JP5441665B2 - RECORDING HEAD AND RECORDING DEVICE HAVING THE SAME - Google Patents

Description

  The present invention relates to a recording head and a recording apparatus including the recording head.

  Conventionally, various recording heads such as thermal heads have been proposed as printing devices such as facsimiles and video printers. For example, in the thermal head (thermal print head) described in Patent Document 1, a support substrate in which a plurality of heat generating elements (heat generating portions) are arranged in a row on an upper surface is disposed on a heat radiating plate via a heat radiating adhesive. ing. And the inside of the layer which consists of this heat dissipation adhesive contains the powder which consists of alumina ceramics etc. which have a particle size substantially the same as the thickness of this layer.

JP 2008-201013 A

  In the thermal head described in Patent Document 1, since a plurality of heating elements are arranged in a row, the heating element arranged at the center is more preferable than the heating elements arranged at both ends in the arrangement direction of the heating elements. , Tend to be stored easily.

  However, in the thermal head described in Patent Document 1, since the heat dissipation plate and the support substrate are joined with a heat dissipation adhesive containing powder having substantially the same particle size, the distance between the heat dissipation plate and the support substrate is It is constant at the center and both ends in the arrangement direction of the heating elements. Therefore, the heat radiation characteristics are substantially the same at the center and both ends of the support substrate in the arrangement direction of the heat generating elements.

  For this reason, there is a problem that a temperature difference occurs between the heating element arranged at the center and the heating elements arranged at both ends, and the print density in the arrangement direction of the heating elements becomes uneven.

  SUMMARY An advantage of some aspects of the invention is that it provides a recording head that can suppress unevenness in print density in the arrangement direction of heating elements, and a recording apparatus including the recording head.

  The recording head of the present invention has a heat radiator, a head base disposed on the heat sink and having a heat generating element array on which a plurality of heat generating elements are arranged on the upper surface, and the heat generating element array on the lower surface of the head base. A first bonding layer that is interposed between the first region directly below and the heat dissipating member, extends in the arrangement direction of the heat generating elements, and joins the first region and the heat dissipating member, and a lower surface of the head substrate. And a second bonding layer that is interposed between the second region other than the first region and the heat dissipating member, extends in the arrangement direction of the heat generating elements, and joins the second region and the heat dissipating member. At least one of the first bonding layer and the second bonding layer is a particle-containing layer that internally contains a plurality of spacer particles that are in contact with both the lower surface of the head substrate and the radiator. The spacer particles Thermal conductivity, characterized in that higher in the arranged spacer particles in the center portion than the spacer particles disposed at both ends of the particle-containing layer in the direction of arrangement of the heating elements.

  In the recording head of the present invention, the spacer particles may have higher thermal conductivity as the spacer particles are arranged closer to the center of the particle-containing layer in the arrangement direction of the heating elements.

  Further, the contact area with the spacer particles per unit area in the bonding region with the particle-containing layer on the lower surface of the head substrate may be larger in the center than at both ends in the arrangement direction of the heating elements. .

  Further, the plurality of spacer particles have a spherical shape having the same particle diameter, and the density of the spacer particles arranged in the particle-containing layer is equal to both end portions of the particle-containing layer in the arrangement direction of the heating elements. It may be higher at the center.

  The spacer particles may be arranged at both ends of the particle-containing layer in the arrangement direction of the heating elements, with the spacer particles arranged at the center of the particle-containing layer in the arrangement direction of the heating elements. It may be smaller than the spacer particles formed.

  In the recording head of the present invention, the upper surface of the heat dissipating member may protrude toward the head substrate at the center portion from both end portions in the arrangement direction of the heat generating elements.

  Further, the upper surface of the head substrate may protrude at the center portion from both end portions in the arrangement direction of the heat generating elements.

  The first bonding layer may be made of an adhesive. The second bonding layer may be composed of a double-sided tape.

  Further, the recording apparatus of the present invention includes the recording head configured as described above, and a platen roller that presses a recording medium onto the heating element of the head base, and the platen roller includes an array of the heating elements. Both ends in the direction are rotatably supported.

  ADVANTAGE OF THE INVENTION According to this invention, the recording head which can suppress the nonuniformity of the printing density in the sequence direction of a heat generating element, and a recording apparatus provided with the same can be provided.

(A) is a top view which shows schematic structure of the thermal head which is one Embodiment of the recording head of this invention. (B) is a side view of the thermal head shown in (a). (A) is the top view to which the principal part of the thermal head shown in FIG. 1 was expanded. (B) is IIb-IIb sectional drawing of the thermal head shown to (a). It is a disassembled perspective view which shows schematic structure of the wiring member shown in FIG. It is a schematic block diagram which shows the joining state of the head base | substrate and heat radiator shown in FIG. In addition, (a) is the top view which abbreviate | omitted illustration of the head base | substrate. (B) is IVb-IVb sectional drawing of (a), (c) is IVc-IVc sectional drawing of (a). 1 is a diagram illustrating a schematic configuration of a thermal printer that is an embodiment of a recording apparatus of the present invention. FIG. (A) is a top view which shows with a schematic structure the modification of the joining state of the head base | substrate and heat radiator shown in FIG. (B) is VIb-VIb sectional drawing of (a), (c) is VIc-VIc sectional drawing of (a). (A) is a top view which shows with a schematic structure the modification of the joining state of the head base | substrate and heat radiator shown in FIG. (B) is VIIb-VIIb sectional drawing of (a), (c) is VIIc-VIIc sectional drawing of (a). (A) is a top view which shows with a schematic structure the modification of the joining state of the head base | substrate and heat radiator shown in FIG. (B) is VIIIb-VIIIb sectional drawing of (a), (c) is VIIIc-VIIIc sectional drawing of (a). (A) is a top view which shows with a schematic structure the modification of the joining state of the head base | substrate and heat radiator shown in FIG. (B) is IXb-IXb sectional drawing of (a), (c) is IXc-IXc sectional drawing of (a). (A) is a top view which shows with a schematic structure the modification of the joining state of the head base | substrate and heat radiator shown in FIG. (B) is Xb-Xb sectional drawing of (a), (c) is Xc-Xc sectional drawing of (a). (A) is a top view which shows with a schematic structure the modification of the joining state of the head base | substrate and heat radiator shown in FIG. (B) is XIb-XIb sectional drawing of (a), (c) is XIc-XIc sectional drawing of (a).

  Hereinafter, a thermal head which is an embodiment of a recording head of the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the thermal head X of the present embodiment includes a head substrate 10, a drive IC 20, a wiring member 30, and a radiator 40. For convenience of explanation, in FIG. 2A, illustration of the drive IC 20, the wiring member 30, the heat radiating body 40, and a protective layer 15 described later is omitted, and in FIG. 2B, illustration of the heat radiating body 40 is omitted. ing.

  The head base 10 includes a head substrate 11, a glaze layer 12, an electric resistance layer 13, and an electrode wiring 14 formed in order on the head substrate 11. Further, the glaze layer 12 has a flat base portion 12a and a protruding portion 12b protruding from the upper surface of the base portion 12a. In the region of the electrical resistance layer 13 located on the top of the protruding portion 12b of the glaze layer 12, the electrode wiring 14 is not formed on the upper surface, and this region constitutes the heating element 13a. A protective layer 15 is formed on the upper surface of the heat generating element 13a and a part of the upper surface of the electrode wiring 14.

  The head substrate 11 has a function of supporting the glaze layer 12, the electrical resistance layer 13, the electrode wiring 14, the protective layer 15, and the drive IC 20. The head substrate 11 is configured in a rectangular shape extending in the direction of the arrow D1-D2 in plan view, and the main surface is rectangular. Examples of the material for forming the head substrate 11 include insulating materials. For example, ceramics such as alumina ceramics and inorganic materials such as glass materials are preferably used.

  On the upper surface of the head substrate 11, the glaze layer 12 is entirely formed because the patterning of the electric resistance layer 13 and the electrode wiring 14 by photolithography becomes easy and the smoothness can be improved and the manufacture is easy. Are provided.

  The glaze layer 12 has a function of temporarily storing a part of heat generated in a heating element 13a described later of the electrical resistance layer 13. That is, the glaze layer 12 plays a role of improving the thermal response characteristics of the thermal head X by shortening the time required to raise the temperature of the heating element 13a. An example of a material for forming the glaze layer 12 is glass.

  The base 12a of the glaze layer 12 is provided in a substantially flat shape over the entire upper surface of the head substrate 11, and the thickness thereof is 20 to 250 μm. The protruding part 12b of the glaze layer 12 is a part that contributes to pressing the recording medium against the protective layer 15 located on the heating element 13a. The protrusion 12b protrudes upward (D5 direction) from the base 12a. Further, the protruding portion 12b is formed in a strip shape extending in the main scanning direction (D1-D2 direction). The protrusion 12b has a substantially semi-elliptical cross-sectional shape in the sub-scanning direction (D3-D4 direction) orthogonal to the main scanning direction (D1-D2 direction). In the present embodiment, the arrangement direction of the heating elements 13a is the main scanning direction of the thermal head X. Note that the glaze layer 12 may be at least between the heat generating element 13a and the head substrate 11, and may not be formed on the entire top surface of the head substrate 11.

  The electrical resistance layer 13 is formed on the glaze layer 12. The electric resistance layer 13 has a thickness of 0.01 to 0.5 μm. In the present embodiment, a portion of the electrical resistance layer 13 to which a voltage is applied from the electrode wiring 14 where the electrode wiring 14 is not formed functions as the heating element 13 a, and the heating element 13 a is a protruding portion of the glaze layer 12. 12b is formed. Examples of the material for forming the electric resistance layer 13 include a TaN-based material, a TaSiO-based material, a TaSiNO-based material, a TiSiO-based material, a TiSiCO-based material, and an NbSiO-based material.

  The heat generating element 13 a generates heat when a voltage is applied from the electrode wiring 14. The heat generating element 13a is configured such that a heat generation temperature due to voltage application from the electrode wiring 14 is in a range of 200 to 550 ° C., for example.

  Further, the heating elements 13a are formed in a line at predetermined intervals in the direction of the arrows D1-D2, forming a heating element array. In the present invention, the number of heating element rows may be two or more.

  The electrode wiring 14 includes a first electrode wiring 141, a second electrode wiring 142, and a third electrode wiring 143.

  The end portion of the first electrode wiring 141 is connected to one end side of the plurality of heating elements 13a and a power source (not shown). One end of the first electrode wiring 141 is located on the arrow D3 direction side of the heating element 13a.

  The second electrode wiring 142 has one end connected to the other end of the heat generating element 13 a and the other end connected to the drive IC 20. One end of the second electrode wiring 142 is located on the arrow D4 direction side of the heating element 13a.

  The third electrode wiring 143 is formed away from the second electrode wiring 142, in other words, the third electrode wiring 143 is provided in the vicinity of the second electrode wiring 142. The third electrode wiring 143 is provided between the plurality of driving ICs 20 and the wiring member 30. The third electrode wiring 143 has one end connected to the driving IC 20 and the other end connected to the wiring member 30, and has a function of electrically connecting the driving IC 20 and the wiring member 30. Yes.

  As a material for forming the first electrode wiring 141, the second electrode wiring 142, and the third electrode wiring 143, for example, any one metal of aluminum, gold, silver, copper, or an alloy thereof can be given. The thickness is set to 0.7 to 1.2 μm.

  The protective layer 15 has a function of protecting the heat generating element 13 a and the electrode wiring 14. The protective layer 15 covers the heat generating element 13a and a part of the electrode wiring 14. Examples of the material for forming the protective layer 15 include diamond-like carbon-based materials, SiC-based materials, SiN-based materials, SiCN-based materials, SiAlON-based materials, SiO2-based materials, and TaO-based materials. Is done. Here, the “diamond-like carbon-based material” refers to a material in which the proportion of carbon atoms (C atoms) taking sp3 hybrid orbits is in the range of 1 [atomic%] to less than 100 [atomic%].

  The drive IC 20 has a function of controlling power supply to the plurality of heating elements 13a. The drive IC 20 is connected to the second electrode wiring 142 and the third electrode wiring 143 through a conductive connection member 49 whose connection terminal is made of solder. With such a configuration, the heating element 13a can selectively generate heat in accordance with an electric signal input through the electrode wiring 14.

  As shown in FIG. 3, the connection terminal of the wiring member 30 is connected to the first electrode wiring 141 and the third electrode wiring 143 through a conductive connection member 49 made of solder. The wiring member 30 has a function of transmitting an electric signal transmitted from the outside to the driving IC 20 and the electrode wiring 14. Examples of the electrical signal include power supplied to the heating element 13a and the driving IC 20, and image information for selectively controlling the power supply state of the heating element 13a. The wiring member 30 of this embodiment includes a wiring body 31, an external connection terminal 32, a support plate 33, and an adhesive layer 34.

The wiring body 31 has flexibility, and includes a first wiring body 311, a second wiring body 312, and a wiring portion 313. The first wiring body 311 and the second wiring body 312 have a function of supporting the plurality of wiring portions 313 and ensuring their electrical insulation. The first wiring body 311 and the second wiring body 312 sandwich the wiring portion 313. Examples of a material for forming the first wiring body 311 and the second wiring body 312 include flexible resin materials such as polyimide resin, epoxy resin, and acrylic resin. In the present embodiment, the wiring body 31 is made of a polyimide resin, and its thermal expansion coefficient is about 1.1 × 10 ⁻⁵ K ⁻¹ . As thickness of the 1st wiring body 311 and the 2nd wiring body 312 in this embodiment, the range of 0.5-2.0 mm is mentioned, for example.

Examples of the material for forming the wiring portion 313 include any one kind of metal such as gold, silver, copper, and aluminum, or an alloy thereof. In the present embodiment, the wiring part 313 is made of copper, and its thermal expansion coefficient is about 1.7 × 10 ⁻⁵ K ⁻¹ .

  The external connection terminal 32 is a part to which an electric signal is input from the outside. The external connection terminal 32 is electrically connected to the drive IC 20 and the electrode wiring 14. In FIG. 3, the external connection terminals 32 are not shown for convenience of explanation.

The support plate 33 has a function of supporting the wiring body 31. Examples of a material for forming the support plate 33 include ceramics, resins, ceramics and resin composites. Examples of ceramics include alumina ceramics, aluminum nitride ceramics, silicon carbide ceramics, silicon nitride ceramics, glass ceramics, and mullite sintered bodies. Examples of resins include epoxy resins, polyimide resins, and acrylic resins. Examples thereof include thermosetting types such as resins, phenolic resins, and polyester resins, ultraviolet curable types, and chemical reaction curable types. In the present embodiment, the support plate 33 is made of glass fiber containing an epoxy resin, and has a thermal expansion coefficient of about 1.7 × 10 ⁻⁵ K ⁻¹ .

  The adhesive layer 34 has a function of bonding the wiring body 31 and the support plate 33. Examples of the thickness of the adhesive layer 34 include a range of 10 to 35 μm.

  As shown in FIG. 1, the radiator 40 has a function of transmitting heat generated by driving the heat generating portion 13a to the outside. In the present embodiment, the radiator 40 functions as a support base material for the head base 10 and the wiring member 30. As a material for forming the radiator 40, for example, a metal material containing copper or aluminum can be used. Here, “a material having high thermal conductivity” means a material having higher thermal conductivity than the material constituting the head substrate 11. In particular, from the viewpoint of thermal conductivity, a radiator 40 made of a metal material, particularly aluminum, is desirable.

FIG. 4 is a schematic configuration diagram showing a joined state of the head base 10 and the heat radiating body 40 shown in FIG. As shown in FIG. 4, the head substrate 10 is disposed on the radiator 40, and the adhesive layer 16 and the double-sided tape 17 are interposed between the head substrate 10 and the radiator 40. More specifically, the adhesive layer 16 is interposed between a region (hereinafter referred to as a first region) directly below the heat generating element array on the lower surface of the head base 10 (more specifically, the head substrate 11) and the radiator 40. In addition, the first region and the radiator 40 are bonded to each other while extending in the arrangement direction of the heating elements 13a.
The double-sided tape 17 is interposed between a region other than the first region (hereinafter referred to as a second region) on the lower surface of the head substrate 10 and the heat radiating body 40 and extends in the arrangement direction of the heating elements 13a. And the radiator 40 are bonded. As described above, the reason why the head base 10 is bonded onto the heat radiating body 40 by the adhesive layer 16 and the double-sided tape 17 is that the head base 10 is curved due to the difference in thermal expansion coefficient between the head substrate 11 and the heat radiating body 40. This is because, when a force is applied, the in-plane flexibility of the double-sided tape 17 absorbs the difference in extension between the head base 10 and the heat radiating body 40 due to thermal expansion, and suppresses the bending of the head base 10.

  In FIG. 4A, for convenience of explanation, illustration of the head base 10 shown in FIGS. 4B and 4C is omitted, and in FIG. In FIG. 4C, the head base 10 is shown only by the head substrate 11 and the protruding portion 12 b of the glaze layer 12. In the present embodiment, the adhesive layer 16 and the double-sided tape 17 correspond to the first bonding layer and the second bonding layer in the present invention, respectively.

  Further, as shown in FIG. 1B, the double-sided tape 17 is also interposed between the support plate 33 and the heat radiating body 40, and the support plate 33 and the heat radiating body 40 are bonded by the double-sided tape 17. ing.

  The adhesive layer 16 is formed of an adhesive made of a heat-dissipating resin, such as a silicone resin, an epoxy resin, a polyimide resin, an acrylic resin, a phenol resin, and a polyester resin containing a filler. It is formed of a thermosetting type, a room temperature curing type, or a chemical reaction curing type.

  As shown in FIG. 4, the inside of the adhesive layer 16 has a particle size substantially the same as the thickness of the adhesive layer 16, and is in contact with both the lower surface of the head base 10 and the radiator 40. A plurality of spacer particles 19 are contained. More specifically, each spacer particle 19 has a spherical shape having the same particle diameter, and both end portions of the adhesive layer 16 in the arrangement direction of the heating elements 13a (FIGS. 4A and 4B). Then, four pieces are arranged at each of the left and right end portions), and four pieces are arranged at the central portion. The thermal conductivity of each spacer particle 19 is higher in the spacer particles 19 disposed in the center than in the spacer particles 19 disposed at both ends of the adhesive layer 16. In FIG. 4A, the outer shape of the spacer particle 19 is indicated by a solid line for easy understanding. In the present embodiment, the adhesive layer 16 is a particle-containing layer in the present invention.

  For example, ceramic particles, glass ceramic particles, glass particles, plastic particles, metal particles, and the like are used as the spacer particles 19. From the viewpoint of maintaining the flatness of the head substrate 10, ceramic particles are desirable, and from the viewpoint of scratch resistance. The plastic particles are desirable. The particle diameter of the spacer particles 19 is, for example, 10 to 150 μm. Examples of the ceramic particles include those formed of alumina and zirconia. Examples of the glass ceramic particles include those formed of glass containing alumina as a filler. Examples of the glass particles include those formed of soda glass and borosilicate glass. Examples of the plastic particles include those formed of polyethylene, polypropylene, and divinylbenzene polymer. Examples of the metal particles include those formed of gold, silver, copper, aluminum, and nickel. In addition, when using the spacer particle | grains 19 which consist of a plastic particle, it is desirable to use the plastic particle which coat | covered the surface with the metal as the spacer particle | grain 19 in order to improve heat dissipation.

  In addition, as described above, the thermal conductivity of the spacer particles 19 disposed in the central portion is higher than the thermal conductivity of the spacer particles 19 disposed at both ends of the adhesive layer 16 in the arrangement direction of the heating elements 13a. In order to achieve this, for example, spacer particles 19 made of polypropylene may be arranged at both ends of the adhesive layer 16, and spacer particles 19 made of soda glass may be arranged at the center. Alternatively, for example, the spacer particles 19 at both ends may be formed of alumina, and the spacer particles 19 at the center may be formed of nickel.

  According to the thermal head X of the present embodiment, as described above, the thermal conductivity of the spacer particles 19 is more central than the spacer particles 19 disposed at both ends of the adhesive layer 16 in the arrangement direction of the heating elements 13a. The spacer particles 19 arranged in the part are higher. Therefore, in the head base 10, heat easily escapes from the head base 10 to the spacer particles 19 in the central portion in the arrangement direction of the heat generating elements 13 a that tend to increase heat storage, and the heat transmitted to the spacer particles 19 is further dissipated. Since it escapes to the body 40, the heat dissipation in a center part improves rather than both ends. Thereby, the variation in temperature of each heat generating element 13a in the arrangement direction of the heat generating elements 13a is reduced, and unevenness in the print density of the thermal head X in the arrangement direction of the heat generating elements 13a can be suppressed.

Note that the thermal conductivity of the spacer particles 19 arranged at both ends of the adhesive layer 16 in the arrangement direction of the heating elements 13a and the thermal conductivity of the spacer particles 19 arranged in the central part are the arrangement of the heating elements 13a. It can be set by the temperature difference between the center and both ends of the direction. For example, when the temperature difference is large, the central portion is increased so that the difference in thermal conductivity between the spacer particles 19 disposed at both ends of the adhesive layer 16 and the spacer particles 19 disposed at the central portion is large. The spacer particles 19 having higher thermal conductivity are disposed on the spacers, or the spacer particles 19 having smaller thermal conductivity are disposed on both ends, whereby the temperature of the central portion and both ends of the heating element 13a in the arrangement direction is increased. The difference can be reduced.
<Method for manufacturing recording head>
Next, the recording head manufacturing method of the present invention will be described using the above-described thermal head X as an example.

  First, a mother substrate having a plurality of head substrate regions is prepared. Next, the glaze layer 12 is formed on the entire upper surface of the mother substrate. Examples of the forming method include known methods such as a printing method and a baking method.

  Next, a resistor film is formed on the entire upper surface of the glaze layer 12 formed on each head substrate region. Examples of the film forming method include conventionally known methods including sputtering technology and vapor deposition technology. Next, a conductive film is formed on the entire upper surface of the resistor film. Examples of the method for forming the conductive film include conventionally known methods including sputtering technology and vapor deposition technology.

  Next, the conductive film and the resistor film are etched into a predetermined pattern to form the electrode wiring 14, and then etched again to remove a part of the electrode wiring 14 and expose a part of the resistor film, thereby heating element 13a. To function as. At this time, an element row composed of a plurality of heating elements 13a is arranged along the arrow direction D1-D2. As this etching method, for example, a conventionally known method including a combination of a photoresist technique and a wet etching technique can be cited.

  Next, the protective layer 15 is formed so as to cover the heat generating element 13a and a part of the electrode wiring 14 by a sputtering method.

  Next, the mother substrate is divided into head substrate regions to obtain a plurality of head substrates 11.

  Next, the wiring member 30 is prepared. Specifically, first, a wiring body 31 including a first wiring body 311, a second wiring body 312, and a wiring portion 313 is prepared. Next, an adhesive 34 is applied to the upper surface of the support plate 33, and the wiring body 31 is joined to the support plate 33.

  Next, a solder paste that becomes the conductive connection member 49 is applied on the first electrode wiring 141 and the third electrode wiring 143 of the head substrate 10. Then, the first electrode wiring 141, the third electrode wiring 143, and the connection terminal of the wiring member 30 are opposed to each other through a solder paste and heated to connect the first electrode wiring 141, the third electrode wiring 143 and the wiring member 30. The terminal is fixed with solder that has been melted by heat.

  Next, a solder paste that becomes the conductive connection member 49 is applied to the second electrode wiring 142 and the third electrode wiring 143, and the connection terminal of the driving IC 20 is connected to the second electrode wiring 142 and the third electrode wiring 143 via the solder paste. Face each other. Then, the solder paste is thermally melted, and the second electrode wiring 142 and the third electrode wiring 143 are connected to the connection terminal of the drive IC 20.

  Next, the head base 10 and the wiring member 30 are joined on the heat radiating body 40. This will be specifically described. A heat-dissipating adhesive is applied to the projecting surface between the concave grooves 18 of the radiator 40 in which the concave grooves 18 are formed in the directions of the arrows D <b> 1-D <b> 2 using a coating device such as a dispenser to form the adhesive layer 16. .

  On the other hand, the double-sided tape 17 is affixed to the upper surface of the heat radiating body 40 other than the protruding surface between the concave grooves 18. Thereafter, the spacer particles 19 are disposed on the upper surface of the adhesive layer 16 by a dispenser or the like. At this time, spacer particles 19 having higher thermal conductivity than the spacer particles 19 arranged at both ends are arranged at the center of the upper surface of the adhesive layer 16 in the arrangement direction of the heating elements 13a. Note that the step of applying the heat-dissipating adhesive and the step of applying the double-sided tape 17 may be reversed.

  Then, the head base 10 is disposed on the upper surface of the heat radiating body 40 on which the adhesive layer 16 is formed and the double-sided tape 17 is attached, and the head base 10 is pressed toward the heat radiating body 40. As a result, the spacer particles 19 are buried in the adhesive layer 16 and the lower surface of the head substrate 10 is bonded to the adhesive layer 16 and the double-sided tape 17. By doing so, the spacer particles 19 disposed at the center portion have higher thermal conductivity than the spacer particles 19 disposed at both ends of the adhesive layer 16, and the spacer particles 19 are disposed on the head substrate 10. The adhesive layer 16 is disposed in contact with both the lower surface and the radiator 40.

As described above, the thermal head X of the present embodiment is formed.
<Recording device>
Next, a thermal printer which is an embodiment of the recording apparatus of the present invention will be described with reference to the drawings.

  As shown in FIG. 5, the thermal printer Y of the present embodiment includes the above-described thermal head X, a transport mechanism 59, and a control mechanism 69.

  The transport mechanism 59 has a function of bringing the recording medium P into contact with the heating element 13a of the thermal head X while transporting the recording medium P in the direction of the arrow D3. The transport mechanism 59 includes a platen roller 61 and transport rollers 62, 63, 64, and 65.

  The platen roller 61 has a function of pressing the recording medium P toward the heating element 13a. The platen roller 61 is supported at both ends so as to be rotatable while in contact with the protective layer 15 located on the heating element 13a. The platen roller 61 has a configuration in which an outer surface of a columnar base is covered with an elastic member. This base is made of, for example, a metal such as stainless steel, and this elastic member is made of, for example, butadiene rubber having a thickness of 3 to 15 mm.

  The transport rollers 62, 63, 64 and 65 have a function of transporting the recording medium P. That is, the transport rollers 62, 63, 64, 65 supply the recording medium P between the heating element 13 a of the thermal head X and the platen roller 61, and between the heating element 13 a of the thermal head X and the platen roller 61. It plays a role of pulling out the recording medium P from the recording medium. These transport rollers 62, 63, 64, 65 may be formed by, for example, a metal columnar member. For example, like the platen roller 61, the outer surface of the columnar substrate is covered with an elastic member. There may be.

  The control mechanism 69 has a function of supplying image information to the drive IC 20. That is, the control mechanism 69 plays a role of supplying image information for selectively driving the heat generating portion 13 a to the drive IC 20 via the external connection terminal 32.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning.

  In the thermal head X of the above embodiment, as shown in FIG. 4, the spacer particles 19 are formed at one end (the left end in FIG. 4) and the other end (the right end in FIG. 4) of the adhesive layer 16. 4) are arranged at the center part, and four are arranged at the center part, but the spacer particles 19 arranged at the center part are more thermally conductive than the spacer particles 19 arranged at both end parts. However, the present invention is not limited to this as long as the heat dissipation performance at the central portion is higher than both end portions of the lower surface of the head substrate 10 in the arrangement direction of the heat generating elements 13a. For example, the spacer particles 19 may be arranged one by one or any plural number at one end, the center and the other end of the adhesive layer 16.

  Further, for example, the spacer particles 19 arranged closer to the center portion of the adhesive layer 16 in the arrangement direction (D1-D2 direction) of the heating elements 13a may be configured to have higher thermal conductivity. In this case, for example, as shown in FIG. 6, the adhesive layer 16 is divided into a plurality of (in the illustrated example, five) regions E in the arrangement direction of the heat generating elements 13 a, and the region E closer to the center is more thermally conductive. The spacer particles 19 may be interspersed so that the spacer particles 19 formed of a material having a high rate are arranged. Thus, since the spacer particles 19 are scattered in the arrangement direction of the heat generating elements 13a, an effect of stabilizing the shape of the head base 10 in the arrangement direction of the heat generating elements 13a can be obtained.

  The spacer particles 19 in the adhesive layer 16 are arranged such that the thermal conductivity of the spacer particles 19 is more central than the spacer particles 19 arranged at both ends of the adhesive layer 16 in the arrangement direction of the heating elements 13a. As long as the spacer particles 19 arranged in the portion are higher, there is no particular limitation. For example, as shown in FIG. 6, it may be arranged in a line along the arrangement direction of the heating elements 13a, or may be arranged in a plurality of lines. 4 and 6, the spacer particles 19 are regularly arranged, but may be arranged randomly.

  In the thermal head X of the above embodiment, as shown in FIG. 4, the spacer particles 19 arranged at both ends and the center of the adhesive layer 16 in the arrangement direction of the heating elements 13a are arranged at the same density. For example, as shown in FIG. 7, each spacer particle 19 is formed in a spherical shape having the same particle diameter, and the density of the spacer particles 19 arranged in the adhesive layer 16 is such that the heating element 13a has a density. You may arrange | position so that it may become high in a center part rather than the both ends of the adhesive bond layer 16 in the sequence direction. Thereby, the contact area with the spacer particles 19 per unit area in the bonding region with the adhesive layer 16 on the lower surface of the head substrate 10 is larger at the center than at both ends in the arrangement direction of the heating elements 13a. In this way, for example, when the thermal conductivity of the spacer particles 19 disposed in the central portion of the adhesive layer 16 is increased, the heat dissipation at the central portion of the head base 10 is still insufficient. Heat can be easily released from the substrate 10 to the spacer particles 19 and heat dissipation at the center can be improved.

  The size of the contact area between the lower surface of the head substrate 10 and the spacer particles 19 is such that, for example, only the head substrate 10 is removed from the thermal head X of this embodiment, and the spacer particles 19 exposed from the upper surface of the adhesive layer 16 are removed. It can be calculated by measuring the size of the surface. In addition, the size of the surface of the spacer particle 19 exposed from the adhesive layer 16 can be determined by, for example, performing image analysis by binarization on the upper surface of the adhesive layer 16 including the exposed surface of the spacer particle 19. Can be measured. In the present invention, spacer particles having “the same particle size” include not only particles having the same particle size but also particles having substantially the same particle size, and an error range of ± 5. % Having a particle size of%.

  In FIG. 7, the spacer particles 19 are disposed only at both ends and the center of the adhesive layer 16. For example, the spacer particles 19 approach the center from both ends of the adhesive layer 16 in the arrangement direction of the heating elements 13 a. As the density of the spacer particles 19 gradually increases, the spacer particles 19 are scattered so that the contact area between the head substrate 10 and the spacer particles 19 per unit area of the lower surface of the head substrate 10 is at the center of the lower surface of the head substrate 10. May be maximized.

  In the thermal head X of the above embodiment, as shown in FIG. 4, the spacer particles 19 have a spherical shape. However, the present invention is not limited to this, and examples thereof include a cube, a rectangular parallelepiped, and an octahedron. You may use the spacer particle | grains which comprise a polyhedron. Alternatively, spherical spacer particles and polyhedral spacer particles may be used in combination. When the spacer particles 19 have a polyhedral shape, the contact area between the lower surface of the head substrate 10 and the spacer particles 19 can be increased by bringing one surface of the polyhedron into close contact with the lower surface of the head substrate 10.

  In the thermal head X of the above embodiment, as shown in FIG. 4, the spacer particles 19 are disposed only in the adhesive layer 16, but the present invention is not limited to this, and the adhesive layer 16 and The spacer particles 19 may be contained in at least one of the double-sided tapes 17. For example, as shown in FIG. 8, spacer particles 19 may be arranged in the double-sided tape 17 in addition to the adhesive layer 16. In this case, both the adhesive layer 16 and the double-sided tape 17 serve as the particle-containing layer in the present invention. Alternatively, although not shown, the spacer particles 19 may not be disposed in the adhesive layer 16 but may be disposed only in the double-sided tape 17. In this case, only the double-sided tape 17 becomes the particle-containing layer in the present invention. The size of the contact area between the spacer particles 19 contained in the double-sided tape 17 and the lower surface of the head substrate 10 is, for example, the same as described above, with the head substrate 10 removed and image analysis performed on the upper surface of the double-sided tape 17. It can be measured by doing.

  The spacer particles 19 in the double-sided tape 17 are arranged, for example, on the upper surface of the double-sided tape 17 and the spacer particles 19 on the lower surface of the head substrate 10 in the same manner as the spacer particles 19 in the adhesive layer 16. By pressing, it can be buried in the double-sided tape 17 and brought into contact with the head base 10 and the heat radiating body 40. Therefore, it is desirable to use the double-sided tape 17 having no base material such as a non-woven fabric at the center in the thickness direction. For example, a double-sided tape without a base material using an acrylic adhesive can be used.

  Further, in the thermal head X of the above embodiment, as shown in FIG. 4, the particle diameter of each spacer particle 19 is the same, but is not limited to this, and the particle diameter of each spacer particle 19 is varied. May be. For example, as shown in FIG. 9, the particle size of the spacer particles 19 is such that the spacer particles 19 arranged at the center of the adhesive layer 16 in the arrangement direction (D1-D2 direction) of the heating elements 13a are the heating elements. It may be smaller than the spacer particles 19 arranged at both ends of the adhesive layer 16 in the arrangement direction of 13a. For example, the particle diameter of the spacer particles 19 arranged at the center may be about 0.3 to 0.9 times the particle diameter of the spacer particles 19 arranged at both ends. Since the spacer particles 19 are in contact with both the lower surface of the head substrate 10 and the upper surface of the radiator 40, the distance between the head substrate 10 and the radiator 40 is substantially the same as the particle diameter of the spacer particles 19 positioned therebetween. It becomes size. Accordingly, the distance between the head base 10 and the heat radiating body 40 is narrower at the center than at both ends in the arrangement direction of the heating elements 13a. Therefore, for example, when the thermal conductivity of the spacer particles 19 disposed in the central portion of the adhesive layer 16 is increased, the heat dissipation amount in the central portion of the head base 10 is still insufficient. Heat can be easily released to the spacer particles 19, and heat dissipation at the center can be improved.

  Even if there is some variation in the particle size of the spacer particles 19, the spacer particles 19 may be deformed if they are soft spacer particles such as plastic particles, or may be slightly deformed if they are hard spacer particles such as ceramic particles. By biting into the surface of 40, the heat radiating body 40 and the head base 10 can be brought into contact with each other.

  Further, in the thermal head X shown in FIG. 9, as shown in FIG. 9B, spacer particles 19 having different particle diameters are arranged on the flat upper surface of the radiator 40, so that the upper surface of the head substrate 10 becomes the radiator. Although it is configured to be concave on the 40 side, it is not limited to this. For example, as shown in FIG. 10, the upper surface of the heat radiating body 40 is configured to protrude toward the head substrate 10 at the center portion from both ends in the arrangement direction (D1-D2 direction) of the heat generating elements 13a. The upper surface of the head substrate 10 may be flattened by making the particle size of the spacer particles 19 arranged in the portion smaller than the particle size of the spacer particles 19 arranged at both ends. The head substrate 11 of the head base 10 has a constant thickness. With this configuration, when the radiator 40 and the head base 10 are bonded via the adhesive layer 16 in which the spacer particles 19 having different particle diameters are embedded, the surface of the head base 10, that is, the platen. The heights of the plurality of heat generating elements 13a pressed by the rollers can be the same along the arrangement direction of the heat generating elements 13a.

  Further, as shown in FIG. 11, the upper surface of the heat radiating body 40 is configured to protrude toward the head base 10 at the center portion from both ends in the arrangement direction (D1-D2 direction) of the heat generating elements 13a, By making the spacer particles 19 arranged in the part and the spacer particles 19 arranged in both ends have the same particle size, the upper surface of the head base 10 protrudes at the center part from both ends in the arrangement direction of the heating elements 13a. You may make it make it. The head substrate 11 of the head base 10 has a constant thickness. With this configuration, for example, as shown by a broken line in FIG. 11B, both ends of the platen roller 61 supported at both ends in the arrangement direction of the heating elements 13a Similarly, the recording medium can be sufficiently pressed toward the head substrate 10 side. Therefore, the pressing force applied to the recording medium by the platen roller 61 can be made substantially uniform, and blurring of the print on the recording medium can be suppressed. In FIG. 11B, the platen roller 61 is schematically shown, and the recording medium conveyed between the platen roller 61 and the head base 10 is not shown.

  In the thermal head X of the above embodiment, as shown in FIG. 4, the head substrate 10 (more in detail) on both sides of the adhesive layer 16 in the direction (D3-D4 direction) orthogonal to the arrangement direction of the heating elements 13a. The head substrate 11) is bonded onto the heat radiating body 40 via the double-sided tape 17, but is not limited to this. For example, the head base 10 may be bonded to the heat radiator 40 via the double-sided tape 17 on one side of the adhesive layer 16 in the D3-D4 direction.

  Moreover, in the said embodiment, although the 1st joining layer in this invention is comprised by the adhesive bond layer 16, and the 2nd joining layer in this invention is comprised by the double-sided tape 17, the head base | substrate 10 and the heat radiator 40 are comprised. It is not limited to this as long as it can be joined. For example, the first bonding layer for bonding the first region on the lower surface of the head base 10 and the heat radiating body 40 is formed of a double-sided tape, and the second bonding for bonding the second region on the lower surface of the head base 10 and the heat radiating member 40 is performed. The layer may be composed of an adhesive layer. Moreover, you may comprise both this 1st joining layer and the 2nd joining layer with an adhesive bond layer or a double-sided tape.

X Thermal head (recording head)
Y Thermal printer (recording device)
DESCRIPTION OF SYMBOLS 10 Head base | substrate 11 Head substrate 12 Glaze layer 13 Electrical resistance layer 13a Heating element 14 Electrode wiring 141 1st electrode wiring 142 2nd electrode wiring 143 3rd electrode wiring 15 Protective layer 16 Adhesive layer 17 Double-sided tape 18 Groove 19 Spacer particle 20 Drive IC
30 Wiring member 40 Heat radiating body 59 Conveying mechanism 61 Platen rollers 62, 63, 64, 65 Conveying roller 69 Control mechanism P Recording medium

Claims (10)

A radiator,
A head base that is disposed on the heat dissipating body and has a heat generating element array on which the plurality of heat generating elements are arranged;
A first region that is interposed between the first region immediately below the heating element array on the lower surface of the head base and the heat dissipating member, extends in the arrangement direction of the heat generating elements, and joins the first region and the heat dissipating member. One bonding layer;
A second region which is interposed between the second region other than the first region on the lower surface of the head base and the heat dissipating member, extends in the arrangement direction of the heat generating elements, and joins the second region and the heat dissipating member; A bonding layer,
At least one of the first bonding layer and the second bonding layer is a particle-containing layer that internally contains a plurality of spacer particles that are in contact with both the lower surface of the head substrate and the radiator. ,
The thermal conductivity of the spacer particles is higher in the spacer particles arranged in the central portion than in the spacer particles arranged at both ends of the particle-containing layer in the arrangement direction of the heating elements. .   2. The recording head according to claim 1, wherein the spacer particles have a higher thermal conductivity as the spacer particles are arranged closer to the center of the particle-containing layer in the arrangement direction of the heating elements.   The contact area with the spacer particles per unit area in the bonding region with the particle-containing layer on the lower surface of the head substrate is larger at the center than at both ends in the arrangement direction of the heating elements. The recording head according to claim 1 or 2. The plurality of spacer particles are spherical with the same particle size,
The density of the spacer particles arranged in the particle-containing layer is higher at the center than at both ends of the particle-containing layer in the arrangement direction of the heating elements. Any one of the recording heads.   As for the particle size of the spacer particles, the spacer particles arranged at the center of the particle-containing layer in the arrangement direction of the heating elements are arranged at both ends of the particle-containing layer in the arrangement direction of the heating elements. The recording head according to claim 1, wherein the recording head is smaller than the spacer particles.   6. The recording head according to claim 1, wherein the upper surface of the heat dissipating member protrudes toward the head substrate at a central portion with respect to both end portions in the arrangement direction of the heat generating elements.   The recording head according to claim 1, wherein an upper surface of the head base protrudes at a center portion from both end portions in the arrangement direction of the heat generating elements.   The recording head according to claim 1, wherein the first bonding layer is made of an adhesive.   The recording head according to claim 1, wherein the second bonding layer is made of a double-sided tape. A recording head according to any one of claims 1 to 9, and a platen roller that presses a recording medium onto the heating element of the head substrate,
The recording apparatus, wherein the platen roller is rotatably supported at both ends in the arrangement direction of the heating elements.