Thermal head and recording device

Abstract

The thermal head has a plurality of heat generating parts (5), a first conductive layer (15), and a second conductive layer (17). The plurality of heat generating parts (5) are arranged in a first direction (D1). The second conductive layer (17) has a lower electrical resistivity than the first conductive layer (15). The first conductive layer (15) has a plurality of leads (19) and a specific wiring (21). The multiple 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 multiple leads (19) to each other. The second conductive 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 of the main portion (23) in the second direction (D2). At least one of the side edges on both sides in the second direction (D2) of the specific wiring (21) changes its position in the second direction (D2) depending on its position in the first direction (D1) in the region overlapping with the main portion (23).

Description

[Technical field]

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

[0002] Thermal heads are known that heat thermal paper to print on the thermal paper or heat an ink ribbon to print on a recording medium (e.g., paper) (see, for example, Patent Document 1 below). Thermal heads have multiple heat generating parts that are used for the above-mentioned heating. The multiple heat generating parts 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 parts. The common electrode includes a portion extending along the arrangement of the plurality of heat generating parts, and is connected to the plurality of heat generating parts. The plurality of individual electrodes are individually connected to the plurality of heat generating parts. By individually controlling the potentials applied to the plurality of individual electrodes, the temperatures of the plurality of heat generating parts are individually controlled, and thus any image is formed on the recording medium. In the thermal head of Patent Document 1, a gold (Au) conductor pattern and a silver (Ag) conductor pattern are used in combination. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-78589 A Summary of the Invention

[0005] A thermal head according to one embodiment of the present disclosure has a plurality of heat generating parts, a first conductor layer, and a second conductor layer. The plurality of heat generating parts 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 plurality of leads extend from the plurality of heat generating parts 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 edges on both sides of the second direction of the specific wiring changes its 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 an aspect of the present disclosure includes the thermal head and a moving unit that moves the thermal head and a recording medium relative to each other. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a schematic exploded perspective view of a thermal head according to an embodiment. [Diagram 2] FIG. 2 is a plan view showing a part of the thermal head shown in FIG. [Diagram 3] 3 is a cross-sectional view taken along line III-III in FIG. 2 . [Figure 4] 3 is a plan view showing a first example of a configuration in region IV of FIG. 2; [Diagram 5] 3 is a plan view showing a second example of the configuration in region IV of FIG. 2; [Figure 6] 2 is a schematic diagram showing first to third patterns of a common electrode included in the thermal head of FIG. 1. [Figure 7] 5A to 5C are schematic diagrams showing fourth to sixth patterns of a common electrode. [Figure 8] Schematic diagrams showing seventh to ninth patterns of a common electrode. [Figure 9] Schematic diagrams showing tenth to twelfth patterns of a common electrode. [Figure 10]Schematic diagrams showing thirteenth and fourteenth patterns of a common electrode. [Figure 11] Schematic diagram showing 15th and 16th patterns of a common electrode. [Figure 12] FIG. 18 is a schematic diagram showing 17th and 18th patterns of a common electrode. [Figure 13] Schematic diagram showing 19th and 20th patterns of a common electrode. FIG. [Figure 14] FIG. 1 is a cross-sectional view of a printer according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment according to 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 match the actual ones. In addition, 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 the shapes and / or dimensions may be extracted from the drawings.

[0009] For convenience, the drawings are provided with a Cartesian coordinate system D1D2D3, and terms such as D1 direction, D2 direction, and D3 direction are 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 a term for a direction perpendicular to the longitudinal direction of the head, the arrangement direction of the multiple heat generating parts, and / or the direction of relative movement between the head and the recording medium. The term D2 direction may be replaced with a term for a direction perpendicular to the lateral direction of the head, the arrangement direction, and / or the direction of the relative movement. The term D3 direction may be replaced with a term for a normal direction of the head body. The thermal head and recording device according to the embodiment may be used in any orientation. However, for convenience, terms assuming that the +D3 side is upward may be used.

[0010] (Overview of the embodiment) 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 body 3 that is directly responsible for recording (e.g., printing) on ​​a recording medium (e.g., paper). The head 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 together with the ink ribbon over the plurality of heat generating parts 5.

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

[0013] Fig. 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 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. Parts 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 parts 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 overlapped with the surface of the substrate 7. However, for the sake of convenience, in the description of the embodiments, the presence of layers interposed between these components and the substrate 7 may be ignored.

[0016] In the illustrated example, the resistor 9 extends in the D1 direction. 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. The potential and the like of the drive signal are controlled for each individual electrode 13, thereby individually controlling the temperatures of the heat generating portions 5.

[0018] Fig. 4 is an enlarged view of region IV in Fig. 2. For convenience, polka dot hatching is applied to the surface (i.e., the surface other than the cross section) of a first conductor layer 15 described later. Fig. 5 is a view showing an example of the configuration in region IV that is different from that 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 a portion of the first conductor layer 15 that is covered by the main portion 23. The extension portion 11c is formed by a 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. In addition, for example, a material for the second conductor layer 17 that is less expensive than the material for the first conductor layer 15 can be used, thereby reducing the cost of the head body 3.

[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 the characteristics of the multiple heat generating parts 5 being degraded. 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 part of the length (width W1) in the D2 direction of the main portion 23. Also, the specific wiring 21 extends in the D1 direction while changing its position in the D2 direction. From another perspective, at least one (both in the illustrated example) 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 with 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. In turn, 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] And, by exerting the effect of making the current flow with low electrical resistance in the main portion 23, the difference in current loss between the end and center of the main wiring portion 11b is reduced. As a result, the probability of unintended temperature variations occurring in the multiple heat generating portions 5 is reduced. In turn, the probability of unintended density unevenness occurring on the recording medium is reduced. In other words, image quality is improved.

[0027] On the other hand, since the position of the side edge portion 21b of the specific wiring 21 is changed in the D2 direction, the range of positions where the specific wiring 21 and the main portion 23 are joined is expanded in the D2 direction compared to a mode in which the specific wiring 21 extends linearly in the D1 direction. For example, when a virtual line (not shown) parallel to the D1 direction passing through the position on the -D2 side of the specific wiring 21 and a virtual line (not shown) parallel to the D1 direction passing through the position on the +D2 side of the specific wiring 21 are assumed, the area sandwiched between the two virtual lines is expanded. 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 roughly described below in the following order. 1. Overall structure of the head (Fig. 1) 2. Head body (Fig. 2 to Fig. 5) 2.1. General 2.2. Substrate, resistor, common electrode, and individual electrodes 2.3. Other Components 3. First conductor layer and second conductor layer 4. Specific wiring and surrounding areas 4.1. Overview of basic patterns (Figures 4 and 5) 4.2. Variations of the basic pattern (Figures 6 and 7) 4.3. Protrusions (Figures 8 and 9) 4.4.Net pattern (Figure 10) 4.5. Corners of the outer edge (Fig. 11) 4.6. Details of the basic pattern (Fig. 12) 4.7. Branching of extension section (Fig. 13) 4.8. Dimensions related to overlap between specific wiring and main part 5. Manufacturing method of the head body 6. Printer (Figure 14) 7. Summary of the embodiment

[0029] (1. Overall head structure) The head 1 may have various configurations, for example, a known configuration, except for the configuration of the specific wiring 21 and its surrounding parts. 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] As shown in FIG. 1, in addition to a head main body 3, the head 1 may include the following components. Connector 25: For example, electrically connects the head body 3 to an external device (for example, a power supply device 107 and a control device 109 shown in FIG. 14, which will be described later). Heat sink 27: For example, it absorbs unnecessary heat from the head body 3 and releases it. Adhesive member 29: For example, it adheres the lower surface of the head body 3 and the heat sink 27 to each other.

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

[0032] (2. Head 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 portion.

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

[0034] 1 and 2, the heat generating parts 5 are located on the upper surface 7a of the substrate 7. Unlike the illustrated example, the heat generating parts 5 may be located on a side surface of the substrate 7 (e.g., a surface facing the +D2 side), or on an inclined surface formed by chamfering a corner between the upper surface 7a and the side surface. Similarly, all or a part of the comb tooth portion 11a of the common electrode 11 and the portions of the individual electrodes 13 connected to the heat generating parts 5 may be located on a side surface or an inclined surface, not on the upper surface 7a. In the comb tooth portion 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 extensions 11c and the individual electrodes 13 are alternately arranged in the D1 direction. Unlike the illustrated example, the extensions 11c and the individual electrodes 13 may be arranged such that their tips face each other in the D2 direction with a gap therebetween. From another perspective, the extensions 11c and the individual electrodes 13 (their tips) may be arranged at the same positions as each other in the D1 direction. Then, a portion of the resistor 9 located between the tip of the extension 11c and the tip of the individual electrode 13 may function as the heat generating portion 5. The common electrode 11 and the individual electrodes 13 may overlap the resistor 9 from below (illustrated example) or from above.

[0036] Also, for example, the head body 3 may have a plurality of auxiliary heating parts that supplementarily heat the recording medium before the recording medium reaches the plurality of heating parts 5, unlike the example shown in the figure. The application of voltage to such auxiliary heating parts may be configured, for example, by a plurality of individual electrodes 13, a plurality of 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, in addition to the shape of the example shown in the figure, the individual electrodes 13 may have a portion that folds back from that shape to the -D2 side and reaches the auxiliary heating parts. Also, one auxiliary heating part extending in the D1 direction may be provided.

[0037] Also, for example, the size of the head body 3 is arbitrary. From another point of view, the size of the recording medium is arbitrary. For example, paper as a recording medium may be small like a receipt, may be a size commonly used in an office, or may be large like a poster. As will be understood from the description, the dimensions of each part (substrate 7, resistor 9, common electrode 11, individual electrode 13, etc.) constituting the head body 3 are arbitrary. Also, in the illustrated example, the arrangement direction of the multiple heat generating parts 5 and the longitudinal direction of the head body 3 coincide with each other, but the two directions may be perpendicular to each other.

[0038] (2.2. Substrate, resistor, common electrode and individual electrode) As will be understood from the above, various configurations may be used for the substrate 7, resistor 9, common electrode 11, and individual electrodes 13. In the following, 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 shape of the substrate 7 is generally a plate shape with the thickness direction being in the D3 direction, and its shape in a plan view is a rectangle having 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. Examples of materials for the resistor 9 include TaN, TaSiO, TaSiNO, TiSiO, TiSiCO, NbSiO, and RuO2. The resistor 9 extends, for example, in a position close to 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, a circular arc shape) that bulges outward or a straight shape.

[0041] The common electrode 11 is, for example, entirely located on the upper surface 7a of the substrate 7. The common electrode 11 also has, for example, the above-mentioned comb tooth portion 11a and a sub-wiring portion 11d for connecting the comb tooth portion 11a and 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 D1 direction (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 D1 direction. 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 extensions 11c of the comb tooth portion 11a have, for example, the same configuration as each other and are arranged at a constant pitch in the D1 direction. Each extension 11c extends, for example, from the main wiring portion 11b toward the resistor 9 in parallel (linearly) in the D2 direction and crosses the entire width of the resistor 9 in a plan view. For example, the portion of the extension 11c crossing 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 explanation regarding 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 there is a contradiction.

[0044] The individual electrodes 13 extend, for example, from the opposite side of the common electrode 11 to the main wiring portion 11b 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 one another in the portions that traverse the resistor 9 (the ends on the resistor 9 side), and the 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) to be described later. The shape of the portions is arbitrary.

[0045] As described above, 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 of the substrate 7. Also, 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 may not be a linear direction, and may be a circumferential direction that extends toward the side surface on the +D2 side on the upper surface 7a, toward the lower surface, and toward the -D2 side. Also, the main wiring portion 11b (or the main portion 23) may have a shape that cannot be conceptualized as a width in the second direction (in other words, it may have a shape that cannot be conceptualized as extending in the first direction). However, in the description of the embodiment, for convenience, expressions based on the illustrated example may be used without special notice.

[0046] (2.3. Other Components) As shown in FIG. 2, the head main body 3 may have the following components in addition to the above components. One or more (three in the illustrated example) driving ICs 31: for example, generate driving signals input to the individual electrodes 13. The driving ICs 31 may not be considered as being a component of the head main body 3. A plurality of connection wires 33: For example, connects the driving IC 31 and the connector 25.

[0047] The driving IC 31 is mounted on the substrate 7, and generates a driving signal according to a signal input from the connector 25 via the connection wiring 33, and inputs the driving signal to the individual electrodes 13. The connection wiring 33 is formed of a conductor layer located on the surface of the substrate 7. The connection wiring 33 may have any shape. 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 main body 3 may have the following components in addition to the substrate 7, the first conductor layer 15, and the second conductor layer 17 described above. Heat generating portion glaze 35a: For example, it contributes to heat storage under the heat generating portion 5. Wiring portion glaze 35b: For example, a surface with less irregularities than the surface of substrate 7 is formed on substrate 7 (under wiring). Protective film 37: For example, it insulates the electrodes, wiring, and resistors. Durable film 39: For example, this improves the durability of the head body 3 against the sliding of a 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, to protect the driving IC 31. Connector hard coat 45: For example, it 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 shape with the upper surface bulging outward in cross section. The cross section has a constant shape and dimensions and extends in the direction D1. The portion of the extension 11c on the resistor 9 side, the portion of the individual electrode 13 on the resistor 9 side, 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 portion of the sub-wiring portion 11d, the -D2 side portion of the individual electrode 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 (e.g., the entirety), the main portion 23 (e.g., the entirety), a middle portion of the extension portion 11c, a middle portion of the sub-wiring portion 11d, and a middle portion of the individual electrode 13.

[0053] The heat generating portion glaze 35a and the wiring portion glaze 35b are made of glass. These may be regarded as a 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. The protective film 37 extends over almost the entire upper surface 7a of the substrate 7, except for an area where the driving IC 31 is disposed and an area where the connector 25 is disposed. Furthermore, the common electrode 11, the individual electrodes 13, and the connection wiring 33 are covered by the protective film 37, except for the portions connected to the driving IC 31 or the connector 25 (i.e., almost the entirety).

[0055] Durable film 39 is made of, for example, SiN, SiO, SiON, SiC, SiCN, or diamond-like carbon. Durable film 39 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, the IC hard coat 43, and the connector hard coat 45 are each made of an appropriate type of resin. The IC hard coat 43 covers (seals) the driving IC 31. The connector hard coat 45 covers the connector 25 except for a 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-mentioned laminated structure is merely an example and may be modified as appropriate. For example, a base layer may be provided covering the entire upper surface 7a of the substrate 7 from above the glaze layer 35. In other words, a base layer may be provided located between the glaze layer 35 and the conductor layer (the first conductor layer 15 or the second conductor layer 17). This base layer may contribute to reducing the probability that etching of the conductor layer affects a layer below the conductor layer. Also, 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 and latter examples 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 resistivities 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 10.0×10 -8 The electrical resistivity of the second conductor layer 17 may be 1.0×10 -8 Ωm or more 6.0×10 -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 thickness 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 the 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 30 times or less than 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 form, for example, the sub-wiring portion 11d in addition to the main portion 23. Note that a part or the whole of the sub-wiring portion 11d may be formed of the first conductor layer 15 or another conductor layer.

[0065] (4. Specific wiring and surrounding areas) (4.1. Overview of basic patterns) As described above, the specific wiring 21 (FIGS. 4 and 5) connects the multiple leads 19. From another perspective, the specific wiring 21 has bridges 21a that span between adjacent ones of the multiple leads 19.

[0066] In addition, the portion of the lead 19 between adjacent bridges 21a may or may not be regarded as a part of the specific wiring 21. In the description of the embodiment, for convenience, the former or latter way of understanding may be used without special mention. In addition, the term "side edge 21b" may refer to the side edge of the entire specific wiring 21 in some cases, or to the side edge of each bridge 21a in other cases.

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

[0068] 4 and 5, the side edges 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 edges 21b may change its position in the D2 direction in the region overlapping the main portion 23. Examples of such an embodiment include, although not particularly illustrated, an embodiment in which only one of the two side edges 21b changes its position in the D2 direction and the other does not change its position in the D2 direction, and an embodiment in which only one of the two side edges 21b overlaps the main portion 23 and changes its position in the D2 direction, and the other does not overlap the main portion 23.

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

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

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

[0072] In the figures illustrating the specific wiring 21, any of the above aspects may be taken as an example for convenience. However, in each figure, the width of the specific wiring 21 may be different from that shown in the figures. Also, for convenience, the description may be given on the premise that the entire specific wiring 21 overlaps with the main portion 23, as in the examples of Figures 4 and 5, without any particular notice.

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

[0074] In the following, specific examples of the planar shape of the specific wiring 21 and its surrounding area will be described.

[0075] (4.2. Variations of the basic pattern) There are various possible specific aspects of the basic pattern of the specific wiring 21. Figures 6 and 7 are plan views that diagrammatically show specific examples of the basic pattern.

[0076] In the example in the upper part of FIG. 6, the bridge 21a is inclined with respect to the D1 direction. From another point of view, 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 the 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 the inclination angle may change for every one or more predetermined number, or the inclination direction and / or the inclination angle may change randomly. The specific value of the inclination angle is arbitrary, and may be, for example, 45° or more (example of FIG. 4) or less than 45°.

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

[0078] In the example in the lower part of FIG. 6, the positions of adjacent bridges 21a in the D2 direction are different from each other. More specifically, for example, bridges 21a connecting the ends of the leads 19 on the +D2 side (opposite the resistor 9) and bridges 21a connecting the intermediate positions of the leads 19 are alternately arranged in the D1 direction. Unlike the example shown in the figure, a plurality of bridges 21a may be distributed to three or more positions in the D2 direction. In addition, the arrangement mode in this case may be regular or random. The difference in position in the D2 direction (for example, 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, 1 / 2 or more or less than 1 / 2 of the length of overlap with the main portion 23 of the lead 19.

[0079] In the example in the upper part of FIG. 7, the example in the upper part of FIG. 6 and the example in the lower part of FIG. 6 are combined. That is, the bridges 21a extend at an incline with respect to the D1 direction, and the positions of the adjacent bridges 21a in the D2 direction are different from each other. More specifically, two bridges 21a form one straight line, and this one straight line is arranged in the D1 direction. From another point of view, the positions of the ends of the +D2 side of the leads 19 are different for each lead 19 (the lengths are different for each lead), and the bridges 21a connecting the midpoint of the long lead 19 to the ends of the short lead 19 and the bridges 21a connecting the ends of the short lead 19 to the ends of the long lead 19 are arranged alternately in the D1 direction. Unlike the example shown in the figure, the two bridges 21a connected to each other may have different inclination angles. The explanations of the examples in the upper part of FIG. 6 and the lower part of FIG. 6 may be applied to the example in the upper part of FIG. 7, unless a contradiction or the like occurs.

[0080] The example in the middle of Fig. 7 is an example in which the adjacent bridges 21a in the example in the upper part of Fig. 7 are not connected to each other. Specifically, the bridge 21a on the -D2 side is located lower than in the example in the upper part of Fig. 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 of the example in the upper part of Fig. 6, the example in the lower part of Fig. 6, and the example in the upper part of Fig. 7 may be used for the example in the middle part of Fig. 7, unless a contradiction or the like arises.

[0081] The example in the lower part of FIG. 7 is an example in which the bridge 21a in the example in the upper part of FIG. 6 is curved. More specifically, the bridge 21a extends from the middle position 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. This example may be considered as a variation of the example in the middle part of FIG. 6 in that the bridge 21a is curved. Also, this example may be considered as a combination of the example in the upper part of FIG. 6 and the example in the middle part of FIG. 6. The explanations of the example in the upper part of FIG. 6 and the example in the middle part of FIG. 6 may be applied to the example in the lower part of FIG. 7, unless there is a contradiction.

[0082] The above specific examples of the basic patterns may be appropriately combined. For example, although not shown, a configuration in which the bridge 21a is partially or entirely 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 bridge 21a may be curved in the example in the middle part of FIG. 6). Also, a configuration in which the position of the bridge 21a is changed as in the example in the lower part of FIG. 6 may be applied to an example in which the bridge 21a extends while bending as in the example in the middle part of FIG. 6. The inclined bridge 21a as in the example in the upper part of FIG. 6 and the non-inclined bridge 21a as in the example in the lower part of FIG. 6 may be mixed, or the straight bridge 21a as in the examples in the upper and / or lower parts of FIG. 6 and the curved bridge 21a as in the example in the middle part of FIG. 6 may be mixed.

[0083] (4.3.Protrusion) 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 toward the +D2 side (the side opposite to the resistor 9) beyond the specific wiring 21. As shown in Fig. 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 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 therebetween.

[0085] The protrusion 47 can also be regarded as a part of the specific wiring 21 and / or the lead 19. However, in the description of the embodiment, for convenience, an expression is mainly used in which the protrusion 47 is regarded as a part separate 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, the position is the midpoint of the bridge 21a. From yet another perspective, the above position is the apex position on the +D2 side of the curved bridge 21a.

[0087] The shape of the protrusion 47 is arbitrary. In the illustrated example, it is generally linear (rectangular in another view) extending parallel to the D2 direction with a constant width. Unlike the illustrated example, the protrusion 47 may be inclined with respect to the D2 direction, may be thinner or thicker toward the tip side, 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 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. Reticulated 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 has a mesh pattern. In the example in the upper part, the mesh pattern is regular. In the example in the lower part, the mesh pattern is irregular.

[0091] More specifically, the specific wiring 21 in the example in the upper part of Fig. 10 has a plurality of first linear portions 21e1 extending in parallel with each other and a plurality of second linear portions 21e2 extending in parallel with each other (hereinafter, the 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 cross each other to form a net shape. The plurality of linear portions 21e extend with a constant width.

[0092] The first linear portions 21e1 are inclined in a direction that is 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 to the above, and extend in 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 and the same absolute value. This forms a diamond-shaped mesh (non-arrangement area of ​​the first conductor layer 15).

[0093] The specific width of the multiple linear portions 21e is arbitrary, and may be smaller than, equal to, or larger than the width of the lead 19 (as shown in the 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° (as shown in the example). The number of meshes (whose entire circumference is surrounded by linear portions 21e) whose positions in the D2 direction are different from each other is arbitrary, and may be one or more. In the example shown in the figure, there are three.

[0094] Unlike the illustrated example, the inclination angle of the multiple first linear portions 21e1 extending parallel to each other may be different from the inclination angle of the multiple second linear portions 21e2 extending parallel to each other. From another perspective, the mesh may be a parallelogram shape other than a rhombus. Furthermore, three or more linear portions 21e may extend from one lead 19 (see the example in the lower part of FIG. 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 the +D1 side 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 two cross each other to form a net shape.

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

[0097] In the illustrated example, the inclination angles of the multiple 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 a curved portion. The mesh-like specific wiring 21 may have a shape like 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. That is, the mesh-like specific wiring 21 also achieves the effects described in the description of the outline of the embodiment, similar to the basic pattern.

[0100] Also, the examples in the upper and lower parts of Fig. 10 can be considered as those in which a net-like pattern is added to the +D2 side of the multiple bridges 21a shown in the example in the middle part of Fig. 6. From this perspective, the net-like pattern can be considered as a type of basic pattern.

[0101] (4.5. Corners of edges) Fig. 11 is a diagram showing an example of a specific wiring 21 and a corner of its periphery in the first conductor layer 15. The diagram on the right of Fig. 11 corresponds to an enlarged view of region XIa in Fig. 4. The diagram on the left of 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, for example, during manufacture and / or use of the head 1, the likelihood of unintended stress concentration occurring between the first conductor layer 15 and the second conductor layer 17 is reduced. Specifically, the manner in which the corners are curved is as follows.

[0103] The tip edge of the protrusion 47 may be curved (e.g., semicircular) and bulges 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. Also, 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 tip edge and / or the curve of the chamfer is arbitrary. For example, the radius of curvature may be 1 / 2 the width (e.g., maximum width; the same applies below) of the protrusion 47 (in the illustrated example), or 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, 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 D2 direction. 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 (as shown in the example), or forms a corner with a relatively large angle (e.g., 130° or more) with the side edge of the lead 19. 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 corner among 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. Also, the curvature may be such that the bridge 21a becomes thicker rather than narrower.

[0109] As shown in the example on the left of Fig. 11, corners 21m and 21n are curved, which are 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 D2 direction. From another perspective, the two bridges 21a are each thinned. The curve of the corner 21m forms a corner with a relatively large angle (for example, 130° or more) with the straight portion of the side edge 21b. Unlike the example shown in the figure, the curvature may be such that the bridge 21a is thicker.

[0111] Also, at the corners 21n, the corners are curved in such a way that the bridges 21a become thicker. That is, normal chamfering is performed by a curve. Unlike the example shown in the figure, the curvature may be in such a manner that the bridges 21a become thinner.

[0112] Appropriate corners other than the above-mentioned corners may be curved. For example, in the example on the left of Fig. 11, the corner between 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 between 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 1 / 20 or more and 1 / 5 or less of the distance (e.g., the minimum distance) between the side edges of the 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 the bridge 21a is not cut out).

[0114] (4.6. Details of the basic pattern) 12 is a diagram showing another example of the specific shapes and dimensions of the patterns in the upper and middle rows of FIG.

[0115] In the example 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 side edge 21b on the -D2 side are located at approximately the same position in the D2 direction. On the other hand, in the example 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 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, the corner 21m recessed toward the -D2 side formed by the +D2 side edge 21b and the corner 21n 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 in the bottom of Fig. 12, the corner 21m is located closer to the -D2 side than the 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 the bridge 21a is relatively large.

[0117] In the upper and lower examples of FIG. 12, the magnitude of 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 is arbitrary. 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 the aspect in which the corner is notched as illustrated in FIG. 11, the above specific example of the difference d1 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 consideration.

[0118] Unlike the examples of 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 side of Figure 11). In this case, the magnitude of 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 upper and middle patterns in FIG. 6 have been described as examples, the above description of the presence or absence and the magnitude of the difference d1 or difference d2 may be applied to other patterns.

[0120] (4.7. Branching of extension section) FIG. 13 is a diagram showing an example of the configuration of a portion of the comb-tooth portion 11a of the common electrode 11. As shown in FIG.

[0121] It has already been mentioned that the main portion 23 does not have to overlap the entirety of the 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 the difference d1 occurs), so that the portions of the 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, a linear portion 21e parallel to the lead 19 in the direction D2 is added to the specific wiring 21 having a mesh shape (but only one row of mesh) as in the example in the upper part of Fig. 10. The lower edge of the main portion 23 crosses the lead 19 side of the three types of linear portions 21e. This forms three branches 21d branching off from one lead 19. 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 (the specific wiring 21 and the lead 19) that overlaps with the main portion 23, and a portion constituted 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 the lead 19 that does not overlap with the main portion 23. Therefore, the branch 21d may be regarded as a 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 Fig. 13. As long as the branches 21d can be formed, the various patterns exemplified so far (for example, a pattern having a protruding portion 47) may be used.

[0126] The explanations of the basic pattern (particularly the example in the middle of FIG. 6 and examples similar thereto) and the explanation of the net pattern may be applied to examples in which the branches 21d are provided. Thus, for example, the width of the branches 21d is arbitrary. The branches 21d may be straight (the example shown) or curved. The inclination angle of the branches 21d with respect to the D1 direction (or the D2 direction) is arbitrary. The number, shape, inclination angle, etc. of the branches 21d may have regularity (the example shown) or may not have regularity.

[0127] (4.8. Dimensions related to overlap between specific wiring and main part) 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 Fig. 4 and Fig. 5, the specific wiring 21 may be contained within the region on the resistor 9 side when the width W1 of the main portion 23 is divided into two or three equal parts (it does not have to be contained within). In addition, the portion of the first conductor layer 15 (which may include the protruding portion 47) that overlaps with the main portion 23 may be contained within the region on the resistor 9 side when the width W1 of the main portion 23 is divided into two equal parts (it does not have to be contained within).

[0128] As described above, the size of the head body 3 may be various. Furthermore, 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 the linear portion 21e; ​​the same applies below) 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 than the width or length parallel to the D2 direction of the bridge 21a.

[0129] The area of ​​the portion of the first conductor layer 15 overlapping 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 the areas, the areas of the first conductor layer 15 and the main portion 23 may be the area ranging from the end on the +D1 side to the end on the -D1 side of the specific wiring 21, rather than the area of ​​the portion located between the two sub-wiring portions 11d in the D1 direction. In other words, the above area ratio is a value obtained by integrating in the D1 direction the ratio of the length in the D2 direction of the portion of the first conductor layer 15 overlapping 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 be a direction that rotates around the D1 axis. The above-mentioned dimensional ratio (including the area ratio) may be true 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, with respect to the entirety of the two or more surfaces. However, even in such an embodiment, the above-mentioned dimensional ratio may be true when focusing on only a part of the surfaces (for example, the upper surface 7a of the substrate 7).

[0131] (5. Manufacturing method of head body) The head body may be manufactured by various methods, except for the specific pattern of the first conductor layer 15, and may be manufactured by, for example, a known method.

[0132] Specifically, for example, each layer may be formed on the surface of the substrate 7 by an appropriate film formation technique. Film formation methods include, for example, chemical vapor deposition (CVD), physical vapor deposition (PVD), and printing. CVD includes, for example, thermal CVD and plasma CVD. PVD includes, for example, sputtering and ion plating. Printing includes, for example, 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, a recess is formed on the surface of a plate, a material (e.g., conductive paste) that will become the first conductor layer 15 is placed on the surface having the recess, and unnecessary conductive paste is scraped off from the surface by a doctor blade. The material is then transferred from the plate to a blanket, and then transferred 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., conductive paste) to be 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. Printers) Fig. 14 is a schematic diagram showing the configuration of a printer 101 having a head 1. The configuration of the printer 101 may be various configurations, for example, a known configuration, except for the configuration related to the configuration of the head 1 (more specifically, the specific wiring 21 and its peripheral portion). The configuration shown in Fig. 14 is merely one example.

[0136] In addition to the head 1, the printer 101 may include the following components, for example. Conveying device 103: For example, conveys a recording medium P (thermal paper is taken as an example). Platen roller 105: For example, presses the recording medium P against the plurality of heat generating portions 5 (strictly speaking, the durable film 39 covering the plurality of heat generating portions 5). Power supply 107: supplies power to, for example, head 1. Control device 109: For example, controls the head 1, the transport 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 parts 5, a first conductor layer 15, and a second conductor layer 17. The heat generating parts 5 are arranged in a first direction (D1 direction). 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 a specific wiring 21. The multiple leads 19 extend from the multiple heat generating parts 5 in a second direction (D2 direction) intersecting the D1 direction. The specific wiring 21 connects the multiple leads 19 to each other. 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 D2 direction. At least one of the side edge portions 21b on both sides of the specific wiring 21 in the D2 direction 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 point of view, 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 relatively.

[0139] Therefore, as described in the outline 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 probability that the material of the first conductor layer 15 will diffuse 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 exerted. As a result, the difference in current loss between the end and center of the main wiring portion 11b is reduced, and the probability that unintended density unevenness will appear on the recording medium is reduced. In other words, image quality is improved.

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

[0141] In this case, for example, the position where the first conductor layer 15 and the main portion 23 are joined spreads 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 protruding portions 47, an increase in the contact area between the first conductor layer 15 and the main portion 23 is suppressed.

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

[0143] In this case, for example, the likelihood of stress concentrating on the corners during manufacture and / or use of the head 1 is reduced, improving the reliability of the bond between the first conductive layer 15 and the main portion 23. Furthermore, in an embodiment in which the first conductive layer 15 is formed using an intaglio plate, collisions and friction between the doctor blade and the corners of the recesses of the plate are mitigated, 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 recesses at the corners contribute to reducing the area of ​​the specific wiring 21. As a result, for example, the probability that the material of the specific wiring 21 diffuses 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 on the side of the multiple heat generating portions 5 (-D2 side) rather 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 an 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 described above is improved.

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

[0149] In this case, for example, the number of connection paths of the extension 11c (the lead 19 and the part of the specific wiring 21 that is not covered by the main part 23) to the main part 23 is increased. As a result, for example, the wiring resistance of the extension 11c is reduced, and the power consumption of the head 1 is reduced. Also, for example, even if one of the branches 21d is disconnected due to thermal stress or the like generated between the main part 23 and the first conductor layer 15 when the head 1 is being used, the remaining branch 21d maintains the continuity of the extension 11c. Therefore, the corresponding heat generating part 5 does not become completely unable to print, but merely experiences a decrease in print density, for example. As a result, depending on the image quality required 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) (FIGS. 4, the upper and middle parts of FIG. 6, and the upper to lower parts of FIG. 7, etc.).

[0151] In this case, for example, a simple structure of inclining the bridge 21a can change the position of the side edge 21b in the D2 direction. Also, for example, as in the example in the upper part of FIG. 6, it is possible to change the shape of the bridge 21a to a straight line extending with a constant width while changing the position of the side edge 21b in the D2 direction. In this case, for example, compared to a mode in which the bridge 21a is curved (for example, the example in the middle part of FIG. 6), it is easy to change the position of the side edge 21b in the D2 direction even when the gap between the leads 19 is small. Also, for example, when a virtual straight line (not shown) parallel to the D1 direction is assumed, the virtual straight line crosses the side edge 21b of the bridge 21a (for example, in the example in the lower part of FIG. 6, the virtual straight line does not cross the side edge 21b). Therefore, for example, when an intaglio plate is used, a doctor blade parallel to the D1 direction is unlikely to enter a recess corresponding to the bridge 21a.

[0152] Each of the multiple bridges 21a may be curved (eg, FIG. 5, the middle part of FIG. 6, and the lower part of FIG. 7).

[0153] In this case, for example, a simple structure in which the bridge 21a is bent can realize a change in the position of the side edge 21b in the D2 direction. Also, for example, as in the example in the middle part of FIG. 6, it is possible to make the shape of the bridge 21a symmetrical while realizing a change in the position of the side edge 21b in the D2 direction (for example, in the example in the upper part of FIG. 6, the bridge 21a is not symmetrical). This makes it possible, for example, to equalize the mechanical or electrical influence that each bridge 21a imparts to the leads 19 on both sides. As a result, the probability of unintended shape errors or electrical errors occurring is reduced. Also, as in the case where the bridge 21a is inclined, a virtual straight line (not shown) parallel to the D1 direction crosses the side edge 21b, so that the doctor blade parallel to the D1 direction is unlikely to enter the recess corresponding to the bridge 21a.

[0154] Among the multiple bridges 21a, adjacent bridges 21a may be located at different positions in the second direction (direction D2) (eg, 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 are connected at the shortest distance, and the area of ​​bridge 21a is minimized while the position of specific wiring 21 in the D2 direction can be changed. Also, for example, as in the examples in the upper and middle parts of Fig. 7, by tilting (or bending) bridge 21a and making the positions of adjacent bridges 21a different, the arrangement range of specific wiring 21 in the D2 direction can be expanded, and the reliability of the bond between first conductor layer 15 and main portion 23 can be improved. In any case, the bond area can be reduced while the reliability of the bond can be improved.

[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 parts of Figure 12).

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

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

[0159] In this case, for example, assuming a virtual line (not shown) parallel to the D1 direction passing through the position on the -D2 side of the specific wiring 21 and a virtual 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 virtual lines becomes more uniform compared to the basic pattern (FIG. 6, etc.). As a result, the reliability of the connection between the first conductor layer 15 and the main portion 23 is improved uniformly in the above region.

[0160] The area where the first conductor layer 15 overlaps with 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 degree. As a result, the above-mentioned effects are more likely to be achieved.

[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 handy printer that is held and moved by a user and moves relative to the recording medium. The recording device may be one that moves the head relative to the recording medium 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 the surface. Also, in an embodiment where 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, an invention may be extracted that does not require the side edge of the specific wiring to change position in the second direction. For example, an invention may be extracted in which the first conductor layer has a protruding portion that protrudes further from the specific wiring toward the opposite side to the heat generating portion. Also, for example, an invention may be extracted in which a part or all of the specific wiring is mesh-shaped. [Explanation of symbols]

[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 plurality of heat generating portions arranged in a first direction; a first conductor layer; a second conductor layer having a lower electrical resistivity than the first conductor layer; It has The first conductor layer is 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, the second conductor layer has a main portion covering at least a part 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 in the second direction of the specific wiring changes position in the second direction depending on the position in the first direction in a region overlapping the main portion. Thermal head.

2. The first conductor layer has a plurality of protruding portions that protrude from the specific wiring to the opposite side of the plurality of heat generating portions and are covered by the main portion. The thermal head according to claim 1 .

3. The corners of the outer edge of the first conductor layer are curved in a region overlapping the main portion. The thermal head according to claim 1 .

4. The corner is curved in a concave shape, so that the specific wiring becomes thinner at the corner. The thermal head according to claim 3 .

5. The specific wiring is located closer to the plurality of heat generating portions than the center of the main portion in the second direction. The thermal head according to claim 1 .

6. The specific wiring has two or more branches branching from each of the plurality of leads and reaching the main portion. The thermal head according to claim 1 .

7. the specific wiring has a plurality of bridges each spanning adjacent ones of the plurality of leads, Each of the plurality of bridges is inclined with respect to the first direction. The thermal head according to claim 1 .

8. the specific wiring has a plurality of bridges each spanning adjacent ones of the plurality of leads, Each of the plurality of bridges is curved. The thermal head according to claim 1 .

9. the specific wiring has a plurality of bridges each spanning adjacent ones of the plurality of leads, Among the plurality of bridges, adjacent bridges are positioned differently in the second direction. The thermal head according to claim 1 .

10. the specific wiring has a plurality of bridges each spanning adjacent ones of the plurality of leads, The bridges are configured such that the deepest portion of a recess formed by a side edge portion on a first side in the second direction is located closer to the second side than the deepest portion of a recess formed by a side edge portion on a second side in the second direction. The thermal head according to claim 1 .

11. The specific wiring is in a mesh form. The thermal head according to claim 1 .

12. The area where the first conductor layer overlaps with the main portion is 80% or less of the area of ​​the main portion. The thermal head according to claim 1 .

13. A thermal head according to any one of claims 1 to 12; a moving unit that moves the thermal head and the recording medium relative to each other; A recording device having:

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