JP2012071467A - Thermal head and thermal printer including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal head which can easily adjust the amount of the warpage of a substrate, and a thermal printer including the same.SOLUTION: The thermal head X includes: a head base body 3 having a substrate 7 and a plurality of heat generating parts 9 disposed on the substrate 7; a radiator 1 having a first surface on which the substrate 7 is arranged, a groove 1b which is formed on the first surface along the arrangement direction of the heating parts 9, and a through-hole 1c which is opened on the first surface; a joining layer 33 interposed between the substrate 7 and the first surface of the radiator 1 and joining the substrate 7 and the radiator 1; and an adhesive 35 arranged in the groove 1c of the radiator 1, interposed between the substrate 7 and the groove 1c of the radiator 1, and attaching and fixing the substrate 7 and the radiator 1. The joining layer 33 has a guide 33a for guiding the adhesive 35 to the groove 1b from the through-hole 1c of the radiator 1.

Description

  The present invention relates to a thermal head and a thermal printer including the same.

  Conventionally, various thermal heads have been proposed as printing devices such as facsimiles and video printers. For example, the thermal head described in Patent Document 1 includes a heat radiating plate and a substrate (head substrate) disposed on the heat radiating plate and having a plurality of heating resistors arranged on the upper surface. In this thermal head, a thermosetting resin is filled in a through hole formed in the thickness direction of the heat radiating plate, and the heat radiating plate and the substrate are bonded by the thermosetting resin. Moreover, this through-hole is formed in two places of a heat sink along the sequence direction of a heating resistor.

Japanese Patent Laid-Open No. 8-324015

  When the heat sink and the substrate are bonded as in the thermal head described in Patent Document 1, the heat sink and the substrate may be warped due to the difference in thermal expansion coefficient between the heat sink and the substrate. The amount of warpage varies depending on the position where the heat sink and the substrate are bonded by the thermosetting resin. Specifically, the amount of warpage of the heat sink and the substrate increases as the interval between the positions where the heat sink and the substrate are bonded by the thermosetting resin, that is, the distance between the two through holes formed in the heat sink increases. .

  Here, usually, when printing on a recording medium using a thermal head, the recording medium is pressed onto a plurality of heating resistors by a platen roller. At this time, since the platen roller is bent, the recording medium may not be uniformly pressed onto the heating resistor.

  On the other hand, in the thermal head described in Patent Document 1, by utilizing the fact that the substrate is warped as described above, the row of the plurality of heating resistors is curved in a convex shape so that the pressing force by the platen roller is uniform. It can be considered to be.

  Therefore, in the thermal head described in Patent Document 1, the amount of warpage of the substrate is adjusted so that the pressing force by the platen roller is uniform by appropriately changing the interval between the two through holes formed in the heat radiating plate. It is possible.

  However, in the thermal head described in Patent Document 1, in order to change the interval between the through holes of the heat radiating plate, it is necessary to change the formation position of the through holes, which involves a design change. For this reason, there is a problem that the amount of warpage of the substrate cannot be easily adjusted.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a thermal head that can easily adjust the amount of warping of a substrate and a thermal printer including the thermal head.

A thermal head according to an embodiment of the present invention includes a substrate, a head base having a plurality of heating portions arranged on the substrate, a first surface on which the substrate is arranged, and an arrangement direction of the heating portions. And a heat sink having a groove formed in the first surface along the through-hole opening in the first surface, and interposed between the substrate and the first surface of the heat sink, A bonding layer for bonding the substrate and the heat dissipating member, and being disposed in the groove of the heat dissipating member, interposed between the substrate and the groove of the heat dissipating member, and the substrate and the heat dissipating member. And an adhesive for bonding and fixing, wherein the bonding layer has a guide portion for guiding the adhesive from the through hole of the heat radiating body to the groove.

  In the thermal head according to an embodiment of the present invention, the guide portion may be formed by a notch formed in the bonding layer. The bonding layer may be formed of a double-sided tape. The adhesive may have thermosetting properties.

  In the thermal head according to an embodiment of the present invention, the bonding layer includes two guide portions, and the guide portions are linear with respect to the center of the row including the plurality of heat generating portions. It may be formed symmetrically.

  In the thermal head according to an embodiment of the present invention, the corner formed by the first surface of the heat radiating body and the inner surface of the through hole may be chamfered.

  A thermal printer according to an embodiment of the present invention includes the thermal head according to an embodiment of the present invention, a transport mechanism that transports a recording medium onto the heat generating portion, and a platen that presses the recording medium onto the heat generating portion. And a roller.

  ADVANTAGE OF THE INVENTION According to this invention, the thermal head which can adjust the curvature amount of a board | substrate easily, and a thermal printer provided with the same can be provided.

It is a top view which shows one Embodiment of the thermal head of this invention. It is the II-II sectional view taken on the line of the thermal head of FIG. In the thermal head of FIG. 1, the head substrate, the FPC, the reinforcing plate, and the adhesive are not shown. FIG. 3 illustrates an adhesive in the thermal head of FIG. 2. FIG. 4 illustrates an adhesive in the thermal head of FIG. 3. FIG. 6 is a cross-sectional view of the thermal head of FIG. 4 taken along the line VI-VI, and shows only the heat radiator, the substrate, the bonding layer, and the adhesive. It is a figure which shows schematic structure of one Embodiment of the thermal printer of this invention. It is sectional drawing which shows the modification of the heat radiator shown in FIG. It is a top view which shows the modification of the joining layer shown in FIG. It is a top view which shows the modification of the joining layer shown in FIG.

  Hereinafter, an embodiment of a thermal 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 radiator 1, a head substrate 3 disposed on the radiator 1, and a flexible printed wiring board 5 ( Hereinafter referred to as FPC5). In FIG. 1, illustration of the FPC 5 and a reinforcing plate 39 described later is omitted, and a region where the FPC 5 is disposed is indicated by a two-dot chain line. In FIG. 2, illustration of the adhesive 35 described later is omitted.

The head base 3 has a rectangular substrate 7 in plan view, a plurality of (24 in the illustrated example) heating units 9 provided on the substrate 7 and arranged along the longitudinal direction of the substrate 7, and the heating unit 9. And a plurality (three in the illustrated example) of driving ICs 11 arranged side by side on the substrate 7 along the arrangement direction.

  The substrate 7 is made of an electrically insulating material such as alumina ceramic, a semiconductor material such as single crystal silicon, or the like.

  A heat storage layer 13 is formed on the upper surface of the substrate 7. The heat storage layer 13 includes a base portion 13a formed on the entire top surface of the substrate 7, and a raised portion 13b extending in a strip shape along the arrangement direction of the plurality of heat generating portions 9 and having a substantially semi-elliptical cross section. Yes. The raised portion 13b acts to favorably press the recording medium to be printed against a protective film 25 described later formed on the heat generating portion 9.

  In addition, the heat storage layer 13 is made of, for example, glass having low thermal conductivity, and temporarily accumulates part of the heat generated in the heat generating part 9 to increase the temperature of the heat generating part 9. The time required is shortened and the thermal response characteristic of the thermal head X is enhanced. The heat storage layer 13 is formed, for example, by applying a predetermined glass paste obtained by mixing a glass powder with an appropriate organic solvent onto the upper surface of the substrate 7 by screen printing or the like, and baking it at a high temperature. Is done.

  As shown in FIG. 2, an electrical resistance layer 15 is provided on the upper surface of the heat storage layer 13. The electrical resistance layer 15 is interposed between the heat storage layer 13 and a common electrode wiring 17, an individual electrode wiring 19, and an IC-FPC connection wiring 21 which will be described later. As shown in FIG. A region (hereinafter referred to as an intervening region) having the same shape as the common electrode wiring 17, the individual electrode wiring 19, and the IC-FPC connection wiring 21, and a plurality of (in the illustrated example, exposed from between the common electrode wiring 17 and the individual electrode wiring 19). 24 areas) (hereinafter referred to as exposed areas). In FIG. 1, the intervening region of the electric resistance layer 15 is hidden by the common electrode wiring 17, the individual electrode wiring 19, and the IC-FPC connection wiring 21.

  Each exposed region of the electrical resistance layer 15 forms the heat generating portion 9 described above. The plurality of exposed regions (heat generating portions 9) are arranged in a row on the raised portion 13b of the heat storage layer 13 as shown in FIG. The plurality of heat generating portions 9 are illustrated in a simplified manner in FIG. 1 for convenience of explanation, but are arranged at a density of 180 dpi to 2400 dpi (dot per inch), for example.

  The electric resistance layer 15 is made of a material having a relatively high electric resistance, such as TaN, TaSiO, TaSiNO, TiSiO, TiSiCO, or NbSiO. Therefore, when a voltage is applied between the common electrode wiring 17 and the individual electrode wiring 19 which will be described later and a current is supplied to the heat generating portion 9, the heat generating portion 9 generates heat due to Joule heat generation.

  As shown in FIGS. 1 and 2, the common electrode wiring 17, the plurality of individual electrode wirings 19, and the plurality of IC-FPC connections are provided on the upper surface of the electric resistance layer 15 (more specifically, the upper surface of the intervening region). A wiring 21 is provided. The common electrode wiring 17, the individual electrode wiring 19, and the IC-FPC connection wiring 21 are formed of a conductive material. For example, any one metal of aluminum, gold, silver, and copper, or these It is made of an alloy.

The common electrode wiring 17 is for connecting the plurality of heat generating portions 9 and the FPC 5. As shown in FIG. 1, the common electrode wiring 17 includes a main wiring portion 17 a extending along one long side (the left long side in the illustrated example) of the substrate 7, and one and the other short sides of the substrate 7. Extending along each of the two sub-wiring portions 17b whose one end (the left-hand end in the illustrated example) is connected to the main wiring portion 17a, and individually extending from the main wiring portion 17a toward each heat generating portion 9, The front end portion (right end portion in the illustrated example) has a plurality of (24 in the illustrated example) lead portions 17 c connected to the heat generating portions 9. And this common electrode wiring 17 electrically connects between FPC5 and each heat-emitting part 9 by connecting the other end part (right side edge part in FIG. 1) of subwiring part 17b to FPC5. ing.

  The plurality of individual electrode wirings 19 are for connecting each heat generating part 9 and the drive IC 11. As shown in FIG. 1 and FIG. 2, each individual electrode wiring 19 has one end (left end in the illustrated example) connected to the heat generating unit 9 and the other end (right end in the illustrated) is driven. In order to be arranged in the arrangement area of the ICs 11, the heating parts 9 individually extend in a band shape toward the arrangement area of the driving ICs 11. Then, the other end portion of each individual electrode wiring 19 is connected to the drive IC 11, whereby the heat generating portions 9 and the drive IC 11 are electrically connected. More specifically, the individual electrode wiring 19 divides a plurality of heat generating portions 9 into a plurality of groups (three in the illustrated example), and the heat generating portions 9 of each group are connected to a drive IC 11 provided corresponding to each group. Electrically connected.

  The plurality of IC-FPC connection wirings 21 are for connecting the driving IC 11 and the FPC 5. As shown in FIGS. 1 and 2, each IC-FPC connection wiring 21 has one end portion (left end portion in the illustrated example) disposed in a region where the drive IC 11 is disposed, and the other end portion (right end portion in the illustrated example). Part) extends in a strip shape so as to be arranged in the vicinity of the other long side of the substrate 7 (the long side on the right side in the illustrated example). The plurality of IC-FPC connection wires 21 are electrically connected between the drive IC 11 and the FPC 5 by connecting one end to the drive IC 11 and the other end to the FPC 5. Yes.

  More specifically, the plurality of IC-FPC connection wirings 21 connected to each driving IC 11 are configured by a plurality of wirings having different functions. Specifically, the plurality of IC-FPC connection wirings 21 include, for example, an IC power supply wiring for supplying a power supply current for operating the driving IC 11, a driving IC 11, and an individual electrode wiring connected to the driving IC 11. A ground electrode wiring for holding 19 at a ground potential (for example, 0 V to 1 V) and an electric signal for operating the driving IC 11 so as to control an on / off state of a switching element in the driving IC 11 to be described later are supplied. IC control wiring for this purpose.

  As shown in FIGS. 1 and 2, the drive IC 11 is disposed corresponding to each group of the plurality of heat generating portions 9, and the other end portion (right end portion in the illustrated example) of the individual electrode wiring 19. It is connected to one end portion (left end portion in the illustrated example) of the IC-FPC connection wiring 21. This drive IC 11 is for controlling the energization state of each heat generating part 9, and has a plurality of switching elements inside, and is energized when each switching element is in an on state. A well-known thing which becomes a non-energized state in an OFF state can be used.

  Each drive IC 11 is provided with a plurality of switching elements (not shown) therein so as to correspond to each individual electrode wiring 19 connected to each drive IC 11. As shown in FIG. 2, each drive IC 11 has one connection terminal 11a (hereinafter referred to as the first connection terminal 11a) connected to each switching element (not shown) as an individual electrode wiring. 19 and the other connection terminal 11b (hereinafter, the second connection terminal 11b) connected to each switching element is connected to the ground electrode wiring of the IC-FPC connection wiring 21. It is connected. Thereby, when each switching element of the drive IC 11 is in the ON state, the individual electrode wiring 19 connected to each switching element and the ground electrode wiring of the IC-FPC connection wiring 21 are electrically connected.

The electric resistance layer 15, the common electrode wiring 17, the individual electrode wiring 19 and the IC-FPC connection wiring 21 are formed by, for example, a conventionally well-known thin film forming method such as a sputtering method on the heat storage layer 13. After sequentially laminating by a technique, this laminate is formed by processing it into a predetermined pattern using a conventionally known photoetching or the like. The common electrode wiring 17, the individual electrode wiring 19, and the IC-FPC connection wiring 21 can be simultaneously formed by the same process.

  As shown in FIGS. 1 and 2, on the heat storage layer 13 formed on the upper surface of the substrate 7, a protective film 25 covering the heat generating portion 9, a part of the common electrode wiring 17 and a part of the individual electrode wiring 19. Is formed. In FIG. 1, for convenience of explanation, the formation region of the protective film 25 is indicated by a one-dot chain line, and illustration of these is omitted. In the illustrated example, the protective film 25 is provided so as to cover the left region of the upper surface of the heat storage layer 13. More specifically, the heat generating portion 9, the main wiring portion 17a of the common electrode wiring 17, the partial region (left region) of the sub wiring portion 17b, the lead portion 17c, and the partial region of the individual electrode wiring 19 ( A protective film 25 is formed on the left region.

  The protective film 25 protects the area covered with the heat generating portion 9, the common electrode wiring 17 and the individual electrode wiring 19 from corrosion due to adhesion of moisture or the like contained in the atmosphere and wear due to contact with the recording medium to be printed. Is to do. The protective film 25 can be formed of, for example, a SiC-based material, a SiN-based material, a SiO-based material, or a SiON-based material. Further, the protective film 25 can be formed by using a conventionally well-known thin film forming technique such as a sputtering method or a vapor deposition method, or a thick film forming technique such as a screen printing method. The protective film 25 may be formed by laminating a plurality of material layers.

  As shown in FIGS. 1 and 2, a coating layer 27 that partially covers the common electrode wiring 17, the individual electrode wiring 19, and the IC-FPC connection wiring 21 on the heat storage layer 13 formed on the upper surface of the substrate 7. Is provided. In FIG. 1, for convenience of explanation, the formation region of the coating layer 27 is indicated by a one-dot chain line, and illustration thereof is omitted. In the illustrated example, the coating layer 27 is provided so as to partially cover a region on the right side of the protective film 25 on the upper surface of the heat storage layer 13. The coating layer 27 protects the region covered with the common electrode wiring 17, the individual electrode wiring 19, and the IC-FPC connection wiring 21 from oxidation due to contact with the atmosphere and corrosion due to adhesion of moisture contained in the atmosphere. Is to do. The covering layer 27 is formed so as to overlap the end portion of the protective film 25 as shown in FIG. 2 in order to ensure the protection of the common electrode wiring 17 and the individual electrode wiring 19. The covering layer 27 can be formed of a resin material such as an epoxy resin or a polyimide resin, for example. The covering layer 27 can be formed using a thick film forming technique such as a screen printing method.

  As shown in FIGS. 1 and 2, the sub-wiring portion 17b of the common electrode wiring 17 for connecting the FPC 5 described later and the end of the IC-FPC connecting wiring 21 are exposed from the covering layer 27, which will be described later. Thus, the FPC 5 is connected.

  Further, an opening 27a (see FIG. 2) for exposing the end portions of the individual electrode wiring 19 and the IC-FPC connection wiring 21 for connecting the driving IC 11 is formed in the coating layer 27, and this opening 27a. These wirings are connected to the driving IC 11 via the. In addition, the drive IC 11 is connected to the individual electrode wiring 19 and the IC-FPC connection wiring 21 to protect the drive IC 11 itself and to protect the connection portion between the drive IC 11 and these wirings. It is sealed by being covered with a covering member 29 made of resin such as resin.

  3 does not show the head base 3, the FPC 5, and the reinforcing plate 39 in the thermal head X of FIG. In FIG. 3, illustration of an adhesive 35 to be described later is omitted.

As shown in FIGS. 1 to 3, the heat radiator 1 is formed in a plate shape and has a rectangular shape in plan view. The radiator 1 is made of, for example, a metal material such as copper or aluminum, and radiates a part of the heat generated in the heat generating portion 9 of the head base 3 that does not contribute to printing as will be described later. It has a function. In the present embodiment, the radiator 1 is formed of a metal material having a thermal expansion coefficient larger than that of the substrate 7 of the head base 3.

  A first groove 1 a and a second groove 1 b are formed on the upper surface (first surface) of the radiator 1 along the longitudinal direction of the radiator 1. As shown in FIGS. 1 to 3, the first groove 1 a extends along the left edge of the radiator 1. The first groove 1a is formed of a resin that forms a heat-dissipating resin layer 31 interposed between the substrate 7 and the radiator 1 when the substrate 7 of the head base 3 is bonded onto the radiator 1 as described later. When protruding from the upper surface of the radiator 1, the protruding resin is accommodated.

  The 2nd groove | channel 1b is located in the center side of the heat radiator 1 rather than the 1st groove | channel 1a, as shown in FIGS. 1-3. As will be described later, when the substrate 7 of the head base 3 is bonded onto the radiator 1, the second groove 1b is located between the first base 1a and the first base 1a in plan view as shown in FIG. It is formed at a predetermined interval from the first groove 1a so that three heat generating portions 9 can be arranged. In the second groove 1b, an adhesive 35 to be described later is arranged. In the present embodiment, the second groove 1b corresponds to a groove formed on the first surface in the present invention.

  As shown in FIGS. 2 and 3, the radiator 1 is formed with two through holes 1 c that penetrate in the thickness direction of the radiator 1 and open on the upper surface and the lower surface of the radiator 1. The two through holes 1c are located on the right side of the second groove 1b and in the vicinity of the second groove 1b, and are disposed along the second groove 1b.

  As shown in FIGS. 1 and 2, the above-described substrate 7 of the head base 3 is disposed on the upper surface (first surface) of the radiator 1. The radiator 1 and the substrate 7 are bonded via the heat-dissipating resin layer 31 and the bonding layer 33 so that the longitudinal direction of the radiator 1 and the longitudinal direction of the substrate 7 coincide with each other. Thereby, the 1st groove | channel 1a and the 2nd groove | channel 1b of the thermal radiation body 1 are arrange | positioned so that it may extend along the sequence direction of the heat-emitting part 9. FIG.

  Further, as shown in FIG. 1, the heat dissipating body 1 and the substrate 7 are arranged such that the heat generating portion 9 of the head base 3 is disposed between the first groove 1a and the second groove 1b in plan view, The through-holes 1c are joined so as to be arranged in line symmetry with respect to the center of the row composed of the plurality of heat generating portions 9.

  As shown in FIGS. 2 and 3, the heat-dissipating resin layer 31 is disposed in a region between the first groove 1 a and the second groove 1 b on the upper surface of the heat dissipating body 1, and directly below the heat-generating portion 9. And extends in a band shape along the arrangement direction of the heat generating portions 9 of the head base 3. The heat radiating resin layer 31 is interposed between the substrate 7 of the head base 3 and the heat radiating body 1, and joins the substrate 7 and the heat radiating body 1. The heat-dissipating resin layer 31 is formed of a heat-dissipating resin, and releases a part of the heat that does not contribute to printing out of the heat generated in the heat generating portion 9 of the head base 3 to the heat dissipating body 1 as described later. Acts as follows. The heat-dissipating resin layer 31 is, for example, a thermosetting, room-temperature curable, or chemical reaction curable resin such as a silicone resin, an epoxy resin, a polyimide resin, an acrylic resin, a phenol resin, and a polyester resin. It is formed of a filler containing a relatively high thermal conductivity such as alumina.

  As shown in FIGS. 2 and 3, the bonding layer 33 is disposed in a region on the right side of the second groove 1 b on the upper surface of the radiator 1, and along the arrangement direction of the heat generating portions 9 of the head base 3. It extends in a band shape. Similar to the heat-dissipating resin layer 31, the bonding layer 33 is interposed between the substrate 7 of the head base 3 and the heat radiator 1, and bonds the substrate 7 and the heat radiator 1. The bonding layer 33 is formed of a known double-sided tape. An example of this double-sided tape is one using an acrylic adhesive.

  The heat-dissipating resin layer 31 and the bonding layer 33 are softer than an adhesive 35 (described later) interposed between the substrate 7 and the heat dissipating body 1 of the head base 3. It is fixed by bonding with an adhesive 35 described later. That is, the substrate 7 and the radiator 1 are positioned by the adhesive 35 described later.

  Further, as shown in FIGS. 2 and 3, the bonding layer 33 has a notch 33 a formed at a position corresponding to the through hole 1 c of the radiator 1. The notch 33a is formed by notching an edge portion of the bonding layer 33 located on the second groove 1b side. Thereby, as shown in FIG. 3, the opening part of the through-hole 1c of the thermal radiation body 1 is exposed from the joining layer 33, and the through-hole 1c and the 2nd groove | channel 1b pass through the space inside the notch 33a. They are connected in a series of spaces.

  As shown in FIGS. 4 to 6, an adhesive 35 is disposed in the second groove 1 b of the radiator 1. The adhesive 35 is interposed between the substrate 7 of the head base 3 and the radiator 1 and adheres and fixes the substrate 7 and the radiator 1. The adhesive 35 is made of, for example, a thermosetting epoxy resin adhesive or a urethane resin adhesive. 4 shows the adhesive 35 in the thermal head of FIG. FIG. 5 illustrates the adhesive 35 in the thermal head of FIG. 6 is a cross-sectional view taken along the line VI-VI of the thermal head X of FIG. 4, and shows only the radiator 1, the substrate 7, the bonding layer 33, and the adhesive 35 of the thermal head X.

  As shown in FIGS. 1 and 2, the adhesive 35 penetrates the lower surface of the radiator 1 after bonding the substrate 7 of the head base 3 to the radiator 1 via the heat-dissipating resin layer 31 and the bonding layer 33. By injecting the adhesive 35 from the opening of the hole 1c, the adhesive 35 is disposed in the second groove 1b as shown in FIGS. More specifically, by injecting the adhesive 35 into the through hole 1c in this way, the adhesive 35 flows into the notch 33a of the bonding layer 33, and the notch 33a causes the adhesive 35 to be in the second state. Guided to the groove 1b. As a result, the adhesive 35 is disposed in the second groove 1 b and is interposed between the substrate 7 and the radiator 1. In the present embodiment, the guide portion in the present invention is formed by the notch 33 a formed in the bonding layer 33.

  Thus, since the adhesive 35 interposed between the substrate 7 and the radiator 1 has thermosetting properties, it is cured by heating. At this time, the substrate 7 and the radiator 1 are also heated with the heating of the adhesive 35. And in this embodiment, since the thermal expansion coefficient of the heat radiator 1 is larger than the thermal expansion coefficient of the board | substrate 7, the heat radiator 1 and the board | substrate 7 adhere | attach in the state which the heat radiator 1 thermally expanded larger than the board | substrate 7. It is fixed by the agent 35. And when the heat radiator 1 and the board | substrate 7 are cooled in the state fixed in this way, the heat radiator 1 will shrink more largely than the board | substrate 7. FIG. Therefore, as shown in FIG. 6, the substrate 7 and the radiator 1 are warped so that the upper surfaces of the substrate 7 and the radiator 1 are convex, and the substrate 7 is fixed in a state where the substrate 7 is warped. Is done.

  Note that the substrate 7 and the radiator 1 are partially bonded and fixed with the adhesive 35 in this way, and the other portions are bonded with the heat-dissipating resin layer 31 and the bonding layer 33 that are softer than the adhesive 35. The reason is that after the substrate 7 and the radiator 1 are fixed with the adhesive 35, a force that causes warping of the head base 3 due to the difference in elongation between the substrate 7 and the radiator 1 due to thermal expansion acts. When this is done, the in-plane flexibility of the heat-dissipating resin layer 31 and the bonding layer 33 alleviates the shear stress generated between the substrate 7 and the heat dissipating body 1 and reduces unintended warping of the head base 3. It is.

As shown in FIGS. 1 and 2, the FPC 5 extends along the longitudinal direction of the substrate 7 and is connected to the sub-wiring portion 17b of the common electrode wiring 17 and each IC-FPC connection wiring 21 as described above. Yes. This FPC 5 is a well-known one in which a plurality of printed wirings are wired inside an insulating resin layer, and each printed wiring is electrically connected to an external power supply device and control device (not shown) via a connector 37. It has come to be. Such a printed wiring is generally formed of, for example, a metal foil such as a copper foil, a conductive thin film formed by a thin film forming technique, or a conductive thick film formed by a thick film printing technique. Moreover, the printed wiring formed by a metal foil, a conductive thin film, or the like is patterned by, for example, partially etching these by photoetching or the like.

  More specifically, as shown in FIG. 1 and FIG. 2, the FPC 5 has a conductive bonding material in which each printed wiring 5b formed inside the insulating resin layer 5a is exposed at the end on the head base 3 side. For example, the sub-wiring portion of the common electrode wiring 17 is made of a bonding material 32 (see FIG. 2) made of, for example, a solder material or an anisotropic conductive material (ACF) in which conductive particles are mixed in an electrically insulating resin. It is connected to the end of 17b and the end of each IC-FPC connection wiring 21.

  When each printed wiring 5b of the FPC 5 is electrically connected to an external power supply device and control device (not shown) via the connector 37, the common electrode wiring 17 is held at a positive potential (for example, 20V to 24V). The individual electrode wiring 19 is electrically connected to the positive terminal of the power supply apparatus, and the individual electrode wiring 19 is held at a ground potential (for example, 0 V to 1 V) via the ground electrode wiring of the driving IC 11 and the IC-FPC connection wiring 21. It is electrically connected to the negative terminal of the device. For this reason, when the switching element of the drive IC 11 is in the on state, a current is supplied to the heat generating portion 9 and the heat generating portion 9 generates heat.

  Similarly, when each printed wiring 5b of the FPC 5 is electrically connected to an external power supply device and a control device (not shown) via the connector 37, the IC power supply wiring of the IC-FPC connection wiring 21 is Similar to the common electrode wiring 17, it is electrically connected to the positive side terminal of the power supply device held at a positive potential. As a result, the power supply current for operating the drive IC 11 is supplied to the drive IC 11 by the potential difference between the IC power supply wiring and the ground electrode wiring of the IC-FPC connection wiring 21 to which the drive IC 11 is connected. Further, the IC control wiring of the IC-FPC connection wiring 21 is electrically connected to an external control device that controls the driving IC 11. As a result, the electrical signal transmitted from the control device is supplied to the drive IC 11. By operating the drive IC 11 so as to control the on / off state of each switching element in the drive IC 11 by this electric signal, each heat generating portion 9 can be selectively heated.

  As shown in FIG. 2, a reinforcing plate 39 made of a resin such as a phenol resin, a polyimide resin, a polyester resin, or a glass epoxy resin is provided between the FPC 5 and the radiator 1. The reinforcing plate 39 acts to reinforce the FPC 5 by being adhered to the lower surface of the FPC 5 with a double-sided tape, an adhesive, or the like (not shown). In addition, the reinforcing plate 39 is bonded to the upper surface of the radiator 1 by the bonding layer 33. As a result, the FPC 5 is fixed on the radiator 1.

  Next, an embodiment of the thermal printer of the present invention will be described with reference to FIG. FIG. 7 is a schematic configuration diagram of the thermal printer Z of the present embodiment.

  As shown in FIG. 7, the thermal printer Z of the present embodiment includes the thermal head X, the transport mechanism 40, the platen roller 50, the power supply device 60, and the control device 70 described above. The thermal head X is attached to an attachment surface 80a of an attachment member 80 provided in a housing (not shown) of the thermal printer Z. The thermal head X is arranged so that the arrangement direction of the heat generating portions 9 is along a direction (main scanning direction) (direction perpendicular to the paper surface of FIG. 7) perpendicular to the conveyance direction S of the recording medium P described later. It is attached to the attachment member 80.

The transport mechanism 40 transports a recording medium P such as thermal paper or image receiving paper onto which ink is transferred in the direction of arrow S in FIG. 25) and has conveying rollers 43, 45, 47, and 49. The transport rollers 43, 45, 47, and 49 cover cylindrical shaft bodies 43a, 45a, 47a, and 49a made of metal such as stainless steel with elastic members 43b, 45b, 47b, and 49b made of butadiene rubber, for example. Can be configured. Although not shown, when the recording medium P is an image receiving paper to which ink is transferred, an ink film is transported together with the recording medium P between the recording medium P and the heat generating portion 9 of the thermal head X. Yes.

  The platen roller 50 is for pressing the recording medium P onto the heat generating portion 9 of the thermal head X, and is arranged so as to extend along a direction orthogonal to the conveyance direction S of the recording medium P. Both ends are supported so as to be rotatable while being pressed on the heat generating portion 9. The platen roller 50 can be configured by, for example, covering a cylindrical shaft body 50a made of metal such as stainless steel with an elastic member 50b made of butadiene rubber or the like.

  The power supply device 60 is for supplying a current for causing the heat generating part 9 of the thermal head X to generate heat and a current for operating the drive IC 11 as described above. The control device 70 is for supplying the drive IC 11 with a control signal for controlling the operation of the drive IC 11 in order to selectively heat the heat generating portion 9 of the thermal head X as described above.

  As shown in FIG. 7, the thermal printer Z according to the present embodiment presses the recording medium P onto the heat generating portion 9 of the thermal head X by the platen roller 50, and moves the recording medium P onto the heat generating portion 9 by the transport mechanism 40. A predetermined printing can be performed on the recording medium P by selectively causing the heat generating unit 9 to generate heat by the power supply device 60 and the control device 70 while being conveyed. When the recording medium P is an image receiving paper or the like, printing on the recording medium P can be performed by thermally transferring ink of an ink film (not shown) conveyed together with the recording medium P to the recording medium P.

  According to the thermal head X of the present embodiment, the bonding layer 33 that bonds the substrate 7 of the head base 3 and the radiator 1 guides the adhesive 35 from the through hole 1c of the radiator 1 to the second groove 1b. A notch 33a (guide portion) is provided. Therefore, according to the present embodiment, the adhesive 35 can be guided from the through hole 1c of the radiator 1 to the second groove 1b when the radiator 1 and the substrate 7 are bonded by the adhesive 35. Thereby, after bonding the radiator 1 and the substrate 7 by the bonding layer 33, the adhesive 35 can be poured into the second groove 1 b from the through hole 1 c of the radiator 1. Therefore, after temporarily dissipating the radiator 1 and the substrate 7 with the bonding layer 33, the radiator 1 and the substrate 7 can be bonded and fixed with the adhesive 35.

  Furthermore, according to the thermal head X of the present embodiment, when the radiator 1 and the substrate 7 are bonded by the adhesive 35, the amount of the adhesive 35 flowing into the second groove 1b is adjusted, and the second By making the adhesive 35 exist in a predetermined range in the groove 1b, the amount of warpage of the substrate 7 in the arrangement direction of the heat generating portions 9 can be adjusted. That is, when the radiator 1 and the substrate 7 are bonded, the radiator 1 and the substrate 7 are warped due to the difference in the coefficient of thermal expansion between the radiator 1 and the substrate 7 as described above. The amount of warpage varies depending on the position at which the radiator 1 and the substrate 7 are bonded by the adhesive 35. Specifically, the more the region where the radiator 1 and the substrate 7 are bonded by the adhesive 35 is located farther from the center of the substrate 7 in the arrangement direction of the heat generating portions 9, the more the warp of the radiator 1 and the substrate 7 is. The amount increases. Therefore, by adjusting the amount of the adhesive 35 that flows into the second groove 1b as described above, the warpage amount of the substrate 7 in the arrangement direction of the heat generating portions 9 can be easily adjusted. Therefore, it is not necessary to change the formation position of the through hole 1c of the heat radiating body 1 as in the conventional example, and the amount of warpage of the substrate 7 can be easily adjusted.

  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, the bonding layer 33 is formed of a double-sided tape, but the present invention is not limited to this. For example, the bonding layer 33 may be formed of a resin layer formed by screen printing or the like.

  Moreover, in the thermal head X of the said embodiment, as shown in FIG. 8, the angle | corner formed by the upper surface (1st surface) of the heat radiator 1 and the inner surface of the through-hole 1c may be chamfered. In FIG. 8, this chamfered portion is denoted by reference numeral 1d. By forming the chamfered portion 1d in this way, the adhesive 35 (not shown) injected into the through hole 1c can easily flow toward the second groove 1b. Further, although not shown, the corner formed by the upper surface of the radiator 1 and the second groove 1b may be chamfered.

  Further, in the thermal head X of the above embodiment, the bonding layer 33 has two notches 33a as shown in FIG. 3, but the present invention is not limited to this. For example, as shown in FIG. Only one through hole 1c of the radiator 1 may be formed, and the bonding layer 33 may have only one notch 33a in accordance with this. Alternatively, although not shown, three or more through holes 1c of the radiator 1 may be formed, and the bonding layer 33 may have three or more notches 33a in accordance with this. Alternatively, although not shown, a plurality of through holes 1c of the heat radiating body 1 are formed at positions corresponding to one notch 33a, and the openings of the plurality of through holes 1c are arranged so as to be continuous with one notch 33a. It may be.

  In the thermal head X of the above embodiment, the guide portion in the present invention is formed by forming a notch 33a in the bonding layer 33 as shown in FIG. As long as it can guide from the hole 1c to the 2nd groove | channel 1b, it is not limited to this. For example, as shown in FIG. 10, by forming a groove 33b extending in the bonding layer 33 so as to connect between the opening of the through hole 1c of the radiator 1 and the opening of the second groove 1b, the guide in the present invention. A part may be formed. Thereby, the through-hole 1c and the 2nd groove | channel 1b are connected by a series of space via the space inside the groove | channel 33b. Note that the groove 33b of the bonding layer 33 is formed symmetrically with respect to the center of the row of the plurality of heat generating portions 9 in the same manner as the notch 33a shown in FIG.

  Moreover, in the thermal head X of the said embodiment, as shown in FIGS. 1-3, the through-hole 1c of the heat radiator 1 is formed in the right side of the 2nd groove | channel 1b, and the joining layer 33 is also 2nd according to this. However, the present invention is not limited to this. For example, although not shown, if it demonstrates with reference to FIGS. 1-3, the through-hole 1c of the thermal radiation body 1 will be formed between the 1st groove | channel 1a and the 2nd groove | channel 1b, and heat dissipation will be carried out according to this. Instead of the conductive resin layer 31, the bonding layer 33 may be disposed between the first groove 1a and the second groove 1b. In this case, the notch 33 a of the bonding layer 33 is arranged on the second groove 1 b side of the bonding layer 33.

X Thermal Head 1 Heat Dissipator 1a First Groove 1b Second Groove 1c Through Hole 3 Head Substrate 5 Flexible Printed Circuit Board 7 Substrate 9 Heating Part 11 Drive IC
DESCRIPTION OF SYMBOLS 13 Heat storage layer 15 Electrical resistance layer 17 Common electrode wiring 17a Main wiring part 17b Sub wiring part 17c Lead part 19 Individual electrode wiring 21 IC-FPC connection wiring 25 Protective film 27 Covering layer 29 Covering member 31 Heat radiation resin layer 33 Bonding layer 33a Notch (guide section)
33b Groove (guide section)
35 Adhesive 37 Connector 39 Reinforcing plate

Claims (7)

A head body having a substrate and a plurality of heat generating portions arranged on the substrate;
A radiator having a first surface on which the substrate is disposed, a groove formed in the first surface along the arrangement direction of the heat generating portions, and a through-hole opened in the first surface;
A bonding layer interposed between the substrate and the first surface of the radiator, and bonding the substrate and the radiator;
An adhesive that is disposed in the groove of the radiator and is interposed between the substrate and the groove of the radiator to bond and fix the substrate and the radiator;
The thermal bonding head according to claim 1, wherein the bonding layer has a guide portion for guiding the adhesive from the through hole of the heat radiating body to the groove.   The thermal head according to claim 1, wherein the guide portion is formed by a notch formed in the bonding layer.   The thermal head according to claim 1, wherein the bonding layer is formed of a double-sided tape.   The thermal head according to claim 1, wherein the adhesive has thermosetting properties. The bonding layer has two guide portions,
5. The thermal head according to claim 1, wherein the guide portion is formed in line symmetry with respect to a center of the row of the plurality of heat generating portions.   6. The thermal head according to claim 1, wherein a corner formed by the first surface of the heat radiating body and an inner surface of the through hole is chamfered. A thermal head comprising: the thermal head according to claim 1; a transport mechanism that transports a recording medium onto the heat generating portion; and a platen roller that presses the recording medium onto the heat generating portion. Printer.

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