JP2008001062A - Thermal print head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal print head which can be easily reduced in size and can increase a printing speed and attain a higher image quality. <P>SOLUTION: A resistor substrate part 12A and a drive circuit substrate part 12B are provided on a heat dissipation substrate 11 to form a heating resistor layer 16 covering a protruding glaze layer 15 on a support substrate 14. A gap G is provided on the heating resistor layer 16 on one slope surface 15b of the glaze layer 15 to form a first electrode 17a and a second electrode 17b, using the gap G portion as a heating part 18. A protective film 19 to overlie the glaze layer 15 and the support substrate 14 are formed to form a heat dissipation layer 20 via the protective film 19 on the other slope surface 15c located opposite to the one slope surface 15b, holding the head top part 15a of the glaze layer 15 in between. The heat dissipation layer 20 dissipates the heat of the heating part 18. In this case, a driver IC 22 on a driving circuit substrate 21 is electrically connected to the electrodes by a bonding wire W, which are all tightly sealed by a sealing material 23. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thermal print head in which a convex glaze layer whose cross-sectional shape in one direction swells in, for example, a mountain shape extends on one principal surface of a substrate, and the head dimensions can be easily reduced.

  A thermal print head is an output device that forms an image composed of characters on a recording medium such as a thermal recording paper or a thermal transfer ink ribbon by using heat generated by a heat generating portion. It is widely used in recording devices such as barcode printers, weighing machines, digital plate-making machines, video printers, imagers, and seal printers. Generally, a thermal print head has a structure in which a resistor substrate portion provided with a heat generating portion for image formation and a drive circuit substrate portion mounted with a drive IC are arranged on one main surface of a heat dissipation substrate. Yes.

  Such a head includes a thermal print head having a convex glaze layer and a thermal print of a flat glaze layer, depending on a method of forming a heat generating portion that generates heat when energized. Here, the thermal print head of the convex glaze layer is usually a convex shape extending and arranged along the direction (main scanning direction) perpendicular to the direction (sub-scanning direction) in which the recording medium is conveyed on the head. Has a glaze layer. Then, a heating element array having a heating portion on the protruding glaze protrusion or one inclined surface thereof is formed. FIG. 5 is a sectional view in the sub-scanning direction, which is one direction, showing an example of this configuration.

  As shown in FIG. 5, in the thermal print head, for example, a resistor substrate portion 102A and a drive circuit substrate portion 102B are provided adjacent to each other on the main surface of the heat dissipation substrate 101. In the resistor substrate section 102 </ b> A, the support substrate 104 is attached to the main surface of the heat dissipation substrate 101 via the adhesive layer 103. A convex glaze layer 105 is formed on the support substrate 104, and the heating resistor layer 106 is formed so as to cover the surface of the convex glaze layer 105 and the surface of the support substrate 104. On the heating resistor layer 106, the first electrode 107a and the second electrode 107b are arranged to face each other with the gap G interposed therebetween. Here, the pair of electrodes 107 including the first electrode 107a and the second electrode 107b are electrically connected to the heating resistor layer 106 in an overlapping manner, and the heating resistor layer 106 exposed in the gap G is formed in the heating part. 108.

  As shown in FIG. 5, the heat generating portion 108 is formed in a region of one slope of the convex glaze layer 105. Then, the pair of electrodes 107 and the heat generating portion 108 which are energization electrodes of the heat generating portion 108 become one heat generating element, and are arranged in a line as a predetermined number, for example, 2056 heat generating element arrays in the main scanning direction of the thermal print head. . Further, the edge portions of the pair of electrodes 107 are exposed and are entirely covered with a protective film 109 for bonding wire connection described later.

  On the other hand, the drive circuit board portion 12B is composed of a drive circuit board 110 or the like adhered to the heat dissipation board 101 via an adhesive layer 103, and a circuit pattern (not shown) or the like is formed on the substrate surface. Is installed. Then, the bonding electrodes W are electrically connected between the energization electrode of the resistor substrate portion 12A and the drive IC 111 of the drive circuit substrate portion 12B and between the drive IC 111 and the circuit pattern of the drive circuit substrate 12B. Has been. These bonding wires W and driving ICs 111 are hermetically sealed with a sealing material 112 made of, for example, an epoxy resin.

  In forming an image on a recording medium using the thermal print head, a thermal recording paper, a thermal transfer ink ribbon, or the like (not shown) is interposed between the protective film 109 and the platen roller 113 in one inclined area of the convex glaze layer 105. And are conveyed at a predetermined speed in the sub-scanning direction. In this conveyance, the heat-sensitive recording medium is heated by the heat generating portion 108 disposed in the one slope area, and the recording medium is printed by the heat.

  Thus, the thermal print head having the convex glaze layer forms a convex glaze layer 105 whose cross-sectional shape in the sub-scanning direction on the support substrate 104 is raised to a convex shape having a mountain shape or a trapezoidal shape. The heat generating part 108 is provided on the surface, and the convex glaze layer 105 is raised in the above mountain shape, thereby improving the adhesion of the heat-sensitive recording paper, the thermal transfer ink ribbon, etc. to the heat generating part 108 and the heat generating part 108. Therefore, it is possible to improve the heat storage property and to easily reduce the power consumption. In addition, the size of the support substrate 104 in the sub-scanning direction can be easily reduced.

However, the convex glaze type thermal print head has a problem that it is difficult to achieve high speed and high image quality in a recording apparatus equipped with the same. In the above speeding up, it is essential to shorten the non-printing time as well as the printing time on the recording medium. Here, since the thermal conductivity of the convex glaze layer 105 of the convex glaze type described above is low, the heat storage property of the heat generating part 108 provided on the upper part is generally higher than that of the thin film thermal print head. When this heat storage property is high, the time required for printing the heat generating portion 108 is shortened, and the printing time can be shortened. However, if the non-printing time is shortened, sufficient heat dissipation of the heat generating portion 108 provided on the convex glaze layer 105 cannot be ensured. Even if the protective layer is selected as a material having better thermal conductivity than the glaze layer, the protective layer is thin and does not contribute to sufficient heat dissipation. If this heat radiation cannot be sufficiently performed, the cut of the printing point is deteriorated, and blurring of image quality in the sub-scanning direction becomes obvious and can be visually recognized.
As described above, the conventional convex glaze type thermal print head has a structure that is suitable for downsizing of the head size but is difficult to achieve both high speed and high image quality as compared with the thin film type thermal print head. .

  As a means for ensuring the heat radiation, there is adjustment of the driving conditions of the thermal print head. For example, in consideration of heat radiation to the recording medium of the heat generating unit 108 at the time of printing, the heat generation time is shortened and adjusted so that the optimum printing is performed in image formation of an actual recording device. However, with this method, if the increase in speed becomes significant, it becomes impossible to cope with it sufficiently. For this reason, in the above-described convex glaze type thermal print head, a novel head structure that can stably control the heat storage and heat dissipation of the heat generating portion without hindering the reduction of the size of the head in the sub-scanning direction is required. It has become.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a convex glaze type thermal print head in which the head size can be easily reduced, and the speed and image quality can be increased. And

  In order to achieve the above object, a thermal printhead according to the present invention includes a convex glaze layer in which a cross-sectional shape in one direction protrudes from a support rib in a principal surface of a support substrate, and the convex glaze layer. A heating resistor layer formed on a surface portion of the support substrate, an electrode formed by providing a gap on the heating resistor layer on one slope of the convex glaze layer, and exposed in a gap portion of the electrode A surface that covers at least the heat generating portion of the heat generating resistor layer, is laminated on the convex glaze layer and the support substrate, and a surface that continues to the one slope with the top of the convex glaze layer interposed therebetween, for example, opposite A heat-dissipating layer that covers the other slope located on the side through the protective film, and the heat-dissipating layer is configured to dissipate heat generated by the heat-generating unit.

  Alternatively, the thermal print head according to the present invention includes a resistor substrate portion and a drive circuit substrate portion provided on one main surface of the heat dissipation substrate, and the resistor substrate portion is positioned above the heat dissipation substrate. A convex glaze layer whose cross-sectional shape in one direction projects in a mountain shape, a heating resistor layer formed on the convex glaze layer, and a gap on the heating resistor layer on one slope of the convex glaze layer An electrode formed and a protective film that covers at least the heating portion of the heating resistor layer exposed in the gap portion of the electrode and is laminated on the convex glaze layer, and the drive circuit board portion includes: In a thermal print head having a drive IC that is positioned above the heat dissipation substrate and controls a current that flows to the heat generating portion, a sealing material that seals the drive IC is sandwiched between the top of the convex glaze layer. On the other side of the slope On other slopes that location covered through the protective film has a structure that dissipates heat generated by the heat generating portion.

  With the configuration of the present invention, it is possible to provide a thermal print head in which the head size can be easily reduced, and the speed and image quality can be increased.

Several preferred embodiments of the present invention will be described below with reference to the drawings. Hereinafter, the same or similar parts are denoted by common reference numerals, and redundant description is omitted. However, the drawings are schematic and ratios of dimensions and the like are different from actual ones.
(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is a top view showing a thermal print head according to a preferred embodiment. FIG. 2 is an enlarged cross-sectional view taken along arrow XX in FIG.

As shown in FIGS. 1 and 2, in the thermal print head 10, a resistor substrate portion 12 </ b> A and a drive circuit substrate portion 12 </ b> B are provided adjacent to each other on the main surface of the heat dissipation substrate 11. In this resistor substrate portion 12A, a support substrate 14 having good heat resistance and heat conductivity such as Al ₂ O ₃ (alumina) is stuck on the main surface of the heat dissipation substrate 11 via an adhesive layer 13. Yes. A convex glaze layer 15 having a mountain-shaped cross-sectional shape in the sub-scanning direction, which is one direction, is disposed in the main scanning direction along the edge portion on the support substrate 14, and the surface of the convex glaze layer 15 and the support are supported. A heating resistor layer 16 is formed covering the surface of the substrate 14.

  Then, as described in the prior art, the first electrode 17a and the second electrode 17b, which are overlapped and electrically connected to the heating resistor layer 16, are arranged to face each other with the gap G interposed therebetween. The heating resistor layer 16 exposed in the gap G becomes the heating portion 18. In this way, the heat generating portion 18 is formed on one inclined surface 15b with the top portion (intermediate portion) 15a of the convex glaze layer 15 having a cross-sectional shape raised in a convex shape having a mountain shape as a boundary. A pair of electrodes 17 consisting of the first electrode 17a and the second electrode 17b and the heat generating portion 18 are used as one heat generating element, and a predetermined number, for example, 2056 heat element arrays are arranged in a row in the main scanning direction of the thermal print head. Placed in.

  And the edge part of a pair of electrode 17 is exposed for the bonding wire connection mentioned later, and the whole is coat | covered with the protective film 19 with good heat conductivity. Further, the heat radiation layer 20 covers this protective film 19, and another slope located on the opposite side of the top of the mountain shape with respect to one slope where the heat generating portions 18 of the convex glaze layer 15 are arranged. It is arranged along the main scanning direction on the support substrate 14 so as to cover it.

  The drive circuit board portion 12B has a drive circuit board 21 attached to the heat dissipation board 11 via the adhesive layer 13 in the same manner as described in the prior art, and a circuit pattern or the like is formed on the substrate surface. A drive IC 22 and the like are mounted. The driving IC 22 and the pair of electrodes 17 and the circuit pattern are electrically connected by a bonding wire W, and the bonding wire W and the driving IC 22 are hermetically sealed by a sealing material 23 made of, for example, an epoxy resin. .

  As described above, the thermal print head 10 includes the convex glaze layer 15 in which the heat generating portion 18 of the heat generating element is near the end of the resistor substrate portion 12A and the cross-sectional shape in one direction of the support substrate 14 is raised in a mountain shape. A so-called near-edge structure is formed, which is formed on one slope and the drive IC 22 is disposed on the opposite side across the top of the glaze layer. In the near-edge structure thermal print head 10, the heat radiation layer 20 is provided between the convex glaze layer 15 and the sealing material 23 raised in two convex shapes and covers the other slope of the convex glaze layer 15. Formed. With such a structure, the heat dissipation layer 20 does not come into contact with the recording medium being conveyed.

  In the thermal print head 10, the heat dissipation substrate 11 is made of, for example, Al (aluminum) metal, and the adhesive layer 13 is made of an adhesive made of resin such as double-sided tape or silicone having good thermal conductivity. The ceramic support substrate 14 is usually a support substrate made of an insulating material having heat resistance, and may be made of silicon, quartz, silicon carbide or the like in addition to alumina ceramics.

  The convex glaze layer 15 may be any insulator material that has an action of accumulating and dissipating the heat generated by the heat generating portion 18 and having surface smoothness. For example, it is made of a glass film made of silicon oxide, or a low thermal conductive material such as polyimide resin.

  The heating resistor layer 16 is made of, for example, a TaSiO, NbSiO, TaSiNO, or TiSiCO based electric resistor material. An electrode such as a pair of electrodes that are composed of the first electrode 17a and the second electrode 17b and that serves as a current-carrying electrode is preferably as low as possible. For example, a metal such as Al, Cu (copper), or an AlCu alloy is mainly used. Composed of materials.

The protective film 19 is made of a hard and dense insulating material such as Si ₃ N ₄ (silicon nitride), SiON (silicon oxynitride) or SiC (silicon carbide). Here, it is preferable that at least Si (silicon) and carbon (C) are contained in the outermost surface of the protective film 19 because the thermal conductivity becomes high. This protective film 19 covers the pair of electrodes 17 and the heat generating portion 18 of the heat generating element array, and has a function of protecting the recording medium from abrasion due to pressure contact or sliding contact, and corrosion due to contact with moisture contained in the atmosphere. Have.

  The heat dissipation layer 20 is formed of a conductive material or an insulating material having a higher thermal conductivity than the glaze layer as a heat sink. Here, examples of the conductor material include metal materials such as Al and Cu, refractory metals, and nitrides of refractory metals. Among these, TiN (titanium nitride), TaN (tantalum nitride), WN (tungsten nitride), MoN (molybdenum nitride), and the like, which are nitrides of high-melting point metals with high wear resistance, are suitable. As the insulator material, AlN (aluminum nitride) is suitable.

Next, a method for manufacturing the thermal print head 10 will be described. First, an elongated support substrate 13 made of alumina and having a width of about 3 mm in the sub-scanning direction and a thickness of 0.5 mm to 1 mm is prepared. Then, in the vicinity of the edge of the surface, along the main scanning direction, for example, a glass paste obtained by adding and mixing a suitable organic solvent and solvent to SiO ₂ (silicon oxide) glass powder is applied by a well-known screen printing method. Form. Thereafter, firing is performed at a predetermined temperature, and the convex glaze layer 15 whose cross-sectional shape is mountain-shaped and whose top height is, for example, 10 μm to 100 μm and whose width in the sub-scanning direction is, for example, 100 μm to 500 μm is formed on the surface of the support substrate 14 Adhere to. In addition, the convex glaze layer 15 may be a polyimide resin or the like.

Next, a TaSiO ₂ film having a thickness of about 0.05 μm is formed on the surface of the convex glaze layer 15 and the surface of the support substrate 14 by, for example, sputtering, and the heating resistor layer 16 is formed by a photoengraving process. To do. Subsequently, the heating resistor layer 16 is coated by sputtering to form an Al film or an AlCu alloy film having a thickness of, for example, about 0.5 μm, and the energization electrodes of the heating element array are formed by a photoengraving process. The first electrode 17a and the second electrode 17b are formed by patterning. Here, the heating resistor layer 16 and the energization electrode may be formed in the same pattern by a single photoengraving process.

Thereafter, a protective film 19 that covers the entire surface is formed by sputtering. Here, the protective film 19 is made of, for example, a Si ₃ N ₄ film or a SiC film having a high thermal conductivity with a film thickness of about 2 μm to 5 μm.

  A TiN film having a thickness of 0.5 μm to 1 μm and a width of 0.5 mm to 1 mm, for example, is mainly formed between the convex glaze layer 15 and the sealing material 23 by a sputtering method using a film formation mask which is a shadow mask. The heat dissipation layer 20 is formed along the scanning direction. Here, the heat dissipation layer 20 is disposed so as to cover the other slope located on the opposite side of the top of the slope where the heat generating portions 18 of the convex glaze layer 15 are arranged.

  Next, the resistor substrate portion 12A and the drive circuit substrate portion 12B in which, for example, a bare chip drive IC 22 is incorporated in advance are placed and fixed on the heat dissipation substrate 11 made of an aluminum plate or the like via an adhesive. Then, all the energization electrodes of the heating element array are electrically connected to the bonding pads on the output side of the drive IC 22 by bonding wires W made of, for example, Al wires or Au wires. Further, the bonding pad on the input side of the driving IC 22 is electrically connected to the circuit pattern of the driving circuit board 21 by the bonding wire W. Finally, the driving IC 22 and the bonding wire W are hermetically sealed with the sealing material 23 by a known mounting technique. Thus, the thermal print head 10 of this embodiment is completed.

  The thermal print head 10 of the present embodiment has a near edge structure in which a heat generating portion 18 of the heat generating element array is formed on one slope of the convex glaze layer 15. The heat radiation layer 20 is disposed in the main scanning direction via the protective film 19 on the other slope 15c located on the opposite side of the top 15a with respect to the slope 15b of the convex glaze layer 15 and the support substrate 14. Has been. For this reason, the heat generated by the heat generating portion 18 is transferred through the heat-conductive protective film 19 and absorbed by the nearby heat dissipation layer 20. The absorbed heat is diffused throughout the heat dissipation layer 20 and is also radiated or convectively dissipated into the atmosphere in contact with the surface of the heat dissipation layer 20. In this way, the heat generated in the heating element array can be easily dissipated through the heat dissipation layer 20.

  In addition, it is possible to achieve high speed and high image quality in a recording device including the thermal print head of the present embodiment. Further, since the convex glaze type thermal print head is used, it is easy to reduce the size of the support substrate 14 in the sub-scanning direction, and it is possible to reduce the substrate cost and the size of the thermal print head. Further, since the heat dissipation layer 20 is disposed on the opposite side across the top of the convex glaze layer 15 having a near edge structure, the heat dissipation layer 20 does not slidably contact the recording medium to be conveyed. Will not wear out.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. 3 and FIG. A feature of the present embodiment is that the sealing material 23 with enhanced thermal conductivity has the function of the heat dissipation layer 20 of the first embodiment, and the dimension of the support substrate 14 in the thermal print head in the sub-scanning direction is further increased. It is in place to be able to reduce. Here, FIG. 3 is a top view showing a thermal print head according to a preferred embodiment. FIG. 4 is an enlarged cross-sectional view taken along arrow YY in FIG.

  As shown in FIGS. 3 and 4, in the thermal print head 10a, the resistor substrate portion 12A and the drive circuit substrate portion 12B are provided on the main surface of the heat dissipation substrate 11, as described in the first embodiment. . In the resistor substrate portion 12A, a ceramic support substrate 14 having a width in the sub-scanning direction of about 2 mm and a plate thickness of about 0.5 mm is attached to the main surface of the heat dissipation substrate 11 via the adhesive layer 13. . The convex glaze layer 15 is arranged in the main scanning direction along the edge portion on the support substrate 14 so as to have a near edge structure, and covers the surface of the convex glaze layer 15 and the surface of the support substrate 14 to generate a heating resistor. A body layer 16 is formed.

  Then, as described in the first embodiment, the first electrode 17a and the second electrode 17b that are overlapped and electrically connected to the heating resistor layer 16 are arranged to face each other with the gap G interposed therebetween. In this way, the heating resistor layer 16 exposed to the gap G formed on one slope of the convex glaze layer 15 whose cross-sectional shape is raised in a convex shape with a mountain shape becomes the heating portion 18. Then, a predetermined number, for example, 2056 heating element arrays are arranged in a row in the main scanning direction of the thermal print head, with the pair of electrodes 17 and the heating portion 18 as the energization electrodes as one heating element.

  In this way, the edge portions of the pair of electrodes 17 are exposed and the whole is covered with the protective film 19 having good thermal conductivity for bonding wire connection described later.

  The drive circuit board portion 12B has a drive circuit board 21 attached to the heat dissipation board 11 via the adhesive layer 13 in the same manner as described in the prior art, and a circuit pattern or the like is formed on the substrate surface. A drive IC 22 and the like are mounted. The drive IC 22 and the pair of electrodes 17 and the circuit pattern are electrically connected by a bonding wire W.

  As a characteristic matter of the present embodiment, the heat radiation sealing material 23a covers the protective film 19, and sandwiches the top of the head with respect to one slope on which the heat generating portions 18 of the convex glaze layer 15 are arranged. It is formed along the main scanning direction on the support substrate 14 so as to cover the other slope 15c located on the opposite side. Here, the heat radiation sealing material 23 a hermetically seals the bonding wire W and the drive IC 22. Thus, the heat dissipation sealing material 23a has a function of radiating heat generated from the heating element array together with a sealing function of original mounting.

Examples of such a heat radiation sealing material 23a include those in which a filler having high thermal conductivity is mixed in a normal sealing resin. As the filler having high thermal conductivity, for example, a ceramic fine particle such as Al ₂ O ₃ , AlN, SiC, Si ₃ N ₄ is suitable. Here, the particle diameter of the fine particles is preferably 10 μm to 100 μm, and the content thereof is determined by the kind of fine particles to be mixed or the heat radiation amount. % To 90 vol. % Is appropriately set.

  By mixing a filler having a high thermal conductivity in the sealing resin, the thermal conductivity becomes approximately the same as the thermal conductivity of the ceramic. For example, an epoxy resin having a normal thermal conductivity of a little less than 0.2 W / m · K is, for example, 80 vol. By being contained in about%, the heat radiation sealing material 23a having a thermal conductivity of about 20 W / m · K is obtained. Here, in the case of the heat radiation sealing material 23a in which a filler made of aluminum nitride fine particles is mixed instead of alumina fine particles, the thermal conductivity is about 100 W / m · K, which is described in the first embodiment. It becomes the same level as the heat dissipation layer 20.

  The thermal print head 10a according to the second embodiment enables high speed and high image quality in the recording device due to the same heat dissipation effect as the heat dissipation layer 20 in the first embodiment. Further, the separation distance between the convex glaze layer 15 and the sealing material 23a on the heat dissipation substrate 11 can be reduced very easily. For this reason, the sub-scanning of the support substrate 14 is further performed than in the case of the first embodiment. The direction dimension can be reduced, and the substrate cost can be further reduced and the thermal print head can be downsized.

  Although the preferred embodiments of the present invention have been described above, the above-described embodiments do not limit the present invention. Those skilled in the art can make various modifications and changes in specific embodiments without departing from the technical idea and technical scope of the present invention.

  For example, the drive circuit board portion 12B may be formed on the same support substrate 14 as the resistor substrate portion 12A. In the first embodiment, the drive circuit board portion 12B may be arranged at a location different from the thermal print head. For example, it may be attached to a control device of a recording device, and for example, the output of the drive IC 22 may be transmitted to the resistor substrate portion A through the circuit wiring of the flexible wiring board.

Further, the support substrate 14 and the drive circuit substrate 21 may be attached to the heat dissipation substrate using different adhesives. This is preferable for preventing breakage due to cracks when the support substrate 14 and the drive circuit substrate 21 have different thermal expansion coefficients.
Further, the cross-sectional shape of the convex glaze layer may be a triangular base having a slope with respect to the support collar on the surface on which the platen abuts.
Further, the heat radiation area can be increased by providing irregularities on the surface of the heat radiation layer.

1 is a schematic top view showing a thermal print head according to a first embodiment of the present invention. The expanded cross-sectional view of the XX arrow of FIG. The typical top view showing the thermal print head concerning a 2nd embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view taken along arrow YY in FIG. Sectional drawing which shows the thermal print head concerning the prior art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 10a ... Thermal print head, 11 ... Radiation board, 12A ... Resistor board part, 12B ... Drive circuit board part, 13 ... Adhesive layer, 14 ... Supporting board, 15 ... Convex glaze layer, 16 ... Heating resistor layer , 17a ... first electrode, 17b ... second electrode, 18 ... heat generating part, 19 ... protective film, 20 ... heat dissipation layer, 21 ... drive circuit board, 22 ... drive IC, 23 ... sealing material, 23a ... heat dissipation Sealing material, 24 ... radiating filler, G ... gap, W ... bonding wire

Claims (5)

A convex glaze layer in which a cross-sectional shape in one direction projects from the support substrate in a convex shape on one main surface of the support substrate;
A heating resistor layer formed on the surface portion of the support substrate including the convex glaze layer;
An electrode formed with a gap on the heating resistor layer on one slope of the convex glaze layer;
A protective film that covers at least the heat generating portion of the heating resistor layer exposed in the gap portion of the electrode and is laminated on the convex glaze layer and the support substrate;
A heat-dissipating layer that covers the surface following the one slope across the top of the convex glaze layer via the protective film, and
The thermal print head according to claim 1, wherein the heat dissipation layer dissipates heat generated by the heat generating portion.   The thermal print head according to claim 1, wherein the heat dissipation layer is made of a conductive material. A resistor substrate portion and a drive circuit substrate portion provided on one main surface of the heat dissipation substrate are provided, and the resistor substrate portion is located above the heat dissipation substrate and protrudes in a mountain shape in one direction. A convex glaze layer, a heating resistor layer formed on the convex glaze layer, an electrode formed with a gap on the heating resistor layer on one slope of the convex glaze layer, and a gap between the electrodes A protective film that covers at least the heat generating portion of the heat generating resistor layer exposed to the portion and is laminated on the convex glaze layer, and the drive circuit board portion is located above the heat dissipation substrate and the heat generating portion. In a thermal print head having a driving IC for controlling a current flowing through
A sealing material that seals the driving IC covers the other slope on the opposite side of the one slope across the top of the convex glaze layer via the protective film, and emits the heat generating part. A thermal print head that dissipates heat.   4. The thermal print head according to claim 3, wherein the sealing material is made of a resin containing a heat dissipating filler. The thermal print head according to any one of claims 1 to 4, wherein the outermost surface of the protective film contains at least silicon and carbon.

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