JP6930696B2 - Thermal print head - Google Patents

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 printhead 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 an individual electrode 35. The thermal print head 110 generates heat by energizing a portion of the resistor layer 4 sandwiched between the strip-shaped portion 36 of the individual electrode 35 and the strip-shaped portion (not shown) of the common electrode 31. .. Each band-shaped portion of the common electrode 31 is connected to a connecting portion 33 extending in the longitudinal direction. The connecting portion 33 is partially covered with an auxiliary electrode layer 39. The auxiliary electrode layer 39 is made of a material having a resistivity smaller than that of the connecting portion 33. Generally, the connecting portion 33 is made of registered 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 in order to eliminate surface irregularities and facilitate stacking of the electrode layers 3. 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 further covers the end portion of the connecting portion 33. It is formed like this. In this case, a part of the auxiliary electrode layer 39 may rise in the manufacturing process. This is because a poor adhesion occurs at a portion where the substrate 1 is in contact with the tip glass layer 26 and the connecting portion 33, which pushes 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 on the auxiliary electrode layer 39 protrudes from the surroundings. In this case, it is necessary to scrape the protruding portion of the protective layer 5 or dispose of it as a defective product.

Japanese Unexamined Patent Publication No. 2012-12183

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

The thermal printhead provided by the present invention is formed on a substrate having a main surface which is one surface, a glass layer formed on the main surface of the substrate, and a surface of the glass layer opposite to the substrate. The electrode layer is provided with an auxiliary electrode layer formed on a surface of the electrode layer opposite to the substrate, and a resistor layer formed on the main surface side of the substrate, and the thickness of the substrate is provided. In the longitudinal view, the region overlapping the auxiliary electrode layer is characterized in that the glass layer is interposed between the electrode layer and the substrate.

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

In a preferred embodiment of the present invention, the glass layer further includes a tip glass layer provided on the downstream side 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, 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 the end of the auxiliary electrode layer. It extends to the outside of the rim.

In a preferred embodiment of the present invention, the glass layer, with respect to the partial glaze further comprises a die bonding glaze provided at a position separated in the sub scanning direction, provided on the die bonding glaze It is further provided with a drive IC which is connected to the electrode layer and selectively energizes 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 invention, the electrode layer comprises 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, the thermal is formed on the second auxiliary electrode layer which is formed on the surface of the auxiliary electrode layer opposite to the substrate and whose resistivity is equal to or lower than the auxiliary electrode layer. The print head is further equipped.

In a preferred embodiment of the present invention, the electrode layer is connected to a plurality of first strips extending in the sub-scanning direction and spaced apart from each other in the main scanning direction, and a plurality of the first strips. A common electrode having a connecting portion extending in the main scanning direction and a plurality of individual electrodes each having a second band-shaped portion extending in the sub-scanning direction and arranged apart from each other in the main scanning direction of the substrate are provided. The auxiliary electrode layer is formed in the connecting portion.

In a preferred embodiment of the present invention, the resistor layer has a band shape extending in the main scanning direction, and the first band-shaped portion and the second band-shaped portion alternately alternate in the main scanning direction of the resistor. Arranged so as to intersect the layers.

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

In a preferred embodiment of the invention, the thermal printhead further comprises 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, a glass layer is interposed between the electrode layer and the substrate. Therefore, the substrate, the glass layer, and the electrode layer do not come into contact with each other in the region. As a result, it is possible to suppress the occurrence of poor adhesion and pushing up a part of the auxiliary electrode layer, and to suppress the occurrence of swelling of the auxiliary electrode layer.

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

It is a top view which shows the thermal print head which concerns on 1st Embodiment of this invention. It is a main part plan view which shows the thermal print head of FIG. It is sectional drawing which follows the line III-III of FIG. FIG. 5 is an enlarged cross-sectional view of a main part showing the thermal print head of FIG. It is a main part plan view which shows the thermal print head which concerns on 2nd Embodiment of this invention. FIG. 5 is a cross-sectional view taken along the line VI-VI in FIG. It is a main part plan view which shows the thermal print head which concerns on 3rd Embodiment of this invention. FIG. 7 is a cross-sectional view taken along the line VIII-VIII in FIG. It is a main part plan view which shows the thermal print head which concerns on 4th Embodiment of this invention. 9 is a cross-sectional view taken along the line XX in FIG. It is a main part plan view which shows the thermal print head which concerns on 5th Embodiment of this invention. 11 is a cross-sectional view taken along the line XII-XII in FIG. It is a main part plan view which shows the thermal print head which concerns on 6th Embodiment of this invention. FIG. 3 is a cross-sectional view taken along the line XIV-XIV in FIG. It is an enlarged sectional view of the main part 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 the thermal print head 101 according to the 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 a main part showing the thermal print head 101. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. FIG. 4 is an enlarged cross-sectional view of a main part showing the thermal print head 101. In these figures, the longitudinal direction (main scanning direction) of the thermal print head 101 is defined as the x direction, the lateral direction (secondary scanning direction) is defined as the y direction, and the thickness direction is defined as the z direction. The same applies to the following figure. 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 prints on thermal paper to produce, for example, a barcode sheet or a receipt.

The substrate 1 is made of, for example, _{a ceramic such as Al 2} O _3, and has a thickness of, for example, about 0.6 to 1.0 mm. As shown in FIG. 1, the substrate 1 has an elongated rectangular shape extending in the x direction. The substrate 1 has a main surface 11 and a back surface 12 facing 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 radiating plate made of a metal such as Al may be provided on the back surface 12 of the substrate 1.

The glass layer 2 is formed on the main surface 11 of the 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 printing a thick film of glass paste and then firing the glass paste.

As shown in FIG. 2, the partial glaze 21 has a strip shape extending in the x direction, and as shown in FIGS. 3 and 4, the cross-sectional shape of the yz plane including the y direction and the z direction is arcuate. 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 to press the heat generating portion 41, which is a heat generating portion of the resistor layer 4, against the thermal paper or the like to be printed. The partial glaze 21 may not be provided.

The die bonding glaze 22 is on the upstream side in the y direction (sub-scanning direction) with respect to the partial glaze 21 (the lower side in the drawings in FIGS. 1 and 2 and the right side in the drawings in FIGS. 3 and 4). It has a strip shape provided in parallel with the partial glaze 21 at a position separated from the glaze 21. 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 points of the glass materials of the partial glaze 21 and the die bonding glaze 22 are, for example, 800 to 850 ° C. The die bonding glaze 22 may not be provided.

The intermediate glass layer 25 covers a region of the main surface 11 of the substrate 1 sandwiched between the partial glaze 21 and the die bonding glaze 22. The intermediate glass layer 25 is made of a glass material having a softening point of, for example, about 680 ° C., which is lower than 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 main surface 11 of the substrate 1 on the downstream side in the y direction with respect to the partial glaze 21. 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 eliminate the unevenness of the main surface 11 of the substrate 1 and facilitate the lamination of the electrode layer 3.

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 registered 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 thick film of the resinate Au paste and then firing the paste. The electrode layer 3 may be formed by a thin film forming technique such as sputtering. The electrode layer 3 may be formed by laminating a plurality of Au layers. The thickness of the electrode layer 3 is not particularly limited, but is, for example, about 0.6 to 1.2 μm. The electrode layer 3 may have a portion formed on 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 strips 32, a connecting portion 33, and a bypass portion 34. As shown in FIGS. 2 and 3, the connecting portion 33 is arranged near the end portion 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 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 portion of the connecting portion 33 on the upstream side in the y direction is on the partial glaze 21, and both ends in the x direction are also formed so as not to protrude from the tip glass layer 26. A plurality of strip-shaped portions 32 extend from the connecting portion 33 toward the partial glaze 21 in the y direction, and are arranged at equal pitches in the x direction. The "belt-shaped portion 32" corresponds to the "first strip-shaped portion" of the present invention. The detour 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 portion having opposite polarity to the common electrode 31. A plurality of individual electrodes 35 are arranged at equal pitches in the x direction, and each has a band-shaped portion 36 and a bonding portion 37. The band-shaped portion 36 is a band-shaped portion extending in the y direction, and is located between two adjacent strip-shaped portions 32 on the partial glaze 21. That is, the strip-shaped portion 36 and the strip-shaped portion 32 are alternately arranged in the x direction. The "belt-shaped portion 36" corresponds to the "second strip-shaped portion" of the present invention. The bonding portion 37 is provided at the upstream end portion of the strip-shaped portion 36 in the y direction.

As shown in FIGS. 2 to 4, a band-shaped 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 resistivity smaller than that of 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 laminated on the connecting portion 33 to increase the resistivity. Therefore, by further laminating the second auxiliary electrode layer 392 on the first auxiliary electrode layer 391, the resistance value of the entire current path is reduced. 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 registered Au. Therefore, the resistivity of the second auxiliary electrode layer 392 formed by Ag is smaller than that of 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 of the same material. The resistivity of the second auxiliary electrode layer 392 may be smaller than that of the first auxiliary electrode layer 391. The thickness of the first auxiliary electrode layer 391 and the second auxiliary electrode layer 392 is not particularly limited, but is, for example, about 10 to 30 μm, respectively. The first auxiliary electrode layer 391 is formed so that each end does not protrude from the connecting portion 33, and the second auxiliary electrode layer 392 is formed so that each end 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 resistivity higher than that of the material constituting the electrode layer 3, and is formed in a band 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 thick film of a paste such as ruthenium oxide 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 on the upper side of the plurality of strips 32 and the plurality of strips 36 at a position near the center of the partial glaze 21 so as to intersect the plurality of strips 32 and the plurality of strips 36, respectively. Has been done. A portion of the resistor layer 4 sandwiched between each band-shaped portion 32 and each band-shaped portion 36 is a heat generating portion 41. The heat generating portion 41 is a portion that generates heat when 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 front of 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 a plurality of heat generating portions 41, and in the present embodiment, covers most of the electrode layer 3. The protective layer 5 is formed by printing a thick film of the glass paste and then firing the glass paste. The thickness of the protective layer 5 is not particularly limited, but is, for example, about 6 to 8 μm. The protective layer 5 may be formed up to the downstream edge of the substrate 1 in the y direction. Further, on the outer side of the protective layer 5, a second protective layer composed of an amorphous glass having a softening point higher than that of the amorphous glass constituting the protective layer 5 (for example, about 780 ° C.) and a plurality of alumina particles is provided. It may be provided. The second protective layer may be formed in a region extending from the downstream end portion of the substrate 1 to the vicinity of the center of the intermediate glass layer 25 in the y direction.

The drive IC 71 functions to arbitrarily generate heat in any of the plurality of heat generating units 41 by selectively energizing the plurality of individual electrodes 35. As shown in FIGS. 1 and 3, in this embodiment, a plurality of drive 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 the bonding portions 37 of the plurality of individual electrodes 35 or the pads which are a part of the electrode layer 3 formed on the die bonding glaze 22 via the 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, a black insulating soft resin. In addition, in FIG. 2 and FIG. 3, the sealing resin 82 is omitted for convenience of understanding.

Further, as shown in FIG. 1, a connector 83 is provided on the substrate 1. The connector 83 is connected to the 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 the present embodiment, the connecting portion 33 is entirely 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 come into contact with the substrate 1. Therefore, since there is no portion where the substrate 1 is in contact with the glass layer 2 and the connecting portion 33, poor adhesion does not occur at that portion. As a result, it is possible to suppress the occurrence of swelling of the auxiliary electrode layer.

Further, according to the present embodiment, the second auxiliary electrode layer 392 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 figures, the same or similar elements as those in the above embodiment are designated by the same reference numerals as those in the above embodiment.

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

The first auxiliary electrode layer 391 is alloyed when laminated on the connecting portion 33 to increase the resistivity, but if the resistance value of the entire current path in which the connecting portion 33 and the first auxiliary electrode layer 391 are combined is small. , It is not necessary to provide the second auxiliary electrode layer 392.

Also in this embodiment, the connecting portion 33 does not come into contact with the substrate 1. Therefore, since there is no portion where the substrate 1 is in contact with the glass layer 2 and the connecting portion 33, poor adhesion does not occur at that portion. As a result, it is possible to suppress the occurrence of swelling of the auxiliary electrode layer 39. Further, since the second auxiliary electrode layer 392 is not provided, the structure can be further simplified.

7 and 8 show a thermal printhead according to a third embodiment of the present invention. FIG. 7 is a plan view of the main part, and FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. The thermal printhead 103 shown in FIGS. 7 and 8 is the thermal printhead according to the first embodiment in that the end portion of the first auxiliary electrode layer 391 on the downstream side in the y direction protrudes from the connecting portion 33. It is different from 101 (see FIGS. 1 to 4). The end portion 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 connecting portion 33 is entirely 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 come into contact with the substrate 1. Therefore, since there is no portion where the substrate 1 is in contact with the glass layer 2 and the connecting portion 33, poor adhesion does not occur at that portion. As a result, it is possible to suppress the occurrence of swelling of the auxiliary electrode layer 39.

9 and 10 show a thermal printhead according to a fourth embodiment of the present invention. 9 is a plan view of a 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 portion of the connecting portion 33 on the downstream side in the y direction protrudes from the tip glass layer 26 and covers the end portion of the tip glass layer 26. , It 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 is formed so as to protrude from the tip glass layer 26, but the end of the first auxiliary electrode layer 391 on the downstream side in the y direction is on the downstream side of the tip glass layer 26 in the y direction. Has not reached the end of.

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

11 and 12 show a thermal printhead according to a fifth embodiment of the present invention. FIG. 11 is a plan view of a main part, and FIG. 12 is a cross-sectional view taken along the line XII-XII in FIG. The thermal print head 105 shown in FIGS. 11 and 12 is formed so that the end portion 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 portion of the tip glass layer 26. In that respect, it is different from the thermal print head 101 (see FIGS. 1 to 4) according to the first embodiment.

In the present embodiment, the connecting portion 33 is entirely 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 come into contact with the substrate 1. Therefore, since there is no portion where the substrate 1 is in contact with the glass layer 2 and the connecting portion 33, poor adhesion does not occur at that portion. As a result, it is possible to suppress the occurrence of swelling of the auxiliary electrode layer 39.

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

Also in the present embodiment, the connecting portion 33 is entirely 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 come into contact with the substrate 1. Therefore, since there is no portion where the substrate 1 is in contact with the glass layer 2 and the connecting portion 33, poor adhesion does not occur at that portion. As a result, it is possible to suppress the occurrence of swelling of the auxiliary electrode layer 39.

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 freely redesigned.

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: Tip glass layer 27: Support glass layer 3: Electrode layer 31 : Common electrode 32: Band-shaped part (first band-shaped part)
33: Connecting part 34: Bypass part 35: Individual electrode 36: Band-shaped part (first band-shaped part)
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: Encapsulating resin 83: Connector

Claims (14)

A substrate having a main surface, which is one surface,
A glass layer formed on the main surface of the substrate and
An electrode layer formed on the surface of the glass layer opposite to the substrate,
An auxiliary electrode layer formed on the surface of the electrode layer opposite to the substrate,
The resistor layer formed on the main surface side of the substrate and
Is equipped with
In the area where the auxiliary electrode layer overlaps in the thickness direction of the substrate, the glass layer is interposed between the electrode layer and the substrate.
The glass layer is
Partial glaze with a strip-shaped and arc-shaped cross section extending in the main scanning direction,
The tip glass layer provided on the downstream side in the sub-scanning direction of the partial glaze,
With more
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.
A thermal print head that features that. The tip glass layer has a lower softening point than the partial glaze.
The thermal print head according to claim 1. The resistor layer is arranged at least on the partial glaze.
The thermal printhead according to claim 1 or 2. The glass layer further includes die bonding glaze provided at a position separated from the partial glaze in the sub-scanning direction.
A drive IC provided on the die bonding glaze, connected to the electrode layer, and selectively energizing the resistor layer is further provided.
The thermal print head according to any one of claims 1 to 3. The glass layer is made of amorphous glass.
The thermal print head according to any one of claims 1 to 4. The substrate is made of Al ₂ O ₃ .
The thermal print head according to any one of claims 1 to 5. The electrode layer contains Au.
The thermal print head according to any one of claims 1 to 6. The auxiliary electrode layer is made of a material having a resistivity lower than that of the electrode layer.
The thermal print head according to any one of claims 1 to 7. The auxiliary electrode layer contains Ag.
The thermal print head according to claim 8. 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 that of the auxiliary electrode layer is further provided.
The thermal print head according to any one of claims 1 to 9. The electrode layer is
A common electrode having a plurality of first band-shaped portions extending in the sub-scanning direction and arranged apart from each other in the main scanning direction, and a connecting portion connected to the plurality of the first strip-shaped portions and extending in the main scanning direction.
A plurality of individual electrodes each having a second strip extending in the sub-scanning direction and arranged apart from each other in the main scanning direction of the substrate.
Is equipped with
The auxiliary electrode layer is formed in the connecting portion.
The thermal print head according to any one of claims 1 to 10. The resistor layer has a strip shape extending in the main scanning direction.
The first strip and the second strip are arranged alternately in the main scanning direction so as to intersect the resistor layer.
The thermal print head according to claim 11. The resistor layer is arranged on the side opposite to the substrate with respect to the first strip-shaped portion and the second strip-shaped portion.
The thermal print head according to claim 12. A protective layer that covers the resistor layer, the electrode layer, and the auxiliary electrode layer is further provided.
The thermal print head according to any one of claims 1 to 13.

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