JP2021115717A - Manufacturing method for thermal print head and thermal print head - Google Patents

Abstract

To provide a manufacturing method for a thermal print head that can form an electrode layer in which a conduction path is properly configured.SOLUTION: A manufacturing method for a thermal print head A1 includes a substrate preparing step, a resistor layer forming step, and an electrode layer forming step. An electrode layer 3 includes a plurality of individual electrode belt-like parts 38 arranged at a pitch width Pt2 and a plurality of connection parts 37 arranged at a pitch width Pt3 smaller than the pitch width Pt2. A substrate 1 includes a first region 10A and a second region 10B. The electrode layer forming step includes: a first patterning step of forming patterns of the plurality of individual electrode belt-like parts 38 in the first region 10A by screen printing; and a second patterning step of forming patterns of the plurality of connection parts 37 in the second region 10B, by a patterning technique (dispenser coating for instance) that can perform patterning with accuracy higher than accuracy in the screen printing.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a method for manufacturing a thermal printhead and a thermal printhead.

Patent Document 1 discloses an example of a conventional thermal print head. The thermal printhead disclosed in the document includes a substrate, an electrode layer, a resistor layer and a protective layer. The substrate is a plate-shaped member made of an insulating material. The electrode layer is formed on the substrate and constitutes a current path for selectively passing a current through the resistor layer. The electrode layer has a common electrode and a plurality of individual electrodes. The common electrode and the individual electrode are electrically opposite electrodes. The portion of the resistor layer sandwiched between a part of the common electrode and the individual electrode in the main scanning direction becomes the heat generating portion. The protective layer is for protecting the electrode layer, and is made of, for example, glass.

In recent years, as the thermal print head has become smaller and has higher image quality, the pattern of the electrode layer has become finer. Even when such high-definition patterning is required, it is preferable that the electrode layer does not break or short-circuit, and the conduction path is appropriately configured so that the electrode layer and the resistor layer are sufficiently conductive. ..

Japanese Unexamined Patent Publication No. 10-16268

The present disclosure has been conceived in view of the above circumstances, and an object of the present disclosure is to provide a method for manufacturing a thermal printhead capable of forming an electrode layer having an appropriately configured conduction path.

The method for manufacturing a thermal printhead provided by the first aspect of the present disclosure includes a substrate preparation step of preparing a substrate and a resistor layer including a plurality of heat generating portions arranged in the main scanning direction on the substrate. A step of forming a resistor layer to be formed and a step of forming an electrode layer for forming an electrode layer for energizing the resistor layer are included, and the electrode layers are arranged in a first pitch width. The substrate includes one portion and a plurality of second portions arranged with a second pitch width smaller than the first pitch width, and the substrate is formed by the plurality of first portions when viewed in the thickness direction of the substrate. The first region to be formed and the second region in which the plurality of second portions are formed when viewed in the thickness direction are included, and the electrode layer forming step is performed by screen printing on the plurality of said first regions. The second patterning in which the pattern of the plurality of second parts is formed in the second region by the first patterning step of forming the pattern of the first part and the patterning technique capable of patterning with a higher definition than the screen printing. It is characterized by including a process.

The thermal printhead provided by the second aspect of the present disclosure includes a substrate and a plurality of heat generating portions arranged in the main scanning direction, and the resistor layer formed on the substrate and the resistor layer. The electrode layer includes a plurality of first parts, a plurality of second parts, and a plurality of bonding parts, and the plurality of first parts are subordinate to each other. The plurality of second portions are strip-shaped extending in the scanning direction and arranged in the main scanning direction with the first pitch width, and each of the plurality of second portions is strip-shaped extending in the sub-scanning direction and the first pitch width. Arranged in the main scanning direction with a second pitch width smaller than that, the plurality of bonding portions are each connected to the drive IC via a wire, and each is connected to each of the plurality of second portions. The plurality of first parts are patterned by screen printing, and the plurality of second parts are patterned by a method capable of patterning with a higher definition than the screen printing. ..

According to the method for manufacturing a thermal printhead of the present disclosure, an electrode layer having an appropriately configured conduction path can be formed.

It is a top view which shows the thermal print head which concerns on 1st Embodiment. It is sectional drawing which follows the line II-II of FIG. It is an enlarged plan view of a main part which enlarged a part of FIG. FIG. 3 is an enlarged cross-sectional view of a main part along the line IV-IV of FIG. It is sectional drawing which shows one step of the manufacturing method of the thermal printhead which concerns on 1st Embodiment. It is a top view which shows one step of the manufacturing method of the thermal print head which concerns on 1st Embodiment. It is sectional drawing which shows one step of the manufacturing method of the thermal printhead which concerns on 1st Embodiment. It is a top view which shows one step of the manufacturing method of the thermal print head which concerns on 1st Embodiment. It is sectional drawing which shows one step of the manufacturing method of the thermal printhead which concerns on 1st Embodiment. It is sectional drawing which shows one step of the manufacturing method of the thermal printhead which concerns on 1st Embodiment. It is sectional drawing which shows the thermal print head which concerns on the modification of 1st Embodiment. It is a top view which shows the thermal print head which concerns on 2nd Embodiment. It is sectional drawing which follows the XIII-XIII line of FIG. It is a top view which shows one step of the manufacturing method of the thermal print head which concerns on 2nd Embodiment. It is sectional drawing which shows the thermal print head which concerns on the modification of 2nd Embodiment. It is sectional drawing which shows the thermal print head which concerns on the modification of 2nd Embodiment. It is a top view which shows the thermal print head which concerns on 3rd Embodiment. FIG. 6 is a cross-sectional view taken along the line XVIII-XVIII of FIG. It is a top view which shows one step of the manufacturing method of the thermal print head which concerns on 3rd Embodiment. FIG. 5 is a cross-sectional view taken along the line XX-XX of FIG. It is sectional drawing which shows one step of the manufacturing method of the thermal print head which concerns on 3rd Embodiment. It is a top view which shows one step of the manufacturing method of the thermal print head which concerns on 3rd Embodiment. FIG. 2 is a cross-sectional view taken along the line XXIII-XXIII of FIG. It is a top view which shows one step of the manufacturing method of the thermal print head which concerns on 3rd Embodiment. It is sectional drawing which follows the XXV-XXV line of FIG. It is an enlarged sectional view of the main part which shows the thermal print head which concerns on a modification.

The method for manufacturing the thermal printhead and the preferred embodiment of the thermal printhead of the present disclosure will be described below with reference to the drawings. Terms such as "first," "second," and "third" in the present disclosure are used merely as labels and are not necessarily intended to permutate those objects.

In the present disclosure, "something A is formed on a certain thing B" and "something A is formed on a certain thing B" means "there is a certain thing A" unless otherwise specified. It includes "being formed directly on the object B" and "being formed on the object B with the object A while interposing another object between the object A and the object B". Similarly, "something A is placed on something B" and "something A is placed on something B" means "something A is placed on something B" unless otherwise specified. It includes "being placed directly on B" and "being placed on a certain thing B while having another thing intervening between a certain thing A and a certain thing B". Similarly, "something A is located on something B" means "something A is in contact with something B and some thing A is on something B" unless otherwise specified. "What you are doing" and "The thing A is located on the thing B while another thing is intervening between the thing A and the thing B". In addition, "something A overlaps with some thing B when viewed in a certain direction" means "something A overlaps with all of some thing B" and "something A overlaps" unless otherwise specified. "Overlapping a part of a certain object B" is included.

<First Embodiment>
1 to 4 show the thermal print head A1 according to the first embodiment. The thermal print head A1 includes a substrate 1, an electrode layer 3, a resistor layer 4, a protective layer 5, a plurality of drive ICs 71, a sealing resin 72, a plurality of connectors 73, a wiring board 74, and a heat radiating member 75. The thermal print head A1 is incorporated in a printer that prints on the print medium 82. As shown in FIG. 2, the print medium 82 is sandwiched between the thermal print head A1 and the platen roller 81, and is conveyed in the sub-scanning direction by the rotational movement of the platen roller 81. Examples of the print medium 82 include thermal paper for producing a barcode sheet and 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 plan view of a main part obtained by enlarging a part of FIG. FIG. 4 is an enlarged cross-sectional view of a main part along the line IV-IV of FIG. In FIG. 1, the protective layer 5 and the wire 61 are omitted, and the sealing resin 72 is shown by an imaginary line (dashed line). In FIG. 3, the protective layer 5 is omitted. For convenience of understanding, in FIGS. 1 to 4, the main scanning direction is the x direction, the sub scanning direction is the y direction, and the thickness direction of the substrate 1 is the z direction. At the time of printing, the print medium is fed in the direction indicated by the arrow in the drawing in the sub-scanning direction y. In the sub-scanning direction y, the direction indicated by the arrow in the figure is the downstream direction, and the opposite direction is the upstream direction. Further, in the thickness direction z, the direction indicated by the arrow in the figure is upward, and the opposite direction is downward.

In the thermal print head A1, the substrate 1 and the wiring board 74 are adjacent to each other in the sub-scanning direction y as shown in FIG. 2, and each of them is mounted on the heat radiating member 75. The wiring board 74 is a board in which, for example, a base material layer made of glass epoxy resin and a wiring layer made of Cu (copper) or the like are laminated. The heat radiating member 75 is made of a metal such as Al (aluminum). As shown in FIG. 2, the drive IC 71 on the board 1 and the wiring of the wiring board 74 are connected by a wire 61. A connector 73 is provided on the wiring board 74. The thermal print head A1 is formed with a plurality of heat generating portions 41 arranged in the main scanning direction x according to the configuration described in detail later. The heat generating unit 41 is selectively generated and driven by the drive IC 71 according to a print signal transmitted from the outside via the connector 73. As shown in FIG. 2, the thermal print head A1 presses the printing medium 82 against the heat generating portion 41 by the platen roller 81, and prints on the printing medium 82 due to the heat generated by the heat generating portion 41. The thermal print head A1 may not include the wiring board 74, and the connector 73 may be mounted on the board 1.

As shown in FIG. 1, the substrate 1 has a plate shape extending long in the main scanning direction x. The substrate 1 supports the electrode layer 3, the resistor layer 4, the protective layer 5, and the drive IC 71. The substrate 1 includes a first region 10A and a second region 10B in the thickness direction z-view. The second region 10B is a region in which the electrode layer 3 is formed with a relatively higher definition than the first region 10A. The electrode layer 3 formed in the first region 10A is patterned by, for example, screen printing, and the electrode layer 3 formed in the second region 10B is a patterning method capable of patterning with a higher fineness than screen printing (this embodiment). In the form, it is formed by dispenser application). The substrate 1 includes a base material 11 and a glaze layer 12.

The base material 11 is made of, for example _{, a ceramic such as AlN (aluminum nitride), Al 2} O ₃ (alumina), or zirconia. The base material 11 has, for example, a thickness of 0.6 mm or more and 1.0 mm or less. The base material 11 has a rectangular shape that extends long in the main scanning direction x in the thickness direction z. The base material 11 has a main surface 11a. The main surface 11a is the upper surface of the base material 11. The main surface 11a faces upward in the thickness direction z.

The glaze layer 12 is formed on the base material 11. The glaze layer 12 covers the main surface 11a. The glaze layer 12 is made of a glass material such as amorphous glass. The glaze layer 12 includes a partial glaze 121 and a glass layer 122. The glaze layer 12 may not include the glass layer 122 and may be composed of only the partial glaze 121. Alternatively, the substrate 1 may not include the glaze layer 12.

The partial glaze 121 extends long in the main scanning direction x. The partial glaze 121 bulges in the thickness direction z in the main scanning direction x-view. As shown in FIG. 4, the partial glaze 121 has an arcuate cross section (yz cross section) in a plane orthogonal to the main scanning direction x. The partial glaze 121 is provided in order to facilitate pressing the heat-generating portion (heat-generating portion 41 described later) of the resistor layer 4 against the printing medium 82. Further, the partial glaze 121 is provided as a heat storage layer for accumulating heat from the heat generating portion 41. The partial glaze 121 has a dimension (maximum dimension) in the thickness direction z larger than that of the glass layer 122.

The glass layer 122 is formed adjacent to the partial glaze 121 and has a flat upper surface. The glass layer 122 overlaps a part of the partial glaze 121. The thickness of the glass layer 122 is, for example, about 2.0 μm.

In the glaze layer 12, the partial glaze 121 is made of a glass material having a softening point of, for example, 800 ° C. or higher and 850 ° C. or lower, and the glass layer 122 is made of a glass material having a softening point of, for example, about 680 ° C. That is, the glass material forming the glass layer 122 has a lower softening point than the glass material forming the partial glaze 121. The glass material forming the partial glaze 121 and the glass material forming the glass layer 122 may have the same softening point.

The electrode layer 3 is for forming a path for energizing the resistor layer 4, and is formed of a conductive material. The electrode layer 3 is made of registered Au (gold) to which, for example, rhodium, vanadium, bismuth, silicon or the like is added as an additive element. The electrode layer 3 may have a configuration in which a plurality of Au layers are laminated. Further, the electrode layer 3 may be configured by laminating a Cu layer and a Ti layer, or may be composed of only a Cu layer. The thickness of the electrode layer 3 is, for example, 0.6 μm or more and 1.2 μm or less. The electrode layer 3 is formed on the glaze layer 12. As shown in FIGS. 3 and 4, the electrode layer 3 includes a common electrode 33 and a plurality of individual electrodes 36.

As shown in FIG. 3, the common electrode 33 has a plurality of common electrode strips 34 and connecting portions 35. The connecting portion 35 is arranged near the downstream end edge of the substrate 1 in the sub-scanning direction y, and has a strip shape extending in the main scanning direction x. In order to reduce the resistance value of the connecting portion 35, an Ag layer may be laminated on the connecting portion 35. Each of the plurality of common electrode band-shaped portions 34 extends from the connecting portion 35 in the sub-scanning direction y and is arranged in the main scanning direction x. The plurality of common electrode strips 34 include a base 341 and an extension 342, respectively. The plurality of bases 341 have a pitch width Pt1 (see FIG. 3) and are arranged in the main scanning direction x. The pitch width Pt1 is, for example, 10 μm or more and 100 μm or less (100 μm in one example). The width of each base 341 (dimension of the main scanning direction x) is, for example, 10 μm or more and 100 μm or less (60 μm in one example), and the separation distance between the two bases 341 adjacent to the main scanning direction x is, for example, 10 μm or more and 100 μm or less (60 μm or less). In one example, it is 40 μm). The extending portion 342 extends from the base portion 341 toward the resistor layer 4. The extending portion 342 has a long strip shape in the sub-scanning direction y in the thickness direction z. In the example shown in FIG. 3, the width of the extending portion 342 (dimension of the main scanning direction x) is smaller than the width of the base portion 341 (dimension of the main scanning direction x). As a result, it is possible to prevent the common electrode band-shaped portion 34 from being disconnected when the common electrode strip-shaped portion 34 is formed (during the pre-firing step after the pre-coating step described later). The width of the base portion 341 and the width of the extension portion 342 may be substantially the same. The plurality of extension portions 342 are arranged in the main scanning direction x with a pitch width Pt1 (see FIG. 3), similarly to the plurality of base portions 341. The width (dimension of the main scanning direction x) of each of the plurality of extending portions 342 is, for example, 10 μm or more and 100 μm or less (60 μm in one example), and the separation distance between the two extending portions 342 adjacent to the main scanning direction x is. For example, it is 10 μm or more and 100 μm or less (40 μm in one example).

The plurality of individual electrodes 36 are for partially conducting with the resistor layer 4, and have opposite polarities with respect to the common electrode 33. Each individual electrode 36 extends from the resistor layer 4 toward each drive IC 71. As shown in FIG. 3, the plurality of individual electrodes 36 are arranged in the main scanning direction x. Each individual electrode 36 includes an individual electrode band-shaped portion 38, a connecting portion 37, and a bonding portion 39.

As shown in FIG. 3, each of the plurality of individual electrode strips 38 extends from each connecting portion 37 in the sub-scanning direction y. The plurality of individual electrode strips 38 have a pitch width of Pt2 (see FIG. 3) and are arranged in the main scanning direction x. The plurality of individual electrode strips 38 include a base 381 and an extension 382, respectively. Each of the plurality of bases 381 has a long strip shape in the sub-scanning direction y in the thickness direction z-view. Each base 381 is connected to each connecting portion 37. The plurality of bases 381 have a pitch width Pt2 (see FIG. 3) and are arranged in the main scanning direction x. The pitch width Pt2 is the same as the pitch width Pt1, and is, for example, 10 μm or more and 100 μm or less (100 μm in one example). The width of each base 381 (dimension of the main scanning direction x) is, for example, 10 μm or more and 100 μm or less (60 μm in one example), and the separation distance between two bases 381 adjacent to each other in the main scanning direction x is, for example, 10 μm or more and 100 μm or less (60 μm or less). In one example, it is 40 μm). The extending portion 382 extends from the base portion 381 toward the resistor layer 4. The extending portion 382 has a long strip shape in the sub-scanning direction y in the thickness direction z. The extending portion 382 is located between two adjacent common electrode band-shaped portions 34 (common electrode 33). The width of the extending portion 382 (dimension of the main scanning direction x) is smaller than the width of the base portion 381 (dimension of the main scanning direction x). In the example shown in FIG. 3, this prevents disconnection from occurring in the individual electrode band-shaped portion 38 during the formation of the individual electrode strip-shaped portion 38 (during the pre-baking step after the pre-coating step described later). The width of the base portion 381 and the width of the extension portion 382 may be substantially the same. The plurality of extension portions 382 are arranged in the main scanning direction x with a pitch width Pt2 (see FIG. 3), similarly to the plurality of base portions 381. The width (dimension of the main scanning direction x) of each of the plurality of extending portions 382 is, for example, 10 μm or more and 100 μm or less (60 μm in one example), and the distance between the two extending portions 382 adjacent to each other in the main scanning direction x is. For example, it is 10 μm or more and 100 μm or less (40 μm in one example).

As shown in FIG. 3, each of the plurality of connecting portions 37 is a portion extending from each individual electrode strip-shaped portion 38 toward each bonding portion 39. The plurality of connecting portions 37 include a parallel portion 371 and an oblique portion 372, respectively. One end of each of the plurality of parallel portions 371 is connected to the bonding portion 39 and is along the sub-scanning direction y. The plurality of parallel portions 371 have a pitch width of Pt3 (see FIG. 3) and are arranged in the main scanning direction x. The pitch width Pt3 is, for example, 10 μm or more and 100 μm or less (40 μm in one example). The width of each parallel portion 371 (dimension of the main scanning direction x) is, for example, 10 μm or more and 100 μm or less (10 μm in one example), and the separation distance between two parallel portions 371 adjacent to the main scanning direction x is, for example, 10 μm or more and 100 μm. The following (30 μm in one example). Each of the plurality of skewed portions 372 is inclined with respect to the sub-scanning direction y. The plurality of skewed portions 372 are arranged with a pitch width Pt3, similarly to the plurality of parallel portions 371. Each of the plurality of skewed portions 372 is sandwiched between each parallel portion 371 and each individual electrode strip-shaped portion 38 in the sub-scanning direction y. Further, the plurality of individual electrodes 36 are integrated into any of the plurality of drive ICs 71. Therefore, the boundary between the parallel portion 371 and the skewed portion 372 on the one end side in the main scanning direction x in FIG. 3 and the boundary between the parallel portion 371 and the skewed portion 372 on the other end side are in the sub-scanning direction y. Misalignment L has occurred.

As shown in FIGS. 3 and 4, each connecting portion 37 includes a first edge portion 37a, a second edge portion 37b, and an intermediate portion 37c. The first edge portion 37a is an end portion on the downstream side in the sub-scanning direction y, and is a portion connected to each individual electrode band-shaped portion 38. The first edge portion 37a is formed on each individual electrode strip-shaped portion 38, and overlaps with each individual electrode strip-shaped portion 38 in the thickness direction z-view. The second edge portion 37b is an end portion on the upstream side in the sub-scanning direction y, and is a portion connected to each bonding portion 39. The second edge portion 37b is formed on each bonding portion 39 and overlaps each bonding portion 39 in the thickness direction z-view. The intermediate portion 37c connects the first end edge portion 37a and the second end edge portion 37b. The intermediate portion 37c does not overlap the first edge portion 37a and the second edge portion 37b in the sub-scanning direction y, but overlaps each individual electrode band-shaped portion 38 or each bonding portion 39.

As shown in FIG. 3, the bonding portion 39 is formed at the upstream end of the individual electrodes 36 in the sub-scanning direction y, and is connected to the connecting portion 37 (parallel portion 371). A wire 61 for connecting each individual electrode 36 and each drive IC 71 is bonded to each bonding portion 39. The plurality of bonding portions 39 includes a plurality of first bonding portions 39A and a plurality of second bonding portions 39B. The second bonding portion 39B is located on the side away from the resistor layer 4 with respect to the first bonding portion 39A in the sub-scanning direction y. The second bonding portion 39B is connected to a parallel portion 371 sandwiched between two adjacent first bonding portions 39A. With such a configuration, the plurality of bonding portions 39 are prevented from interfering with each other even though they are wider than most of the connecting portions 37.

Among the electrode layers 3, a plurality of common electrode band-shaped portions 34 (common electrode 33), a connecting portion 35 (common electrode 33), a plurality of individual electrode strip-shaped portions 38 (plurality of individual electrodes 36), and a plurality of bonding portions 39. (A plurality of individual electrodes 36) are formed in the first region 10A of the substrate 1. Further, in the electrode layer 3, a plurality of connecting portions 37 (plurality of individual electrodes 36) are formed in the second region 10B of the substrate 1. In the present embodiment, the plurality of common electrode strips 34 and the plurality of individual electrode strips 38 correspond to the "plurality of first parts" described in the claims. Further, the plurality of connecting portions 37 correspond to the "plurality of second portions" described in the claims. Since the forming method is different between the plurality of first portions (plurality of common electrode strips 34, plurality of individual electrode strips 38 and plurality of bonding portions 39) and the plurality of second portions (plurality of connecting portions 37), The edge of the plurality of first portions (for example, the edge extending in the sub-scanning direction y of each individual electrode strip 38) and the edge of the plurality of second portions (for example, the edge extending in the sub-scanning direction y of each connecting portion 37). ) Is different in linearity. The shape and arrangement of each part of the electrode layer 3 are not particularly limited, and various configurations can be made. Further, the material of each part of the electrode layer 3 is not limited.

The resistor layer 4 has a higher resistivity than the material constituting the electrode layer 3. The resistor layer 4 is made of, for example, ruthenium oxide. The resistor layer 4 is formed on the partial glaze 121 as shown in FIG. As shown in FIGS. 1 and 3, the resistor layer 4 has a strip shape extending in the main scanning direction x in the thickness direction z-view. The resistor layer 4 intersects each extension portion 342 of the plurality of common electrode band-shaped portions 34 (common electrode 33) and each extension portion 382 of the plurality of individual electrode strip-shaped portions 38 (plurality of individual electrodes 36). There is. The resistor layer 4 is laminated on the side opposite to the substrate 1 with respect to the plurality of common electrode strips 34 and the plurality of individual electrode strips 38. A portion of the resistor layer 4 sandwiched between each common electrode band-shaped portion 34 and each individual electrode strip-shaped portion 38 is referred to as a heat generating portion 41. The plurality of heat generating portions 41 generate heat when they are partially energized by the electrode layer 3. Print dots are formed by the heat generated by each heat generating portion 41. The plurality of heat generating portions 41 are arranged in the main scanning direction x. When the dimensions of the main scanning direction x of the substrate 1 are the same, the larger the number of the plurality of heat generating portions 41 arranged in the main scanning direction x, the larger the dot density of the thermal print head A1. The thickness of the resistor layer 4 is, for example, 3 μm or more and 6 μm or less. The material and thickness of the resistor layer 4 are not limited. In the example shown in FIG. 4, the resistor layer 4 is formed on the top of the partial glaze 121, but it does not have to be formed on the top of the partial glaze 121, and is formed on the partial glaze 121. Just do it.

The protective layer 5 is for protecting the electrode layer 3, the resistor layer 4, and the like. However, the protective layer 5 exposes a region including a plurality of bonding portions 39 of the plurality of individual electrodes 36. The protective layer 5 is made of, for example, amorphous glass. As the protective layer 5, a first layer made of amorphous glass and a second layer made of, for example, SiAlON may be laminated. SiAlON is a silicon nitride-based engineering ceramic in which alumina (Al ₂ O ₃ ) and silica (SiO _{2 ) are combined with silicon nitride (Si 3} N _4). The second layer is formed, for example, by sputtering. As the second layer, SiC (silicon carbide) may be adopted instead of SiAlON.

As shown in FIG. 4, the protective layer 5 includes a first covering portion 51 and a second covering portion 52. The first covering portion 51 is a portion of the protective layer 5 that overlaps the partial glaze 121 in the z-view in the thickness direction. The first covering portion 51 is formed on the partial glaze 121. The first covering portion 51 includes a raised portion 511. The raised portion 511 overlaps the resistor layer 4 (each heat generating portion 41) in the z-view in the thickness direction. Since the resistor layer 4 is arranged so as to be raised with respect to each surface of the electrode layer 3 or the partial glaze 121, the raised portion 511 has a raised shape along the resistor layer 4. The second covering portion 52 is a portion of the protective layer 5 that does not overlap the partial glaze 121 in the thickness direction z-view. The second covering portion 52 is arranged at both ends of the sub-scanning direction y of the first covering portion 51 in the thickness direction z-view. The second covering portion 52 on the upstream side in the sub-scanning direction y is formed in a region extending from the downstream end edge of the first covering portion 51 in the sub-scanning direction y to the front of the plurality of bonding portions 39.

The drive IC 71 partially heats the resistor layer 4 by selectively energizing a plurality of individual electrodes 36. The drive IC 71 is provided with a plurality of pads. The pad of the drive IC 71 and the plurality of individual electrodes 36 are connected to each other via a plurality of wires 61 joined to each other. The wire 61 is made of Au. As shown in FIGS. 1 and 2, the drive IC 71 and the wire 61 are covered with the sealing resin 72. The sealing resin 72 is insulating and is made of, for example, a black soft resin. Further, the drive IC 71 and the connector 73 are connected by a signal line (not shown).

Next, an example of a method for manufacturing the thermal print head A1 will be described with reference to FIGS. 5 to 10. 5 to 10, FIGS. 6 and 8 are plan views of a main part showing one step of the manufacturing method of the thermal print head A1, and correspond to FIG. The other figures are cross-sectional views of a main part showing one step of the manufacturing method of the thermal print head A1, and correspond to FIG.

First, the substrate 1 shown in FIG. 5 is prepared. The step of preparing the substrate 1 (the substrate preparation step) includes a base material preparation step and a glaze layer forming step. In the base material preparation step, for example, a base material 11 made of ceramic is prepared. As the ceramic material, for example AlN, Al ₂ O _3, may be any of such zirconia. The base material 11 has a main surface 11a facing upward in the thickness direction z. In the glaze layer forming step, the glaze layer 12 is formed on the main surface 11a of the base material 11. The step of forming the glaze layer 12 includes a partial glaze forming step of forming the partial glaze 121 and a glass layer forming step of forming the glass layer 122. In the partial glaze forming step, the glass paste constituting the partial glaze 121 is screen-printed, for example, and fired at a firing temperature of, for example, 800 ° C. or higher and 850 ° C. or lower. As a result, the partial glaze 121 is formed. In the glass layer forming step, the glass paste constituting the glass layer 122 is screen-printed, for example, and the glass paste is fired at a firing temperature of, for example, about 680 ° C. As a result, the glass layer 122 is formed. Each firing temperature in the partial glaze forming step and the glass layer forming step is appropriately changed based on each softening point of the glass paste constituting the partial glaze 121 and the glass paste constituting the glass layer 122.

Next, the electrode layer 3 is formed on the substrate 1. The step of forming the electrode layer 3 (electrode layer forming step) includes a pre-coating step, a pre-baking step, a trailing coating step, and a trailing firing step.

In the electrode layer forming step, first, a preliminary coating step is performed. In the pre-coating step, as shown in FIG. 6, the conductive paste 30A is applied to the first region 10A of the substrate 1. The conductive paste 30A is, for example, a registered Au paste. The pre-coating step is performed, for example, by screen printing. In the electrode layer 3, the conductive paste 30A has a plurality of common electrode strips 34 and connecting portions 35 (common electrodes 33), and a plurality of individual electrode strips 38 and a plurality of bonding portions 39 (plural) in the electrode layer 3. It is formed to have substantially the same shape as each pattern shape with the individual electrode 36). That is, by the prior coating step, patterning is performed between the plurality of common electrode band-shaped portions 34 and the connecting portion 35 of the common electrode 33 and the plurality of individual electrode strip-shaped portions 38 and the plurality of bonding portions 39 of the plurality of individual electrodes 36. The prior coating step corresponds to the "first patterning step" described in the claims.

Next, a pre-baking step is performed. In the pre-baking step, the conductive paste 30A applied by the pre-coating step is fired. As a result, as shown in FIG. 7, a plurality of common electrode strips 34 and connecting portions 35 (common electrodes 33), a plurality of individual electrode strips 38 of the plurality of individual electrodes 36, and a plurality of bonding portions 39 (plural). The individual electrodes 36) are formed. In addition, a step of drying the conductive paste 30A may be further added between the pre-coating step and the pre-baking step.

Next, a subsequent coating step is performed. In the subsequent coating step, as shown in FIG. 8, the conductive paste 30B is applied to the second region 10B of the substrate 1. The conductive paste 30B is the same material as the conductive paste 30A, and is, for example, a resinate Au paste. The subsequent coating step is performed using, for example, a dispenser. The conductive paste 30B is formed in the electrode layer 3 into substantially the same shape as the pattern shape of the plurality of connecting portions 37 (plurality of individual electrodes 36) in the electrode layer 3 by the subsequent coating step. That is, the patterning of the plurality of connecting portions 37 is performed by the subsequent coating step. The second coating step corresponds to the "second patterning step" described in the claims.

Next, a subsequent coating step is performed. In the subsequent firing step, the conductive paste 30B applied by the subsequent coating step is fired. As a result, as shown in FIG. 9, a plurality of connecting portions 37 are formed. In addition, a step of drying the conductive paste 30B may be further added between the subsequent coating step and the subsequent firing step.

Next, the resistor layer 4 is formed as shown in FIG. In the step of forming the resistor layer 4 (resistor layer forming step), the resistor paste is screen-printed on the partial glaze 121. The resistor paste contains a resistor such as ruthenium oxide. The resistor paste is formed in a band shape extending in the main scanning direction x on the partial glaze 121, and intersects each common electrode band-shaped portion 34 (extending portion 342) and each individual electrode strip-shaped portion 38 (extending portion 382). do. Then, the screen-printed resistor paste is fired. As a result, the resistor layer 4 shown in FIG. 10 is formed.

Next, the protective layer 5 is formed. In the step of forming the protective layer 5 (protective layer forming step), the glaze layer 12, the electrode layer 3 (excluding the plurality of bonding portions 39) and the resistor exposed to the outside above the thickness direction z of the base material 11 The glass paste constituting the protective layer 5 is screen-printed on the layer 4. Then, the screen-printed glass paste is fired. As a result, the protective layer 5 is formed.

After that, the thermal print head A1 shown in FIGS. 1 to 4 is manufactured by performing assembly steps such as mounting the drive IC 71, bonding the wire 61, and attaching the substrate 1 and the wiring board 74 to the heat radiating member 75.

The actions and effects of the method for manufacturing the thermal print head A1 are as follows.

The method for manufacturing the thermal print head A1 includes an electrode layer forming step including a first patterning step (preceding coating step) and a second patterning step (posterior coating step). In the first patterning step, a plurality of patterns of the first part are formed by screen printing. In the present embodiment, as the plurality of first portions, for example, a pattern of a plurality of common electrode band-shaped portions 34, a plurality of individual electrode strip-shaped portions 38, and a plurality of bonding portions 39 is formed. In the second patterning step, a plurality of patterns of the second part are formed by a method capable of patterning with a higher definition than screen printing. In the present embodiment, as a plurality of second parts, for example, a pattern of a plurality of connecting parts 37 is formed. The plurality of first parts are arranged with the first pitch width (pitch widths Pt1 and Pt2), and even in patterning by screen printing, it is possible to form an appropriate pattern without short circuits or disconnections. On the other hand, the plurality of second parts are arranged with a second pitch width (pitch width Pt3) smaller than the first pitch width, and there is a possibility that a short circuit or disconnection may occur in patterning by screen printing. Therefore, the plurality of second parts are patterned by a method capable of patterning with a higher definition than screen printing. As a result, the plurality of second parts can form an appropriate pattern without short circuits or disconnections. Therefore, according to the method for manufacturing the thermal printhead A1, the electrode layer 3 having an appropriately configured conduction path can be formed.

In the method for manufacturing the thermal print head A1, a plurality of second parts are patterned by a subsequent coating step. In the subsequent coating step, the conductive paste 30B is coated on the second region 10B by coating with a dispenser. According to this configuration, a plurality of second parts can be patterned with higher definition than screen printing. Therefore, a plurality of second portions having a pattern shape finer than the plurality of first portions can be appropriately formed without causing a short circuit or disconnection. As a plurality of patterning methods for the second part, for example, a method of applying the conductive paste 30B by screen printing and then patterning by etching can be considered. However, this patterning method requires mask formation, etching, and mask removal by lithography, and there is a concern that the manufacturing cost will increase. Therefore, in the method for manufacturing the thermal print head A1, an increase in manufacturing cost is suppressed.

In the method for manufacturing the thermal print head A1, in the first patterning step (preceding coating step), a plurality of first parts are patterned by screen printing. Patterning by screen printing has lower definition than patterning by dispenser coating, but the manufacturing efficiency is high because the cycle time of coating (printing) is short. Therefore, in the method for manufacturing the thermal printhead A1, as compared with the case where all of the plurality of first parts and the plurality of second parts are patterned by dispenser coating, the conduction path is appropriately suppressed while suppressing a decrease in manufacturing efficiency. The configured electrode layer 3 can be formed.

In the production method according to the first embodiment, the electrode layer forming step is not limited to the above-mentioned method. For example, after the pre-coating step, the post-coating step is performed, and then the pre-firing step and the post-firing step are collectively performed. As a result, the electrode layer 3 may be formed. In this case, it is necessary to transfer the substrate 1 from the screen printing machine to the dispenser between the preceding coating step and the succeeding coating process. Due to the vibration generated during this transportation, the conductive paste 30A may flow out to an unintended place. Therefore, for example, if the conductive paste 30A is dried and then conveyed after the pre-coating step and before the subsequent coating step, the outflow can be suppressed. Further, for example, after the order of the preceding coating step and the succeeding coating step is changed to form a plurality of second portions (plurality of connecting portions 37), a plurality of first portions (plurality of individual electrode strips 38 and the like) may be formed. ) May be formed. That is, after applying the conductive paste 30B to the second region 10B by applying the dispenser, the conductive paste 30B is fired. Then, after applying the conductive paste 30A to the first region 10A by screen printing, the conductive paste 30A is fired. As a result, the electrode layer 3 may be formed. In this case, for example, the thermal print head A2 shown in FIG. 11 is formed. In the thermal print head A2 shown in FIG. 11, the first edge portion 37a of each connecting portion 37 is not formed on each individual electrode strip-shaped portion 38, but is formed between each individual electrode strip-shaped portion 38 and the substrate 1. It will be arranged between them. Further, the second edge portion 37b of each connecting portion 37 is not formed on each bonding portion 39, but is arranged so as to be interposed between each bonding portion 39 and the glass layer 122 (board 1). ..

<Second Embodiment>
12 and 13 show the thermal printhead B1 according to the second embodiment. FIG. 12 is a plan view showing the thermal print head B1 and corresponds to the enlarged plan view of the main part of FIG. FIG. 13 is a cross-sectional view taken along the line XIII-XIII of FIG. 12, which corresponds to an enlarged cross-sectional view of a main part of FIG.

As shown in FIGS. 12 and 13, the configuration of the electrode layer 3 of the thermal print head B1 is different from that of the thermal print head A1.

As shown in FIG. 12, the electrode layer 3 of the thermal print head B1 has a width of each connecting portion 37 (each individual electrode 36) larger than the width of each connecting portion 37 of the thermal print head A1. In the present embodiment, in the plurality of connecting portions 37, the plurality of parallel portions 371 and the plurality of skewed portions 372 are arranged with a pitch width Pt3 (see FIG. 12), respectively, similarly to the thermal print head A1. However, the width of each parallel portion 371 (dimension of the main scanning direction x) is, for example, 10 μm or more and 100 μm or less (30 μm in one example), and the separation distance between the two parallel portions 371 adjacent to the main scanning direction x is, for example, 10 μm. It is 100 μm or less (10 μm in one example). Similarly, the width of each skewed portion 372 is, for example, 10 μm or more and 100 μm or less (30 μm in one example), and the separation distance between two adjacent skewed portions 372 is, for example, 10 μm or more and 100 μm or less (10 μm in one example). be.

As shown in FIG. 12, of the plurality of parallel portions 371, the parallel portion 371 connected to the second bonding portion 39B includes the thin wire portion 371B. Each thin wire portion 371B is located on the upstream side in the sub-scanning direction y of the parallel portions 371 connected to each second bonding portion 39B, and is sandwiched between two adjacent first bonding portions 39A. The width (length in the main scanning direction x) of the thin line portion 371B is smaller than that of the other portions in each parallel portion 371.

As shown in FIG. 13, in each individual electrode 36, the connecting portion 37 is integrally formed with the individual electrode strip-shaped portion 38 and the bonding portion 39. The first edge portion 37a of each connecting portion 37 does not overlap with each individual electrode band-shaped portion 38 in the thickness direction z-view, and the second end edge portion 37b of each connecting portion 37 is in the thickness direction z-view. , Does not overlap with each bonding portion 39. In each connecting portion 37, the first edge portion 37a, the second edge portion 37b, and the intermediate portion 37c are in contact with the glass layer 122 (glaze layer 12), respectively.

In the present embodiment, among the electrode layers 3, the plurality of common electrode strips 34 (common electrodes 33) and the plurality of individual electrode strips 38 (plurality of individual electrodes 36) are located in the first region 10A of the substrate 1. It is formed. Further, in the electrode layer 3, a plurality of connecting portions 37 (plurality of individual electrodes 36) and a plurality of bonding portions 39 (plurality of individual electrodes 36) are formed in the second region 10B of the substrate 1. In the present embodiment, the plurality of common electrode strips 34 and the plurality of individual electrode strips 38 correspond to the "plurality of first parts" described in the claims. Further, the plurality of connecting portions 37 correspond to the "plurality of second portions" described in the claims.

Next, an example of a method for manufacturing the thermal print head B1 will be described with reference to FIG. FIG. 14 is a plan view showing one step of the manufacturing method of the thermal print head B1 and corresponds to FIG.

The method for manufacturing the thermal print head B1 is different from the method for manufacturing the thermal print head A1 in the electrode layer forming step. The electrode layer forming step in the present embodiment includes a coating step, a firing step, and a partial removal step.

In the electrode layer forming step of the present embodiment, first, a coating step is performed. In the coating step, the conductive paste 30C is applied to the substrate 1 prepared in the substrate preparation step. The conductive paste 30C is the same material as the conductive pastes 30A and 30B, and is, for example, a resinate Au paste. The coating process is performed by screen printing. In the coating step, as shown in FIG. 14, in the first region 10A, a conductive paste having substantially the same shape as the pattern shape of the plurality of common electrode band-shaped portions 34 and the connecting portion 35, and the plurality of individual electrode strip-shaped portions 38. 30C is formed, and a solid pattern is formed on the entire surface of the second region 10B. The coating step of the present embodiment includes a first coating step of applying the conductive paste 30C to the first region 10A and a second coating step of applying the conductive paste 30C to the second region 10B, and these first coating steps are performed. The process and the second coating process are performed collectively. The conductive paste 30C formed in the first region 10A by the first coating step is formed in substantially the same shape as the pattern shapes of the plurality of common electrode strips 34 and the connecting portions 35, and the plurality of individual electrode strips 38. Therefore, the first coating step performs patterning of the plurality of common electrode band-shaped portions 34 and the connecting portion 35, and the plurality of individual electrode strip-shaped portions 38 (plurality of the first portion).

Next, a firing step is performed. In the firing step, the conductive paste 30C applied by the coating step is fired. As a result, a fired body of the conductive paste 30C is formed. The firing steps of the present embodiment include a first firing step of firing the conductive paste 30C applied to the first region 10A and a second firing step of firing the conductive paste 30C (solid pattern) applied to the second region 10B. The first firing step and the second firing step are collectively performed including a firing step. In addition, a step of drying the conductive paste 30C may be further added between the coating step and the firing step.

Next, a partial removal step is performed. In the partial removal step, the solid pattern formed in the second region 10B is partially removed by laser processing. As a result, a plurality of connecting portions 37 and a plurality of bonding portions 39 are formed. Therefore, the pattern shape of the plurality of connecting portions 37 and the plurality of bonding portions 39 (plurality of second portions) is formed by the partial removing step.

In the present embodiment, the first coating step of applying the conductive paste 30C to the first region 10A corresponds to the "first patterning step" described in the claims. Further, the second coating step of applying the conductive paste 30C to the second region 10B corresponds to the "coating step" described in the claims, and the second coating of applying the conductive paste 30C to the second region 10B. The step including the step, the second firing step of firing the step, and the partial removing step corresponds to the "second patterning step" described in the claims.

After that, the thermal print head B1 is manufactured by performing the resistor layer forming step, the protective layer forming step, and the assembling step in the same manner as in the manufacturing method according to the first embodiment.

The actions and effects of the method for manufacturing the thermal print head B1 are as follows.

The method for manufacturing the thermal print head B1 includes an electrode layer forming step including a first patterning step and a second patterning step, similarly to the manufacturing method for the thermal print head A1. In the first patterning step, a plurality of patterns of the first part are formed by screen printing. In the present embodiment, for example, a plurality of common electrode band-shaped portions 34 and a plurality of individual electrode strip-shaped portions 38 are formed as the plurality of first portions. In the second patterning step, a plurality of patterns of the second part are formed by a method capable of patterning with a higher definition than screen printing. In the present embodiment, patterns of, for example, a plurality of connecting portions 37 and a plurality of bonding portions 39 are formed as the plurality of second portions. Therefore, the manufacturing method of the thermal print head C1 is the same as the manufacturing method of the thermal print head A1, by a method capable of patterning a plurality of second parts, which are difficult to pattern by screen printing, with higher definition than screen printing. Pattern. As a result, it is possible to form the electrode layer 3 in which the conduction path is appropriately configured.

In the method for manufacturing the thermal print head B1, a plurality of second parts are patterned by sequentially processing a coating step (second coating step), a firing step (second firing step), and a partial removal step. .. In the coating step (second coating step), the conductive paste 30C is applied to the second region 10B by screen printing to form a solid pattern on the entire surface of the second region 10B. In the firing step (second firing step), the conductive paste 30C in the solid pattern portion is fired to form a fired body of the conductive paste 30C. Then, in the partial removal step, the solid pattern is partially removed by laser processing to form a plurality of second part patterns. According to this configuration, a plurality of second parts can be patterned with higher definition than screen printing. Therefore, a plurality of second portions having a pattern shape finer than the plurality of first portions can be appropriately formed without causing a short circuit or disconnection.

The method for manufacturing the thermal print head B1 includes a coating step and a firing step. In the coating step, the first coating step of applying the conductive paste 30C to the first region 10A and the second coating step of applying the conductive paste 30C to the second region 10B are collectively performed by screen printing. The firing step includes a first firing step of firing the conductive paste 30C in the first region 10A and a second firing step of firing the conductive paste 30C in the second region 10B. According to this configuration, the conductive paste 30C can be applied and fired once, which is preferable in terms of improving production efficiency.

In the production method according to the second embodiment, the electrode layer forming step is not limited to the above-mentioned method. For example, the first coating step and the second coating step may be performed separately instead of collectively, and the first firing step and the second firing step may be performed separately instead of collectively. For example, the first coating step, the first firing step, the second coating step, the second firing step, and the partial removal step may be processed in this order. In this case, for example, the thermal print head B2 shown in FIG. 15 is formed. In the thermal print head B2 shown in FIG. 15, the first edge portion 37a of each connecting portion 37 is not integrally formed with each individual electrode strip-shaped portion 38, but is formed on each individual electrode strip-shaped portion 38. ing. Further, for example, the second coating step, the second firing step, the partial removal step, the first coating step, and the first firing step may be processed in this order. In this case, for example, the thermal print head B3 shown in FIG. 16 is formed. In the thermal print head B3 shown in FIG. 16, the first edge portion 37a of each connecting portion 37 is not integrally formed with each individual electrode strip-shaped portion 38, but is formed under each individual electrode strip-shaped portion 38. ing. That is, the first edge portion 37a of each connecting portion 37 is interposed between each individual electrode band-shaped portion 38 and the glass layer 122 (board 1).

<Third Embodiment>
17 and 18 show the thermal printhead C1 according to the third embodiment. FIG. 17 is a plan view showing the thermal print head C1 and corresponds to the enlarged plan view of the main part of FIG. FIG. 18 is a cross-sectional view taken along the line XVIII-XVIII of FIG. 17, which corresponds to an enlarged cross-sectional view of a main part of FIG.

As shown in FIGS. 17 and 18, the structure of the electrode layer 3 of the thermal print head C1 is different from that of the thermal print heads A1 and B1.

As shown in FIG. 18, in the electrode layer 3 of the thermal print head C1, each individual electrode 36 has a connecting portion 37 formed separately from the individual electrode strip-shaped portion 38 and integrally formed with the bonding portion 39. There is. The first edge portion 37a of each connecting portion 37 overlaps with each individual electrode strip-shaped portion 38 in the thickness direction z-view, and is located between each individual electrode strip-shaped portion 38 and the glass layer 122 (board 1). do. The second edge portion 37b of each connecting portion 37 does not overlap the bonding portion 39 in the thickness direction z view.

In the present embodiment, among the electrode layers 3, the plurality of common electrode strips 34 (common electrodes 33) and the plurality of individual electrode strips 38 (plurality of individual electrodes 36) are located in the first region 10A of the substrate 1. It is formed. Further, in the electrode layer 3, a plurality of connecting portions 37 (plurality of individual electrodes 36) and a plurality of bonding portions 39 (plurality of individual electrodes 36) are formed in the second region 10B of the substrate 1. In the present embodiment, the plurality of common electrode strips 34 and the plurality of individual electrode strips 38 correspond to the "plurality of first parts" described in the claims. Further, the plurality of connecting portions 37 correspond to the "plurality of second portions" described in the claims.

An example of a method for manufacturing the thermal print head C1 will be described with reference to FIGS. 19 to 25. 19, 22, and 24 are plan views showing one step of the manufacturing method of the thermal print head C1, and correspond to the enlarged plan view of the main part of FIG. 20, FIG. 21, FIG. 23, and FIG. 25 are cross-sectional views showing one step of the manufacturing method of the thermal print head C1, and correspond to the enlarged cross-sectional view of the main part of FIG. 20 shows a cross section along the XX-XX line of FIG. 19, FIG. 23 shows a cross section along the XXIII-XXIII line of FIG. 22, and FIG. 25 shows a cross section along the XXV-XXV line of FIG. 24. ..

The manufacturing method of the thermal print head C1 is different from the manufacturing methods of the thermal print heads A1 and B1 in the electrode layer forming step. The electrode layer forming step in the present embodiment includes a pre-coating step, a stamping step, a pre-baking step, a partial removal step, a trailing coating step, and a trailing coating step.

In the electrode layer forming step of the present embodiment, first, a preliminary coating step is performed. In the pre-coating step, the conductive paste 30B is applied to the second region 10B of the substrate 1 prepared in the substrate preparation step. The pre-coating step is performed by screen printing, and as shown in FIGS. 19 and 20, a solid pattern is formed on the entire surface of the second region 10B.

Next, a stamping process is performed. In the stamping step, as shown in FIG. 21, the imprint mold 91 having an uneven pattern is brought into contact with the conductive paste 30B applied in the prior coating step and pressed. Then, by releasing the pressure of the imprint mold 91, as shown in FIGS. 22 and 23, the thick portion 311 and the thin portion 312 are formed on the conductive paste 30B.

Next, a pre-baking step is performed. In the pre-baking step, the conductive paste 30B including the thick portion 311 and the thin portion 312 is fired. As a result, a fired body of the conductive paste 30B is formed. A step of drying the conductive paste 30B may be further added between the stamping step and the pre-baking step.

Next, a partial removal step is performed. In the partial removal step, as shown in FIGS. 24 and 25, the thin portion 312 is removed, leaving the thick portion 311 by etching, for example. In the present embodiment, the etching is performed on the entire surface, and the thick portion 311 also has a smaller dimension in the thickness direction z. A mask may be formed on the thick portion 311 so that the thick portion 311 does not become thin. The partial removing step is not limited to etching, and the thin portion 312 may be removed by, for example, blasting. As a result, as shown in FIGS. 24 and 25, a plurality of connecting portions 37 and a plurality of bonding portions 39 are formed. Therefore, a pattern of a plurality of connecting portions 37 and a plurality of bonding portions 39 (plurality of second portions) is formed by the partial removing step.

Next, a subsequent coating step is performed. In the subsequent coating step, the conductive paste 30A is applied to the first region 10A of the substrate 1. In the subsequent coating step, the conductive paste 30A is coated by screen printing in the pattern shown by the imaginary line in FIG. 24. The pattern shown by the imaginary line in FIG. 24 has substantially the same shape as the pattern shape of the plurality of common electrode band-shaped portions 34 and the connecting portion 35 and the plurality of individual electrode strip-shaped portions 38. Therefore, the patterning of the plurality of common electrode band-shaped portions 34 and the plurality of individual electrode strip-shaped portions 38 (plurality of first portions) is performed by the subsequent coating step.

Next, a subsequent firing step is performed. In the subsequent firing step, the conductive paste 30A is fired to form a plurality of common electrode strips 34 and connecting portions 35 (common electrodes 33), and a plurality of individual electrode strips 38. A step of drying the conductive paste 30A may be further added between the subsequent coating step and the subsequent firing step.

In the present embodiment, the subsequent coating step corresponds to the "first patterning step" described in the claims, and the subsequent firing step corresponds to the "first firing step" described in the claims. .. The pre-coating step corresponds to the "coating step" described in the claims, and the pre-firing step corresponds to the "second firing step" described in the claims. Further, the step of combining the pre-coating step, the stamping step, the pre-baking step and the partial removing step corresponds to the "second patterning step" described in the claims.

After that, the thermal print head C1 is manufactured by performing the resistor layer forming step, the protective layer forming step, and the assembling step in the same manner as in each of the manufacturing methods according to the first embodiment and the second embodiment.

The actions and effects of the method for manufacturing the thermal printhead C1 are as follows.

The method for manufacturing the thermal printhead C1 includes an electrode layer forming step including a first patterning step and a second patterning step, similarly to the manufacturing method for the thermal printheads A1 and B1. In the first patterning step, a plurality of patterns of the first part are formed by screen printing. In the present embodiment, for example, a plurality of common electrode band-shaped portions 34 and a plurality of individual electrode strip-shaped portions 38 are formed as the plurality of first portions. In the second patterning step, a plurality of patterns of the second part are formed by a method capable of patterning with a higher definition than screen printing. In the present embodiment, patterns of, for example, a plurality of connecting portions 37 and a plurality of bonding portions 39 are formed as the plurality of second portions. Therefore, the manufacturing method of the thermal print head C1 is similar to the manufacturing methods of the thermal print heads A1 and B1, and can pattern a plurality of second parts, which are difficult to pattern by screen printing, with a higher fineness than screen printing. Patterning is performed by the method. As a result, it is possible to form the electrode layer 3 in which the conduction path is appropriately configured.

In the method for manufacturing the thermal print head C1, a plurality of second parts are patterned by sequentially processing a pre-coating step, a stamping step, a pre-baking step, and a partial removing step. In the pre-coating step, the conductive paste 30B is applied to the second region 10B by screen printing to form a solid pattern on the entire surface of the second region 10B. In the stamping step, the solid pattern conductive paste 30B is pressed by the imprint mold 91 to form the thick portion 311 and the thin portion 312 on the conductive paste 30B. In the pre-baking step, the conductive paste 30B including the thick portion 311 and the thin portion 312 is fired to form a fired body of the conductive paste 30B. In the partial removal step, for example, the thick portion 311 is left by etching and the thin portion 312 is removed to form a plurality of patterns of the second portion. According to this configuration, a plurality of second parts can be patterned with higher definition than screen printing. Therefore, a plurality of second portions having a pattern shape finer than the plurality of first portions can be appropriately formed without causing a short circuit or disconnection.

In the manufacturing method according to the third embodiment, the electrode layer forming step is not limited to the above-mentioned method, and the electrode layer 3 may be formed by the following steps. For example, the preceding coating process and the succeeding coating process are collectively performed. At this time, the conductive paste 30A applied by the preceding coating step and the conductive paste 30B applied by the subsequent coating step are integrated. After that, a stamping step is performed to form a thick portion 311 and a thin portion 312 on the conductive paste 30B formed in the second region 10B. Then, the pre-baking step and the succeeding firing step are collectively performed, the conductive pastes 30A and 30B are fired at the same time, and the thin portion 312 is removed by the partial removing step. As a result, the electrode layer 3 may be formed. In this case, the first edge portion 37a of each connecting portion 37 is not formed under each individual electrode strip-shaped portion 38, but is integrally formed with each individual electrode strip-shaped portion 38. Further, for example, after the order of the preceding coating step and the succeeding coating step is changed to form a plurality of first portions (plurality of individual electrode strips 38 and the like), a plurality of second portions (plurality of connecting portions 37) are formed. Etc.) may be formed. That is, after applying the conductive paste 30A to the first region 10A by screen printing, the conductive paste 30A is fired. Then, a solid pattern conductive paste 30B is applied to the second region 10B by screen printing, and a stamping step is performed. Then, the conductive paste 30B after the stamping step is fired to perform a partial removal step. As a result, the electrode layer 3 may be formed. In this case, the first edge portion 37a of each connecting portion 37 is not formed below each individual electrode strip-shaped portion 38, but is formed on each individual electrode strip-shaped portion 38.

In the first to third embodiments, the case where the first covering portion 51 of the protective layer 5 includes the raised portion 511 is shown, but the present invention is not limited to this. For example, as shown in FIG. 26, the first covering portion 51 may not include the raised portion 511. FIG. 26 is an enlarged cross-sectional view of a main part showing a thermal print head according to such a modified example, and corresponds to the cross section shown in FIG. For example, the thermal printhead shown in FIG. 26 can be manufactured depending on the viscosity of the glass paste constituting the protective layer 5 used in the protective layer forming step and the firing conditions of the glass paste.

The method for manufacturing a thermal printhead and the thermal printhead according to the present disclosure are not limited to the above-described embodiments. The specific processing of each step of the thermal print head manufacturing method of the present disclosure and the specific configuration of each part of the thermal print head can be variously redesigned.

The method for manufacturing a thermal printhead and the thermal printhead according to the present disclosure include embodiments relating to the following appendices.
[Appendix 1]
The board preparation process to prepare the board and
A resistor layer forming step of forming a resistor layer including a plurality of heat generating portions arranged in the main scanning direction on the substrate,
An electrode layer forming step of forming an electrode layer for energizing the resistor layer, and
Includes
The electrode layer includes a plurality of first parts arranged with a first pitch width and a plurality of second parts arranged with a second pitch width smaller than the first pitch width.
The substrate includes a first region in which the plurality of first portions are formed in the thickness direction of the substrate, and a second region in which the plurality of second portions are formed in the thickness direction of the substrate. Including
The electrode layer forming step is
A first patterning step of forming the pattern of the plurality of first parts in the first region by screen printing, and
A second patterning step of forming the pattern of the plurality of second parts in the second region by a patterning method capable of patterning with a higher definition than the screen printing.
A method of manufacturing a thermal printhead, which comprises.
[Appendix 2]
The electrode layer further includes a plurality of bonding portions, each of which is connected to the drive IC via a wire.
Each of the plurality of second portions is connected to each of the plurality of bonding portions, and is arranged between the plurality of bonding portions and the plurality of first portions when viewed in the thickness direction. ,
The method for manufacturing a thermal printhead according to Appendix 1, wherein each of the plurality of first parts partially overlaps the resistor layer when viewed in the thickness direction.
[Appendix 3]
The manufacture of the thermal printhead according to Appendix 2, wherein the plurality of first parts and the plurality of second parts are respectively arranged in the main scanning direction and each has a strip shape extending along the sub-scanning direction. Method.
[Appendix 4]
The method for manufacturing a thermal print head according to Appendix 3, wherein the second pitch width is 10 μm or more and 100 μm or less.
[Appendix 5]
Each dimension of the plurality of second parts in the main scanning direction is 10 μm or more and 100 μm or less.
The method for manufacturing a thermal printhead according to Appendix 4, wherein the distance between the two second portions adjacent to each other in the main scanning direction is 10 μm or more and 100 μm or less.
[Appendix 6]
The electrode layer forming step further includes a first firing step.
In the first patterning step, the conductive paste is screen-printed on the first region in the shape of the pattern of the plurality of first parts.
The thermal print head according to any one of Supplementary note 2 to Supplementary note 5, wherein in the first firing step, the conductive paste printed in the first patterning step is fired to form the plurality of first parts. Manufacturing method.
[Appendix 7]
The electrode layer forming step further includes a second firing step.
In the second patterning step, the conductive paste is dispensed onto the second region in the form of the pattern of the plurality of second parts.
The method for manufacturing a thermal printhead according to Appendix 6, wherein the second firing step forms the plurality of second parts by firing the conductive paste applied in the second patterning step.
[Appendix 8]
In the first patterning step, a pattern of the plurality of bonding portions is further formed in the first region.
Each of the plurality of first parts is connected to each of the plurality of second parts.
Each of the plurality of second portions includes a first edge portion, a second edge portion, and an intermediate portion.
The intermediate portion connects the first end edge portion and the second end edge portion.
The first edge portion overlaps with each of the plurality of bonding portions when viewed in the thickness direction.
The method for manufacturing a thermal printhead according to Appendix 7, wherein the second edge portion overlaps with each of the plurality of first portions when viewed in the thickness direction.
[Appendix 9]
The second patterning step is
A coating step of applying a conductive paste to the second region by screen printing to form a solid pattern, and
A partial removal step of partially removing the solid pattern by laser processing and
Including
The method for manufacturing a thermal print head according to Appendix 6, wherein the solid pattern is formed into the shape of the plurality of second part patterns by the partial removal step.
[Appendix 10]
The second patterning step is
The method for manufacturing a thermal printhead according to Appendix 9, further comprising a second firing step of firing the solid pattern between the coating step and the partial removing step.
[Appendix 11]
The screen printing of the first patterning step and the screen printing of the coating step are performed collectively.
The method for manufacturing a thermal print head according to Appendix 10, wherein the firing in the first firing step and the firing in the second firing step are performed collectively.
[Appendix 12]
The second patterning step is
A coating step of applying a conductive paste to the second region by screen printing to form a solid pattern, and
A stamping step of forming a thick portion and a thin portion in the solid pattern by bringing an imprint mold having an uneven pattern into contact with the solid pattern and pressurizing the solid pattern.
A partial removal step of removing the thin portion while leaving the thick portion,
Including
The method for manufacturing a thermal print head according to Appendix 6, wherein the solid pattern is formed into the shape of the plurality of second part patterns by the stamping step and the partial removing step.
[Appendix 13]
The second patterning step is
The method for manufacturing a thermal printhead according to Appendix 12, further comprising a second firing step of firing the solid pattern between the stamping step and the partial removing step.
[Appendix 14]
The method for manufacturing a thermal print head according to any one of Appendix 12 or Appendix 13, wherein the thin portion is removed by etching or blasting in the partial removal step.
[Appendix 15]
The substrate preparation step is
A base material preparation step of preparing a base material having a main surface facing one side in the thickness direction, and
A glaze layer forming step of forming a glaze layer on the main surface is further included.
The glaze layer forming step is performed after the base material preparing step and before each step of the resistor layer forming step and the electrode layer forming step.
The method for manufacturing a thermal printhead according to any one of Appendix 1 to Appendix 14, wherein the resistor layer is formed on the glaze layer in the resistor layer forming step.
[Appendix 16]
The glaze layer includes a partial glaze that rises from the main surface in the thickness direction.
The method for manufacturing a thermal print head according to Appendix 15, wherein the plurality of heat generating portions are formed on the partial glaze.
[Appendix 17]
The method for manufacturing a thermal printhead according to any one of Supplementary note 1 to Supplementary note 16, further comprising a step of forming a protective layer for forming the protective layer that covers the resistor layer and the electrode layer.
[Appendix 18]
With the board
A resistor layer including a plurality of heat generating portions arranged in the main scanning direction and formed on the substrate,
An electrode layer for energizing the resistor layer and
Includes
The electrode layer includes a plurality of first parts, a plurality of second parts, and a plurality of bonding parts.
Each of the plurality of first parts has a band shape extending in the sub-scanning direction, and is arranged in the main scanning direction with the first pitch width.
Each of the plurality of second parts has a band shape extending in the sub-scanning direction, and is arranged in the main scanning direction with a second pitch width smaller than the first pitch width.
Each of the plurality of bonding portions is connected to the drive IC via a wire, and each of the plurality of bonding portions is connected to each of the plurality of second portions.
The plurality of first parts are patterned by screen printing.
A thermal print head, wherein the plurality of second parts are patterned by a method capable of patterning with a higher fineness than the screen printing.
[Appendix 19]
The thermal printhead according to Appendix 18, wherein each edge extending in the sub-scanning direction of the plurality of first parts and each edge extending in the sub-scanning direction of the plurality of second parts have different linearities.
[Appendix 20]
Each of the plurality of first parts is connected to each of the plurality of second parts.
Each of the plurality of second portions includes a first edge portion, a second edge portion, and an intermediate portion.
The intermediate portion connects the first end edge portion and the second end edge portion.
The first edge portion overlaps with each of the plurality of bonding portions when viewed in the thickness direction of the substrate.
The thermal print head according to any one of Appendix 18 or Appendix 19, wherein the second edge portion overlaps the plurality of first portions when viewed in the thickness direction.

A1, A2, B1, B2, B3, C1: Thermal printhead 1: Substrate 10A: First region 10B: Second region 11: Base material 11a: Main surface 12: Glaze layer 121: Partial glaze 122: Glass layer 3: Electrode layer 33: Common electrode 34: Common electrode band-shaped portion 341: Base portion 342: Extension portion 35: Connecting portion 36: Individual electrode 37: Connecting portion 37a: First end edge portion 37b: Second end edge portion 37c: Intermediate portion 371: Parallel part 371B: Fine wire part 372: Oblique part 38: Individual electrode strip-shaped part 381: Base part 382: Extension part 39: Bonding part 39A: First bonding part 39B: Second bonding part 30A, 30B, 30C: Conductive Sex paste 311: Thick part 312: Thin part 4: Resistor layer 41: Heat generation part 5: Protective layer 51: First coating part 511: Raised part 52: Second coating part 61: Wire 71: Drive IC
72: Encapsulating resin 73: Connector 74: Wiring board 75: Heat dissipation member 81: Platen roller 82: Printing medium 91: Imprint mold

Claims (20)

The board preparation process to prepare the board and
A resistor layer forming step of forming a resistor layer including a plurality of heat generating portions arranged in the main scanning direction on the substrate,
An electrode layer forming step of forming an electrode layer for energizing the resistor layer, and
Includes
The electrode layer includes a plurality of first parts arranged with a first pitch width and a plurality of second parts arranged with a second pitch width smaller than the first pitch width.
The substrate includes a first region in which the plurality of first portions are formed in the thickness direction of the substrate, and a second region in which the plurality of second portions are formed in the thickness direction of the substrate. Including
The electrode layer forming step is
A first patterning step of forming the pattern of the plurality of first parts in the first region by screen printing, and
A second patterning step of forming the pattern of the plurality of second parts in the second region by a patterning method capable of patterning with a higher definition than the screen printing.
including,
A method of manufacturing a thermal printhead, which is characterized by the fact that. The electrode layer further includes a plurality of bonding portions, each of which is connected to the drive IC via a wire.
Each of the plurality of second portions is connected to each of the plurality of bonding portions, and is arranged between the plurality of bonding portions and the plurality of first portions when viewed in the thickness direction. ,
Each of the plurality of first parts, when viewed in the thickness direction, partially overlaps the resistor layer.
The method for manufacturing a thermal print head according to claim 1. The plurality of first parts and the plurality of second parts are each arranged in the main scanning direction, and each has a strip shape extending along the sub-scanning direction.
The method for manufacturing a thermal print head according to claim 2. The second pitch width is 10 μm or more and 100 μm or less.
The method for manufacturing a thermal print head according to claim 3. Each dimension of the plurality of second parts in the main scanning direction is 10 μm or more and 100 μm or less.
The separation distance between the two second parts adjacent to each other in the main scanning direction is 10 μm or more and 100 μm or less.
The method for manufacturing a thermal print head according to claim 4. The electrode layer forming step further includes a first firing step.
In the first patterning step, the conductive paste is screen-printed on the first region in the shape of the pattern of the plurality of first parts.
In the first firing step, the plurality of first parts are formed by firing the conductive paste printed in the first patterning step.
The method for manufacturing a thermal print head according to any one of claims 2 to 5. The electrode layer forming step further includes a second firing step.
In the second patterning step, the conductive paste is dispensed onto the second region in the form of the pattern of the plurality of second parts.
In the second firing step, the plurality of second parts are formed by firing the conductive paste applied in the second patterning step.
The method for manufacturing a thermal print head according to claim 6. In the first patterning step, a pattern of the plurality of bonding portions is further formed in the first region.
Each of the plurality of first parts is connected to each of the plurality of second parts.
Each of the plurality of second portions includes a first edge portion, a second edge portion, and an intermediate portion.
The intermediate portion connects the first end edge portion and the second end edge portion.
The first edge portion overlaps with each of the plurality of bonding portions when viewed in the thickness direction.
The second edge portion overlaps with each of the plurality of first portions when viewed in the thickness direction.
The method for manufacturing a thermal print head according to claim 7. The second patterning step is
A coating step of applying a conductive paste to the second region by screen printing to form a solid pattern, and
A partial removal step of partially removing the solid pattern by laser processing and
Including
By the partial removal step, the solid pattern is formed into the shape of the plurality of second part patterns.
The method for manufacturing a thermal print head according to claim 6. The second patterning step is
A second firing step of firing the solid pattern is further included between the coating step and the partial removing step.
The method for manufacturing a thermal print head according to claim 9. The screen printing of the first patterning step and the screen printing of the coating step are performed collectively.
The firing in the first firing step and the firing in the second firing step are performed collectively.
The method for manufacturing a thermal print head according to claim 10. The second patterning step is
A coating step of applying a conductive paste to the second region by screen printing to form a solid pattern, and
A stamping step of forming a thick portion and a thin portion in the solid pattern by bringing an imprint mold having an uneven pattern into contact with the solid pattern and pressurizing the solid pattern.
A partial removal step of removing the thin portion while leaving the thick portion,
Including
By the stamping step and the partial removing step, the solid pattern is made into the shape of the pattern of the plurality of second parts.
The method for manufacturing a thermal print head according to claim 6. The second patterning step is
A second firing step of firing the solid pattern is further included between the stamping step and the partial removing step.
The method for manufacturing a thermal print head according to claim 12. In the partial removal step, the thin portion is removed by etching or blasting.
The method for manufacturing a thermal printhead according to claim 12 or 13. The substrate preparation step is
A base material preparation step of preparing a base material having a main surface facing one side in the thickness direction, and
A glaze layer forming step of forming a glaze layer on the main surface is further included.
The glaze layer forming step is performed after the base material preparing step and before each step of the resistor layer forming step and the electrode layer forming step.
In the resistor layer forming step, the resistor layer is formed on the glaze layer.
The method for manufacturing a thermal print head according to any one of claims 1 to 14. The glaze layer includes a partial glaze that rises from the main surface in the thickness direction.
The plurality of heat generating portions are formed on the partial glaze.
The method for manufacturing a thermal print head according to claim 15. A protective layer forming step of forming a protective layer covering the resistor layer and the electrode layer is further included.
The method for manufacturing a thermal print head according to any one of claims 1 to 16. With the board
A resistor layer including a plurality of heat generating portions arranged in the main scanning direction and formed on the substrate,
An electrode layer for energizing the resistor layer and
Includes
The electrode layer includes a plurality of first parts, a plurality of second parts, and a plurality of bonding parts.
Each of the plurality of first parts has a band shape extending in the sub-scanning direction, and is arranged in the main scanning direction with the first pitch width.
Each of the plurality of second parts has a band shape extending in the sub-scanning direction, and is arranged in the main scanning direction with a second pitch width smaller than the first pitch width.
Each of the plurality of bonding portions is connected to the drive IC via a wire, and each of the plurality of bonding portions is connected to each of the plurality of second portions.
The plurality of first parts are patterned by screen printing.
The plurality of second parts are patterned by a method capable of patterning with a higher definition than the screen printing.
A thermal print head that features that. The linearity of each edge extending in the sub-scanning direction of the plurality of first parts and each edge extending in the sub-scanning direction of the plurality of second parts are different.
The thermal print head according to claim 18. Each of the plurality of first parts is connected to each of the plurality of second parts.
Each of the plurality of second portions includes a first edge portion, a second edge portion, and an intermediate portion.
The intermediate portion connects the first end edge portion and the second end edge portion.
The first edge portion overlaps with each of the plurality of bonding portions when viewed in the thickness direction of the substrate.
The second edge portion overlaps the plurality of first portions when viewed in the thickness direction.
The thermal printhead according to claim 18 or 19.

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