JP7022239B2 - Thermal print head - Google Patents

Description

The present invention relates to a thermal print head.

Conventionally known thermal printheads include a substrate, a resistor layer, and a wiring layer. Such a thermal print head is disclosed in, for example, Patent Document 1. In the thermal printhead disclosed in the same document, the resistor layer and the wiring layer are formed on the substrate. The resistor layer has a plurality of heat generating portions arranged in the main scanning direction.

In order to perform printing more reliably, it is preferable to press the plurality of heat generating portions against the printing medium more strongly. However, it should be avoided that the print medium interferes with a portion of the thermal print head other than the plurality of heat generating portions.

Japanese Unexamined Patent Publication No. 2012-51319

The present invention has been conceived under the above circumstances, and an object of the present invention is to provide a thermal print head capable of printing more reliably.

The thermal printhead provided by the present invention is supported by the semiconductor substrate, a resistor layer supported by the semiconductor substrate and having a plurality of heat generating portions arranged in the main scanning direction to generate heat by energization, and the semiconductor substrate. A thermal print head including a wiring layer included in a conduction path for energizing the plurality of heat generating portions, wherein the semiconductor substrate has a main surface and a back surface facing opposite sides in the thickness direction, and the above-mentioned It has a convex portion that protrudes from the main surface in the thickness direction and extends long in the main scanning direction, and the plurality of heat generating portions are characterized in that they overlap with the convex portion in the thickness direction view.

In a preferred embodiment of the present invention, the main surface has a first region and a first region that are separated from each other in the sub-scanning direction with the convex portion interposed therebetween.

In a preferred embodiment of the present invention, the convex portion is interposed at a top surface parallel to the main surface and separated from the main surface in the thickness direction, between the top surface and the first region. It also has a first inclined side surface that is inclined with respect to the main surface, and a first inclined side surface that is interposed between the top surface and the first region and is inclined with respect to the main surface.

In a preferred embodiment of the present invention, the plurality of heat generating portions overlap with the top surface in the thickness direction.

In a preferred embodiment of the present invention, the convex portion is interposed between the top surface and the first inclined side surface, and the angle formed by the top surface is the angle formed by the first inclined side surface and the top surface. Has a first auxiliary tilted side that is smaller than.

In a preferred embodiment of the present invention, the convex portion is interposed between the top surface and the first inclined side surface, and the angle formed by the top surface is the angle formed by the first inclined side surface and the top surface. Has a first auxiliary tilted side that is smaller than.

In a preferred embodiment of the invention, the conduction path includes the semiconductor substrate.

In a preferred embodiment of the present invention, the wiring layer is arranged on a side opposite to the plurality of individual electrodes having the plurality of individual electrodes connected to the plurality of heat generating portions and the plurality of individual electrodes sandwiching the plurality of heat generating portions. It also has a common electrode that conducts with the plurality of heat generating portions, and the common electrode and the semiconductor substrate are conductive.

In a preferred embodiment of the present invention, an insulating protective layer covering the wiring layer and the resistor layer is provided.

In a preferred embodiment of the present invention, an insulating layer provided between the semiconductor substrate and the wiring layer and the resistor layer is provided, and the insulating layer conducts the semiconductor substrate and the common electrode. It has a first opening for a common electrode to be made to.

In a preferred embodiment of the present invention, the common electrode opening has a shape extending long in the main scanning direction.

In a preferred embodiment of the present invention, the resistor layer has a resistance-side through conduction portion that contacts the semiconductor substrate through the common electrode opening.

In a preferred embodiment of the present invention, the common electrode has a wiring-side through-conducting portion in contact with the resistance-side through-conducting portion.

In a preferred embodiment of the present invention, the insulating layer is located on the side opposite to the common electrode first opening in the sub-scanning direction with the plurality of heat generating portions interposed therebetween, and conducts the semiconductor substrate and the individual electrodes. It has a first opening for a common electrode to be made to.

In a preferred embodiment of the present invention, the resistor layer has a resistance-side through conduction portion that contacts the semiconductor substrate through the common electrode opening.

In a preferred embodiment of the present invention, the common electrode has a wiring-side through-conducting portion in contact with the resistance-side through-conducting portion.

In a preferred embodiment of the present invention, a plurality of control elements that conduct the wiring layer and individually energize the plurality of heat generating portions are provided.

In a preferred embodiment of the present invention, the common electrode opening overlaps with the control element in the thickness direction.

In a preferred embodiment of the invention, the insulating protective layer has a control element opening that exposes at least a portion of each of the plurality of individual electrodes and the common electrode.

In a preferred embodiment of the present invention, a control element pad formed in the control element opening is provided.

In a preferred embodiment of the present invention, the control element is conduction-bonded to the control element pad.

In a preferred embodiment of the present invention, the insulating protective layer is located on the side opposite to the plurality of heat generating portions with respect to the control element in the sub-scanning direction, and is an opening for a wiring member that exposes the wiring layer. Has.

In a preferred embodiment of the present invention, a wiring member pad formed in the wiring member opening is provided.

In a preferred embodiment of the present invention, the wiring member is joined to the wiring member pad.

In a preferred embodiment of the present invention, the wiring member is a flexible wiring board.

In a preferred embodiment of the present invention, the common electrode opening overlaps with the first region in the thickness direction.

In a preferred embodiment of the present invention, the common electrode opening overlaps with the first region in the thickness direction.

In a preferred embodiment of the invention, the control element overlaps the first region in the thickness direction.

In a preferred embodiment of the present invention, a conductive protective layer that overlaps with the plurality of heat generating portions and is laminated on the insulating protective layer in the thickness direction is provided.

In a preferred embodiment of the present invention, the conductive protective layer is made of TiN.

In a preferred embodiment of the present invention, the insulating protective layer has an opening for a conductive protective layer that conducts the conductive protective layer and the common electrode.

In a preferred embodiment of the present invention, the conductive protective layer has a protective layer penetrating conductive portion that contacts the common electrode through the opening for the conductive protective layer.

In a preferred embodiment of the present invention, the conductive protective layer opening overlaps with the first region in the thickness direction.

In a preferred embodiment of the present invention, the semiconductor substrate is made of a material in which Si is doped with a metal element.

In a preferred embodiment of the invention, the resistor layer is made of TaN.

In a preferred embodiment of the present invention, the wiring layer is made of Cu.

Other features and advantages of the invention will be more apparent by the detailed description given below with reference to the accompanying drawings.

It is a top view which shows the thermal print head based on 1st Embodiment of this invention. It is sectional drawing which follows the II-II line of FIG. FIG. 3 is an enlarged cross-sectional view of a main part showing the thermal print head of FIG. It is an enlarged plan view of the main part which shows the thermal print head of FIG. It is an enlarged sectional view of the main part which shows an example of the manufacturing method of the thermal print head of FIG. It is an enlarged sectional view of the main part which shows an example of the manufacturing method of the thermal print head of FIG. It is an enlarged sectional view of the main part which shows an example of the manufacturing method of the thermal print head of FIG. It is an enlarged sectional view of the main part which shows an example of the manufacturing method of the thermal print head of FIG. It is an enlarged sectional view of the main part which shows an example of the manufacturing method of the thermal print head of FIG. It is an enlarged sectional view of the main part which shows an example of the manufacturing method of the thermal print head of FIG. It is an enlarged sectional view of the main part which shows an example of the manufacturing method of the thermal print head of FIG. FIG. 3 is an enlarged cross-sectional view of a main part showing a modified example of the thermal print head of FIG. It is an enlarged sectional view of the main part which shows the thermal print head based on 2nd Embodiment of this invention. FIG. 3 is an enlarged cross-sectional view of a main part showing an example of a method for manufacturing the thermal print head of FIG.

Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

1 to 4 show a thermal print head based on the first embodiment of the present invention. The thermal print head A1 of the present embodiment includes a semiconductor substrate 1, an insulating layer 2, a wiring layer 3, a resistor layer 4, an insulating protective layer 5, a conductive protective layer 6, a plurality of control elements 7, a protective resin 8, and a support. It includes a member 91 and a wiring member 92. The thermal print head A1 is incorporated in a printer that prints on a print medium 992 that is sandwiched and conveyed between the platen roller 991 and the platen roller 991. Examples of such a print medium 992 include a bar code sheet and a thermal paper for producing a receipt.

FIG. 1 is a plan view showing the thermal print head A1. FIG. 2 is a cross-sectional view taken along the line II-II of FIG. FIG. 3 is an enlarged cross-sectional view of a main part showing the thermal print head A1. FIG. 4 is an enlarged plan view of a main part showing the thermal print head A1. For convenience of understanding, the support member 91 is omitted in FIG. Further, FIG. 4 shows a part of the thermal print head A1.

The semiconductor substrate 1 is made of a semiconductor material having a resistivity that allows energization. Examples of such a semiconductor material include a material in which Si is doped with a metal element. The semiconductor substrate 1 has a main surface 11, a back surface 12, and a convex portion 13.

The main surface 11 and the back surface 12 face each other in the thickness direction z. The convex portion 13 is a portion protruding from the main surface 11 in the thickness direction z. The convex portion 13 extends long in the main scanning direction x.

The main surface 11 has a first region 111 and a second region 112 that are separated from each other in the sub-scanning direction with the convex portion 13 interposed therebetween.

The convex portion 13 has a top surface 130, a first inclined side surface 131, and a second inclined side surface 132. The top surface 130 is parallel to the main surface 11 and is separated from the main surface 11 in the thickness direction. The first inclined side surface 131 is interposed between the top surface 130 and the first region 111, and is inclined with respect to the main surface 11. The second inclined side surface 132 is interposed between the top surface 130 and the second region 112, and is inclined with respect to the main surface 11.

In this embodiment, the (100) plane is selected as the main plane 11. Further, the angles formed by the first inclined side surface 131 and the second inclined side surface 132 with the top surface 130 and the main surface 11 are the same, for example, 54.7 degrees.

The main surface 11 has a first region 111 and a second region 112. The first region 111 and the second region 112 are regions partitioned from each other by the convex portion 13. In the present embodiment, the second region 112 has a larger sub-scanning direction y dimension and area than the first region 111.

The size of the semiconductor substrate 1 is not particularly limited, but for example, the sub-scanning direction y dimension of the semiconductor substrate 1 is about 2.0 mm to 3.0 mm, and the x-direction dimension is about 100 mm to 150 mm. The z-distance in the thickness direction between the main surface 11 and the back surface 12 is about 400 μm to 500 μm, and the z-height in the thickness direction of the convex portion 13 is about 250 μm to 400 μm.

The insulating layer 2 is provided between the main surface 11 and the convex portion 13 of the semiconductor substrate 1 and the wiring layer 3 and the resistor layer 4. The insulating layer 2 is made of an insulating material, for example, SiO ₂ or SiN. The thickness of the insulating layer 2 is not particularly limited, and an example thereof is, for example, about 5 μm to 10 μm.

The insulating layer 2 has a first opening 21 for a common electrode and a second opening 22 for a common electrode. The first opening 21 for the common electrode penetrates the insulating layer 2 in the thickness direction z. In the present embodiment, the first opening 21 for the common electrode overlaps with the first region 111 in the z-view in the thickness direction. Further, the first opening 21 for the common electrode has a shape extending long in the main scanning direction x, for example, a slit shape.

The second opening 22 for the common electrode penetrates the insulating layer 2 in the thickness direction z. In the present embodiment, the second opening 22 for the common electrode overlaps with the second region 112 in the z-view in the thickness direction.

The resistor layer 4 is supported by the semiconductor substrate 1 and is formed on the insulating layer 2 in the present embodiment. The resistor layer 4 has a plurality of heat generating portions 41. The plurality of heat generating units 41 locally heat the print medium 992 by selectively energizing each of them. The plurality of heat generating portions 41 are arranged along the main scanning direction x. In the present embodiment, the plurality of heat generating portions 41 overlap the convex portions 13 in the thickness direction z-view, and more specifically, all of them overlap the top surface 130. The resistor layer 4 is made of, for example, TaN.

The shape of the heat generating portion 41 is not particularly limited, but in the example shown in FIG. 4, the heat generating portion 41 has a bent shape.

In the present embodiment, the resistor layer 4 has a resistance-side first through conduction portion 421 and a resistance-side second through conduction portion 422. The resistance-side first through conduction portion 421 is in contact with the first region 111 of the main surface 11 of the semiconductor substrate 1 through the first opening 21 for the common electrode. The second through conduction portion 422 on the resistance side is in contact with the second region 112 of the main surface 11 of the semiconductor substrate 1 through the second opening 22 for the common electrode.

The wiring layer 3 is for forming a conduction path for energizing a plurality of heat generating portions 41. The wiring layer 3 is supported by the semiconductor substrate 1, and in the present embodiment, the wiring layer 3 is laminated on the resistor layer 4. The wiring layer 3 may be interposed between the semiconductor substrate 1 and the resistor layer 4. The wiring layer 3 is made of a metal material having a lower resistance than that of the resistor layer 4, and is made of, for example, Cu. Further, the wiring layer 3 may have a configuration having a layer made of Cu and a layer made of Ti interposed between the layer and the resistor layer 4.

The wiring layer 3 has a plurality of individual electrodes 31 and a common electrode 32. The plurality of individual electrodes 31 are individually connected to the plurality of heat generating portions 41. In the present embodiment, the plurality of individual electrodes 31 are located on the second region 112 side in the sub-scanning direction y with respect to the plurality of heat generating portions 41.

The common electrode 32 has a portion arranged on the side opposite to the plurality of individual electrodes 31 in the sub-scanning direction y with the plurality of heat generating portions 41 interposed therebetween. Further, the common electrode 32 of the embodiment has a portion located on the second region 112 side (left side in the figure in FIG. 3) in the sub-scanning direction y direction with respect to the plurality of individual electrodes 31. The common electrode 32 is electrically connected to all of the plurality of heat generating portions 41. Note that FIG. 3 shows a cross section crossing the common electrode 32 in the second region 112 for convenience of understanding, but in the cross section at another position in the main scanning direction x, the wiring layer 3 has a potential different from that of the common electrode 32. Has different and insulated parts.

As can be understood from FIGS. 3 and 4, in the present embodiment, the portion of the resistor layer 4 exposed from the wiring layer 3 between the plurality of individual electrodes 31 and the common electrode 32 is a plurality of heat generating portions. It is 41.

In the present embodiment, the common electrode 32 has a wiring-side first through conduction portion 321 and a wiring-side second through conduction portion 322. The wiring-side first through conductive portion 321 is in contact with the resistance-side first through conductive portion 421 of the resistor layer 4. The wiring side second through conduction portion 322 is in contact with the resistance side second through conduction portion 422 of the resistor layer 4. With such a configuration, the portion of the common electrode 32 of the wiring layer 3 that overlaps with the first region 111 in the thickness direction z is the first through conduction portion on the resistance side through the first opening 21 for the common electrode of the insulating layer 2. It is electrically connected to the semiconductor substrate 1 via 421. Further, the portion of the common electrode 32 that overlaps with the second region 112 in the z-view in the thickness direction passes through the second opening 22 for the common electrode of the insulating layer 2 and via the second through conduction portion 422 on the resistance side, thereby forming a semiconductor substrate. It is conducting with 1. As a result, in the present embodiment, the conduction path for energizing the plurality of heat generating portions 41 includes the wiring layer 3 and the semiconductor substrate 1. More specifically, the current flowing through the common electrode 32 is configured to pass through the semiconductor substrate 1.

The insulating protective layer 5 covers the wiring layer 3 and the resistor layer 4. The insulating protective layer 5 is made of an insulating material and protects the wiring layer 3 and the resistor layer 4. The material of the insulating protective layer 5 is, for example, SiO ₂ .

The insulating protective layer 5 has an opening 51 for a conductive protective layer, a plurality of openings 52 for control elements, and a plurality of openings 53 for wiring members. The opening 51 for the conductive protective layer overlaps with the first region 111 in the z-view in the thickness direction, and exposes the common electrode 32. The opening 51 for the conductive protective layer has a shape that extends long in, for example, the main scanning direction x. In the illustrated example, the opening 51 for the conductive protective layer overlaps with the first opening 21 for the common electrode in the z-view in the thickness direction. The opening 52 for the control element overlaps with the second region 112 in the z-view in the thickness direction, and exposes the plurality of individual electrodes 31 and the common electrode 32, respectively.

The plurality of wiring member openings 53 are provided on the side opposite to the plurality of heat generating portions 41 in the sub-scanning direction y with respect to the plurality of control element openings 52. The plurality of wiring member openings 53 expose the common electrode 32 of the wiring layer 3 and other parts of the wiring layer 3 provided at positions different from the common electrode 32 in the x direction and insulated from the common electrode 32, respectively. I'm letting you.

The conductive protective layer 6 overlaps with a plurality of heat generating portions 41 and is laminated on the insulating protective layer 5 in the z-viewing in the thickness direction. The conductive protective layer 6 is made of a conductive material, for example, AlN. The conductive protective layer 6 has a portion that overlaps with the first region 111 in the z-viewing in the thickness direction, and has a protective layer penetrating conductive portion 61. The conductive portion 61 penetrating the protective layer is in contact with the common electrode 32 through the opening 51 for the conductive protective layer.

The plurality of control elements 7 are for conducting the wiring layer 3 and individually energizing the plurality of heat generating portions 41. The plurality of control elements 7 are arranged in the main scanning direction x. The plurality of control elements 7 overlap with the second opening 22 for the common electrode in the z-viewing in the thickness direction.

In the present embodiment, the thermal print head A1 has a pad 381 for a control element. The control element pad 381 is made of a metal such as Cu or Ni, and is formed in the control element opening 52. The control element 7 has a plurality of control element electrodes 71. The control element electrode 71 is conductively bonded to the control element pad 381 via a conductive bonding material 79. The conductive bonding material 79 is, for example, solder.

In the present embodiment, the control element 7 is located on the semiconductor substrate 1 side in the thickness direction z with respect to the surface S6 of the conductive protective layer 6 above the thickness direction z of the conductive protective layer 6. Further, the control element 7 is located on the semiconductor substrate 1 side in the thickness direction z with respect to the resistor layer surface S4 which is the surface of the resistor layer 4 above the thickness direction z.

The wiring member 92 is for conducting the wiring layer 3 and, for example, a power supply unit (not shown) of a printer. The wiring member 92 is, for example, a printed wiring board. Such a wiring member 92 has, for example, a resin layer 921, a wiring layer 922, and a protective layer 923. The resin layer 921 is made of a flexible resin. The wiring layer 922 is laminated on the resin layer 921, and is made of a metal such as Cu. The protective layer 923 is laminated on the side opposite to the wiring layer 922 with respect to the resin layer 921, and is a layer that protects the resin layer 921 and the wiring layer 922.

The thermal print head A1 has a pad 382 for a wiring member. The wiring member pad 382 is formed in the wiring member opening 53 of the insulating protective layer 5, and is made of a metal such as Cu or Ni. The wiring layer 922 of the wiring member 92 is conduction-bonded to the wiring member pad 382. The thermal print head A1 has a plurality of wiring member pads 382. The wiring member pad 382 shown in FIG. 3 is conductive with the common electrode 32. Some of the plurality of wiring member pads 382 are conducting to other portions of the wiring layer 3 that are insulated from the common electrode 32 and are provided at positions different from those shown in FIG.

The support member 91 supports the semiconductor substrate 1. The support member 91 is made of a metal such as Al. The support member 91 has a recess 911. The recess 911 is a portion for accommodating the semiconductor substrate 1 and supports the semiconductor substrate 1. The semiconductor substrate 1 is bonded to the recess 911 by, for example, a bonding layer 919. The bonding layer 919 is preferably one that can transfer heat from the semiconductor substrate 1 to the support member 91 and can insulate the semiconductor substrate 1 and the support member 91. Examples of such a bonding layer 919 include a resin-based adhesive.

The dimensions of the support member 91 are not particularly limited, and for example, the sub-scanning direction y dimension is about 5.0 mm to 8.0 mm, and the x-direction dimension is about 100 mm to 150 mm. Further, the z dimension in the thickness direction is about 2.0 to 4.0 mm.

The protective resin 8 protects the control element 7, and is made of, for example, an insulating resin. Further, the protective resin 8 overlaps with the second inclined side surface 132 of the convex portion 13 in the z-viewing in the thickness direction, and exposes the top surface 130. In the present embodiment, the protective resin 8 covers a part of the wiring member 92.

Next, an example of a method for manufacturing the thermal print head A1 will be described below with reference to FIGS. 5 to 11.

First, a semiconductor substrate material is prepared. The semiconductor substrate material is made of a low resistance semiconductor material, for example, a material in which Si is doped with a metal element. Further, this semiconductor substrate material has a (100) plane. After covering the (100) surface with a predetermined mask layer, anisotropic etching using, for example, KOH is performed. As a result, the semiconductor substrate 1 shown in FIG. 5 is obtained. The main surface 11 and the top surface 130 are (100) surfaces. The first inclined side surface 131 and the second inclined side surface 132 are inclined surfaces formed by anisotropic etching, and the angle formed with the main surface 11 is 54.7 degrees, respectively. In addition, unlike this method, the semiconductor substrate 1 may be formed by cutting or the like.

Next, as shown in FIG. 6, the insulating layer 2 is formed. The insulating layer 2 is formed by depositing SiO ₂ using, for example, CVD. Further, the first opening 21 for the common electrode and the second opening 22 for the common electrode are formed by etching or the like.

Next, as shown in FIG. 7, the resistor layer 4 is formed. The resistance layer 4 is formed, for example, by forming a thin film of TaN on the insulating layer 2 by sputtering.

Next, the wiring layer 3 that covers the resistor layer 4 is formed. The wiring layer 3 is formed by forming a layer made of Cu by, for example, plating or sputtering. Further, the Ti layer may be formed before the Cu layer is formed. Then, by performing the selective etching of the wiring layer 3 and the selective etching of the resistor layer 4, the wiring layer 3 and the resistor layer 4 shown in FIG. 8 can be obtained. The wiring layer 3 has a plurality of individual electrodes 31 and a common electrode 32. The resistor layer 4 has a plurality of heat generating portions 41. Further, the common electrode 32 has a wiring side first through conduction portion 321 and a wiring side second through conduction portion 322. The resistor layer 4 has a resistance-side first through conduction portion 421 and a resistance-side second through conduction portion 422.

Then, as shown in FIG. 9, the insulating protective layer 5 is formed. The formation of the insulating protective layer 5 is performed, for example, by depositing SiO ₂ on the insulating layer 2, the wiring layer 3, and the resistor layer 4 using CVD, and then performing etching or the like.

Next, as shown in FIG. 10, the conductive protective layer 6 is formed. Further, a pad 381 for a control element and a pad 382 for a wiring member are formed. Next, as shown in FIG. 11, the wiring member 92 is joined to the wiring member pad 382. Then, the semiconductor substrate 1 is bonded to the support member 91 by using the bonding layer 919, and then the protective resin 8 is formed. By going through the above steps, the thermal print head A1 can be obtained.

Next, the operation of the thermal print head A1 will be described.

According to this embodiment, the semiconductor substrate 1 is formed with a convex portion 13. The plurality of heat generating portions 41 overlap with the convex portions 13 in the z-view in the thickness direction. This makes it possible to press the portion including the plurality of heat generating portions 41 against the print medium 992 with a higher pressure. Further, it is possible to suppress the interference between the printing medium 992 and a plurality of parts of the thermal print head A1 other than the heat generating portions 41. Therefore, printing can be performed more reliably by the thermal print head A1.

The convex portion 13 has a top surface 130, a first inclined side surface 131, and a second inclined side surface 132. The top surface 130 is a plane parallel to the main surface 11, and is preferable as a portion for forming a plurality of heat generating portions 41. The configuration having the first inclined side surface 131 and the second inclined side surface 132 is suitable for forming the wiring layer 3 and the resistor layer 4 so as to straddle them.

Further, the control element 7 is arranged in the second region 112, and is located on the main surface 11 side of the conductive protective layer surface S6 in the thickness direction z. This makes it possible to avoid interference between the control element 7 and the print medium 992. Further, it is preferable that the control element 7 is located on the main surface 11 side of the resistor layer surface S4 in the thickness direction z in order to avoid interference between the control element 7 and the print medium 992.

Further, the conduction path for energizing the plurality of heat generating portions 41 includes the semiconductor substrate 1. Since conduction is achieved by the semiconductor substrate 1, it is not necessary to form a corresponding portion as a part of the wiring layer 3. This makes it possible to reduce the area of the wiring layer 3 to be provided on the main surface 11 side. As a result, it is possible to expand the area for forming the wiring layer 3, and it is easier to form the wiring layer 3 in response to the miniaturization and narrowing of the pitch of the plurality of heat generating portions 41. Can be done. Therefore, it is possible to improve the fineness of printing.

Further, the semiconductor substrate 1 is conductive with the common electrode 32. The common electrode 32 is a portion that conducts with all of the plurality of heat generating portions 41. Therefore, the semiconductor substrate 1 is not forced to be divided into a plurality of portions insulated from each other.

The semiconductor substrate 1 is in contact with the wiring side first through conduction portion 321 and the wiring side second through conduction portion 322 through the common electrode first opening 21 and the common electrode second opening 22. The first opening 21 for the common electrode, the second opening 22 for the common electrode, the first through conduction portion 321 on the wiring side, and the second through conduction portion 322 on the wiring side sandwich a plurality of heat generating portions 41 in the sub-scanning direction y. With such an arrangement, the portion of the conduction path formed by the semiconductor substrate 1 is shaped to bypass the plurality of heat generating portions 41 in the thickness direction z. This is preferable for downsizing and narrowing the pitch of the plurality of heat generating portions 41.

Further, the portion of the conduction path formed by the semiconductor substrate 1 overlaps the plurality of control elements 7 in the thickness direction z-view. This makes it possible to suppress interference between the wiring layer 3 and the plurality of control elements 7.

The first opening 21 for the common electrode extends long in the main scanning direction x. As a result, the contact resistance between the wiring layer 3 and the semiconductor substrate 1 can be reduced.

The insulating protective layer 5 is conductive with the common electrode 32 of the wiring layer 3 through the protective layer penetrating conductive portion 61. The insulating protective layer 5 is a portion that rubs against the print medium 992, and is easily charged with static electricity. It is possible to appropriately release this charged charge to the common electrode 32 of the wiring layer 3.

12 to 14 show modifications and other embodiments of the present invention. In these figures, the same or similar elements as those in the above embodiment are designated by the same reference numerals as those in the above embodiment.

FIG. 12 shows a modified example of the thermal print head A1. In this modification, the insulating layer 2 has a raised portion 29. The raised portion 29 is formed on the top surface 130 of the convex portion 13. The raised portion 29 is a portion thicker than the portion of the insulating layer 2 other than the raised portion 29, and extends long in the main scanning direction x. The plurality of heat generating portions 41 of the resistor layer 4 are provided on the raised portion 29.

FIG. 13 shows a thermal printhead based on the second embodiment of the present invention. The thermal print head A2 of the present embodiment has a different configuration of the semiconductor substrate 1 from the thermal print head A1 described above. In the present embodiment, the convex portion 13 of the semiconductor substrate 1 has a first auxiliary inclined side surface 133 and a second auxiliary inclined side surface 134.

The first auxiliary inclined side surface 133 is interposed between the top surface 130 and the first inclined side surface 131. Further, the angle formed by the first auxiliary inclined side surface 133 with the top surface 130 is smaller than the angle formed by the first inclined side surface 131 and the top surface 130. The second auxiliary inclined side surface 134 is interposed between the top surface 130 and the second inclined side surface 132. The angle formed by the top surface 130 of the second auxiliary inclined side surface 134 is smaller than the angle formed by the second inclined side surface 132 and the top surface 130.

FIG. 14 shows one step in an example of a method for manufacturing the thermal print head A2. The thermal print head A2 is manufactured by the same manufacturing method as those shown in FIGS. 5 to 11, and FIG. 14 shows a process corresponding to FIG. For example, after the semiconductor substrate 1 shown in FIG. 5 is formed by etching the semiconductor substrate 1 with KOH, the boundary between the top surface 130 and the first inclined side surface 131 and the second inclined side surface 132 is formed. Etching is performed as a target. As a result, the first auxiliary inclined side surface 133 and the second auxiliary inclined side surface 134 described above are formed.

Even with such an embodiment, printing can be performed more reliably. Further, the boundary portion between the top surface 130 and the first auxiliary inclined side surface 133 and the second auxiliary inclined side surface 134, the boundary portion between the first auxiliary inclined side surface 133 and the first inclined side surface 131, and the second auxiliary inclined side surface 134 and the first. 2 It is possible to loosen the angle of the boundary portion with the inclined side surface 132. As a result, it is possible to prevent the wiring layer 3 and the resistor layer 4 straddling these portions from being unintentionally damaged.

The thermal print head according to the present invention is not limited to the above-described embodiment. The specific configuration of each part of the thermal print head according to the present invention can be freely redesigned.

A1, A2: Thermal printhead 1: Semiconductor substrate 2: Insulation layer 3: Wiring layer 4: Resistor layer 5: Insulation protective layer 6: Conductive protective layer 7: Control element 8: Protective resin 11: Main surface 12: Back surface 13: Convex portion 21: First opening for common electrode 22: Second opening for common electrode 29: Raised portion 31: Individual electrode 32: Common electrode 41: Heat generating portion 51: Opening for conductive protective layer 52: Control element Opening 53: Opening for wiring member 61: Protective layer penetrating conductive portion 71: Control element electrode 79: Conductive bonding material 91: Support member 92: Wiring member 111: First region 112: Second region 130: Top surface 131: 1st inclined side surface 132: 2nd inclined side surface 133: 1st auxiliary inclined side surface 134: 2nd auxiliary inclined side surface 321: Wiring side 1st through conductive portion 322: Wiring side 2nd through conductive portion 381: Control element pad 382: Wiring member pad 421: Resistance side first through conducting part 422: Resistance side second through conducting part 911: Recessed portion 919: Bonding layer 921: Resin layer 922: Wiring layer 923: Protective layer 991: Platen roller 992: Printing medium S4 : Resistor layer surface S6: Conductive protective layer surface x: Main scanning direction y: Sub-scanning direction z: Direction

Claims (18)

With a semiconductor substrate,
A resistor layer supported by the semiconductor substrate and having a plurality of heat generating portions arranged in the main scanning direction to generate heat by energization.
A wiring layer supported by the semiconductor substrate and included in the conduction path for energizing the plurality of heat generating portions.
A thermal printhead including an insulating layer provided between the semiconductor substrate, the wiring layer, and the resistor layer.
The semiconductor substrate has a main surface and a back surface facing opposite to each other in the thickness direction, and a convex portion protruding from the main surface in the thickness direction and extending long in the main scanning direction.
The main surface has a first region and a second region that are separated from each other in the sub-scanning direction with the convex portion interposed therebetween.
The convex portion is interposed between the top surface parallel to the main surface and separated from the main surface in the thickness direction, and between the top surface and the first region, and with respect to the main surface. It has a first inclined side surface that is inclined and a second inclined side surface that is interposed between the top surface and the second region and is inclined with respect to the main surface.
The insulating layer has a first portion formed on the top surface and extending in the main scanning direction, and two second portions formed on the top surface and located on both sides of the first portion in the sub-scanning direction. Including the part
The thickness of the first part is thicker than the thickness of the second part.
The plurality of heat generating portions are characterized in that they overlap with the first portion in the thickness direction view.
Thermal print head. The first part has a first surface that is parallel to the main surface and is separated from the main surface in the thickness direction.
The thermal print head according to claim 1, wherein the plurality of heat generating portions overlap with the first surface in the thickness direction view. The thermal print head according to claim 2, wherein the heat generating portion is in contact with both ends of the first surface in the sub-scanning direction. The thermal print head according to claim 3, wherein the heat generating portion is in contact with both ends of the first portion in the sub-scanning direction. The thermal print head according to claim 4, wherein the wiring layer includes a portion formed on the second part. The thermal print head according to any one of claims 1 to 5, wherein the conduction path includes the semiconductor substrate. The wiring layer has a plurality of individual electrodes connected to the plurality of heat generating portions separately, and a portion arranged on the opposite side of the plurality of individual electrodes with the plurality of heat generating portions interposed therebetween. It has a common electrode that conducts with the heat generating part of
The thermal print head according to claim 6, wherein the common electrode and the semiconductor substrate are conductive. The thermal printhead according to claim 7, further comprising an insulating protective layer that covers the wiring layer and the resistor layer. The thermal print head according to claim 8, wherein the insulating layer has a first opening for a common electrode that conducts the semiconductor substrate and the common electrode. The insulating layer is located on the side opposite to the first opening for the common electrode in the sub-scanning direction with the plurality of heat generating portions interposed therebetween, and has a second opening for the common electrode that conducts the semiconductor substrate and the individual electrodes. The thermal print head according to claim 9. A plurality of control elements that conduct the wiring layer and individually energize the plurality of heat generating portions are provided.
The thermal print head according to claim 10, wherein the second opening for the common electrode overlaps with the control element in the thickness direction view. The thermal printhead according to claim 11, wherein the insulating protective layer has an opening for a control element that exposes at least a part of each of the plurality of individual electrodes and the common electrode. 12. The thermal according to claim 12, wherein the insulating protective layer is located on the side opposite to the plurality of heat generating portions with respect to the control element in the sub-scanning direction, and has an opening for a wiring member that exposes the wiring layer. Print head. The thermal print head according to any one of claims 11 to 13, further comprising a conductive protective layer that overlaps with the plurality of heat generating portions and is laminated on the insulating protective layer in the thickness direction. The thermal print head according to claim 14, wherein the conductive protective layer is made of TiN. The thermal print head according to any one of claims 1 to 15, wherein the semiconductor substrate is made of a material in which Si is doped with a metal element. The thermal print head according to any one of claims 1 to 16, wherein the resistor layer is made of TaN. The thermal print head according to any one of claims 1 to 17, wherein the wiring layer is made of Cu.

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