CN114379246A - Thermal print head and method of manufacturing thermal print head - Google Patents

Abstract

The invention provides a thermal print head which is easier to manufacture and a manufacturing method of the thermal print head. A thermal print head includes: the semiconductor device includes a substrate (1) including a base material (10) made of a single crystal semiconductor, a resistor layer (4) supported on the substrate (1) and having a plurality of heat generating portions (41) arranged in a main scanning direction (X), and a wiring layer (3) supported on the substrate (1) and constituting a current conducting path to the plurality of heat generating portions (41), wherein the wiring layer (3) is in contact with the substrate (1), and the resistor layer (4) has a portion overlapping the wiring layer (3) from a side opposite to the substrate (1) in a thickness direction (z).

Description

Thermal print head and method of manufacturing thermal print head

Technical Field

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

Background

A thermal print head is a device for realizing a main function of a thermal printer for printing on a printing object such as thermal paper. Patent document 1 discloses a conventional example of a thermal print head. The thermal print head disclosed in this document includes a substrate, a resistor layer, and a wiring layer. The substrate includes a base material composed of a semiconductor single crystal. The resistor layer is formed directly on the substrate. The wiring layer is formed on the resistor layer.

Patent document 1: japanese patent laid-open publication No. 2017-114051

Disclosure of Invention

Problems to be solved by the invention

The resistor layer and the wiring layer are formed by thin film formation methods such as sputtering and CVD. In this case, the resistor layer is formed between all the portions of the wiring layer and the substrate. Generally, after that, a wiring pattern is formed by applying a photolithography technique in the wiring layer, and a resistor body pattern is formed by applying a photolithography technique in the resistor layer. The resistor pattern includes a plurality of heat generating portions. Each lithography technique includes the respective processes of gumming, soft baking, exposure, development, rinsing, post baking, etching, and resist removal.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a thermal print head which can be manufactured more easily, and a method of manufacturing the thermal print head.

Means for solving the problems

A first aspect of the present invention provides a thermal print head comprising: a substrate including a base material made of a single crystal semiconductor; a resistor layer having a plurality of heat generating portions supported by the substrate and arranged in a main scanning direction; and a wiring layer supported by the substrate and constituting a current-carrying path to the plurality of heat generating portions, the wiring layer being in contact with the substrate, and the resistor layer having a portion overlapping the wiring layer from an opposite side of the substrate in a thickness direction.

A second aspect of the present invention provides a method of manufacturing a thermal print head, including: preparing a substrate including a base material made of a single crystal semiconductor; forming a wiring layer supported by the substrate; and a step of forming the wiring layer, wherein the step of forming the wiring layer includes a conductive film forming process using sputtering or CVD, and the step of forming the resistor layer includes a process of applying a resistor paste and a process of firing the resistor paste.

Effects of the invention

According to the present invention, the thermal head can be manufactured more easily.

Other features and advantages of the present invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying drawings.

Drawings

Fig. 1 is a plan view showing a thermal head according to embodiment 1 of the present invention.

Fig. 2 is an enlarged plan view of a principal part of a part of the plan view shown in fig. 1.

Fig. 3 is an enlarged plan view of a main portion of a part of the plan view shown in fig. 2.

Fig. 4 is a partially enlarged sectional view of a thermal printer including the thermal head according to embodiment 1, and is a sectional view taken along line IV-IV of fig. 1.

Fig. 5 is an enlarged sectional view of a main portion of a part of the sectional view shown in fig. 4.

Fig. 6 is an enlarged sectional view of a main portion of a part of the sectional view shown in fig. 5.

Fig. 7 is a flowchart showing an example of a method of manufacturing a thermal head according to embodiment 1 of the present invention.

Fig. 8 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to embodiment 1 of the present invention.

Fig. 9 is a sectional view of a principal part showing a step of a method of manufacturing a thermal head according to embodiment 1 of the present invention.

Fig. 10 is a sectional view of a main part showing a step of a method of manufacturing a thermal head according to embodiment 1 of the present invention.

Fig. 11 is an enlarged sectional view of a main part showing a step of a method of manufacturing a thermal head according to embodiment 1 of the present invention.

Fig. 12 is an enlarged plan view of a principal part showing a step of a method of manufacturing a thermal head according to embodiment 1 of the present invention.

Fig. 13 is an enlarged sectional view of a main portion taken along line XIII-XIII in fig. 12.

Fig. 14 is an enlarged plan view of a principal part showing a step of a method of manufacturing a thermal head according to embodiment 1 of the present invention.

Fig. 15 is an enlarged sectional view of a main portion along the XV-XV line of fig. 14.

Fig. 16 is an enlarged plan view of a principal part showing a step of a method of manufacturing a thermal head according to embodiment 1 of the present invention.

Fig. 17 is an enlarged sectional view of a main portion along the line XVII-XVII of fig. 16.

Fig. 18 is an enlarged plan view of a principal part showing a step of a method of manufacturing a thermal head according to embodiment 1 of the present invention.

Fig. 19 is an enlarged sectional view of a main portion along XIX-XIX line of fig. 18.

Fig. 20 is an enlarged cross-sectional view of a main part showing a1 st modification of the thermal head according to embodiment 1 of the present invention.

Fig. 21 is a main-part enlarged plan view showing a thermal head according to embodiment 1 of modification 2 of the present invention.

Fig. 22 is an enlarged sectional view of a main portion along the line XXII-XXII of fig. 21.

Fig. 23 is an enlarged plan view of a main portion of a thermal head according to embodiment 2 of the present invention.

Fig. 24 is an enlarged plan view of a main portion of a thermal head according to embodiment 3 of the present invention.

Fig. 25 is a main-part enlarged plan view showing a thermal head according to embodiment 3 of the present invention according to modification 1.

Fig. 26 is a flowchart showing an example of a method of manufacturing a thermal head according to embodiment 3 of variation 1 of the present invention.

Fig. 27 is an enlarged cross-sectional view of a main portion of a thermal head according to embodiment 4 of the present invention.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Each figure is a schematic diagram. In addition, each drawing may sometimes include omitted parts and exaggerated parts.

The terms "first," "second," "third," and the like in this disclosure are used merely as labels, and are not intended to rank such objects.

< embodiment 1 >

Fig. 1 to 6 show a thermal head according to embodiment 1 of the present disclosure. The thermal head a1 of the present embodiment includes: substrate 1, protective layer 2, wiring layer 3, resistor layer 4, connection substrate 5, plurality of lines 61, 62, plurality of driver ICs 7, protective resin 78, and heat dissipation member 8. As shown in fig. 1 to 3, the plurality of heat generating portions 41 of the resistor layer 4 are arranged in a row. The direction in which the plurality of heat generating portions 41 are arranged is referred to as a main scanning direction x. A direction perpendicular to the main scanning direction x is referred to as a sub-scanning direction y. The thermal head a1 is incorporated into a thermal printer Pr (see fig. 4) that prints on a print target (not shown). The thermal printer Pr includes a thermal head a1 and a platen roller 91. The platen roller 91 is directly opposed to the thermal head a 1. The print target is sandwiched between the thermal head a1 and the platen roller 91, and is conveyed in the sub-scanning direction by the platen roller 91. Examples of such a printing object include a thermal paper used for creating a barcode table or a receipt. Instead of the platen roller 91, a platen made of flat rubber may be used. The platen includes a portion of cylindrical rubber having a large radius of curvature that is arcuate in cross section. In this disclosure, the term "platen" includes both a platen roller 91 and a flat platen.

Fig. 1 is a plan view showing a thermal head a 1. Fig. 2 is an enlarged plan view of a principal part of a part of the plan view shown in fig. 1. Fig. 3 is an enlarged plan view of a main portion of a part of the plan view shown in fig. 2. Fig. 4 is a partially enlarged sectional view of the thermal printer including the thermal head a1, which is a sectional view taken along line IV-IV of fig. 1. Fig. 5 is an enlarged sectional view of a main portion of a part of the sectional view shown in fig. 4. Fig. 6 is an enlarged sectional view of a main portion of a part of the sectional view shown in fig. 5. The protective layer 2 is omitted in fig. 1 to 3. The protective resin 78 is omitted in fig. 1 and 2. The plurality of lines 61 are omitted in fig. 2. In the figure, the side indicated by the arrow indicating the coordinate axis in the sub-scanning direction y (the upper side in fig. 1) is referred to as the downstream side, and corresponds to the receiving side of the printing target. The side opposite to the downstream side in the sub-scanning direction y (the lower side in fig. 1) is referred to as the upstream side in the drawing, and corresponds to a provider of the printing object.

[ substrate 1]

The substrate 1 supports the wiring layer 3 and the resistor layer 4. The substrate 1 of the present embodiment includes a base 10 and an insulating layer 19.

The base material 10 is an elongated rectangle having a longitudinal direction in the main scanning direction x. In the following description, the thickness direction of the substrate 10 is referred to as a thickness direction z. The size of the substrate 10 is not particularly limited, but for example, the thickness (z-dimension in the thickness direction) is 725 μm, the x-dimension in the main scanning direction is 50mm to 150mm, and the y-dimension in the sub-scanning direction is 2.0mm to 5.0 mm.

The substrate 10 is made of a single crystal semiconductor, such as silicon (Si). As shown in fig. 4 and 5, the substrate 10 has a main surface 11 and a back surface 12. The main surface 11 and the back surface 12 are separated in the thickness direction z and face opposite sides to each other in the thickness direction z. The wiring layer 3 and the resistor layer 4 are provided on the main surface 11 side.

The base material 10 of the present embodiment has the convex portion 13. The convex portion 13 protrudes from the main surface 11 in the thickness direction z and extends in the main scanning direction x. In the illustrated example, the convex portion 13 is formed in the vicinity of the downstream of the base 10 in the sub-scanning direction y. Since the projection 13 is a part of the substrate 10, it is made of Si which is a crystalline semiconductor.

The convex portion 13 has a top portion 130, a pair of 1 st inclined portions 131A, 131B, and a pair of 2 nd inclined portions 132A, 132B.

The top 130 is the portion of the projection 13 that is the greatest distance from the main surface 11. The top 130 is, for example, a plane substantially parallel to the main surface 11. The top 130 is an elongated rectangle elongated in the main scanning direction x as viewed in the thickness direction z.

As shown in fig. 6, the pair of 1 st slope parts 131A, 131B are connected to both sides of the top part 130 in the sub-scanning direction y. The 1 st inclined part 131A is connected to the ceiling part 130 from the upstream side in the sub-scanning direction y. The 1 st inclined part 131B is connected to the ceiling part 130 from the downstream side in the sub-scanning direction y. The 1 st inclined part 131A corresponds to the "upstream side 1 st inclined part" in the claims, and the 1 st inclined part 131B corresponds to the "downstream side 1 st inclined part" in the claims. The pair of 1 st inclined portions 131A, 131B are inclined at only the angle α 1 (inclined at the 1 st inclination angle α 1) toward the main surface 11. The pair of 1 st inclined portions 131A, 131B are each a plane of an elongated rectangle elongated in the main scanning direction x as viewed in the thickness direction z. The convex portion 13 may be connected to the 1 st inclined portions 131A and 131B, and may have inclined portions (not shown) adjacent to both ends of the top portion 130 in the main scanning direction x.

As shown in fig. 6, the pair of 2 nd slope parts 132A, 132B are connected to the pair of 1 st slope parts 131A, 131B on the opposite side of the top part 130 in the sub-scanning direction y. The 2 nd inclined part 132A is sandwiched between the 1 st inclined part 131A and the main surface 11 in the sub-scanning direction y. The 2 nd inclined part 132A is connected to the 1 st inclined part 131A from the upstream side in the sub-scanning direction y, and is connected to the main surface 11 from the downstream side in the sub-scanning direction y. The 2 nd inclined part 132B is sandwiched between the 1 st inclined part 131B and the main surface 11 in the sub-scanning direction y. The 2 nd inclined part 132B is connected to the 1 st inclined part 131B from the downstream side in the sub-scanning direction y, and is connected to the main surface 11 from the upstream side in the sub-scanning direction y. The 2 nd inclined part 132A corresponds to the "upstream side 2 nd inclined part" described in the claims, and the 2 nd inclined part 132B corresponds to the "downstream side 2 nd inclined part" described in the claims. The pair of 2 nd inclined portions 132A, 132B are inclined at only the angle α 2 (inclined at the 2 nd inclination angle α 2) toward the principal surface 11. Angle α 2 is greater than angle α 1. The pair of 2 nd inclined portions 132A, 132B are each a plane of an elongated rectangle elongated in the main scanning direction x as viewed in the thickness direction z. The pair of 2 nd inclined portions 132A, 132B are connected to the main surface 11, respectively. The convex portion 13 may be connected to the pair of 2 nd inclined portions 132A and 132B, and may have inclined portions (not shown) located outside the main scanning direction x at both ends of the top portion 130 in the main scanning direction x.

In the substrate 10, the main surface 11 is a (100) surface. According to an example of a manufacturing method described later, an angle α 1 (see fig. 6) between each of the 1 st inclined portions 131A and 131B and the main surface 11 is, for example, 30.1 degrees, and an angle α 2 (see fig. 6) between each of the 2 nd inclined portions 132A and 132B and the main surface 11 is, for example, 54.7 degrees. The z-dimension of the projection 13 in the thickness direction is, for example, 150 to 300 μm.

As shown in fig. 5 and 6, the insulating layer 19 covers the principal surface 11 and the convex portion 13. The insulating layer 19 is used to further ensure insulation on the principal surface 11 side of the substrate 10. Insulation boardThe insulating layer 19 is made of an insulating material. As the insulating material, for example, SiO film-formed using TEOS (twinned ester) as a raw material gas is used₂(TEOS-SiO₂). Can also replace TEOS-SiO₂For example, SiO deposited by other methods₂Or SiN. The thickness of the insulating layer 19 is not particularly limited, but is, for example, 5 μm to 15 μm (preferably 5 μm to 10 μm).

[ Wiring layer 3]

The wiring layer 3 constitutes a current-carrying path for carrying current to a plurality of heat generating portions 41 of the resistor layer 4 described later. The wiring layer 3 is supported by the base material 10, and in the present embodiment, as shown in fig. 5 and 6, is directly laminated on the insulating layer 19.

The material and the laminated structure of the wiring layer 3 are not limited at all. For example, a case where the wiring layer 3 is formed of two layers, i.e., a lower layer and an upper layer (not shown) will be described as an example. As the constituent material of the lower layer, for example, Ti (titanium) is used, but Ta, Ga, Sn, PtIr, Pt, Ti (thallium), V (vanadium), Cr, or the like may be used instead of Ti. The method for forming the lower layer is not particularly limited, and the lower layer is formed by, for example, a spray method, a CVD method, plating, or the like, and is appropriately selected according to the constituent material used. For example, in the case where the constituent material of the lower layer is Ti, the lower layer is formed by a spray coating method. The thickness of the lower layer is not particularly limited, and is, for example, 0.1 μm or more and 0.2 μm or less.

The upper layer is formed on the lower layer. The constituent material of the upper layer is, for example, Cu, but Cu alloy, Al alloy, Au, Ag, Ni, W (tungsten), or the like may be used instead of Cu. The method for forming the upper layer is not particularly limited, and is formed by a method such as sputtering, CVD, or plating, and is appropriately selected according to the constituent material used. For example, in the case where the constituent material of the upper layer is Cu, the upper layer is formed by a sputtering method. In addition, when the constituent material of the upper layer is Au, Ag, Ni, the upper layer is generally formed by electroplating, but in this case, the upper layer may include a seed layer (e.g., Cu) or the like. The upper layer is thicker than the lower layer. The thickness of the upper layer depends on the material used, the value of the current flowing through the wiring layer 3, and the like. For example, the thickness of the upper layer is 0.5 μm or more and 5 μm or less.

As shown in fig. 3 and 6, the wiring layer 3 of the present embodiment includes a plurality of individual electrodes 32, a plurality of common electrodes 31, and a plurality of relay electrodes 33.

As shown in fig. 3, the individual electrodes 32 and the common electrodes 31 are arranged on the upstream side in the sub-scanning direction y with respect to the heat generating portions 41 of the resistor layer 4, which will be described later. The plurality of relay electrodes 33 are disposed downstream of the plurality of heat generating portions 41 in the sub-scanning direction y. The individual electrodes 32 and the common electrodes 31 are alternately arranged along the main scanning direction x. The plurality of relay electrodes 33 are arranged at a predetermined pitch in the main scanning direction x.

The common electrode 31 has a base portion 341 and a pair of 1 st strip portions 342. The pair of 1 st belt portions 342 are connected to a pair of heat generating portions 41 (a pair of 1 st heat generating portions 411 described later) adjacent in the main scanning direction x, and are arranged apart from each other in the main scanning direction x. The 1 st belt portion 342 is a belt shape extending in the sub-scanning direction y. The base portion 341 is connected to both of the pair of 1 st belt-shaped portions 342 and is located on the upstream side in the sub-scanning direction y. In this example, the top end of the 1 st band 342 is located on the top 130.

The individual electrode 32 has a2 nd stripe portion 345. The 2 nd band-shaped portion 345 is disposed at a position adjacent to the 1 st band-shaped portion 342 of the individual electrode 32 in the main scanning direction x, and is connected to the heat generating portion 41 (a 2 nd heat generating portion 412 described later). The 2 nd strip portion 345 is a strip extending in the sub-scanning direction y. In the present embodiment, a pair of 1 st strip portions 342 provided on one common electrode 31 are sandwiched, and a pair of 2 nd strip portions 345 are disposed on both sides in the main scanning direction x. In this example, the tip of the 2 nd band 345 is positioned on the apex 130, and the position of the tip of the 2 nd band 345 in the sub-scanning direction y is substantially the same as the position of the tip of the 1 st band 342.

The relay electrode 33 has a shape of a current carrying path that is folded back in the sub-scanning direction y. The relay electrode 33 is connected to a1 st heat generating portion 411 and a2 nd heat generating portion 412 which are adjacent to each other and described later. In this example, each relay electrode 33 is formed from the 1 st inclined portion 131B of the convex portion 13 across the 2 nd inclined portion 132B and the main surface 11. The tip of the relay electrode 33 on the upstream side in the sub-scanning direction y is positioned on the 1 st inclined part 131B.

[ resistor layer 4]

The resistor layer 4 is made of a material having a resistivity higher than that of the material constituting the wiring layer 3. The resistor layer 4 is made of, for example, ruthenium oxide. The position of formation of the resistor layer 4 in this example is not limited at all, and in this example, as shown in fig. 3 and 6, the resistor layer is formed on the top 130 of the convex portion 13 and the 1 st inclined portion 131B. The thickness of the resistor layer 4 is, for example, 3 μm to 6 μm. The material and thickness of the resistor layer 4 are not limited. In this example, the thickness of the resistor layer 4 is larger than that of the wiring layer 3. The resistor layer 4 has a plurality of heat generating portions 41. The shape of the heat generating portion 41 is not limited at all, and is, for example, a long rectangular shape having the sub-scanning direction y as a longitudinal direction. The method of forming the resistor layer 4 is not limited at all, and in the present embodiment, as described later, a resistor film is obtained by applying a paste containing ruthenium oxide and firing the paste. By removing a predetermined portion of the resistor film, the resistor layer 4 including the plurality of heat generating portions 41 (the 1 st heat generating portion 411 and the 2 nd heat generating portion 412) is obtained.

The plurality of heat generating portions 41 are arranged apart from each other in the main scanning direction x. The plurality of heat generating portions include a1 st heat generating portion 411 and a2 nd heat generating portion 412. In the illustrated example, the pair of 1 st heat generating portions 411 are arranged to be spaced apart in the main scanning direction x. Further, a pair of 2 nd heat generating portions 412 are arranged on both sides in the main scanning direction x with the pair of 1 st heat generating portions 411 interposed therebetween. A plurality of sets of the pair of 1 st heat generating portions 411 and the pair of 2 nd heat generating portions 412 are arranged in the main scanning direction x.

The 1 st heat generating portion 411 overlaps with the tip portion of the 1 st strip portion 342 and the tip portion of one of the relay electrodes 33, respectively. That is, the 1 st heat generating portion 411 has a portion directly contacting the substrate 1 (insulating layer 19) and a portion overlapping the 1 st strip portion 342 and the relay electrode 33 from the opposite side of the substrate 1 in the thickness direction z. Therefore, the dimension along the sub-scanning direction y of the 1 st heat generating portion 411 is larger than the distance between the tip of the 1 st strip portion 342 and the tip of the relay electrode 33.

The 2 nd heat generating portion 412 overlaps with the tip portion of the 2 nd band-like portion 345 and the other tip portion of the relay electrode 33, respectively. That is, the 2 nd heat generating portion 412 has a portion directly contacting the substrate 1 (insulating layer 19) and a portion overlapping the 2 nd band-shaped portion 345 and the relay electrode 33 from the opposite side of the substrate 1 in the thickness direction z. Therefore, the dimension along the sub-scanning direction y of the 2 nd heat generating portion 412 is larger than the distance between the tip of the 2 nd band-shaped portion 345 and the tip of the relay electrode 33.

When current is supplied to one of the individual electrodes 32, the current flows through a conduction path formed by the 2 nd strip 345, the 2 nd heat generating portion 412, the relay electrode 33, the 1 st heat generating portion 411, and the 1 st strip 342. Thereby, the 1 st and 2 nd heat generation portions 411, 412 adjacent to each other generate heat. That is, in the thermal head a1 of the present embodiment, one heat generating portion 411 and one heat generating portion 2 that are adjacent to each other constitute one printing dot (one dot formed on the printing object). As explained with reference to fig. 3, for example, one printing dot is constituted by the 4 th 1 st heat generating portion 411 from the left and the 3 rd 2 nd heat generating portion 412 from the left.

[ protective layer 2]

The protective layer 2 covers the wiring layer 3 and the resistor layer 4, and protects the wiring layer 3 and the resistor layer 4. The protective layer 2 is made of an insulating material. As the insulating material, for example, SiN (silicon nitride) is used, but SiO (silicon oxide) may be used₂Instead of SiN, (silicon oxide), SiC (silicon carbide), AlN (aluminum nitride), or the like, the protective layer 2 is composed of a single layer or a plurality of layers including the above-described insulating material. The thickness of the protective layer 2 is not particularly limited, but is, for example, 1.0 μm or more and 10 μm or less.

As shown in fig. 5, the protective layer 2 has a plurality of pad openings 21. Each of the pad openings 21 penetrates the protective layer 2 in the thickness direction z. The plurality of pad openings 21 expose the individual pads 321 of the respective electrodes 32. Unlike the illustrated example, the plurality of pad openings 21 may be filled with a conductive material. In this case, a plating layer may be formed on the conductive material. The structure of the plating layer is not particularly limited, and examples thereof include Ni, Pd (palladium), and Au laminated in this order from the surface of the conductive material

[ connection substrate 5]

As shown in fig. 1 and 4, the connection substrate 5 is disposed on the upstream side in the sub-scanning direction y. The connection substrate 5 is, for example, a PCB substrate, and mounts the driver IC7 and a connector 59 described later. The shape and the like of the connection substrate 5 are not particularly limited, but in the present embodiment, the connection substrate is a rectangle whose longitudinal direction is the main scanning direction x. The connection substrate 5 has a main surface 51 and a back surface 52. The main surface 51 is a surface facing the same side as the main surface 11 of the substrate 10, and the back surface 52 is a surface facing the same side as the back surface 12 of the substrate 10. In the present embodiment, the main surface 51 is located lower in the thickness direction z than the main surface 11.

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

[ driver IC7]

The driver IC7 is mounted on the main surface 51 of the connection substrate 5 and individually supplies current to the plurality of heat generating portions 41. The plurality of driver ICs 7 are connected to the plurality of individual electrodes 32 via the plurality of lines 61. The control of the energization of the plurality of heat generating portions 41 by the plurality of driver ICs 7 is performed in accordance with a command signal input from the outside of the thermal head a1 via the connection substrate 5. The driver ICs 7 are connected to a wiring pattern (not shown) of the connection substrate 5 via a plurality of lines 62. The plurality of driver ICs 7 are provided as appropriate in accordance with the number of the plurality of heat generating portions 41.

[ protective resin 78]

The protective resin 78 covers the plurality of driver ICs 7, the plurality of lines 61, and the plurality of lines 62. The protective resin 78 is made of an insulating resin such as epoxy resin, and is black, for example. The protective resin 78 is formed so as to straddle the substrate 1 and the connection substrate 5.

[ Heat-dissipating Member 8]

The heat dissipation member 8 supports the substrate 1 and the connection substrate 5, and dissipates part of the heat generated by the plurality of heat generation portions 41 to the outside through the base 10 of the substrate 1. The heat dissipation member 8 is a block member made of metal such as Al, for example. The heat dissipation member 8 has a1 st support surface 81 and a2 nd support surface 82. The 1 st support surface 81 and the 2 nd support surface 82 are respectively arranged facing upward in the thickness direction z and aligned in the sub-scanning direction y. The back surface 12 of the substrate 10 is bonded to the 1 st supporting surface 81. The back surface 52 of the connection substrate 5 is joined to the 2 nd supporting surface 82.

Next, an example of a method for manufacturing the thermal head a1 will be described with reference to fig. 7 to 19.

Fig. 7 is a flowchart showing an example of a method of manufacturing the thermal head a 1. As shown in the drawing, the method of manufacturing the thermal head a1 according to the present embodiment includes a substrate preparation step, a wiring layer formation step, a resistor layer formation step, and a protective layer formation step.

[ substrate preparation Process ]

First, as shown in fig. 8, a substrate material 1K is prepared. The substrate material 1K is made of a single crystal semiconductor, and is, for example, a part of a substantially circular silicon wafer. One silicon wafer contains a plurality of substrate materials 1K. In the following drawings, a part of a silicon wafer and one substrate material 1K (base material 10) corresponding to one thermal head a1 are illustrated in some cases. The thickness of the substrate material 1K (in other words, the thickness of the silicon wafer) is not particularly limited, but is, for example, about 725 μm in the present embodiment. The substrate material 1K has a main surface 11K and a back surface 12K facing opposite sides to each other. The main surface 11K is a (100) surface.

Next, after covering the main surface 11K with a predetermined mask layer, anisotropic etching is performed using, for example, KOH. The mask layer is then removed. Then, as shown in fig. 9, the convex portion 13K is formed on the substrate material 1K. The convex portion 13K protrudes from the main surface 11K and extends in the main scanning direction x. The convex portion 13K has a top portion 130K and a pair of inclined portions 132K. The top 130K is a plane parallel to the main surface 11K and is the same (100) plane as the main surface 11K. The pair of inclined portions 132K are located on both sides of the apex portion 130K in the sub-scanning direction y, and are interposed between the apex portion 130K and the main surface 11K. The pair of inclined portions 132K are planes inclined with respect to the top portion 130K and the main surface 11K, respectively. The angle formed by the pair of inclined portions 132K with the main surface 11K and the top portion 130K is 54.7 degrees.

Next, after removing the mask layer, anisotropic etching is performed using, for example, TMAH (trimethyl ammonium hydroxide). Then, as shown in fig. 10, the substrate material 1K becomes a base material 10 having a main surface 11, a back surface 12, and a convex portion 13. The convex portion 13 has a top portion 130, a pair of 1 st inclined portions 131A, 131B, and a pair of 2 nd inclined portions 132A, 132B. The top 130 is a portion of the top 130K, and the pair of 2 nd inclined portions 132A, 132B are portions of the pair of inclined portions 132K. The pair of 1 st inclined portions 131A and 131B are portions where the boundary between the top portion 130K and the pair of inclined portions 132K is etched by TMAH. An angle α 1 (see fig. 6 and 10) between each of the 1 st inclined portions 131A and 131B and the main surface 11 is 30.1 degrees, and an angle α 2 (see fig. 6 and 10) between each of the 2 nd inclined portions 132A and 132B and the main surface 11 is 54.7 degrees.

Next, the insulating layer 19 is formed as shown in fig. 11. For example, SiO formed by depositing TEOS (di-crystal acid ester) as a raw material gas on the substrate 10 by using a CVD method₂Thereby forming the insulating layer 19. The method of forming the insulating layer 19 is not limited to this. Through the above steps, the substrate 1 having the base 10 and the insulating layer 19 is obtained.

[ Wiring layer Forming Process ]

The wiring layer forming process includes a conductive film forming process and a conductive film patterning process.

(conductive film formation treatment)

Next, as shown in fig. 12 and 13, a conductive film 3K is formed. In the step of forming the conductive film 3K, for example, the lower layer and the upper layer are formed in this order. In the step of forming the lower layer, a thin film of Ti is formed on the insulating layer 19 of the substrate 1 by sputtering, for example. At this time, the lower layer covers substantially the entire substrate 1. In the step of forming the upper layer, a layer made of Cu is formed on the lower layer by, for example, plating, sputtering, or the like. In this case, the upper layer covers substantially the entire lower layer.

(conductive film patterning treatment)

Next, a conductive film patterning process of partially removing the conductive film 3K is performed. The conductive film patterning process is performed, for example, by mask making using a photolithography method and etching using the mask. As a result, as shown in fig. 14 and 15, the wiring layer 3 including the plurality of common electrodes 31, the plurality of individual electrodes 32, and the plurality of relay electrodes 33 is obtained.

[ resistor layer Forming Process ]

The resistor layer forming process includes a resistor paste application process, a resistor paste firing process, and a resistor film removal process.

(resistor paste application treatment)

As shown in fig. 16 and 17, a resistor paste containing ruthenium oxide is applied to the substrate 1 by thick-film printing or the like. At this time, the resistor paste is coated on a belt shape extending in the main scanning direction x. The resistor paste is applied so as to overlap with the tip portions of the 1 st and 2 nd strip portions 342 and 345 on the downstream side in the sub-scanning direction y and the tip portions of the relay electrodes 33 on the upstream side in the sub-scanning direction y. The dimension of the band-shaped resistor paste in the sub-scanning direction y is larger than the distances between the 1 st and 2 nd band-shaped portions 342 and 345 and the relay electrode 33 in the sub-scanning direction y. Alternatively, the resistor paste may be sprayed onto the substrate 1 using a separator.

(sintering treatment of resistor paste)

Next, the resistor paste is dried and then cured by firing the resistor paste. Thereby, the cured resistor film 4K shown in fig. 16 and 17 was obtained. The resistor film 4K is located on the top 130 and the 1 st inclined portion 131B of the convex portion 13, and overlaps with the 1 st strip portion 342 of the plurality of common electrodes 31, the 2 nd strip portion 345 of the plurality of individual electrodes 32, and a part of the plurality of relay electrodes 33, respectively.

(resistor film removal treatment)

Then, a part of the cured resistor film 40 is removed. In this removal process, as shown in fig. 16, a plurality of removal regions 49K are set in the resistor film 4K, and these removal regions 49K are removed. The removal region 49K is an elongated strip-like or linear region extending in the sub-scanning direction y between the 1 st strip-like portions 342 adjacent in the main scanning direction x or between the 1 st strip-like portions 342 and the 2 nd strip-like portions 345. The removed region 49K is located between the relay electrodes 33 adjacent to each other in the main scanning direction x, or between a pair of tips on the upstream side of the relay electrodes 33 in the sub-scanning direction y. The setting of the removal region 49K is set according to the manufacturing conditions for performing the removal process, and does not necessarily mean adding a recognizable mark to the resistor film 4K, forming a characteristic geometric shape, or arranging jigs or the like. As described above, the process of removing a part of the resistor film 40 is performed after the resistor paste is sintered and cured. This is also true in other embodiments.

In the present embodiment, the method of removing the removal region 49K of the resistor film 4K is not limited at all. As the removal method, a method using a laser, a cutting method using a cutting tool such as a rotary knife (cutting blade) containing sand grains, a wire saw, or the like, and the like are appropriately listed. In the present embodiment, as shown in fig. 18 and 19, a plurality of removal regions 49K are removed using a laser beam L. The type of laser light L is not limited as long as the removal region 49K can be removed. In the present embodiment, a so-called picosecond laser having a pulse width of, for example, about 1ps to about 25ps is used as the laser light L. Alternatively, a so-called nanosecond laser may be used. The wavelength of the laser light L is not limited, and for example, an infrared laser light having a wavelength in the infrared region is used.

In the present embodiment, the laser light L scans the removal region 49K along the sub-scanning direction y. That is, the laser light L scans the position on the upstream side in the sub-scanning direction y of the removed region 49K of the resistor layer 4 along the sub-scanning direction y from the position on the downstream side in the sub-scanning direction y of the removed region 49K of the resistor layer 4 through the removed region 49K of the resistor layer 4. Then, slits extending in the sub-scanning direction y are formed in the resistor film 4K, and the heat generating portions 41 are formed in this order. By removing all of the removed region 49K, the resistor layer 4 including the plurality of heat generating portions 41 shown in fig. 3 is formed. In fig. 3, the portion irradiated with the laser light L is shown by a phantom line. The trace of the portion irradiated with the laser light L may become a discolored portion or the like and may remain as a processing trace 109 for dividing adjacent heat generating portions 41. When the removal region 49K is removed by using a rotary knife or the like including sand grains, a machining mark 109 due to the sand grains remains on the surface formed by removing the resistor layer 4.

In the resistor film removal process of the present disclosure, the process of removing the removal region 49K is not limited to a structure in which the resistor film 4K is clearly divided and then the plurality of heat generation portions 41 are completely formed in the respective regions. For example, as a result of setting the output of the laser light L, the thickness of the resistor film 4K, and the like, the adjacent heat generating portions 41 can be connected to each other through the minute portion of the resistor layer 4. Even with such a configuration, if the heat generating portions 41 generate heat substantially individually and are configured to be capable of forming independent print dots, the structure formed by the resistor film removing process of the present disclosure is included. This also applies to the following embodiments.

[ protective layer Forming Process ]

Next, the protective layer 2 is formed. The protective layer 2 is formed by depositing SiN on the insulating layer 19, the wiring layer 3, and the resistor layer 4 by using, for example, a CVD method. In addition, the protective layer 2 is partially removed by etching or the like, thereby forming the pad opening 21. Then, one silicon wafer is divided into a plurality of substrates 10 by a dicing apparatus or the like (see fig. 1, 4, and 5).

Thereafter, an assembly process is performed on 1 substrate 10. The thermal head a1 is obtained by steps of mounting the base 10 and the connection substrate 5 on the heat dissipation member 8, mounting the driver IC7 on the connection substrate 5, bonding the plurality of wires 61 and the plurality of wires 62, and forming the protective resin 78.

In the present embodiment, the removal region 49K is set and the resistor layer 4 is removed also in the boundary between one 1 st heat generating portion 411 and one 2 nd heat generating portion 412 (for example, the fourth 1 st heat generating portion 411 from the left and the third 2 nd heat generating portion 412 from the left in fig. 3) which are adjacent to each other and constitute one printed dot. The removal region 49K may not be set at the boundary. This leaves the resistor layer 4 in the boundary. Therefore, a laterally long rectangular region in which a1 st heat generating portion 411 and a2 nd heat generating portion 412 adjacent to each other are connected constitutes one printed dot. When a laterally long rectangular region generates heat, the temperature of the central portion of the region sometimes rises. As long as the increased temperature does not affect the shape of one printed dot, a configuration may be adopted in which adjacent one 1 st heat generating portion 411 and one 2 nd heat generating portion 412 are connected. In this case, since the time for the process of removing the removal region 49K is reduced by half, the man-hours for manufacturing the thermal head a1 can be reduced.

Next, the operation of the method for manufacturing the thermal head a1 and the thermal head a1 will be described.

The entire wiring layer 3 of the thermal head a1 directly contacts the insulating layer 19 of the substrate 1. The wiring layer 3 is formed by a thin film forming method such as sputtering or CVD. On the other hand, the resistor layer 4 is a structure overlapping with a part of the wiring layer 3, and is not required to be formed by a thin film forming method such as sputtering or CVD. In the present embodiment, the resistor layer 4 is obtained by applying a resistor paste and firing the same. The resistor film is partially removed to form a plurality of heat generating portions 41. Therefore, first, the resistor layer 4 can be formed more easily than in the case where the resistor layer 4 interposed between the substrate 1 and the wiring layer 3 is formed on the entire substrate 1 by a thin film forming method. Second, the plurality of heat generating portions 41 can be formed more easily than in the case where the resistor body pattern is formed by applying the photolithography technique. Therefore, the thermal head a1 can be manufactured more easily.

As shown in fig. 3, the adjacent 1 st and 2 nd heat generating portions 411 and 412 constitute one printed dot. First, the dimension yd in the sub-scanning direction y of one printed dot is not determined by the width of the resistor to be printed (the dimension in the sub-scanning direction y), but is defined by the distance between the tip of the 2 nd band-shaped portion 345 and the tip of the relay electrode 33. The distance is determined by etching the conductive film 3K (see fig. 3 and 14). The current flows through the resistor region corresponding to the distance, and the resistor region generates heat. Therefore, since the distance is obtained with high accuracy by etching, the accuracy of the dimension yd can be improved as compared with a case where the dimension yd of one print dot is determined by the width of the resistor (see fig. 24).

Second, the dimension xd along the main scanning direction x of one printed dot is defined by the length obtained by subtracting the dimension (the width of one processing trace 109) along the main scanning direction x of one processing trace 109 from the dot pitch (the distance between the centers of adjacent dots). The length is determined by the laser light L or the width (dimension in the main scanning direction x) of one processing mark 109 of the cutting tool. Therefore, since the length is obtained with high accuracy, the accuracy of the size xd of one printed dot is improved. Further, since the resistor layer 4 is not present in the width portion of one processing trace 109, heat is hard to be transferred from the heating element corresponding to one point to both sides in the x direction. This makes it possible to obtain the thermal head a1 that can achieve good print quality by making the size and shape of the dots formed by the thermal head a1 uniform.

As shown in fig. 16, after the resistor film 4K in a band shape extending in the main scanning direction x is formed, as shown in fig. 18 and 19, the plurality of removed regions 49K of the resistor film 4K are removed, thereby forming a plurality of heat generating portions 41. This method can improve the manufacturing efficiency, for example, compared to the case where the resistor paste is applied to a plurality of small areas corresponding to the size, shape, and number of the plurality of heat generating portions 41.

In the resistor film removal process shown in fig. 18 and 19, the removal region 49K can be removed more accurately by using the laser light L. In addition, if the laser light L is used, the removal region 49K of various shapes can be removed. Further, if picosecond laser light having a pulse width of, for example, about 1ps to about 25ps is used as the laser light L, the heat generating portion 41 having a sharper outer shape can be formed.

In the thermal head a1, the plurality of heat generating portions 41 are arranged on the top 130 and the 1 st inclined portion 131B of the projection 13. Thus, even when the radius 910 (see fig. 4) passing through the contact position between the platen roller 91 and each heat generating portion 41 is shifted to the downstream side in the sub-scanning direction y with respect to the convex portion 13, good printing quality can be obtained. Such arrangement is advantageous in avoiding interference between the platen roller 91 and the protective resin 78 described later, and can reduce the sub-scanning direction y of the substrate 1.

Fig. 20 to 27 show another embodiment of the present disclosure. In the drawings, the same or similar elements as those of the above-described embodiment are denoted by the same reference numerals as those of the above-described embodiment.

< embodiment 1, modification 1 >

Fig. 20 shows a modification 1 of the thermal head a 1. The thermal head a11 of the present example is different from the thermal head a1 in the formation positions of the wiring layer 3 and the resistor layer 4.

In this example, the resistor layer 4 (the plurality of heat generating portions 41) is formed on the top 130 of the convex portion 13. The top ends of the 1 st band 342 and the 2 nd band 345 are located on the top 130. Further, the tip of the relay electrode 33 on the upstream side in the sub-scanning direction y is located on the top 130.

According to this modification as well, the thermal head a11 can be manufactured more easily. As is clear from this modification, the arrangement as viewed in the thickness direction z of the wiring layer 3 and the resistor layer 4 is not limited at all.

< embodiment 1, variation 2 >

Fig. 21 and 22 show a modification 2 of the thermal head a 1. The base material 10 of the thermal head a12 of the present modification example has an end face 15. The end surface 15 is a surface facing the downstream side in the sub-scanning direction y. In addition, the convex portion 13 contacts the end surface 15. That is, the main surface 11 is present only on the upstream side in the sub-scanning direction y with respect to the convex portion 13, and does not have a portion on the downstream side in the sub-scanning direction y with respect to the convex portion 13.

The relay electrode 33 is formed on the 1 st inclined portion 131B and the 2 nd inclined portion 132B. Relay electrode 33 has no portion exposed from projection 13.

According to this modification as well, the thermal head a12 can be manufactured more easily. Further, since the main surface 11 is located only on the upstream side in the sub-scanning direction y with respect to the convex portion 13, the thermal printer Pr can be set in a state where the radius 910 is further inclined than in the printing state shown in fig. 4. This is preferable for suppressing interference between the thermal printer Pr and the protective resin 78.

< embodiment 2 >

Fig. 23 shows a thermal print head according to a second embodiment of the present disclosure. The structure of the wiring layer 3 of the thermal head a2 of the present embodiment is different from the above-described embodiments.

The wiring layer 3 of the present embodiment includes a common electrode 31 and a plurality of individual electrodes 32. The common electrode 31 is connected to the plurality of heat generating portions 41 of the resistor layer 4 from the downstream side in the sub-scanning direction y. The individual electrodes 32 are connected to the heat generating portions 41 of the resistor layer 4 from the upstream side in the sub-scanning direction y.

The common electrode 31 of the present embodiment includes a connection portion 351 and a plurality of 3 rd band-shaped portions 352. The coupling portion 351 is disposed near an end edge on the downstream side of the substrate 1 in the sub-scanning direction y, and is in a belt shape extending in the main scanning direction x. The 3 rd band-shaped portions 352 extend from the coupling portion 351 toward the upstream side in the sub-scanning direction y, and are arranged at equal intervals in the main scanning direction x. The common electrode 31 is connected to a portion (not shown) of the wiring layer 3, which is electrically connected to a common line for supplying a printing voltage to the connector 59. This portion is located on the upstream side in the sub-scanning direction y than the convex portion 13. The specific configuration of the path for conducting the common electrode 31 to this site is not limited at all. A path that bypasses one side or both sides of the convex portion 13 in the main scanning direction x may be employed. Or a conductive layer provided between the substrate 10 and the insulating layer 19 is used as a conductive path.

The individual electrodes 32 each have a4 th stripe 355. The 4 th band-shaped portion 355 is a band-shaped portion extending in the sub-scanning direction y, and the common electrode 31 and the 3 rd band-shaped portion 352 are arranged to face each other on the upstream side in the sub-scanning direction y. A3 rd band portion 352 and a4 th band portion 355 are connected to a heat generating portion 41.

The method of manufacturing the thermal head a2 is the same as the method of manufacturing the thermal head a1 described above, for example. Therefore, the resistor layer 4 (heat generating portion 41) has a portion overlapping with the tip portions of the 3 rd band-shaped portion 352 and the 4 th band-shaped portion 355. Therefore, the dimension along the sub-scanning direction y of the heat generating portion 41 is larger than the distance between the tip of the 4 th belt-shaped portion 355 and the tip of the 3 rd belt-shaped portion 352.

In the present embodiment, the thermal head a2 can be manufactured more easily. In addition, one of the individual electrodes 32 is energized, and thus, only one of the heat generating portions 41 generates heat. Thus, one printing dot is constituted by one heat generating portion 41. This enables high definition of the thermal head a 2.

For example, embodiment 1 (see fig. 3) and this embodiment (see fig. 23) are compared. In fig. 3, a dot pitch between one printed dot composed of the 4 th 1 st heat generating portion 411 and the 3 rd 2 nd heat generating portion 412 from the left and one printed dot composed of the 5 st 1 st heat generating portion 411 and the 6 nd 2 nd heat generating portion 412 from the left is considered, respectively. When the dot pitch is 84.7 μm, the dot density corresponds to 300dpi (dots per inch). According to the present embodiment, one heat generating portion 41 shown in fig. 23 constitutes one printed dot. In the case where the wiring shown in fig. 3 and the wiring shown in fig. 23 have the same wiring pitch (center-to-center distance of adjacent wirings), as shown in fig. 23, the pitch between two adjacent heat generating portions 41 (center-to-center distance of adjacent heat generating portions 41) is 42.3(≈ 84.7/2) μm. In this case, the dot density corresponds to 600dpi (dots per inch).

< embodiment 3 >

Fig. 24 shows a thermal print head according to embodiment 3 of the present disclosure. The structure of the wiring layer 3 and the resistor layer 4 of the thermal head a3 of the present embodiment is different from the above-described embodiments.

The common electrode 31 includes a connection portion 361 and a 5 th band-shaped portion 362. The coupling portion 361 is disposed near an end edge of the substrate 1 on the downstream side in the sub-scanning direction y, and has a belt shape extending in the main scanning direction x. The 5 th belt-like portions 362 extend from the connection portion 361 to the upstream side in the sub-scanning direction y, and are arranged at equal intervals in the main scanning direction x. The 5 th belt-like portion 362 of the present embodiment reaches the 1 st inclined portion 131A from the downstream side in the sub-scanning direction y through the main surface 11, the 2 nd inclined portion 132B, the 1 st inclined portion 131B, and the ceiling portion 130. The tips of the 5 th band-shaped portions 362 on the upstream side in the sub-scanning direction y protrude from the resistor layer 4 when viewed in the thickness direction z.

Each of the individual electrodes 32 has a 6 th stripe portion 365. The 6 th strip portion 365 is a strip extending in the sub-scanning direction y and is disposed between the 5 th strip portions 362 adjacent to each other in the main scanning direction x. The 6 th belt-like portion 365 reaches the 2 nd inclined portion 132B from the upstream side in the sub scanning direction y through the main surface 11, the 2 nd inclined portion 132A, the 1 st inclined portion 131A, the ceiling portion 130, and the 1 st inclined portion 131B. The 6 th strip portions 365 protrude from the resistor layer 4 at the tip ends on the downstream side in the sub-scanning direction y when viewed in the thickness direction z.

The resistor layer 4 is a belt-like member extending in the main scanning direction x, and the entire member is formed of a single continuous region. The resistor layer 4 spans the 5 th band portions 362 and the 6 th band portions 365, and overlaps with a part of the 5 th band portions 362 and the 6 th band portions 365. The resistor layer 4 was manufactured by a manufacturing method in which the resistor film removing process in the resistor layer forming step in the manufacturing method of the thermal head a1 was omitted.

In the thermal head a3, when one of the individual electrodes 32 is electrically connected to the ground electrode, current flows from the connection portion 361 to the two 5 th band-shaped portions 362 adjacent to the one 6 th band-shaped portion 365, and the one 6 th band-shaped portion 365 is connected to the individual electrode 32. Therefore, in the resistor layer 4, the portion sandwiched between the one 6 th band-shaped portion 365 and the two 5 th band-shaped portions 362 adjacent thereto becomes the heat generating portion 41. The two heat generating portions 41 constitute one printing dot.

According to this embodiment, the thermal head a3 can be manufactured more easily. The resistive layer 4 of the present embodiment is formed of one continuous region, and does not have a plurality of small regions that are distinguished from each other. Therefore, it is not necessary to perform the resistor film removal process in the resistor layer forming step. This is preferable for improving manufacturing efficiency.

< embodiment 3, modification 1 >

Fig. 25 shows a thermal print head of embodiment 3 of the present disclosure. The thermal head a31 of the present modification differs from the above-described embodiment in the structure of the wiring layer 3 and the resistor layer 4. In the thermal head a31, in a portion where the wiring layer 3 and the resistor layer 4 overlap, the resistor layer 4 is interposed between the wiring layer 3 and the substrate 1 (insulating layer 19). That is, the resistor layer 4 is in direct contact with the substrate 1 (insulating layer 19). Such a modification can be suitably applied to the thermal heads a1 and a 2.

Fig. 26 is a flowchart showing an example of a method of manufacturing the thermal head a 31. As shown in the drawing, the manufacturing method of this example is performed in the order of the substrate preparation step, the resistor layer formation step, the wiring layer formation step, and the protective layer formation step. The processing and the like performed in each step are the same as those in the above-described method for manufacturing the thermal head a 1.

According to this modification as well, the thermal head a31 can be manufactured more easily. Further, according to the present modification, even in the structure in which the resistor layer 4 is interposed between the substrate 1 and the wiring layer 3, the effect of the method of coating and sintering the resistor layer 4 can be exhibited.

< embodiment 4 >

Fig. 27 shows a thermal head according to embodiment 4 of the present disclosure. The structure of the substrate 1 of the thermal head a4 of the present embodiment is different from the above-described embodiments.

In the substrate 1 of the present embodiment, the convex portion 13 is not formed on the base 10. That is, the substrate 10 has no portion protruding from the main surface 11. The wiring layer 3 and the resistor layer 4 are disposed on the main surface 11.

According to such an embodiment, the thermal head a4 can be manufactured more easily. In addition, according to the present embodiment, the base 10 of the substrate 1 is not limited to the structure having the convex portion 13.

The thermal print head and the method of manufacturing the thermal print head of the present disclosure are not limited to the above-described embodiments. The specific configuration of each part of the thermal print head and the method of manufacturing the thermal print head of the present disclosure can be variously modified in design.

[ additional notes 1]

A thermal print head is provided, characterized in that,

the thermal print head includes:

a substrate including a base material made of a single crystal semiconductor;

a resistor layer supported by the substrate and having a plurality of heat generating portions arranged in a main scanning direction; and

a wiring layer supported by the substrate and constituting a current-carrying path leading to the plurality of heat generating parts,

the wiring layer is in contact with the substrate,

the resistor layer has a portion overlapping the wiring layer from the opposite side of the substrate in the thickness direction.

[ appendix 2]

The thermal head according to supplementary note 1, wherein,

the substrate includes an insulating layer interposed between the base material and the wiring layer.

[ additional notes 3]

The thermal head according to supplementary note 2, wherein,

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

the plurality of heat generating portions overlap the convex portion as viewed in the thickness direction.

[ additional notes 4]

The thermal head according to supplementary note 3, wherein,

the convex portion includes: a top portion having a largest distance from the main surface, an upstream-side 1 st inclined portion connected to the top portion from an upstream side in a sub-scanning direction, and a downstream-side 1 st inclined portion connected to the top portion from a downstream side in the sub-scanning direction,

the heat generating portion overlaps the top portion as viewed in the thickness direction.

[ additional notes 5]

The thermal head according to supplementary note 4, wherein,

the convex portion further includes: an upstream side 2 nd inclined portion connected to an opposite side of the apex portion in a sub-scanning direction with respect to the upstream side 1 st inclined portion; a downstream side 2 nd inclined portion connected to an opposite side of the apex portion in a sub-scanning direction with respect to the downstream side 1 st inclined portion.

[ additional notes 6]

The thermal print head according to any one of supplementary notes 1 to 5,

the plurality of heat generating portions include: a pair of 1 st heat generating portions arranged apart from each other in the main scanning direction and adjacent to each other in the main scanning direction; a pair of 2 nd heat generating parts disposed on both sides in the main scanning direction with the pair of 1 st heat generating parts interposed therebetween,

the wiring layer has:

a common electrode; the common electrode includes: a pair of 1 st belt-shaped parts extending in the sub-scanning direction and arranged separately in the main scanning direction, and a base part connected to the pair of 1 st belt-shaped parts from the upstream side in the sub-scanning direction,

individual electrodes; has 2 nd belt-shaped parts arranged separately on both sides in the main scanning direction with the pair of 1 st belt-shaped parts interposed therebetween,

and a pair of relay electrodes,

the pair of 1 st belt-shaped parts are separately connected with the pair of 1 st heat generating parts from the upstream side in the sub-scanning direction,

the 2 nd band-shaped portion of the pair of individual electrodes is connected to the pair of 2 nd heat generating portions from the upstream side in the sub-scanning direction in the main scanning direction,

the relay electrode is connected to the 1 st and 2 nd heat generating portions adjacent to each other in the main scanning direction from a downstream side in the sub-scanning direction.

[ additional notes 7]

The thermal head according to supplementary note 6, wherein,

the dimension of the 1 st heat generating portion and the 2 nd heat generating portion in the sub-scanning direction is larger than the distance between the 1 st strip portion or the 2 nd strip portion and the relay electrode in the sub-scanning direction.

[ additional notes 8]

The thermal head according to supplementary note 6 or 7, wherein,

the dimension of the 1 st heat generating portion and the 2 nd heat generating portion in the main scanning direction is larger than the dimension of each of the 1 st belt-shaped portion and the 2 nd belt-shaped portion in the main scanning direction.

[ appendix 9]

The thermal print head according to any one of supplementary notes 6 to 8,

the substrate is formed with processing traces that divide the heat generating portions adjacent in the main scanning direction.

[ appendix 10]

The thermal print head according to any one of supplementary notes 1 to 5,

the wiring layer includes: a common electrode connected to the plurality of heat generating portions of the resistor layer from a downstream side in a sub-scanning direction; and individual electrodes individually connected to the plurality of heat generating portions of the resistor layer from an upstream side in a sub-scanning direction.

[ appendix 11]

The thermal print head according to supplementary note 10, wherein,

the plurality of heat generating portions are arranged apart from each other in the main scanning direction,

the common electrode has: a coupling portion extending in the main scanning direction; a plurality of 3 rd strip-shaped parts which respectively extend from the connecting part at the upstream side in the sub scanning direction and are arranged along the main scanning direction,

the plurality of individual electrodes have: a plurality of 4 th belt-shaped parts extending in the sub-scanning direction and arranged opposite to each other at the upstream side in the sub-scanning direction relative to the plurality of 3 rd belt-shaped parts,

the plurality of 3 rd band parts and the plurality of 4 th band parts are individually connected to the plurality of heat generating parts.

[ appendix 12]

The thermal head according to supplementary note 11, wherein,

the dimension of the heat generating portion in the sub-scanning direction is larger than the distance between the 3 rd band-shaped portion and the 4 th band-shaped portion in the sub-scanning direction.

[ additional notes 13]

The thermal head according to supplementary note 11 or 12, wherein,

the dimension of the heat generating portion in the main scanning direction is larger than the dimensions of the 3 rd and 4 th belt-shaped portions in the main scanning directions.

[ appendix 14]

The thermal print head according to any one of supplementary notes 11 to 13,

the substrate is formed with processing traces that divide the heat generating portions adjacent in the main scanning direction.

[ appendix 15]

The thermal print head according to supplementary note 10, wherein,

the common electrode has: a connecting portion extending in the main scanning direction, and a plurality of 5 th belt-shaped portions extending from the connecting portion on the upstream side in the sub-scanning direction and arranged apart from each other in the main scanning direction,

the plurality of individual electrodes have: a 6 th strip portion extending in the sub-scanning direction and located between the 5 th strip portions adjacent in the main scanning direction,

the resistor layer has a strip shape overlapping with the 5 th strip portion and the 6 th strip portion and extending in the main scanning direction,

the portion of the resistor layer sandwiched between the adjacent 5 th band-shaped portions constitutes the heat generating portion.

[ additional notes 16]

The thermal print head according to supplementary note 15, wherein,

the 5 th band-shaped portion extends from the resistor layer toward the upstream side in the sub-scanning direction,

the 6 th band-shaped portion extends from the resistor layer toward the downstream side in the sub-scanning direction.

[ additional character 17]

A method of manufacturing a thermal print head,

the manufacturing method comprises the following steps:

a process for preparing a substrate including a base material made of a single crystal semiconductor;

a process of forming a wiring layer supported on the substrate; and

a process of forming the resistor layer is described,

the process of forming the wiring layer includes: a conductive film forming process using sputtering or CVD method,

the process of forming the resistor layer includes: a process of applying a resistor paste and a process of firing the resistor paste.

[ additional notes 18]

The method of manufacturing a thermal head according to supplementary note 17,

the process of forming the resistor layer is performed after the process of forming the wiring layer.

[ appendix 19]

The method of manufacturing a thermal head according to supplementary note 17,

the process of forming the resistor layer is performed before the step of forming the wiring layer.

[ appendix 20]

The method of manufacturing a thermal head according to any one of supplementary notes 17 to 19, wherein,

the process of forming the resistor layer further includes: and a process of forming a plurality of heat generating portions arranged apart from each other in the main scanning direction by partially removing the resistor layer after the process of firing the resistor paste.

Description of the symbols

A1, a11, a12, a2, A3, a31, a 4: thermal print head

1: substrate

1K: substrate material

2: protective layer

3: wiring layer

3K: conductive film

4: resistor layer

4K: resistor film

5: connection substrate

7: driver IC

8: heat dissipation component

10: base material

11. 11K: major face

12. 12K: back side of the panel

13. 13K: convex part

15: end face

19: insulating layer

21: gasket opening

31: common electrode

32: individual electrode

33: relay electrode

40: resistor film

41: heating part

49K: removing the region

51: major face

52: back side of the panel

59: connectors 61, 62: thread

78: protective resin

81: 1 st bearing surface

82: 2 nd bearing surface

91: paper pressing roller

109: machining trace

130. 130K: top part

131A, 131B: 1 st inclined part

132A, 132B: 2 nd inclined part

132K: inclined part

321: single pad

341: base part

342: 1 st band part

345: 2 nd band part

351: connecting part

352: 3 rd belt part

355: 4 th belt part

361: connecting part

362: 5 th band part

365: 6 th belt part

411: no. 1 heat generating part

412: no. 2 heat generating part

910: radius of

L: laser

Pr: thermal printer

x: main scanning direction

y: sub scanning direction

z: thickness direction

α 1: angle of inclination 1

α 2: the 2 nd inclination angle.

Claims (20)

1. A thermal print head is provided, characterized in that,

the thermal print head includes:

a substrate including a base material made of a single crystal semiconductor;

a resistor layer supported by the substrate and having a plurality of heat generating portions arranged in a main scanning direction; and

a wiring layer supported by the substrate and constituting a current-carrying path leading to the plurality of heat generating parts,

the wiring layer is in contact with the substrate,

the resistor layer has a portion overlapping the wiring layer from the opposite side of the substrate in the thickness direction.

2. The thermal print head of claim 1,

the substrate includes an insulating layer interposed between the base material and the wiring layer.

3. The thermal print head of claim 2,

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

the plurality of heat generating portions overlap the convex portion as viewed in the thickness direction.

4. A thermal print head according to claim 3,

the convex portion includes: a top portion having a largest distance from the main surface, an upstream-side 1 st inclined portion connected to the top portion from an upstream side in a sub-scanning direction, and a downstream-side 1 st inclined portion connected to the top portion from a downstream side in the sub-scanning direction,

the heat generating portion overlaps the top portion as viewed in the thickness direction.

5. A thermal print head according to claim 4,

the convex portion further includes: an upstream side 2 nd inclined portion connected to an opposite side of the apex portion in a sub-scanning direction with respect to the upstream side 1 st inclined portion; a downstream side 2 nd inclined portion connected to an opposite side of the apex portion in a sub-scanning direction with respect to the downstream side 1 st inclined portion.

6. A thermal print head according to any one of claims 1 to 5,

the plurality of heat generating portions include: a pair of 1 st heat generating portions arranged apart from each other in the main scanning direction and adjacent to each other in the main scanning direction; a pair of 2 nd heat generating parts disposed on both sides in the main scanning direction with the pair of 1 st heat generating parts interposed therebetween,

the wiring layer has:

a common electrode; the common electrode includes: a pair of 1 st belt-shaped parts extending in the sub-scanning direction and arranged separately in the main scanning direction, and a base part connected to the pair of 1 st belt-shaped parts from the upstream side in the sub-scanning direction,

individual electrodes; has 2 nd belt-like parts disposed separately on both sides in the main scanning direction with the pair of 1 st belt-like parts interposed therebetween, an

A pair of relay electrodes, which are arranged in parallel,

the pair of 1 st belt-shaped parts are separately connected with the pair of 1 st heat generating parts from the upstream side in the sub-scanning direction,

the 2 nd band-shaped portion of the pair of individual electrodes is connected to the pair of 2 nd heat generating portions from the upstream side in the sub-scanning direction in the main scanning direction,

the relay electrode is connected to the 1 st and 2 nd heat generating portions adjacent to each other in the main scanning direction from a downstream side in the sub-scanning direction.

7. A thermal print head according to claim 6,

the dimension of the 1 st heat generating portion and the 2 nd heat generating portion in the sub-scanning direction is larger than the distance between the 1 st strip portion or the 2 nd strip portion and the relay electrode in the sub-scanning direction.

8. The thermal print head of claim 6 or 7,

the dimension of the 1 st heat generating portion and the 2 nd heat generating portion in the main scanning direction is larger than the dimension of each of the 1 st belt-shaped portion and the 2 nd belt-shaped portion in the main scanning direction.

9. A thermal print head according to any one of claims 6 to 8,

the substrate is formed with processing traces that divide the heat generating portions adjacent in the main scanning direction.

10. A thermal print head according to any one of claims 1 to 5,

the wiring layer includes: a common electrode connected to the plurality of heat generating portions of the resistor layer from a downstream side in a sub-scanning direction; and individual electrodes individually connected to the plurality of heat generating portions of the resistor layer from an upstream side in a sub-scanning direction.

11. The thermal print head of claim 10,

the plurality of heat generating portions are arranged apart from each other in the main scanning direction,

the common electrode has: a coupling portion extending in the main scanning direction; a plurality of 3 rd strip-shaped parts which respectively extend from the connecting part at the upstream side in the sub scanning direction and are arranged along the main scanning direction,

the plurality of individual electrodes have: a plurality of 4 th belt-shaped parts extending in the sub-scanning direction and arranged opposite to each other at the upstream side in the sub-scanning direction relative to the plurality of 3 rd belt-shaped parts,

the plurality of 3 rd band parts and the plurality of 4 th band parts are individually connected to the plurality of heat generating parts.

12. The thermal print head of claim 11,

the dimension of the heat generating portion in the sub-scanning direction is larger than the distance between the 3 rd band-shaped portion and the 4 th band-shaped portion in the sub-scanning direction.

13. The thermal print head of claim 11 or 12,

the dimension of the heat generating portion in the main scanning direction is larger than the dimensions of the 3 rd and 4 th belt-shaped portions in the main scanning directions.

14. The thermal print head according to any one of claims 11 to 13,

the substrate is formed with processing traces that divide the heat generating portions adjacent in the main scanning direction.

15. The thermal print head of claim 10,

the common electrode has: a connecting portion extending in the main scanning direction, and a plurality of 5 th belt-shaped portions extending from the connecting portion on the upstream side in the sub-scanning direction and arranged apart from each other in the main scanning direction,

the plurality of individual electrodes have: a 6 th strip portion extending in the sub-scanning direction and located between the 5 th strip portions adjacent in the main scanning direction,

the resistor layer has a strip shape overlapping with the 5 th strip portion and the 6 th strip portion and extending in the main scanning direction,

the portion of the resistor layer sandwiched between the adjacent 5 th band-shaped portions constitutes the heat generating portion.

16. The thermal print head of claim 15,

the 5 th band-shaped portion extends from the resistor layer toward the upstream side in the sub-scanning direction,

the 6 th band-shaped portion extends from the resistor layer toward the downstream side in the sub-scanning direction.

17. A method of manufacturing a thermal print head,

the manufacturing method comprises the following steps:

a process for preparing a substrate including a base material made of a single crystal semiconductor;

a process of forming a wiring layer supported on the substrate; and

a process of forming the resistor layer is described,

the process of forming the wiring layer includes: a conductive film forming process using sputtering or CVD method,

the process of forming the resistor layer includes: a process of applying a resistor paste and a process of firing the resistor paste.

18. The method of manufacturing a thermal print head according to claim 17,

the process of forming the resistor layer is performed after the process of forming the wiring layer.

19. The method of manufacturing a thermal print head according to claim 17,

the process of forming the resistor layer is performed before the step of forming the wiring layer.

20. The method of manufacturing a thermal print head according to any one of claims 17 to 19,

the process of forming the resistor layer further includes: and a process of forming a plurality of heat generating portions arranged apart from each other in the main scanning direction by partially removing the resistor layer after the process of firing the resistor paste.

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