Thermal print head and thermal printer

Abstract

A thermal print head (A1) comprises a substrate body (1) having a main surface (1a) that faces a first side (z1) in the thickness direction (z) and a rear surface (1b) that faces a second side (z2) on the opposite side from the first side (z1). The thermal print head (1A) also comprises an electrode layer, a resistor layer (4), and a drive IC (7) that are supported on the main surface (1a), a heat dissipation member (8) that has a support surface (81) which supports the substrate body (1) and faces the first side (z1) in the thickness direction (z), and an IC chip (6) that is mounted on the rear surface (1b) of the substrate body (1) and that has a memory function. The heat dissipation member (8) has a recess (82) that is recessed toward the second side (22) in the thickness direction (z) from the support surface (81), and that accommodates at least part of the IC chip (6).

Description

Thermal printheads and thermal printers

[0001] The present disclosure relates to a thermal printhead and a thermal printer.

[0002] Thermal printheads have been used as devices that print by applying heat to thermal paper or thermal ink ribbons. For example, Japanese Patent Application Laid-Open No. 2003-125998 discloses a conventional thermal printhead. The thermal printhead described in Japanese Patent Application Laid-Open No. 2003-125998 includes a substrate, a glaze layer, an electrode layer, a resistor layer, a protective layer, a drive IC, and a sealing resin.

[0003] Japanese Patent Application Laid-Open No. 2018-103608

[0004] The usage history information and detailed resistance value information of each thermal printhead are unique to each thermal printhead, and storing such unique information in the thermal printhead is preferable for more appropriate use of the thermal printhead.

[0005] An object of the present disclosure is to provide a thermal printhead that is improved over conventional ones. In particular, in view of the above-mentioned circumstances, an object of the present disclosure is to provide a thermal printhead that can more appropriately store unique information, and to provide a thermal printer equipped with such a thermal printhead.

[0006] A thermal printhead according to a first aspect of the present disclosure includes a substrate having a main surface facing a first side in a thickness direction and a back surface facing a second side opposite the first side, an electrode layer, a resistor layer, and a driving IC supported on the main surface, and a heat dissipation member having a support surface facing the first side in the thickness direction and supporting the substrate. The thermal printhead also includes an IC chip having a memory function mounted on the back surface of the substrate. The heat dissipation member has a recess recessed from the support surface toward the second side in the thickness direction and accommodating at least a portion of the IC chip.

[0007] According to the above configuration, it is possible to provide a thermal printhead that can store unique information more appropriately, and further, a thermal printer equipped with such a thermal printhead.

[0008] Other features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0009] FIG. 1 is a plan view showing a thermal printhead according to a first embodiment of the present disclosure. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1 , showing a printer according to the first embodiment of the present disclosure. FIG. 3 is a plan view showing a main portion of a thermal printhead according to the first embodiment of the present disclosure. FIG. 4 is an enlarged plan view showing a main portion of a thermal printhead according to the first embodiment of the present disclosure. FIG. 5 is an enlarged cross-sectional view showing a main portion of a thermal printhead according to the first embodiment of the present disclosure, taken along line V-V in FIG. 4. FIG. 6 is an enlarged cross-sectional view showing a main portion of a thermal printhead according to the first embodiment of the present disclosure. FIG. 7 is an enlarged cross-sectional view showing a main portion of a thermal printhead according to the first embodiment of the present disclosure. FIG. 8 is an enlarged cross-sectional view showing a first modified example of a thermal printhead according to the first embodiment of the present disclosure. FIG. 9 is an enlarged cross-sectional view showing a second modified example of a thermal printhead according to the first embodiment of the present disclosure. FIG. 10 is an enlarged cross-sectional view showing a third modified example of a thermal printhead according to the first embodiment of the present disclosure. FIG. 11 is an enlarged cross-sectional view showing a fourth modified example of a thermal printhead according to the first embodiment of the present disclosure. Fig. 12 is an enlarged cross-sectional view of a main portion showing a fifth modified example of the thermal printhead according to the first embodiment of the present disclosure. Fig. 13 is an enlarged cross-sectional view of a main portion showing a sixth modified example of the thermal printhead according to the first embodiment of the present disclosure. Fig. 14 is an enlarged cross-sectional view of a main portion showing a seventh modified example of the thermal printhead according to the first embodiment of the present disclosure. Fig. 15 is a plan view showing a thermal printhead according to a second embodiment of the present disclosure.

[0010] Preferred embodiments of the present disclosure will now be described in detail with reference to the drawings.

[0011] The terms "first," "second," "third," etc. in this disclosure are used for identification purposes only and are not intended to impose any ranking on their objects.

[0012] In this disclosure, unless otherwise specified, "a certain object A is formed on a certain object B" and "a certain object A is formed on a certain object B" include "a certain object A is formed directly on a certain object B" and "a certain object A is formed on a certain object B with another object interposed between the certain object A and the certain object B." Similarly, "a certain object A is disposed on a certain object B" and "a certain object A is disposed on a certain object B" include "a certain object A is disposed directly on a certain object B" and "a certain object A is disposed on a certain object B with another object interposed between the certain object A and the certain object B" unless otherwise specified. Similarly, "a certain object A is located on a certain object B" includes "a certain object A is located on a certain object B with a certain object A in contact with the certain object B" and "a certain object A is located on a certain object B with another object interposed between the certain object A and the certain object B." Furthermore, unless otherwise specified, the phrase "an object A overlaps an object B when viewed in a certain direction" includes "an object A overlaps the entire object B" and "an object A overlaps a part of an object B." Furthermore, in the present disclosure, "a surface A faces in (one side or the other side of) direction B" is not limited to the case where the angle of surface A with respect to direction B is 90°, but also includes the case where surface A is tilted with respect to direction B.

[0013] 1 to 5 show a thermal printhead A1 and a thermal printer P1 according to a first embodiment of the present disclosure. The thermal printhead A1 includes a substrate 1, a protective layer 2, an electrode layer 3, a resistor layer 4, a second substrate 1B, multiple wires 91 and 92, multiple driver ICs 7, a protective resin 78, and a heat dissipation member 8. The thermal printhead A1 is incorporated into a thermal printer P1 that prints on a print medium C (see FIG. 2).

[0014] The thermal printer P1 includes a thermal printhead A1 and a platen roller B. The platen roller B faces the thermal printhead A1. A print medium C is sandwiched between the thermal printhead A1 and the platen roller B and is transported by the platen roller B in the sub-scanning direction y. Examples of such print media C include thermal paper for creating barcode sheets and receipts. A flat rubber platen may be used instead of the platen roller B. This platen includes a cylindrical rubber piece with a large radius of curvature and a portion that is arch-shaped in cross section.

[0015] FIG. 1 is a plan view showing a thermal printhead A1. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1, showing a thermal printer P1. FIG. 3 is a plan view selectively showing the first substrate 1A, electrode layer 3, resistor layer 4, and multiple driver ICs 7 of the thermal printhead A1. FIG. 4 is an enlarged plan view showing the thermal printhead A1. FIG. 5 is an enlarged cross-sectional view taken along line V-V in FIG. 4. FIGS. 6 and 7 are enlarged cross-sectional views showing the thermal printhead A1.

[0016] In these figures, the thickness direction of the present disclosure is defined as the thickness direction z. The first side of the thickness direction z is referred to as the z1 side, and the second side opposite the first side of the thickness direction z is referred to as the z2 side. Furthermore, a direction perpendicular to the thickness direction z is defined as the main scanning direction x. The first side of the main scanning direction x may be referred to as the x1 side, and the second side opposite the x1 side may be referred to as the x2 side. Furthermore, the direction perpendicular to the thickness direction z and the main scanning direction x is defined as the sub-scanning direction y. The first side of the sub-scanning direction y may be referred to as the y1 side, and the second side opposite the y1 side may be referred to as the y2 side.

[0017] The substrate body 1 is a support member that supports the protective layer 2, electrode layer 3, resistor layer 4, IC chip 6, and multiple driver ICs 7. The substrate body 1 has a main surface 1a and a back surface 1b. The main surface 1a faces the z1 side in the thickness direction z. The back surface 1b faces the z2 side in the thickness direction z. The substrate body 1 may be composed of a single plate-like member, or may be composed of multiple plate-like members. Examples of materials for the substrate body 1 include insulating materials such as ceramics and glass epoxy resin, and semiconductors such as Si (silicon).

[0018] The substrate body 1 of this embodiment includes a first substrate 1A and a second substrate 1B. As shown in FIG. 1 , the first substrate 1A is a plate-like substrate extending elongatedly in the primary scanning direction x. The first substrate 1A has a base material 11 and a glaze layer 12. The first substrate 1A also has a first region 1Aa and a second region 1Ab. The first region 1Aa is a part of the main surface 1a and is the surface of the first substrate 1A facing the z1 side in the thickness direction z. The second region 1Ab is a part of the back surface 1b and is the surface of the first substrate 1A facing the z2 side in the thickness direction z.

[0019] The substrate 11 includes a ceramic such as AlN (aluminum nitride), Al2O3 (alumina), or zirconia, and has these ceramics as its main component. The substrate 11 has a thickness of 0.6 mm or more and 1.0 mm or less. As shown in FIG. 1 , the substrate 11 has a rectangular shape extending in the main scanning direction x in a plan view (viewed in the z direction).

[0020] The glaze layer 12 is formed on the first main surface 11a of the substrate 11. The glaze layer 12 covers the first main surface 11a. The glaze layer 12 is made of a glass material such as amorphous glass. The glaze layer 12 in this example includes a bulging portion 122 and a flat portion 121. Note that the glaze layer 12 may also include the flat portion 121 but not the bulging portion 122.

[0021] The bulging portion 122 extends elongatedly in the main scanning direction x. When viewed in the main scanning direction x, the bulging portion 122 bulges in the thickness direction z. As shown in FIG. 4 , the bulging portion 122 has an arc-shaped cross section (y-z cross section) taken along a plane perpendicular to the main scanning direction x. The bulging portion 122 is provided to facilitate pressing the heat-generating portion of the resistor layer 4 (the heat-generating portion 41 described below) against the print medium C. The bulging portion 122 also serves as a heat storage layer that accumulates heat from the heat-generating portion 41. The dimension (maximum dimension) of the bulging portion 122 in the thickness direction z is larger than that of the flat portion 121. The maximum thickness of the bulging portion 122 is, for example, 5 μm or more and 10 μm or less.

[0022] The flat portion 121 is formed adjacent to the bulging portion 122, and has a flat surface on the z1 side in the thickness direction z. The thickness of the flat portion 121 is, for example, about 2.0 μm. The flat portion 121 covers the first main surface 11 a of the base material 11, which is a relatively rough surface, to provide a smooth surface suitable for forming the electrode layer 3.

[0023] There are no limitations on the softening point of the glaze layer 12. The softening point of the flat portion 121 and the softening point of the bulging portion 122 may be the same or different from each other. The softening points of the flat portion 121 and the bulging portion 122 are, for example, 800°C or higher and 850°C or lower, or, for example, approximately 680°C.

[0024] As shown in FIGS. 1 and 2 , the second substrate 1B is disposed on the y2 side of the first substrate 1A in the sub-scanning direction y. While the shape of the second substrate 1B is not particularly limited, in this embodiment, it is rectangular with its longitudinal direction aligned with the main scanning direction x. The second substrate 1B is, for example, a printed wiring board, with a wiring pattern (not shown) formed on a base material made of, for example, glass epoxy resin. The second substrate 1B has a third region 1Ba and a fourth region 1Bb. The third region 1Ba is a part of the main surface 1a and is the surface of the second substrate 1B facing the z1 side in the thickness direction z. The fourth region 1Bb is a part of the back surface 1b and is the surface of the second substrate 1B facing the z2 side in the thickness direction z. In the illustrated example, the positions of the first region 1Aa and the third region 1Ba in the thickness direction z are slightly different, but may be the same. Furthermore, in the illustrated example, the second region 1Ab and the fourth region 1Bb are the same in the thickness direction z, but may be different from each other. In this embodiment, the above-mentioned wiring patterns are formed in appropriate positions in both the third region 1Ba and the fourth region 1Bb.

[0025] 1 and 2, the first substrate 1A and the second substrate 1B are electrically connected by a connection member 18. The connection member 18 electrically connects appropriate locations of the electrode layer 3 formed on the first substrate 1A with appropriate locations of the wiring pattern on the second substrate 1B. The specific configuration of the connection member 18 is not limited in any way, and a member similar to a lead made of a metal plate material or the like, a metal wire, a conductive bonding material, or the like can be used as appropriate.

[0026] In this embodiment, a plurality of connection members 18, each made of a material similar to a lead, are used. The plurality of connection members 18 are arranged in the main scanning direction x. The specific structure of the connection members 18 is not limited in any way, and in the illustrated example, the connection members 18 have a first connection portion 181 and a second connection portion 182. The first connection portion 181 has a shape that sandwiches the first substrate 1A in the thickness direction z and contacts the first region 1Aa and the second region 1Ab. The second connection portion 182 is, for example, pin-shaped and is conductively joined to the wiring pattern of the second substrate 1B by, for example, solder (not shown).

[0027] The electrode layer 3 is supported on the main surface 1a of the substrate body 1. In this embodiment, the electrode layer 3 is supported on the first region 1Aa of the first substrate 1A. The electrode layer 3 forms a conductive path for passing electricity to the resistor layer 4. The electrode layer 3 is formed of a conductive material. The electrode layer 3 is a metal containing, for example, Au (gold). The electrode layer 3 is formed on the glaze layer 12 of the first substrate 1A. The thickness of the electrode layer 3 is, for example, 1 μm or more and 7.5 μm or less (preferably approximately 5.0 μm). As shown in FIGS. 4 and 5 , the electrode layer 3 has a common electrode 31 and multiple individual electrodes 34. Note that the shape and arrangement of each component of the electrode layer 3 are not limited to the examples shown in FIGS. 4 and 5 and can have various configurations. Furthermore, the material of each component of the electrode layer 3 is not limited in any way.

[0028] As shown in FIG. 4 , the common electrode 31 has a plurality of strip-shaped portions 32 and connecting portions 33. The connecting portions 33 are arranged near the edge of the first substrate 1A on the y1 side in the sub-scanning direction y and are strip-shaped extending in the main scanning direction x. The plurality of strip-shaped portions 32 each extend from the connecting portion 33 in the sub-scanning direction y and are arranged at equal intervals in the main scanning direction x. In the example shown in FIG. 4 , an auxiliary layer 331 is laminated on the connecting portion 33 to reduce the resistance value of the connecting portion 33, but the auxiliary layer 331 does not have to be laminated. The auxiliary layer 331 is formed, for example, by printing and firing a paste containing an organic Ag (silver) compound or a paste containing Ag (silver) particles, glass frit, Pd (palladium), and a resin.

[0029] The plurality of individual electrodes 34 are used to partially apply electricity to the resistor layer 4. Each individual electrode 34 has an opposite polarity to the common electrode 31. Each individual electrode 34 extends from the resistor layer 4 toward the driving IC 7. The plurality of individual electrodes 34 are arranged in the main scanning direction x. Each of the plurality of individual electrodes 34 has a strip portion 35, a connecting portion 36, and a bonding portion 37.

[0030] 4, the strip portions 35 extend in the sub-scanning direction y and are strip-shaped when viewed in the thickness direction z. Each strip portion 35 is located between two adjacent strip portions 32 of the common electrode 31. The distance between the strip portions 35 of adjacent individual electrodes 34 and the strip portions 32 of the common electrode 31 is, for example, 50 μm or less.

[0031] The connecting portion 36 is a portion that extends from the strip portion 35 toward the driving IC 7. The connecting portion 36 includes a parallel portion 361 and an inclined portion 362. One end of the parallel portion 361 is connected to the bonding portion 37 and extends along the sub-scanning direction y. The inclined portion 362 is inclined with respect to the sub-scanning direction y. The inclined portion 362 is sandwiched between the parallel portion 361 and the strip portion 35 in the sub-scanning direction y. Furthermore, the multiple individual electrodes 34 are concentrated on the driving IC 7.

[0032] As shown in FIG. 4 , the bonding portions 37 are formed on the end of the individual electrodes 34 on the y2 side in the sub-scanning direction y, and each is connected to a corresponding parallel portion 361. A wire 91 is bonded to each bonding portion 37. This establishes electrical continuity between each individual electrode 34 and the driving IC 7 via the wire 91. The bonding portions 37 include a first bonding portion 37A and a second bonding portion 37B. The width (length in the main scanning direction x) of the parallel portion 361 sandwiched between two adjacent first bonding portions 37A is, for example, 10 μm or less. The second bonding portion 37B is located farther from the resistor layer 4 than the first bonding portion 37A in the sub-scanning direction y. The second bonding portion 37B is connected to the parallel portion 361 sandwiched between two adjacent first bonding portions 37A. This configuration prevents the bonding portions 37 from interfering with each other, even though they are wider than most of the connecting portion 36. The portion of the connecting portion 36 that is sandwiched between adjacent first bonding portions 37A has the smallest width on the individual electrode 34.

[0033] The resistor layer 4 is supported on the main surface 1a of the substrate body 1. In this embodiment, the resistor layer 4 is supported on the first region 1Aa of the first substrate 1A. The resistor layer 4 is formed using a material with a higher resistivity than the material constituting the electrode layer 3. The resistor layer 4 includes, for example, ruthenium oxide. In this example, the resistor layer 4 is formed on the bulge portion 122, as shown in FIGS. 4 and 5 . The shape of the resistor layer 4 as viewed in the thickness direction z is not limited. In this embodiment, as shown in FIGS. 1 and 4 , the resistor layer 4 has a strip shape extending in the main scanning direction x. The resistor layer 4 straddles each strip portion 32 (common electrode 31) and each strip portion 35 (individual electrode 34). In the thickness direction z, the resistor layer 4 is stacked on the z1 side of the multiple strip portions 32 and the multiple strip portions 35.

[0034] The portions of the resistor layer 4 sandwiched between the strip portions 32 and 35 are defined as heat generating portions 41. The heat generating portions 41 generate heat when partially energized by the electrode layer 3. Print dots are formed by the heat generated by each heat generating portion 41. The heat generating portions 41 are arranged in the main scanning direction x. The greater the number of heat generating portions 41 arranged in the main scanning direction x per unit length (e.g., 1 mm) of the first substrate 1A in the main scanning direction x, the greater the dot density of the thermal printhead A1.

[0035] The thickness of the resistor layer 4 is, for example, 3 μm to 6 μm The material and thickness of the resistor layer 4 are not limited.

[0036] The protective layer 2 is intended to protect the electrode layer 3, the resistor layer 4, and the like. The protective layer 2 may be composed of a single layer or a laminate of multiple layers. The material of the protective layer 2 is not limited in any way. One example of the protective layer 2 is one that is primarily composed of amorphous glass. Another example of the protective layer 2 is one in which a first layer made of amorphous glass is laminated with a second layer made of SiAlON. SiAlON is a silicon nitride-based engineering ceramic obtained by combining SiN (silicon nitride) with AlO (alumina) and SiO (silica). The second layer is formed, for example, by sputtering. SiC (silicon carbide) may be used for the second layer instead of SiAlON.

[0037] A plurality of driving ICs 7 are mounted on the main surface 1a. In this embodiment, the plurality of driving ICs 7 are mounted in the first region 1Aa. The plurality of driving ICs 7 are used to individually energize the plurality of heat generating portions 41. Unlike this embodiment, the plurality of driving ICs 7 may be mounted across the first substrate 1A and the second substrate 1B, or may be mounted on the second substrate 1B. The plurality of driving ICs 7 are connected to the plurality of individual electrodes 34 (the plurality of bonding portions 37) by a plurality of wires 91. The control of energization of the plurality of heat generating portions 41 by the plurality of driving ICs 7 is based on a command signal input from outside the thermal printhead A1 via the second substrate 1B. The plurality of driving ICs 7 are connected to other portions (not shown) of the electrode layer 3 of the first substrate 1A by a plurality of wires 92. The plurality of driving ICs 7 are appropriately provided according to the number of heat generating portions 41.

[0038] The plurality of driver ICs 7, the plurality of wires 91 and the plurality of wires 92 are covered with a protective resin 78. The protective resin 78 is made of, for example, an insulating resin and is, for example, black.

[0039] Connectors 58 and 59 are attached to the second substrate 1B. The connectors 58 and 59 are used to connect the thermal printhead A1 to the thermal printer. The connectors 58 and 59 are connected to a wiring pattern (not shown) on the second substrate 1B. One of the connectors 58 and 59 is a connector for inputting, for example, power to drive the thermal printhead A1, and the other is a connector for inputting a control signal to drive the thermal printhead A1.

[0040] The IC chip 6 has a memory function for storing information specific to the thermal printhead A1 and incorporates an integrated circuit. Examples of the information specific to the thermal printhead A1 include, but are not limited to, usage history information and detailed resistance value information for the thermal printhead A1. Any information specific to each individual thermal printhead A1 may be stored. The IC chip 6 may have only a memory function, or may have an arithmetic and control function in addition to the memory function. As shown in FIGS. 1, 2, and 6, the IC chip 6 is mounted on the rear surface 1b. In this embodiment, the IC chip 6 is mounted in the fourth region 1Bb of the second substrate 1B and protrudes from the rear surface 1b toward the z2 side in the thickness direction z. In the illustrated example, the IC chip 6 is surface-mounted in the fourth region 1Bb.

[0041] There is no limitation on the specific configuration of the IC chip 6. In the illustrated example, the IC chip 6 has a semiconductor element 61, a plurality of leads 62, a plurality of wires 63, and a sealing resin 64.

[0042] The semiconductor element 61 is a semiconductor element or the like that performs the memory function of the IC chip 6. The plurality of leads 62 supports the semiconductor element 61 and also forms a conductive path to the semiconductor element 61. For example, the semiconductor element 61 is die-bonded to one of the plurality of leads 62.

[0043] The plurality of wires 63 are connected to the semiconductor element 61 and any of the plurality of leads 62. The wires 63 contain, for example, Au (gold). The sealing resin 64 covers the semiconductor element 61, the plurality of wires 63, and portions of each of the plurality of leads 62. The sealing resin 64 is, for example, a black epoxy resin.

[0044] In this embodiment, the IC chip 6 is surface-mounted with solder 68 at appropriate locations on the wiring pattern (not shown) of the second substrate 1B.

[0045] 1, 2, and 6, the heat dissipation member 8 supports the substrate body 1. The heat dissipation member 8 serves to dissipate a portion of the heat generated by the plurality of heat-generating portions 41 to the outside via the first substrate 1A. The heat dissipation member 8 includes a metal such as Al (aluminum). As shown in FIG. 2, the heat dissipation member 8 has a support surface 81, a recess 82, and a groove 83.

[0046] The support surface 81 faces the z1 side in the thickness direction z. The back surface 1b of the substrate body 1 faces the support surface 81, and the back surface 1b is fixed thereto, for example, with an adhesive or adhesive tape (not shown). In this embodiment, the support surface 81 includes a first support region 81A and a second support region 81B. The first support region 81A and the second support region 81B are spaced apart from each other in the sub-scanning direction y. The first support region 81A is located on the y1 side of the sub-scanning direction y, and the second support region 81B is located on the y2 side of the sub-scanning direction y. The first support region 81A supports the first substrate 1A, and the second region 1Ab is bonded thereto, for example. The second support region 81B supports the second substrate 1B, and the fourth region 1Bb is bonded thereto, for example.

[0047] The recess 82 is recessed from the support surface 81 toward the z2 side in the thickness direction z. In this embodiment, the recess 82 is recessed from the second support region 81B toward the z2 side in the thickness direction z. The recess 82 accommodates at least a portion of the IC chip 6. In this embodiment, the recess 82 accommodates the entire IC chip 6. As viewed in the thickness direction z, the recess 82 overlaps the entire IC chip 6. As viewed in the main scanning direction x and the sub-scanning direction y, the recess 82 overlaps at least a portion of the IC chip 6, and in this embodiment, the recess 82 overlaps the entire IC chip 6. The shape of the recess 82 is not limited in any way, and in the illustrated example, it is rectangular as viewed in the thickness direction z. The recess 82 also has a bottom surface 821 and a side surface 822. The bottom surface 821 is a surface located on the z2 side in the thickness direction z. The side surface 822 is a surface connecting the second support region 81B (support surface 81) and the bottom surface 821. In the illustrated example, for example, when the thickness of the IC chip 6 in the thickness direction z is about 0.6 mm, the depth of the groove portion 83 in the thickness direction z is greater than the thickness of the IC chip 6 in the thickness direction z, for example, about 1.0 mm.

[0048] In the illustrated example, the thermal printhead A1 includes a bonding material 69. The bonding material 69 bonds the IC chip 6 to the inner surface of the recess 82. The amount of the bonding material 69 and the area where the bonding material 69 is provided are not limited. In the illustrated example, the bonding material 69 fills the entire space between the IC chip 6 and the inner surface of the recess 82. The specific type of bonding material 69 is not limited, and various bonding materials can be used. Examples of the bonding material 69 include a room-temperature curing epoxy resin adhesive composed of one liquid or two liquids that are mixed together. Furthermore, a thermosetting adhesive, an ultraviolet-curing adhesive, or the like may also be used as the bonding material 69. In this embodiment, the bonding strength between the IC chip 6 and the inner surface of the recess 82 provided by the bonding material 69 is stronger than the mounting strength of the IC chip 6 to the back surface 1b of the substrate 1 (the fourth region 1Bb of the second substrate 1B).

[0049] The grooves 83 are recessed from the support surface 81 toward the z2 side in the thickness direction z and extend in the main scanning direction x. In this example, the grooves 83 reach both ends of the heat dissipation member 8 in the main scanning direction x. The grooves 83 separate the first support region 81A and the second support region 81B. The grooves 83 also accommodate portions of the first connection portions 181 of the plurality of grooves 83. In the illustrated example, the depth of the grooves 83 in the thickness direction z is deeper than the depth of the recesses 82 in the thickness direction z.

[0050] Next, the operation of the thermal printhead A1 and the thermal printer P1 will be described.

[0051] According to this embodiment, the thermal printhead A1 is equipped with an IC chip 6 that has a memory function for storing unique information. The IC chip 6 is mounted on the rear surface 1b and housed in a recess 82 in the heat dissipation member 8. This makes the IC chip 6 less susceptible to external shocks, erosion, and the like. This allows the unique information to be stored more appropriately.

[0052] The IC chip 6 is bonded to the inner surface of the recess 82 by a bonding material 69. The bonding strength between the IC chip 6 and the inner surface of the recess 82 by the bonding material 69 is stronger than the mounting strength of the IC chip 6 to the back surface 1b of the substrate body 1 (the fourth region 1Bb of the second substrate 1B). As a result, if, for example, a person unintended by the user or manufacturer of the thermal printhead A1 and the thermal printer P1 improperly disassembles the thermal printhead A1 and the thermal printer P1, an attempt may be made to analyze the IC chip 6. In this embodiment, as shown in FIG. 7 , when the substrate body 1 (second substrate 1B) is removed from the support surface 81, the bonding strength of the bonding material 69 is stronger than the mounting strength of the IC chip 6 to the back surface 1b (the fourth region 1Bb), so the IC chip 6 peels off from the substrate body 1 (second substrate 1B) and remains in the recess 82 together with the bonding material 69. This prevents improper analysis of the IC chip 6.

[0053] Since the substrate body 1 includes a first substrate 1A and a second substrate 1B, the first substrate 1A, which functions as a so-called heat-generating substrate, and the second substrate 1B, which functions as a wiring substrate or connection substrate, can be configured to suit the functions required of each.

[0054] By providing the grooves 83 in the heat dissipation member 8 , for example, it is possible to avoid interference between the first connection portions 181 of the multiple connection members 18 and the support surface 81 .

[0055] 8 to 15 show other embodiments of the present disclosure. In these figures, elements that are the same as or similar to those in the above embodiment are given the same reference numerals. Furthermore, the configurations of the various parts in each of the modified examples and embodiments can be combined with each other as appropriate within the scope of not causing technical contradictions.

[0056] 8 shows a first modified example of the thermal printhead A1. The thermal printhead A11 of this modified example differs from the above-described embodiment in the amount of bonding material 69 in the space between the IC chip 6 and the inner surface of the recess 82. In this modified example, the bonding material 69 fills only part of the space between the IC chip 6 and the inner surface of the recess 82, rather than filling the entire space. The bonding material 69 is spaced apart from the fourth region 1Bb (second substrate 1B).

[0057] This modification also allows the unique information to be stored more appropriately. Furthermore, as can be seen from this modification, there are no specific limitations on the amount of bonding material 69. This modification prevents the bonding material 69 from spilling into unintended areas during the manufacture of the thermal printhead A1.

[0058] 9 shows a second modified example of the thermal printhead A1. The thermal printhead A12 of this modified example differs from the above-described embodiment in the amount of bonding material 69 in the space between the IC chip 6 and the inner surface of the recess 82. In this modified example, the bonding material 69 fills the entire space between the IC chip 6 and the inner surface of the recess 82, and also fills a portion of the space between the second support region 81B (support surface 81) and the fourth region 1Bb (second substrate 1B).

[0059] This modification also allows the unique information to be stored more appropriately. Furthermore, as can be seen from this modification, there is no limitation on the specific amount of bonding material 69. According to this modification, the bonding strength between second substrate 1B and support surface 81 can be further increased by bonding material 69.

[0060] 10 shows a third modified example of the thermal printhead A1. The thermal printhead A13 of this modified example differs from the above-described example in the specific configuration of the recess 82. In this example, the surface roughness of the inner surface of the recess 82 is greater than the surface roughness of the support surface 81 (second support region 81B). In the illustrated example, both the bottom surface 821 and the side surface 822 of the recess 82 have a surface roughness greater than that of the support surface 81 (second support region 81B). The specific index of surface roughness referred to here is not particularly limited, and any index that can be relatively compared using indices such as Ra (arithmetic mean roughness) and Rz (maximum height roughness) may be used.

[0061] The heat dissipation member 8 having such a configuration can be formed by forming the recess 82 by machining such as cutting in a member formed by extrusion molding of Al (aluminum), without performing any process such as smoothing on the inner surface of the recess 82. The amount of the bonding material 69 is not particularly limited, and in the example shown, the bonding material 69 fills the entire space between the IC chip 6 and the inner surface of the recess 82.

[0062] This modification also allows the unique information to be stored more appropriately. Furthermore, according to this modification, the surface roughness of the inner surface of the recess 82 is greater than the surface roughness of the support surface 81 (second support region 81B), thereby increasing the bonding strength between the recess 82 and the bonding material 69. This more reliably realizes a configuration in which the bonding strength between the IC chip 6 and the inner surface of the recess 82 by the bonding material 69 is greater than the mounting strength of the IC chip 6 to the back surface 1b of the substrate body 1 (fourth region 1Bb of the second substrate 1B).

[0063] 11 shows a fourth modified example of the thermal printhead A1. The thermal printhead A14 of this modified example differs from the above-described example in the configuration of the recess 82. In this modified example, the surface roughness of the bottom surface 821 is greater than the surface roughness of the second support region 81B (support surface 81), and the surface roughness of the side surface 822 is approximately the same as the surface roughness of the second support region 81B (support surface 81). This configuration can be achieved, for example, by changing the machining method and processing conditions used to form the recess 82.

[0064] This modification also allows the unique information to be stored more appropriately. As can be understood from this modification, only a portion of the recess 82 may have a surface roughness greater than that of the second support region 81B (support surface 81).

[0065] 12 shows a fifth modified example of the thermal printhead A1. The thermal printhead A15 of this modified example differs from the above-described embodiment in the configuration of the heat dissipation member 8. The heat dissipation member 8 of this modified example has a surface treatment layer 89. The surface treatment layer 89 constitutes the second support region 81B. The surface treatment layer 89 is a layer intended to protect and smooth the surface of the heat dissipation member 8. An example of the surface treatment layer 89 is an alumite treatment layer.

[0066] The surface treatment layer 89 is provided on the entire outer edge of the cross-sectional shape of the heat dissipation member 8 shown in Fig. 2, excluding the portion that forms the recess 82. In other words, the surface treatment layer 89 is not provided on the recess 82. Such a configuration can be achieved by performing an anodizing treatment after extrusion molding of Al (aluminum) to form the heat dissipation member 8, and then forming the recess 82 by machining or the like.

[0067] This modification also allows the unique information to be stored more appropriately. Furthermore, this modification can increase the bonding strength between the recess 82 and the bonding material 69 while preventing the entire heat dissipation member 8 from being altered or otherwise damaged.

[0068] 13 shows a sixth modified example of the thermal printhead A1. The thermal printhead A16 of this modified example differs from the above-described example in the configuration of the IC chip 6. The IC chip 6 of this modified example has an uneven surface of the sealing resin 64. There are no specific limitations on the specific method for making the sealing resin 64 uneven, and examples include a method of making the inner surface of a mold used to form the sealing resin 64 uneven, or a method of machining or chemically processing the molded sealing resin 64 to make it uneven.

[0069] This modification also allows the unique information to be stored more appropriately. Furthermore, this modification makes it possible to increase the bonding strength between the sealing resin 64 of the IC chip 6 and the bonding material 69. This more reliably realizes a configuration in which the bonding strength between the IC chip 6 and the inner surface of the recess 82 by the bonding material 69 is stronger than the mounting strength of the IC chip 6 to the back surface 1b of the substrate body 1 (the fourth region 1Bb of the second substrate 1B).

[0070] 14 shows a seventh modified example of the thermal printhead A1. The thermal printhead A17 of this modified example does not include the bonding material 69 of the above example. A gas such as air is present in the space between the IC chip 6 and the recess 82.

[0071] This modification also allows the unique information to be stored more appropriately. As can be seen from this modification, the present invention is not limited to the configuration in which the bonding material 69 is provided.

[0072] 15 shows a thermal printhead and a thermal printer according to a second embodiment of the present disclosure. A thermal printer P2 of this embodiment includes a thermal printhead A2. The thermal printhead A2 has a substrate 1 with a different configuration from the substrate 1 described above.

[0073] The substrate body 1 of this embodiment is composed of a single plate-like member. The main surface 1a and the back surface 1b each comprise a single region. The support surface 81 of the heat dissipation member 8 also comprises a single region. The heat dissipation member 8 does not necessarily have to have the groove 83 described above.

[0074] This embodiment also allows the unique information to be stored more appropriately. As can be understood from this embodiment, the substrate body 1 may be made up of a single plate-like member, or may be made up of a plurality of plate-like members.

[0075] The thermal printhead and thermal printer according to the present disclosure are not limited to the above-described embodiments. The specific configurations of the components of the thermal printhead and thermal printer according to the present disclosure can be freely modified in various ways. The present disclosure includes the embodiments described in the following appendices.

[0076] Supplementary Note 1. A thermal printhead comprising: a substrate body having a main surface facing a first side in a thickness direction and a back surface facing a second side opposite the first side; an electrode layer, a resistor layer, and a driver IC supported on the main surface; a heat dissipation member having a support surface facing the first side in the thickness direction and supporting the substrate body; and an IC chip mounted on the back surface of the substrate body and having a memory function, the heat dissipation member having a recess recessed from the support surface toward the second side in the thickness direction and accommodating at least a portion of the IC chip. Supplementary Note 2. The thermal printhead according to Supplementary Note 1, further comprising a bonding material that bonds the IC chip to the recess. Supplementary Note 3. The thermal printhead according to Supplementary Note 2, wherein the bonding strength between the IC chip and the recess provided by the bonding material is stronger than the mounting strength of the IC chip to the substrate body. Supplementary Note 4. The thermal printhead according to Supplementary Note 3, wherein the bonding material fills all of the space between the IC chip and the recess. Supplementary Note 5. The thermal printhead according to Appendix 3 or 4, wherein the IC chip is surface-mounted on the back surface. Appendix 6. The thermal printhead according to any one of Appendixes 2 to 5, wherein at least a portion of the inner surface of the recess has a surface roughness greater than that of the support surface. Appendix 7. The thermal printhead according to Appendix 6, wherein the entire inner surface of the recess has a surface roughness greater than that of the support surface. Appendix 8. The thermal printhead according to Appendix 6 or 7, wherein the heat dissipation member contains Al. Appendix 9. The thermal printhead according to Appendix 8, wherein the heat dissipation member has a surface treatment layer that constitutes the support surface. Appendix 10. The thermal printhead according to Appendix 9, wherein the surface treatment layer is an alumite treatment layer. Appendix 11. The thermal printhead according to any one of claims 1 to 10, wherein the substrate body includes: a first substrate having a first region that is a part of the main surface and a second region that is a part of the back surface and supporting the electrode layer and the resistor layer, and a second substrate having a third region that is a part of the main surface and a fourth region that is a part of the back surface and on which the IC chip is mounted.Appendix 13. The thermal printhead according to Appendix 11 or 12, further comprising a connector attached to the second substrate. Appendix 14. The thermal printhead according to any of Appendixes 11 to 13, further comprising a connection member that electrically connects the first substrate and the second substrate. Appendix 15. The thermal printhead according to Appendix 14, wherein the heat dissipation member has a groove that houses a portion of the connection member and extends in a main scanning direction perpendicular to the thickness direction. Appendix 16. The thermal printhead according to any of Appendixes 11 to 15, wherein the drive IC is mounted in the first region of the first substrate. Appendix 17. A thermal printer comprising the thermal printhead according to any of Appendixes 1 to 16.

[0077] A1, A11, A12, A13, A14: thermal print heads A15, A16, A17, A2: thermal print heads P1, P2: thermal printer 1: substrate body 1A: first substrate 1Aa: first region 1Ab: second region 1B: second substrate 1Ba: third region 1Bb: fourth region 1a: main surface 1b: back surface 2: protective layer 3: electrode layer 4: resistor layer 6: IC chip 7: driving IC 8: heat dissipation member 11: base material 11a: first main surface 12: glaze layer 18: connecting member 31: common electrode 32: strip-shaped portion 33: connecting portion 34: individual electrode 35: strip-shaped portion 36: connecting portion 37: bonding portion 37A: first bonding portion 37B: second bonding portion 41: heat-generating portion 58, 59: Connector 61: Semiconductor element 62: Lead 63: Wire 64: Sealing resin 68: Solder 69: Bonding material 78: Protective resin 81: Support surface 81A: First support region 81B: Second support region 82: Recess 83: Groove 89: Surface treatment layer 91, 92: Wire 121: Flat portion 122: Bulging portion 181: First connection portion 182: Second connection portion 331: Auxiliary layer 361: Parallel portion 362: Oblique portion 821: Bottom surface 822: Side surface B: Platen roller C: Printing medium x: Main scanning direction y: Sub-scanning direction z: Thickness direction

Claims

1. a substrate body having a main surface facing a first side in a thickness direction and a back surface facing a second side opposite to the first side; an electrode layer, a resistor layer, and a driving IC supported on the main surface; a heat dissipation member having a support surface facing the first side in the thickness direction and supporting the substrate body; an IC chip mounted on the back surface of the substrate and having a memory function; the heat dissipation member has a recess that is recessed from the support surface toward the second side in the thickness direction and that accommodates at least a portion of the IC chip.

2. The thermal printhead according to claim 1 , further comprising a bonding material that bonds the IC chip and the recess.

3. 3. The thermal printhead according to claim 2, wherein a bonding strength between said IC chip and said recess by said bonding material is stronger than a mounting strength of said IC chip to said substrate.

4. 4. The thermal printhead according to claim 3, wherein the bonding material fills the entire space between the IC chip and the recess.

5. 5. The thermal printhead according to claim 3, wherein the IC chip is surface-mounted on the rear surface.

6. The thermal printhead of claim 2 , wherein at least a portion of the inner surface of the recess has a surface roughness greater than that of the support surface.

7. The thermal printhead of claim 6 , wherein all of the inner surfaces of the recess have a surface roughness greater than that of the support surface.

8. The thermal printhead according to claim 6 , wherein the heat dissipation member contains Al.

9. The thermal printhead according to claim 8 , wherein the heat dissipation member has a surface treatment layer that constitutes the support surface.

10. The thermal printhead according to claim 9 , wherein the surface treatment layer is an anodized aluminum layer.

11. The substrate body is a first substrate having a first region that is a part of the main surface and a second region that is a part of the back surface, and supporting the electrode layer and the resistor layer; 2. The thermal printhead according to claim 1, further comprising: a second substrate having a third region that is a part of said main surface and a fourth region that is a part of said back surface, said second substrate having said IC chip mounted thereon.

12. The thermal printhead of claim 11 , wherein the first substrate comprises a ceramic.

13. The thermal printhead of claim 11 , further comprising a connector attached to the second substrate.

14. The thermal printhead according to claim 11 , further comprising a connection member that electrically connects the first substrate and the second substrate.

15. 15. The thermal printhead according to claim 14, wherein the heat dissipation member has a groove portion that accommodates a part of the connection member and extends in a main scanning direction perpendicular to the thickness direction.

16. The thermal printhead according to claim 11 , wherein the driving IC is mounted in the first region of the first substrate.

17. A thermal printer comprising the thermal printhead according to claim 1.