JP2017043076A - Thermal head and thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal head in which a crack hardly occurs in a coating member while improving the bond strength of a wiring board.SOLUTION: A thermal head X1 includes: a head base 3 which has a substrate 7, a heating part and an electrode; a wiring board 6 which has a wiring conductor; a heat sink 1 which is arranged on the lower side of the head base 3 and wiring board 6; a conductive member for electrically connecting the electrode and the wiring conductor; and a coating member 29. The wiring board 6 includes: a first surface face 6d which extends in the main-scanning direction; and a second side face 6e which extends in the sub-scanning direction. A notch 6g apart from the first side face 6d is provided on the second side face 6e. The coating member 29 is provided on the notch 6g. The coating member 29 provided on the notch 6g is joined to the heat sink 1. The coating member 29 provided on the heat sink 1 is apart from the head base 3. Consequently, a crack hardly occurs on the coating member 29 while improving the bond strength of the wiring board 6.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a thermal head and a thermal printer.

  Conventionally, various thermal heads have been proposed as printing devices such as facsimiles and video printers. For example, a substrate, a heat generating part provided on the substrate, a head base provided on the substrate and electrically connected to the heat generating part, and a wiring conductor electrically connected to the electrode of the head base A wiring board, a heat sink disposed below the head substrate and the wiring board, a conductive member for electrically connecting the electrode and the wiring conductor, and a covering member for covering the conductive member A thermal head is known (see Patent Document 1). In the above thermal head, the substrate is bonded to the heat radiating plate, and the covering member is applied so as to cover the side surface portion of the contact portion between the substrate and the wiring substrate. Thereby, the bonding strength of the wiring board is improved.

JP 07-28650 A

  However, the heat sink has a larger coefficient of thermal expansion than the substrate, and stress concentrates on the side surface of the bonded substrate due to a temperature cycle during manufacturing or driving. Therefore, when the covering member is disposed so as to cover the side surface portion of the substrate, stress concentrates on the covering member, and there is a possibility that the covering member may crack.

  A thermal head according to an embodiment of the present invention includes a substrate, a heat generating portion provided on the substrate, and a head base having an electrode provided on the substrate and electrically connected to the heat generating portion; A wiring board having a wiring conductor electrically connected to the electrode of the head base, a heat sink disposed below the head base and the wiring board, and electrically connecting the electrode and the wiring conductor. A conductive member for covering, and a covering member for covering the conductive member. The wiring board has a rectangular main surface, and has a first side surface extending in the main scanning direction and a second side surface extending in the sub-scanning direction, and the first side surface is formed on the second side surface. A notch portion spaced from the side surface is provided. The covering member is provided on the notch, and the covering member provided on the notch is joined to the heat radiating plate, and the covering provided on the heat radiating plate is provided. A member is separated from the head base.

  A thermal printer according to an embodiment of the present invention includes the thermal head described above, 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. .

  The possibility of cracks occurring in the covering member can be reduced while improving the bonding strength of the wiring board.

It is a disassembled perspective view which shows the outline of the thermal head which concerns on 1st Embodiment. It is a top view which shows the thermal head shown in FIG. It is the II sectional view taken on the line shown in FIG. The thermal head which concerns on 1st Embodiment is shown, (a) is a top view which expands and shows a wiring board, (b) is the II-II sectional view taken on the line in FIG. 4 (a), (c) is FIG. It is the III-III sectional view taken on the line shown to (a). 1 is a schematic diagram illustrating a thermal printer according to a first embodiment. The thermal head which concerns on 2nd Embodiment is shown, (a) is a top view which expands and shows a wiring board, (b) is the IV-IV sectional view taken on the line shown to Fig.6 (a).

<First Embodiment>
Hereinafter, the thermal head X1 will be described with reference to FIGS. FIG. 1 schematically shows the configuration of the thermal head X1. In FIG. 2, the protective layer 25 and the covering layer 27 are omitted, and the covering member 29 is indicated by a one-dot chain line, and the wiring conductor 6b is not shown.

  The thermal head X1 includes a head substrate 3, a wiring board 6, a heat sink 1, an adhesive member 14, a conductive member 16, a covering member 29, a flexible wiring board 5 (hereinafter referred to as FPC 5), and a connector 31. And have. The head base 3 and the wiring board 6 are fixed to the heat sink 1 by an adhesive member 14. The drive IC 11 is provided on the wiring board 6 and is electrically connected to the head base 3 via the conductive member 16. The drive IC 11 is sealed with a covering member 29, and a part of the covering member 29 is disposed on the heat sink 1. The FPC 5 is electrically connected to the wiring board 6 and is electrically connected to the outside via the connector 31.

  The heat sink 1 has a flat plate shape, on which the head base 3 and the wiring board 6 are placed. The heat radiating plate 1 is made of, for example, a metal material such as copper, iron, or aluminum, and has a function of radiating heat that does not contribute to printing out of heat generated in the heat generating portion 9 of the head base 3. . Since the heat sink 1 is made of a metal material, the thermal expansion coefficient is about 9 to 11 ppm / ° C.

  The head base 3 is formed in a rectangular shape in plan view, and each member constituting the thermal head X1 is provided on the substrate 7 of the head base 3. The head substrate 3 has a function of printing on a recording medium (see FIG. 5) in accordance with an electric signal supplied from the outside.

  As shown in FIG. 3, the wiring board 6 includes a base material 6a, a wiring conductor 6b, and a cover member 6c. The wiring board 6 has a rectangular plate shape that is long in the main scanning direction, and the driving IC 11 is placed on the rectangular main surface. A conductive member 16 formed by a bonding wire is drawn out from the drive IC 11, and the conductive member 16 is electrically connected to the head base 3. Although not shown, a conductive member 16 is drawn from the drive IC 11 toward the wiring board 6 and is electrically connected to a wiring conductor 6 b provided on the wiring board 6.

  The wiring conductor 6b is patterned on the base material 6a, and electrically connects the FPC 5 and the head base 3 via the wiring conductor 6b. Examples of the wiring board 6 include a hard rigid board or PCB. Therefore, the wiring board 6 has a thermal expansion coefficient of about 18 to 20 ppm / ° C.

The FPC 5 includes a base material 5a, a wiring conductor 5b, and a cover member 5c. The base material 5a and the cover member 5c are formed of flexible flexible printed wiring boards, and the wiring conductor 5b is formed of a metal thin film. The connector 31 is electrically connected to the FPC 5 and electrically connects the FPC 5 and an external power source.

  As shown in FIG. 3, the wiring board 6 and the FPC 5 are joined by a joining member 23. Examples of the bonding member 23 include solder or an anisotropic conductive adhesive in which conductive particles are mixed in an electrically insulating resin. A plating layer (not shown) made of Ni, Au, or Pd may be provided between the bonding member 23 and the wiring conductor 5b.

  The adhesive member 14 is disposed on the heat radiating plate 1 and joins the head base 3 and the wiring board 6 to the heat radiating plate 1. Thereby, the head base 3, the wiring board 6, and the heat sink 1 are integrated. Examples of the adhesive member 14 include a double-sided tape or a resinous adhesive.

  The covering member 29 is provided so as to cover the drive IC 11 and is formed long in the main scanning direction. The covering member 29 is provided on the head base 3, the wiring board 6, and the heat radiating plate 1, protects the drive IC 11, and joins the head base 3, the wiring board 6, and the heat radiating plate 1. The covering member 29 can be formed of, for example, an epoxy thermosetting resin, an ultraviolet curable resin, or a visible light curable resin.

  Hereafter, each member which comprises the head base | substrate 3 is demonstrated using FIG.

  The board | substrate 7 is arrange | positioned on the heat sink 1, and has comprised the rectangular shape by planar view. Therefore, the substrate 7 has one long side 7a, the other long side 7b, one short side 7c, and the other short side 7d. The substrate 7 is formed of, for example, an electrically insulating material such as alumina ceramic or a semiconductor material such as single crystal silicon. Therefore, the substrate 7 has a thermal expansion coefficient of about 6 to 8 ppm / ° C., and the thermal expansion coefficient is smaller than that of the radiator plate 1.

  A heat storage layer 13 is provided on the substrate 7. The heat storage layer 13 includes a raised portion 13 a that protrudes upward from the substrate 7. The raised portion 13a is disposed so as to be adjacent to one long side 7a of the substrate 7, extends in a band shape along the arrangement direction of the plurality of heat generating portions 9, and has a substantially semi-elliptical cross section. Further, the raised portion 13a functions so as to favorably press the recording medium P to be printed (see FIG. 7) against the protective layer 25 formed on the heat generating portion 9. The raised portion 13a is preferably provided with a height from the substrate 7 of 15 to 90 μm.

  The heat storage layer 13 is made of glass having low thermal conductivity, and temporarily stores part of the heat generated in the heat generating portion 9. Therefore, the time required to raise the temperature of the heat generating part 9 can be shortened, and it functions to improve the thermal response characteristics of the thermal head X1. 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 known in the art, and baking it.

  The electric resistance layer 15 is provided on the upper surface of the substrate 7 and the upper surface of the heat storage layer 13, and various electrodes constituting the head substrate 3 are provided on the electric resistance layer 15. The electrical resistance layer 15 is patterned in the same shape as various electrodes constituting the head base 3, and has an exposed region where the electrical resistance layer 15 is exposed between the common electrode 17 and the individual electrode 19. Each exposed region constitutes the heat generating portion 9 and is arranged in a row on the raised portion 13a.

The plurality of heat generating portions 9 are illustrated in a simplified manner in FIG. 2 for convenience of explanation, but are arranged at a density of, for example, 100 dpi to 2400 dpi (dot per inch). 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 to the heat generating portion 9, the heat generating portion 9 generates heat due to Joule heat generation.

  The common electrode 17 includes a main wiring portion 17a, a sub wiring portion 17b, a lead portion 17c, and a connection portion 17d. The common electrode 17 electrically connects the plurality of heat generating portions 9 and the connector 31. The main wiring portion 17 a extends along one long side 7 a of the substrate 7. The sub wiring part 17b extends along one short side 7c and the other short side 7d of the substrate 7, respectively. The lead portion 17c extends individually from the main wiring portion 17a toward each heat generating portion 9. The connecting portion 17d is electrically connected to the conductive member 16 (FIG. 1).

  The plurality of individual electrodes 19 are electrically connected between the heat generating portion 9 and the drive IC 11. In addition, the individual electrode 19 divides the plurality of heat generating portions 9 into a plurality of groups, and electrically connects the heat generating portions 9 of each group and the drive IC 11 provided corresponding to each group. A pad 4 is provided at the end of the individual electrode 19. The pad 4 is electrically connected to the driving IC 11 disposed above via a bonding member 23.

  The plurality of IC-IC connection electrodes 26 electrically connect adjacent drive ICs 11. The plurality of IC-IC connection electrodes 26 are provided so as to correspond to the IC-connector connection electrodes 21, respectively, and transmit various signals to the adjacent drive ICs 11.

  For the various electrodes constituting the head substrate 3, for example, a material layer constituting each of the electrodes is sequentially laminated on the heat storage layer 13 by a conventionally well-known thin film forming technique such as a sputtering method, and then the laminate is conventionally known. It is formed by processing into a predetermined pattern using photoetching or the like. The various electrodes constituting the head base 3 can be formed simultaneously by the same process.

  As shown in FIG. 2, the drive IC 11 is arranged corresponding to each group of the plurality of heat generating units 9. As shown in FIG. 3, the drive IC 11 is electrically connected to the pad 4 of the individual electrode 19 via the conductive member 16, and is electrically connected to the wiring conductor 6 b via the conductive member 16. The drive IC 11 has a function of controlling the energization state of each heat generating unit 9. As the drive IC 11, a switching member having a plurality of switching elements inside may be used.

  As shown in FIG. 3, a protective layer 25 is formed on the heat storage layer 13 provided on the substrate 7 to cover the heat generating portion 9, a part of the common electrode 17 and a part of the individual electrode 19.

The protective layer 25 protects the area covered with the heat generating portion 9, the common electrode 17 and the individual electrode 19 from corrosion due to adhesion of moisture or the like contained in the atmosphere, or wear due to contact with the recording medium to be printed. belongs to. The protective layer 25 can be formed using SiN, SiO ₂ , SiON, SiC, diamond-like carbon, or the like, and the protective layer 25 may be formed of a single layer or may be formed by stacking these layers. May be. Such a protective layer 25 can be produced using a thin film forming technique such as sputtering or a thick film forming technique such as screen printing.

  As shown in FIG. 3, a covering layer 27 that partially covers the protective layer 25 and the individual electrodes 19 is provided on the substrate 7. The covering layer 27 has a function of protecting the covered region from oxidation due to contact with the atmosphere or corrosion due to adhesion of moisture or the like contained in the atmosphere.

With reference to FIG. 4, the bonding of the wiring substrate 6, the head base 3, and the heat sink 1 will be described. 4 shows the heat radiating plate 1, the adhesive member 14, the substrate 7, the wiring substrate 6, and the covering member 29, and other members are omitted. In addition, in the wiring board 6, the configurations of the base material 6a, the wiring conductor 6b, and the cover member 6c are omitted. Further, in FIG. 4A, the covering member 29 is indicated by spots for easy understanding.

  The substrate 7 and the wiring substrate 6 are bonded onto the heat sink 1 by an adhesive member 14. The substrate 7 and the wiring substrate 6 are arranged side by side in the sub-scanning direction and are formed long in the main scanning direction. The length of the substrate 7 in the main scanning direction is configured to be longer than the length of the wiring substrate 6 in the main scanning direction, and a part of the other long side 7c of the substrate 7 and the other short side 7d are It is exposed from the covering member 29.

  The wiring board 6 has a rectangular main surface, and has a first side surface 6d along the main scanning direction and a second side surface 6e along the sub-scanning direction. The first side surface 6 d is disposed so as to face the other long side 7 c of the substrate 7.

  The second side surface 6e has a straight line part 6f and a notch part 6g. The straight line portion 6f connects the notch portion 6g and the first side surface 6d, and is formed to extend in the sub-scanning direction. The cutout portion 6g is formed so as to cut out a part of the second side surface 6e, and has a semicircular shape in plan view. The notch 6g is provided in a state of being separated from the first side surface 6d.

  The covering member 29 is provided so as to cover the wire (see FIG. 1), and is formed on the substrate 7 and the wiring substrate 6. As shown in FIG. 4B, a part of the covering member 29 arranged on the wiring board 6 flows into the notch 6g and flows out as a fluid covering member 29a onto the heat sink 1 through the notch 6g. Yes. Thereby, the flow coating member 29a is in contact with the heat sink 1 and the wiring board 6 can be bonded to the heat sink 1 by the flow cover member 29a in addition to the adhesive member 14, and the bonding strength of the wiring board 6 is improved. Can be made.

  Here, the heat radiating plate 1 has a thermal expansion coefficient larger than that of the substrate 7, and there is a problem that stress is concentrated on the side surface of the substrate 7 due to a temperature cycle at the time of manufacturing or driving the thermal head X 1. In particular, when the substrate 7 is formed long in the main scanning direction, a large stress is applied to the side surfaces of both ends in the main scanning direction, that is, the side surface constituting the other long side 7c and the side surface constituting the other long side 7d. Will occur. Therefore, when the covering member 29 is disposed in the space 8 adjacent to the side surface of the substrate 7, stress concentrates on the covering member 29, and there is a possibility that the covering member 29 may crack.

  In contrast, the wiring board 6 has a notch 6g spaced from the first side face 6d, and a part of the covering member 29 provided on the wiring board 6 is notched due to the capillary action of the notch 6g. A flow coating member 29 a provided on 6 g and provided on the notch 6 g is joined to the heat sink 1. Therefore, the bonding strength of the wiring board 6 can be improved, the inflow of the covering member 29 into the space 8 on the substrate 7 side can be reduced, and the stress concentration on the covering member 29 can be reduced. As a result, it is possible to reduce the occurrence of cracks in the covering member 29 while improving the bonding strength of the covering member 29.

  In addition, the fluid covering member 29a provided on the notch 6g and the heat radiating plate 1 are joined together means that the fluid covering member 29a and the heat radiating plate 1 are joined via the adhesive member 14. Contains.

The second side surface 6e of the wiring substrate 6 is provided with a straight portion 6f between the notch 6g and the substrate 7 in plan view. The straight line portion 6f is a cross line between the second side surface 6e of the wiring board 6 and the main surface, and is a corner portion. Therefore, as shown in FIG. 4C, when the covering member 29 provided on the wiring board 6 is about to flow from the wiring board 6 to the space 8 side on the board 7, the straight portion 6f.
The surface tension works on the top, and the weir is stopped on the straight portion 6f. Therefore, the covering member 29 can be hardly provided in the space 8 on the substrate 7 side.

  That is, when the covering member 29 flows in the main scanning direction and reaches the straight portion 6f, the covering member 29 has lower wettability than the wiring substrate 6 because the wiring substrate 6 is not provided after the straight portion 6f. The structure is surrounded by air. As a result, surface tension acts on the covering member 29, and it is difficult for the covering member 29 to flow from the wiring substrate 6 to the space 8 on the substrate 7. Therefore, the covering member 29 can be dammed by the straight portion 6f.

  The length of the straight portion 6f in the sub-scanning direction is longer than the distance between the notch 6g and the substrate 7 as shown in FIG. Therefore, even if the flow coating member 29a is arranged on the heat sink 1 by the notch 6g, there is a sufficient distance from the substrate 7 and it is difficult to flow into the space 8 on the substrate 7 side. As a result, it is possible to reduce the occurrence of cracks in the covering member 29 while improving the bonding strength of the covering member 29.

  The length of the straight portion 6f in the sub-scanning direction can be set to, for example, 0.3 to 1.5 mm, and the distance between the cutout portion 6g and the substrate 7 can be set to, for example, 0.3 to 1.5 mm. Can do. Further, when the length of the substrate 7 in the sub-scanning direction is 0.3 to 1.0 mm, the length of the covering member 29 in the sub-scanning direction can be set to 1.5 to 3.5 mm, for example.

  The joining of the wiring board 6 of the thermal head X1, the head base 3, and the heat sink 1 will be described.

  First, a notch 6g is formed on the second side surface 6e of the wiring board 6 on which the driving IC 11 (see FIG. 1) is mounted by a drill or the like. Next, the adhesive member 14 is joined to the heat sink 1. Next, the substrate 7 and the wiring substrate 6 are placed on the adhesive member 14. At this time, the side surface formed by the other long side 7 c of the substrate 7 and the first side surface 6 d of the wiring substrate 6 are placed facing each other.

  Next, the covering member 29 is applied by a dispenser so as to cover the conductive member 16 (see FIG. 1). The covering member 29 is formed by applying resin while moving the head of the dispenser in the main scanning direction. The head of the dispenser increases the amount of the covering member to be applied in the vicinity of the second side surface 6e so that the covering member is provided in the notch 6g. A part of the coated covering member 29 is guided to the notch 6g by a capillary phenomenon, and a fluid covering member 29a is formed on the heat radiating plate 1. Subsequently, the covering member 29 can be dried and cured to join the wiring substrate 6, the head base 3, and the heat sink 1.

  Next, the thermal printer Z1 will be described with reference to FIG.

  As shown in FIG. 5, the thermal printer Z <b> 1 of the present embodiment includes the above-described thermal head X <b> 1, a transport mechanism 40, a platen roller 50, a power supply device 60, and a control device 70. The thermal head X1 is attached to an attachment surface 80a of an attachment member 80 provided in a housing (not shown) of the thermal printer Z1. The thermal head X1 is attached to the attachment member 80 so as to be along a main scanning direction which is a direction orthogonal to the conveyance direction S of the recording medium P described later.

The transport mechanism 40 includes a drive unit (not shown) and transport rollers 43, 45, 47, and 49. 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. 5 and on the protective layer 25 positioned on the plurality of heat generating portions 9 of the thermal head X1. It is for carrying. The drive unit has a function of driving the transport rollers 43, 45, 47, and 49, and for example, a motor can be used. Conveyance rollers 43, 45, 47,
49 can be constituted by, for example, covering cylindrical shaft bodies 43a, 45a, 47a, 49a made of metal such as stainless steel with elastic members 43b, 45b, 47b, 49b made of butadiene rubber or the like. Although not shown, when the recording medium P is an image receiving paper or the like 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 X1.

  The platen roller 50 has a function of pressing the recording medium P onto the protective film 25 located on the heat generating portion 9 of the thermal head X1. The platen roller 50 is disposed so as to extend along a direction orthogonal to the conveyance direction S of the recording medium P, and both ends thereof are supported and fixed so as to be rotatable while the recording medium P is pressed onto the heat generating portion 9. ing. 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 has a function of supplying a current for generating heat from the heat generating portion 9 of the thermal head X1 and a current for operating the drive IC 11 as described above. The control device 70 has a function of supplying a control signal for controlling the operation of the drive IC 11 to the drive IC 11 in order to selectively heat the heat generating portion 9 of the thermal head X1 as described above.

  The thermal printer Z1 presses the recording medium P onto the heat generating portion 9 of the thermal head X1 by the platen roller 50, and conveys the recording medium P onto the heat generating portion 9 by the transport mechanism 40, while the power supply device 60 and the control device 70. As a result, the heating section 9 is selectively heated to perform predetermined printing on the recording medium P. When the recording medium P is an image receiving paper or the like, printing is performed on the recording medium P by thermally transferring ink of an ink film (not shown) conveyed together with the recording medium P to the recording medium P.

<Second Embodiment>
The thermal head X2 will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the member same as thermal head X1, and it is the same below. 6 shows the heat radiating plate 1, the adhesive member 14, the substrate 7, the wiring substrate 106, and the covering member 129 as in FIG. 4, and other members are omitted. . Similarly to FIG. 4, in FIG. 6A, the covering member 129 is indicated by spots.

  The wiring board 106 is formed of a base material 106a, a wiring conductor 106b, and a cover member 106c, and includes a first side face 106d, a second side face 106e, and a recess 110 formed on the main surface. Yes.

  The first side surface 106 d is disposed so as to face the side surface formed by the other long side 7 c of the substrate 7. The second side surface 106e has a straight line part 106f and a notch part 106g.

  The recess 110 is provided on the main surface of the wiring substrate 106 in a state of being separated from the first side surface 106d and the second side surface 106e, and is provided so that the upper surface of the wiring substrate 106 is recessed. Therefore, the edge of the recessed part 110 is spaced apart from the first side face 106d and the second side face 106e. The recess 110 is formed by notching the cover member 106 c, and the base material 106 a and the wiring conductor 112 are exposed in the recess 110.

The wiring substrate 106 has a recess 110 that is spaced from the second side surface 106 e, and the distance between the recess 110 and the substrate 7 is shorter than the distance between the notch 106 g and the substrate 7. Therefore, when the covering member 129 provided on the wiring board 106 tries to flow from the wiring board 106 to the space 8 side on the board 7, surface tension acts on the edge of the recess 110, and FIG. ), The dams are dammed on the edge of the recess 110. Therefore, the inflow of the covering member 129 into the space 8 on the substrate 7 side can be reduced.

  Even when the coating amount of the covering member 129 provided on the wiring substrate 106 is large, the covering member 129 can be accommodated in the recess 110, and the surplus covering member 129 can be accommodated in the space 8 on the substrate 7 side. Can be reduced.

  Furthermore, if there is an excess covering member 129 on the surface of the wiring board 106, the height of the covering member 129 increases, and there is a possibility that it will come into contact with the recording medium P (see FIG. 5). By accommodating the covering member 129, the height of the covering member 129 can be reduced. As a result, the possibility that the covering member 129 contacts the recording medium P can be reduced.

  Further, since the distance between the edge of the recess 110 and the substrate 7 is configured to be shorter than the distance between the notch 106g and the substrate 7, the covering member 129 dammed up on the edge of the recess 110 has the notch 106g. It will be easy to leak. As a result, the flow coating member 129a spreads on the heat sink 1 from the notch 106g, and the bonding strength of the wiring board 106 can be improved.

  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. For example, although the thermal printer Z1 using the thermal head X1 according to the first embodiment is shown, the present invention is not limited to this, and the thermal head X2 may be used for the thermal printer Z1.

  For example, the thin film head of the heat generating portion 9 is illustrated by forming the electric resistance layer 15 as a thin film. However, the present invention is not limited to this. The present invention may be used for a thick film head of the heat generating portion 9 by forming a thick film of the electric resistance layer 15 after patterning various electrodes.

  Further, the planar head in which the heat generating portion 9 is formed on the substrate 7 has been described as an example, but the present invention may be used for an end face head in which the heat generating portion 9 is provided on the end surface of the substrate 7.

  Further, the heat storage layer 13 may form a base portion in a region other than the raised portion 13a. Even if the heat generating portion 9 is formed by forming the common electrode 17 and the individual electrode 19 on the heat storage layer 13 and forming the electric resistance layer 15 only in the region between the common electrode 17 and the individual electrode 19. Good.

X1 to X2 Thermal head Z1 Thermal printer 1 Heat sink 3 Head base 5 Flexible wiring board 6,106 Wiring board 6a, 106a Base material 6b, 106b Wiring conductor 6c, 106c Cover member 6d, 106d First side face 6e, 106e Second side face 6f, 106f linear part 6g, 106g notch part 7 substrate 9 heating part 11 drive IC
DESCRIPTION OF SYMBOLS 13 Heat storage layer 14 Adhesive member 16 Conductive member 17 Common electrode 19 Individual electrode 23 Joining member 29,129 Cover member 29a, 129a Flow coating member 31 Connector 40 Conveying mechanism 50 Platen roller

Claims (5)

A substrate, a heat generating portion provided on the substrate, and a head base having an electrode provided on the substrate and electrically connected to the heat generating portion;
A wiring board having a wiring conductor electrically connected to the electrode;
A heat sink disposed below the head base and the wiring board;
A conductive member for electrically connecting the electrode and the wiring conductor;
Covering the conductive member, and a covering member provided on a part of the substrate and a part of the wiring board,
The wiring board has a rectangular main surface, and has a first side surface extending in the main scanning direction and a second side surface extending in the sub-scanning direction, and the first side surface is formed on the second side surface. A spaced apart notch is provided,
The covering member is provided on the notch, and the covering member provided on the notch is joined to the heat sink,
The thermal head, wherein the covering member provided on the heat radiating plate is separated from the head base.   The thermal head according to claim 1, wherein the second side surface is provided with a linear portion between the cutout portion and the substrate in plan view.   The thermal head according to claim 2, wherein a length of the linear portion is longer than a length of the notch portion. The main surface of the wiring board has a recess spaced from the second side surface,
The thermal head according to any one of claims 1 to 3, wherein a distance between the recess and the substrate is shorter than a distance between the notch and the substrate. The thermal head according to any one of claims 1 to 4,
A transport mechanism for transporting a recording medium onto the heat generating unit;
A thermal printer comprising: a platen roller that presses the recording medium onto the heat generating portion.

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