JP2018062136A - Thermal print head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal print head which can inhibit occurrence of a protrusion of an auxiliary electrode layer.SOLUTION: A thermal print head 101 includes: a substrate 1 having a principal surface 11 which is one surface; a glass layer 2 formed on the principal surface 11 of the substrate 1; a connection part 33 of an electrode layer 3 formed on a surface of the glass layer 2 which is opposite to the substrate 1; an auxiliary electrode layer 39 formed on a surface of the connection part 33 which is opposite to the substrate 1; and a resistor layer 4 formed at a principal surface 11 side of the substrate 1. The glass layer 2 is disposed between the connection part 33 and the substrate 1 in an area overlapping with the auxiliary electrode layer 39 when being viewed in a thickness direction of the substrate 1.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a thermal print head.

FIG. 15 is an enlarged cross-sectional view of a main part showing an example of a conventional thermal print head (see, for example, Patent Document 1). In the thermal print head 110 shown in the figure, an electrode layer 3 and a resistor layer 4 are laminated on a substrate 1 made of, for example, Al ₂ O ₃ . The electrode layer 3 includes a common electrode 31 and individual electrodes 35. The thermal print head 110 energizes a portion of the resistor layer 4 between the strip portion 36 of the individual electrode 35 and the strip portion (not shown) of the common electrode 31, thereby causing the portion to generate heat. . Each strip portion of the common electrode 31 is connected to a connecting portion 33 extending in the longitudinal direction. A part of the connecting portion 33 is covered with the auxiliary electrode layer 39. The auxiliary electrode layer 39 is formed of a material having a resistivity lower than that of the connecting portion 33. Generally, the connecting portion 33 is made of resinate Au, and the auxiliary electrode layer 39 is made of Ag. A glass layer 2 such as amorphous glass is formed on the substrate 1 so as to make it easy to stack the electrode layer 3 by removing the surface irregularities. Further, a protective layer 5 for protecting the resistor layer 4, the electrode layer 3, and the auxiliary electrode layer 39 is formed.

  As shown in FIG. 15, the connecting portion 33 of the common electrode 31 is formed so as to cover the end portion of the tip glass layer 26 of the glass layer 2, and the auxiliary electrode layer 39 covers the end portion of the connecting portion 33. It is formed as follows. In this case, a part of the auxiliary electrode layer 39 may rise in the manufacturing process. This is because an adhesion failure occurs at a portion where the substrate 1, the tip glass layer 26 and the connecting portion 33 are in contact with each other, thereby pushing up a part of the auxiliary electrode layer 39. When a part of the auxiliary electrode layer 39 is raised, the surface of the protective layer 5 laminated thereon protrudes from the surroundings. In this case, the protruding portion of the protective layer 5 needs to be scraped or discarded as a defective product.

JP 2012-12183 A

  The present invention has been conceived under the circumstances described above, and an object of the present invention is to provide a thermal print head capable of suppressing the occurrence of swell of the auxiliary electrode layer.

  The thermal print head provided by the present invention is formed on a substrate having a principal surface which is one surface, a glass layer formed on the principal surface of the substrate, and a surface of the glass layer opposite to the substrate. An electrode layer, an auxiliary electrode layer formed on the surface of the electrode layer opposite to the substrate, and a resistor layer formed on the main surface side of the substrate. The glass layer is interposed between the electrode layer and the substrate in a region overlapping the auxiliary electrode layer when viewed in the vertical direction.

  In a preferred embodiment of the present invention, the glass layer includes a belt-shaped partial glaze extending in the main scanning direction and having an arc-shaped cross section, and the resistor layer is disposed at least on the partial glaze. .

  In a preferred embodiment of the present invention, the glass layer further includes a tip glass layer provided downstream in the sub-scanning direction of the partial glaze.

  In a preferred embodiment of the present invention, the tip glass layer extends to the edge of the electrode layer or the outside thereof in the thickness direction of the substrate.

  In a preferred embodiment of the present invention, when viewed in the thickness direction of the substrate, the electrode layer extends to the outside of the edge of the tip glass layer, and the tip glass layer is an end of the auxiliary electrode layer. It extends to the outside of the edge.

  In a preferred embodiment of the present invention, the glass layer further includes a die bonding glaze provided at a position spaced in the main scanning direction with respect to the partial glaze, and is provided on the die bonding glaze. And a driving IC connected to the electrode layer and selectively energizing the resistor layer.

  In a preferred embodiment of the present invention, the glass layer is made of amorphous glass.

In a preferred embodiment of the present invention, the substrate is made of Al ₂ O ₃ .

  In a preferred embodiment of the present invention, the electrode layer contains Au.

  In a preferred embodiment of the present invention, the auxiliary electrode layer is made of a material having a resistivity lower than that of the electrode layer.

  In a preferred embodiment of the present invention, the auxiliary electrode layer contains Ag.

  In a preferred embodiment of the present invention, a second auxiliary electrode layer formed on the surface of the auxiliary electrode layer opposite to the substrate and having a resistivity equal to or lower than the auxiliary electrode layer is provided as the thermal electrode. The print head further includes.

  In a preferred embodiment of the present invention, the electrode layer extends in the sub-scanning direction and is arranged to be separated from each other in the main scanning direction, and connected to the plurality of first belt-like parts. And a common electrode having a connecting portion extending in the main scanning direction and a plurality of individual electrodes each having a second belt-like portion extending in the sub scanning direction and spaced apart from each other in the main scanning direction of the substrate. The auxiliary electrode layer is formed on the connecting portion.

  In a preferred embodiment of the present invention, the resistor layer has a strip shape extending in the main scanning direction, and the first strip portion and the second strip portion are alternately arranged in the main scanning direction. It is arranged to cross the layers.

  In a preferred embodiment of the present invention, the resistor layer is disposed on the side opposite to the substrate with respect to the first strip portion and the second strip portion.

  In a preferred embodiment of the present invention, the thermal print head further includes a protective layer covering the resistor layer, the electrode layer, and the auxiliary electrode layer.

  According to the present invention, in the region overlapping the auxiliary electrode layer, the glass layer is interposed between the electrode layer and the substrate. Therefore, the substrate, the glass layer, and the electrode layer are not in contact with each other in the region. Thereby, it is possible to suppress the adhesion failure from occurring and push up a part of the auxiliary electrode layer, and to suppress the occurrence of the swell of the auxiliary electrode layer.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

1 is a plan view showing a thermal print head according to a first embodiment of the present invention. It is a principal part top view which shows the thermal print head of FIG. It is sectional drawing which follows the III-III line of FIG. It is a principal part expanded sectional view which shows the thermal print head of FIG. It is a principal part top view which shows the thermal print head which concerns on 2nd Embodiment of this invention. It is sectional drawing which follows the VI-VI line in FIG. It is a principal part top view which shows the thermal print head which concerns on 3rd Embodiment of this invention. It is sectional drawing which follows the VIII-VIII line in FIG. It is a principal part top view which shows the thermal print head which concerns on 4th Embodiment of this invention. It is sectional drawing which follows the XX line in FIG. It is a principal part top view which shows the thermal print head which concerns on 5th Embodiment of this invention. It is sectional drawing which follows the XII-XII line | wire in FIG. It is a principal part top view which shows the thermal print head which concerns on 6th Embodiment of this invention. It is sectional drawing which follows the XIV-XIV line | wire in FIG. It is a principal part expanded sectional view which shows an example of the conventional thermal print head.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  1 to 4 show a thermal print head 101 according to a first embodiment of the present invention. FIG. 1 is a plan view showing the thermal print head 101. FIG. 2 is a plan view of the main part showing the thermal print head 101. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is an enlarged cross-sectional view of a main part showing the thermal print head 101. In these drawings, the description will be made assuming that the longitudinal direction (main scanning direction) of the thermal print head 101 is the x direction, the short direction (sub-scanning direction) is the y direction, and the thickness direction is the z direction. The same applies to the following drawings. For convenience of understanding, the protective layer 5 is omitted in FIGS. 1 and 2 (the same applies to FIGS. 5, 7, 9, 11 and 13).

  The thermal print head 101 includes a substrate 1, a glass layer 2, an electrode layer 3, a resistor layer 4, a protective layer 5, and a drive IC 71. The thermal print head 101 is incorporated in a printer that performs printing on thermal paper in order to create, for example, a barcode sheet or a receipt.

The substrate 1 is made of a ceramic such as Al ₂ O ₃ and has a thickness of about 0.6 to 1.0 mm, for example. As shown in FIG. 1, the substrate 1 has a long rectangular shape extending long in the x direction. The substrate 1 has a main surface 11 and a back surface 12 that face opposite sides in the z direction. A glass layer 2, an electrode layer 3, a resistor layer 4, and a protective layer 5 are formed on the main surface 11. A heat sink made of a metal such as Al may be provided on the back surface 12 of the substrate 1.

  Glass layer 2 is formed on main surface 11 of substrate 1 and is made of a glass material such as amorphous glass. The glass layer 2 includes a partial glaze 21, a die bonding glaze 22, an intermediate glass layer 25, and a tip glass layer 26. The glass layer 2 is formed by firing a glass paste after thick film printing.

  The partial glaze 21 has a strip shape extending long in the x direction as shown in FIG. 2, and the sectional shape of the yz plane including the y direction and the z direction is circular as shown in FIGS. The size of the partial glaze 21 is, for example, about 700 μm in the y direction and about 18 to 50 μm in the z direction. The partial glaze 21 is provided in order to press the heat generating portion 41 that is a portion that generates heat in the resistor layer 4 against thermal paper or the like to be printed. The partial glaze 21 may not be provided.

  The die bonding glaze 22 is upstream of the partial glaze 21 in the y direction (sub-scanning direction) (the lower side of the figure in FIGS. 1 and 2 and the right side of the figure in FIGS. 3 and 4). It is in the shape of a strip provided parallel to the partial glaze 21 at a position spaced apart from each other. The die bonding glaze 22 supports a part of the electrode layer 3 and the driving IC 71. The thickness of the die bonding glaze 22 is, for example, about 30 to 50 μm. The softening point of the glass material of the partial glaze 21 and the die bonding glaze 22 is, for example, 800 to 850 ° C. The die bonding glaze 22 may not be provided.

  The intermediate glass layer 25 covers a region sandwiched between the partial glaze 21 and the die bonding glaze 22 in the main surface 11 of the substrate 1. The intermediate glass layer 25 is made of a glass material having a softening point of, for example, about 680 ° C. and a softening point lower than that of the glass material forming the partial glaze 21 and the die bonding glaze 22. The thickness of the intermediate glass layer 25 is, for example, about 2.0 μm. As shown in FIGS. 3 and 4, the tip glass layer 26 covers a part of the region on the downstream side in the y direction with respect to the partial glaze 21 in the main surface 11 of the substrate 1. The tip glass layer 26 has the same material and thickness as the intermediate glass layer 25. The intermediate glass layer 25 and the tip glass layer 26 are provided in order to make it easy to laminate the electrode layer 3 by eliminating the unevenness of the main surface 11 of the substrate 1.

  The electrode layer 3 is for forming a path for energizing the resistor layer 4, and is formed on the glass layer 2 of the main surface 11 of the substrate 1. The electrode layer 3 is made of resinate Au to which, for example, rhodium, vanadium, bismuth, silicon or the like is added as an additive element. The electrode layer 3 is formed by printing a resinate Au paste on a thick film and firing it. The electrode layer 3 may be formed by a thin film forming technique such as sputtering. The electrode layer 3 may be configured by laminating a plurality of Au layers. Although the thickness of the electrode layer 3 is not specifically limited, For example, it is about 0.6-1.2 micrometers. The electrode layer 3 may have a portion formed in a portion other than the main surface 11 of the substrate 1. The electrode layer 3 includes a common electrode 31 and a plurality of individual electrodes 35.

  The common electrode 31 includes a plurality of strip portions 32, a connecting portion 33, and a detour portion 34. As shown in FIGS. 2 and 3, the connecting portion 33 is disposed near the end of the substrate 1 on the downstream side in the y direction, and has a strip shape extending in the x direction. The connecting portion 33 is formed on a part of the partial glaze 21 and the tip glass layer 26, and is formed so that the end portion on the downstream side in the y direction does not protrude from the tip glass layer 26. Further, the end of the connecting portion 33 on the upstream side in the y direction is on the partial glaze 21, and both end portions in the x direction are formed so as not to protrude from the tip glass layer 26. The belt-like portions 32 extend from the connecting portion 33 toward the partial glaze 21 in the y direction, and a plurality of the belt-like portions 32 are arranged at an equal pitch in the x direction. The “band-shaped portion 32” corresponds to the “first band-shaped portion” of the present invention. The bypass portion 34 extends in the y direction from one end of the connecting portion 33 in the x direction.

  The individual electrode 35 is for partially energizing the resistor layer 4 and is a part having a reverse polarity with respect to the common electrode 31. A plurality of individual electrodes 35 are arranged at an equal pitch in the x direction, and each has a strip-like portion 36 and a bonding portion 37. The belt-like portion 36 is a belt-like portion extending in the y direction, and is located between two adjacent belt-like portions 32 on the partial glaze 21. That is, the belt-like portions 36 and the belt-like portions 32 are alternately arranged in the x direction. The “band-shaped portion 36” corresponds to the “second band-shaped portion” of the present invention. The bonding portion 37 is provided at the upstream end of the strip-shaped portion 36 in the y direction.

  As shown in FIGS. 2 to 4, a strip-like auxiliary electrode layer 39 extending in the x direction is formed on the surface of the connecting portion 33 opposite to the substrate 1. The auxiliary electrode layer 39 is provided to suppress heat generation due to the resistance of the connecting portion 33, and is formed of a material (for example, Ag) having a lower resistivity than the connecting portion 33 (electrode layer 3). In the present embodiment, the auxiliary electrode layer 39 includes a first auxiliary electrode layer 391 and a second auxiliary electrode layer 392. The first auxiliary electrode layer 391 is alloyed when stacked on the connecting portion 33 to increase the resistivity. Therefore, the resistance value of the entire current path is reduced by further stacking the second auxiliary electrode layer 392 on the first auxiliary electrode layer 391. In the present embodiment, the first auxiliary electrode layer 391 is an alloy of Au and Ag by laminating Ag on the connecting portion 33 made of resinate Au. Therefore, the second auxiliary electrode layer 392 formed of Ag has a lower resistivity than the first auxiliary electrode layer 391. The first auxiliary electrode layer 391 and the second auxiliary electrode layer 392 are not limited to those formed from the same material. The second auxiliary electrode layer 392 only needs to have a lower resistivity than the first auxiliary electrode layer 391. Although the thickness of the 1st auxiliary electrode layer 391 and the 2nd auxiliary electrode layer 392 is not specifically limited, For example, it is about 10-30 micrometers, respectively. The first auxiliary electrode layer 391 is formed so that each end portion does not protrude from the coupling portion 33, and the second auxiliary electrode layer 392 is formed so that each end portion does not protrude from the first auxiliary electrode layer 391. ing. The “first auxiliary electrode layer 391” and the “second auxiliary electrode layer 392” correspond to the “auxiliary electrode layer” and the “second auxiliary electrode layer” of the present invention, respectively.

  The resistor layer 4 is made of, for example, ruthenium oxide having a higher resistivity than the material constituting the electrode layer 3 and is formed in a strip shape extending in the x direction on the partial glaze 21 of the main surface 11 of the substrate 1. . The resistor layer 4 is formed by printing a paste such as ruthenium oxide on a thick film and then firing the paste. The resistor layer 4 may be formed by a thin film forming technique such as sputtering. The thickness of the resistor layer 4 is not particularly limited, but is, for example, about 0.05 μm to 0.2 μm. The resistor layer 4 is formed above the plurality of strip portions 32 and the plurality of strip portions 36 so as to intersect the plurality of strip portions 32 and the plurality of strip portions 36 at positions near the center of the partial glaze 21. Has been. A portion of the resistor layer 4 sandwiched between the strip portions 32 and the strip portions 36 is a heat generating portion 41. The heat generating portion 41 is a portion that generates heat when being partially energized by the electrode layer 3, and print dots are formed by this heat generation.

  The protective layer 5 is for protecting the resistor layer 4, the electrode layer 3, and the auxiliary electrode layer 39, and is made of, for example, amorphous glass. The softening point of this amorphous glass is, for example, about 700 ° C. As shown in FIG. 3, the protective layer 5 is formed in a region extending from the downstream edge of the substrate 1 (for example, 0.1 to 0.5 mm before the edge) to the vicinity of the center of the die bonding glaze 22 in the y direction. It covers at least the plurality of heat generating portions 41, and covers most of the electrode layer 3 in this embodiment. The protective layer 5 is formed by firing a thick film of glass paste and then baking it. Although the thickness of the protective layer 5 is not specifically limited, For example, it is about 6-8 micrometers. The protective layer 5 may be formed up to the downstream edge of the substrate 1 in the y direction. Further, a second protective layer made of amorphous glass and a plurality of alumina particles having a softening point higher than that of the amorphous glass constituting the protective layer 5 (for example, about 780 ° C.) is provided on the outer side of the protective layer 5. You may make it provide. The second protective layer may be formed in a region extending from the downstream end of the substrate 1 to the vicinity of the center of the intermediate glass layer 25 in the y direction.

  The drive IC 71 fulfills the function of arbitrarily heating any of the plurality of heat generating portions 41 by selectively energizing the plurality of individual electrodes 35. As shown in FIGS. 1 and 3, in the present embodiment, a plurality of driving ICs 71 are arranged on the die bonding glaze 22. In the present embodiment, a part of the electrode layer 3 and the supporting glass layer 27 are interposed between the driving IC 71 and the die bonding glaze 22 (see FIG. 3). As shown in FIG. 2, a plurality of pads 72 are formed on the drive IC 71. The plurality of pads 72 are connected to bonding pads 37 of the plurality of individual electrodes 35 or pads that are part of the electrode layer 3 formed in the die bonding glaze 22 via a plurality of wires 73. As shown in FIG. 1, the drive IC 71 is covered with a sealing resin 82. The sealing resin 82 is made of, for example, black insulating soft resin. 2 and 3, the sealing resin 82 is omitted for the sake of understanding.

  As shown in FIG. 1, the board 1 is provided with a connector 83. The connector 83 is connected to a connector on the printer side when the thermal print head 101 is incorporated into a printer, for example.

  Next, the operation of the thermal print head 101 will be described.

  According to this embodiment, the whole connection part 33 exists on the partial glaze 21 or the front glass layer 26, and each edge part is formed so that it may not protrude from the partial glaze 21 and the front glass layer 26. Therefore, the connecting portion 33 does not contact the substrate 1. Accordingly, there is no portion where the substrate 1, the glass layer 2, and the connecting portion 33 are in contact with each other, so that poor adhesion does not occur at that portion. Thereby, generation | occurrence | production of the swelling of an auxiliary electrode layer can be suppressed.

  Further, according to the present embodiment, the second auxiliary electrode layer 392 made of the same material is further laminated on the first auxiliary electrode layer 391. Therefore, even if the first auxiliary electrode layer 391 is laminated on the connecting portion 33 and alloyed to increase the resistivity, the resistance value of the entire current path can be reduced.

  5 to 14 show other embodiments of the present invention. In these drawings, the same or similar elements as those in the above embodiment are denoted by the same reference numerals as those in the above embodiment.

  5 and 6 show a thermal print head according to a second embodiment of the present invention. 5 is an enlarged plan view, and FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. The thermal print head 102 shown in FIGS. 5 and 6 is different from the thermal print head 101 according to the first embodiment (see FIGS. 1 to 4) in that the second auxiliary electrode layer 392 is not provided.

  When the first auxiliary electrode layer 391 is laminated on the connecting portion 33, it is alloyed to increase the resistivity. However, if the resistance value of the entire current path including the connecting portion 33 and the first auxiliary electrode layer 391 is small, The second auxiliary electrode layer 392 need not be provided.

  Also in this embodiment, the connecting portion 33 does not contact the substrate 1. Accordingly, there is no portion where the substrate 1, the glass layer 2, and the connecting portion 33 are in contact with each other, so that poor adhesion does not occur at that portion. Thereby, generation | occurrence | production of the swelling of the auxiliary electrode layer 39 can be suppressed. Further, since the second auxiliary electrode layer 392 is not provided, the structure can be further simplified.

  7 and 8 show a thermal print head according to a third embodiment of the present invention. FIG. 7 is a plan view of an essential part, and FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. The thermal print head 103 shown in FIGS. 7 and 8 is the thermal print head according to the first embodiment in that the downstream end of the first auxiliary electrode layer 391 in the y direction protrudes from the connecting portion 33. 101 (see FIGS. 1 to 4). The end of the first auxiliary electrode layer 391 on the downstream side in the y direction is formed so as to protrude from the connecting portion 33, but does not protrude from the tip glass layer 26.

  Also in the present embodiment, the entire connecting portion 33 is on the partial glaze 21 or the tip glass layer 26, and each end portion is formed so as not to protrude from the partial glaze 21 and the tip glass layer 26. Therefore, the connecting portion 33 does not contact the substrate 1. Accordingly, there is no portion where the substrate 1, the glass layer 2, and the connecting portion 33 are in contact with each other, so that poor adhesion does not occur at that portion. Thereby, generation | occurrence | production of the swelling of the auxiliary electrode layer 39 can be suppressed.

  9 and 10 show a thermal print head according to a fourth embodiment of the present invention. 9 is a plan view of the main part, and FIG. 10 is a cross-sectional view taken along line XX in FIG. The thermal print head 104 shown in FIGS. 9 and 10 is formed so that the end of the connecting portion 33 on the downstream side in the y direction protrudes from the tip glass layer 26 and covers the end of the tip glass layer 26. This is different from the thermal print head 101 (see FIGS. 1 to 4) according to the first embodiment. The end of the connecting portion 33 on the downstream side in the y direction protrudes from the tip glass layer 26, but the end on the downstream side in the y direction of the first auxiliary electrode layer 391 is downstream of the tip glass layer 26 in the y direction. The end of the is not reached.

  In the present embodiment, poor adhesion may occur at the portion where the substrate 1, the glass layer 2, and the connecting portion 33 are in contact. However, the portion where the substrate 1, the glass layer 2, and the connecting portion 33 are in contact with each other is not covered with the first auxiliary electrode layer 391 (the first auxiliary electrode layer 391 does not extend above the portion). 39 cannot be pushed up. Therefore, the occurrence of the swell of the auxiliary electrode layer 39 can be suppressed.

  11 and 12 show a thermal print head according to a fifth embodiment of the present invention. 11 is a plan view of an essential part, and FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. The thermal print head 105 shown in FIGS. 11 and 12 is formed so that the end of the first auxiliary electrode layer 391 on the downstream side in the y direction protrudes from the tip glass layer 26 and covers the end of the tip glass layer 26. This is different from the thermal print head 101 (see FIGS. 1 to 4) according to the first embodiment.

  In the present embodiment, the entire connecting portion 33 is on the partial glaze 21 or the tip glass layer 26, and each end portion is formed so as not to protrude from the partial glaze 21 and the tip glass layer 26. Therefore, the connecting portion 33 does not contact the substrate 1. Accordingly, there is no portion where the substrate 1, the glass layer 2, and the connecting portion 33 are in contact with each other, so that poor adhesion does not occur at that portion. Thereby, generation | occurrence | production of the swelling of the auxiliary electrode layer 39 can be suppressed.

  13 and 14 show a thermal print head according to a sixth embodiment of the present invention. 13 is a plan view of an essential part, and FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. The thermal print head 106 shown in FIGS. 13 and 14 is the first in that each end of the first auxiliary electrode layer 391, the connecting portion 33, and the tip glass layer 26 is flush with the downstream side in the y direction. This is different from the thermal print head 101 (see FIGS. 1 to 4) according to the embodiment.

  Also in the present embodiment, the entire connecting portion 33 is on the partial glaze 21 or the tip glass layer 26, and each end portion is formed so as not to protrude from the partial glaze 21 and the tip glass layer 26. Therefore, the connecting portion 33 does not contact the substrate 1. Accordingly, there is no portion where the substrate 1, the glass layer 2, and the connecting portion 33 are in contact with each other, so that poor adhesion does not occur at that portion. Thereby, generation | occurrence | production of the swelling of the auxiliary electrode layer 39 can be suppressed.

  The thermal print head according to the present invention is not limited to the above-described embodiment. The specific configuration of each part of the thermal print head according to the present invention can be varied in design in various ways.

101-107: Thermal print head 1: Substrate 11: Main surface 12: Back surface 2: Glass layer 21: Partial glaze 22: Die bonding glaze 25: Intermediate glass layer 26: Front glass layer 27: Support glass layer 3: Electrode layer 31 : Common electrode 32: Strip (first strip)
33: Connecting portion 34: Detour portion 35: Individual electrode 36: Band-shaped portion (first band-shaped portion)
37: Bonding part 39: Auxiliary electrode layer 391: First auxiliary electrode layer 392: Second auxiliary electrode layer 4: Resistor layer 41: Heat generating part 5: Protective layer 71: Drive IC
72: Pad 73: Wire 82: Sealing resin 83: Connector

Claims (16)

A substrate having a main surface which is one surface;
A glass layer formed on the main surface of the substrate;
An electrode layer formed on a surface of the glass layer opposite to the substrate;
An auxiliary electrode layer formed on a surface of the electrode layer opposite to the substrate;
A resistor layer formed on the main surface side of the substrate;
With
In the thickness direction of the substrate, in the region overlapping the auxiliary electrode layer, the glass layer is interposed between the electrode layer and the substrate.
A thermal print head characterized by that. The glass layer is provided with a partial glaze having a strip shape extending in the main scanning direction and an arc-shaped cross section,
The resistor layer is disposed on at least the partial glaze.
The thermal print head according to claim 1. The glass layer further includes a tip glass layer provided on the downstream side in the sub-scanning direction of the partial glaze.
The thermal print head according to claim 2. In the thickness direction view of the substrate, the tip glass layer extends to the edge of the electrode layer or the outside thereof,
The thermal print head according to claim 3. In the thickness direction of the substrate, the electrode layer extends to the outside of the edge of the tip glass layer, and the tip glass layer extends to the outside of the edge of the auxiliary electrode layer,
The thermal print head according to claim 3. The glass layer further includes a die bonding glaze provided at a position separated in the main scanning direction with respect to the partial glaze,
A driving IC provided on the die bonding glaze, connected to the electrode layer, and selectively energizing the resistor layer;
The thermal print head according to claim 2. The glass layer is made of amorphous glass.
The thermal print head according to claim 1. The substrate is made of Al ₂ O ₃ ;
The thermal print head according to claim 1. The electrode layer includes Au;
The thermal print head according to claim 1. The auxiliary electrode layer is made of a material having a smaller resistivity than the electrode layer.
The thermal print head according to claim 1. The auxiliary electrode layer contains Ag.
The thermal print head according to claim 10. A second auxiliary electrode layer formed on the surface of the auxiliary electrode layer opposite to the substrate and having a resistivity equal to or lower than the auxiliary electrode layer;
The thermal print head according to claim 1. The electrode layer is
A plurality of first strips extending in the sub-scanning direction and spaced apart from each other in the main scanning direction, and a common electrode connected to the plurality of first strips and having a coupling portion extending in the main scanning direction;
A plurality of individual electrodes each having a second strip extending in the sub-scanning direction and spaced apart from each other in the main scanning direction of the substrate;
With
The auxiliary electrode layer is formed on the connecting portion.
The thermal print head according to claim 1. The resistor layer has a strip shape extending in the main scanning direction,
The first belt-like portion and the second belt-like portion are arranged so as to cross the resistor layer alternately in the main scanning direction.
The thermal print head according to claim 13. The resistor layer is disposed on the opposite side of the substrate with respect to the first strip portion and the second strip portion.
The thermal print head according to claim 14. A protective layer covering the resistor layer, the electrode layer, and the auxiliary electrode layer;
The thermal print head according to claim 1.

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