JP5273786B2 - Thermal head, printer, and thermal head manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve heat generating efficiency and strength to external load. <P>SOLUTION: This thermal head 1 includes a support substrate 3 having a recess 2 in the surface; a heat storage layer 5 joined to the surface of the support substrate 3; and a heating resistor provided in a region, facing the recess 2 of the support substrate 3, on the heat storage layer 5. A projecting part 2A contacting the heat storage layer 5 to limit the flexure of the heat storage layer 5 when the heating resistor is pressurized by load of a predetermined value or more is provided inside a cavity part formed between the support substrate 3 and the heat storage layer 5 by the recess 2. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a thermal head, a printer, and a method for manufacturing a thermal head.

  Conventionally, it is used in thermal printers that are often mounted on small information equipment terminals represented by small handy terminals, and for performing printing on a thermal recording medium by selectively driving a plurality of heating elements based on printing data. A thermal head is known (see, for example, Patent Document 1).

  In order to increase the efficiency of the thermal head, there is a method in which a heat insulating layer is formed under the heating portion of the heating resistor. By forming a heat insulating layer under the heat generating part, the amount of heat transmitted to the wear-resistant layer above the heat generating part out of the amount of heat generated by the heat generating resistor is transferred to the heat storage layer below the heat generating part. Since it becomes larger than the downward heat transfer amount, the energy efficiency required at the time of printing becomes good. In the thermal head described in Patent Document 1, a cavity is provided in a layer below the heat generating part of the heating resistor, and by making this cavity function as a hollow heat insulating layer, the amount of electric heat above the amount of electric heat below is reduced. Enlarging the energy efficiency.

  Further, in a printer equipped with a thermal head, the thermal paper is pressed against the head portion on the surface of the wear-resistant layer above the heat generating portion with a predetermined pressing force by a platen roller. Therefore, the thermal head is required to have a heat generation efficiency that improves the printing quality as described above, and to have a strength that can withstand the pressing force of the platen roller.

JP-A-6-166197

  However, in the conventional thermal head, if the cavity is enlarged to reduce the thickness of the heat storage layer between the heating resistor and the cavity in order to increase the heat insulation performance of the substrate, an external load is applied to the heating resistor. In this case, excessive deflection occurs in the heat storage layer. And when the tensile stress by bending becomes more than the fracture stress of glass, there exists a problem that a thermal storage layer will be damaged. In addition, when a large deflection occurs in the heat storage layer due to the pressing force of the platen roller, there is a problem that the contact state between the thermal paper and the head portion is deteriorated, the contact pressure is lowered, and heat is not easily transmitted to the thermal paper. .

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a thermal head, a printer, and a method for manufacturing a thermal head that achieves improvement in heat generation efficiency and improvement in strength against an external load. .

In order to achieve the above object, the present invention provides the following means.
The present invention includes a substrate having a recess on a surface, a heat storage layer bonded to the surface of the substrate, and a plurality of heating resistors provided in a region facing the recess of the substrate on the heat storage layer. The recess has a size such that the plurality of heating resistors face each other, and the heating resistor is not less than a predetermined amount inside a hollow portion formed between the substrate and the heat storage layer by the recess. There is provided a thermal head provided with a deflection limiting portion that comes into contact with the heat storage layer when pressed by the load of the heat storage layer and limits the deflection of the heat storage layer.

According to the present invention, the cavity functions as a hollow heat insulating layer, and it is possible to suppress the heat generated in the heating resistor from being transmitted to the substrate through the heat storage layer. As a result, the amount of heat that is conducted to the upper side of the heating resistor and used for printing or the like increases, and the heat generation efficiency can be improved.
In addition, when an excessive load is applied to the heating resistor, the deflection limiting portion limits the deflection of the heat storage layer by contacting the heat storage layer. Thereby, damage to the heat storage layer can be prevented.

  In the above invention, the deflection limiting portion is formed in a shape protruding from the bottom surface of the hollow portion toward the heat storage layer, and the heat storage layer can contact the heat storage layer within a range of elastic deformation. It is good also as having the clearance gap within the range.

  By comprising in this way, when a deflection | deviation arises in a thermal storage layer, a thermal storage layer can contact a deflection | deviation control part, and can suppress the deformation | transformation of a thermal storage layer within the range of elastic deformation. Moreover, a high heat insulation performance can be maintained because a deflection | deviation control part always has a clearance gap between heat storage layers. The deflection control unit may have a columnar shape or a wall shape.

In the above aspect, wherein the gap between the deflection control unit the heat storage layer is less than about 0.1 [mu] m or more to about 1 [mu] m, or less thickness of about 10μm of the heat storage layer for closing the opening of the recess It is good also as being.

Moreover, in the said invention, it is good also as having the curved surface shape which the periphery of the said recessed part in the said surface of the said board | curve curves in the direction which leaves | separates gradually from the said thermal storage layer toward the inner side of this recessed part.
By configuring in this way, when an external load is applied to the heat storage layer that closes the opening of the recess and bending occurs, stress concentration applied to the heat storage layer in the vicinity of the recess on the substrate surface can be reduced.

  The present invention provides a printer comprising the thermal head of the present invention and a pressurizing mechanism that presses an object to be printed against the heating resistor of the general thermal head.

  According to the present invention, the heat generation efficiency of the thermal head is high, and the power consumption during printing on printed matter can be reduced. Further, by limiting the deflection of the heat storage layer due to the pressing force of the pressurizing mechanism by the deflection control unit, it is possible to prevent the heat storage layer from being damaged and to reliably bring the heating resistor into contact with the printing object and to transmit heat. . Therefore, it is possible to perform printing with excellent print quality with less power.

The present invention, the substrate on the surface of the substrate, have a protrusion on the bottom surface, a concave portion forming step of forming a recess sized to face the plurality of heating resistors of, the said recess by the concave portion forming step is formed And a heat generating resistor forming step of forming a plurality of heat generating resistors on the heat storage layer so as to oppose the concave portions, and the bonding step includes the heat melting layer. There is provided a method for manufacturing a thermal head in which a gap is formed between the protruding portion and the heat storage layer by utilizing expansion of gas in the recess and softening of the substrate and the heat storage layer during wearing.

  According to the present invention, in the bonding step, the concave portion of the substrate formed by the concave portion forming step is covered with the heat storage layer, so that a cavity is formed between the substrate and the heat storage layer. This hollow portion functions as a hollow heat insulating layer and suppresses heat generated in the heat generating portion of the heat generating resistor from being transmitted to the substrate through the heat storage layer, so that a thermal head with high energy efficiency can be manufactured. Moreover, since the thickness of the cavity is determined by the depth of the recess, the thickness of the hollow heat insulating layer can be easily controlled.

  Further, in the joining step, a special step for forming the gap can be omitted by forming the gap between the protruding portion and the heat storage layer at the time of thermal fusion between the substrate and the heat storage layer. Therefore, the number of manufacturing steps can be reduced and the manufacture of the thermal head can be simplified.

In the said invention, the said joining process is good also as forming the said clearance gap so that the said thermal storage layer may contact the said protrusion part within the range of the elastic deformation of the said thermal storage layer.
By comprising in this way, the thermal head which prevents the damage of a thermal storage layer can be manufactured.

  In the invention described above, the bonding step may form a curved shape that curves around the recess on the surface of the substrate in a direction gradually away from the heat storage layer toward the inside of the recess. .

  With this configuration, it is possible to manufacture a thermal head in which stress concentration applied to the heat storage layer is reduced in the vicinity of the recess on the surface of the substrate even when the heat storage layer that closes the opening of the recess is bent due to an external load. .

  According to the present invention, there is an effect that improvement in heat generation efficiency and improvement in strength against an external load can be realized.

[First Embodiment]
Hereinafter, a printer 10 and a thermal head 1 according to a first embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the thermal printer 10 according to the present embodiment includes a main body frame 11, a horizontally disposed platen roller 13, a thermal head 1 disposed to face the outer peripheral surface of the platen roller 13, and a thermal head 1. A heat-sink 15 that supports the paper (see FIG. 3), a paper feed mechanism 17 that feeds a printing object such as the thermal paper 12 between the platen roller 13 and the thermal head 1, and the thermal head 1 to the thermal paper 12. A pressurizing mechanism 19 is provided that presses it with a predetermined pressing force.

The platen roller 13 is pressed against the thermal head 1 and the thermal paper 12 by the operation of the pressure mechanism 19. As a result, the load of the platen roller 13 is applied to the thermal head 1 via the thermal paper 12.
The heat radiating plate 15 is a plate-like member made of, for example, a metal such as aluminum, resin, ceramics, glass, or the like, and is intended for fixing the thermal head 1 and radiating heat.

  The thermal head 1 has a plate shape as shown in FIG. 2A, and as shown in FIG. 2B and FIG. 3 (cross-sectional view taken along the line BB in FIG. 2A), heat dissipation. A rectangular support substrate (substrate) 3 fixed to the plate 15, a heat storage layer 5 bonded to the surface of the support substrate 3, a plurality of heating resistors 7 provided on the heat storage layer 5, and a heating resistor It has electrode portions 8A and 8B connected to the body 7, and a protective film 9 that covers the heating resistor 7 and the electrode portions 8A and 8B and protects them from wear and corrosion. In FIG. 2A, an arrow Y indicates the feeding direction of the thermal paper 12 by the paper feeding mechanism 17.

The support substrate 3 is an insulating substrate such as a glass substrate or a silicon substrate having a thickness of about 300 μm to 1 mm, for example. A rectangular concave portion 2 extending in the longitudinal direction is formed on the surface of the support substrate 3 on the heat storage layer 5 side. The depth of the concave portion 2 is denoted by D.
As shown in FIG. 4 (cross-sectional view taken along the line CC in FIG. 2A), the recess 2 has a columnar protrusion (a restricting portion) 2A that protrudes toward the opening in the vicinity of the approximate center of the bottom surface. Is provided. The tip of the protruding portion 2A is formed in a substantially flat shape.

  The heat storage layer 5 is made of thin glass having a thickness of about 5 to 50 μm. More preferably, the thickness is about 10 μm or less. The heat storage layer 5 and the support substrate 3 are joined by anodic bonding.

  Between the support substrate 3 and the heat storage layer 5, a hollow portion (hereinafter referred to as “hollow heat insulating layer”) 4 is formed by covering the concave portion 2 of the support substrate 3 with the heat storage layer 5. . The hollow heat insulating layer 4 functions as a heat insulating layer that suppresses the inflow of heat from the heat storage layer 5 to the support substrate 3, and has a communication structure that faces all the heating resistors 7. By causing the hollow portion to function as a heat insulating layer, it is possible to suppress the heat generated in the heating resistor 7 from being transmitted to the support substrate 3 via the heat storage layer 5. As a result, the amount of heat conducted to the upper side of the heating resistor 7 and used for printing or the like is increased, so that the heat generation efficiency is improved.

Inside the hollow heat insulating layer 4, a gap G is provided between the tip of the protruding portion 2 </ b> A and the heat storage layer 5. The gap G is the heat storage layer 5 is within the size of the range of possible contact with the tip of the projecting portion 2A in the range of elastic deformation, for example, preferably less than about 0.1 [mu] m greater than or equal to about 1 [mu] m. As a result, as shown in FIG. 5, when the heating resistor 7 is pressurized with a load of a predetermined level or more due to the pressing force of the platen roller 13, the heat storage layer 5 does not break and comes into contact with the protruding portion 2A. Has come to be supported.

  The heating resistors 7 are provided on the upper end surface of the heat storage layer 5 so as to straddle the recesses 2 in the width direction, and are arranged at predetermined intervals in the longitudinal direction of the recesses 2. That is, each heat generating resistor 7 is provided so as to face the hollow heat insulating layer 4 with the heat storage layer 5 interposed therebetween, and is disposed on the hollow heat insulating layer 4.

  The electrode portions 8A and 8B are for generating heat from the heating resistors 7. The common electrodes 8A connected to one end in the direction orthogonal to the arrangement direction of the heating resistors 7 and the other heating resistors 7 are provided. It is comprised from the individual electrode 8B connected to an end. The common electrode 8A is integrally connected to all the heating resistors 7.

  When a voltage is selectively applied to the individual electrode 8B, a current flows through the heating resistor 7 connected to the selected individual electrode 8B and the common electrode 8A opposite to the selected individual electrode 8B so that the heating resistor 7 generates heat. It has become. In this state, the thermal paper 12 is colored and printed by pressing the thermal paper 12 against the surface portion (printing portion) of the protective film 9 covering the heat generating portion of the heat generating resistor 7 by the operation of the pressurizing mechanism 19. It is like that.

  Note that the portion of each heat generating resistor 7 that actually generates heat (hereinafter, the heat generating portion is referred to as “heat generating portion 7A”) is the portion where the electrode portions 8A and 8B do not overlap the heat generating resistor 7, ie, the heat generating resistor. The body 7 is a region between the connection surface of the common electrode 8 </ b> A and the connection surface of the individual electrode 8 </ b> B, and is a portion located almost directly above the hollow heat insulating layer 4.

Hereinafter, a manufacturing method A (hereinafter simply referred to as “manufacturing method A”) of the thermal head 1 configured as described above will be described.
First, as shown in FIG. 6A, the protrusion 2 protrudes from the bottom surface of the recess 2 and the recess 2 toward the opening on the surface of the support substrate 3 so as to face the region where the heating resistor 7 is formed. 2A.

The recess 2 is formed, for example, by subjecting one surface of the support substrate 3 to sand blasting, dry etching, wet etching, laser processing, or the like.
When the support substrate 3 is processed by sandblasting, a surface of the support substrate 3 is coated with a photoresist material, the photoresist material is exposed using a photomask having a predetermined pattern, and the region other than the region where the recess 2 is formed. Solidify the part.

  Thereafter, one surface of the support substrate 3 is washed to remove the unsolidified photoresist material, thereby obtaining an etching mask (not shown) in which an etching window is formed in a region where the recess 2 is formed. In this state, sandblasting is performed on one surface of the support substrate 3 to form a recess 2 having a depth D (recess formation process). For example, the depth D of the recess 2 is preferably 10 μm or more and less than half the thickness of the support substrate 3.

  When processing by etching such as dry etching or wet etching is performed, an etching mask in which an etching window is formed in a region where the concave portion 2 is formed on the surface of the support substrate 3 is formed as in the processing by the sand blasting. In this state, the recess 2 having a depth D is formed by etching one surface of the support substrate 3.

  For this etching process, for example, dry etching such as reactive ion etching (RIE) or plasma etching is used in addition to wet etching using a hydrofluoric acid-based etching solution or the like. As a reference example, when the substrate is single crystal silicon, wet etching is performed using an etching solution such as a tetramethylammonium hydroxide solution, a KOH solution, or a mixed solution of hydrofluoric acid and nitric acid.

  Next, after all of the etching mask is removed from one surface of the support substrate 3, as shown in FIG. 6B, the height of the protruding portion 2A is lowered (gap forming step). As the processing method, for example, polishing is used.

  Subsequently, as shown in FIG. 6C, a heat storage layer 5 is formed by bonding a thin glass sheet having a thickness of 5 μm to 100 μm to one surface of the support substrate 3 on which the recesses 2 are formed by the recess formation process (bonding process). ). The support substrate 3 and the thin glass are bonded with an adhesive. In addition, it is good also as joining by the direct joining by heat sealing | fusion, without using an contact bonding layer.

When the surface of the support substrate 3 is covered with the heat storage layer 5, that is, the opening of the recess 2 is covered with the thin glass, a hollow portion (hollow heat insulating layer) 4 between the support substrate 3 and the heat storage layer 5. Is formed. Since the thickness of the cavity is determined by the depth D of the recess 2, the thickness of the hollow heat insulating layer 4 can be easily controlled.
In addition, a gap G is formed between the protrusion 2 </ b> A and the heat storage layer 5 inside the hollow heat insulating layer 4.

  Here, the thin glass having a thickness of 100 μm or less is difficult to manufacture and handle, and is expensive. Therefore, instead of directly bonding the thin glass sheet directly to the support substrate 3, a thin glass sheet having a thickness that is easy to manufacture and handle is bonded to the support substrate 3 (see FIG. 6C), and then FIG. As shown in d), processing may be added to the thin glass to have a desired thickness by etching or polishing (thinning step). By doing in this way, the very thin thermal storage layer 5 can be formed in one surface of the support substrate 3 easily and cheaply.

  In addition, various etching employ | adopted for formation of the recessed part 2 as mentioned above can be used for the etching of thin glass. In addition, for polishing the thin glass, for example, CMP (chemical mechanical polishing) used for high-precision polishing of a semiconductor wafer or the like can be used.

  Next, as shown in FIGS. 7A to 7C, the heating resistor 7, the common electrode 8A, the individual electrode 8B, and the protective film 9 are sequentially formed on the heat storage layer 5 (heating resistor). Forming process). The heating resistor 7, the common electrode 8A, the individual electrode 8B, and the protective film 9 can be manufactured using a known manufacturing method for a conventional thermal head.

  Specifically, in the heating resistor forming step, a Ta-based or silicide-based heating resistor is formed on the heat storage layer 5 by using a thin film forming method such as sputtering, CVD (chemical vapor deposition), or vapor deposition. A thin film of material is deposited. By forming a thin film of the heating resistor material using a lift-off method, an etching method, or the like, the heating resistor 7 having a desired shape is formed.

  Subsequently, a wiring material such as Al, Al—Si, Au, Ag, Cu, and Pt is formed on the heat storage layer 5 by sputtering or vapor deposition as in the heating resistor forming step. Then, this film is formed by using a lift-off method or an etching method, or the wiring material is screen-printed and then fired to form the common electrode 8A and the individual electrode 8B having desired shapes. The order in which the heating resistor 7, the common electrode 8A, and the individual electrode 8B are formed is arbitrary.

  In patterning the resist material for lift-off or etching in the heating resistor 7 and the electrode portions 8A and 8B, the photoresist material is patterned using a photomask.

After forming the heating resistor 7, the common electrode 8A, and the individual electrode 8B, a protective film material such as SiO ₂ , Ta ₂ O ₅ , SiAlON, Si ₃ N ₄ , diamond-like carbon, etc. is sputtered on the heat storage layer 5 by ion plating. A protective film 9 is formed by filming by CVD, CVD, or the like. Thereby, the thermal head 1 shown in FIG. 1 is manufactured.

Next, the relationship between the load of the platen roller 13 acting on the thermal head 1 in the thermal printer 10 according to the present embodiment and the strength of the heat storage layer 5 with respect to the external load will be described.
A substantially uniform surface load is applied to the surface of the protective film 9 (not shown, hereinafter referred to as “head surface”) on the heat generating resistor 7 in contact with the thermal paper 12 by the pressing force of the platen roller 13. This surface load causes deflection in the heat storage layer 5 on the hollow heat insulating layer 4. The amount of deflection (sinking displacement) of the heat storage layer 5 is maximized near the center of the hollow heat insulating layer 4 when viewed from the protective film 9 side.

  Further, a point load due to fine particles may be applied to the head surface. When the point load is concentrated at one place near the center of the hollow heat insulating layer 4, the deflection of the heat storage layer 5 is further increased, and the tensile stress on the surface of the heat storage layer 5 in this portion becomes very large.

  In a normal printing state, the load applied to the head surface by the platen roller 13 is a surface load, and the amount of deflection of the heat storage layer 5 that supports the heating resistor 7 is relatively small. Therefore, even if some deflection occurs in the heat storage layer 5, the heat storage layer 5 and the protruding portion 2A are not in contact with each other because the gap G is opened, and the thermal head 1 can maintain high heat insulation performance.

  However, when a large load, particularly a point load, is applied to the head surface, a relatively large deflection occurs in the heat storage layer 5. In such a case, the heat storage layer 5 contacts the protrusion 2A within the range of elastic deformation. Thereby, the deflection of the heat storage layer 5 is restricted so that the heat storage layer 5 does not deform beyond the elastic deformation range, that is, the tensile stress does not exceed the breaking stress of the glass, and the heat storage layer 5 is prevented from being damaged. Can do.

  As described above, according to the printer 10 and the thermal head 1 according to the present embodiment, the heat storage layer 5 can be increased by increasing the strength of the heat storage layer 5 with respect to the external load by the protruding portion 2A that limits the deflection of the hollow heat insulating layer 5. 5 can be reduced, and the heat generation efficiency can be improved. Furthermore, the intensity | strength of the thermal storage layer 5 with respect to an external load can be markedly enlarged by making the clearance gap G between 2 A of protrusion parts and the thermal storage layer 5 or less into 1 micrometer. Therefore, sufficient strength can be obtained even with the heat storage layer 5 having a thickness of 10 μm or less. Thereby, improvement in heat generation efficiency and improvement in strength against an external load can be realized.

Moreover, by making the protrusion 2A into a columnar shape, the contact area when the heat storage layer 5 and the protrusion 2A are in contact with each other can be made relatively small, and a decrease in heat generation efficiency can be suppressed.
Moreover, since the heat generation efficiency of the thermal head 1 is high, power consumption during printing on the thermal paper 12 can be reduced. Further, the contact between the thermal paper 12 and the head surface can be improved without the head surface having an extremely concave shape. Therefore, it is possible to perform printing with excellent print quality with less power.

Note that the present embodiment can be modified as follows.
For example, in the present embodiment, one columnar protruding portion 2A is provided inside the hollow heat insulating layer 4, but the thermal head 101 according to the first modification is shown in FIGS. As shown in b), a plurality of protruding portions 102A may be arranged between the heat generating portions 7A.

  By restricting the deflection of the heat storage layer 5 by the plurality of protrusions 102A arranged over a wide range, the strength of the heat storage layer 5 with respect to an external load can be improved. Further, by disposing the protruding portion 102A between the heat generating portions 7A, the heat generation efficiency of the heat generating portions 7A and the heat insulating performance of the hollow heat insulating layer 4 are made uniform as compared with the case where the protrusions 102A are arranged unevenly. be able to.

  Further, as shown in FIGS. 9A to 11, the thermal head 201 according to the second modification has a wall from the bottom surface toward the opening so as to divide the recess 2 in the vicinity of the substantially middle portion in the longitudinal direction. It is good also as providing 202 A of protrusion parts which protrude in a shape. By doing in this way, it becomes possible to enlarge a contact area with the thermal storage layer 5 compared with 2 A of column-shaped protrusion parts, and to limit the deflection | deviation of the thermal storage layer 5 more stably. In addition, what is necessary is just to form the protrusion part 202A so that the hollow heat insulation layer 4 may be obstruct | occluded in the width direction except the clearance gap G between the thermal storage layers 5. FIG.

[Second Embodiment]
Hereinafter, a thermal head 301 according to a second embodiment of the present invention will be described with reference to the drawings.
In the thermal head 301 according to the present embodiment, as shown in FIGS. 12A to 14, the periphery of the recess 2 on the surface of the support substrate 3 (hereinafter referred to as “peripheral portion 302 </ b> B”) has a corner. It differs from the first embodiment in that it has a gentle curved shape.
Hereinafter, in the description of the present embodiment, portions having the same configuration as those of the thermal head 1 according to the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The peripheral edge 302B of the recess 2 is formed in a curved shape that curves in a direction gradually away from the heat storage layer 5 from the surface of the support substrate 3 toward the inside of the recess 2. For example, as shown in FIG. 15, a slight gap is formed between the heat storage layer 5 and the peripheral portion 302B in a state where the heat storage layer 5 is bent and is in contact with the protruding portion 2A.

Hereinafter, a manufacturing method B (hereinafter simply referred to as “manufacturing method B”) of the thermal head 301 configured as described above will be described with reference to FIGS. 16 (a) to 16 (d).
After the recess forming step (see FIG. 16A), as shown in FIG. 16B, the height of the projecting portion 2A is lowered by the gap forming step, and the corners of the periphery of the recess 2 are taken gently. A curved peripheral portion 302B having a curved shape is formed (peripheral portion forming step). As the curved surface processing method, polishing, wet egg, or the like can be used. In addition, since it is the same as that of the said manufacturing method A about a recessed part formation process, a joining process, and a thin plate formation process, description is abbreviate | omitted.

  Further, the width E and the radius of curvature R of the peripheral portion 302B are set so that the heat storage layer 5 does not completely come into surface contact with the peripheral portion 302B when the heat storage layer 5 is bent due to an external load and comes into contact with the protruding portion 2A. It may be set to. For example, the width E of the peripheral edge 302B is preferably about 1 to 10 μm from the original edge of the recess 2 and the curvature radius R is preferably R ≧ E.

  As described above, according to the thermal head 301 according to the present embodiment, when an external load is applied to the heat storage layer 5 and bending occurs, the stress concentration applied to the heat storage layer 5 near the peripheral edge 302B of the recess 2 is reduced. Can be relaxed. Thereby, the intensity | strength of the thermal storage layer 5 with respect to an external load can be raised more, and the failure | damage of the thermal storage layer 5 can be prevented effectively. Note that the shape of the peripheral portion 302B is not limited to a slope having a curvature, and may be a flat slope.

Next, a manufacturing method C for the thermal heads 1, 101, 201, 301 different from the manufacturing method A and the manufacturing method B will be described with reference to FIGS. 17 (a) to 17 (d).
The manufacturing method C is different from the manufacturing methods A and B in that it includes a temporary joining step and a main joining step (joining step) instead of the gap forming step and the joining step. Hereinafter, detailed description of steps common to the manufacturing methods A and B will be omitted.

  First, as shown in FIG. 17A, the recess 2 is formed on the support substrate 3 by the recess forming step. Next, after cleaning the surface of the support substrate 3, as shown in FIG. 17B, a thin glass plate having a thickness of 5 μm to 100 μm is directly bonded to one surface of the support substrate 3 at room temperature without using an adhesive layer. (Temporary joining process). The support substrate 3 is preferably a substrate made of the same material as the thin glass forming the heat storage layer 5 or a glass substrate having similar properties.

  Subsequently, as shown in FIG. 17C, the thin glass and the supporting substrate 3 (glass substrate) are fused by heat treatment, and the heat storage layer 5 is bonded to the surface of the supporting substrate 3 (main bonding step). The heat treatment is performed at a temperature not lower than the glass transition point of the thin glass and the supporting substrate 3 and not higher than the softening point. By carrying out below the softening point, the shape accuracy of the heat storage layer 5 and the support substrate 3 can be maintained.

  In the main joining step, the hollow heat insulating layer 4 is formed, and the height of the protruding portion 2A is lowered by the expansion of the gas confined in the cavity and the softening of the thin glass and the support substrate 3. Thereby, the gap G can be formed between the protruding portion 2 </ b> A and the heat storage layer 5. Further, a gap G is formed, and a curved shape is formed such that a corner of the periphery of the concave portion 2 of the support substrate 3 is removed and gently curved. Thereby, the peripheral part 302B can be formed. In addition, according to this manufacturing method, the front-end | tip part of 2 A of protrusion parts becomes a curved surface shape which protrudes in the thermal storage layer 5 side. Subsequently, as shown in FIG. 17D, a thinning process may be performed.

As described above, in the temporary bonding step and the main bonding step, the gap G is formed between the protruding portion 2A and the heat storage layer 5 when the support substrate 3 and the heat storage layer 5 are thermally fused. A separate process for forming G can be omitted. Therefore, the number of manufacturing steps can be reduced and the manufacture of the thermal heads 1, 101, 201, 301 can be simplified.
Also in the thermal head 201, as shown in FIGS. 18A to 20, the wall-shaped protruding portion 202A and the peripheral portion 302B of the recessed portion 2 can be formed by a simple process by the manufacturing method C. .

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

1 is a schematic configuration diagram of a thermal printer according to a first embodiment of the present invention. (A) is the top view which looked at the thermal head of FIG. 1 from the protective film side, (b) is an AA arrow cross-sectional view (lateral cross-sectional view) of (a). FIG. 3 is a cross-sectional view (vertical cross-sectional view) taken along the line B-B of the thermal head in FIG. It is CC arrow directional cross-sectional view (longitudinal sectional view) of the thermal head of FIG. It is sectional drawing which showed a mode that a load was applied to the thermal head of FIG. (A) is a longitudinal cross-sectional view which shows a recessed part formation process, (b) is a longitudinal cross-sectional view which shows a clearance gap formation process, (c) is a longitudinal cross-sectional view which shows a joining process, (d) is thin plate-ized. It is a longitudinal cross-sectional view which shows a process. (A) is a longitudinal cross-sectional view which shows the heating resistor formation process of the manufacturing method A which concerns on the 1st Embodiment of this invention, (b) is a longitudinal cross-sectional view which shows the process of forming an electrode part, ( (c) is a longitudinal cross-sectional view which shows the process of forming a protective film. (A) is the top view seen from the thermal head protective film side which concerns on the modification 1 of the 1st Embodiment of this invention, (b) is FF arrowhead sectional drawing of (a). (A) is the top view seen from the thermal head protective film side which concerns on the modification 2 of the 1st Embodiment of this invention, (b) is HH arrow sectional drawing of (a). FIG. 10 is a cross-sectional view of the thermal head of FIG. FIG. 10 is a cross-sectional view of the thermal head of FIG. (A) is the top view seen from the thermal head protective film side which concerns on the 2nd Embodiment of this invention, (b) is KK arrow sectional drawing of (a). FIG. 13 is an LL arrow cross-sectional view of the thermal head of FIG. FIG. 13 is a cross-sectional view of the thermal head of FIG. It is sectional drawing which showed a mode that a load was applied to the thermal head of FIG. (A) is a longitudinal cross-sectional view which shows the recessed part formation process of the manufacturing method B which concerns on the 2nd Embodiment of this invention, (b) is a longitudinal cross-sectional view which shows a clearance gap formation process, (c) is a joining process. (D) is a longitudinal cross-sectional view which shows a sheet-thinning process. (A) is a longitudinal cross-sectional view which shows the recessed part formation process of the manufacturing method C, (b) is a longitudinal cross-sectional view which shows a clearance gap formation process, (c) is a longitudinal cross-sectional view which shows a joining process, (d ) Is a longitudinal sectional view showing a thinning step. (A) is the top view seen from the thermal head protective film side which concerns on the 3rd modification manufactured with the manufacturing method C, (b) is OO arrow cross-sectional view of (a). FIG. 19 is a cross-sectional view of the thermal head of FIG. It is QQ arrow sectional drawing of the thermal head of Fig.18 (a).

Explanation of symbols

1, 101, 201, 301 Thermal head 2 Recess 2A, 202A, 302A Protruding part (deflection control part)
3 Support substrate (substrate)
4 Hollow heat insulation layer (cavity)
5 Thermal Storage Layer 7 Heating Resistor 10 Thermal Printer (Printer)

Claims (8)

A substrate having a recess on the surface;
A heat storage layer bonded to the surface of the substrate;
A plurality of heating resistors provided in a region facing the recess of the substrate on the heat storage layer;
The recess has a size such that the plurality of heating resistors face each other;
Deflection of the heat storage layer in contact with the heat storage layer when the heating resistor is pressurized with a load of a predetermined value or more inside a hollow portion formed between the substrate and the heat storage layer by the recess. Thermal head with a deflection limiting part that limits   The deflection limiting portion is formed in a shape projecting from the bottom surface of the cavity toward the heat storage layer, and a gap within a range where the heat storage layer can contact within the range of elastic deformation is formed between the heat storage layer and the heat storage layer. The thermal head according to claim 1. Wherein the gap between the deflection control unit the heat storage layer is about 1μm or less than about 0.1 [mu] m, according to claim 2 the thickness of the heat storage layer for closing the opening of the recess is about 10μm or less Thermal head.   The thermal according to any one of claims 1 to 3, wherein a peripheral edge of the concave portion on the surface of the substrate has a curved shape that curves in a direction gradually separating from the heat storage layer toward the inside of the concave portion. head. The thermal head according to any one of claims 1 to 4,
A printer comprising: a pressurizing mechanism that presses an object to be printed against the heating resistor of the thermal head. On the surface of the substrate, have a protrusion on the bottom surface, a concave portion forming step of forming a recess sized to oppose the plurality of heating resistors,
A bonding step in which a heat storage layer is thermally fused to the surface of the substrate on which the recess has been formed by the recess forming step;
A heating resistor forming step of forming a plurality of heating resistors facing the recesses on the heat storage layer;
In the thermal head in which the joining step forms a gap between the protruding portion and the heat storage layer using expansion of gas in the recess and softening of the substrate and the heat storage layer at the time of the heat fusion. Production method.   The method for manufacturing a thermal head according to claim 6, wherein the joining step forms the gap so that the heat storage layer contacts the protruding portion within a range of elastic deformation of the heat storage layer.   The thermal bonding according to claim 6 or 7, wherein the bonding step forms a curved surface shape that curves in a direction gradually separating from the heat storage layer toward the inside of the concave portion around the concave portion on the surface of the substrate. Manufacturing method of the head.

Images