elements 73 via the connector 77. The plurality of driving elements 73 selectively apply voltages to the plurality of individual wirings 42 based on these electrical signals. Thus, the plurality of heating elements 31 selectively heat up.

[0121] Sealing resin 76 Figure 4As shown, a portion of each of the plurality of drive elements 73, plurality of first wires 74 and plurality of second wires 75, substrate 1 and wiring substrate 71 are covered. The sealing resin 76 is electrically insulating. The sealing resin 76 is, for example, a black and soft synthetic resin used in underfill. Alternatively, the sealing resin 76 may also be a black and hard synthetic resin.

[0122] Connector 77 Figure 1 and Figure 4 As shown, a connector 77 is mounted on one end of the wiring board 71 in the y-direction. The connector 77 is connected to the thermal printer B10. The connector 77 has multiple pins (not shown). A portion of these pins is connected in the wiring board 71 to a wiring (not shown) to which multiple second wires 75 are joined. Furthermore, another portion of these pins is connected in the wiring board 71 to a wiring (not shown) connected to the base 411 of a common wiring 41.

[0123] Next, based on Figures 8 to 20 An example of the manufacturing method for the thermal printhead A10 will be described here. Figures 8 to 16 and Figure 19 The cross-sectional position represents the main part of the thermal printhead A10. Figure 5 The cross-sectional positions are the same.

[0124] First, such as Figure 8 and Figure 9 As shown, a protrusion 19 is formed on the substrate 81.

[0125] First, such as Figure 8 As shown, a first mask layer 891 covering a substrate 81 and a second mask layer 892 covering a portion of the first mask layer 891 are formed. The substrate 81 is formed of a semiconductor material. The semiconductor material comprises a single-crystal material composed of silicon. The substrate 81 is a silicon wafer. A structure consisting of multiple interconnected regions corresponding to multiple substrates 1 in a direction orthogonal to the z-direction 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 to each other in the z-direction. The orientation of the first surface 81A and the second surface 81B of the substrate 81, based on their crystal structure, is the (100) plane. The first mask layer 891 is formed to cover the first surface 81A and the second surface 81B. The first mask layer 891 is formed of silicon dioxide. The second mask layer 892 is formed to cover the region of the first mask layer 891 covering the first surface 81A. The second mask layer 892 is formed of silicon nitride. A portion of the first surface 81A is exposed from the first mask layer 891 covering the first surface 81A and the second mask layer 892 covering the first mask layer 891.

[0126] During the formation of the first mask layer 891 and the second mask layer 892, firstly, a thin film of silicon dioxide covering the first surface 81A and the second surface 81B is formed using a thermal oxidation method. Next, a thin film of silicon nitride covering the area of ​​the first mask layer 891 covering the first surface 81A is formed using thermal CVD (Chemical Vapor Deposition). Finally, a portion of the area of ​​the thin film of silicon dioxide covering the first surface 81A and a portion of the thin film of silicon nitride covering that area are removed by photolithography and reactive ion etching (RIE). Thus, the first mask layer 891 and the second mask layer 892 are formed.

[0127] Next, as Figure 9 As shown, a main surface 11 and a protrusion 19 are formed on the substrate 81. The main surface 11 and the protrusion 19 are respectively... Figure 8 The region of the first surface 81A exposed from the first mask layer 891 and the second mask layer 892, as shown, was formed by wet etching using an aqueous solution of potassium hydroxide (KOH). This etching is anisotropic. Finally, the first mask layer 891 and the second mask layer 892 were removed by wet etching using hydrogen fluoride (HF). Through the above steps, a main surface 11 and a protrusion 19 are formed on the substrate 81. Further, the second surface 81B of the substrate 81 becomes the back surface 12. The protrusion 19 is connected to the main surface 11 and bulges out from the main surface 11 in the z-direction. The protrusion 19 bulges out from the main surface 11 in the z-direction and extends along the x-direction. The protrusion 19 comprises the protrusion 19. The region of the first surface 81A covered by the first mask layer 891 and the second mask layer 892 becomes the top surface 191 of the protrusion 19. Furthermore, the respective inclination angles α of the pair of inclined surfaces 192 of the protrusion 19 relative to the main surface 11 are the same. This is because the protrusion 19 is formed by anisotropic etching.

[0128] exist Figure 9 In the steps shown, after the main surface 11 and the protrusion 19 are formed on the substrate 81, a thin film of silicon dioxide covering the main surface 11 can be formed by thermal oxidation. At the base 421 of the multiple individual wirings 42 that independently bond multiple first conductors 74, a laminated metal layer is sometimes deposited. This silicon dioxide thin film has the effect of suppressing abnormal growth of the metal layer when the laminated metal layer is deposited.

[0129] Next, as Figure 10 As shown, an insulating layer 2 is formed covering the main surface 11 and the protrusion 19 of the substrate 81. The insulating layer 2 is formed by repeatedly stacking a thin film of silicon dioxide formed by plasma CVD using tetraethyl orthosilicate (TEOS) as the raw material gas.

[0130] Next, as Figures 11-13The resistive layer 3 and wiring layer 4 are shown. The resistive layer 3 includes a plurality of heating elements 31 arranged in the x-direction. The wiring layer 4 is electrically connected to the plurality of heating elements 31. Furthermore, the step of forming the wiring layer 4 includes the step of forming a common wiring 41 and a plurality of individual wirings 42. In the substrate 81, the common wiring 41 is relative to... Figure 13 The multiple heating elements 31 of the resistive layer 3 shown are located on one side in the y-direction. In the substrate 81, multiple individual wirings 42 are positioned relative to... Figure 13 The multiple heating elements 31 shown are located on the other side in the y direction.

[0131] First, such as Figure 11 As shown, a resistive film 82 is formed on the main surface 11 and the protrusion 19 of the substrate 81. The resistive film 82 is formed in such a way that it covers the entire surface of the insulating layer 2. The resistive film 82 is formed by laminating a thin film of tantalum nitride onto the insulating layer 2 using a sputtering method.

[0132] Next, as Figure 12 As shown, a conductive layer 83 is formed covering the entire surface of the resistive film 82. The conductive layer 83 is formed by repeatedly depositing a thin copper film onto the resistive film 82 using a sputtering method. Alternatively, when forming the conductive layer 83, a method can be used whereby a thin copper film is repeatedly deposited relative to the titanium film after a thin titanium film is deposited onto the resistive film 82 using a sputtering method.

[0133] Next, as Figure 13 As shown, after photolithographic patterning is performed on the conductive layer 83, a portion 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). As a result, the common wiring 41 and multiple individual wirings 42 are formed in contact with the resistive film 82. Furthermore, the region of the resistive film 82 formed on the top surface 191 of the protrusion 19 of the substrate 81 is exposed from the wiring layer 4. Afterwards, after photolithographic patterning is performed on the resistive film 82 and the wiring layer 4, a portion of the resistive film 82 is removed. This removal is performed by reactive ion etching. As a result, the resistive layer 3 is formed on the main surface 11 and the protrusion 19 of the substrate 81. Multiple heat-generating portions 31 appear on the top surface 191 of the substrate 81.

[0134] Next, as Figure 14 As shown, a protective layer 5 is formed covering a portion of the main surface 11 of the substrate 81, multiple heating elements 31 of the resistive layer 3, and the wiring layer 4. The protective layer 5 is formed by plasma CVD layering a thin film of silicon azide.

[0135] Next, as Figure 15As shown, a wiring opening 51 extending in the z-direction is formed in the protective layer 5. The wiring opening 51 is formed by removing a portion of the protective layer 5 after a photolithographic pattern has been applied relative to it. This removal is performed by reactive ion etching. Thus, a portion of a plurality of individual wirings 42 ( Figure 5 The bases 421 of the plurality of individual wires 42 and portions of the protrusions 422 of the plurality of individual wires 42 are exposed from the wiring opening 51. Each portion of the plurality of individual wires 42, and the portion exposed from the wiring opening 51, constitutes a base 421 that is independently joined to the plurality of first wires 74, for example, by wire soldering. The portions of the plurality of individual wires 42 exposed from the wiring opening 51 (including the bases 421) may be coated with a metal layer such as gold plating.

[0136] Next, as Figure 16 As shown, a groove 811 is formed in the substrate 81, recessed from the main surface 11 and extending in a direction orthogonal to the z-direction (x-direction in the thermal printhead A10). The groove 811 has a bottom surface 811A and a pair of inclined surfaces 811B. The bottom surface 811A is located between the main surface 11 and the back surface 12 in the z-direction. The pair of inclined surfaces 811B are located in the thermal printhead A10 at positions that are separated from each other in the y-direction and are connected to the bottom surface 811A and the main surface 11. The pair of inclined surfaces 811B are inclined in a manner that they move closer to each other in the z-direction from the main surface 11 toward the bottom surface 811A.

[0137] like Figure 16 As shown, the groove 811 of the substrate 81 is formed using a first blade 87. (As indicated...) Figure 17 As shown, the first blade 87 has a base 871 and a tip 872. The tip 872 extends radially from the base 871 of the first blade 87 and surrounds the base 871 circumferentially. The first blade 87 is rotated about the y-direction, and the tip 872 contacts the substrate 81, thereby forming a groove 811 in the substrate 81. The thickness t2 of the tip 872 gradually decreases as it moves radially away from the base 871 of the first blade 87. Therefore, the tip 872 has a tapered shape.

[0138] like Figure 17 As shown, the cross-sectional shape of the blade tip 872 relative to the first blade 87 in the circumferential direction is trapezoidal. Furthermore, as... Figure 18 As shown, the cross-sectional shape of the blade tip 872 can also be triangular.

[0139] exist Figure 16 In the step of forming the groove 811 on the substrate 81 shown, in addition to using the first blade 87, it can also be done after removing a portion of the insulating layer 2 and the protective layer 5. Figure 9The anisotropic etching shown forms the groove 811.

[0140] Next, as Figure 19 As shown, the substrate 81 is cut along the x and y directions in the thickness direction. The resulting monolith becomes the main part of the thermal printhead A10 containing the substrate 1. In this step, the substrate 81 is cut using a second blade 88. Figure 20 As shown, the thickness t3 of the second blade 88 is greater than that of the second blade 88. Figure 17 and Figure 18 The thickness t1 of the base 871 of the first blade 87 shown is small. In this step, during the step of cutting the substrate 81 along the x-direction, as... Figure 20 As shown, the cutting line CL of the substrate 81 passes through the groove 811. In the step of cutting the substrate 81 along the x direction, the second blade 88 contacts the bottom surface 811A of the groove 811 and moves away from the inclined surface 811B of the groove 811.

[0141] Next, a plurality of drive elements 73 and connectors 77 are mounted on the wiring board 71. Then, the back surface 12 of the substrate 1 and the wiring board 71 are bonded to the heat dissipation component 72. Next, a plurality of first wires 74 and a plurality of second wires 75 are bonded relative to the wiring board 71. Finally, a sealing resin 76 covering the drive elements 73, the plurality of first wires 74, and the plurality of second wires 75 is formed relative to the substrate 1 and the wiring board 71. Through these steps, a thermal printhead A10 is obtained.

[0142] <First Variation>

[0143] Next, based on Figure 21 The thermal printhead A11, a variant of the thermal printhead A10, will be described here. Figure 21 The position of the cross section and Figure 7 The cross-sectional positions are the same.

[0144] like Figure 21 As shown, in the thermal printhead A11, the structure of the substrate 1 differs from that of the thermal printhead A10. The second end face 14 of the substrate 1 is connected to the first end face 13 of the substrate 1. Therefore, the substrate 1 of the thermal printhead A11 has a structure without a middle surface 15. This structure is achieved through... Figure 19 In the manufacturing process of the thermal printhead A10 shown, the thickness t3 of the second blade 88 is set such that the second blade 88 contacts the bottom surface 811A and the inclined surface 811B of the groove 811.

[0145] <Second Variation>

[0146] Next, based on Figure 22The thermal printhead A12, a modified example of the thermal printhead A10, will be described here. Figure 22 The position of the cross section and Figure 7 The cross-sectional positions are the same.

[0147] like Figure 22 As shown, in the thermal printhead A12, the structure of the substrate 1 differs from that of the thermal printhead A10. The first end face 13 of the substrate 1 is connected to the back face 12 of the substrate 1. Therefore, the substrate 1 of the thermal printhead A12 has a structure that does not have a second end face 14 and a middle face 15. This structure is achieved through... Figure 16 In the manufacturing process of the thermal printhead A10 shown, a through groove 811 in the z-direction is formed on the substrate 81 using a first blade 87.

[0148] <Third Variation>

[0149] Next, based on Figure 23 The thermal printhead A13, a variant of the thermal printhead A10, will be described here. Figure 23 The position of the cross section and Figure 7 The cross-sectional positions are the same.

[0150] like Figure 23 As shown, in the thermal printhead A13, the structure of the protective layer 5 differs from that of the thermal printhead A10. The end face 52 of the protective layer 5 is orthogonal to the main surface 11 of the substrate 1. Viewed in the z-direction, the end face 52 is located on the side where the wiring layer 4 is located, further than the peripheral edge of the insulating layer 2. This structure, through... Figure 15 In the manufacturing process of the thermal printhead A10 shown, when viewed in the z-direction, it is related to... Figure 16 The groove 811 of the substrate 81 shown is formed by overlapping openings in the protective layer 5. This opening is formed simultaneously with the wiring opening 51.

[0151] Next, the function and effect of the thermal printhead A10 will be explained.

[0152] The thermal printhead A10 includes a substrate 1 having a main surface 11 and a back surface 12 facing opposite sides in the z-direction, and a first end surface 13 connected to the main surface 11. The first end surface 13 overlaps with the back surface 12 in the z-direction and has an upper edge (coinciding with the first edge 11A of the main surface 11) and a lower edge opposite to the upper edge. The first end surface 13 is inclined in the y-direction such that the upper edge is located closer to the center of the substrate 1 than the lower edge. Furthermore, the first end surface 13 is exposed from the resistive layer 3 and the wiring layer 4. Therefore, in the manufacturing process of the thermal printhead A10, the step of cutting the substrate 81 (substrate 1) in the z-direction (see...) Figure 19In the thermal printhead A10, the substrate 81 is cut off at least at a position away from the main surface 11. Therefore, no breakage occurs at the peripheral edge of the main surface 11 (the first edge 11A in the thermal printhead A10). Thus, the thermal printhead A10 according to the present invention can prevent damage to the wiring layer 4 caused by breakage of the substrate 1 that occurs during the manufacturing of the thermal printhead A10.

[0153] In the manufacturing process of the thermal printhead A10, it went through... Figure 16 The step shown is performed after the groove 811 is formed on the substrate 81. Figure 19 The step shown is cutting the substrate 81 in the z-direction. The groove 811 has an inclined surface 811B relative to the main surface 11. Therefore, the external force in the z-direction acting on the peripheral edge of the main surface 11 when forming the groove 811 is reduced, thus allowing the groove 811 to be formed in the substrate 81 without damage. Furthermore, in the step of cutting the substrate 81 in the z-direction, as... Figure 20 The cutting line CL of the substrate 81 is set in such a way that it passes through the groove 811, thereby enabling the substrate 81 to be cut without damage to the periphery of the main surface 11.

[0154] In the manufacturing process of the thermal printhead A10, the step of forming the groove 811 in the substrate 81 (see...) Figure 16 In this process, a groove 811 is formed using a first blade 87. The first blade 87 has a base 871 and a tip 872. The thickness t2 of the tip 872 decreases as it moves further away from the base 871 in the radial direction of the first blade 87. As a result, a groove 811 with an inclined surface 811B can be formed in the substrate 81.

[0155] In the manufacturing process of the thermal printhead A10, the step of cutting the substrate 81 in the z-direction (see...) Figure 19 In this process, a second blade 88 is used to cut the substrate 81. The thickness t3 of the second blade 88 is smaller than the thickness t1 of the base 871 of the first blade 87. As a result, the second blade 88 can cut the substrate 81 without contacting the peripheral edge of the main surface 11 of the substrate 81.

[0156] The substrate 1 has a second end face 14 connected to the back surface 12. The second end face 14 is located on the opposite side of the main surface 11 relative to the first end face 13 in a direction orthogonal to the z-direction. The second end face 14 is exposed from the resistive layer 3 and the wiring layer 4. Furthermore, the tilt angle β1 of the first end face 13 relative to the main surface 11 is smaller than the tilt angle β2 of the second end face 14 relative to the back surface 12. Therefore, it is possible to suppress the dimensional expansion of the substrate 1 having the first end face 13.

[0157] The substrate 1 has a middle surface 15 facing the z-direction and connected to the first end surface 13 and the second end surface 14. The middle surface 15 is exposed from the resistive layer 3 and the wiring layer 4. Thus, in the manufacturing process of the thermal printhead A10, in the step of cutting the substrate 81 in the z-direction (see...) Figure 19 In this process, the substrate 81 is cut off at a position away from the main surface 11 and the first end surface 13. Therefore, it is possible to more reliably prevent damage at the periphery of the main surface 11.

[0158] The substrate 1 is formed of a semiconductor material. This semiconductor material comprises a single-crystal material composed of silicon. This allows for a relatively high thermal conductivity of the substrate 1 (approximately 170 W / (m·K)) and reduces the cost of the substrate 1. The substrate 1 having a first end face 13 is particularly advantageous in preventing breakage of the substrate 1 formed from such a material.

[0159] The substrate 1 has a protrusion 19 protruding from the main surface 11 in the z-direction. Multiple heating elements 31 of the resistive layer 3 are formed on the protrusion 19. Thus, in... Figure 4 When printing onto the recording medium 78, the contact area between the recording medium 78 and the thermal printhead A10 can be minimized, and heat from the multiple heating elements 31 can be conducted to the recording medium 78. This improves the printing quality onto the recording medium 78.

[0160] The thermal printhead A10 also has a protective layer 5 covering the multiple heating elements 31 of the resistive layer 3 and the wiring layer 4. As a result, the multiple heating elements 31 and the wiring layer 4 are protected by the protective layer 5, and the contact between the recording medium 78 and the thermal printhead A10 becomes smoother when the thermal printhead A10 is in use.

[0161] The thermal printhead A10 also has a heat dissipation component 72. The back side 12 of the substrate 1 is bonded to the heat dissipation component 72. Thus, when the thermal printhead A10 is in use, a portion of the heat emitted from the multiple heat-generating parts 31 can be rapidly released to the outside via the substrate 1 and the heat dissipation component 72.

[0162] [Second Implementation]

[0163] based on Figures 24-27 The thermal printhead A20 of the second embodiment of the present invention will be described here. In these figures, elements that are the same as or similar to those in the previously described thermal printhead A10 are labeled with the same reference numerals, and repeated descriptions are omitted. Figure 24 For easier understanding, protective layer 5 is shown in the image.

[0164] In the thermal printhead A20, the structure of the substrate 1 is different from that of the previously described thermal printhead A10.

[0165] like Figure 24 As shown, the first end face 13 of the substrate 1 includes a first region 131 and a second region 132. The first region 131 is connected to the first edge 11A of the main surface 11 of the substrate 1. The second region 132 is connected to the second edge 11B of the main surface 11 and the first region 131. The second end face 14 of the substrate 1 includes a third region 141 and a fourth region 142. The third region 141 extends in the x-direction. The fourth region 142 extends in the y-direction and is connected to the third region 141.

[0166] like Figure 24 As shown, the first region 131 is inclined at an angle β1 relative to the main surface 11. Figure 25 As shown, the second region 132 is tilted relative to the main surface 11 at an angle β1. Therefore, in the thermal printhead A20, the tilt angle of the second region 132 relative to the main surface 11 is equal to the tilt angle of the first region 131 relative to the main surface 11. However, the tilt angle of the second region 132 relative to the main surface 11 may also be different from the tilt angle of the first region 131 relative to the main surface 11.

[0167] like Figure 24 As shown, substrate 1 has a ridge line 16. The ridge line 16 forms the boundary between the first region 131 and the second region 132. Figure 27 As shown, edge 16 is inclined at an angle γ relative to the principal face 11. The angle γ is more inclined than... Figure 25 and Figure 26 The first end face 13 shown has a small inclination angle β1 relative to the main face 11.

[0168] In the thermal printhead A20, similarly to the previously described thermal printhead A11, it can also be formed such that the substrate 1 does not have a middle surface 15 (see reference). Figure 21 In the thermal printhead A20, similarly to the previously described thermal printhead A12, the substrate 1 can also be formed without the second end face 14 and the intermediate face 15 (see reference). Figure 22 Furthermore, in the thermal printhead A20, the end face 52 of the protective layer 5 can also be formed with the same structure as the previously described thermal printhead A13 (see reference). Figure 23 ).

[0169] Next, the function and effect of the thermal printhead A20 will be explained.

[0170] The thermal printhead A20 has a substrate 1 having a main surface 11 and a back surface 12 facing opposite sides in the z-direction, and a first end surface 13 connected to the main surface 11. The first end surface 13 overlaps with the back surface 12 when viewed in the z-direction and is inclined relative to the main surface 11 in the same manner as the first end surface 13 of the thermal printhead A10 described above. The first end surface 13 is exposed from the resistive layer 3 and the wiring layer 4. Therefore, according to the thermal printhead A20, damage to the wiring layer 4 caused by breakage of the substrate 1 during the manufacturing of the thermal printhead A20 can be prevented.

[0171] The main surface 11 of the substrate 1 includes a first edge 11A extending in the x-direction and located closest to the resistive layer 3, and a second edge 11B extending in the y-direction. In the thermal printhead A20, the first end surface 13 of the substrate 1 includes a first region 131 connected to the first edge 11A and a second region 132 connected to the second edge 11B. Thus, in the manufacturing process of the thermal printhead A20, the step of cutting the substrate 81 (substrate 1) in the z-direction (see...) Figure 19 In this system, it is possible to prevent damage to both the first edge 11A extending in the x direction and the second edge 11B extending in the y direction.

[0172] The substrate 1 has an edge 16 forming the boundary between the first region 131 and the second region 132. The edge 16 is inclined relative to the main surface 11 of the substrate 1. This prevents breakage at the peripheral edge located at the corner of the main surface 11. In this case, the inclination angle γ of the edge 16 relative to the main surface 11 is smaller than the inclination angle β1 of the first end face 13 relative to the main surface 11, thus more effectively preventing breakage. Therefore, this structure is optimal in preventing breakage of the substrate 1.

[0173] This invention is not limited to the embodiments described above. Various design changes can be made to the specific structure of each part of this invention.

[0174] As described above, according to the present invention, a thermal printhead and a method for manufacturing the same can be provided. The present invention includes the embodiments described in the following appendix.

[0175] [Postscript 1]

[0176] A thermal printhead, characterized in that it comprises:

[0177] A substrate having a main surface and a back surface facing opposite sides in the thickness direction, and a first end surface connected to the main surface;

[0178] A resistive layer comprising a plurality of heating elements arranged in the main scanning direction, and at least a portion thereof formed on the main surface; and

[0179] A wiring layer, which is electrically connected to the plurality of heating elements and is formed in contact with the resistive layer, is provided.

[0180] The first end face is inclined relative to the main face in such a way that it overlaps with the back face when viewed in the thickness direction.

[0181] The first end face is exposed from the resistive layer and the wiring layer.

[0182] [Postscript 2]

[0183] As described in Appendix 1, the main surface of the thermal printhead includes: a first edge extending in the main scanning direction and located closest to the resistive layer; and a second edge extending in the sub-scanning direction.

[0184] The first end face includes: a first region connected to the first edge; and a second region connected to the second edge.

[0185] [Postscript 3]

[0186] As described in Appendix 2, the thermal printhead

[0187] The substrate has an edge that forms the boundary between the first region and the second region.

[0188] The edge is inclined relative to the main face.

[0189] [Postscript 4]

[0190] As described in Appendix 3, the thermal printhead

[0191] The angle of inclination of the edge relative to the main face is smaller than the angle of inclination of the first end face relative to the main face.

[0192] [Postscript 5]

[0193] Thermal printheads as described in any of the notes 1 to 4

[0194] The substrate has a second end face that is connected to the back side.

[0195] The second end face is located on the opposite side of the main face relative to the first end face in a direction orthogonal to the thickness direction.

[0196] The second end face is exposed from the resistive layer and the wiring layer.

[0197] [Postscript 6]

[0198] As described in Appendix 5, the thermal printhead

[0199] The tilt angle of the first end face relative to the main face is smaller than the tilt angle of the second end face relative to the back face.

[0200] [Postscript 7]

[0201] As described in Appendix 6, the thermal printhead

[0202] The substrate has a middle surface facing the thickness direction and connected to the first end face and the second end face.

[0203] The intermediate surface is exposed from the resistive layer and the wiring layer.

[0204] [Postscript 8]

[0205] As described in Appendix 6, the thermal printhead

[0206] The second end face is connected to the first end face.

[0207] [Postscript 9]

[0208] Thermal printheads as described in any of the notes 1 to 8

[0209] The substrate is formed of a semiconductor material.

[0210] The semiconductor material comprises a single-crystal material composed of silicon.

[0211] [Postscript 10]

[0212] As described in Appendix 9, the thermal printhead

[0213] The substrate has a protrusion that projects from the main surface in the thickness direction.

[0214] The plurality of heating elements are formed on the protrusion.

[0215] [Postscript 11]

[0216] As described in Appendix 9 or 10, thermal printheads

[0217] It also includes an insulating layer covering the main surface.

[0218] The insulating layer is located between the substrate and the resistive layer.

[0219] The first end face is exposed from the insulating layer.

[0220] [Postscript 12]

[0221] The thermal printhead described in any of the notes 1 to 11

[0222] The wiring layer includes common wiring and multiple individual wirings.

[0223] The common wiring is connected to the plurality of heating elements.

[0224] Each of the multiple individual wirings is individually connected to each of the multiple heat-generating components.

[0225] [Postscript 13]

[0226] The thermal printhead described in any of the notes 1 to 12

[0227] It also includes a protective layer covering the plurality of heating elements and the wiring layer.

[0228] The first end face is exposed from the protective layer.

[0229] [Postscript 14]

[0230] As described in any of the notes 1 to 13, thermal printheads

[0231] It also includes heat dissipation components,

[0232] The back side is attached to the heat dissipation component.

[0233] [Postscript 15]

[0234] A method for manufacturing a thermal printhead, comprising:

[0235] The step of forming a resistive layer containing a plurality of heating elements arranged in the main scanning direction on a substrate having a main surface facing the thickness direction;

[0236] The steps of forming a wiring layer that is conductive to the plurality of heating elements in a manner that contacts the resistive layer; and

[0237] The step of cutting the substrate in the thickness direction

[0238] Between the step of forming the wiring layer and the step of cutting the substrate, the method further includes a step of forming a groove on the substrate that is recessed from the main surface and extends in a direction orthogonal to the thickness direction.

[0239] The groove has an inclined surface that is connected to the main surface and inclined relative to the main surface.

[0240] In the step of cutting the substrate, the cutting line of the substrate passes through the groove.

[0241] [Postscript 16]

[0242] The manufacturing method of the thermal printhead is described in Appendix 15.

[0243] In the step of forming the groove, a first blade is used to form the groove.

[0244] The first blade has a base and a tip, the tip extending radially from the base and surrounding the base circumferentially.

[0245] The thickness of the blade tip gradually decreases as it moves further away from the base in the radial direction.

[0246] [Postscript 17]

[0247] The manufacturing method of the thermal printhead is described in Appendix 16.

[0248] In the step of cutting the substrate, a second blade is used to cut the substrate.

[0249] The thickness of the second blade is smaller than the thickness of the base.

Claims

1. A thermal printhead, characterized in that, include: A substrate having a main surface and a back surface facing opposite sides in the thickness direction, and a first end surface connected to the main surface and a second end surface connected to the back surface; A resistive layer comprising a plurality of heating elements arranged in the main scanning direction, and at least a portion thereof formed on the main surface; and A wiring layer, which is electrically connected to the plurality of heating elements and is formed in contact with the resistive layer, is provided. The first end face and the second end face are respectively located between the main face and the back face in the thickness direction. The first end face overlaps with the back face when viewed in the thickness direction. The second end face is located on the opposite side of the main face relative to the first end face in a direction orthogonal to the thickness direction. The first end face is inclined relative to the main face on the side where the second end face is located in a direction orthogonal to the thickness direction. The inclination angle of the first end face relative to the main face is smaller than the inclination angle of the second end face relative to the back face. The substrate has a middle surface facing the thickness direction and connected to the first end face and the second end face. Viewed in the thickness direction, the first end face, the second end face, and the intermediate face are separated from the resistive layer and the wiring layer, respectively.

2. The thermal printhead as described in claim 1, characterized in that: The main surface includes: a first edge extending in the main scanning direction and located closest to the resistive layer; and a second edge extending in the sub-scanning direction. The first end face includes: a first region connected to the first edge; and a second region connected to the second edge.

3. The thermal printhead as described in claim 2, characterized in that: The substrate has an edge that forms the boundary between the first region and the second region. The edge is inclined relative to the main face.

4. The thermal printhead as described in claim 3, characterized in that: The angle of inclination of the edge relative to the main face is smaller than the angle of inclination of the first end face relative to the main face.

5. The thermal printhead as described in claim 1, characterized in that: The substrate is formed of a semiconductor material. The semiconductor material comprises a single-crystal material composed of silicon.

6. The thermal printhead as described in claim 5, characterized in that: The substrate has a protrusion that projects from the main surface in the thickness direction. The plurality of heating elements are formed on the protrusion.

7. The thermal printhead as described in claim 5, characterized in that: It also includes an insulating layer covering the main surface. The insulating layer is located between the substrate and the resistive layer. Viewed in the thickness direction, the insulating layer overlaps entirely with the main surface.

8. The thermal printhead as described in claim 7, characterized in that: The wiring layer includes common wiring and multiple individual wirings. The common wiring is connected to the plurality of heating elements. Each of the multiple individual wirings is individually connected to each of the multiple heat-generating components.

9. The thermal printhead as described in claim 7, characterized in that: It also includes a protective layer covering the plurality of heating elements and the wiring layer. Viewed in the thickness direction, the protective layer overlaps entirely with the main surface.

10. The thermal printhead as described in claim 9, characterized in that: The protective layer has an end face facing a direction orthogonal to the thickness direction. Viewed in the thickness direction, the end face is separated from the periphery of the insulation layer on the side where the wiring layer is located, which is closer to the periphery of the insulation layer than the periphery of the insulation layer.

11. The thermal printhead as described in any one of claims 1 to 10, characterized in that: It also includes heat dissipation components, The back side is attached to the heat dissipation component.

12. A method for manufacturing a thermal printhead, characterized in that, include: The step of forming a resistive layer containing a plurality of heating elements arranged in the main scanning direction on a substrate having a main surface facing one side toward the thickness direction; The step of forming a wiring layer that is conductive to the plurality of heating elements in a manner that contacts the resistive layer; The step of forming a groove on the substrate, wherein the groove is recessed from the main surface and extends along a direction orthogonal to the thickness direction, and is separated from the resistive layer and the wiring layer, respectively; and The step of cutting the substrate in the thickness direction The groove has: an inclined surface connected to the main surface and inclined relative to the main surface; and a bottom surface facing the same side as the main surface in the thickness direction, and located on the opposite side of the main surface relative to the inclined surface in a direction orthogonal to the thickness direction. In the step of forming the groove, a first blade is used to form the groove. The first blade has a base and a tip, the tip extending radially from the base and surrounding the base circumferentially. The thickness of the blade tip gradually decreases as it moves further away from the base in the radial direction. The blade tip has an end face facing the radial direction. In the step of cutting the substrate, a second blade is used to cut the substrate. The thickness of the second blade is smaller than the dimension of the end face in the direction orthogonal to the radial direction. In the step of cutting the substrate, the second blade is separated from the inclined surface and the second blade is brought into contact with the bottom surface.

Images