Thermal head and recording device

Abstract

To provide a thermal print head which has high reliability and is inexpensive.SOLUTION: A thermal head has a glaze, a plurality of heat generation parts, a first conductor layer, and a second conductor layer. The glaze extends in a first direction, and the plurality of heat generation parts overlaps the glaze, and is arrayed in the first direction. The first conductor layer has a plurality of leads, and specific wiring. The plurality of leads extends to a first side in a second direction crossing the first direction from the plurality of heat generation parts, and the part on the second side opposite to the first side overlaps the glaze. The specific wiring is positioned to a side closer to the first side than the glaze, and connects the plurality of leads each other. The second conductor layer has a main part overlapping at least a part of the specific wiring. The specific wiring overlaps a part of the length in the second direction of the main part. At least one of the side edge part on both ends in the second direction of the specific wiring changes the position in the second direction according to the position in the first direction, in a region overlapping the main part.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[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 a plurality of heat generating portions that are subjected to the above-described heating. The plurality of heat generating portions are arranged in a direction orthogonal 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 portions. The common electrode includes a portion extending along the arrangement of the plurality of heat generating portions and is connected to the plurality of heat generating portions. The plurality of individual electrodes are individually connected to the plurality of heat generating portions. By individually controlling the potential applied to the plurality of individual electrodes, the temperatures of the plurality of heat generating portions are individually controlled, and thus, an arbitrary image is formed on the recording medium. In the thermal head of Patent Document 1, a conductor pattern of gold (Au) and a conductor pattern of silver (Ag) are used in combination.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] A thermal head according to one aspect of the present disclosure includes a glaze, a plurality of heat generating portions, a first conductor layer, and a second conductor layer. The glaze extends in a first direction. The plurality of heat generating portions overlap the glaze and are arranged in the first direction. The first conductor layer includes a plurality of leads and a specific wiring. The plurality of leads extend from the plurality of heat generating portions to a first side in a second direction intersecting the first direction, and a portion on a second side opposite to the first side overlaps the glaze. The specific wiring is located on the first side with respect to the glaze and connects the plurality of leads to each other. The second conductor layer has a main portion overlapping at least a part of the specific wiring. The specific wiring overlaps a part of the length of the main portion in the second direction. At least one of the lateral edge portions on both sides of the specific wiring in the second direction changes its position in the second direction according to the position in the first direction in the region overlapping the main portion.

[0006] A recording apparatus according to one aspect of the present disclosure includes the above thermal head and a moving unit that relatively moves the thermal head and a recording medium.

Brief Description of Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Mode for Carrying Out the Invention

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

[0009] For convenience, an orthogonal coordinate system D1D2D3 is attached to the drawings, and terms such as the D1 direction, the D2 direction, and the D3 direction may be used. The D1 direction is an example of the first direction, and the D2 direction is an example of the second direction. As can be understood from the description below, the term in the D1 direction may be replaced with a term in a direction orthogonal to the longitudinal direction of the head, the arrangement direction of the plurality of heat generating portions, and / or the relative movement direction between the head and the recording medium. The term in the D2 direction may be replaced with a term in the short side direction of the head, a direction orthogonal to the above arrangement direction, and / or the above relative movement direction. The term in the D3 direction may be replaced with a term in the normal direction of the head body. The thermal head and the recording device according to the embodiment may be used in any orientation. However, for convenience, terms assuming the + D3 side as the upper side may be used.

[0010] (Overview of Embodiment) FIG. 1 is a schematic exploded perspective view of a thermal head 1 (hereinafter sometimes simply referred to as "head 1") according to an embodiment. The head 1 has a head body 3 that directly performs recording (for example, printing) on a recording medium (for example, paper). Note that the head body 3 may be regarded as an example of a thermal head.

[0011] The head body 3 has a plurality of heating elements 5 arranged in the D1 direction. With the thermal paper sliding in the D2 direction with respect to the plurality of heating elements 5, arbitrary images are formed on the thermal paper by individually controlling the temperatures of the plurality of heating elements 5. Alternatively, with the ink ribbon sliding in the D2 direction with respect to the plurality of heating elements 5, arbitrary images are formed on a recording medium (for example, paper) that moves together with the ink ribbon on the plurality of heating elements 5 by individually controlling the temperatures of the plurality of heating elements 5.

[0012] Note that, as will be understood from the description below, the plurality of heating elements 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 heating elements 5 may be prevented from directly sliding on the thermal paper or the ink ribbon. However, for the sake of convenience, it may be expressed as if the plurality of heating elements 5 are exposed to the outside as described above. Also, in FIG. 1, for the sake of convenience, the plurality of heating elements 5 are shown by solid lines.

[0013] FIG. 2 is a plan view of the head body 3. However, in FIG. 2, some 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. Among the resistors 9, the portions to which voltages are applied by the common electrode 11 and the plurality of individual electrodes 13 constitute the plurality of heating elements 5.

[0015] Note that, as will be understood from the description below, the resistor 9, the common electrode 11, and the individual electrodes 13 do not necessarily overlap directly on the surface of the substrate 7. However, in the description of the embodiments, for the sake of convenience, there may be an expression that ignores the existence of the layer intervening between these components and the substrate 7.

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

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

[0018] FIG. 4 is an enlarged view of region IV in FIG. 2. For the sake of convenience, dot hatching is applied to the surface (i.e., the non-sectional surface) of the first conductor layer 15 described later. FIG. 5 is a diagram showing an example different from FIG. 4 regarding the configuration in region IV.

[0019] The comb teeth portions 11a are constituted by the first conductor layer 15 and the 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 the plurality of heat generating portions 5, and a 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 part of the specific wiring 21 (in the illustrated example, all of the specific wiring 21 and a part of the plurality of leads 19 on the specific wiring 21 side).

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

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

[0023] On the other hand, for example, by using a material with a low probability of diffusing into the resistor 9 as the first conductor layer 15, the probability of deterioration of the characteristics of the plurality of heat generating portions 5 can be reduced. Also, for example, since the first conductor layer 15 and the second conductor layer 17 overlap, the reliability of the connection between the two can be improved.

[0024] Here, the specific wiring 21 overlaps a part of the length (width W1) of the main portion 23 in the D2 direction. 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 lateral edge portions 21b on both sides of the specific wiring 21 in the D2 direction changes its position in the D2 direction according to the position in the D1 direction in the region overlapping the main portion 23.

[0025] In this case, for example, compared with the aspect in which the specific wiring 21 has the same shape and dimensions as the main portion 23, the overlapping area between the specific wiring 21 and the main portion 23 is reduced. Thereby, for example, the probability of mutual diffusion between the material of the first conductor layer 15 and the material of the second conductor layer 17 is reduced. Consequently, the probability that the electrical resistance of the main portion 23 increases due to the diffusion of the material of the first conductor layer 15 is reduced.

[0026] Then, by causing the main portion 23 to exhibit the action of allowing current to flow with low electrical resistance, the difference in current loss between the end portion and the center of the main wiring portion 11b is reduced. As a result, in the plurality of heat generating portions 5, the probability of occurrence of unintended temperature variations is reduced. Consequently, in the recording medium, the probability of occurrence of unintended density unevenness is reduced. That is, the image quality is improved.

[0027] On the other hand, since the specific wiring 21 changes the position in the D2 direction of the side edge portion 21b, the range of the position where the specific wiring 21 and the main portion 23 are joined expands in the D2 direction as compared with the mode in which the specific wiring 21 extends linearly in the D1 direction. For example, when assuming a virtual straight line (not shown) parallel to the D1 direction passing through the most -D2 side position of the specific wiring 21 and a virtual straight line (not shown) parallel to the D1 direction passing through the most +D2 side position of the specific wiring 21, the region sandwiched by the two virtual straight lines becomes wider. As a result, for example, the reliability of the joining of both is improved.

[0028] The above is the outline of the head 1 according to the embodiment. Hereinafter, the head 1 will be described generally in the following order. 1. Overall configuration of the head (FIG. 1) 2. Head 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 the surrounding portions 4.1. Outline of the basic pattern (FIGS. 4 and 5) 4.2. Variations of the basic pattern (FIGS. 6 and 7) 4.3. Protruding portion (FIGS. 8 and 9) 4.4. Mesh pattern (FIG. 10) 4.5. Corner portion of the outer edge (FIG. 11) 4.6. Details of the basic pattern (FIG. 12) 4.7. Branching of the extending portion (FIG. 13) 4.8. Dimensions related to the overlap between the specific wiring and the main portion 5. Manufacturing method of the head body 6. Printer (FIG. 14) 7. Summary of Embodiments

[0029] (1. Overall Configuration of Head) The head 1 may have various configurations except for the configuration of the specific wiring 21 and its peripheral parts, and for example, it may have a known configuration. Hereinafter, while taking the configuration of the illustrated head 1 as an example, the overall configuration of the head 1 will be briefly described.

[0030] As shown in FIG. 1, in addition to the head main body 3, the head 1 may include the following components. · Connector 25: For example, electrically connect the head main body 3 to an external device (for example, the power supply device 107 and the control device 109 shown in FIG. 14 described later). · Heat sink 27: For example, absorb and release unnecessary heat from the head main body 3. · Adhesive member 29: For example, bond the lower surface of the head main body 3 and the heat sink 27.

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

[0032] (2. Head Main Body) In this section, except for the specific configuration related to the specific wiring 21 and its peripheral parts in the head main body 3, an explanation will be given.

[0033] (2.1. General) The head main body 3 may have various configurations except for the configuration related to the specific wiring 21 and its peripheral parts, and for example, it may have a known configuration. The configurations shown in FIGS. 1 and 2 are merely examples.

[0034] For example, in the examples of FIGS. 1 and 2, the plurality of heat generating portions 5 are located on the upper surface 7a of the substrate 7. Different from the illustrated example, the plurality of heat generating portions 5 may be located on the side surface of the substrate 7 (for example, the surface facing the +D2 side), or may be located on an inclined surface obtained by chamfering the corner portion between the upper surface 7a and the side surface. Similarly, all or part of the comb teeth portions 11a of the common electrode 11 and the portions connected to the plurality of heat generating portions 5 of the plurality of individual electrodes 13 may be located on the side surface or the inclined surface instead of on the upper surface 7a. In the comb teeth portion 11a, the portion on at least the opposite side of the extension portion 11c of the main wiring portion 11b and the portion on at least the opposite side of the main wiring portion 11b of the extension portion 11c may be located on different surfaces from each other.

[0035] Also, for example, in the examples of FIGS. 1 and 2, as described above, the plurality of extension portions 11c and the plurality of individual electrodes 13 are alternately arranged in the D1 direction. Different from 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 D2 direction 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 D1 direction. And, among the resistor 9, the portion 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 (the illustrated example) or from above.

[0036] Also, for example, different from the illustrated example, the head body 3 may have a plurality of auxiliary heat generating portions that auxiliary heat the recording medium before the recording medium reaches the plurality of heat generating portions 5. Application of a voltage to such an auxiliary heat generating portion may be constituted by, for example, the plurality of individual electrodes 13, a plurality of common electrodes (different 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 aspect, in addition to the shape of the illustrated example, the individual electrode 13 may have a portion that folds back from the shape to the -D2 side and reaches the auxiliary heat generating portion. Also, one auxiliary heat generating portion extending in the D1 direction may be provided.

[0037] Also, for example, the size of the head body 3 is arbitrary. From another perspective, the size of the recording medium is arbitrary. For example, the paper as the recording medium may be as small as a receipt, may be the size commonly used in the office, or may be as large as a poster. As 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 plurality of heat generating parts 5 coincides with the longitudinal direction of the head body 3, but the two may be in directions orthogonal to each other.

[0038] (2.2. Substrate, Resistor, Common Electrode, and Individual Electrode) As understood from the above, the configurations of the substrate 7, resistor 9, common electrode 11, and individual electrode 13 may be various. Hereinafter, mainly, the configuration illustrated in FIG. 2 will be described.

[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. The shape of the substrate 7 is generally plate-shaped with the D3 direction as the thickness direction, and its shape in plan view is a rectangle having a long side extending in the D1 direction and a short side extending in the D2 direction.

[0040] The resistor 9 is composed of a material having a relatively high electrical resistivity and generates Joule heat when a voltage is applied. Examples of the material of the resistor 9 include those of TaN-based, TaSiO-based, TaSiNO-based, TiSiO-based, TiSiCO-based, NbSiO-based, or RuO2-based. The resistor 9 extends parallel to the long side at a position close to one of the two long sides of the substrate 7, for example. The width of the resistor 9 is constant, for example. 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) or a linear shape that bulges outward.

[0041] The common electrode 11 is, for example, entirely located on the upper surface 7a of the substrate 7. Also, the common electrode 11 has, for example, the aforementioned comb-like portion 11a and a sub-wiring portion 11d for connecting the comb-like portion 11a and the connector 25. Different from the illustrated example, for example, the common electrode 11 may extend over 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 unnecessary.

[0042] The main wiring portion 11b of the comb-like portion 11a extends in a straight line parallel to the D1 direction with a constant width. Different from the illustrated example, for example, the width of the main wiring portion 11b may change according to the position in the D1 direction. Also, as understood from the above description regarding the common electrode 11, the main wiring portion 11b may extend over other surfaces of the substrate 7. The description regarding 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 and as long as there are no contradictions.

[0043] The plurality of extending portions 11c of the comb-like portion 11a have, for example, the same configuration as each other and are arranged at a constant pitch in the D1 direction. Each extending portion 11c extends in a straight line parallel to the D2 direction from the main wiring portion 11b toward the resistor 9 and crosses the entire width of the resistor 9 in plan view. For the extending portion 11c, for example, the portion crossing the resistor 9 may have a narrower width than the portion on the side of the main wiring portion 11b (see FIGS. 4 and 5), or may have a constant width over the entire length. The description regarding the planar shape of the extending portion 11c may be applied to the planar shape of the lead 19 of the first conductor layer 15 unless otherwise specified and as long as there are no contradictions.

[0044] The plurality of individual electrodes 13 extend, for example, from the side opposite to the main wiring portion 11b of the common electrode 11 toward the resistor 9 with respect to the resistor 9, and cross the entire width of the resistor 9. The plurality of individual electrodes 13 have, for example, the same configuration in the portion crossing the resistor 9 (the end portion on the resistor 9 side), and the crossing portions are arranged at a constant pitch in the D1 direction. Among the plurality of individual electrodes 13, the portion opposite to the resistor 9 extends toward a driving IC (Integrated Circuit) described later. The shape of this portion is arbitrary.

[0045] As described above, at least the portion of the main wiring portion 11b opposite to the extending portion 11c and at least the portion of the extending 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 on the lower surface of the substrate 7. As can be understood from such examples, the second direction intersecting the arrangement direction (first direction) of the plurality of heat generating portions 5 may be widely interpreted. That is, the second direction does not have to be a linear direction, and may be a circumferential direction that goes 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 conceptually defined with the length in the second direction as the width (in other words, a shape that cannot be conceptually defined as extending in the first direction). However, in the description of the embodiment, for convenience, there may be expressions based on the illustrated examples without particular notice.

[0046] (2.3. Other components) As shown in FIG. 2, the head body 3 may have, for example, 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 plurality of individual electrodes 13. Note that the driving IC 31 may be regarded as not being a component of the head body 3. · A plurality of connection wirings 33: For example, connect the driving IC 31 and the connector 25.

[0047] The drive IC 31 is mounted on the substrate 7, generates a drive signal according to the signal input from the connector 25 via the connection wiring 33, and inputs it to the plurality of individual electrodes 13. The plurality of connection wirings 33 are constituted by a conductor layer located on the surface of the substrate 7. The shape and the like of the plurality of connection wirings 33 are arbitrary. Although not particularly shown, a wiring (conductor layer) for connecting the drive ICs 31 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. 2.

[0049] As shown in this figure, in addition to the above-described substrate 7, the first conductor layer 15, and the second conductor layer 17, the head body 3 may have, for example, the following components. · Heating part glaze 35a: For example, it contributes to heat storage under the heating part 5. · Wiring part glaze 35b: For example, a surface with fewer irregularities than the surface of the substrate 7 is formed on the substrate 7 (under the wiring). · Protective film 37: For example, it insulates electrodes, wirings, and resistors. · Durable film 39: For example, it improves the durability of the head body 3 against the sliding of the recording medium. · Protective resin 41: For example, it improves the printability of the following hard coats (43 and 45). · IC hard coat 43: For example, it protects the drive IC 31. · Connector hard coat 45: For example, it strengthens the bonding of the connector 25 to the head body 3.

[0050] The heating part glaze 35a is formed, for example, in a curved shape (for example, an arc shape) or a linear shape in which the upper surface bulges outward in a cross section, and extends in the D1 direction with a cross section of a certain shape and dimensions. The portion of the extension part 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 heating part glaze 35a.

[0051] The wiring part glaze 35b extends over substantially the entire upper surface 7a of the substrate 7 at a position separated from the heat generating part glaze 35a by a certain distance toward the -D2 side. The -D2 side portion of the sub-wiring part 11d, the -D2 side portion of the individual electrode 13, and the connection wiring 33 overlap the upper surface of the wiring part glaze 35b.

[0052] In non-arrangement positions of the heat generating part glaze 35a and the wiring part glaze 35b, the first conductor layer 15 and the second conductor layer 17 directly overlap, for example, the upper surface 7a of the substrate 7. Such portions include the specific wiring 21 (for example, all of it), the main part 23 (for example, all of it), the middle part of the extending part 11c, the middle part of the sub-wiring part 11d, and the middle part of the individual electrode 13.

[0053] The heat generating part glaze 35a and the wiring part glaze 35b are made of glass. These as a whole may be regarded as the glaze layer 35. Different from 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 substantially the entire upper surface 7a of the substrate 7, excluding, for example, the arrangement regions of the drive IC 31 and the connector 25. Consequently, the common electrode 11, the plurality of individual electrodes 13, and the connection wiring 33 are covered with the protective film 37, excluding the portions connected to the drive IC 31 or the connector 25 (that is, substantially the whole).

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

[0056] The protective resin 41, the IC hard coat 43, and the connector hard coat 45 are each composed of an appropriate type of resin. The IC hard coat 43 covers (seals) the drive IC 31. The connector hard coat 45 covers the connector 25 except for the terminal portion for externally connecting the connector 25. The protective resin 41 covers substantially the entire wiring portion glaze 35b from above while avoiding the region where the above hard coats are disposed.

[0057] The above-described laminated structure is merely an example and may be appropriately changed. For example, an underlayer may be provided that covers the entire upper surface 7a of the substrate 7 from above the glaze layer 35. In other words, an underlayer may be provided between the glaze layer 35 and the conductor layer (the first conductor layer 15 or the second conductor layer 17). This underlayer may contribute, for example, to reducing the probability that etching of the conductor layer acts on 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 Conductor Layer and Second Conductor Layer) The material of the first conductor layer 15 and the material of the second conductor layer 17 are arbitrary as long as the electrical resistivity of the latter is lower than that of the former. There are innumerable such combinations of 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 arbitrarily combined, and for example, a combination of Au and Ag may be adopted.

[0060] Note that 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 mass%.

[0061] The specific value of the electrical resistivity and the specific degree of difference in the electrical resistivity between 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 may be -8 2.0×10 -8 Ωm or more and 10.0×10 -8 Ωm or less. The electrical resistivity of the second conductor layer 17 may be 1.0×10 -8 Ωm or more and 6.0×10 -8 Ωm or less (however, it is 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 are arbitrary, and the difference between the two is also arbitrary. For example, the thickness of the second conductor layer 17 may be made thicker than the thickness of the first conductor layer 15. Thereby, the effect of reducing the electrical resistance by the second conductor layer 17 is improved. 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 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] In addition to the lead 19 and the specific wiring 21, the first conductor layer 15 may constitute, for example, the individual electrodes 13 and the connection wiring 33. Note that a part of the individual electrodes 13 on the side of the driving IC 31, a part or all of the connection wiring 33 may be constituted by the second conductor layer 17 or another conductor layer.

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

[0065] (4. Specific Wiring and the Surrounding Parts) (4.1. Outline of the Basic Pattern) The specific wiring 21 (Figs. 4 and 5) connects a plurality of leads 19 as described above. From another perspective, the specific wiring 21 has bridges 21a that span between adjacent ones of the plurality of leads 19 respectively.

[0066] Note that the portion between adjacent bridges 21a among the leads 19 may or may not be regarded as part of the specific wiring 21. In the description of the embodiment, for convenience, without particular notice, there may be expressions that regard it in the former or latter way. Also, the term "lateral edge portion 21b" may refer to the lateral edge portion of the entire specific wiring 21 or the lateral edge portion of each bridge 21a.

[0067] In the examples of Figs. 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 reciprocating 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 Fig. 10) will be described later. However, as will also be described later, the pattern of Fig. 10 can also be regarded as a kind of basic pattern.

[0068] In the examples of Figs. 4 and 5, the lateral edge portions 21b on both sides of the specific wiring 21 change their positions in the D2 direction according to the position in the D1 direction in the region overlapping the main portion 23 of the second conductor layer 17. Different from the illustrated example, only one of the lateral edge portions 21b may change its position in the D2 direction in the region overlapping the main portion 23. Examples of such a mode include, although not particularly illustrated, a mode in which only one of the two lateral edge portions 21b changes its position in the D2 direction and the other does not, and a mode in which only one of the two lateral 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] In the examples of FIGS. 4 and 5, the entire specific wiring 21 overlaps the main part 23. However, as also mentioned above, only a part of the specific wiring 21 may overlap the main part 23 (see also FIG. 13 described later). Assuming that the edge on the -D2 side of the main part 23 is a straight line parallel to the D1 direction, an example of such a mode will be given.

[0070] For example, in FIG. 4, the edge on the -D2 side of the main part 23 may intersect 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 the side edge 21b on the +D2 side. As can be understood from FIG. 13 described later, depending on the specific mode of the specific wiring 21, the edge on the -D2 side of the main part 23 may also intersect both the side edge 21b on the -D2 side and the side edge 21b on the +D2 side.

[0071] Also, for example, in FIG. 5, the edge on the -D2 side of the main part 23 may intersect the side edge 21b on the -D2 side or may intersect the side edge 21b on the +D2 side. Depending on the specific mode of the specific wiring 21, the edge on the -D2 side of the main part 23 may also be located between the side edge 21b on the -D2 side and the side edge 21b on the +D2 side or may intersect both of them.

[0072] In the figures illustrating the specific wiring 21, for the sake of convenience, any of the above modes may be taken as an example. However, in each figure, the width of the specific wiring 21 may be different from that shown. Also, for the sake of convenience, without particular notice, there may be an explanation on the premise that the entire specific wiring 21 overlaps the main part 23 as in the examples of FIGS. 4 and 5.

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

[0074] Hereinafter, specific examples of the planar shape of the specific wiring 21 and its peripheral portion will be described.

[0075] (4.2. Variations of the basic pattern) Various specific embodiments of the basic pattern of the specific wiring 21 are possible. FIGS. 6 and 7 are plan views schematically showing specific examples of the basic pattern.

[0076] In the upper example of FIG. 6, the bridge 21a is inclined with respect to the D1 direction. From another viewpoint, the positions of both ends of the bridge 21a in the D2 direction are different from each other. The directions of inclination (- on which side of the -D1 side end is the +D1 side end located, either on the -D2 side or the +D2 side) and the inclination angles of the plurality of bridges 21a are, for example, the same as each other. Different from the illustrated example, the direction of inclination and / or the inclination angle may change every one or more predetermined numbers, or the direction of inclination and / or the inclination angle may change randomly. The specific value of the inclination angle is arbitrary, and for example, it may be 45° or more (the example of FIG. 4), or it may be less than 45°.

[0077] In the middle example of FIG. 6, the bridge 21a extends while bending. The specific modes (directions and angles, etc.) in which the plurality of bridges 21a bend are, for example, the same as each other. In the illustrated example, the bridge 21a has one bent portion where two linear portions intersect so as to come closer to the +D2 side (opposite side to the resistor 9) and then return. Different from the illustrated example, it may come closer to the -D2 side and then return, or may extend in a curved shape as a whole and have one curved portion, or may extend in a zigzag manner and have two or more bent portions (bent portions and / or curved portions). Also, the mode of the bent portion may change every one or more predetermined numbers, or the mode of the bent portion may change randomly. The specific value of the angle of the bent portion is arbitrary, and for example, it may be 90° or more, or it may be less than 90° (the example of FIG. 5).

[0078] In the example in the lower part of FIG. 6, the adjacent bridges 21a have different positions in the D2 direction. More specifically, for example, the bridges 21a connecting the ends on the +D2 side (opposite to the resistor 9) of the lead 19 and the bridges 21a connecting the intermediate positions of the lead 19 are alternately arranged in the D1 direction. Different from the illustrated example, a plurality of bridges 21a may be distributed at three or more positions in the D2 direction. Also, the arrangement pattern at this time may be regular or random. The difference in position in the D2 direction (for example, the distance between the centers of the one located on the most +D2 side and the one located on the most -D2 side) is arbitrary. For example, it may be 1 / 2 or more, or less than 1 / 2, with respect to the length overlapping the main part 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 plurality of bridges 21a extend obliquely with respect to the D1 direction, and the adjacent bridges 21a have different positions in the D2 direction from each other. More specifically, one straight line is formed by two bridges 21a, and this one straight line is arranged in the D1 direction. From another perspective, the positions of the ends on the +D2 side of each lead 19 are different (the lengths of each lead 19 are different), and the bridges 21a connecting the intermediate position of the long lead 19 and the end of the short lead 19 and the bridges 21a connecting the end of the short lead 19 and the end of the long lead 19 are alternately arranged in the D1 direction. Different from the illustrated example, the two bridges 21a connected to each other may have different inclination angles. The descriptions of the example in the upper part of FIG. 6 and the example in the lower part of FIG. 6 may be applied to the example in the upper part of FIG. 7 as long as there is no contradiction or the like.

[0080] The example in the middle section of FIG. 7 is obtained by preventing adjacent bridges 21a from being connected to each other in the example in the upper section of FIG. 7. Specifically, the bridge 21a on the -D2 side is located lower than in the example in the upper section of FIG. 7. From another perspective, the bridge 21a on the -D2 side connects the mid-position of the long lead 19 and the mid-position of the short lead 19. The descriptions of the examples in the upper section of FIG. 6, the example in the lower section of FIG. 6, and the example in the upper section of FIG. 7 may be applied to the example in the middle section of FIG. 7 as long as there are no contradictions.

[0081] The example in the lower section of FIG. 7 is obtained by curving the bridge 21a in the example in the upper section of FIG. 6. More specifically, the bridge 21a extends approximately parallel to the D1 direction from the mid-position of the lead 19 toward the +D1 side, then bends toward the +D2 side, and then extends approximately parallel to the D1 direction and is connected to the +D2 side end of the adjacent lead 19. This example may be regarded as a variation of the example in the middle section of FIG. 6 from the perspective that the bridge 21a is curved. It may also be regarded as a combination of the example in the upper section of FIG. 6 and the example in the middle section of FIG. 6. The descriptions of the example in the upper section of FIG. 6 and the example in the middle section of FIG. 6 may be applied to the example in the lower section of FIG. 7 as long as there are no contradictions.

[0082] The specific examples of the above basic patterns may be combined as appropriate. For example, although not particularly illustrated, a configuration in which part or all of the bridge 21a is curved as in the example in the lower section of FIG. 7 may be applied to the examples in the upper and middle sections of FIG. 7 (it has already been stated that the bridge 21a may be curved in the example in the middle section of FIG. 6). Also, a configuration in which the position of the bridge 21a is changed as in the example in the lower section of FIG. 6 may be applied to an example in which the bridge 21a extends while curving as in the example in the middle section of FIG. 6. There may be a mixture of a slanted bridge 21a as in the example in the upper section of FIG. 6 and a non-slanted bridge 21a as in the example in the lower section of FIG. 6, or a mixture of a straight bridge 21a as in the upper and / or lower sections of FIG. 6 and a curved bridge 21a as in the example in the middle section of FIG. 6.

[0083] (4.3. Protrusion) Figures 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 Figures 6 and 7.

[0084] As shown in Figures 8 and 9, the first conductor layer 15 may have a protruding portion 47 that protrudes to the +D2 side (opposite side to the resistor 9) from the specific wiring 21. As shown in Figures 4 and 5, all or part of the protruding portion 47 may be 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 spreads to the +D2 side, and the reliability of the joining between the two is improved.

[0085] Note that the protruding portion 47 can also be regarded as part of the specific wiring 21 and / or the lead 19. However, in the description of the embodiment, for convenience, mainly, an expression is used in which the protruding portion 47 is regarded as a part separate from the specific wiring 21 and the lead 19.

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

[0087] The shape of the protruding portion 47 is arbitrary. In the illustrated example, it is schematically linear (rectangular in another perspective) with a constant width and extending parallel to the D2 direction. Different from the illustrated example, the protruding portion 47 may be inclined with respect to the D2 direction, thinner or thicker towards the tip side, and / or bent.

[0088] The protruding amount (in the D2 direction) and width (in the D1 direction) of the protruding portion 47 are arbitrary. For example, the protruding amount may be small, equal to, or larger than the length (in the D2 direction) overlapping with the main portion 23 of the lead 19 and / or the amount of change in the position in the D2 direction of the side edge portion 21b. The width of the protruding portion 47 may be smaller than, 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] In the upper and lower examples of FIG. 10, the specific wiring 21 is in a mesh shape. In the upper example, the pattern of the mesh is regular. In the lower example, the pattern of the mesh is irregular.

[0091] More specifically, the specific wiring 21 in the upper example 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, both may be collectively referred to as the linear portion 21e without distinction). The mesh shape is formed by the plurality of first linear portions 21e1 and the plurality of second linear portions 21e2 intersecting with each other. The plurality of linear portions 21e extend with a constant width.

[0092] The plurality of first linear portions 21e1 are inclined in a direction where they are located more on the +D1 side as they are closer to the +D2 side, and linearly extend parallel to each other from the +D2 side ends of the plurality of leads 19 toward the +D2 side. The plurality of second linear portions 21e2 are inclined in the opposite direction and extend parallel to each other from the +D2 side ends of the plurality of leads 19 toward the +D2 side. The inclination angles of the first linear portion 21e1 and the second linear portion 21e2 with respect to the D2 direction have opposite signs and the same absolute value. Thereby, a rhombus-shaped mesh (non-arrangement region of the first conductor layer 15) is formed.

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

[0094] Different from the illustrated example, the inclination angles of the plurality of first linear portions 21e1 extending parallel to each other and the inclination angles of the plurality of second linear portions 21e2 extending parallel to each other may be different from each other. From another perspective, the mesh may be a parallelogram shape that is not a rhombus shape. Also, 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 located on the +D1 side more toward the +D2 side and a plurality of second linear portions 21e2 that are inclined so as to be located on the -D1 side more toward the +D2 side, similar to the specific wiring 21 in the example in the upper part of FIG. 10. And a mesh shape is formed by their intersection.

[0096] Randomness may be realized by an appropriate method. In the illustrated example, randomness is imparted to the inclination angles of the plurality of linear portions 21e. In addition to those extending from the plurality of leads 19 (their ends), the linear portions 21e that extend starting from an intermediate position of the linear portion 21e are randomly provided. Among the plurality of leads 19, the number of linear portions 21e extending from other parts varies randomly. That is, three types of randomness are imparted. Note that randomness may be realized by only one or two types.

[0097] In the illustrated example, since the inclination angles of the plurality of first linear portions 21e1 are different from each other, the first linear portions 21e1 also intersect each other. The same applies to the second linear portions 21e2. Thus, a mesh is also formed.

[0098] In both the upper and lower examples of FIG. 10, different from the illustrated examples, the linear part 21e may not have a constant width and may also include a curved part. The reticular specific wiring 21 may have a shape such as a punching metal with circular meshes. The positions of the ends of the plurality of leads 19 on the +D2 side in the D2 direction may not be constant.

[0099] In each of the upper and lower examples of FIG. 10, the edge portions on both sides of the specific wiring 21 in the D2 direction constitute two side edge portions 21b, similar to the specific wiring 21 of the basic pattern. It can be considered that the side edge portions 21b change their positions in the D2 direction in the region where any reticular specific wiring 21 overlaps with the main part 23. That is, for the reticular specific wiring 21 as well, the effects described in the description of the outline of the embodiment are achieved, similar to the basic pattern.

[0100] Also, the upper or lower example of FIG. 10 can be considered as adding a reticular pattern to the plurality of bridges 21a shown in the middle example of FIG. 6 on the +D2 side. From such a perspective as well, the reticular can be considered as a kind of basic pattern.

[0101] (4.5. Corners of the edge part) FIG. 11 is a diagram showing an example of the specific wiring 21 and the corners of its peripheral part in the first conductor layer 15. The right diagram of FIG. 11 corresponds to an enlarged view of the region XIa in FIG. 4. The left diagram of FIG. 11 corresponds to an enlarged view of the region XIb in FIG. 5.

[0102] As shown in these diagrams, in the region where the first conductor layer 15 and the second conductor layer 17 (for example, the main part 23) overlap, the corners of the outer edge of the first conductor layer 15 may be curved. In this case, for example, the probability of unintended stress concentration occurring between the first conductor layer 15 and the second conductor layer 17 during the manufacture and / or use of the head 1 is reduced. The mode of the curvature of the corners is specifically as follows.

[0103] The tip edge of the protrusion 47 may be curved outwardly (e.g., semi-circular). From another perspective, the corner between the tip edge of the protrusion 47 (the edge on the +D2 side) and the side edge (the edge on the -D1 side or +D1 side) may be chamfered by a curve. In the illustrated example, it can be understood that the chamfering curve on the -D1 side and the chamfering curve on the +D1 side are smoothly connected.

[0104] Different from the illustrated example, a tip edge parallel to the D1 direction may remain between the chamfering curve on the -D1 side and the chamfering curve on the +D1 side. Also, a corner with a relatively large angle may remain between the curved tip edge and the straight side edge, or at one or both ends of the chamfering 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 chamfering curve is arbitrary. For example, the radius of curvature may be 1 / 2 of the width of the protrusion 47 (e.g., the maximum width; the same applies hereinafter) (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] As shown in the example on the right in FIG. 11, among 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 acute-angled corner 21f is curved. As can be understood from this example, when the corner of the outer edge of the first conductor layer 15 is curved, the above-mentioned corner includes not only the corner where the first conductor layer 15 is convex but also the corner where the first conductor layer 15 is concave.

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

[0108] Unlike the illustrated example, of the two types of corners formed by the lateral edge 21b of the bridge 21a and the lateral edge of the lead 19, the obtuse-angled corner may also be curved. Further, the curvature may be in a shape in which the bridge 21a becomes thicker, rather than in a shape in which the bridge 21a becomes thinner.

[0109] As shown in the left example of FIG. 11, the corners 21m and 21n formed by the lateral edge 21b of the specific wiring 21 being bent are curved. The corner 21m is formed by the adjacent bridges 21a intersecting. The corner 21n is formed by the bent portion of the bridge 21a.

[0110] More specifically, in the corner 21m, the lateral edge 21b is curvedly notched in the D2 direction. From another perspective, the two bridges 21a are each thinned. And the curve of the corner 21m forms a corner with a relatively large angle (for example, 130° or more) with the linear portion of the lateral edge 21b. Unlike the illustrated example, the curvature may be in a manner in which the bridge 21a becomes thicker.

[0111] Also, in the corner 21n, the corner is curved in a shape in which the bridge 21a becomes thicker. That is, chamfering is normally performed by the curve. Unlike the illustrated example, the curvature may be in a manner in which the bridge 21a is thinned.

[0112] Appropriate corners other than the above-described corners may be curved. For example, in the left example of FIG. 11, the corner between the lateral edge 21b on the -D2 side and the lateral 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 lateral edge 21b may be curved.

[0113] The curvatures of the curves at the corners 21f, 21m, and 21n and other corners are arbitrary. For example, the radius of curvature may be 1 / 20 or more and 1 / 5 or less with respect to the distance (e.g., the minimum distance) between the lateral edges of the adjacent leads 19 and / or the length parallel to the D2 direction of the bridge 21a (e.g., the minimum length assuming it is not notched).

[0114] (4.6. Details of the basic pattern) FIG. 12 is a diagram showing another example regarding the specific shape or dimensions of the upper and middle patterns of FIG. 6. In this figure, the arrow a1 indicates the moving direction of the recording medium with respect to the head body 3.

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

[0116] In the example of the middle part of FIG. 6, the corner 21m recessed on the -D2 side formed by the lateral edge 21b on the +D2 side and the +D2 side corner 21n recessed on the +D2 side formed by the lateral edge 21b on the -D2 side are substantially the same in position in the D2 direction. On the other hand, in the example of the lower part of FIG. 12, the corner 21m is located on the -D2 side rather than the corner 21n. From another perspective, in the example of the lower part of FIG. 12, the inclination angles with respect to the D1 direction before and after the bent part of the bridge 21a are relatively large.

[0117] In the examples of the upper and lower portions of FIG. 12, the magnitude of the difference d1 between the corner portions (21f or 21m) recessed on the -D2 side and the corner portions (21f or 21n) recessed on 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 parallel to the D2 direction of the specific wiring 21 (for example, the minimum length when not notched). The upper limit is not particularly limited. As illustrated in FIG. 11, in the aspect where the corner portions are notched, the specific example of the above difference d1 may be applied to the difference d1 when ignoring the notches, or may be applied to the difference d1 when considering the notches.

[0118] Different from the examples of FIGS. 6 and 12, the corner portions (21f or 21m) recessed on the -D2 side may be located on the +D2 side with respect to the corner portions (21f or 21n) recessed on the +D2 side (see the right example in FIG. 11). The magnitude of the difference d2 (FIG. 11) in the D2 direction between the two in this case is also arbitrary. For example, the specific examples of the above difference d1 may be applied to the difference d2.

[0119] Although the patterns of the upper and middle portions of FIG. 6 have been described as examples, the description of the presence or absence and magnitude of the above difference d1 or difference d2 may be applied to other patterns.

[0120] (4.7. Branching of the extension part) FIG. 13 is a diagram showing an example of the configuration of a part of the comb teeth portion 11a of the common electrode 11.

[0121] It has already been described that the main portion 23 does not necessarily overlap the entire specific wiring 21. FIG. 13 illustrates an aspect in which the main portion 23 overlaps only a part of the specific wiring 21. Specifically, an aspect is illustrated in which two or more (two in the upper example and three in the lower example) branches 21d that branch from each lead 19 and reach the main portion 23 are formed by the portion of the specific wiring 21 that is not covered by the main portion 23.

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

[0123] Also, in the lower example of FIG. 13, in a specific wiring 21 in a net shape (however, only one row of meshes) as in the upper example of FIG. 10, a linear portion 21e parallel to the D2 direction is added from the lead 19. And the lower edge of the main portion 23 crosses the portions of the three types of linear portions 21e on the lead 19 side. As a result, three branches 21d branching from one lead 19 are formed. Note that, similar to the reference numeral of the bridge 21a, the specific wiring 21 in the lower example of FIG. 13 can also be regarded as a kind of basic pattern.

[0124] Note that, as described above, the main wiring portion 11b of the comb tooth portion 11a may be defined as a portion where the main portion 23 overlaps in the first conductor layer 15 (specific wiring 21 and lead 19) and a portion formed by the main portion 23. The extending portion 11c of the comb tooth portion 11a may be defined as a portion where the main portion 23 does not overlap in the specific wiring 21 and the lead 19. Therefore, the branch 21d may be regarded as a portion of the extending portion 11c on the side of the main wiring portion 11b.

[0125] The number of branches 21d is arbitrary, and different from the illustrated example, it may be 4 or more. In the aspect where the branch 21d is provided, as understood from the upper and lower examples of FIG. 13, the aspect of the specific wiring 21 may be a basic pattern or a net pattern. As long as the branch 21d can be formed, various patterns exemplified so far (for example, a pattern having a protrusion 47) may be used.

[0126] The description of the basic pattern (especially the example in the middle of FIG. 6 and similar examples) and the description of the mesh pattern may be applicable to the example in which the branch 21d is provided. Therefore, for example, the width of the branch 21d is arbitrary. The branch 21d may be linear (example shown in the figure) or may be curved. The inclination angle of the branch 21d with respect to the D1 direction (or D2 direction) is arbitrary. The number, shape, inclination angle, etc. of the branches 21d may have regularity (example shown in the figure) or may not have regularity.

[0127] (4.8. Dimensions related to the overlap between the specific wiring and the main part) The degree of overlap between the first conductor layer 15 (especially the specific wiring 21) and the main part 23 is arbitrary. For example, as illustrated in FIGS. 4 and 5, the specific wiring 21 may (or may not) fit within the region on the resistor 9 side when the width W1 of the main part 23 is bisected or trisected. Also, the portion of the first conductor layer 15 (which may include the protruding portion 47) that overlaps the main part 23 may (or may not) fit within the region on the resistor 9 side when the width W1 of the main part 23 is bisected.

[0128] As described above, the size of the head body 3 may be various. Consequently, the specific values and their differences of the width (length in the direction perpendicular to the center line) or the length parallel to the D2 direction of the bridge 21a (or the linear part 21e; the same applies hereinafter), and the width W1 of the main part 23 are arbitrary. For example, the width or the length parallel to the D2 direction of the bridge 21a may be set to 5 μm or more and 150 μm or less. The width W1 may be set to 100 μm or more and 1 mm or less on the condition 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 the length parallel to the D2 direction of the bridge 21a.

[0129] Also, the area of the portion of the first conductor layer 15 that overlaps 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 exceed 80%). When comparing these areas, the areas of the first conductor layer 15 and the main portion 23 are not the areas of the portions located between the two sub-wiring portions 11d in the D1 direction, but may be the areas of the ranges from the +D1 side end to the -D1 side end of the specific wiring 21. In other words, the above area ratio is the 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 that overlaps the main portion 23 to the width W1 of the main portion 23.

[0130] As described above, the main portion 23 may extend across 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 circulates around the D1 axis. The above dimensional ratios (including the area ratio) may hold not only for the aspect where the entire main portion 23 is located on one surface, but also for the aspect where the main portion 23 extends across two or more surfaces, with respect to the entirety across the two or more surfaces. However, even in such an aspect, the above dimensional ratios may hold when focusing only on a part of the surfaces (for example, the upper surface 7a of the substrate 7).

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

[0132] Specifically, for example, each layer may be formed on the surface of the substrate 7 by an appropriate film-forming technique. Examples of the film-forming method include CVD (chemical vapor deposition), PVD (physical vapor deposition), 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 may be performed by etching after CVD or PVD.

[0133] More specifically, the first conductor layer 15 may be formed, for example, by gravure offset printing (intaglio offset printing). For example, recesses are formed on the surface of the plate, a material (for example, a conductive paste) that becomes the first conductor layer 15 is disposed on the surface having the recesses, and unnecessary conductive paste is scraped off from the surface by a doctor blade. Thereafter, the material is transferred from the plate to the blanket, and the material is transferred from the blanket to the substrate 7. Thereafter, the conductive paste is fired.

[0134] Also, the second conductor layer 17 may be formed, for example, by screen printing. For example, a material (for example, a conductive paste) that becomes the second conductor layer 17 is disposed on the screen, and the conductive paste is transferred to the substrate 7 by sliding a squeegee on the screen. Thereafter, the conductive paste is fired. Note that the first conductor layer 15 and the second conductor layer 17 may be fired together or may be fired 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 be various configurations except for the configuration related to the configuration of the head 1 (more specifically, the specific wiring 21 and its peripheral part), and may be, for example, a known configuration. The configuration shown in FIG. 14 is merely an example.

[0136] In addition to the head 1, the printer 101 may have, for example, the following components. · Conveying device 103: For example, it conveys a recording medium P (taking thermal paper as an example). · Platen roller 105: For example, it presses the recording medium P against a plurality of heat generating portions 5 (strictly speaking, a durable film 39 covering the plurality of heat generating portions 5). · Power supply device 107: For example, it supplies power to the head 1. · Control device 109: For example, it controls the head 1, the conveying 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 the 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 plurality of leads 19 extend in a second direction (D2 direction) intersecting the D1 direction from the plurality of heat generating portions 5. The specific wiring 21 connects the plurality of leads 19 to each other. The second conductor layer 17 has a main portion 23 covering at least a part of the specific wiring 21. The specific wiring 21 overlaps a part of the length (width W1) of the main portion 23 in the D2 direction. At least one of the lateral edge portions 21b on both sides of the specific wiring 21 in the D2 direction changes its position in the D2 direction according to the position in the D1 direction in the region overlapping the main portion 23.

[0138] From another perspective, the recording device (printer 101) according to the embodiment has the above-mentioned head 1 and a moving portion (conveying device 103) that relatively moves the head 1 and the recording medium.

[0139] Therefore, as described in the summary of the embodiments, while maintaining the reliability of the bonding strength between the specific wiring 21 and the main portion 23, the bonding area between the two can be reduced. By reducing the bonding area, the probability that the material of the first conductor layer 15 diffuses 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 exhibited. As a result, the difference in current loss between the end and the center of the main wiring portion 11b is reduced, and the probability that non-intended density unevenness appears on the recording medium is reduced. That is, the image quality is improved.

[0140] The first conductor layer 15 may have a plurality of protruding portions 47 (FIGS. 4, 5, 8, 9, etc.). The plurality of protruding portions 47 may protrude on the side opposite to the plurality of heat generating portions 5 with respect to the specific wiring 21 (the +D2 side), 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 spreads to the +D2 side, and the reliability of the joining between the two is improved. Since the first conductor layer 15 and the main portion 23 do not overlap between the plurality of protruding portions 47, an increase in the contact area between the first conductor layer 15 and the main portion 23 can be suppressed.

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

[0143] In this case, for example, during the manufacturing and / or use of the head 1, the probability that stress concentrates on the corners is reduced, and the reliability of the joining between the first conductor layer 15 and the main portion 23 is improved. Further, in an aspect where the first conductor layer 15 is formed using a gravure printing plate, the collision and friction between the doctor blade and the corners of the recesses of the plate are alleviated. As a result, the life of the doctor blade and / or the plate is extended.

[0144] Due to the above corners (21f and / or 21m) being curved in a concave shape, the specific wiring 21 may be thinned at the above corners (FIG. 11).

[0145] In this case, for example, the recess at the corner 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 diffuses into the main part 23 is further reduced.

[0146] The specific wiring 21 (or the entire first conductor layer 15 including the protruding portion 47) may be located on the side (-D2 side) of a plurality of heat generating portions 5 rather than the center in the second direction (D2 direction) of the main part 23 (FIGS. 4 and 5).

[0147] In this case, it is easy to secure an area of the main part 23 that 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 part 23, which has been described above, is improved.

[0148] The specific wiring 21 may have two or more branches 21d that branch from each of the plurality of leads 19 and reach the main part 23 (FIG. 13).

[0149] In this case, for example, the connection path of the extending portion 11c (the portion of the lead 19 and the specific wiring 21 that is not covered by the main part 23) to the main part 23 increases. As a result, for example, the wiring resistance of the extending portion 11c decreases, and the power consumption of the head 1 decreases. Also, for example, in a situation where the head 1 is being used, 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, the continuity of the extending portion 11c is maintained by the remaining branches 21d. Therefore, the corresponding heat generating portion 5 does not completely become unable to be printed, but for example, only the printing density decreases. 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 be bridged between adjacent ones of the plurality of leads 19. Each bridge 21a may be inclined with respect to the first direction (D1 direction) (the upper and middle portions of FIGS. 4 and 6, and the upper to lower portions of FIG. 7, etc.).

[0151] In this case, for example, by a simple configuration that tilts the bridge 21a, a change in the position of the lateral edge 21b in the D2 direction can be realized. Also, for example, as in the upper example of FIG. 6, while realizing a change in the position of the lateral edge 21b in the D2 direction, the shape of the bridge 21a can be made linear and extending with a constant width. In this case, for example, compared to a mode in which the bridge 21a bends (e.g., the middle example of FIG. 6), even when the gap between the leads 19 is small, it is easy to change the position of the lateral edge 21b in the D2 direction. Also, for example, when a virtual straight line parallel to the D1 direction (not shown) is assumed, the virtual straight line crosses the lateral edge 21b of the bridge 21a (e.g., in the lower example of FIG. 6, the virtual straight line does not cross the lateral edge 21b). Therefore, for example, when a gravure is used, it is difficult for a doctor blade parallel to the D1 direction to enter the recess corresponding to the bridge 21a.

[0152] Each of the plurality of bridges 21a may be bent (e.g., the middle of FIGS. 5 and 6 and the lower part of FIG. 7, etc.).

[0153] In this case, for example, by a simple configuration in which the bridge 21a bends, a change in the position of the lateral edge 21b in the D2 direction can be realized. Also, for example, as in the middle example of FIG. 6, while realizing a change in the position of the lateral edge 21b in the D2 direction, the shape of the bridge 21a can be made symmetric (e.g., in the upper example of FIG. 6, the bridge 21a is not symmetric). Thereby, for example, the mechanical or electrical influence exerted by each bridge 21a on the leads 19 on both sides can be made equal. As a result, the probability of occurrence of an unintended shape error or electrical error is reduced. Also, similar to the case where the bridge 21a is tilted, since a virtual straight line parallel to the D1 direction (not shown) crosses the lateral edge 21b, it is difficult for a doctor blade parallel to the D1 direction to enter the recess corresponding to the bridge 21a.

[0154] Among the plurality of bridges 21a, the adjacent bridges 21a may have different positions in the second direction (D2 direction) (e.g., the lower part of FIG. 6, the upper and middle parts of FIG. 7, etc.).

[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 to minimize the area of the bridge 21a while changing the position of the specific wiring 21 in the D2 direction. Also, for example, as in the examples in the upper and middle parts of FIG. 7, while inclining (or bending) the bridge 21a and varying the positions of adjacent bridges 21a, the arrangement range of the specific wiring 21 in the D2 direction can be widened to improve the reliability of the junction between the first conductor layer 15 and the main part 23. In any case, it is possible to improve the reliability of the junction while reducing the junction area.

[0156] In the case of a plurality of bridges 21a, the innermost part (corner 21f or 21m) of the recess formed by the lateral edge part 21b on the first side (+D2 side) in the second direction (D2 direction) may be located on the -D2 side with respect to the innermost part (corner 21f or 21n) of the recess formed by the lateral edge part 21b on the second side (-D2 side) in the D2 direction (upper and lower parts of FIG. 12).

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

[0158] The specific wiring 21 may be in a net shape (upper and lower parts of FIG. 10, etc.).

[0159] In this case, for example, when assuming a virtual straight line (not shown) parallel to the D1 direction passing through the most -D2 side position of the specific wiring 21 and a virtual straight line (not shown) parallel to the D1 direction passing through the most +D2 side position of the specific wiring 21, compared with the basic pattern (FIG. 6, etc.), the distribution of the first conductor layer 15 in the region sandwiched between the two virtual straight lines becomes uniform. Consequently, the reliability of the connection between the first conductor layer 15 and the main part 23 is uniformly improved 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 mutual diffusion between the first conductor layer 15 and the main portion 23 is reduced to a certain extent. As a result, the above-described effects are likely to be achieved.

[0162] In the above embodiments, the printer 101 is an example of a recording device. The transport device 103 is an example of a moving part.

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

[0164] The recording device may be a plotter. The recording device may be a handy printer that is entirely held and moved by a user's hand and relatively moves with respect to a recording medium. The recording device may be one that relatively moves a recording medium and a head by moving the head by 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 having a heat-sensitive layer formed on the surface. Also, in a mode where transfer is performed as in a mode using an ink ribbon, it is obvious that various media (for example, cloth, wood, or tile) can be used instead of paper.

[0166] From the present disclosure, inventions that do not require requirements such as the side edge of a specific wiring changing its position in the second direction may be extracted. For example, an invention in which the first conductor layer has a protruding portion protruding to the side opposite to the heat generating portion from the specific wiring may be extracted. Also, for example, an invention in which part or all of the specific wiring is in a net shape may be extracted.

[0167] From the present disclosure, the following concepts can be extracted. (Concept 1) A plurality of heat generating portions arranged in the first direction, The first conductor layer, A second conductor layer having a lower electrical resistivity than the first conductor layer, and having, The first conductor layer includes, a plurality of leads extending in a second direction intersecting the first direction from the plurality of heat generating portions, and a 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 part of the length of the main portion in the second direction, At least one of the lateral edge portions on both sides of the specific wiring in the second direction changes its position in the second direction according to the position in the first direction in the region overlapping the main portion. A thermal head. (Concept 2) The first conductor layer has a plurality of protruding portions that protrude to the side opposite to the plurality of heat generating portions from the specific wiring and are covered by the main portion. The thermal head according to Concept 1. (Concept 3) The corners of the outer edge of the first conductor layer are curved in the region overlapping the main portion. The thermal head according to Concept 1 or 2. (Concept 4) Due to the corners being curved in a concave shape, the specific wiring becomes thinner at the corners. The thermal head according to Concept 3. (Concept 5) The specific wiring is located on the side of the plurality of heat generating portions rather than the center of the main portion in the second direction. The thermal head according to any one of Concepts 1 to 4. (Concept 6) The specific wiring has two or more branches that branch from each of the plurality of leads and reach the main portion. The thermal head according to any one of Concepts 1 to 5. (Concept 7) The specific wiring has a plurality of bridges respectively bridging between 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 any one of Concepts 1 to 6. (Concept 8) The specific wiring has a plurality of bridges respectively bridging between adjacent ones of the plurality of leads. Each of the plurality of bridges is bent. The thermal head according to any one of Concepts 1 to 7. (Concept 9) The specific wiring has a plurality of bridges respectively bridging between adjacent ones of the plurality of leads. In the plurality of bridges, adjacent bridges have different positions in the second direction. The thermal head according to any one of Concepts 1 to 8. (Concept 10) The specific wiring has a plurality of bridges respectively bridging between adjacent ones of the plurality of leads. In the plurality of bridges, the innermost part of the recess formed by the lateral edge portion on the first side in the second direction is located closer to the second side than the innermost part of the recess formed by the lateral edge portion on the second side in the second direction. The thermal head according to any one of Concepts 1 to 9. (Concept 11) The specific wiring is reticular. The thermal head according to any one of Concepts 1 to 10. (Concept 12) The area where the first conductor layer overlaps the main part is 80% or less of the area of the main part. The thermal head according to any one of Concepts 1 to 11. (Concept 13) The thermal head according to any one of Concepts 1 to 12, a moving unit that relatively moves the thermal head and a recording medium, and a recording apparatus having the same.

Description of Symbols

[0168] 101…Printer (recording device), 1…Head (thermal head), 3…Head body (thermal head), 5…Heat generating part, 15…First conductor layer, 17…Second conductor layer, 19…Lead, 21…Specific wiring, 23…Main part.

Claims

1. A glaze extending in a first direction, a plurality of heating elements overlapping the glaze and arranged in the first direction, a first conductor layer, a second conductor layer, and having, wherein the first conductor layer extends from the plurality of heating elements to a first side in a second direction intersecting the first direction, and a plurality of leads in which a portion on a second side opposite to the first side overlaps the glaze, is located on the first side of the glaze and has a specific wiring connecting the plurality of leads to each other, the second conductor layer has a main portion overlapping at least a part of the specific wiring, the specific wiring overlaps a part of the length of the main portion in the second direction, at least one of the lateral edge portions on both sides of the specific wiring in the second direction changes its position in the second direction according to the position in the first direction in the region overlapping the main portion thermal head.

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

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

4. The specific wiring is thinned at the corner portion because the corner portion is curved in a concave shape The thermal head according to claim 3.

5. The specific wiring is located on the second side of 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 that branch from each of the plurality of leads and reach the main portion The thermal head according to claim 1.

7. The specific wiring has a plurality of bridges bridging between 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 bridging between adjacent ones of the plurality of leads, each of the plurality of bridges is bent The thermal head according to claim 1.

9. The specific wiring has a plurality of bridges bridging between adjacent ones of the plurality of leads, In the plurality of bridges, adjacent bridges have different positions in the second direction. The thermal head according to claim 1.

10. The specific wiring has a plurality of bridges respectively bridging adjacent ones of the plurality of leads. In the plurality of bridges, the innermost part of the recess formed by the side edge portion on the first side is located on the second side with respect to the innermost part of the recess formed by the side edge portion on the second side. The thermal head according to claim 1.

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

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

13. A thermal head according to any one of claims 1 to 12, a moving unit that relatively moves the thermal head and a recording medium, and a recording apparatus having the same.

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