JP2022059793A - Thermal print head and method for manufacture thereof and thermal printer - Google Patents

Abstract

To provide a thermal print head which improves print characteristics onto a print medium and a method for manufacture of the thermal print head, and further, provide a thermal printer comprising the thermal print head.SOLUTION: A thermal print head comprises: a heat accumulation layer; a first electrode part on the heat accumulation layer; a heat element on the first electrode part; a second electrode part on the heat element; and a protective film which covers the second electrode part and the heat element.SELECTED DRAWING: Figure 1

Description

The present embodiment relates to a thermal print head, a method for manufacturing the same, and a thermal printer.

The thermal print head includes, for example, a large number of heat generating portions arranged in the main scanning direction on the head substrate. Each heat generating portion is formed by laminating a common electrode and an individual electrode with their ends facing each other so as to expose a part of the resistor layer formed on the head substrate via a glaze layer. Has been done. By energizing between the common electrode and the individual electrodes, the exposed portion (heat generating portion) of the resistor layer generates heat due to Joule heat. By transferring the heat to a printing medium (bar code sheet, thermal paper for producing a receipt, etc.), printing is performed on the printing medium.

To form the common electrode, the individual electrode, and the like, an electrode pattern is formed by screen-printing a paste using a metal such as gold or silver.

In recent years, traceability has been emphasized, and all kinds of information such as factory-specific symbols, date of manufacture, expiration date, etc. have been written on print media such as labels and receipts, and in food products, nutrition facts are displayed. The amount of printed information and the amount of labels printed in the logistics field are on the rise, such as making it mandatory and changing allergy labeling.

In order to enable a large amount of printing, which is on the increase, it is necessary for the thermal print head to print information on a print medium at high speed and with high definition. In order to print at high speed and with high definition, it is important to evenly distribute the heat generated by energization or to narrow the pitch between the electrodes (equal to the pitch between the heat generation resistance parts). In the electrode formation process in a thermal print head that can print at high speed and with high definition, the electrodes are integrated at a higher density, so short circuits and disconnections occur frequently, and there is a concern that printing characteristics such as printing efficiency on the printing medium will deteriorate. ..

Japanese Unexamined Patent Publication No. 2000-141729

One aspect of the present embodiment provides a thermal printhead that improves print characteristics on a print medium. Further, another aspect of the present embodiment provides a method for manufacturing the thermal print head. Further, another aspect of the present embodiment provides a thermal printer provided with the thermal printhead.

In this embodiment, by providing electrodes above and below the heat storage layer, it is possible to evenly disperse the heat generated and to narrow the pitch between the electrodes, thereby improving the printing characteristics on the printing medium. be able to. One aspect of this embodiment is as follows.

One embodiment of the present embodiment includes a heat storage layer, a first electrode portion on the heat storage layer, a heat generation resistor on the first electrode portion, and a second electrode portion on the heat storage resistor. A thermal print head including the second electrode portion and a protective film covering the heat generation resistor.

Further, another aspect of the present embodiment is a thermal printer provided with the thermal print head.

Further, in another aspect of the present embodiment, a heat storage layer is formed, a plurality of first electrodes are formed on the heat storage layer, and an insulating layer covering a part of each of the plurality of first electrodes is provided. The plurality of first electrodes are formed to form a heat-generating resistor that covers a region not covered by the insulating layer, and a plurality of second electrodes are formed on the heat-generating resistor and on the insulating layer. , A method of manufacturing a thermal print head, which forms a protective film covering the plurality of second electrodes, the heat generation resistor, and the insulating layer.

Further, in another aspect of the present embodiment, a heat storage layer is formed, a plurality of first electrodes are formed on the heat storage layer, and a heat generation resistor covering the plurality of first electrodes is formed. A plurality of second electrodes and a plurality of third electrodes different from the second electrodes are formed on the heat generation resistor and the heat storage layer, and the plurality of second electrodes and the plurality of third electrodes are formed. , And a protective film covering the heat generation resistor is formed, and the second electrode and the third electrode are alternately arranged, which is a method for manufacturing a thermal print head.

According to the present embodiment, it is possible to provide a thermal print head that improves printing characteristics on a printing medium. Further, it is possible to provide a method for manufacturing the thermal print head. Further, it is possible to provide a thermal printer provided with the thermal print head.

FIG. 1 is a partial perspective view illustrating the thermal print head according to the first embodiment. FIG. 2 is a partial cross-sectional view taken along the line AA'of FIG. 1 in the main scanning direction X. FIG. 3 is a partial cross-sectional view taken along the line BB'of FIG. 1 in the sub-scanning direction Y. FIG. 4 is a partial perspective view illustrating a method for manufacturing a thermal print head according to the first embodiment (No. 1). FIG. 5 is a partial cross-sectional view taken along the line AA'of FIG. 4 in the main scanning direction X. FIG. 6 is a partial cross-sectional view taken along the line BB'of FIG. 4 in the sub-scanning direction Y. FIG. 7 is a partial perspective view illustrating the method for manufacturing the thermal print head according to the first embodiment (No. 2). FIG. 8 is a partial cross-sectional view taken along the line AA'of FIG. 7 in the main scanning direction X. FIG. 9 is a partial cross-sectional view taken along the line BB'of FIG. 7 in the sub-scanning direction Y. FIG. 10 is a partial perspective view illustrating a method for manufacturing a thermal print head according to the first embodiment (No. 3). FIG. 11 is a partial cross-sectional view taken along the line AA'of FIG. 10 in the main scanning direction X. FIG. 12 is a partial cross-sectional view taken along the line BB'of FIG. 10 in the sub-scanning direction Y. FIG. 13 is a partial perspective view illustrating a method for manufacturing a thermal print head according to the first embodiment (No. 4). FIG. 14 is a partial cross-sectional view taken along the line AA'of FIG. 13 in the main scanning direction X. FIG. 15 is a partial cross-sectional view taken along the line BB'of FIG. 13 in the sub-scanning direction Y. FIG. 16 is a partial perspective view illustrating a method for manufacturing a thermal print head according to the first embodiment (No. 5). FIG. 17 is a partial cross-sectional view taken along the line AA'of FIG. 16 in the main scanning direction X. FIG. 18 is a partial cross-sectional view taken along the line BB'of FIG. 16 in the sub-scanning direction Y. FIG. 19 is a partial perspective view illustrating the thermal print head according to the second embodiment. FIG. 20 is a partial cross-sectional view taken along the line AA'of FIG. 19 in the main scanning direction X. FIG. 21 is a partial cross-sectional view taken along the line BB'of FIG. 19 in the sub-scanning direction Y. FIG. 22 is a partial perspective view illustrating a method for manufacturing a thermal print head according to a second embodiment (No. 1). FIG. 23 is a partial cross-sectional view taken along the line AA'of FIG. 22 in the main scanning direction X. FIG. 24 is a partial cross-sectional view taken along the line BB'of FIG. 22 in the sub-scanning direction Y. FIG. 25 is a partial perspective view illustrating a method for manufacturing a thermal print head according to a second embodiment (No. 2). FIG. 26 is a partial cross-sectional view taken along the line AA'of FIG. 25 in the main scanning direction X. FIG. 27 is a partial cross-sectional view taken along the line BB'of FIG. 25 in the sub-scanning direction Y. FIG. 28 is a partial perspective view illustrating the method for manufacturing the thermal print head according to the second embodiment (No. 3). FIG. 29 is a partial cross-sectional view taken along the line AA'of FIG. 28 in the main scanning direction X. FIG. 30 is a partial cross-sectional view taken along the line BB'of FIG. 28 in the sub-scanning direction Y. FIG. 31 is a partial perspective view illustrating a method for manufacturing a thermal print head according to a second embodiment (No. 4). FIG. 32 is a partial cross-sectional view taken along the line AA'of FIG. 31 in the main scanning direction X. FIG. 33 is a partial cross-sectional view taken along the line BB'of FIG. 31 in the sub-scanning direction Y. FIG. 34 is a partial cross-sectional view of a modification 1 of the thermal print head according to the first embodiment in the main scanning direction X. FIG. 35 is a partial cross-sectional view of a modification 2 of the thermal print head according to the first embodiment in the main scanning direction X. FIG. 36 is a partial cross-sectional view of a modification 3 of the thermal print head according to the first embodiment in the main scanning direction X. FIG. 37 is a partial cross-sectional view of a modification 1 of the thermal print head according to the second embodiment in the main scanning direction X. FIG. 38 is a partial cross-sectional view of a modification 2 of the thermal print head according to the second embodiment in the main scanning direction X. FIG. 39 is a partial cross-sectional view of a modification 3 of the thermal print head according to the second embodiment in the main scanning direction X. FIG. 40 is a cross-sectional view illustrating the thermal print head according to the present embodiment.

Next, the present embodiment will be described with reference to the drawings. In the description of the drawings described below, the same or similar parts are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic and the relationship between the thickness of each component and the plane dimensions is different from the actual one. Therefore, the specific thickness and dimensions should be determined in consideration of the following explanation. In addition, it goes without saying that parts of the drawings having different dimensional relationships and ratios are included.

Further, the ordinal numbers "first", "second", and "third" used in the present specification and the like are added to avoid confusion of the components, and are not limited numerically.

Further, the embodiments shown below exemplify devices and methods for embodying the technical idea, and do not specify the material, shape, structure, arrangement, etc. of each component. This embodiment can be modified in various ways within the scope of the claims.

A specific embodiment of the present embodiment is as follows.

<1> The heat storage layer, the first electrode portion on the heat storage layer, the heat generation resistor on the first electrode portion, the second electrode portion on the heat generation resistor, and the second electrode. A thermal print head comprising a portion and a protective film covering the heat generation resistor.

<2> The first electrode portion has a plurality of first electrodes, the second electrode portion has a plurality of second electrodes, and one of the plurality of first electrodes has a plurality of first electrodes. The thermal printhead according to <1>, which is superimposed on one of the plurality of second electrodes and is superimposed on the other one of the plurality of second electrodes.

<3> The thermal print head according to <2>, wherein the width of the first electrode is smaller than the width of the second electrode in the main scanning direction.

<4> In the main scanning direction, the width of the region where one of the plurality of first electrodes and one of the plurality of second electrodes are overlapped is one of the plurality of first electrodes and the plurality of the above. The thermal printhead according to <2> or <3>, which has the same width as the region on which the other one of the second electrodes of the above overlaps.

<5> One of the first electrode and the second electrode is an individual electrode, and the other of the first electrode and the second electrode is a common electrode and is the common electrode. The item according to any one of <2> to <4>, wherein each of the plurality of first electrodes or the plurality of second electrodes is a comb tooth portion and is connected to the common portion of the common electrode. Thermal print head.

<6> Further, it has an insulating layer located between a part of the first electrode portion and a part of the second electrode portion, and has the first electrode portion and the second electrode portion. The thermal print head according to any one of <2> to <5>, wherein at least one of the insulating layer and the heat generation resistor is provided between the two.

<7> The first electrode portion has a plurality of first electrodes, and the second electrode portion includes a plurality of second electrodes and a plurality of third electrodes different from the second electrode. The thermal print head according to <1>, wherein the second electrode and the third electrode are arranged alternately.

<8> The above-mentioned <7>, wherein one of the plurality of first electrodes is superimposed on one of the plurality of second electrodes and is superimposed on one of the plurality of third electrodes. Thermal print head.

<9> The thermal printhead according to <7> or <8>, wherein the width of the first electrode is larger than the width of the second electrode and the width of the third electrode in the main scanning direction.

<10> One of the second electrode and the third electrode is an individual electrode, and the other of the second electrode and the third electrode is a common electrode and is the common electrode. The item according to any one of <7> to <9>, wherein each of the plurality of second electrodes or the plurality of third electrodes is a comb tooth portion and is connected to the common portion of the common electrode. Thermal print head.

<11> A thermal printer including the thermal print head according to any one of <1> to <10>.

<12> A heat storage layer is formed, a plurality of first electrodes are formed on the heat storage layer, an insulating layer covering a part of each of the plurality of first electrodes is formed, and the plurality of first electrodes are formed. In the electrodes, a heat generation resistor that covers a region not covered by the insulating layer is formed, and a plurality of second electrodes are formed on the heat generation resistor and on the insulating layer, and the plurality of second electrodes, A method for manufacturing a thermal print head, which forms a protective film that covers the heat generation resistor and the insulating layer.

<13> One of the first electrode and the second electrode is an individual electrode, and the other of the first electrode and the second electrode is a common electrode and is the common electrode. The method for manufacturing a thermal printhead according to <12>, wherein each of the plurality of first electrodes or the plurality of second electrodes is a comb tooth portion and is connected to a common portion of the common electrode.

<14> A heat storage layer is formed, a plurality of first electrodes are formed on the heat storage layer, a heat generation resistor covering the plurality of first electrodes is formed, and the heat storage resistor and the heat storage layer are covered. A plurality of second electrodes and a plurality of third electrodes different from the second electrode are formed, and the plurality of second electrodes, the plurality of third electrodes, and the heat generating resistor are covered with protection. A method for manufacturing a thermal print head, in which a film is formed and the second electrode and the third electrode are alternately arranged.

<15> One of the second electrode and the third electrode is an individual electrode, and the other of the second electrode and the third electrode is a common electrode and is the common electrode. The method for manufacturing a thermal printhead according to <14>, wherein each of the plurality of second electrodes or the plurality of third electrodes is a comb tooth portion and is connected to a common portion of the common electrode.

<16> One of the plurality of first electrodes is superimposed on one of the plurality of second electrodes and is superimposed on the other one of the plurality of second electrodes, <12> or. The method for manufacturing a thermal print head according to <13>.

<17> The thermal print head according to any one of <12>, <13>, and <16>, wherein the width of the first electrode is smaller than the width of the second electrode in the main scanning direction. Production method.

<18> In the main scanning direction, the width of the region where one of the plurality of first electrodes and one of the plurality of second electrodes are overlapped is one of the plurality of first electrodes and the plurality of the above. The thermal print head according to any one of <12>, <13>, <16>, and <17>, which has the same width as the region on which the other one of the second electrodes of the above is superimposed. Manufacturing method.

<19> One of the plurality of first electrodes is superimposed on one of the plurality of second electrodes and is superimposed on one of the plurality of third electrodes, <14> or <15>. > The method for manufacturing a thermal printhead.

<20> In the main scanning direction, the width of the first electrode is larger than the width of the second electrode and the width of the third electrode, any one of <14>, <15>, and <19>. The method for manufacturing a thermal printhead according to the section.

<Thermal print head>
(Embodiment 1)
The thermal print head according to this embodiment will be described with reference to the drawings.

FIG. 1 is a partial perspective view showing a thermal print head. FIG. 2 is a partial cross-sectional view taken along the line AA'of FIG. 1 in the main scanning direction X. FIG. 3 is a partial cross-sectional view taken along the line BB'of FIG. 1 in the sub-scanning direction Y. 1 to 3 show a part of a thermal print head (corresponding to one thermal print head), and in the present embodiment, this one thermal print head is a piece-shaped thermal print head 100A. .. The thermal print head 100A includes a heat storage layer 33, a first electrode portion on the heat storage layer 33, a heat generation resistor 40 on the first electrode portion, a second electrode portion on the heat storage resistor 40, and a second electrode portion. It is provided with at least a protective film 34 that covers the electrode portion of 2 and the heat generation resistor 40. Specifically, the thermal print head 100A includes a substrate 15, a heat storage layer 33 on the substrate 15, a plurality of first electrodes 31 included in a first electrode portion on the heat storage layer 33, and a plurality of first electrodes. An insulating layer 35 that covers a part of each of the electrodes 31 of the above, a heat generating resistor 40 that covers a region not covered by the insulating layer 35 in the plurality of first electrodes 31, and a heat generating resistor 40 and an insulating layer 35. A plurality of second electrodes 32 included in the above second electrode portion, a plurality of second electrodes 32, a heat generating resistor 40, and a protective film 34 covering the insulating layer 35 are provided. Further, one of the first electrode 31 and the second electrode 32 is an individual electrode, and the other of the first electrode 31 and the second electrode 32 is a common electrode. For example, in the present embodiment, the first electrode The electrode 31 of 1 is an individual electrode, and the other of the second electrodes 32 is a common electrode. The heat generation resistor 40 includes a plurality of heat generation resistance portions 41 that generate heat due to the current flowing through the individual electrodes and the common electrode. In the plurality of heat generation resistance portions 41, each heat generation resistance portion 41 is independently formed between the first electrode 31 and the second electrode 32. In FIG. 1, a plurality of heat generation resistance portions 41 are omitted. The plurality of heat generation resistance portions 41 are arranged linearly on the heat storage layer 33. Further, in FIG. 1, the protective film 34 is omitted for ease of understanding.

In the present embodiment, the direction in which the plurality of heat generation resistance portions 41 extend linearly is the main scanning direction X, the direction perpendicular to the main scanning direction X and parallel to the upper surface of the substrate 15 is the sub-scanning direction Y. The direction corresponding to the thickness of the substrate 15 is defined as the thickness direction Z. In other words, the thickness direction Z is a direction perpendicular to each of the main scanning direction X and the sub-scanning direction Y.

The substrate 15 is made of a ceramic or a single crystal semiconductor. As the ceramic, for example, alumina or the like can be used. As the single crystal semiconductor, for example, silicon or the like can be used. From the viewpoint of heat dissipation, it is preferable to use alumina having a relatively large thermal conductivity for the substrate 15.

A heat storage layer 33 (also referred to as a glaze layer) having a function of accumulating heat is laminated on a substrate 15 made of an alumina substrate or the like. The heat storage layer 33 stores heat generated from the heat generation resistance unit 41 described later. An insulating material can be used for the heat storage layer 33, and for example, silicon oxide or silicon nitride, which are the main components of glass, can be used. The dimension of the heat storage layer 33 in the thickness direction Z is not particularly limited, and is, for example, 30 to 80 μm, preferably 40 to 60 μm.

On the heat storage layer 33, a plurality of first electrodes 31 which are individual electrodes formed from the metal paste are provided. The first electrode 31 is obtained by applying a metal paste by a screen printing method or the like to form an electrode pattern.

As the metal paste, for example, a paste containing metal particles such as copper, silver, palladium, iridium, platinum, and gold can be used. Copper, silver, platinum, and gold are preferable from the viewpoint of metal characteristics and ionization tendency, and copper and silver are more preferable from the viewpoint of metal characteristics, ionization tendency, and cost reduction. Further, the solvent contained in the metal paste has a function of uniformly dispersing the metal particles, and for example, an ester solvent, a ketone solvent, a glycol ether solvent, an aliphatic solvent, an alicyclic solvent, and an aromatic. Examples thereof include, but are not limited to, one type or a mixture of two or more types of a solvent, an alcohol solvent, water and the like.

Examples of the ester solvent include ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, amyl acetate, ethyl lactate, dimethyl carbonate and the like. Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone benzene, diisobutyl ketone, diacetone alcohol, isophorone, cyclohexanenone and the like. Examples of the glycol ether-based solvent include acetates of these monoethers such as ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, and ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether. , Propylene glycol monomethyl ether, propylene glycol monoethyl ether and the like, and acetates of these monoethers.

Examples of the aliphatic solvent include n-heptane, n-hexane, cyclohexane, methylcyclohexane, ethylcyclohexane and the like. Examples of the alicyclic solvent include methylcyclohexane, ethylcyclohexane, cyclohexane and the like. Examples of the aromatic solvent include toluene, xylene, tetralin and the like. Examples of the alcohol solvent (excluding the above-mentioned glycol ether solvent) include ethanol, propanol, butanol and the like.

The metal paste may be a dispersant, a surface treatment agent, a friction improver, an infrared absorber, an ultraviolet absorber, a fragrance, an antioxidant, an organic pigment, an inorganic pigment, a defoaming agent, or a silane coupling agent, if necessary. , Titanate-based coupling agent, plasticizer, flame retardant, moisturizing agent, ion scavenger and the like can be contained.

Each of the first electrodes 31 has a strip shape extending in the sub-scanning direction Y, and they are not conducting with each other. Therefore, each first electrode 31 may be individually applied with different potentials when a printer with a built-in thermal printhead is used. An individual pad portion (not shown) is connected to the end portion of each first electrode 31. The individual pad portion is provided apart from the heat generation resistor 40 and is not covered with the insulating layer 35.

The insulating layer 35 is provided so that the first electrode 31 and the second electrode 32 do not come into direct contact with each other. Further, the insulating layer 35 does not completely cover each of the first electrodes 31, and a part of each of the first electrodes 31 has a region not covered by the insulating layer 35, and each of the first electrodes 31 has a region. The electrode 31 is in contact with the heat generation resistor 40 via a region not covered by the insulating layer 35. The insulating layer 35 is made of, for example, amorphous glass. The insulating layer 35 is formed by printing a thick film of glass paste and then firing it.

In the heat generation resistor 40, the portion where the current flows from the individual electrodes and the common electrode generates heat. Specifically, the heat generation resistor 40 to which the heat generation voltage is individually applied according to the print signal transmitted from the outside to the drive IC or the like is selectively generated. The heat generation resistance unit 41 is selectively heated by being individually energized according to the print signal. The heat generated in this way forms print dots. As the heat generation resistor 40, a material having a higher resistivity than the material constituting the wiring can be used, and for example, ruthenium oxide or the like can be used. The heat generation resistor 40 can be formed by screen printing or firing a resistor paste supplied by a dispenser. In the present embodiment, the dimension of the heat generation resistor 40 in the thickness direction Z is, for example, about 1 to 10 μm.

A plurality of second electrodes 32, which are common electrodes, formed of a metal paste are provided on the heat generation resistance portion 41 and the insulating layer 35. The second electrode 32 is obtained by applying a metal paste by a screen printing method or the like to form an electrode pattern. The second electrode 32 may use the same material as that described in the first electrode 31, or a different material, for example, even if each of the first electrode 31 and the second electrode 32 is copper. Often, the first electrode 31 may be copper and the second electrode may be gold.

The second electrode 32, which is a common electrode, is a portion that is electrically opposite to the plurality of first electrodes 31 when a printer incorporating a thermal print head is used. The common electrode has a second electrode 32, which is a comb tooth portion 32A, and a common portion 32B, which connects the comb tooth portion 32A in common. In the present embodiment, the comb tooth portion 32A and the common portion 32B may be collectively referred to as a second electrode 32. The common portion 32B is formed in the main scanning direction X along the upper edge of the substrate 15. In the sub-scanning direction Y, the direction in which the second electrode 32 is located when viewed from the first electrode 31 is defined as the upper side of the sub-scanning direction Y. Each comb tooth portion 32A has a band shape extending in the sub-scanning direction Y. The tip of each comb tooth portion 32A is located in the region between the tips of two adjacent first electrodes 31 and is spaced apart from the two first electrodes 31 along the main scanning direction X. Are opposed to each other.

The tip portion of each comb tooth portion 32A may be opposed to the tip portion of each first electrode 31 at a predetermined interval along the sub-scanning direction Y. In this case, it is preferable that the heat generation resistance portion 41 is formed only in the region where the tip portion of the comb tooth portion 32A and the tip portion of the first electrode 31 face each other. In other words, in the main scanning direction X, it is preferable that the heat generation resistance portion 41 is not arranged except in the region where the tip portion of the comb tooth portion 32A and the tip portion of the first electrode 31 face each other.

In the present embodiment, one end of the first electrode 31 overlaps with one of the two adjacent second electrodes 32 in the main scanning direction X, and the other end of the first electrode 31 is two adjacent ones. It overlaps with the other of the second electrode 32. With such a configuration, the pitch between the electrodes (equal to the pitch between the heat generation resistance portions) can be narrowed, and the printing characteristics on the printing medium can be improved.

Further, in the main scanning direction X, the width of the region overlapping with one of the two second electrodes 32 adjacent to the first electrode 31 is the width of the two second electrodes 32 adjacent to the first electrode 31. It is preferable that the width of the region overlapped with the other is the same, because the heat generated can be evenly distributed. Here, "the same width" includes those in which the difference between the two widths is 5% or less based on the larger of the two widths.

The plurality of second electrodes 32, the heat generating resistor 40, the insulating layer 35, etc. are covered with the protective film 34, and the plurality of second electrodes 32, the heat generating resistor 40, the insulating layer 35, etc. are worn and corroded. , Protect from oxidation, etc. Insulating material can be used for the protective film 34, for example, it is made of amorphous glass. The protective film 34 is formed by printing a thick film of glass paste and then firing it. The dimension of the protective film 34 in the thickness direction Z is, for example, about 3 to 8 μm.

Here, a method of manufacturing the thermal print head 100A of the present embodiment will be described.

As shown in FIGS. 4 to 6, first, a substrate 15 is prepared, a glass paste is applied onto the substrate 15 by screen printing or the like, the applied glass paste is dried, and then heat treatment is performed on the substrate 15. The heat storage layer 33 is formed in the paste. The firing treatment is performed at, for example, 850 to 1200 ° C. for 1 to 5 hours.

Next, as shown in FIGS. 7 to 9, a plurality of first electrodes 31 are formed on the heat storage layer 33. The plurality of first electrodes 31 can be obtained by applying the above-mentioned metal paste by screen printing or the like to form an electrode pattern.

Next, as shown in FIGS. 10 to 12, an insulating layer 35 covering a part of each of the plurality of first electrodes 31 is formed. The insulating layer 35 does not completely cover each of the first electrodes 31, and a part of each of the first electrodes 31 has a region not covered by the insulating layer 35. In the present embodiment, the insulating layer 35 has a strip shape extending in the main scanning direction X, and the central portion of each of the first electrodes 31 is a region in contact with the heat generation resistor 40 described later, so that the insulating layer 35 is formed. Not covered with.

Next, as shown in FIGS. 13 to 15, a heat generation resistor 40 (heat generation resistance portion 41) covering a region not covered by the insulating layer 35 is formed by a thick film forming technique in the plurality of first electrodes 31. do. The heat generation resistor 40 is formed by screen printing or firing a resistor paste supplied by a dispenser. The resistor paste contains, for example, ruthenium oxide.

By forming the insulating layer 35 and the heat generation resistor 40, the plurality of first electrodes 31 are completely covered. Further, the individual pad portion (not shown) connected to the end portion of each first electrode 31 is provided apart from the heat generation resistor 40 and is not covered with the insulating layer 35. In the present embodiment, after the insulating layer 35 is formed, the heat generating resistance 40 that covers the region not covered by the insulating layer 35 is formed, but the heat generation resistance is not limited to this, and the heat generation resistance is formed at the central portion of each of the first electrodes 31. After forming the body 40, the insulating layer 35 may be formed to cover the region not covered by the heat generation resistor 40.

Next, as shown in FIGS. 16 to 18, a plurality of second electrodes 32 are formed on the heat generation resistor 40 and the insulating layer 35. The second electrode 32 is a part of the common electrode, and the common electrode has a second electrode 32 which is a comb tooth portion 32A and a common portion 32B which connects the comb tooth portion 32A in common. The second electrode 32 can be obtained by applying the above-mentioned metal paste by screen printing or the like to form an electrode pattern.

In the present embodiment, one end of the first electrode 31 overlaps with one of the two adjacent second electrodes 32 in the main scanning direction X, and the other end of the first electrode 31 is two adjacent ones. It overlaps with the other of the second electrode 32. With such a configuration, the pitch between the electrodes (equal to the pitch between the heat generation resistance portions) can be narrowed, and the printing characteristics on the printing medium can be improved.

Next, as shown in FIGS. 1 to 3, the protective film 34 is formed. The protective film 34 is made of, for example, amorphous glass. The protective film 34 is formed by printing a thick film of glass paste and then firing it.

By the above steps, the thermal print head of the present embodiment can be manufactured.

According to the present embodiment, one end of the first electrode 31 is superposed on one of two adjacent second electrodes 32, and the other end of the first electrode 31 is adjacent to the second second electrode. By superimposing it on the other of the electrodes 32, the pitch between the electrodes can be narrowed and the printing characteristics on the printing medium can be improved.

(Embodiment 2)
The thermal print head according to this embodiment will be described with reference to the drawings.

FIG. 19 is a partial perspective view showing a thermal print head. FIG. 20 is a partial cross-sectional view taken along the line AA'of FIG. 19 in the main scanning direction X. FIG. 21 is a partial cross-sectional view taken along the line BB'of FIG. 19 in the sub-scanning direction Y. 19 to 21 show a part of a thermal print head (corresponding to one thermal print head), and in the present embodiment, this one thermal print head is a piece-shaped thermal print head 100B. .. The thermal print head 100B includes a heat storage layer 33, a first electrode portion on the heat storage layer 33, a heat generation resistor 40 on the first electrode portion, a second electrode portion on the heat storage resistor 40, and a second electrode portion. It is provided with at least a protective film 34 that covers the electrode portion of 2 and the heat generation resistor 40. Specifically, the thermal print head 100B includes a substrate 15, a heat storage layer 33 on the substrate 15, a plurality of third electrodes 30 included in a first electrode portion on the heat storage layer 33, and a plurality of third electrodes. A heat generating resistor 40 covering each of the electrodes 30 and a plurality of first electrodes 31 and a plurality of second electrodes 32 included in the second electrode portion on the heat generating resistor 40 and the heat storage layer 33. A plurality of first electrodes 31, a plurality of second electrodes 32, and a protective film 34 covering the heat generation resistor 40 are provided. The first electrode 31 and the second electrode 32 are arranged alternately. In the present embodiment, the ordinal numbers "first", "second", and "third" are added to avoid confusion of the components, and the scope of claims and the ordinal numbers may differ.

Further, one of the first electrode 31 and the second electrode 32 is an individual electrode, and the other of the first electrode 31 and the second electrode 32 is a common electrode. In this embodiment, the first electrode The electrode 31 is an individual electrode, and the other of the second electrodes 32 is a common electrode. For example, in the present embodiment, the first electrode 31 is an individual electrode and the other of the second electrodes 32 is a common electrode. , A common electrode. The heat generation resistor 40 includes a plurality of heat generation resistance portions 41 that generate heat due to the current flowing through the individual electrodes and the common electrode. In the plurality of heat generation resistance portions 41, each heat generation resistance portion 41 is independently formed between the first electrode 31 and the second electrode 32. In FIG. 1, a plurality of heat generation resistance portions 41 are omitted. The plurality of heat generation resistance portions 41 are arranged linearly on the heat storage layer 33. Further, in FIG. 19, the protective film 34 is omitted for ease of understanding.

For the substrate 15, the heat generation resistor 40 (heat generation resistance portion 41), and the protective film 34, the description of the first embodiment can be referred to.

A plurality of third electrodes 30 formed from the metal paste are provided on the heat storage layer 33. The third electrode 30 is obtained by applying a metal paste by a screen printing method or the like to form an electrode pattern. Further, the third electrode 30 may be formed by a lithography process. As the third electrode 30, the same material as that of the first electrode 31 described in the first embodiment or a different material can be used.

A current flows from the common electrode to the third electrode 30 via the heat generation resistor 40, and further, a current flows from the third electrode 30 to the individual electrodes via the heat generation resistor 40. By forming such a current path, it is possible to evenly disperse the heat generated, and it is possible to improve the printing characteristics on the printing medium.

A plurality of first electrodes 31 and a plurality of second electrodes 32 are provided on the heat generation resistor 40 and the heat storage layer 33. The description of the first embodiment can be incorporated except for the positions where the plurality of first electrodes 31 and the plurality of second electrodes 32 are provided.

Here, a method of manufacturing the thermal print head 100B of the present embodiment will be described.

As shown in FIGS. 22 to 24, first, a substrate 15 is prepared, a glass paste is applied onto the substrate 15 by screen printing or the like, the applied glass paste is dried, and then heat treatment is performed on the substrate 15. The heat storage layer 33 is formed in the paste. The firing process is carried out at 1250 ° C. for 4.5 hours, for example.

Next, as shown in FIGS. 25 to 27, a plurality of third electrodes 30 are formed on the heat storage layer 33. The plurality of third electrodes 30 can be obtained, for example, by forming an electrode pattern using a lithography process.

Next, as shown in FIGS. 28 to 30, a heat generating resistor 40 (heat generation resistance portion 41) covering each of the plurality of third electrodes 30 is formed by a thick film forming technique. By forming the heat generation resistor 40, the plurality of third electrodes 30 are completely covered. The heat generation resistor 40 is formed by screen printing or firing a resistor paste supplied by a dispenser. The resistor paste contains, for example, ruthenium oxide.

Next, as shown in FIGS. 31 to 33, a plurality of first electrodes 31 and a plurality of second electrodes 32 are formed on the heat generation resistor 40 and the heat storage layer 33. The second electrode 32 is a part of the common electrode, and the common electrode has a second electrode 32 which is a comb tooth portion 32A and a common portion 32B which connects the comb tooth portion 32A in common. Further, the first electrode 31 and the second electrode 32 are arranged alternately. Further, the third electrode 30 is arranged in the region between the first electrode 31 and the second electrode 32. The plurality of first electrodes 31 and the plurality of second electrodes 32 can be obtained by applying the above-mentioned metal paste by screen printing or the like to form an electrode pattern.

In the present embodiment, a current path is formed in which a current flows from the common electrode to the third electrode 30 via the heat generation resistor 40, and further, a current flows from the third electrode 30 to the individual electrodes via the heat generation resistor 40. By doing so, the heat generated can be evenly distributed, and the printing characteristics on the printing medium can be improved.

Next, as shown in FIGS. 19 to 21, the protective film 34 is formed. The protective film 34 is made of, for example, amorphous glass. The protective film is formed by printing a thick film of glass paste and then firing it.

By the above steps, the thermal print head of the present embodiment can be manufactured.

According to the present embodiment, by interposing the third electrode 30 in a part of the current path through which the current flows from the common electrode to the individual electrodes, it becomes possible to evenly disperse the heat generated and the print medium. The printing characteristics on the surface can be improved.

(Other embodiments)
As mentioned above, some embodiments have been described, but the statements and drawings that form part of the disclosure are exemplary and should not be understood as limiting. This disclosure will reveal to those skilled in the art various alternative embodiments, examples and operational techniques. As described above, the present embodiment includes various embodiments not described here.

For example, in the thermal print head 100C which is a modification 1 of the thermal print head 100A of the first embodiment, as shown in FIG. 34, the width of the first electrode 31 is the width of the second electrode 32 in the main scanning direction X. Smaller. With such a configuration, when the first electrode 31 is an individual electrode, the width of the individual electrode is small, so that the current path through which the current flows from the common electrode to the individual electrode can be concentrated. This makes it possible to control the distribution of heat generated and further improve the printing characteristics on the printing medium.

Further, as shown in FIG. 35, the thermal print head 100D, which is the second modification of the thermal print head 100A of the first embodiment, has a configuration in which the first electrode 31 and the second electrode 32 do not overlap each other. good.

Further, as shown in FIG. 36, the thermal print head 100E, which is the third modification of the thermal print head 100A of the first embodiment, has a configuration in which the second electrode 32 completely overlaps with the first electrode 31. You may.

As shown in FIG. 37, the thermal print head 100F, which is a modification 1 of the thermal print head 100B of the second embodiment, has a first electrode 31 adjacent to one end of the third electrode 30 in the main scanning direction X. And one of the second electrodes 32, and the other end of the third electrode 30 overlaps with the other of the adjacent first electrode 31 and the second electrode 32. With such a configuration, the distance between the third electrode 30 and the first electrode 31 and the distance between the third electrode 30 and the second electrode 32 can be shortened, so that the heat generating resistor can be shortened. The current path at 40 is shortened, and the spread of heat generated can be controlled. By this control, the printing characteristics on a printing medium can be further improved.

Further, as shown in FIG. 38, the thermal print head 100G, which is a modification 2 of the thermal print head 100B of the second embodiment, has a configuration in which the third electrode 30 is finely divided as compared with FIG. 37. .. The configuration consists of a third electrode 30 from the common electrode via the heat generation resistor 40, then another third electrode 30 adjacent to the third electrode 30 via the heat generation resistor 40, and further adjacent to the third electrode 30. A current path is formed in which a current flows from the other third electrode 30 to the individual electrodes via the heat generation resistor 40. A current flows from one third electrode 30 to another adjacent third electrode 30 via the heat generation resistor 40, and heat is generated in this path as well, so that the heat generated can be distributed more evenly. Therefore, the printing characteristics on the printing medium can be further improved.

Further, as shown in FIG. 39, in the thermal print head 100H which is a modification 3 of the thermal print head 100B of the second embodiment, the width of the third electrode 30 is the width of the first electrode 31 and the width of the first electrode 31 in the main scanning direction. If the width of the second electrode 32 is larger than the width of the second electrode 32, the distance between both ends of the third electrode 30 becomes large, so that the heat distribution in the vicinity of both ends of the third electrode 30 can be more evenly distributed, and the print medium can be printed. The printing characteristics on the surface can be further improved.

<Thermal printer>
In the thermal print head of the present embodiment (for example, the thermal print head 100A), as shown in FIG. 40, the substrate 15 (heat storage layer 33 on the substrate 15, the first electrode layer, the first electrode layer, etc.) (Not shown), a connection board 5, a heat dissipation member 8, a drive IC 7, a plurality of wires 81, a resin portion 82, and a connector 59. The substrate 15 and the connection substrate 5 are mounted on the heat radiating member 8 so as to be adjacent to each other in the sub-scanning direction Y. A plurality of heat generation resistance portions 41 arranged in the main scanning direction X are formed on the substrate 15. The heat generation resistance unit 41 is driven so as to selectively generate heat by the drive IC 7 mounted on the connection substrate 5. The heat generation resistance unit 41 prints on a printing medium 92 such as thermal paper pressed by the platen roller 91 against the heat generation resistance unit 41 according to a print signal transmitted from the outside via the connector 59.

As the connection board 5, for example, a printed wiring board can be used. The connection board 5 has a structure in which a base material layer and a wiring layer (not shown) are laminated. For the base material layer, for example, a glass epoxy resin or the like can be used. For the wiring layer, for example, metals such as copper, silver, palladium, iridium, platinum, and gold can be used.

The heat radiating member 8 has a function of dissipating heat from the substrate 15. A substrate 15 and a connection substrate 5 are attached to the heat radiating member 8. For the heat radiating member 8, for example, a metal such as aluminum can be used.

As the wire 81, for example, a conductor such as gold can be used. There are a plurality of wires 81, and a part of them is connected to the drive IC 7 and each individual electrode by bonding. Further, a part of the other wires 81 is bonded to the drive IC 7 and the connector 59 via the wiring layer in the connection board 5.

For the resin portion 82, for example, a black resin can be used. As the resin portion 82, for example, an epoxy resin, a silicone resin, or the like can be used. The resin portion 82 covers the drive IC 7 and the plurality of wires 81, and protects the drive IC 7 and the plurality of wires 81. The connector 59 is fixed to the connection board 5. Wiring for supplying electric power to the thermal printhead from the outside of the thermal printhead and controlling the drive IC 7 is connected to the connector 59.

The thermal printer of this embodiment can include the above-mentioned thermal print head. The thermal printer prints on a print medium conveyed along the sub-scanning direction Y. Normally, the print medium is conveyed from the side of the connector 59 toward the side of the heat generation resistance portion 41. Examples of the print medium include a bar code sheet, thermal paper for producing a receipt, and the like.

The thermal printer includes, for example, a thermal print head 100A, a platen roller 91, a main power supply circuit, a measurement circuit, and a control unit. The platen roller 91 faces the thermal print head 100A.

The main power supply circuit supplies electric power to a plurality of heat generation resistance portions 41 in the thermal print head 100A. The measurement circuit measures the resistance value of each of the plurality of heat generation resistance units 41. The measurement circuit measures, for example, the resistance value of each of the plurality of heat generation resistance units 41 when printing is not performed on the print medium. This makes it possible to confirm the life of the heat generation resistance unit 41 and the presence or absence of the failed heat generation resistance unit 41. The control unit controls the drive state of the main power supply circuit and the measurement circuit. The control unit controls the energization state of each of the plurality of heat generation resistance units 41. The measurement circuit may be omitted.

The connector 59 is used to communicate with a device outside the thermal printhead 100A. The thermal print head 100A is electrically connected to the main power supply circuit and the measurement circuit via the connector 59. The thermal print head 100A is electrically connected to the control unit via the connector 59.

The drive IC 7 receives a signal from the control unit via the connector 59. The drive IC 7 controls the energization state of each of the plurality of heat generation resistance units 41 based on the signal received from the control unit. Specifically, the drive IC 7 arbitrarily generates heat in any of the plurality of heat generation resistance portions 41 by selectively energizing a plurality of individual electrodes.

Next, how to use the thermal printer will be described.

At the time of printing on a print medium, the potential v11 is applied to the connector 59 as the potential V1 from the main power supply circuit. In this case, the plurality of heat generation resistance portions 41 are selectively energized to generate heat. By transferring the heat to the print medium, printing on the print medium is performed. As described above, when the potential v11 is applied to the connector 59 as the potential V1 from the main power supply circuit, an energization path to each of the plurality of heat generation resistance portions 41 is secured.

When printing is not performed on the print medium, the resistance value of each heat generation resistance unit 41 is measured. At the time of the measurement, no potential is applied to the connector 59 from the main power supply circuit. At the time of measuring the resistance value of each heat generation resistance unit 41, the potential v12 is applied to the connector 59 as the potential V1 from the measurement circuit. In this case, the plurality of heat generation resistance portions 41 are energized in order (for example, in order from the heat generation resistance portion 41 located at the end of the main scanning direction X). The measurement circuit measures the resistance value of each heat generation resistance unit 41 based on the value of the current flowing through the heat generation resistance unit 41 and the potential v12. As described above, when the potential v11 is applied to the connector 59 as the potential V1 from the main power supply circuit, the energization path to each of the plurality of heat generation resistance portions 41 is substantially cut off. As a result, the resistance value of each heat generation resistance unit 41 can be measured more accurately by the measurement circuit, and the life of the heat generation resistance unit 41 and the presence or absence of the failed heat generation resistance unit 41 can be confirmed.

According to this embodiment, it is possible to obtain a thermal printer that improves the printing characteristics on a printing medium.

5 Connection board 7 Drive IC
8 Heat dissipation member 15 Substrate 30 Third electrode 31 First electrode 32 Second electrode 32A Comb tooth part 32B Common part 33 Heat storage layer 34 Protective film 35 Insulation layer 40 Heat generation resistor 41 Heat generation resistance part 59 Connector 81 Wire 82 Resin Part 91 Platen roller 92 Printing medium 100A, 100B, 100C, 100D, 100E, 100F, 100G, 100H Thermal print head

Claims (15)

With the heat storage layer,
The first electrode portion on the heat storage layer and
The heat-generating resistor on the first electrode portion and
The second electrode portion on the heat generation resistor and
A thermal print head comprising the second electrode portion and a protective film covering the heat generation resistor. The first electrode portion has a plurality of first electrodes and has a plurality of first electrodes.
The second electrode portion has a plurality of second electrodes and has a plurality of second electrodes.
The thermal according to claim 1, wherein one of the plurality of first electrodes is superimposed on one of the plurality of second electrodes and is superimposed on the other one of the plurality of second electrodes. Print head. The thermal printhead according to claim 2, wherein the width of the first electrode is smaller than the width of the second electrode in the main scanning direction. In the main scanning direction, the width of the region where one of the plurality of first electrodes and one of the plurality of second electrodes overlap is the width of the one of the plurality of first electrodes and the plurality of second electrodes. The thermal printhead according to claim 2 or 3, which has the same width as the region on which the other one of the electrodes is superimposed. One of the first electrode and the second electrode is an individual electrode.
The other of the first electrode and the second electrode is a common electrode.
Any of claims 2 to 4, wherein each of the plurality of first electrodes or the plurality of second electrodes, which are the common electrodes, is a comb tooth portion and is connected to the common portion of the common electrode. The thermal print head according to item 1. Further, it has an insulating layer located between a part of the first electrode portion and a part of the second electrode portion.
The thermal print according to any one of claims 2 to 5, wherein at least one of the insulating layer and the heat generation resistor is provided between the first electrode portion and the second electrode portion. head. The first electrode portion has a plurality of first electrodes and has a plurality of first electrodes.
The second electrode portion has a plurality of second electrodes and a plurality of third electrodes different from the second electrode.
The thermal print head according to claim 1, wherein the second electrode and the third electrode are arranged alternately. The thermal print head according to claim 7, wherein one of the plurality of first electrodes is superimposed on one of the plurality of second electrodes and is superimposed on one of the plurality of third electrodes. .. The thermal printhead according to claim 7 or 8, wherein the width of the first electrode is larger than the width of the second electrode and the width of the third electrode in the main scanning direction. One of the second electrode and the third electrode is an individual electrode.
The other of the second electrode and the third electrode is a common electrode.
Any of claims 7 to 9, wherein each of the plurality of second electrodes or the plurality of third electrodes, which are the common electrodes, is a comb tooth portion and is connected to the common portion of the common electrode. The thermal print head according to item 1. A thermal printer comprising the thermal print head according to any one of claims 1 to 10. Form a heat storage layer,
A plurality of first electrodes are formed on the heat storage layer, and a plurality of first electrodes are formed.
An insulating layer covering a part of each of the plurality of first electrodes is formed.
In the plurality of first electrodes, a heat generation resistor covering a region not covered with the insulating layer is formed.
A plurality of second electrodes are formed on the heat generation resistor and the insulating layer, and a plurality of second electrodes are formed.
A method for manufacturing a thermal print head, which forms a protective film covering the plurality of second electrodes, the heat generation resistor, and the insulating layer. One of the first electrode and the second electrode is an individual electrode.
The other of the first electrode and the second electrode is a common electrode.
The thermal print according to claim 12, wherein each of the plurality of first electrodes or the plurality of second electrodes, which are the common electrodes, is a comb tooth portion and is connected to the common portion of the common electrode. How to make the head. Form a heat storage layer,
A plurality of first electrodes are formed on the heat storage layer, and a plurality of first electrodes are formed.
A heat-generating resistor that covers the plurality of first electrodes is formed.
A plurality of second electrodes and a plurality of third electrodes different from the second electrodes are formed on the heat generation resistor and the heat storage layer.
A protective film covering the plurality of second electrodes, the plurality of third electrodes, and the heat generation resistor is formed.
A method for manufacturing a thermal print head, in which the second electrode and the third electrode are arranged alternately. One of the second electrode and the third electrode is an individual electrode.
The other of the second electrode and the third electrode is a common electrode.
The thermal print according to claim 14, wherein each of the plurality of second electrodes or the plurality of third electrodes, which are the common electrodes, is a comb tooth portion and is connected to the common portion of the common electrode. How to make the head.

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