Thermal head and recording device

Abstract

A thermal head has a plurality of heat generating parts (5), a first conductor layer (15), and a second conductor layer (17). The plurality of heat generating parts (5) are arranged in a first direction (D1). The second conductor layer (17) has a lower electrical resistivity than the first conductor layer (15). The first conductor layer (15) has a plurality of leads (19) and specific wiring (21). The plurality of leads (19) extend from the plurality of heat generating parts (5) in a second direction (D2) intersecting the first direction (D1). The specific wiring (21) connects the plurality of leads (19) to each other. The second conductor layer (17) has a main part (23) that covers at least a part of the specific wiring (21). The specific wiring (21) overlaps a part of the length of the main part (23) in the second direction (D2). In a region overlapping the main part (23), the position in the second direction (D2) of at least one of the lateral edge parts on both sides in the second direction (D2) of the specific wiring (21) changes according to the position thereof in the first direction (D1).

Description

Thermal head and recording device

[0001] The present disclosure relates to a thermal head and a recording device having the thermal head.

[0002] A thermal head is known that heats thermal paper to print on the thermal paper or heats an ink ribbon to print on a recording medium (e.g., paper) (see, for example, Patent Document 1 below). The thermal head has multiple heat generating elements that are used for the heating described above. The multiple heat generating elements are arranged in a direction perpendicular to the direction of relative movement between the head and the recording medium.

[0003] The thermal head has a common electrode and a plurality of individual electrodes for applying a voltage to the plurality of heat generating elements. The common electrode includes a portion extending along the arrangement of the plurality of heat generating elements and is connected to the plurality of heat generating elements. The plurality of individual electrodes are individually connected to the plurality of heat generating elements. By individually controlling the potentials applied to the plurality of individual electrodes, the temperatures of the plurality of heat generating elements are individually controlled, and ultimately, any desired image is formed on the recording medium. The thermal head of Patent Document 1 uses both a gold (Au) conductor pattern and a silver (Ag) conductor pattern.

[0004] Japanese Patent Application Laid-Open No. 2022-78589

[0005] A thermal head according to one aspect of the present disclosure has a plurality of heat generating portions, a first conductor layer, and a second conductor layer. The plurality of heat generating portions are arranged in a first direction. The second conductor layer has a lower electrical resistivity than the first conductor layer. The first conductor layer has a plurality of leads and a specific wiring. The leads extend from the plurality of heat generating portions in a second direction intersecting the first direction. The specific wiring connects the plurality of leads to each other. The second conductor layer has a main portion covering at least a portion of the specific wiring. The specific wiring overlaps a portion of the length of the main portion in the second direction. At least one of the side edge portions on both sides of the specific wiring in the second direction changes position in the second direction depending on its position in the first direction in the region overlapping the main portion.

[0006] A recording device according to one aspect of the present disclosure includes the thermal head and a moving unit that moves the thermal head and the recording medium relative to each other.

[0007] 1 is a schematic exploded perspective view of a thermal head according to an embodiment. A plan view showing an extracted portion of the thermal head of FIG. 1. A cross-sectional view taken along line III-III in FIG. 2. A plan view showing a first example of the configuration in region IV of FIG. 2. A plan view showing a second example of the configuration in region IV of FIG. 2. A schematic view showing first to third patterns of common electrodes included in the thermal head of FIG. 1. A schematic view showing fourth to sixth patterns of common electrodes. A schematic view showing seventh to ninth patterns of common electrodes. A schematic view showing tenth to twelfth patterns of common electrodes. A schematic view showing thirteenth and fourteenth patterns of common electrodes. A schematic view showing fifteenth and sixteenth patterns of common electrodes. A schematic view showing seventeenth and eighteenth patterns of common electrodes. A schematic view showing nineteenth and twentieth patterns of common electrodes. A cross-sectional view of a printer according to an embodiment.

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The drawings used in the following description are schematic. Therefore, for example, the dimensional ratios in the drawings do not necessarily correspond to the actual ones. Furthermore, the dimensional ratios may not match between drawings. Certain shapes and / or dimensions may be exaggerated, and details may be omitted. However, the above does not deny that the actual shapes and / or dimensions may be as shown in the drawings, or that features of shapes and / or dimensions may be extracted from the drawings.

[0009] For convenience, the drawings may be illustrated with a Cartesian coordinate system D1D2D3, and terms such as D1 direction, D2 direction, and D3 direction may be used. The D1 direction is an example of a first direction, and the D2 direction is an example of a second direction. As will be understood from the description below, the term D1 direction may be replaced with the term "direction perpendicular to the longitudinal direction of the head, the arrangement direction of multiple heat generating elements, and / or the direction of relative movement between the head and the recording medium." The term D2 direction may be replaced with the term "direction perpendicular to the lateral direction of the head, the direction perpendicular to the arrangement direction, and / or the direction of relative movement." The term D3 direction may be replaced with the term "direction normal to the head body." The thermal head and recording device according to the embodiment may be used in any orientation. However, for convenience, terms may be used assuming that the +D3 side is upward.

[0010] 1 is a schematic exploded perspective view of a thermal head 1 (hereinafter, simply referred to as "head 1") according to an embodiment. The head 1 has a head main body 3 that is directly responsible for recording (e.g., printing) on ​​a recording medium (e.g., paper). The head main body 3 may be regarded as an example of a thermal head.

[0011] The head main body 3 has a plurality of heat generating parts 5 arranged in the direction D1. With the thermal paper sliding in the direction D2 relative to the plurality of heat generating parts 5, the temperatures of the plurality of heat generating parts 5 are individually controlled to form an arbitrary image on the thermal paper. Alternatively, with the ink ribbon sliding in the direction D2 relative to the plurality of heat generating parts 5, the temperatures of the plurality of heat generating parts 5 are individually controlled to form an arbitrary image on a recording medium (e.g., paper) moving with the ink ribbon over the plurality of heat generating parts 5.

[0012] As will be understood from the description below, the plurality of heat generating portions 5 may be covered with a protective film or the like so as not to be exposed to the outside. In other words, the plurality of heat generating portions 5 may be prevented from directly sliding against the thermal paper or ink ribbon. However, for convenience, the plurality of heat generating portions 5 may be expressed as if they were exposed to the outside, as described above. Also, for convenience, the plurality of heat generating portions 5 are shown in solid lines in FIG. 1.

[0013] 2 is a plan view of the head main body 3. However, in FIG. 2, some of the components are selectively shown.

[0014] The head main body 3 has a substrate 7, and also has a resistor 9, a common electrode 11, and a plurality of individual electrodes 13 located on the surface of the substrate 7. Portions of the resistor 9 to which a voltage is applied by the common electrode 11 and the plurality of individual electrodes 13 constitute a plurality of heat generating portions 5.

[0015] As will be understood from the description below, the resistor 9, the common electrode 11, and the individual electrodes 13 do not have to be directly superimposed on the surface of the substrate 7. However, for the sake of convenience, the description of the embodiments may be given in a manner that ignores the existence of layers interposed between these components and the substrate 7.

[0016] In the illustrated example, the resistor 9 extends in the direction D1. The common electrode 11 has a comb-tooth portion 11a. The comb-tooth portion 11a has a main wiring portion 11b extending in parallel with the resistor 9 and a plurality of extension portions 11c extending from the main wiring portion 11b toward the resistor 9 and overlapping the resistor 9. The plurality of individual electrodes 13 overlap the resistor 9 between the plurality of extension portions 11c. The portions of the resistor 9 between adjacent extension portions 11c and individual electrodes 13 form heat-generating portions 5.

[0017] For example, a constant potential (e.g., a reference potential) is applied to the common electrode 11. Drive signals (e.g., pulses) are individually applied to the individual electrodes 13. By controlling the potential and the like of the drive signals for each individual electrode 13, the temperatures of the heat generating portions 5 are individually controlled.

[0018] Fig. 4 is an enlarged view of region IV in Fig. 2. For convenience, the surface (i.e., the surface other than the cross section) of a first conductor layer 15 described later is hatched with polka dots. Fig. 5 is a view showing an example of the configuration of region IV that is different from that shown in Fig. 4.

[0019] The comb-tooth portion 11a is composed of a first conductor layer 15 and a second conductor layer 17 covering the first conductor layer 15. The electrical resistivity of the material of the second conductor layer 17 is lower than the electrical resistivity of the material of the first conductor layer 15.

[0020] Specifically, the first conductor layer 15 has a plurality of leads 19 extending in the D2 direction from a plurality of heat generating portions 5, and specific wiring 21 (a plurality of bridges 21a) connecting the plurality of leads 19. The second conductor layer 17 has a main portion 23 covering at least a portion of the specific wiring 21 (in the illustrated example, the entire specific wiring 21 and a portion of the plurality of leads 19 on the specific wiring 21 side).

[0021] The main wiring portion 11b is formed by the main portion 23 and the portion of the first conductor layer 15 that is covered by the main portion 23. The extension portion 11c is formed by the portion of the first conductor layer 15 (more specifically, the lead 19) that is not covered by the main portion 23.

[0022] In such a configuration, for example, the electrical resistivity of the main wiring portion 11b can be reduced compared to an embodiment in which the main wiring portion 11b is formed only by the first conductor layer 15. Furthermore, for example, by using a material for the second conductor layer 17 that is cheaper than the material for the first conductor layer 15, the cost of the head body 3 can be reduced.

[0023] On the other hand, for example, by using a material that is unlikely to diffuse into the resistor 9 as the first conductor layer 15, it is possible to reduce the likelihood of a deterioration in the characteristics of the plurality of heat generating portions 5. In addition, for example, by overlapping the first conductor layer 15 and the second conductor layer 17, it is possible to improve the reliability of the connection therebetween.

[0024] Here, the specific wiring 21 overlaps a portion of the length (width W1) of the main portion 23 in the D2 direction. The specific wiring 21 extends in the D1 direction while changing its position in the D2 direction. From another perspective, at least one of the side edge portions 21b on both sides of the specific wiring 21 in the D2 direction (both in the illustrated example) changes its position in the D2 direction depending on its position in the D1 direction in the region overlapping the main portion 23.

[0025] In this case, for example, the area where the specific wiring 21 and the main portion 23 overlap is reduced compared to an embodiment in which the specific wiring 21 has the same shape and dimensions as the main portion 23. This reduces, for example, the likelihood of interdiffusion between the material of the first conductor layer 15 and the material of the second conductor layer 17. Consequently, the likelihood that the electrical resistance of the main portion 23 will increase due to diffusion of the material of the first conductor layer 15 is reduced.

[0026] Furthermore, by exerting the effect of allowing current to flow through the main portion 23 with low electrical resistance, the difference in current loss between the ends and center of the main wiring portion 11b is reduced. As a result, the likelihood of unintended temperature variations occurring in the multiple heat-generating portions 5 is reduced. Ultimately, the likelihood of unintended density variations occurring on the recording medium is reduced. In other words, image quality is improved.

[0027] On the other hand, because the position of the lateral edge 21b of the specific wiring 21 changes in the D2 direction, the range of positions at which the specific wiring 21 and the main portion 23 are joined is wider in the D2 direction than in a configuration in which the specific wiring 21 extends linearly in the D1 direction. For example, when imaginary lines (not shown) parallel to the D1 direction passing through the position of the specific wiring 21 furthest on the -D2 side, and imaginary lines (not shown) parallel to the D1 direction passing through the position of the specific wiring 21 furthest on the +D2 side, are assumed, the area sandwiched between these two imaginary lines is wider. As a result, for example, the reliability of the joint between the two is improved.

[0028] The above is an overview of the head 1 according to the embodiment. The head 1 will be described below in the following order: 1. Overall configuration of the head (FIG. 1) 2. Head main body (FIGS. 2 to 5) 2.1. General 2.2. Substrate, resistor, common electrode, and individual electrode 2.3. Other components 3. First conductor layer and second conductor layer 4. Specific wiring and surrounding area 4.1. Overview of basic pattern (FIGS. 4 and 5) 4.2. Basic pattern variations (FIGS. 6 and 7) 4.3. Protrusions (FIGS. 8 and 9) 4.4. Mesh pattern (FIG. 10) 4.5. Corners of outer edge (FIG. 11) 4.6. Details of basic pattern (FIG. 12) 4.7. Branching of extensions (FIG. 13) 4.8. Dimensions related to overlap between specific wiring and main part 5. Method for manufacturing the head main body 6. Printer (FIG. 14) 7. Summary of the embodiment

[0029] (1. Overall Configuration of Head) The head 1 may have various configurations, excluding the configuration of the specific wiring 21 and its surrounding parts, and may have, for example, a known configuration. Below, the overall configuration of the head 1 will be briefly described using the configuration of the head 1 shown in the drawings as an example.

[0030] 1, the head 1 may include the following components in addition to the head main body 3. Connector 25: For example, electrically connects the head main body 3 to external devices (for example, a power supply unit 107 and a control unit 109 shown in FIG. 14, which will be described later). Heat sink 27: For example, absorbs and releases unnecessary heat from the head main body 3. Adhesive member 29: For example, bonds the underside of the head main body 3 to the heat sink 27.

[0031] Any appropriate number of connectors 25 may be provided for the head body 3. The head body 3 illustrated in Fig. 2 illustrates a wiring pattern to which three connectors 25 can be connected, but for convenience, Fig. 1 illustrates only one connector 25. Instead of the connectors 25, FPCs (Flexible Printed Circuits) may be connected to the head body 3.

[0032] (2. Head Main Body) In this section, the head main body 3 will be described except for the specific configuration related to the specific wiring 21 and its surrounding area.

[0033] (2.1. General) The head main body 3 may have various configurations, excluding the configuration related to the specific wiring 21 and its surrounding parts, and may have, for example, a known configuration. The configuration shown in Figures 1 and 2 is merely an example.

[0034] 1 and 2, the heat generating portions 5 are located on the upper surface 7a of the substrate 7. Unlike the illustrated example, the heat generating portions 5 may be located on a side surface of the substrate 7 (e.g., the surface facing the +D2 side), or on an inclined surface formed by chamfering the corner between the upper surface 7a and the side surface. Similarly, all or part of the comb tooth portions 11a of the common electrode 11 and the portions of the individual electrodes 13 connected to the heat generating portions 5 may be located on a side surface or an inclined surface, rather than on the upper surface 7a. In the comb tooth portions 11a, at least a portion of the main wiring portion 11b opposite to the extension portion 11c and at least a portion of the extension portion 11c opposite to the main wiring portion 11b may be located on different surfaces.

[0035] 1 and 2, as described above, the plurality of extension portions 11c and the plurality of individual electrodes 13 are alternately arranged in the direction D1. Unlike the illustrated example, the plurality of extension portions 11c and the plurality of individual electrodes 13 may be arranged such that their tips face each other in the direction D2 with a gap therebetween. From another perspective, the plurality of extension portions 11c and the plurality of individual electrodes 13 (their tips) may be arranged at the same position as each other in the direction D1. Then, a portion of the resistor 9 located between the tip of the extension portion 11c and the tip of the individual electrode 13 may function as the heat generating portion 5. The common electrode 11 and the individual electrode 13 may overlap the resistor 9 from below (in the illustrated example) or from above.

[0036] Furthermore, for example, the head body 3 may have, unlike the illustrated example, multiple auxiliary heating elements that supplementarily heat the recording medium before it reaches the multiple heating elements 5. The application of voltage to such auxiliary heating elements may be achieved, for example, by multiple individual electrodes 13, multiple common electrodes (separate from the common electrode 11) located on the -D2 side of the resistor 9, and a resistor having a portion located therebetween. In the above embodiment, the individual electrodes 13 may have, in addition to the shape of the illustrated example, a portion that folds back from that shape toward the -D2 side and reaches the auxiliary heating elements. Alternatively, a single auxiliary heating element extending in the D1 direction may be provided.

[0037] Furthermore, for example, the head main body 3 may have any size. From another perspective, the size of the recording medium may be any size. For example, paper as the recording medium may be small like a receipt, may be a size commonly used in offices, or may be large like a poster. As can be understood from the above description, the dimensions of each component (such as the substrate 7, resistor 9, common electrode 11, and individual electrodes 13) constituting the head main body 3 may be any size. Furthermore, in the illustrated example, the arrangement direction of the multiple heat generating elements 5 coincides with the longitudinal direction of the head main body 3, but the two directions may be perpendicular to each other.

[0038] (2.2. Substrate, Resistor, Common Electrode, and Individual Electrode) As can be understood from the above, various configurations may be used for the substrate 7, resistor 9, common electrode 11, and individual electrode 13. The following mainly describes the configuration exemplified in FIG.

[0039] The substrate 7 is formed of, for example, an electrically insulating material such as alumina ceramics, or a semiconductor material such as single crystal silicon, etc. The substrate 7 is generally plate-shaped with its thickness direction in the D3 direction, and its shape in plan view is rectangular with long sides extending in the D1 direction and short sides extending in the D2 direction.

[0040] The resistor 9 is made of a material with a relatively high electrical resistivity, and generates Joule heat when a voltage is applied to it. Examples of the material for the resistor 9 include TaN-based, TaSiO-based, TaSiNO-based, TiSiO-based, TiSiCO-based, NbSiO-based, and RuO-based.２ Examples of such resistors include those of the type described above. The resistor 9 extends, for example, near one of the two long sides of the substrate 7 and parallel to the long side. The width of the resistor 9 is, for example, constant. The shape of the cross section (D2-D3 cross section) of the resistor 9 is arbitrary. For example, in the cross section of the resistor 9, the upper surface of the resistor 9 may be a curved shape (for example, an arc shape) that bulges outward, or a linear shape.

[0041] For example, the entire common electrode 11 is located on the upper surface 7a of the substrate 7. The common electrode 11 also has, for example, the comb-tooth portion 11a described above and a sub-wiring portion 11d for connecting the comb-tooth portion 11a to the connector 25. Unlike the example shown in the figure, for example, the common electrode 11 may extend to the side surface on the +D2 side and the lower surface (or inside) of the substrate 7 and be connected to the connector 25. In this case, the sub-wiring portion 11d is not necessary.

[0042] The main wiring portion 11b of the comb tooth portion 11a extends parallel to the direction D1 (linearly) with a constant width. Unlike the illustrated example, for example, the width of the main wiring portion 11b may vary depending on the position in the direction D1. Furthermore, as can be understood from the above description of the common electrode 11, the main wiring portion 11b may extend to other surfaces of the substrate 7. The description of the planar shape of the main wiring portion 11b may be applied to the planar shape of the main portion 23 of the second conductor layer 17 unless otherwise specified or unless a contradiction occurs.

[0043] The multiple extensions 11c of the comb tooth portion 11a have, for example, the same configuration and are arranged at a constant pitch in the D1 direction. Each extension 11c extends, for example, parallel (linearly) in the D2 direction from the main wiring portion 11b toward the resistor 9 and traverses the entire width of the resistor 9 in a plan view. For example, the portion of the extension 11c traversing the resistor 9 may be narrower in width than the portion on the main wiring portion 11b side (see FIGS. 4 and 5), or the width may be constant over the entire length. The description of the planar shape of the extension 11c may be applied to the planar shape of the lead 19 of the first conductor layer 15 unless otherwise specified or unless a contradiction arises.

[0044] The individual electrodes 13 extend, for example, from the side opposite the main wiring portion 11b of the common electrode 11 with respect to the resistor 9 toward the resistor 9, and traverse the entire width of the resistor 9. The individual electrodes 13 have, for example, the same configuration as each other in the portions that traverse the resistor 9 (the ends on the resistor 9 side), and these traversing portions are arranged at a constant pitch in the D1 direction. The portions of the individual electrodes 13 opposite the resistor 9 extend toward a driving IC (Integrated Circuit) described below. The shape of these portions is arbitrary.

[0045] As described above, at least the portion of the main wiring portion 11b opposite the extension portion 11c and at least the portion of the extension portion 11c opposite the main wiring portion 11b may be located on different surfaces of the substrate 7. Furthermore, as described above, the common electrode 11 may extend to the lower surface of the substrate 7. As can be understood from this example, the second direction intersecting the arrangement direction (first direction) of the multiple heat generating portions 5 may be broadly interpreted. That is, the second direction does not have to be a linear direction, but may be a circumferential direction extending from the upper surface 7a toward the +D2 side, toward the lower surface, and toward the -D2 side. Furthermore, the main wiring portion 11b (or the main portion 23) may have a shape whose length in the second direction cannot be considered as its width (in other words, it may have a shape that cannot be considered as extending in the first direction). However, for convenience, in describing the embodiments, expressions based on the illustrated example may be used without special mention.

[0046] 2, the head main body 3 may have the following components in addition to the components described above. One or more (three in the illustrated example) driving ICs 31: For example, generate driving signals to be input to the plurality of individual electrodes 13. Note that the driving IC 31 may not be considered a component of the head main body 3. A plurality of connection wirings 33: For example, connect the driving IC 31 to the connector 25.

[0047] The driving IC 31 is mounted on the substrate 7, and generates driving signals in response to signals input from the connector 25 via connection wiring 33, and inputs the driving signals to the plurality of individual electrodes 13. The plurality of connection wirings 33 are configured by a conductor layer located on the surface of the substrate 7. The shape, etc., of the plurality of connection wirings 33 is arbitrary. Although not particularly shown, wiring (conductor layer) connecting the driving ICs 31 to each other may be provided on the surface of the substrate 7.

[0048] FIG. 3 is a cross-sectional view taken along line III-III in FIG.

[0049] As shown in this figure, the head body 3 may have the following components in addition to the substrate 7, first conductor layer 15, and second conductor layer 17 already described. Heat generating portion glaze 35a: For example, contributes to heat storage below the heat generating portion 5. Wiring portion glaze 35b: For example, forms a surface on the substrate 7 (below the wiring) that is less irregular than the surface of the substrate 7. Protective film 37: For example, insulates the electrodes, wiring, and resistors. Durable film 39: For example, improves the durability of the head body 3 against sliding of the recording medium. Protective resin 41: For example, improves the printability of the hard coats (43 and 45) described below. IC hard coat 43: For example, protects the drive IC 31. Connector hard coat 45: For example, reinforces the connection of the connector 25 to the head body 3.

[0050] The heat generating portion glaze 35a is formed, for example, in a curved (e.g., arc-shaped) or linear cross section with the upper surface bulging outward. The cross section has a constant shape and dimensions and extends in the direction D1. The resistor 9-side portion of the extension 11c, the resistor 9-side portion of the individual electrode 13, and the resistor 9 overlap the upper surface of the heat generating portion glaze 35a.

[0051] The wiring portion glaze 35b is located at a certain distance from the heat generating portion glaze 35a toward the -D2 side and spreads over almost the entire upper surface 7a of the substrate 7. The -D2 side portions of the sub wiring portions 11d, the -D2 side portions of the individual electrodes 13, and the connection wiring 33 overlap the upper surface of the wiring portion glaze 35b.

[0052] In positions where the heat-generating portion glaze 35a and the wiring portion glaze 35b are not disposed, the first conductor layer 15 and the second conductor layer 17 directly overlap, for example, the upper surface 7a of the substrate 7. Examples of such portions include the specific wiring 21 (for example, the entirety thereof), the main portion 23 (for example, the entirety thereof), the middle portion of the extension portion 11c, the middle portion of the sub-wiring portion 11d, and the middle portion of the individual electrode 13.

[0053] The heat generating portion glaze 35a and the wiring portion glaze 35b are made of glass, and these may be collectively regarded as the glaze layer 35. Unlike the illustrated example, the glaze layer 35 may extend over the entire upper surface 7a of the substrate 7.

[0054] The protective film 37 is made of, for example, glass and extends over almost the entire upper surface 7 a of the substrate 7, excluding, for example, the region where the driving IC 31 is disposed and the region where the connector 25 is disposed. Consequently, the common electrode 11, the plurality of individual electrodes 13, and the connection wiring 33 are covered by the protective film 37 (i.e., almost entirely) except for the portions connected to the driving IC 31 or the connector 25.

[0055] Durable film 39 is made of, for example, SiN, SiO, SiON, SiC, SiCN, or diamond-like carbon and covers protective film 37. Durable film 39 covers, for example, the entire arrangement area of ​​heat generating portion glaze 35a and its peripheral area in a planar perspective view.

[0056] The protective resin 41, IC hard coat 43, and connector hard coat 45 are each made of an appropriate type of resin. The IC hard coat 43 covers (seals) the driver IC 31. The connector hard coat 45 covers the connector 25 except for the terminal portion for connecting the connector 25 to the outside. The protective resin 41 covers almost the entire wiring portion glaze 35b from above the durable film 39, while avoiding the area where the hard coat is disposed.

[0057] The above-described stacked structure is merely an example and may be modified as appropriate. For example, a base layer may be provided on top of the glaze layer 35 to cover the entire upper surface 7a of the substrate 7. In other words, a base layer may be provided between the glaze layer 35 and the conductor layer (first conductor layer 15 or second conductor layer 17). This base layer may contribute, for example, to reducing the likelihood that etching of the conductor layer will affect layers below the conductor layer. Furthermore, for example, a conductor layer other than the first conductor layer 15 and the second conductor layer 17 may be provided.

[0058] (3. First Conductive Layer and Second Conductive Layer) The material of the first conductor layer 15 and the material of the second conductor layer 17 may be any material as long as the electrical resistivity of the latter is lower than that of the former. There are an infinite number of combinations of such materials.

[0059] For example, the material of the first conductor layer 15 may be gold (Au) or an Au alloy, or aluminum (Al) or an Al alloy, and the material of the second conductor layer 17 may be silver (Ag) or an Ag alloy, or Cu or a Cu alloy. The former example and the latter example may be combined in any manner, and for example, a combination of Au and Ag may be used.

[0060] The Au alloy contains, for example, 50 mass % or more or 80 mass % or more of Au. Similarly, other alloys contain Al, Ag, or Cu in the above-mentioned mass %.

[0061] The specific value of the electrical resistivity and the specific degree of difference between the electrical resistivity of the first conductor layer 15 and the second conductor layer 17 are also arbitrary. For example, the electrical resistivity of the first conductor layer 15 is 2.0×10 －８ Ωm or more 10.0 x 10 －８ The electrical resistivity of the second conductor layer 17 may be 1.0×10 －８ Ωm or more 6.0 x 10 －８ The electrical resistivity of the second conductor layer 17 may be Ωm or less (however, smaller than the electrical resistivity of the first conductor layer 15). The ratio of the electrical resistivity of the second conductor layer 17 to the electrical resistivity of the first conductor layer 15 (second conductor layer 17 / first conductor layer 15) may be, for example, 0.3 or more and 0.7 or less.

[0062] The thicknesses of the first conductor layer 15 and the second conductor layer 17 may be any thickness, and the difference between the two may also be any thickness. For example, the thickness of the second conductor layer 17 may be greater than the thickness of the first conductor layer 15. This improves the effect of reducing electrical resistance by the second conductor layer 17. The thickness of the first conductor layer 15 may be, for example, 0.3 μm or more and 1.5 μm or less. The thickness of the second conductor layer 17 may be, for example, 5 μm or more and 25 μm or less. The thickness of the second conductor layer 17 may be, for example, 5 times or more and 30 times or less the thickness of the first conductor layer 15.

[0063] The first conductor layer 15 may constitute, for example, the individual electrodes 13 and the connection wiring 33 in addition to the leads 19 and the specific wiring 21. Note that the portion of the individual electrodes 13 on the side of the driving IC 31 and some or all of the connection wiring 33 may be constituted by the second conductor layer 17 or another conductor layer.

[0064] The second conductor layer 17 may constitute, for example, a sub-wiring portion 11d in addition to the main portion 23. Note that a part or all of the sub-wiring portion 11d may be constituted by the first conductor layer 15 or another conductor layer.

[0065] (4. Specific Wiring and Its Surrounding Portions) (4.1. Overview of Basic Pattern) As already described, the specific wiring 21 (FIGS. 4 and 5) connects the plurality of leads 19. From another perspective, the specific wiring 21 has bridges 21 a that span between adjacent ones of the plurality of leads 19.

[0066] The portion of the lead 19 between adjacent bridges 21a may or may not be considered as part of the specific wiring 21. In the description of the embodiments, for convenience, the former or latter interpretation may be used without special mention. Furthermore, the term "side edge 21b" may refer to the side edge of the entire specific wiring 21 or to the side edge of each bridge 21a.

[0067] In the examples of Figures 4 and 5, the specific wiring 21 extends in the D1 direction while changing its position in the D2 direction. From another perspective, the specific wiring 21 extends in the D1 direction while moving back and forth in the D2 direction. In the description of the embodiment, for convenience, such a pattern may be referred to as a basic pattern. Patterns different from the basic pattern (see Figure 10) will be described later. However, as will also be described later, the pattern in Figure 10 can also be considered a type of basic pattern.

[0068] 4 and 5 , the side edge portions 21b on both sides of the specific wiring 21 change their positions in the D2 direction depending on their positions in the D1 direction in the region overlapping the main portion 23 of the second conductor layer 17. Unlike the illustrated example, only one of the side edge portions 21b may change its position in the D2 direction in the region overlapping the main portion 23. Examples of such a configuration, although not particularly illustrated, include a configuration in which only one of the two side edge portions 21b changes its position in the D2 direction, while the other does not change its position in the D2 direction, and a configuration in which only one of the two side edge portions 21b overlaps the main portion 23 and changes its position in the D2 direction, while the other does not overlap the main portion 23.

[0069] 4 and 5, the entire specific wiring 21 overlaps the main portion 23. However, as mentioned above, only a portion of the specific wiring 21 may overlap the main portion 23 (see also FIG. 13 described later). An example of such an embodiment will be given below, assuming that the edge on the −D2 side of the main portion 23 is a straight line parallel to the D1 direction.

[0070] 4, the edge on the -D2 side of the main portion 23 may intersect with the lateral edge 21b on the -D2 side, may be located between the lateral edge 21b on the -D2 side and the lateral edge 21b on the +D2 side, or may intersect with the lateral edge 21b on the +D2 side. As will be understood from FIG. 13, which will be described later, depending on the specific aspect of the specific wiring 21, the edge on the -D2 side of the main portion 23 may intersect with both the lateral edge 21b on the -D2 side and the lateral edge 21b on the +D2 side.

[0071] 5, the edge on the −D2 side of the main portion 23 may intersect with the lateral edge 21b on the −D2 side or with the lateral edge 21b on the +D2 side. Depending on the specific aspect of the specific wiring 21, the edge on the −D2 side of the main portion 23 may be located between the lateral edge 21b on the −D2 side and the lateral edge 21b on the +D2 side, or may intersect with both.

[0072] In the drawings illustrating the specific wiring 21, for convenience, any of the above-mentioned aspects may be taken as an example. However, in each drawing, the width of the specific wiring 21 may be different from that shown in the drawings. Furthermore, for convenience, the description may be given on the assumption that the entire specific wiring 21 overlaps with the main portion 23, as in the examples of FIGS. 4 and 5, unless otherwise specified.

[0073] The width of the specific wiring 21 (the length in the direction perpendicular to the center line) may be constant or may vary. Furthermore, the width of the specific wiring 21 may be smaller than, equal to, or larger than the width of the lead 19. In the drawings illustrating the specific wiring 21, for convenience, one of the above embodiments is used as an example, but in each drawing, the width of the specific wiring 21 may be different from that shown in the drawing.

[0074] Specific examples of the planar shape of the specific wiring 21 and its surrounding area will be described below.

[0075] (4.2. Variations of Basic Pattern) There are various possible specific aspects of the basic pattern of the specific wiring 21. Figures 6 and 7 are plan views schematically showing specific examples of the basic pattern.

[0076] In the example shown in the upper part of FIG. 6 , the bridge 21a is inclined with respect to the D1 direction. From another perspective, the positions of both ends of the bridge 21a in the D2 direction are different from each other. The inclination direction (whether the end on the +D1 side is located on the -D2 side or the +D2 side with respect to the end on the -D1 side) and inclination angle of the multiple bridges 21a are, for example, the same as each other. Unlike the example shown in the figure, the inclination direction and / or inclination angle may change for every predetermined number of bridges 21a (one or more), or the inclination direction and / or inclination angle may change randomly. The specific value of the inclination angle is arbitrary, and may be, for example, 45° or more (as in the example of FIG. 4 ) or less than 45°.

[0077] In the example shown in the middle of FIG. 6 , the bridge 21 a extends while bending. The specific bending manner (e.g., direction and angle) of the multiple bridges 21 a is, for example, the same as each other. In the illustrated example, the bridge 21 a has one bend where two straight portions intersect, moving toward the +D2 side (the opposite side from the resistor 9) and then returning. Unlike the illustrated example, the bridge 21 a may bend toward the −D2 side and then return, extend in a curved shape as a whole and have one bend, or extend in a zigzag shape and have two or more bends (bends and / or bends). Furthermore, the manner of the bends may change every one or more predetermined number of bends, or the manner of the bends may change randomly. The specific value of the bend angle is arbitrary, and may be, for example, 90° or more or less than 90° (as in the example of FIG. 5 ).

[0078] In the example shown in the lower part of FIG. 6 , adjacent bridges 21 a are positioned at different positions in the D2 direction. More specifically, for example, bridges 21 a connecting the ends of the leads 19 on the +D2 side (the side opposite the resistor 9) and bridges 21 a connecting the intermediate positions of the leads 19 are alternately arranged in the D1 direction. Unlike the illustrated example, multiple bridges 21 a may be distributed at three or more different positions in the D2 direction. Furthermore, the arrangement pattern may be regular or random. The difference in position in the D2 direction (e.g., the distance between the centers of the bridges located closest to the +D2 side and the bridges located closest to the −D2 side) is arbitrary and may be, for example, more than or less than half the length of the overlap with the main portion 23 of the lead 19.

[0079] The example in the upper part of Figure 7 combines the example in the upper part of Figure 6 and the example in the lower part of Figure 6. That is, multiple bridges 21a extend at an angle with respect to the D1 direction, and adjacent bridges 21a are positioned differently in the D2 direction. More specifically, two bridges 21a form a single straight line, and this single straight line is arranged in the D1 direction. From another perspective, the positions of the ends of the +D2 side of each lead 19 are different (each lead has a different length), and bridges 21a connecting the midpoint of a long lead 19 to the end of a short lead 19 and bridges 21a connecting the ends of the short lead 19 to the end of a long lead 19 are alternately arranged in the D1 direction. Unlike the illustrated example, the two bridges 21a connected to each other may have different inclination angles. The explanations for the examples in the upper part of Figure 6 and the lower part of Figure 6 may be applied to the example in the upper part of Figure 7, unless a contradiction arises.

[0080] The example in the middle of Figure 7 is an example in which adjacent bridges 21a in the example in the top of Figure 7 are not connected to each other. Specifically, the bridge 21a on the -D2 side is located lower than in the example in the top of Figure 7. From another perspective, the bridge 21a on the -D2 side connects the midpoint of the long lead 19 to the midpoint of the short lead 19. The explanations for the example in the top of Figure 6, the example in the bottom of Figure 6, and the example in the top of Figure 7 may be used for the example in the middle of Figure 7, unless contradictions arise.

[0081] The example in the lower part of Figure 7 is the example in the upper part of Figure 6, but with the bridge 21a curved. More specifically, the bridge 21a extends from the middle of the lead 19 toward the +D1 side generally parallel to the D1 direction, then bends toward the +D2 side, and then extends generally parallel to the D1 direction to connect to the end of the adjacent lead 19 on the +D2 side. In terms of the bent bridge 21a, this example may be considered a variation of the example in the middle part of Figure 6. It may also be considered a combination of the example in the upper part of Figure 6 and the example in the middle part of Figure 6. The explanations of the example in the upper part of Figure 6 and the example in the middle part of Figure 6 may be used in the example in the lower part of Figure 7, unless a contradiction arises.

[0082] The specific examples of the basic patterns described above may be combined as appropriate. For example, although not specifically shown, a configuration in which part or all of the bridges 21a are curved, as in the example in the lower part of Fig. 7, may be applied to the examples in the upper and middle parts of Fig. 7 (it has already been mentioned that the bridges 21a may be curved in the example in the middle part of Fig. 6). Furthermore, a configuration in which the position of the bridges 21a is changed, as in the example in the lower part of Fig. 6, may be applied to an example in which the bridges 21a extend while bending, as in the example in the middle part of Fig. 6. Slanted bridges 21a, as in the example in the upper part of Fig. 6, and non-slanted bridges 21a, as in the example in the lower part of Fig. 6, may be mixed, or straight bridges 21a, as in the examples in the upper and / or lower parts of Fig. 6, and curved bridges 21a, as in the example in the middle part of Fig. 6, may be mixed.

[0083] 8 and 9 are schematic plan views showing other examples of the shape of the first conductor layer 15 around the specific wiring 21. The basic patterns (six types) of the specific wiring 21 shown in these figures are the same as the basic patterns (six types) shown in FIGS.

[0084] 8 and 9, the first conductor layer 15 may have a protruding portion 47 that protrudes further toward the +D2 side (the opposite side from the resistor 9) than the specific wiring 21. As shown in Figures 4 and 5, the protruding portion 47 may be entirely or partially covered by the main portion 23 of the second conductor layer 17. By providing such a protruding portion 47, for example, the position at which the first conductor layer 15 and the main portion 23 are joined may be expanded toward the +D2 side, improving the reliability of the joint therebetween.

[0085] The protrusion 47 can also be regarded as a part of the specific wiring 21 and / or the lead 19. However, for convenience in describing the embodiment, the protrusion 47 will be mainly expressed as being a separate part from the specific wiring 21 and the lead 19.

[0086] The position of the protrusion 47 in the D1 direction is arbitrary. In the examples in the upper and lower parts of Fig. 8 and the upper, middle, and lower parts of Fig. 9, the position of the protrusion 47 in the D1 direction is the same as the position of the lead 19. In the example in the middle part of Fig. 8, the position of the protrusion 47 in the D1 direction is between adjacent leads 19 (more specifically, the center), and from another perspective, it is the midpoint of the bridge 21a. From yet another perspective, the above position is the position of the apex on the +D2 side of the bent bridge 21a.

[0087] The shape of the protrusion 47 is arbitrary. In the illustrated example, the protrusion 47 is generally linear (or rectangular in another sense) extending parallel to the direction D2 with a constant width. Unlike the illustrated example, the protrusion 47 may be inclined with respect to the direction D2, may become thinner or thicker toward the tip, and / or may be curved.

[0088] The protrusion amount (D2 direction) and width (D1 direction) of the protrusion 47 are arbitrary. For example, the protrusion amount may be smaller, equal to, or larger than the length (D2 direction) of the lead 19 overlapping the main portion 23 and / or the amount of change in the position of the side edge portion 21b in the D2 direction. The width of the protrusion 47 may be smaller, equal to (in the illustrated example), or larger than the width of the lead 19.

[0089] (4.4. Mesh Pattern) FIG. 10 is a schematic plan view showing an example of a pattern different from the basic pattern.

[0090] 10, the specific wiring 21 is in a mesh pattern. In the example in the upper row, the mesh pattern is regular. In the example in the lower row, the mesh pattern is irregular.

[0091] More specifically, the specific wiring 21 in the example in the upper row of Fig. 10 has a plurality of first linear portions 21e1 extending in parallel with one another and a plurality of second linear portions 21e2 extending in parallel with one another (hereinafter, these two may be referred to as linear portions 21e without distinguishing between them). The plurality of first linear portions 21e1 and the plurality of second linear portions 21e2 intersect with one another to form a mesh shape. The plurality of linear portions 21e extend with a constant width.

[0092] The first linear portions 21e1 are inclined in a direction that leads closer to the +D1 side as they approach the +D2 side, and extend in a straight line parallel to each other from the +D2-side ends of the leads 19 toward the +D2 side. The second linear portions 21e2 are inclined in the opposite direction, and extend in a straight line parallel to each other from the +D2-side ends of the leads 19 toward the +D2 side. The inclination angles of the first linear portions 21e1 and the second linear portions 21e2 with respect to the D2 direction have opposite signs but the same absolute value. This forms a diamond-shaped mesh (non-arrangement areas of the first conductor layer 15).

[0093] The specific width of the multiple linear portions 21e is arbitrary, and may be, for example, smaller than, equal to, or larger than the width of the lead 19 (in the illustrated example). The inclination angle of the linear portions 21e with respect to the D2 direction is arbitrary, and may be, for example, 45° or more or less than 45° (in the illustrated example). The number of meshes (whose entire circumference is surrounded by linear portions 21e) positioned at different positions in the D2 direction is arbitrary, and may be one or more. In the illustrated example, there are three meshes.

[0094] Unlike the illustrated example, the inclination angles of the first linear portions 21e1 extending parallel to one another may be different from the inclination angles of the second linear portions 21e2 extending parallel to one another. From another perspective, the mesh may be a parallelogram shape rather than a diamond shape. Furthermore, three or more linear portions 21e may extend from one lead 19 (see the example in the lower part of Figure 13 described later).

[0095] The specific wiring 21 in the example in the lower part of Fig. 10 has, for example, a plurality of first linear portions 21e1 that are inclined so as to be positioned closer to +D1 as they approach the +D2 side, and a plurality of second linear portions 21e2 that are inclined so as to be positioned closer to the -D1 side as they approach the +D2 side, similar to the specific wiring 21 in the example in the upper part of Fig. 10. The intersection of the two forms a mesh shape.

[0096] The randomness may be achieved by any suitable method. In the illustrated example, randomness is imparted to the inclination angles of the plurality of linear portions 21e. In addition to the plurality of linear portions 21e extending from the plurality of leads 19 (their ends), the plurality of linear portions 21e are randomly arranged extending from midpoints of the linear portions 21e. The number of linear portions 21e extending from other portions of the plurality of leads 19 varies randomly. That is, three types of randomness are imparted. Note that randomness may be achieved by only one or two types.

[0097] In the illustrated example, the inclination angles of the plurality of first linear portions 21e1 are different from one another, so the first linear portions 21e1 also intersect with one another. The same is true for the second linear portions 21e2. This also forms a mesh.

[0098] 10, unlike the illustrated example, the linear portion 21e may not have a constant width and may include curved portions. The mesh-like specific wiring 21 may have a shape similar to that of a punched metal having circular meshes. The positions of the ends of the +D2 side of the multiple leads 19 in the D2 direction may not be constant.

[0099] 10 , the edges of the specific wiring 21 on both sides in the D2 direction form two side edges 21b, similar to the specific wiring 21 of the basic pattern. In both mesh-like specific wirings 21, the side edges 21b change position in the D2 direction in the region overlapping with the main portion 23. In other words, the mesh-like specific wiring 21 also achieves the effects described in the overview of the embodiment, similar to the basic pattern.

[0100] The examples in the upper and lower rows of Fig. 10 can be considered as examples in which a mesh pattern is added to the +D2 side of the multiple bridges 21a shown in the example in the middle row of Fig. 6. From this perspective, the mesh pattern can also be considered as a type of basic pattern.

[0101] (4.5. Corners of Edges) Fig. 11 is a diagram showing examples of corners of the specific wiring 21 and its surrounding area in the first conductor layer 15. The right diagram in Fig. 11 corresponds to an enlarged view of region XIa in Fig. 4. The left diagram in Fig. 11 corresponds to an enlarged view of region XIb in Fig. 5.

[0102] As shown in these figures, in the region where the first conductor layer 15 and the second conductor layer 17 (e.g., main portion 23) overlap, the corners of the outer edge of the first conductor layer 15 may be curved. In this case, the likelihood of unintended stress concentration occurring between the first conductor layer 15 and the second conductor layer 17, for example, during manufacture and / or use of the head 1, is reduced. Specific aspects of the curved corners are as follows.

[0103] The tip edge of the protrusion 47 may be curved (e.g., semicircular) and bulging outward. From another perspective, the corner between the tip edge (edge ​​on the +D2 side) and the side edge (edge ​​on the -D1 side or +D1 side) of the protrusion 47 may be chamfered by a curve. In the illustrated example, the curve of the chamfer on the -D1 side and the curve of the chamfer on the +D1 side can be considered to be smoothly connected.

[0104] Unlike the illustrated example, a leading edge parallel to the D1 direction may remain between the curve of the chamfer on the −D1 side and the curve of the chamfer on the +D1 side. Furthermore, a corner with a relatively large angle may remain between the curved leading edge and the straight side edge, or at one or both ends of the chamfer curve. The angle of such a corner may be, for example, greater than 135°.

[0105] The curvature of the curve of the leading edge and / or the curve of the chamfer is arbitrary. For example, the radius of curvature may be 1 / 2 of the width (e.g., the maximum width; the same applies below) of the protrusion 47 (as in the illustrated example), or it may be smaller or larger than this. The lower limit of the radius of curvature may be, for example, 1 / 10 or 1 / 5 of the width of the protrusion 47.

[0106] 11, of the two types of corners formed by the side edge 21b of the specific wiring 21 (bridge 21a) and the side edge of the lead 19, the corner 21f, which has an acute angle, is curved. As can be understood from this example, when the corners of the outer edge of the first conductor layer 15 are said to be curved, the above corners include not only corners where the first conductor layer 15 is convex, but also corners where the first conductor layer 15 is concave.

[0107] More specifically, at the corner 21f, the side edge 21b is cut out in a curved shape in the direction D2. From another perspective, the bridge 21a is narrowed. The side edge of the lead 19 is not cut out. The curve of the corner 21f smoothly connects with the side edge of the lead 19 (in the illustrated example) or forms a corner with a relatively large angle (e.g., 130° or more) with the side edge 21b. The curve of the corner 21f also forms a corner with a relatively large angle (e.g., 130° or more) with the side edge 21b.

[0108] Unlike the illustrated example, the obtuse angled corner of the two corners formed by the side edge 21b of the bridge 21a and the side edge of the lead 19 may also be curved. Furthermore, the curvature may be such that the bridge 21a becomes thicker rather than thinner.

[0109] As shown in the example on the left in Figure 11, corners 21m and 21n are curved, formed by bending side edges 21b of specific wiring 21. Corner 21m is formed by the intersection of adjacent bridges 21a. Corner 21n is formed by the bent portion of bridge 21a.

[0110] More specifically, at the corner 21m, the side edge 21b is cut out in a curved shape in the direction D2. From another perspective, each of the two bridges 21a is narrowed. The curve of the corner 21m forms a corner with a relatively large angle (e.g., 130° or more) with the linear portion of the side edge 21b. Unlike the illustrated example, the curvature may be such that the bridge 21a is thicker.

[0111] In addition, the corners 21n are curved in a shape that makes the bridges 21a thicker. That is, normal chamfering is performed by the curve. Unlike the illustrated example, the curvature may be in a form that makes the bridges 21a thinner.

[0112] Appropriate corners other than the above-described corners may be curved. For example, in the example on the left of Figure 11, the corner formed by the side edge 21b on the -D2 side and the side edge of the lead 19 may be curved. In an embodiment in which the protrusion 47 is not provided, the corner formed by the edge on the +D2 side of the lead 19 and the side edge 21b may be curved.

[0113] The curvature of the curves at the corners 21f, 21m, and 21n and other corners may be any desired value. For example, the radius of curvature may be set to be 1 / 20 or more and 1 / 5 or less of the distance (e.g., the minimum distance) between the side edges of adjacent leads 19 and / or the length of the bridge 21a parallel to the D2 direction (e.g., the minimum length when it is assumed that no notch is formed).

[0114] (4.6. Details of the Basic Pattern) Fig. 12 is a diagram showing other examples of the specific shapes and dimensions of the patterns in the upper and middle rows of Fig. 6. In this figure, arrow a1 indicates the direction of movement of the recording medium relative to the head main body 3.

[0115] In the example shown in the upper part of Fig. 6, the corner 21f recessed toward the -D2 side formed by the side edge 21b on the +D2 side and the corner 21f recessed toward the +D2 side formed by the -D2 side edge 21b are located at approximately the same position in the D2 direction. On the other hand, in the example shown in the upper part of Fig. 12, the former corner 21f is located closer to the -D2 side than the latter corner 21f. From another perspective, in the example shown in the upper part of Fig. 12, the inclination angle of the bridge 21a with respect to the D1 direction is relatively large.

[0116] In the example in the middle of Fig. 6, corner 21m formed by side edge 21b on the +D2 side and recessed toward -D2, and corner 21n formed by side edge 21b on the +D2 side and recessed toward +D2, are located at approximately the same position in the D2 direction. On the other hand, in the example in the bottom of Fig. 12, corner 21m is located closer to the -D2 side than corner 21n. From another perspective, in the example in the bottom of Fig. 12, the inclination angle with respect to the D1 direction before and after the bent portion of bridge 21a is relatively large.

[0117] In the examples in the upper and lower rows of FIG. 12 , the difference d1 between the corner (21f or 21m) recessed toward the −D2 side and the corner (21f or 21n) recessed toward the +D2 side may have any size. For example, the difference d1 may be 1 / 10 or more, 1 / 5 or more, or 1 / 2 or more of the length of the specific wiring 21 parallel to the D2 direction (e.g., the minimum length when notched). There is no particular upper limit. In an aspect in which a corner is notched as illustrated in FIG. 11 , the specific example of the difference d1 described above may be applied to the difference d1 when the notch is ignored, or may be applied to the difference d1 when the notch is taken into account.

[0118] Unlike the examples in Figures 6 and 12, the corner (21f or 21m) recessed toward the -D2 side may be located on the +D2 side relative to the corner (21f or 21n) recessed toward the +D2 side (see the example on the right in Figure 11). In this case, the difference d2 (Figure 11) between the positions of the two in the D2 direction is also arbitrary. For example, the specific example of the difference d1 above may be used as the difference d2.

[0119] Although the above description has been given taking the patterns in the upper and middle rows of FIG. 6 as examples, the above description of the presence or absence and magnitude of the difference d1 or difference d2 may be applied to other patterns.

[0120] (4.7. Branching of Extension Portion) FIG. 13 is a diagram showing an example of the configuration of a portion of the comb-tooth portion 11 a of the common electrode 11 .

[0121] As already mentioned, the main portion 23 does not have to overlap the entire specific wiring 21. Fig. 13 illustrates an example in which the main portion 23 overlaps only a portion of the specific wiring 21. Specifically, this illustrates an example in which the portion of the specific wiring 21 that is not covered by the main portion 23 forms two or more branches 21d (two in the upper example, three in the lower example) that branch off from each lead 19 and reach the main portion 23.

[0122] More specifically, in the example in the upper part of Fig. 13, the lower edge of the main portion 23 crosses the bridge 21a in the example in the middle part of Fig. 6 (more specifically, in the example in the lower part of Fig. 12 where difference d1 occurs), so that the portions of adjacent bridges 21a connected to the same lead 19 form two branches 21d branching off from one lead 19.

[0123] In the example in the lower part of Fig. 13, the specific wiring 21 has a mesh pattern (but only one row of mesh) like the example in the upper part of Fig. 10, and linear portions 21e are added that are parallel to the lead 19 in the direction D2. The lower edge of the main portion 23 crosses the lead 19 side of the three linear portions 21e. This forms three branches 21d branching off from one lead 19. Note that, as indicated by the reference numerals 21a, the specific wiring 21 in the example in the lower part of Fig. 13 can also be regarded as a type of basic pattern.

[0124] As described above, the main wiring portion 11b of the comb-tooth portion 11a may be defined as a portion of the first conductor layer 15 (specific wiring 21 and lead 19) that overlaps with the main portion 23, and the portion configured by the main portion 23. The extension portion 11c of the comb-tooth portion 11a may be defined as a portion of the specific wiring 21 and lead 19 that does not overlap with the main portion 23. Therefore, the branch 21d may be considered to be the portion of the extension portion 11c on the side of the main wiring portion 11b.

[0125] The number of branches 21d is arbitrary and may be four or more, unlike the illustrated example. In a mode in which branches 21d are provided, the mode of the specific wiring 21 may be a basic pattern or a mesh pattern, as can be seen from the examples in the upper and lower parts of Figure 13. As long as the branches 21d can be formed, the various patterns exemplified above (e.g., a pattern having protrusions 47) may be used.

[0126] The descriptions of the basic pattern (particularly the example in the middle of FIG. 6 and examples similar thereto) and the description of the net pattern may be applied to examples in which branches 21d are provided. Therefore, for example, the width of the branches 21d is arbitrary. The branches 21d may be linear (as in the illustrated example) or curved. The inclination angle of the branches 21d relative to the D1 direction (or D2 direction) is arbitrary. The number, shape, inclination angle, etc. of the branches 21d may have regularity (as in the illustrated example) or may not have regularity.

[0127] (4.8. Dimensions Related to Overlap Between Specific Wiring and Main Portion) The degree of overlap between the first conductor layer 15 (particularly the specific wiring 21) and the main portion 23 is arbitrary. For example, as illustrated in Figures 4 and 5, the specific wiring 21 may (but does not have to) fit within the region on the resistor 9 side when the width W1 of the main portion 23 is divided into two equal parts. Furthermore, the portion of the first conductor layer 15 (which may include the protruding portion 47) that overlaps with the main portion 23 may (but does not have to) fit within the region on the resistor 9 side when the width W1 of the main portion 23 is divided into two equal parts.

[0128] As described above, the head main body 3 may have various sizes. Consequently, the specific values ​​of the width (length in a direction perpendicular to the center line) or length parallel to the D2 direction of the bridge 21a (or linear portion 21e; ​​the same applies hereinafter) and the width W1 of the main portion 23, and the difference therebetween, are arbitrary. For example, the width or length parallel to the D2 direction of the bridge 21a may be 5 μm or more and 150 μm or less. The width W1 may be 100 μm or more and 1 mm or less, provided that it is larger than the width of the bridge 21a. The width W1 may be, for example, 5 times or more and 30 times or less the width or length parallel to the D2 direction of the bridge 21a.

[0129] Furthermore, the area of ​​the portion of the first conductor layer 15 that overlaps with the main portion 23 may be 80% or less, 60% or less, 50% or less, or 30% or less of the area of ​​the main portion 23 (it may be more than 80%). When comparing these areas, the areas of the first conductor layer 15 and the main portion 23 may not be the areas of the portions located between the two sub-wiring portions 11d in the D1 direction, but may be the areas ranging from the end on the +D1 side to the end on the -D1 side of the specific wiring 21. In other words, the above area ratio is the value obtained by integrating in the D1 direction the proportion of the length in the D2 direction of the portion of the first conductor layer 15 that overlaps with the main portion 23 to the width W1 of the main portion 23.

[0130] As described above, the main portion 23 may extend over two or more surfaces of the substrate 7, and the second direction is not limited to a linear direction such as the D2 direction, but may also be a direction that rotates around the D1 axis. The above-described dimensional ratios (including area ratios) may hold not only in an embodiment in which the entire main portion 23 is located on one surface, but also in an embodiment in which the main portion 23 extends over two or more surfaces, and may hold for the entire area over those two or more surfaces. However, even in such an embodiment, the above dimensional ratios may hold when focusing on only a portion of the surfaces (e.g., the upper surface 7a of the substrate 7).

[0131] (5. Manufacturing Method of Head Body) The manufacturing method of the head body may be various methods, for example, known methods, except for the specific pattern of the first conductor layer 15, etc.

[0132] Specifically, for example, each layer may be formed on the surface of the substrate 7 by an appropriate film formation technique. Examples of film formation methods include chemical vapor deposition (CVD), physical vapor deposition (PVD), and printing. Examples of CVD include thermal CVD and plasma CVD. Examples of PVD include sputtering and ion plating. Examples of printing include gravure printing and screen printing. In the case of CVD and PVD, patterning may be performed by performing CVD or PVD through a mask, or by etching after CVD or PVD.

[0133] More specifically, the first conductor layer 15 may be formed by, for example, gravure offset printing (intaglio offset printing). For example, recesses are formed in the surface of a plate, and a material (e.g., conductive paste) that will become the first conductor layer 15 is placed on the surface with the recesses. Any unnecessary conductive paste is then scraped off from the surface with a doctor blade. The material is then transferred from the plate to a blanket, and then from the blanket to the substrate 7. The conductive paste is then fired.

[0134] The second conductor layer 17 may be formed by, for example, screen printing. For example, a material (e.g., a conductive paste) that will become the second conductor layer 17 is placed on a screen, and the conductive paste is transferred to the substrate 7 by sliding a squeegee over the screen. The conductive paste is then fired. The first conductor layer 15 and the second conductor layer 17 may be fired together or separately.

[0135] (6. Printer) Fig. 14 is a schematic diagram showing the configuration of a printer 101 having a head 1. The configuration of the printer 101 may have various configurations, excluding the configuration of the head 1 (more specifically, the specific wiring 21 and its peripheral portion), and may be, for example, a known configuration. The configuration shown in Fig. 14 is merely one example.

[0136] In addition to the head 1, the printer 101 may have, for example, the following components: - Conveyance device 103: For example, conveys the recording medium P (for example, thermal paper). - Platen roller 105: For example, presses the recording medium P against the multiple heat generating portions 5 (strictly speaking, the durable film 39 covering the multiple heat generating portions 5). - Power supply device 107: For example, supplies power to the head 1. - Control device 109: For example, controls the head 1, the conveyance device 103, and the power supply device 107.

[0137] (7. Summary of the embodiment) As described above, the thermal head 1 according to the embodiment has a plurality of heat generating portions 5, a first conductor layer 15, and a second conductor layer 17. The plurality of heat generating portions 5 are arranged in a first direction (direction D1). The second conductor layer 17 has a lower electrical resistivity than the first conductor layer 15. The first conductor layer 15 has a plurality of leads 19 and specific wiring 21. The leads 19 extend from the plurality of heat generating portions 5 in a second direction (direction D2) that intersects with the direction D1. The specific wiring 21 connects the leads 19 to one another. The second conductor layer 17 has a main portion 23 that covers at least a portion of the specific wiring 21. The specific wiring 21 overlaps a portion of the length (width W1) of the main portion 23 in the direction D2. At least one of the side edge portions 21b on both sides in the D2 direction of the specific wiring 21 changes its position in the D2 direction depending on its position in the D1 direction in the region overlapping the main portion 23.

[0138] From another perspective, the recording apparatus (printer 101) according to the embodiment has the head 1 and a moving section (transport device 103) that moves the head 1 and the recording medium relative to each other.

[0139] Therefore, as described in the overview of the embodiment, the bonding area between the specific wiring 21 and the main portion 23 can be reduced while maintaining the reliability of the bonding strength between them. By reducing the bonding area, the likelihood of the material of the first conductor layer 15 diffusing into the main portion 23 is reduced, and the function of allowing current to flow through the main portion 23 with low electrical resistance is achieved. As a result, the difference in current loss between the end and center of the main wiring portion 11b is reduced, reducing the likelihood of unintended density unevenness appearing on the recording medium. In other words, image quality is improved.

[0140] The first conductor layer 15 may have a plurality of protruding portions 47 (see, for example, FIGS. 4, 5, 8, and 9). The protruding portions 47 may protrude from the specific wiring 21 toward the opposite side (+D2 side) from the plurality of heat generating portions 5, and may be covered by the main portion 23.

[0141] In this case, for example, the position where the first conductor layer 15 and the main portion 23 are joined is expanded toward the +D2 side, improving the reliability of the joint between them. Since the first conductor layer 15 and the main portion 23 do not overlap between the multiple protrusions 47, an increase in the contact area between the first conductor layer 15 and the main portion 23 is suppressed.

[0142] The corners (21f, 21m and / or 21n) of the outer edge of the first conductor layer 15 may be curved in the region overlapping the main portion 23 (FIG. 11).

[0143] In this case, for example, the likelihood of stress concentrating on the corners during the manufacture and / or use of the head 1 is reduced, improving the reliability of the bond between the first conductor layer 15 and the main portion 23. Furthermore, in an embodiment in which the first conductor layer 15 is formed using an intaglio plate, collision and friction between the doctor blade and the corners of the recesses of the plate is alleviated, resulting in a longer life for the doctor blade and / or the plate.

[0144] The corners (21f and / or 21m) may be curved in a concave shape, so that the specific wiring 21 becomes thinner at the corners (FIG. 11).

[0145] In this case, for example, the recessed portion of the corner portion contributes to reducing the area of ​​the specific wiring 21. As a result, for example, the probability that the material of the specific wiring 21 will diffuse into the main portion 23 is further reduced.

[0146] The specific wiring 21 (or the entire first conductor layer 15 including the protrusion 47) may be located closer to the multiple heat generating portions 5 (-D2 side) than the center of the main portion 23 in the second direction (D2 direction) (Figures 4 and 5).

[0147] In this case, it is easy to ensure that the area of ​​the main portion 23 does not overlap with the first conductor layer 15. As a result, the effect of reducing the diffusion between the material of the first conductor layer 15 and the material of the main portion 23 is improved.

[0148] The specific wiring 21 may have two or more branches 21d branching from each of the leads 19 and reaching the main portion 23 for each of the multiple leads 19 (FIG. 13).

[0149] In this case, for example, the number of connection paths between the extension portion 11c (the lead 19 and the portion of the specific wiring 21 not covered by the main portion 23) and the main portion 23 increases. As a result, for example, the wiring resistance of the extension portion 11c decreases, reducing the power consumption of the head 1. Furthermore, for example, even if one of the branches 21d breaks due to thermal stress or the like generated between the main portion 23 and the first conductor layer 15 while the head 1 is in use, the remaining branches 21d maintain electrical continuity in the extension portion 11c. Therefore, the corresponding heat-generating portion 5 does not become unable to print at all, but merely experiences a decrease in print density, for example. As a result, depending on the image quality desired by the user, it may be possible to continue using the head 1.

[0150] The specific wiring 21 may have a plurality of bridges 21a. Each bridge 21a may span adjacent ones of the plurality of leads 19. Each bridge 21a may be inclined with respect to the first direction (direction D1) (see, for example, FIGS. 4, the upper and middle sections of FIG. 6, and the upper to lower sections of FIG. 7).

[0151] In this case, for example, a simple configuration of tilting the bridge 21a can change the position of the lateral edge 21b in the D2 direction. Furthermore, as shown in the upper example of FIG. 6 , it is possible to change the position of the lateral edge 21b in the D2 direction while maintaining a linear shape with a constant width. In this case, it is easier to change the position of the lateral edge 21b in the D2 direction, even when the gap between the leads 19 is small, compared to a configuration in which the bridge 21a is curved (e.g., the middle example of FIG. 6 ). Furthermore, for example, when a virtual line (not shown) parallel to the D1 direction is assumed, the virtual line intersects the lateral edge 21b of the bridge 21a (for example, in the lower example of FIG. 6 , the virtual line does not intersect the lateral edge 21b). Therefore, when using an intaglio plate, for example, a doctor blade parallel to the D1 direction is unlikely to penetrate into the recess corresponding to the bridge 21a.

[0152] Each of the multiple bridges 21a may be curved (e.g., as shown in FIGS. 5 and 6, the middle section, and the lower section of FIG. 7).

[0153] In this case, for example, a simple bending structure of the bridge 21a can change the position of the side edge 21b in the D2 direction. Furthermore, as shown in the middle example of FIG. 6, the shape of the bridge 21a can be made symmetrical while still achieving a change in the position of the side edge 21b in the D2 direction (for example, the bridge 21a is not symmetrical in the upper example of FIG. 6). This, for example, can equalize the mechanical or electrical influence that each bridge 21a exerts on the leads 19 on both sides. As a result, the likelihood of unintended shape or electrical errors occurring is reduced. Furthermore, as in the case of tilting the bridge 21a, a virtual straight line (not shown) parallel to the D1 direction crosses the side edge 21b, making it difficult for a doctor blade parallel to the D1 direction to penetrate into the recess corresponding to the bridge 21a.

[0154] Among the multiple bridges 21a, adjacent bridges 21a may be positioned differently in the second direction (direction D2) (for example, the lower part of FIG. 6, the upper and middle parts of FIG. 7).

[0155] In this case, for example, as in the example in the lower part of Fig. 6, adjacent leads 19 can be connected at the shortest distance, minimizing the area of ​​the bridges 21a and changing the position of the specific wiring 21 in the D2 direction. Also, as in the examples in the upper and middle parts of Fig. 7, for example, by tilting (or bending) the bridges 21a and varying the positions of adjacent bridges 21a, the arrangement range of the specific wiring 21 in the D2 direction can be expanded, thereby improving the reliability of the bond between the first conductor layer 15 and the main portion 23. In either case, the bond area can be reduced while improving the reliability of the bond.

[0156] The multiple bridges 21a may be arranged so that the innermost portion (corner 21f or 21m) of the recess formed by the lateral edge 21b on the first side (+D2 side) in the second direction (D2 direction) is located on the -D2 side of the innermost portion (corner 21f or 21n) of the recess formed by the lateral edge 21b on the second side (-D2 side) in the D2 direction (upper and lower rows of Figure 12).

[0157] In this case, for example, the change in the position of each of the side edge portions 21b on both sides in the D2 direction can be said to be large. Therefore, the effect of improving the reliability of the bonding while reducing the area of ​​the first conductor layer 15 is enhanced. Furthermore, focusing on the manufacturing process, it is possible to reduce the number of areas where the recesses of the intaglio plate (areas corresponding to the specific wiring 21) are continuous in the D1 direction, thereby reducing the likelihood that the doctor blade will fall into the recesses of the plate. As a result, for example, it is possible to reduce pattern shape disturbances and / or film thickness unevenness in the first conductor layer 15.

[0158] The specific wiring 21 may be in a mesh form (such as the upper and lower parts of FIG. 10).

[0159] In this case, for example, assuming that there are two imaginary lines (not shown) parallel to the D1 direction passing through the position on the −D2 side of the specific wiring 21, and another imaginary line (not shown) parallel to the D1 direction passing through the position on the +D2 side of the specific wiring 21, the distribution of the first conductor layer 15 in the region sandwiched between the two imaginary lines becomes more uniform compared to the basic pattern ( FIG. 6 , etc.), thereby improving the reliability of the connection between the first conductor layer 15 and the main portion 23 uniformly in the region.

[0160] The area where the first conductor layer 15 overlaps the main portion 23 may be 80% or less of the area of ​​the main portion 23 .

[0161] In this case, for example, the probability of interdiffusion between the first conductor layer 15 and the main portion 23 is reduced to a certain extent, making it easier to achieve the above-mentioned effects.

[0162] In the above embodiment, the printer 101 is an example of a recording device, and the transport device 103 is an example of a moving unit.

[0163] The technology according to the present disclosure is not limited to the above-described embodiments and may be implemented in various forms.

[0164] The recording device may be a plotter. The recording device may be a handheld printer that is held and moved by a user and moves relative to the recording medium. The recording device may be one in which the recording medium and the head are moved relative to each other by moving the head using a robot or the like.

[0165] The recording medium is not limited to paper. For example, the recording medium may be cloth, wood, or tile with a heat-sensitive layer formed on its surface. Furthermore, in an embodiment in which transfer is performed, such as an embodiment using an ink ribbon, it is clear that various media (e.g., cloth, wood, or tile) can be used instead of paper.

[0166] From this disclosure, inventions may be extracted that do not require the side edge of the specific wiring to change position in the second direction, etc. For example, an invention may be extracted in which the first conductor layer has a protruding portion that protrudes further than the specific wiring on the side opposite the heat generating portion. Also, for example, an invention may be extracted in which part or all of the specific wiring is mesh-shaped.

[0167] 101...printer (recording device), 1...head (thermal head), 3...head body (thermal head), 5...heat generating portion, 15...first conductor layer, 17...second conductor layer, 19...lead, 21...specific wiring, 23...main portion.

Claims

1. A thermal head comprising: a plurality of heat generating portions arranged in a first direction; a first conductor layer; and a second conductor layer having a lower electrical resistivity than the first conductor layer, wherein the first conductor layer has a plurality of leads extending from the plurality of heat generating portions in a second direction intersecting the first direction; and specific wiring connecting the plurality of leads to each other, wherein the second conductor layer has a main portion covering at least a portion of the specific wiring, the specific wiring overlaps with a portion of the length of the main portion in the second direction, and at least one of the side edges on both sides of the second direction of the specific wiring changes position in the second direction depending on its position in the first direction in the region overlapping with the main portion.

2. A thermal head as described in claim 1, wherein the first conductor layer has a plurality of protruding portions that protrude beyond the specific wiring on the opposite side to the plurality of heat generating portions and are covered by the main portion.

3. A thermal head according to claim 1 or 2, wherein the corners of the outer edge of the first conductor layer are curved in the area overlapping with the main portion.

4. The thermal head according to claim 3, wherein the specific wiring is narrowed at the corner by being curved in a concave shape.

5. A thermal head according to any one of claims 1 to 4, wherein the specific wiring is located closer to the plurality of heat generating parts than the center of the main part in the second direction.

6. A thermal head according to any one of claims 1 to 5, wherein the specific wiring has two or more branches that branch off from each of the multiple leads and reach the main portion.

7. A thermal head as claimed in any one of claims 1 to 6, wherein the specific wiring has a plurality of bridges each spanning adjacent ones of the plurality of leads, and each of the plurality of bridges is inclined with respect to the first direction.

8. A thermal head according to any one of claims 1 to 7, wherein the specific wiring has a plurality of bridges each spanning adjacent ones of the plurality of leads, and each of the plurality of bridges is curved.

9. A thermal head as claimed in any one of claims 1 to 8, wherein the specific wiring has a plurality of bridges each spanning adjacent ones of the plurality of leads, and among the plurality of bridges, adjacent bridges are positioned differently in the second direction.

10. A thermal head as claimed in any one of claims 1 to 9, wherein the specific wiring has a plurality of bridges each spanning adjacent ones of the plurality of leads, and the innermost portion of a recess formed by a lateral edge on a first side in the second direction of the plurality of bridges is located on the second side of the innermost portion of a recess formed by a lateral edge on a second side in the second direction.

11. A thermal head according to any one of claims 1 to 10, wherein the specific wiring is in a mesh form.

12. A thermal head according to any one of claims 1 to 11, wherein the area where the first conductor layer overlaps with the main portion is 80% or less of the area of ​​the main portion.

13. A recording device comprising: a thermal head according to any one of claims 1 to 12; and a moving section for relatively moving said thermal head and a recording medium.

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