JP2023115544A - Thermal print head, thermal printer and manufacturing method of thermal print head - Google Patents

Abstract

To provide a thermal print head which secures the excellent printing efficiency in the time of printing, a thermal printer which includes the thermal print head, and a manufacturing method of the thermal print head which secures the excellent printing efficiency in the time of printing.SOLUTION: A thermal print head 100 comprises: a heat accumulation layer 33; a heating resistor 40 which is arranged on the heat accumulation layer 33; a common electrode 32 which is arranged on the heat accumulation layer 33 and has a comb tooth part 32A; and an individual electrode 31 which is arranged on the heat accumulation layer 33, is apart from the comb tooth part 32A of the common electrode 32 and is opposed to the comb tooth part 32A. In the thickness direction Z of the heat accumulation layer 33, the individual electrode 31 and the comb tooth part 32A each include a first film thickness part, and a second film thickness part whose film thickness is smaller than the first film thickness part. The heating resistor 40 is in contact with the second film thickness part of the individual electrode 31 and the second film thickness part of the comb tooth part 32A.SELECTED DRAWING: Figure 1A

Description

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

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 glaze layer (also referred to as a heat storage layer), a common electrode, individual electrodes, and a resistor layer on the head substrate. 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 (such as a barcode sheet or thermal paper for creating a receipt), printing is performed on the print medium.

The common electrode, the individual electrodes, and the like are formed into electrode patterns by screen-printing a paste using a metal such as gold or silver (further, a lithography process may be performed). Wirings for supplying voltage from the outside to the common electrode and the individual electrodes are in contact with the common electrode and the individual electrodes, respectively. The wiring is formed by a lithography process using metals such as gold and silver. Gold is expensive, and from the viewpoint of reducing the cost of products, a technique using silver as a relatively inexpensive metal with good electrical conductivity has been proposed.

JP 2012-121283 A

When silver is used as the material for the common electrode, individual electrodes, and wiring, gold is used as the material to reduce the effects of disconnection of the common electrode, individual electrodes, and wiring due to aggregation of silver and diffusion of silver into the protective film. The thickness of the common electrode, the individual electrodes, and the wiring is made thicker than before. However, if the common electrode and the individual electrodes are formed thicker in the vicinity of the heat generating portion, heat conduction (thermal diffusion) from the heat generating portion to the common electrode and the individual electrodes increases. There is a problem that the energy is increased and the printing efficiency (energy efficiency) is lowered when printing on thermal paper or the like.

An object of one aspect of the present embodiment is to provide a thermal print head that ensures good printing efficiency during printing. Another object of the present embodiment is to provide a thermal printer including the thermal print head. Another object of the present embodiment is to provide a method of manufacturing a thermal print head that ensures good printing efficiency during printing.

One aspect of the present embodiment includes a heat storage layer, a heat generating resistor disposed on the heat storage layer, a common electrode disposed on the heat storage layer and having a comb tooth portion, and and an individual electrode that is arranged so as to be separated from the comb tooth portion of the common electrode and face the comb tooth portion, wherein the individual electrode and the comb tooth portion are arranged in the thickness direction of the heat storage layer. , a first film thickness portion and a second film thickness portion having a smaller film thickness than the first film thickness portion, and the heating resistor has the second film thickness of the individual electrode. and the second film thickness portion of the comb tooth portion.

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

In another aspect of the present embodiment, a heat storage layer is formed, and a common electrode having a comb tooth portion on the heat storage layer is separated from the comb tooth portion and faces the comb tooth portion. and an individual electrode having a first film thickness portion and a second film thickness portion, respectively, a heating resistor is formed on the comb tooth portion and the individual electrode, and the heat storage layer In the thickness direction, the film thickness of the second film thickness portion is smaller than the film thickness of the first film thickness portion, and the heat generating resistor includes the second film thickness portion of the individual electrode and the comb. In the method of manufacturing a thermal printhead, the tooth portion is in contact with the second film thickness portion.

In another aspect of the present embodiment, a heat storage layer is formed, a heat generating resistor is formed on the heat storage layer, and a common electrode having a comb tooth portion is formed on the heat storage layer and on the heat generating resistor. and an individual electrode separated from the comb tooth portion and facing the comb tooth portion so as to have a first film thickness portion and a second film thickness portion, respectively; In the thickness direction, the film thickness of the second film thickness portion is smaller than the film thickness of the first film thickness portion, and the heat generating resistor includes the second film thickness portion of the individual electrode and the comb. In the method of manufacturing a thermal printhead, the tooth portion is in contact with the second film thickness portion.

According to this embodiment, it is possible to provide a thermal print head that ensures good printing efficiency during printing. Also, a thermal printer with a thermal print head can be provided. Also, it is possible to provide a method for manufacturing a thermal print head that ensures good printing efficiency during printing.

FIG. 1A is a partial perspective view illustrating a thermal print head according to this embodiment. FIG. 1B is a partial cross-sectional view taken along line IB--IB of FIG. 1A. FIG. 1C is a partial cross-sectional view taken along line IC--IC of FIG. 1A. FIG. 1D is a partial cross-sectional view along the ID-ID line of FIG. 1A. FIG. 2A is a partial perspective view explaining the method of manufacturing the thermal print head according to this embodiment (No. 1). FIG. 2B is a partial cross-sectional view along line IIB-IIB of FIG. 2A. FIG. 2C is a partial cross-sectional view taken along line IIC-IIC of FIG. 2A. FIG. 2D is a partial cross-sectional view along line IID-IID of FIG. 2A. FIG. 3A is a partial perspective view for explaining the method of manufacturing the thermal print head according to this embodiment (No. 2). FIG. 3B is a partial cross-sectional view along line IIIB-IIIB of FIG. 3A. FIG. 3C is a partial cross-sectional view along line IIIC-IIIC of FIG. 3A. FIG. 3D is a partial cross-sectional view along line IIID-IIID of FIG. 3A. FIG. 4A is a partial perspective view explaining the method of manufacturing the thermal print head according to this embodiment (No. 3). FIG. 4B is a partial cross-sectional view along line IVB-IVB of FIG. 4A. FIG. 4C is a partial cross-sectional view along line IVC-IVC in FIG. 4A. FIG. 4D is a partial cross-sectional view along line IVD-IVD of FIG. 4A. FIG. 5A is a partial perspective view explaining the method of manufacturing the thermal print head according to this embodiment (No. 4). FIG. 5B is a partial cross-sectional view along line VB-VB of FIG. 5A. FIG. 5C is a partial cross-sectional view along line VC-VC of FIG. 5A. FIG. 5D is a partial cross-sectional view along line VD-VD in FIG. 5A. FIG. 6A is a partial perspective view explaining the method of manufacturing the thermal print head according to this embodiment (No. 5). FIG. 6B is a partial cross-sectional view along line VIB--VIB in FIG. 6A. FIG. 6C is a partial cross-sectional view along line VIC--VIC in FIG. 6A. FIG. 6D is a partial cross-sectional view along the VID-VID line in FIG. 6A. FIG. 7A is a partial perspective view illustrating a thermal print head according to a first modified example; FIG. FIG. 7B is a partial cross-sectional view taken along line VIIB--VIIB of FIG. 7A. FIG. 7C is a partial cross-sectional view along line VIIC-VIIC of FIG. 7A. FIG. 7D is a partial cross-sectional view along line VIID-VIID in FIG. 7A. FIG. 8A is a partial perspective view illustrating a thermal print head according to a second modified example. FIG. 8B is a partial cross-sectional view along line VIIIB-VIIIB of FIG. 8A. FIG. 8C is a partial cross-sectional view along line VIIIC-VIIIC of FIG. 8A. FIG. 8D is a partial cross-sectional view along line VIIID-VIIID in FIG. 8A. FIG. 9A is a partial perspective view illustrating a method of manufacturing a thermal print head according to a second modification (No. 1). FIG. 9B is a partial cross-sectional view along line IXB-IXB of FIG. 9A. FIG. 9C is a partial cross-sectional view along line IXC-IXC of FIG. 9A. FIG. 9D is a partial cross-sectional view along line IXD-IXD of FIG. 9A. FIG. 10A is a partial perspective view explaining a method of manufacturing a thermal print head according to a second modification (No. 2). FIG. 10B is a partial cross-sectional view along line XB-XB of FIG. 10A. FIG. 10C is a partial cross-sectional view along line XC-XC of FIG. 10A. FIG. 10D is a partial cross-sectional view along line XD-XD in FIG. 10A. FIG. 11A is a partial perspective view illustrating a method of manufacturing a thermal print head according to the second modification (No. 3). FIG. 11B is a partial cross-sectional view along line XIB-XIB in FIG. 11A. FIG. 11C is a partial cross-sectional view along line XIC-XIC in FIG. 11A. FIG. 11D is a partial cross-sectional view along line XID-XID in FIG. 11A. FIG. 12A is a partial perspective view illustrating a method of manufacturing a thermal print head according to the second modification (No. 4). FIG. 12B is a partial cross-sectional view along line XIIB-XIIB in FIG. 12A. FIG. 12C is a partial cross-sectional view along line XIIC-XIIC in FIG. 12A. FIG. 12D is a partial cross-sectional view along line XIID-XIID of FIG. 12A. FIG. 13A is a partial perspective view illustrating a thermal print head according to a third modified example; FIG. 13B is a partial cross-sectional view along line XIIIB-XIIIB of FIG. 13A. FIG. 13C is a partial cross-sectional view along line XIIIC-XIIIC of FIG. 13A. FIG. 13D is a partial cross-sectional view along line XIIID-XIIID of FIG. 13A. FIG. 14 is a cross-sectional view illustrating a thermal printhead.

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, a heat generating resistor disposed on the heat storage layer, a common electrode disposed on the heat storage layer and having a comb tooth portion, a common electrode disposed on the heat storage layer, the common an individual electrode that is separated from the comb tooth portion of the electrode and faces the comb tooth portion, and in the thickness direction of the heat storage layer, the individual electrode and the comb tooth portion and a second thickness portion having a thickness smaller than that of the first thickness portion, and the heating resistor includes the second thickness portion and the comb teeth of the individual electrode a thermal printhead in contact with the second thickness portion of the portion.

<2> The description of <1>, wherein the heating resistor is arranged on the individual electrode and on the comb tooth at a contact point between the heating resistor, the individual electrode, and the comb tooth. thermal print head.

<3> The thermal print according to <1>, wherein the individual electrode and the common electrode are arranged on the heating resistor at contact points between the heating resistor, the individual electrode, and the comb tooth portion. head.

According to <1> to <3>, disconnection due to agglomeration of metal contained in the metal paste can be suppressed when forming the individual electrodes and the common electrode (during firing). Furthermore, the resistance of the individual electrodes and the common electrode can be reduced. In addition, since the film thicknesses of the individual electrodes and the common electrode in the region overlapping the heating resistor are small, the heat conduction from the heating resistor to the individual electrode and the common electrode can be reduced, and the heating resistor can be kept at a predetermined temperature. It is possible to suppress the increase in the energy required to raise the Therefore, good printing efficiency can be ensured.

<4> The common electrode further has a common portion connected to the comb tooth portion, and the thickness of the common portion is the same as the thickness of the first thickness portion, <1> The thermal print head according to any one of <3>.

According to <4>, the resistance of the common portion can be reduced, and disconnection due to agglomeration of metal can be suppressed.

<5> The thermal printhead according to any one of <1> to <4>, wherein the material of the individual electrodes and the material of the common electrode contain silver or gold.

According to <5>, it is possible to obtain an individual electrode and a common electrode having good metal characteristics and ionization tendency.

<6> The thermal printhead according to any one of <1> to <5>, further comprising a substrate on which the heat storage layer is arranged, wherein the substrate is made of ceramic.

According to <6>, a substrate having excellent heat dissipation properties can be used for the thermal print head.

<7> A thermal printer comprising the thermal print head according to any one of <1> to <6>.

According to <7>, it is possible to obtain a thermal printer that ensures good printing efficiency.

<8> A heat storage layer is formed, and on the heat storage layer, a common electrode having a comb tooth portion and an individual electrode separated from the comb tooth portion and facing the comb tooth portion are respectively arranged as second electrodes. A heat generating resistor is formed on the comb tooth portion and the individual electrode, and the second thickness portion is formed in the thickness direction of the heat storage layer. The film thickness of the film thickness portion is smaller than the film thickness of the first film thickness portion, and the heat generating resistor has the second film thickness portion of the individual electrode and the second film thickness of the comb tooth portion. A method of manufacturing a thermal printhead in contact with a part.

<9> The formation of the individual electrodes and the common electrode includes the step of forming a first electrode layer on the heat storage layer, and forming a second electrode layer on the first electrode layer, wherein the thickness of the first thickness portion is the thickness of the first electrode layer and the thickness of the second electrode layer. The method of manufacturing a thermal print head according to <8>, wherein the thickness of the second thickness portion is the total thickness of the second thickness portion, and the thickness of the first electrode layer.

<10> The formation of the individual electrode and the common electrode includes forming a first electrode layer on the heat storage layer in a thickness direction of the heat storage layer other than a region overlapping with the heat generating resistor; and forming a second electrode layer on the first electrode layer and on the heat storage layer in a region overlapping with the heat generating resistor, wherein the thickness of the first thickness portion is the thickness of the first The thermal print head according to <8>, wherein the thickness of the electrode layer and the thickness of the second electrode layer are the total thickness, and the second thickness portion is the thickness of the second electrode layer. manufacturing method.

<11> Forming a heat storage layer, forming a heat generating resistor on the heat storage layer, forming a common electrode having a comb tooth on the heat storage layer and on the heat generating resistor, and separating the comb tooth from the common electrode, and an individual electrode facing the comb tooth portion is formed so as to have a first film thickness portion and a second film thickness portion, respectively, and the second film thickness portion is formed in the thickness direction of the heat storage layer. The film thickness of the film thickness portion is smaller than the film thickness of the first film thickness portion, and the heat generating resistor has the second film thickness portion of the individual electrode and the second film thickness of the comb tooth portion. A method of manufacturing a thermal printhead in contact with a part.

<12> The formation of the individual electrode and the common electrode includes forming a first electrode layer on the heat storage layer in a thickness direction of the heat storage layer other than a region overlapping with the heat generating resistor; and forming a second electrode layer on the first electrode layer and on the heating resistor, wherein the thickness of the first thickness portion is equal to the thickness of the first electrode layer and the thickness of the first electrode layer. The method of manufacturing a thermal print head according to <11>, wherein the film thickness of the second film thickness portion is the total film thickness of the two electrode layers, and the film thickness of the second film thickness portion is the film thickness of the second electrode layer.

<13> The formation of the individual electrodes and the common electrode includes forming a first electrode layer on the heat storage layer and the heat generating resistor, and and forming a second electrode layer on the first electrode layer other than the overlapping region, wherein the thickness of the first thickness portion is equal to the thickness of the first electrode layer and the thickness of the first electrode layer. The method of manufacturing a thermal print head according to <11>, wherein the thickness of the second thickness portion is the total thickness of the two electrode layers, and the thickness of the second thickness portion is the thickness of the first electrode layer.

According to <8> to <13>, disconnection due to agglomeration of metal contained in the metal paste can be suppressed when forming the individual electrodes and the common electrode (during firing). Furthermore, the resistance of the individual electrodes and the common electrode can be reduced. In addition, since the film thicknesses of the individual electrodes and the common electrode in the region overlapping the heating resistor are small, the heat conduction from the heating resistor to the individual electrode and the common electrode can be reduced, and the heating resistor can be kept at a predetermined temperature. It is possible to suppress the increase in the energy required to raise the Therefore, good printing efficiency can be ensured.

<Thermal print head>
A thermal print head 100 according to this embodiment will be described with reference to the drawings.

FIG. 1A is a partial perspective view showing a thermal printhead 100. FIG. FIG. 1B is a partial cross-sectional view taken along line IB--IB of FIG. 1A. FIG. 1C is a partial cross-sectional view taken along line IC--IC of FIG. 1A. FIG. 1D is a partial cross-sectional view along the ID-ID line of FIG. 1A. 1A to 1D show a portion of a thermal printer (corresponding to one thermal printhead) provided with a plurality of thermal printheads, and in this embodiment, this one thermal printhead is divided into pieces. A thermal print head 100 is used. The thermal print head 100 includes a substrate 15 that is an insulator, a heat storage layer 33 on the substrate 15, a common electrode 32 that is disposed on the heat storage layer 33 and has a comb tooth portion 32A, and is disposed on the heat storage layer 33. The individual electrode 31 is separated from the comb tooth portion 32A of the common electrode 32 and faces the comb tooth portion 32A; , and a protective film 34 covering the individual electrodes 31 , the common electrode 32 , and the heating resistors 40 . FIG. 1A omits illustration of the protective film 34 for easy understanding.

The individual electrode 31 has a first electrode layer 31a and a second electrode layer 31b on the first electrode layer 31a other than the region overlapping the heating resistor 40 in the thickness direction Z, which will be described later. The common electrode 32 has a first electrode layer 32a and a second electrode layer 32b on the first electrode layer 32a other than the region overlapping the heating resistor 40 in the thickness direction Z. In the present embodiment, the portion where the first electrode layer 31a and the second electrode layer 31b are stacked in the thickness direction Z of the heat storage layer 33 is defined as the first thickness portion of the individual electrode 31, and the first A second film thickness portion of the individual electrode 31 is a portion of only the electrode layer 31a. Further, in the present embodiment, a portion of the heat storage layer 33 in the thickness direction Z where the first electrode layer 32a and the second electrode layer 32b are stacked is called a common electrode 32 (including the comb tooth portion 32A and the like). , and a portion of only the first electrode layer 32a is a second thickness portion of the common electrode 32. As shown in FIG. That is, in the individual electrode 31, the film thickness of the second film thickness portion is smaller than that of the first film thickness portion. film thickness is smaller. The heating resistor 40 is in contact with the second film thickness portion of the individual electrode 31 and the second film thickness portion of the comb tooth portion 32</b>A that is part of the common electrode 32 .

The heating resistor 40 includes a plurality of heating resistors 41 that generate heat by current flowing through the individual electrodes 31 and the common electrode 32 . Each heating resistor portion 41 is formed independently between the individual electrode 31 and the common electrode 32 . FIG. 1A omits illustration of the plurality of heating resistors 41 . The plurality of heat generating resistors 41 are linearly arranged on the heat storage layer 33 .

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 (heating resistor portions 41) to which a heating voltage is individually applied in accordance with 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 arranged on the individual electrode 31 and the common electrode 32 (comb tooth portion 32A) at the contact points between the heating resistor 40 and the individual electrode 31 and common electrode 32 (comb tooth portion 32A). 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.

In this embodiment, the main scanning direction X is the direction in which the heating resistor 40 extends linearly, 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, and the substrate is the substrate. Let the direction corresponding to the thickness of 15 be the thickness direction Z. 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. Also, the direction in which the heat storage layer 33 is located when viewed from the substrate 15 is defined as the upward direction, and the direction in which the substrate 15 is located when viewed from the heat storage layer 33 is defined as the downward direction.

In this specification and the like, "electrically connected" includes the case of being connected via "something that has some electrical effect". Here, "having some kind of electrical action" is not particularly limited as long as it enables transmission and reception of electrical signals between connection objects. For example, "things having some electrical action" include electrodes, wirings, switching elements, resistive elements, inductors, capacitive elements, and other elements having various functions.

The substrate 15 is an insulator, and is made of, for example, ceramic or a single crystal semiconductor. As the ceramic, for example, alumina or the like can be used. As the single crystal semiconductor substrate, for example, a silicon substrate 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 . For example, silicon oxide and silicon nitride, which are main components of glass, can be used for the heat storage layer 33 . The dimension of the heat storage layer 33 in the thickness direction Z is not particularly limited, and is, for example, 5 to 200 μm, preferably 10 to 30 μm.

An individual electrode 31 and a common electrode 32 made of metal paste are provided on the heat storage layer 33 . The individual electrodes 31 and the common electrode 32 are obtained by applying the metal paste, which is the material of the individual electrodes 31 and the common electrode 32 , to the heat storage layer 33 by screen printing or the like, and then firing to form an electrode pattern. In addition to screen printing, a lithography process may be performed to form the individual electrodes 31 and the common electrode 32 .

As the metal paste, for example, a paste containing metal particles such as copper, silver, palladium, iridium, platinum, and gold can be used. Moreover, an organometallic compound can also be used as a metal paste. From the viewpoint of metal properties and ionization tendency, silver and gold are preferable, and from the viewpoint of metal properties, ionization tendency and cost reduction, silver is more preferable. 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.

The individual electrode 31 has a first electrode layer 31a and a second electrode layer 31b. The common electrode 32 has a first electrode layer 32a and a second electrode layer 32b. The first electrode layer 31a and the first electrode layer 32a are preferably formed using a paste containing metal particles having a smaller particle size than those of the second electrode layer 31b and the second electrode layer 32b. For example, it is preferably formed from a resinate paste containing silver. The dimension in the thickness direction Z of the first electrode layers 31a and 32a is not particularly limited, and is, for example, 1 to 3 μm, preferably 1.5 to 2.5 μm.

The second electrode layer 31b is arranged on a part of the first electrode layer 31a. It is arranged on the electrode layer 31a. The second electrode layer 32b is arranged on a part of the first electrode layer 32a. It is arranged on the electrode layer 32a. The second electrode layer 31b and the second electrode layer 32b are made of a paste containing metal particles having a larger particle size than the metal particles contained in the paste used to form the first electrode layer 31a and the first electrode layer 32a. For example, it is preferably formed from a resinate paste containing silver particles. The dimensions in the thickness direction Z of the second electrode layers 31b and 32b are not particularly limited, and are, for example, 1 to 5 μm, preferably 2 to 4 μm.

The metal particles contained in the paste used to form the first electrode layer 31a and the first electrode layer 32a are more granular than the metal particles contained in the paste used to form the second electrode layer 31b and the second electrode layer 32b. Since the diameter is small, the average surface roughness of the first electrode layer 31a and the first electrode layer 32a is smaller than the average surface roughness of the second electrode layer 31b and the second electrode layer 32b. The average surface roughness can be determined according to JIS B 0601:2013 and ISO 25178, for example.

By arranging the electrode layer having a large average surface roughness on the upper side in contact with the wire or the like, bonding characteristics such as adhesion are improved, which is preferable. That is, the second electrode layer 31b and the second electrode layer 32b having relatively large average surface roughness are formed on the first electrode layer 31a and the first electrode layer 32a having relatively small average surface roughness. By arranging them respectively, the contact between the wire and the second electrode layer 31b or the second electrode layer 32b in the individual pad portion (not shown) is widened, and the bonding characteristics are improved.

In the individual electrode 31, the thickness of the first thickness portion is the sum of the thickness of the first electrode layer 31a and the thickness of the second electrode layer 31b, and the thickness of the second thickness portion is , the film thickness of the first electrode layer 31a. In the common electrode 32, the thickness of the first thickness portion is the sum of the thickness of the first electrode layer 32a and the thickness of the second electrode layer 32b, and the thickness of the second thickness portion is , is the film thickness of the first electrode layer 32a. Note that when the first electrode layer 31a (or the first electrode layer 32a) and the second electrode layer 31b (or the second electrode layer 32b) are made of the same material and the boundary is difficult to distinguish, the second electrode layer 31a (or the first electrode layer 32a) may The first electrode layer 31a (or the first The interface between the electrode layer 32a) and the second electrode layer 31b (or the second electrode layer 32b).

The first thickness portion of the individual electrode 31 is thicker than the second thickness portion of the individual electrode 31 , and the first thickness portion of the common electrode 32 is thicker than the second thickness portion of the common electrode 32 . Since the thickness is large, disconnection due to agglomeration of metal contained in the metal paste can be suppressed when forming the individual electrodes 31 and the common electrode 32 (during firing). Furthermore, the resistance of the individual electrodes 31 and the common electrode 32 can be reduced. The second film thickness portion of the individual electrode 31 and the second film thickness portion of the common electrode 32, which are regions overlapping with the heating resistor 40 described later, are the first film thickness portion of the individual electrode 31 and the common electrode 32, respectively. Since the film thickness is smaller than the first film thickness portion 32, heat conduction from the heat generating resistor 40 to the individual electrode 31 and the common electrode 32 can be reduced, and the temperature of the heat generating resistor 40 is raised to a predetermined temperature. can suppress the increase in the energy required for Therefore, good printing efficiency can be ensured.

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 portion of each individual electrode 31 is connected to an individual pad portion (not shown).

The 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. The common electrode 32 has a comb tooth portion 32A and a common portion 32B connected to the comb tooth portion 32A. The common portion 32B is formed in the main scanning direction X along the edge of the substrate 15 on the upper side. In the sub-scanning direction Y, the direction in which the common portion 32B of the common electrode 32 is located when viewed from the individual electrodes 31 is defined as the upper side in the sub-scanning direction Y. As shown in FIG. Each comb tooth portion 32A has a strip shape extending in the sub-scanning direction Y. As shown in FIG. The tip of each comb tooth portion 32A faces the tip of each individual electrode 31 along the sub-scanning direction Y with a predetermined gap therebetween. With such a configuration, the pitch of the heating resistors 40 can be narrowed, so that high-definition printing is possible.

The heating resistor 40 can be formed by firing a resistor paste. In this embodiment, the dimension in the thickness direction Z of the heating resistor 40 is, for example, about 1 to 10 μm.

The heating resistor 40 and the like are covered with a protective film 34, and the protective film 34 protects the heating resistor 40 and the like from abrasion, 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 2 to 8 μm. A thickness within this range is preferable because it is possible to obtain the thermal print head 100 capable of suppressing defective pressure resistance and maintaining good print quality.

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

As shown in FIGS. 2A to 2D, 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 to the substrate 15 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. 3A to 3D, on the heat storage layer 33, the first electrode layer 31a of the individual electrode 31 and the first electrode layer 32a of the common electrode 32 are formed. The first electrode layer 31a and the first electrode layer 32a are obtained by applying the above metal paste having a relatively small particle size to the heat storage layer 33 by screen printing or the like, then firing it, and performing a lithography process. The dimension in the thickness direction Z of the first electrode layers 31a and 32a is, for example, 1 to 3 μm.

Next, as shown in FIGS. 4A to 4D, a second electrode layer 31b is formed on the first electrode layer 31a other than the region overlapping the heating resistor 40 to be formed later, and the heating resistor 40 and the heating resistor 40 are formed. A second electrode layer 32b is formed on the first electrode layer 32a other than the overlapping region. The second electrode layer 31b and the second electrode layer 32b are made of a paste containing metal particles having a larger particle size than the metal particles contained in the paste used to form the first electrode layer 31a and the first electrode layer 32a. It is obtained by coating the first electrode layer 31a and the first electrode layer 32a by screen printing or the like, then baking, and performing a lithography process. The dimensions in the thickness direction Z of the second electrode layers 31b and 32b are, for example, 1 to 5 μm.

Through the above steps, a first film thickness portion where the first electrode layer 31a and the second electrode layer 31b are laminated, and a second film thickness portion where only the first electrode layer 31a is formed. A first film thickness portion, which is a portion where the first electrode layer 32a and the second electrode layer 32b are laminated, and a first film thickness portion. It is possible to form the common electrode 32 having a second film thickness portion which is only a portion of the electrode layer 32a.

The method of forming the individual electrodes 31 and the common electrode 32 is not limited to this. After applying the metal paste to be the second electrode layer 31b and the second electrode layer 32b to the metal paste to be the first electrode layer 31a and the first electrode layer 32a by screen printing or the like, these metal pastes are applied. They may be baked together and formed by performing a lithography process. Also, a part of the electrode layer (the region overlapping with the heat generating resistor 40 to be formed later) is removed by etching or the like, and the individual electrodes having the above-described first film thickness portion and second film thickness portion are formed. An electrode 31 and a common electrode 32 may be formed.

Next, as shown in FIGS. 5A to 5D, resistor paste is formed to form the heating resistor 40 (heating resistor portion 41). The resistor paste contains, for example, ruthenium oxide. Next, the heating resistor 40 (heating resistor portion 41) is formed by firing the resistor paste described above.

Next, as shown in FIGS. 6A to 6D, 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 100 of the present embodiment can be manufactured.

According to the present embodiment, disconnection due to agglomeration of metal contained in the metal paste can be suppressed when forming the individual electrodes 31 and the common electrode 32 (during firing). Furthermore, the resistance of the individual electrodes 31 and the common electrode 32 can be reduced. In addition, since the film thicknesses of the individual electrodes 31 and the common electrode 32 in the regions overlapping the heating resistors 40 are small, heat conduction from the heating resistors 40 to the individual electrodes 31 and the common electrode 32 can be reduced. An increase in the energy required to raise the temperature of the resistor 40 to a predetermined temperature can be suppressed. Therefore, good printing efficiency can be ensured.

<First modification>
A configuration of a thermal print head 100A according to this modification will be described.

FIG. 7A is a partial perspective view showing the thermal printhead 100A. FIG. 7B is a partial cross-sectional view taken along line VIIB--VIIB of FIG. 7A. FIG. 7C is a partial cross-sectional view along line VIIC-VIIC of FIG. 7A. FIG. 7D is a partial cross-sectional view along line VIID-VIID in FIG. 7A. The thermal print head 100A includes a substrate 15 that is an insulator, a heat storage layer 33 on the substrate 15, a common electrode 32 that is disposed on the heat storage layer 33 and has a comb tooth portion 32A, and is disposed on the heat storage layer 33. The individual electrode 31 is separated from the comb tooth portion 32A of the common electrode 32 and faces the comb tooth portion 32A; , and a protective film 34 covering the individual electrodes 31 , the common electrode 32 , and the heating resistors 40 . FIG. 7A omits illustration of the protective film 34 for easy understanding.

The individual electrode 31 has a first electrode layer 31a and a second electrode layer 31b on the first electrode layer 31a. The common electrode 32 has a first electrode layer 32a and a second electrode layer 32b on the first electrode layer 32a. In this actual modification, the portion where the first electrode layer 31a and the second electrode layer 31b are laminated in the thickness direction Z of the heat storage layer 33 is defined as the first film thickness portion of the individual electrode 31, A portion of only the electrode layer 31b of No. 2 is used as a second film thickness portion of the individual electrode 31 . In addition, in this actual modification, the portion where the first electrode layer 32a and the second electrode layer 32b are laminated in the thickness direction Z of the heat storage layer 33 is the common electrode 32 (including the comb tooth portion 32A and the like). ), and the portion of only the second electrode layer 32b is defined as the second thickness portion of the common electrode 32. As shown in FIG. The heating resistor 40 is in contact with the second film thickness portion of the individual electrode 31 and the second film thickness portion of the comb tooth portion 32</b>A that is part of the common electrode 32 . The difference of the thermal print head 100A according to this modification from the thermal print head 100 shown in FIGS. and that the second film thickness portion of the common electrode 32 consists of only the second electrode layer 32b. In this modified example, the above description is used for common points with the thermal print head 100 shown in FIGS. 1A to 1D, and different points will be described below.

The individual electrode 31 has a first electrode layer 31a and a second electrode layer 31b. The common electrode 32 has a first electrode layer 32a and a second electrode layer 32b. The first electrode layer 31a and the first electrode layer 32a are arranged on at least a portion of the heat storage layer 33 other than the region overlapping the heating resistor 40 . The second electrode layer 31b is arranged on the heat storage layer 33 in the region overlapping the first electrode layer 31a and the heating resistor 40 . The second electrode layer 32b is arranged on the first electrode layer 32a and on the heat storage layer 33 in a region overlapping with the heating resistor 40 . Since the heating resistor 40 is in contact with the second electrode layer 31b and the second electrode layer 32b having a large average surface roughness, the heating resistor 40 and the second electrode layer 31b or the second electrode layer 32b contact with becomes wider, and good adhesion can be obtained in these contacts.

In the individual electrode 31 according to this modification, the thickness of the first thickness portion is the sum of the thickness of the first electrode layer 31a and the thickness of the second electrode layer 31b. is the film thickness of the second electrode layer 31b. In the common electrode 32 in this modified example, the thickness of the first thickness portion is the sum of the thickness of the first electrode layer 32a and the thickness of the second electrode layer 32b. is the film thickness of the second electrode layer 32b.

According to this modified example, disconnection due to agglomeration of metal contained in the metal paste can be suppressed when forming the individual electrodes 31 and the common electrode 32 (during firing). Furthermore, the resistance of the individual electrodes 31 and the common electrode 32 can be reduced. In addition, since the film thicknesses of the individual electrodes 31 and the common electrode 32 in the regions overlapping the heating resistors 40 are small, heat conduction from the heating resistors 40 to the individual electrodes 31 and the common electrode 32 can be reduced. An increase in the energy required to raise the temperature of the resistor 40 to a predetermined temperature can be suppressed. Therefore, good printing efficiency can be ensured.

<Second Modification>
A configuration of a thermal print head 100B according to this modification will be described.

FIG. 8A is a partial perspective view showing the thermal printhead 100B. FIG. 8B is a partial cross-sectional view along line VIIIB-VIIIB of FIG. 8A. FIG. 8C is a partial cross-sectional view along line VIIIC-VIIIC of FIG. 8A. FIG. 8D is a partial cross-sectional view along line VIIID-VIIID in FIG. 8A. The thermal print head 100B includes a substrate 15 that is an insulator, a heat storage layer 33 on the substrate 15, a heat generating resistor 40 on the heat storage layer 33, and a comb tooth portion 32A on the heat storage layer 33 and on the heat generating resistor 40. a common electrode 32 having a common electrode 32, individual electrodes 31 on the heat storage layer 33 and on the heating resistor 40, which are separated from the comb tooth portion 32A of the common electrode 32 and face the comb tooth portion 32A, the heat storage layer 33, A protective film 34 covering the heating resistor 40 , the individual electrode 31 , and the common electrode 32 is provided. FIG. 8A omits illustration of the protective film 34 for easy understanding. A thermal print head 100B according to this modification differs from the thermal print head 100 shown in FIGS. The point is that In this modified example, the above description is used for common points with the thermal print head 100 shown in FIGS. 1A to 1D, and different points will be described below.

The individual electrode 31 is arranged on the heat storage layer 33 and the heating resistor 40, and has a first electrode layer 31a and a second electrode layer 31b. The common electrode 32 is arranged on the heat storage layer 33 and the heating resistor 40, and has a first electrode layer 32a and a second electrode layer 32b. The first electrode layer 31 a and the first electrode layer 32 a are arranged on the heat storage layer 33 and the heating resistor 40 . The second electrode layer 31b is arranged on the first electrode layer 31a other than the region overlapping the heating resistor 40. As shown in FIG. The second electrode layer 32b is arranged on the first electrode layer 32a other than the region overlapping the heating resistor 40. As shown in FIG.

In the individual electrode 31 according to this modification, the thickness of the first thickness portion is the sum of the thickness of the first electrode layer 31a and the thickness of the second electrode layer 31b. is the film thickness of the first electrode layer 31a. In the common electrode 32 in this modified example, the thickness of the first thickness portion is the sum of the thickness of the first electrode layer 32a and the thickness of the second electrode layer 32b. is the film thickness of the first electrode layer 32a.

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

First, as shown in FIGS. 2A to 2D, the substrate 15 is prepared and the heat storage layer 33 is formed on the substrate 15 . Next, as shown in FIGS. 9A to 9D, resistor paste is formed on the heat storage layer 33 to form the heat generating resistor 40 (heat generating resistor portion 41). The resistor paste contains, for example, ruthenium oxide. Next, the heating resistor 40 (heating resistor portion 41) is formed by firing the resistor paste described above.

Next, as shown in FIGS. 10A to 10D, the first electrode layer 31a of the individual electrode 31 and the first electrode layer 32a of the common electrode 32 are formed on the heat storage layer 33 and the heating resistor . The first electrode layer 31a and the first electrode layer 32a are obtained by applying the above metal paste having a small particle size to the heat storage layer 33 and the heating resistor 40 by screen printing or the like, followed by firing and lithography. be done. The dimension in the thickness direction Z of the first electrode layers 31a and 32a is, for example, 1 to 3 μm.

Next, as shown in FIGS. 11A to 11D, a second electrode layer 31b is formed on the first electrode layer 31a other than the region overlapping the heating resistor 40, and the second electrode layer 31b is formed on the region other than the region overlapping the heating resistor 40. A second electrode layer 32b is formed on the first electrode layer 32a. The second electrode layer 31b and the second electrode layer 32b are made of a paste containing metal particles having a larger particle size than the metal particles contained in the paste used to form the first electrode layer 31a and the first electrode layer 32a. It is obtained by coating the first electrode layer 31a and the first electrode layer 32a by screen printing or the like, and then performing baking and a lithography process. The dimensions in the thickness direction Z of the second electrode layers 31b and 32b are, for example, 1 to 5 μm.

Through the above steps, a first film thickness portion where the first electrode layer 31a and the second electrode layer 31b are laminated, and a second film thickness portion where only the first electrode layer 31a is formed. A first film thickness portion, which is a portion where the first electrode layer 32a and the second electrode layer 32b are laminated, and a first film thickness portion. It is possible to form the common electrode 32 having a second film thickness portion which is only a portion of the electrode layer 32a.

Next, as shown in FIGS. 12A to 12D, 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 above steps, the thermal print head 100B of this embodiment can be manufactured.

According to this modified example, disconnection due to agglomeration of metal contained in the metal paste can be suppressed when forming the individual electrodes 31 and the common electrode 32 (during firing). Furthermore, the resistance of the individual electrodes 31 and the common electrode 32 can be reduced. In addition, since the film thicknesses of the individual electrodes 31 and the common electrode 32 in the regions overlapping the heating resistors 40 are small, heat conduction from the heating resistors 40 to the individual electrodes 31 and the common electrode 32 can be reduced. An increase in the energy required to raise the temperature of the resistor 40 to a predetermined temperature can be suppressed. Therefore, good printing efficiency can be ensured.

<Third Modification>
A configuration of a thermal print head 100C according to this modification will be described.

FIG. 13A is a partial perspective view showing the thermal print head 100C. FIG. 13B is a partial cross-sectional view along line XIIIB-XIIIB of FIG. 13A. FIG. 13C is a partial cross-sectional view along line XIIIC-XIIIC of FIG. 13A. FIG. 13D is a partial cross-sectional view along line XIIID-XIIID of FIG. 13A. The thermal print head 100C includes a substrate 15 that is an insulator, a heat storage layer 33 on the substrate 15, a heat generating resistor 40 on the heat storage layer 33, and a comb tooth portion 32A on the heat storage layer 33 and on the heat generating resistor 40. a common electrode 32 having a common electrode 32, individual electrodes 31 on the heat storage layer 33 and on the heating resistor 40, which are separated from the comb tooth portion 32A of the common electrode 32 and face the comb tooth portion 32A, the heat storage layer 33, A protective film 34 covering the heating resistor 40 , the individual electrode 31 , and the common electrode 32 is provided. FIG. 13A omits illustration of the protective film 34 for easy understanding. A thermal print head 100C according to this modification differs from the thermal print head 100A shown in FIGS. The point is that In this modified example, the above description is used for common points with the thermal print head 100A shown in FIGS. 7A to 7D, and different points are described below.

The individual electrode 31 is arranged on the heat storage layer 33 and the heating resistor 40, and has a first electrode layer 31a and a second electrode layer 31b. The common electrode 32 is arranged on the heat storage layer 33 and the heating resistor 40, and has a first electrode layer 32a and a second electrode layer 32b. In this actual modification, the portion where the first electrode layer 31a and the second electrode layer 31b are laminated in the thickness direction Z of the heat storage layer 33 is defined as the first film thickness portion of the individual electrode 31, A portion of only the electrode layer 31b of No. 2 is used as a second film thickness portion of the individual electrode 31 . In addition, in this actual modification, the portion where the first electrode layer 32a and the second electrode layer 32b are laminated in the thickness direction Z of the heat storage layer 33 is the common electrode 32 (including the comb tooth portion 32A and the like). ), and the portion of only the second electrode layer 32b is defined as the second thickness portion of the common electrode 32. As shown in FIG. The heating resistor 40 is in contact with the second film thickness portion of the individual electrode 31 and the second film thickness portion of the comb tooth portion 32</b>A that is part of the common electrode 32 . Since the heating resistor 40 is in contact with the second electrode layer 31b and the second electrode layer 32b having a large average surface roughness, the heating resistor 40 and the second electrode layer 31b or the second electrode layer 32b contact with becomes wider, and good adhesion can be obtained in these contacts.

In the individual electrode 31 according to this modification, the thickness of the first thickness portion is the sum of the thickness of the first electrode layer 31a and the thickness of the second electrode layer 31b. is the film thickness of the second electrode layer 31b. In the common electrode 32 in this modified example, the thickness of the first thickness portion is the sum of the thickness of the first electrode layer 32a and the thickness of the second electrode layer 32b. is the film thickness of the second electrode layer 32b.

According to this modified example, disconnection due to agglomeration of metal contained in the metal paste can be suppressed when forming the individual electrodes 31 and the common electrode 32 (during firing). Furthermore, the resistance of the individual electrodes 31 and the common electrode 32 can be reduced. In addition, since the film thicknesses of the individual electrodes 31 and the common electrode 32 in the regions overlapping the heating resistors 40 are small, heat conduction from the heating resistors 40 to the individual electrodes 31 and the common electrode 32 can be reduced. An increase in the energy required to raise the temperature of the resistor 40 to a predetermined temperature can be suppressed. Therefore, good printing efficiency can be ensured.

(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.

<Thermal printer>
Further, as shown in FIG. 14, the thermal print head (for example, the thermal print head 100) 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, a drive IC 7, A plurality of wires 81 , a resin portion 82 and a connector 59 are provided. 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 printing 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 drive 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 .

A thermal printer can comprise a thermal printhead as 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. Examples of print media include thermal paper for producing bar code 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 measuring 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, it is possible to check the life of the heat generating resistor 41 and the presence or absence of a malfunctioning heat generating resistor 41 . 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 .

Moreover, the thermal print head is not limited to the above-described configuration. For example, the configuration may be one in which the drive IC 7 is directly mounted on the substrate 15 without providing the connection substrate 5, or a configuration in which the wires 81 are not provided by flip-chip mounting. or a configuration in which the heat radiating member 8 is not provided.

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

When printing onto a print medium, the connector 59 is supplied with a first potential, which is an input signal, from the main power supply circuit. 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 first potential is applied to the connector 59 from the main power supply circuit, 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, the second potential is applied to the connector 59 from the measuring circuit. 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 second potential. As described above, when the second potential is applied to the connector 59 from the main power supply circuit, 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 the above, it is possible to obtain a thermal printer that ensures good printing efficiency.

5 connection board 7 drive IC
8 heat dissipation member 15 substrate 31 individual electrodes 31a, 32a first electrode layers 31b, 32b second electrode layer 32 common electrode 32A comb tooth portion 32B common portion 33 heat storage layer 34 protective film 40 heating resistor 41 heating resistor portion 59 connector 81 wire 82 resin part 91 platen roller 92 print medium 100, 100A, 100B, 100C thermal print head

Claims (13)

a heat storage layer;
a heating resistor disposed on the heat storage layer;
a common electrode disposed on the heat storage layer and having a comb tooth;
an individual electrode disposed on the heat storage layer, separated from the comb tooth portion of the common electrode, and facing the comb tooth portion;
In the thickness direction of the heat storage layer, the individual electrode and the comb tooth portion each have a first thickness portion and a second thickness portion having a thickness smaller than that of the first thickness portion. death,
The thermal print head, wherein the heating resistor is in contact with the second film thickness portion of the individual electrode and the second film thickness portion of the comb tooth portion. 2. The thermal printhead according to claim 1, wherein the heating resistor is arranged on the individual electrode and on the comb tooth portion at contact points between the heating resistor and the individual electrode and the comb tooth portion. . 2. The thermal printhead according to claim 1, wherein the individual electrodes and the common electrode are arranged on the heating resistor at contact points between the heating resistor, the individual electrodes, and the comb tooth portion. The common electrode further has a common portion connected to the comb tooth portion,
4. The thermal print head according to claim 1, wherein the thickness of said common portion is the same as the thickness of said first thickness portion. The thermal printhead according to any one of claims 1 to 4, wherein the material of the individual electrodes and the material of the common electrode comprise silver or gold. further comprising a substrate on which the heat storage layer is arranged;
6. The thermal printhead according to any one of claims 1 to 5, wherein said substrate is made of ceramic. A thermal printer comprising the thermal print head according to any one of claims 1 to 6. forming a heat storage layer,
A common electrode having a comb tooth portion and an individual electrode separated from the comb tooth portion and facing the comb tooth portion are provided on the heat storage layer as a first film thickness portion and a second film thickness portion, respectively. Formed so as to have a film thickness portion,
forming a heating resistor on the comb tooth portion and on the individual electrode;
In the thickness direction of the heat storage layer, the film thickness of the second film thickness portion is smaller than the film thickness of the first film thickness portion,
The method of manufacturing a thermal print head, wherein the heating resistor is in contact with the second film thickness portion of the individual electrode and the second film thickness portion of the comb tooth portion. Forming the individual electrodes and the common electrode includes:
forming a first electrode layer on the heat storage layer;
forming a second electrode layer on the first electrode layer in a thickness direction of the heat storage layer other than a region overlapping with the heat generating resistor;
The thickness of the first thickness portion is the sum of the thickness of the first electrode layer and the thickness of the second electrode layer,
9. The method of manufacturing a thermal print head according to claim 8, wherein the film thickness of said second film thickness portion is the film thickness of said first electrode layer. Forming the individual electrodes and the common electrode includes:
forming a first electrode layer on the heat storage layer in a thickness direction of the heat storage layer other than a region overlapping with the heat generating resistor;
forming a second electrode layer on the first electrode layer and on the heat storage layer in a region overlapping with the heating resistor;
The thickness of the first thickness portion is the sum of the thickness of the first electrode layer and the thickness of the second electrode layer,
9. The method of manufacturing a thermal print head according to claim 8, wherein said second film thickness portion is the film thickness of said second electrode layer. forming a heat storage layer,
forming a heating resistor on the heat storage layer;
A common electrode having a comb tooth portion and an individual electrode separated from the comb tooth portion and facing the comb tooth portion are formed as first films on the heat storage layer and the heat generating resistor, respectively. formed to have a thick portion and a second thick portion;
In the thickness direction of the heat storage layer, the film thickness of the second film thickness portion is smaller than the film thickness of the first film thickness portion,
The method of manufacturing a thermal print head, wherein the heating resistor is in contact with the second film thickness portion of the individual electrode and the second film thickness portion of the comb tooth portion. Forming the individual electrodes and the common electrode includes:
forming a first electrode layer on the heat storage layer in a thickness direction of the heat storage layer other than a region overlapping with the heat generating resistor;
forming a second electrode layer on the first electrode layer and on the heating resistor;
The thickness of the first thickness portion is the sum of the thickness of the first electrode layer and the thickness of the second electrode layer,
12. The method of manufacturing a thermal print head according to claim 11, wherein the film thickness of said second film thickness portion is the film thickness of said second electrode layer. Forming the individual electrodes and the common electrode includes:
forming a first electrode layer on the heat storage layer and the heating resistor;
forming a second electrode layer on the first electrode layer in a thickness direction of the heat storage layer other than a region overlapping with the heat generating resistor;
The thickness of the first thickness portion is the sum of the thickness of the first electrode layer and the thickness of the second electrode layer,
12. The method of manufacturing a thermal printhead according to claim 11, wherein the film thickness of said second film thickness portion is the film thickness of said first electrode layer.

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