JP2022111568A - Thermal print head, manufacturing method of the same, and thermal printer - Google Patents

Abstract

To provide a manufacturing method of a thermal print head which can reduce manufacturing cost, provide the thermal print head which can be manufactured by the manufacturing method of the thermal print head, and provide a thermal printer provided with the thermal print head.SOLUTION: In a manufacturing method of a thermal print head 100, a heat accumulation layer 33 is formed on an insulator; a plurality of groove parts 30 are formed on the heat accumulation layer 33; electrodes embedded in the respective groove parts 30 are formed; a plurality of electrodes embedded in the groove parts 30 are electrically connected; a heat element 40 is formed on the heat accumulation layer 33; and the plurality of electrodes embedded in the groove parts 30 have a plurality of individual electrodes 31, and a plurality of common electrodes 32 different from the individual electrodes 31. The individual electrodes 31 and common electrode 32 are alternately arranged.SELECTED DRAWING: Figure 1

Description

The present embodiment relates to a thermal printhead, its manufacturing method, and a thermal printer.

A thermal print head, for example, has a large number of heat generating portions arranged in the main scanning direction on a head substrate. Each heat generating portion is formed by laminating a common electrode and an individual electrode on a resistor layer formed on a head substrate with a glaze layer interposed therebetween, with their ends facing each other, with a portion of the resistor layer exposed. It is 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 print medium (a bar code sheet, thermal paper for creating a receipt, etc.), printing is performed on the print medium.

The common electrode, the individual electrodes, and the like are formed into electrode patterns by patterning using a photolithography process.

JP-A-2000-141729

However, processing electrode patterns using photolithography requires expensive masks and processing equipment. One aspect of the present embodiment provides a method of manufacturing a thermal printhead that can reduce manufacturing costs. Another aspect of the present embodiment provides a thermal printhead that can be manufactured by the method for manufacturing a thermal printhead. Another aspect of the present embodiment provides a thermal printer including the thermal print head.

This embodiment can reduce the manufacturing cost of the thermal printhead by not using a photolithography process that requires an expensive mask and processing equipment to form the electrode pattern. One aspect of this embodiment is as follows.

In one aspect of the present embodiment, a heat storage layer is formed on an insulator, a plurality of grooves are formed in the heat storage layer, an electrode is formed in each of the grooves, and an electrode is formed in each of the grooves on the heat storage layer. forming a heating resistor electrically connected to a plurality of embedded electrodes, wherein the plurality of electrodes embedded in the groove has a plurality of individual electrodes and a plurality of common electrodes different from the individual electrodes; In the method of manufacturing a thermal printhead, the individual electrodes and the common electrodes are alternately arranged.

Another aspect of the present embodiment includes an insulator, a heat storage layer on the insulator and having a plurality of grooves, a plurality of electrodes embedded in each of the grooves, and the heat storage layer. a heating resistor on the layer and electrically connected to the plurality of electrodes, the plurality of electrodes having a plurality of individual electrodes and a plurality of common electrodes different from the individual electrodes. , the individual electrodes and the common electrodes are arranged alternately in a thermal printhead.

Another aspect of the present embodiment is a thermal printer including the thermal print head.

According to this embodiment, it is possible to provide a method of manufacturing a thermal print head that can reduce manufacturing costs. Moreover, it is possible to provide a thermal printhead that can be manufactured by the method for manufacturing a thermal printhead. Furthermore, it is possible to provide a thermal printer equipped with the thermal print head.

FIG. 1 is a partial perspective view illustrating a thermal print head according to this embodiment. 2 is a partial cross-sectional view along line AA in FIG. 1 in the main scanning direction X. FIG. 3 is a partial cross-sectional view along the line BB in FIG. 1 in the sub-scanning direction Y. FIG. 4 is an enlarged cross-sectional view of the periphery of the groove in FIG. 2. FIG. FIG. 5 is a partial perspective view for explaining the method of manufacturing the thermal print head according to this embodiment (No. 1). 6 is a partial cross-sectional view along line AA in FIG. 5 in the main scanning direction X. FIG. 7 is a partial cross-sectional view along the line BB in FIG. 5 in the sub-scanning direction Y. FIG. FIG. 8 is a partial perspective view explaining the method of manufacturing the thermal print head according to this embodiment (No. 2). 9 is a partial cross-sectional view along line AA in FIG. 8 in the main scanning direction X. FIG. 10 is a partial cross-sectional view along the line BB in FIG. 8 in the sub-scanning direction Y. FIG. FIG. 11 is a partial perspective view for explaining the method of manufacturing the thermal print head according to this embodiment (No. 3). 12 is a partial cross-sectional view along line AA in FIG. 11 in the main scanning direction X. FIG. 13 is a partial cross-sectional view along line BB in FIG. 11 in the sub-scanning direction Y. FIG. FIG. 14 is a partial perspective view for explaining the method of manufacturing the thermal print head according to this embodiment (No. 4). 15 is a partial cross-sectional view along line AA in FIG. 14 in the main scanning direction X. FIG. 16 is a partial cross-sectional view along line BB in FIG. 14 in the sub-scanning direction Y. FIG. FIG. 17 is a partial perspective view explaining the method of manufacturing the thermal print head according to this embodiment (No. 5). 18 is a partial cross-sectional view along line AA in FIG. 17 in the main scanning direction X. FIG. 19 is a partial cross-sectional view along line BB in FIG. 17 in the sub-scanning direction Y. FIG. FIG. 20 is a partial perspective view explaining the method of manufacturing the thermal print head according to this embodiment (No. 6). 21 is a partial cross-sectional view along line AA in FIG. 20 in the main scanning direction X. FIG. 22 is a partial cross-sectional view along line BB in FIG. 20 in the sub-scanning direction Y. FIG. FIG. 23 is a partial perspective view explaining the method of manufacturing the thermal print head according to this embodiment (No. 7). 24 is a partial cross-sectional view along line AA in FIG. 23 in the main scanning direction X. FIG. 25 is a partial cross-sectional view along line BB in FIG. 23 in the sub-scanning direction Y. FIG. FIG. 26 is a cross-sectional view illustrating another thermal printhead according to this embodiment. FIG. 27 is a cross-sectional view illustrating a thermal print head according to this embodiment.

Next, this embodiment will be described with reference to the drawings. In the description of the drawings described below, the same or similar parts are denoted 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 planar dimensions, etc., differs from the actual one. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. In addition, it goes without saying that there are portions with different dimensional relationships and ratios between the drawings.

Further, the embodiments shown below are examples of apparatuses and methods for embodying technical ideas, and do not specify the material, shape, structure, arrangement, etc. of each component. Various modifications can be made to this embodiment within the scope of the claims.

One specific aspect of this embodiment is as follows.

<1> A heat storage layer is formed on an insulator, a plurality of grooves are formed in the heat storage layer, electrodes are formed in each of the grooves, and a plurality of electrodes embedded in the grooves are formed on the heat storage layer. The plurality of electrodes embedded in the groove, forming a heating resistor electrically connected to the electrodes of the heating resistor, has a plurality of individual electrodes and a plurality of common electrodes different from the individual electrodes, and the individual electrodes and the common A method of manufacturing a thermal printhead, wherein the electrodes are staggered.

<2> The method of manufacturing a thermal print head according to <1>, wherein the groove is formed by etching.

<3> The method of manufacturing a thermal print head according to <2>, wherein hydrofluoric acid is used for the etching.

<4> The method of manufacturing a thermal print head according to any one of <1> to <3>, wherein the individual electrodes and the common electrodes are alternately arranged along the main scanning direction.

<5> Manufacture of the thermal printhead according to any one of <1> to <4>, wherein, in the plurality of grooves, surfaces formed between the side surfaces of the grooves and the bottom surfaces of the grooves have curved surfaces. Method.

<6> The method of manufacturing a thermal print head according to any one of <1> to <5>, wherein the plurality of electrodes have concave curved upper surfaces.

<7> The method of manufacturing a thermal print head according to any one of <1> to <6>, wherein the plurality of electrodes embedded in the grooves are formed by etching.

<8> The thermal print according to any one of <1> to <7>, further comprising, on the heat storage layer, forming pad electrodes electrically connected to the plurality of electrodes embedded in the grooves. How the head is made.

<9> The method of manufacturing a thermal print head according to any one of <1> to <8>, further comprising forming a protective film covering the heating resistor and the plurality of electrodes.

<10> an insulator; a heat storage layer on the insulator and having a plurality of grooves; a plurality of electrodes embedded in each of the grooves; and a heating resistor electrically connected to the electrodes of, the plurality of electrodes have a plurality of individual electrodes and a plurality of common electrodes different from the individual electrodes, and the individual electrodes and the common electrode are , alternating thermal printheads.

<11> The thermal print head according to <10>, wherein the individual electrodes and the common electrodes are alternately arranged along the main scanning direction.

<12> The thermal print head according to <10> or <11>, wherein, in the plurality of grooves, surfaces formed between the side surfaces of the grooves and the bottom surfaces of the grooves have curved surfaces.

<13> The thermal printhead according to any one of <10> to <12>, wherein the plurality of electrodes have concave curved upper surfaces.

<14> The thermal printhead according to any one of <10> to <13>, further comprising a pad electrode on the heat storage layer and electrically connected to a plurality of electrodes embedded in the groove. .

<15> The thermal printhead according to any one of <10> to <14>, further comprising a protective film covering the heating resistor and the plurality of electrodes.

<16> The thermal printhead according to any one of <10> to <15>, wherein the insulator is a substrate.

<17> The thermal printhead according to <16>, wherein the substrate is made of ceramic.

<18> A thermal printer comprising the thermal print head according to any one of <10> to <17>.

<Thermal print head>
A 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 printhead. 2 is a partial cross-sectional view along line AA in FIG. 1 in the main scanning direction X. FIG. 3 is a partial cross-sectional view along the line BB in FIG. 1 in the sub-scanning direction Y. FIG. FIG. 4 is an enlarged cross-sectional view around a groove portion 30 described later in FIG. 1 to 3 show a portion of a thermal print head (corresponding to one thermal print head), and in this embodiment, this one thermal print head is assumed to be an individual thermal print head 100. . The thermal print head 100 includes a substrate 15 that is an insulator, a heat storage layer 33 that is on the substrate 15 and has a plurality of grooves 30, and a plurality of electrodes (individual electrodes 31 or a common electrode 32), a pad electrode 35 electrically connected to a plurality of electrodes embedded in the grooves 30 on the heat storage layer 33, and an individual electrode 31 and a common electrode on the heat storage layer 33; and a protective film 34 covering the individual electrodes 31 , the common electrode 32 , the pad electrodes 35 , and the heating resistors 40 . The individual electrodes 31 and the common electrode 32 are alternately arranged, and the heating resistor 40 includes a plurality of heating resistor portions 41 that generate heat by current flowing through the individual electrodes 31 and the common electrode 32 . The plurality of heat generating resistors 41 are formed independently between the individual electrodes 31 and the common electrode 32 . FIG. 1 omits the plurality of heating resistors 41 . The plurality of heat generating resistors 41 are linearly arranged on the heat storage layer 33 . Also, FIG. 1 omits the protective film 34 for easy understanding. The thermal print head 100 also includes pad electrodes (not shown) electrically connected to the individual electrodes 31 in the same manner as the common electrode 32 .

In this embodiment, the main scanning direction X is the direction in which the plurality of heating resistors 41 extend linearly, and the sub-scanning direction Y is the direction perpendicular to the main scanning direction X and parallel to the upper surface of the substrate 15 . , the direction corresponding to the thickness of the substrate 15 is defined as a thickness direction Z. As shown in FIG. In other words, the thickness direction Z is a direction perpendicular to the main scanning direction X and the sub-scanning direction Y, respectively.

The substrate 15 is an insulator and is made of ceramic, for example. As the ceramic, for example, alumina or the like can be used. From the viewpoint of heat dissipation, it is preferable to use alumina, which has relatively high thermal conductivity, for the substrate 15 .

A heat storage layer 33 (also referred to as a glaze layer) having a function of storing heat is laminated on the substrate 15 . The heat storage layer 33 accumulates heat generated from the heating resistor section 41, which will be described later. An insulating material can be used for the heat storage layer 33, and for example, silicon oxide and silicon nitride, which are 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, 5 to 100 μm, preferably 10 to 30 μm.

A plurality of grooves 30 are formed in the heat storage layer 33 . The dimension (depth) of the groove portion 30 in the thickness direction Z is smaller than the thickness of the heat storage layer 33 . That is, the upper surface of the substrate 15 under the heat storage layer 33 is not exposed in the groove 30 .

Further, the groove portion 30 has a side surface 30A and a bottom surface 30B, as shown in FIG. A surface formed between the side surface 30A and the bottom surface 30B may have a curved surface 30C. It is preferable that the groove portion 30 has a curved surface 30C because the individual electrode 31, the common electrode 32, and the like can be formed with good coverage. Similarly to the groove 30 in the cross section along the line AA shown in FIG. 4, the groove 30 in the cross section along the line BB also has a side surface 30A and a bottom surface 30B. may have a curved surface 30C.

An individual electrode 31 or a common electrode 32 made of metal paste is embedded in each of the grooves 30 . The individual electrodes 31 and the common electrode 32 are obtained by applying a metal paste by a screen printing method or the like, then baking and etching to form an electrode pattern.

In this embodiment, the manufacturing cost of the thermal printhead can be reduced by not using a photolithography process that requires expensive masks and processing equipment for forming the electrode pattern.

In addition, as shown in FIG. 4, the individual electrode 31 may have a concave curved surface 31A. Similarly, the common electrode 32 may have a concave curved surface 32A. By having the curved surface 31A and the curved surface 32A, the adhesion with the heating resistor 40 formed on the curved surface 31A and the curved surface 32A is improved, and the distribution of the heat generated by the energization can be evenly distributed. Printing characteristics on a medium can be improved.

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 preferred from the viewpoint of metal properties and ionization tendency, and silver is more preferred from the viewpoint of metal properties, ionization tendency, and cost reduction. In addition, the solvent contained in the metal paste has a function of uniformly dispersing the metal particles, and examples thereof include ester solvents, ketone solvents, glycol ether solvents, aliphatic solvents, alicyclic solvents, and aromatic solvents. Examples include, but are not limited to, one or a mixture of two or more of solvent, alcohol, water, and the like.

Examples of ester solvents include ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, amyl acetate, ethyl lactate and dimethyl carbonate. Ketone solvents include, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone benzene, diisobutyl ketone, diacetone alcohol, isophorone, cyclohexanone and the like. Glycol ether solvents include, for example, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, acetic acid esters of these monoethers, 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, acetic acid esters of these monoethers, and the like.

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

The metal paste may contain dispersants, surface treatment agents, anti-friction agents, infrared absorbers, ultraviolet absorbers, fragrances, antioxidants, organic pigments, inorganic pigments, antifoaming agents, silane coupling agents, if necessary. , a titanate-based coupling agent, a plasticizer, a flame retardant, a humectant, an ion scavenger, and the like.

Each individual electrode 31 has a strip shape extending generally in the sub-scanning direction Y, and they are not electrically connected to each other. Therefore, each individual electrode 31 can be individually given different potentials when a printer incorporating a thermal print head is used. An end of each individual electrode 31 is electrically connected to a pad electrode (not shown).

Each common electrode 32 is a portion electrically opposite in polarity to the plurality of individual electrodes 31 when a printer incorporating a thermal print head is used. In the sub-scanning direction Y, the direction in which the common electrode 32 is located when viewed from the individual electrodes 31 is defined as the upper side of the sub-scanning direction Y. FIG. The common electrode 32 has a strip shape extending in the sub-scanning direction Y. As shown in FIG. An end portion of each common electrode 32 is electrically connected to a pad electrode 35 . The end of the common electrode 32 is located in a region between the ends of two adjacent individual electrodes 31 and is opposed to the two individual electrodes 31 along the main scanning direction X with a predetermined gap. ing.

The end of each common electrode 32 may be opposed to the end of each individual electrode 31 along the sub-scanning direction Y with a predetermined gap therebetween. In this case, it is preferable that the heating resistor portion 41 is formed only in the region where the end portion of the common electrode 32 and the end portion of the individual electrode 31 face each other. In other words, in the main scanning direction X, it is preferable that the heating resistor section 41 is not arranged except for the region where the end portions of the common electrode 32 and the end portions of the individual electrodes 31 face each other.

The heating resistor 40 is electrically connected to the individual electrode 31 and the common electrode 32, and heat is generated in the portion to which the current from the individual electrode 31 and the common electrode 32 flows. Specifically, the heating resistors 40 to which a heating voltage is individually applied according to a print signal sent from the outside to the driving IC or the like are selectively caused to generate heat. The heating resistors 41 are selectively heated by being individually energized according to the print signal. Print dots are formed by such heat generation. The heating resistor 40 is made of a material having a higher resistivity than the material of the individual electrodes 31 and the common electrode 32, such as ruthenium oxide. The heating resistor 40 can be formed by screen printing or firing a resistor paste supplied by a dispenser. In this embodiment, the dimension in the thickness direction Z of the heating resistor 40 is, for example, about 1 to 10 μm.

The heat storage layer 33, the individual electrode 31, the common electrode 32, the pad electrode 35, the heating resistor 40, and the like are covered with a protective film 34, and the heat storage layer 33, the individual electrode 31, the common electrode 32, the pad electrode 35, and the It protects the heating resistor 40 and the like from wear, corrosion, oxidation and the like. The protective film 34 can be made of an insulating material, such as amorphous glass. The protective film 34 is formed by printing a thick film of glass paste and then baking it. The dimension of the protective film 34 in the thickness direction Z is, for example, about 3 to 8 μm.

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

As shown in FIGS. 5 to 7, first, the substrate 15 is prepared, and the heat storage layer 33 is formed on the substrate 15. As shown in FIGS. The heat storage layer 33 can be formed by, for example, applying a glass paste by screen printing or the like, drying the applied glass paste, and then performing a firing treatment. The baking treatment is performed, for example, at 800 to 1200° C. for 10 minutes to 1 hour. The dimension in the thickness direction Z of the heat storage layer 33 is, for example, 25 μm.

Next, as shown in FIGS. 8 to 10, a resist 36 is formed.

Next, as shown in FIGS. 11 to 13, a plurality of grooves 30 are formed by partially removing the heat storage layer 33 using the resist 36 as a mask. The groove portion 30 can be formed by, for example, etching, and specific examples include isotropic etching using hydrofluoric acid, reactive ion etching (RIE), and the like. And from the viewpoint of manufacturing cost reduction, it is preferable to form the groove 30 by isotropic etching using hydrofluoric acid.

The depth of the groove 30 becomes the thickness of the individual electrode 31 and the common electrode 32, which will be described later, and the thickness of the individual electrode 31 and the common electrode 32 depends on their resistance values. Therefore, the resistance values of the individual electrodes 31 and the common electrode 32 can be adjusted by appropriately adjusting the depth of the grooves 30 . The depth of the grooves 30 in which the individual electrodes 31 to be described later are embedded may be the same as or different from the depth of the grooves 30 in which the common electrodes 32 to be described later are embedded. If the depth of the groove 30 in which the electrode 31 is embedded and the depth of the groove 30 in which the common electrode 32 is embedded are the same, the groove 30 in which the individual electrode 31 is embedded and the groove 30 in which the common electrode 32 is embedded are formed in the same process. It is preferable because it can The depth of the groove portion 30 is smaller than the thickness of the heat storage layer 33 , and the upper surface of the substrate 15 under the heat storage layer 33 is not exposed in the groove portion 30 . The depth of the groove portion 30 is, for example, 5 μm.

Next, as shown in FIGS. 14 to 16, individual electrodes 31 or common electrodes 32 are formed in each of the grooves 30. Next, as shown in FIGS. The individual electrodes 31 and the common electrode 32 are formed by applying the above-described metal paste by screen printing or the like, then firing the paste, and partially etching the fired metal paste on the heat storage layer 33. can be obtained by etching the metal paste on the heat storage layer 33 in and forming an electrode pattern.

By forming the individual electrodes 31 and the common electrode 32 so as to be embedded in the plurality of grooves 30 provided in the heat storage layer 33 in this manner, an expensive mask and The manufacturing cost of the thermal print head can be reduced without using a photolithography process that requires a processing apparatus.

Next, as shown in FIGS. 17 to 19, a pad electrode (not shown) electrically connected to the individual electrode 31 embedded in the groove 30 and a common electrode 32 embedded in the groove 30 are formed. A pad electrode 35 electrically connected to is formed. For the pad electrode 35 and the like, for example, the same material and formation method as those of the individual electrode 31 and the common electrode 32 can be used.

Next, as shown in FIGS. 20 to 22, the heating resistors 40 (heating resistor portions 41) are formed on the plurality of individual electrodes 31 and the common electrode 32 by a thick film forming technique. The heating resistor 40 is electrically connected to the multiple individual electrodes 31 and the common electrode 32 . The heating 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. 23 to 25, a protective film 34 is formed. The protective film 34 is made of amorphous glass, for example. The protective film 34 is formed by printing a thick film of glass paste and then baking it.

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

According to this embodiment, by forming the individual electrodes 31 and the common electrode 32 so as to be embedded in the plurality of grooves 30 provided in the heat storage layer 33, it is expensive to form the electrode patterns of the individual electrodes 31 and the common electrode 32. It does not use photolithography processes that require expensive masks and processing equipment. Therefore, the manufacturing cost of the thermal printhead can be reduced.

(Other embodiments)
As noted above, although one embodiment has been described, the discussion and drawings forming part of the disclosure are to be understood as illustrative and not limiting. Various alternative embodiments, implementations and operational techniques will become apparent to those skilled in the art from this disclosure. Thus, this embodiment includes various embodiments and the like that are not described here.

For example, in a thermal print head 100A, which is a first modification of the thermal print head 100 of the present embodiment, as shown in FIG. The resistance value of the individual electrode 31 may be designed to be different from the resistance value of the common electrode 32 by adjusting to be different from the depth.

<Thermal printer>
Further, as shown in FIG. 27, the thermal print head (for example, thermal print head 100) of the present embodiment includes a substrate 15 (the heat storage layer 33 and the like on the substrate 15 are not shown), a connection substrate 5, a heat dissipation member 8, It includes 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 adjacent to each other in the sub-scanning direction Y on the heat dissipation member 8 . A plurality of heating resistors 41 arranged in the main scanning direction X are formed on the substrate 15 . The heat generating resistor portion 41 is driven to selectively generate heat by the driving IC 7 mounted on the connection substrate 5 . The heating resistor section 41 prints on a print medium 92 such as thermal paper that is pressed against the heating resistor section 41 by the platen roller 91 according to a print signal transmitted from the outside through the connector 59 .

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

The heat dissipation 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 dissipation member 8 . Metal such as aluminum can be used for the heat dissipation member 8, for example.

A conductor such as gold can be used for the wire 81, for example. There are a plurality of wires 81, some of which are bonded to electrically connect the driving IC 7 and each individual electrode. Some of the other wires 81 are bonded to connect the drive IC 7 and the connector 59 through the wiring layer of the connection board 5 .

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

The thermal printer of this embodiment can comprise the thermal print head described above. A thermal printer prints on a print medium conveyed along the sub-scanning direction Y. As shown in FIG. Normally, the print medium is conveyed from the connector 59 side toward the heating resistor section 41 side. Print media include, for example, thermal paper for creating barcode sheets and receipts.

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

The main power supply circuit supplies power to the plurality of heating resistors 41 in the thermal print head 100 . The measuring circuit measures the resistance value of each of the plurality of heating resistors 41 . The measurement circuit measures the resistance value of each of the plurality of heating resistors 41, for example, when printing on a print medium is not performed. As a result, the life of the heating resistor 41 and the presence or absence of a failed heating resistor 41 can be checked. The control unit controls driving states of the main power supply circuit and the measurement circuit. The controller controls the energized state of each of the plurality of heating resistors 41 . The measuring circuit may be omitted.

Connector 59 is used to communicate with devices outside thermal printhead 100 . Through connector 59, thermal print head 100 is electrically connected to the main power supply circuit and the measurement circuit. The thermal printhead 100 is electrically connected to the controller via the connector 59 .

The drive IC 7 receives signals from the control section via the connector 59 . The driving IC 7 controls the energization state of each of the plurality of heating resistors 41 based on the signal received from the control section. Specifically, the drive IC 7 selectively energizes a plurality of individual electrodes to arbitrarily generate heat in any one of the plurality of heating resistor portions 41 .

Further, the thermal print head of the present embodiment is not limited to the configuration described above. , or a configuration in which the heat radiating member 8 is not provided.

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

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

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

According to this embodiment, it is possible to obtain a thermal printer capable of reducing manufacturing costs.

5 connection board 7 drive IC
8 Heat dissipation member 15 Substrate 30 Groove 30A Side surface 30B Bottom surface 30C, 31A, 32A Curved surface 31 Individual electrode 32 Common electrode 33 Heat storage layer 34 Protective film 35 Pad electrode 36 Resist 40 Heating resistor 41 Heating resistor 59 Connector 81 Wire 82 Resin portion 91 Platen roller 92 Print medium 100, 100A Thermal print head

Claims (18)

forming a heat storage layer on the insulator,
forming a plurality of grooves in the heat storage layer,
forming an electrode embedded in each of the grooves;
A heating resistor electrically connected to the plurality of electrodes embedded in the groove is formed on the heat storage layer, and the plurality of electrodes embedded in the groove is connected to the plurality of individual electrodes and the individual electrodes. having a plurality of different common electrodes,
A method of manufacturing a thermal printhead, wherein the individual electrodes and the common electrodes are alternately arranged. 2. The method of manufacturing a thermal printhead according to claim 1, wherein said groove is formed by etching. 3. The method of manufacturing a thermal printhead according to claim 2, wherein the etching uses hydrofluoric acid. 4. The method of manufacturing a thermal printhead according to claim 1, wherein the individual electrodes and the common electrodes are alternately arranged along the main scanning direction. 5. The method of manufacturing a thermal print head according to claim 1, wherein, in said plurality of grooves, surfaces formed between side surfaces of said grooves and bottom surfaces of said grooves have curved surfaces. 6. The method of manufacturing a thermal printhead according to claim 1, wherein the plurality of electrodes have concave curved upper surfaces. 7. The method of manufacturing a thermal printhead according to claim 1, wherein the plurality of electrodes embedded in said grooves are formed by etching. 8. The method of manufacturing a thermal printhead according to claim 1, further comprising forming, on said heat storage layer, pad electrodes electrically connected to a plurality of electrodes embedded in said grooves. 9. The method of manufacturing a thermal printhead according to claim 1, further comprising forming a protective film covering said heating resistor and said plurality of electrodes. an insulator;
a heat storage layer on the insulator and having a plurality of grooves;
a plurality of electrodes embedded in each of the grooves;
a heating resistor on the heat storage layer and electrically connected to the plurality of electrodes;
The plurality of electrodes has a plurality of individual electrodes and a plurality of common electrodes different from the individual electrodes,
A thermal printhead, wherein the individual electrodes and the common electrodes are alternately arranged. 11. A thermal printhead according to claim 10, wherein said individual electrodes and said common electrodes are alternately arranged along the main scanning direction. 12. The thermal printhead according to claim 10, wherein, in the plurality of grooves, surfaces formed between side surfaces of the grooves and bottom surfaces of the grooves have curved surfaces. The thermal printhead according to any one of claims 10 to 12, wherein the plurality of electrodes have concave curved upper surfaces. 14. The thermal printhead according to any one of claims 10 to 13, further comprising a pad electrode electrically connected to a plurality of electrodes embedded in said groove on said heat storage layer. 15. The thermal printhead according to claim 10, further comprising a protective film covering said heating resistor and said plurality of electrodes. A thermal printhead according to any one of claims 10 to 15, wherein said insulator is a substrate. 17. The thermal printhead of claim 16, wherein said substrate is made of ceramic. A thermal printer comprising the thermal print head according to any one of claims 10-17.

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