JP2016203526A - Thermal head and thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal head which hardly causes a short-circuit due to crushing of solder.SOLUTION: A thermal head X1 comprises: a substrate; a plurality of heating parts which are provided on the substrate; a plurality of drive ICs 11 which control driving of the heating parts and have first connection terminals 18 and second connection terminals 20; a plurality of first electrodes 19 which electrically connect the plurality of heating parts and the plurality of drive ICs 11; a plurality of pieces of first plating 14 which are provided on the plurality of the first electrodes 19; a plurality of pieces of first solder which electrically connect the first plating 14 and the first connection terminals 18; a second electrode 4 which is electrically connected in common to the plurality of drive ICs; a plurality of pieces of second plating 16 which are provided on the second electrode 4; and a plurality of pieces of second solder which electrically connect the second plating 16 and the second connection terminals 20. Since the area of the second plating 16 is larger than the area of the first plating 14 in a plan view, the possibility that a short-circuit occurs in the thermal head X1 can be reduced.SELECTED DRAWING: Figure 5

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 plurality of heat generating portions provided on the substrate, a plurality of drive ICs for controlling driving of the heat generating portions, a plurality of heat generating portions and a plurality of drive ICs each electrically connected to each other A thermal head including one electrode and a second electrode electrically connected in common with a plurality of driving ICs is known (see, for example, Patent Document 1).

  Further, there is known a thermal head in which the driving IC has a plurality of first solders and second solders, and the driving IC is connected to the first electrode and the second electrode by flip chip connection (for example, patents). Reference 2).

JP-A-9-39284 JP 2014-87938 A

  However, in the thermal head described above, when the driving IC is mounted, the second solder is crushed, so that the second solder that has flowed out may contact the first electrode and short-circuit.

  A thermal head according to an embodiment of the present invention includes a substrate, a plurality of heat generating units provided on the substrate, and a plurality of heat generating units that control driving of the heat generating unit and have a first connection terminal and a second connection terminal. A plurality of first electrodes electrically connecting the driving IC, the plurality of heat generating units and the plurality of driving ICs, a plurality of first platings provided on the plurality of first electrodes, and the first A plurality of first solders that electrically connect the plating and the first connection terminals, a second electrode that is electrically connected in common with the plurality of drive ICs, and a plurality that is provided on the second electrode Second plating and a plurality of second solders for electrically connecting the second plating and the second connection terminals. Also, in plan view, the area of the second plating is larger than the area of the first plating.

  A thermal head according to an embodiment of the present invention includes a substrate, a plurality of heat generating units provided on the substrate, and a plurality of heat generating units that control driving of the heat generating unit and have a first connection terminal and a second connection terminal. A plurality of first electrodes electrically connecting the driving IC, the plurality of heat generating units and the plurality of driving ICs, a plurality of first platings provided on the plurality of first electrodes, and the first A plurality of first solders that electrically connect the plating and the first connection terminals, a second electrode that is electrically connected in common with the plurality of drive ICs, and a plurality that is provided on the second electrode Second plating and a plurality of second solders for electrically connecting the second plating and the second connection terminals. Further, the second plating is disposed on a side farther than the second connection terminal with respect to the first electrode in plan view.

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. .

  According to the present invention, the possibility of a short circuit occurring in the thermal head can be reduced.

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 outline of the thermal head shown in FIG. It is the II sectional view taken on the line shown in FIG. FIG. 2 is an enlarged view of the vicinity of a connector constituting the thermal head according to the first embodiment, wherein (a) is a top view and (b) is a bottom view. FIG. 2 is an enlarged view of a part of the thermal head according to the first embodiment, wherein (a) is a plan view showing a plating pattern, and (b) is a plan view showing a state where an IC is mounted. (A) is the II-II sectional view taken on the line shown in FIG.5 (b), (b) is the III-III sectional view taken on the line shown in FIG.5 (b). 1 is a schematic diagram illustrating a thermal printer according to a first embodiment. The thermal head which concerns on 2nd Embodiment is partially expanded and shown, (a) is a top view in the state which mounted IC, (b) is the IV-IV sectional view taken on the line shown to Fig.8 (a) It is. The thermal head which concerns on 3rd Embodiment is partially expanded and shown, (a) is a top view which shows a plating pattern, (b) is a top view in the state which mounted IC. (A) is the VV sectional view taken on the line shown in FIG.9 (b), (b) is the VI-VI sectional view taken on the line in FIG.9 (b).

<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. FIG. 2 schematically shows the shapes of various electrodes, and the protective layer 25, the covering layer 27, and the sealing member 12 are indicated by a one-dot chain line. Moreover, in FIG. 4, the area | region where the sealing member 12 is provided is shown with the spot. In FIG. 6B, the first connection terminal and the second connection terminal are shown by solid lines for easy understanding.

  The thermal head X <b> 1 includes a head base 3, a connector 31, a sealing member 12, a heat radiating plate 1, and an adhesive member 28. In the thermal head X 1, the head base 3 is placed on the heat radiating plate 1 via an adhesive member 28. The head base 3 heats the heat generating portion 9 when an external voltage is applied to print on a recording medium (not shown). The connector 31 electrically connects the outside and the head base 3. The sealing member 12 joins the connector 31 and the head base 3. The heat radiating plate 1 is provided to radiate the heat of the head base 3. The adhesive member 28 bonds the head base 3 and the heat sink 1.

  The heat sink 1 has a rectangular parallelepiped shape, and the substrate 7 is placed on the upper surface. 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. .

  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 base 3 has a function of printing on a recording medium (not shown) in accordance with an electric signal supplied from the outside.

The connector 31 includes a plurality of connector pins 8 and a housing 10 that houses the plurality of connector pins 8. The plurality of connector pins 8 are provided so as to sandwich the upper surface and the lower surface of the head base 3 and are covered by the sealing member 12 so that the connector pins 8 are not exposed.

  The connector 31 and the head base 3 are electrically connected by a conductive bonding material 23 (see FIG. 3). Examples of the conductive bonding material 23 include solder or an anisotropic conductive adhesive in which conductive particles are mixed in an electrically insulating resin. Note that the conductive bonding material 23 is not necessarily provided. In this case, the electrode of the head base 3 and the connector pin 8 may be directly electrically connected by holding the substrate 7 with the connector pin 8 using the clip-type connector pin 8.

  The adhesive member 28 is disposed on the upper surface of the radiator 1 and joins the head base 3 and the radiator plate 1 together. Examples of the adhesive member 28 include a double-sided tape or a resinous adhesive.

  Hereinafter, each member constituting the head base 3 will be described.

  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.

  A heat storage layer 13 is provided on the upper surface of 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 extends in a strip 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 main wiring portions 17a and 17d, a sub wiring portion 17b, and a lead portion 17c. 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. Main wiring part 17
d extends along the other long side 7 b of the substrate 7.

  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.

  The individual electrode 19 has one end connected to the heat generating portion 9 and the other end extending to the lower side of the driving IC 11, and on the individual electrode 19 positioned below the driving IC 11 as shown in FIG. The 1st plating 14 is provided in this. The other end of the drive IC 11 is alternately shifted in the sub-scanning direction.

  The plurality of IC-connector connection electrodes 21 electrically connect the drive IC 11 and the connector 31. The plurality of IC-connector connection electrodes 21 connected to each drive IC 11 are composed of a plurality of wirings having different functions, and have a ground electrode 4 and a signal electrode 6.

  The ground electrode 4 is disposed so as to be surrounded by the individual electrode 19, the IC-connector connection electrode 21, and the main wiring portion 17 d of the common electrode 17. The ground electrode 4 is provided extending in the main scanning direction, and is electrically connected in common to the plurality of driving ICs 11. The ground electrode 4 is held at a ground potential of 0 to 1V.

  The signal electrode 6 is disposed between the individual electrode 19 and the ground electrode 4, and is provided so as to surround the ground electrode 4. The signal electrode 6 extends below the drive IC 11 in the main scanning direction, and is electrically connected to the plurality of drive ICs 11 in common.

  The connection terminal 2 is provided on the other long side 7 b side of the substrate 7 in order to connect the common electrode 17, the individual electrode 19, and the IC-connector connection electrode 21 to the connector 31. The connection terminal 2 is provided corresponding to the connector pin 8, and when connecting to the connector 31, the connector pin 8 and the connection terminal 2 are connected so as to be electrically independent from each other.

  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 disposed corresponding to each group of the plurality of heat generating units 9 and is connected to the other end of the individual electrode 19 and one end of the IC-connector connection electrode 21. ing. 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.

  The drive IC 11 is sealed with a hard coat 29 made of an epoxy resin or a resin such as a silicone resin while being connected to the individual electrode 19, the IC-IC connection electrode 26 and the IC-connector connection electrode 21.

As shown in FIGS. 2 and 3, a protective layer 25 that covers the heat generating portion 9, a part of the common electrode 17 and a part of the individual electrode 19 is formed on the heat storage layer 13.

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 FIGS. 2 and 3, a covering layer 27 that partially covers the common electrode 17, the individual electrode 19, and the IC-connector connection electrode 21 is provided on the substrate 7. The covering layer 27 is formed by oxidizing the region covered with the common electrode 17, the individual electrode 19, the IC-IC connection electrode 26, and the IC-connector connection electrode 21 by contact with the atmosphere or moisture contained in the atmosphere. It is intended to protect against corrosion due to adhesion.

  The sealing member 12 has a first sealing member 12a and a second sealing member 12b. The first sealing member 12 a is located on the upper surface of the substrate 7, and the second sealing member 12 b is located on the lower surface of the substrate 7. The first sealing member 12 a is provided so as to seal the connector pin 8 and various electrodes, and the second sealing member 12 b is provided so as to seal the connector pin 8.

  The sealing member 12 is provided so that the connection terminals 2 and the connector pins 8 are not exposed to the outside. For example, an epoxy-based thermosetting resin, an ultraviolet curable resin, or a visible light curable resin is used. Can be formed. In addition, the 1st sealing member 12a and the 2nd sealing member 12b may be formed with the same material, and may be formed with another material.

  The electrical connection between the head base 3 and the drive IC 11 will be described in detail with reference to FIGS.

  The head base 3 and the drive IC 11 are such that the first plating 14 of the head base 3 and the first connection terminal 18 of the drive IC 11 are electrically connected by the first solder 22, and the second plating 16 of the head base 3. And the second connection terminal 20 of the driving IC 11 are electrically connected by the second solder 22.

  The first plating 14 is provided on the individual electrode 19 and has a first plating row 14a and a second plating row 14b. The 1st plating row | line | column 14a is comprised by the 1st plating 14c, and is arranged in the main scanning direction. The second plating row 14b is composed of the first plating 14d, and is arranged in the main scanning direction. The first plating row 14a and the second plating row 14b are arranged so as to be adjacent to each other in the sub-scanning direction, and the second plating row 14b is arranged between the first plating row 14a and the ground electrode 4. .

  The first plating 14 has a rectangular shape that is long in the sub-scanning direction when viewed from above, and is formed so as not to reach the edge of the individual electrode 19. Thereby, the possibility that the adjacent individual electrodes 19 are short-circuited by the first solder 20 can be reduced.

  The length of the first plating 14 in the sub-scanning direction can be, for example, 0.095 μm to 0.115 μm, and the length of the first plating 14 in the main scanning direction is, for example, 0.055 μm to 0.075 μm. It can be. The first plating 14c constituting the first plating row 14a and the first plating 14d constituting the second plating row 14b are formed in the same shape.

  The second plating 16 is provided on the ground electrode 4 and arranged in the main scanning direction. The second plating 16 is arranged in the main scanning direction and is formed so as to cover the edge of the ground electrode 4. The second plating 16 has a rectangular shape that is long in the main scanning direction.

  The length of the second plating 16 in the main scanning direction can be, for example, 0.095 μm to 0.11 μm, and the length of the second plating 16 in the sub-scanning direction is, for example, 0.06 μm to 0.08 μm. It can be. Therefore, the thermal head X1 is configured such that the area of the second plating 16 is larger than the area of the first plating 14 when viewed in plan.

  When the individual electrode 19 is formed of Al, the first plating 14 and the second plating 16 can be formed of, for example, Au.

  The drive IC 11 has a first connection terminal 18 and a second connection terminal 20 on the lower surface. A plurality of first connection terminals 18 are arranged along the main scanning direction on one long side 11 a side of the drive IC 11, and the second connection terminals 20 are main-scanned on the other long side 11 b side of the drive IC 11. A plurality are arranged along the direction.

  The first connection terminals 18 are provided so as to correspond to the first plating 14 and are provided in two rows adjacent to each other in the sub-scanning direction. The second connection terminal 20 is provided so as to correspond to the second plating 16.

  The first solder 22 is disposed between the first plating 14 and the first connection terminal 18 and electrically connects the individual electrode 19 and the drive IC 11. The second solder 24 is disposed between the second plating 16 and the second connection terminal 20 and electrically connects the ground electrode 4 and the drive IC 11. The first solder 22 and the second solder 24 are Sn-Pb material, Sn-Ag material, Sn-Cu material, or Sn-Ag- when the first plating 14 and the second plating 16 are made of Au. It can be formed of a Cu-based material.

  Here, in the thermal head X1, the driving IC 11 in which the first solder 22 is formed on the first connection terminal 18 and the second solder 24 is formed on the second connection terminal 20 is mounted on the head base 3, and the first solder is mounted. The driving IC 11 is mounted on the head base 3 by reflowing the 22 and the second solder 24 simultaneously.

  When the first solder 22 and the second solder 24 are reflowed, wettability differs depending on the individual electrode 19 and the ground electrode 4 provided below. That is, since the second solder 24 is commonly connected to the ground electrode 4, heat during reflow is transferred through the ground electrode 4, so that the rate of temperature rise is faster than that of the first solder 22. Therefore, the second solder 24 has higher wettability with respect to the first solder 20 due to a shorter zero cross time until reflow. Therefore, the second solder 24 may be crushed by the weight of the drive IC 11 when the drive IC 11 is mounted, and the crushed second solder 24 may contact the signal electrode 6 or the individual electrode 19 and may be short-circuited.

  On the other hand, in the thermal head X1, since the area of the second plating 16 is larger than the area of the first plating 14 in plan view, the second solder 24 collapsed even when the second solder 24 is collapsed. The solder 24 spreads on the second plating 16 having a large area. As a result, the possibility that the crushed second solder 24 contacts the signal electrode 6 or the individual electrode 19 can be reduced, and the possibility that a short circuit occurs in the thermal head X1 can be reduced.

In the thermal head X1, the second plating 16 is formed long in the main scanning direction. That is, the length of the second plating 16 in the main scanning direction is longer than the length of the second plating 16 in the sub-scanning direction.

  As a result, the crushed second solder 24 easily flows in the main scanning direction and hardly flows in the sub-scanning direction. As a result, the possibility that the crushed second solder 24 contacts the signal electrode 6 or the individual electrode 19 can be reduced, and the possibility that a short circuit occurs in the thermal head X1 can be reduced.

  In the thermal head X1, the first plating 14 is formed long in the sub-scanning direction. That is, the length of the first plating 14 in the sub-scanning direction is longer than the length of the first plating 14 in the main scanning direction.

  Thereby, the length of the individual electrodes 19 in the main scanning direction can be shortened without reducing the planar view area of the first plating 14, and the wiring pitch of the individual electrodes 19 can be shortened. Thereby, the wiring of the individual electrode 19 can be made dense, and the high-definition thermal head X1 can be provided.

  Further, in the thermal head X1, it is preferable that the area of the second plating 16 is 1.1 to 5.0 times the area of the first plating 14 in plan view. Thereby, the possibility that the crushed second plating 16 contacts the signal electrode 6 or the individual electrode 19 can be reduced.

  In the thermal head X1, it is preferable that the area center of gravity of the first connection terminal 18 overlaps the area center of gravity of the first plating 14 in plan view. In addition, it is preferable that the thermal head X1 has the area centroid of the second connection terminal 20 overlapped with the area centroid of the second plating 16 in plan view. Thereby, the center of gravity of the first solder 22 and the second solder 24 melted at the time of reflow is respectively the area center of gravity of the first connection terminal 18 and the first plating 14 and the area center of gravity of the second connection terminal 20 and the second plating 16. As a result, the first solder 22 and the second solder 24 are not easily stressed. As a result, the first solder 22 and the second solder 24 can be easily retained on the first plating 14 and the second plating 16.

  Although the example in which the first plating 14 and the second plating 16 are formed in a rectangular shape has been shown, the first plating 14 and the second plating 16 have other shapes such as a trapezoidal shape, a circular shape, or an elliptical shape. It may be.

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

  As shown in FIG. 7, 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. 7 and is placed 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. The transport rollers 43, 45, 47, and 49 are formed by, for example, covering 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 or the like. Can be configured. 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.

  As shown in FIG. 7, the thermal printer Z1 presses the recording medium P onto the heat generating part 9 of the thermal head X1 by the platen roller 50, and conveys the recording medium P onto the heat generating part 9 by the conveying mechanism 40. The heat generating unit 9 is selectively heated by the power supply device 60 and the control device 70 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. In the thermal head X2, the shape and arrangement of the second plating 116 and the shape of the second solder 124 are different from the shape and arrangement of the second plating 16 of the thermal head X1 and the shape of the second solder 24. Other configurations are the same as those of the thermal head X1, and the description thereof is omitted.

  A plurality of second platings 116 are arranged in the main scanning direction and are formed long in the main scanning direction. The second plating 116 is not formed on the edge 4a of the ground electrode 4, but is disposed apart from the edge 4a. The second plating 116 is disposed on the side farther than the second connection terminal 20 with respect to the individual electrode 19. That is, the second plating 116 is disposed on the other long side 11 b side of the drive IC 11 with respect to the second connection terminal 20.

  Therefore, the thermal head X2 has a configuration in which the distance between the second plating 116, the signal wiring 6, and the individual electrode 19 is long. As a result, even when the second solder 124 is crushed, the distance between the crushed second solder 124 and the signal wiring 6 and the individual electrode 19 becomes long, and the crushed second solder 124 becomes the signal wiring 6 and the individual electrode 19. The possibility of touching 19 can be reduced.

  Further, since the second plating 116 is formed long in the main scanning direction, even when the second solder 124 is crushed, the crushed second solder 124 is easy to flow in the main scanning direction. 6 and the possibility of contact with the individual electrode 19 can be reduced.

In the thermal head X2, the example in which the area of the first plating 14 and the area of the second plating 116 when viewed in plan is approximately the same is shown, but the present invention is not limited to this. For example, the second plating 116 is disposed on the side farther than the second connection terminal 20 with respect to the individual electrode 19, and the area of the second plating 116 is the area of the first plating 14 when planarized. A larger configuration may be used. In that case, the possibility that the crushed second solder 124 contacts the signal wiring 6 and the individual electrode 19 can be further reduced.

<Third Embodiment>
A thermal head X3 according to the third embodiment will be described with reference to FIGS. The thermal head X3 is different from the thermal head X2 in the first plating 214, the second plating 216, the first solder 222, and the second solder 224, and the other configurations are the same.

  In the individual electrode 19, the portion where the second plating row 214 b is formed is disposed closer to the signal electrode 6 than the portion where the first plating row 214 a is formed, and the individual electrode 19 is a portion of the portion where the first plating row 214 a is formed. It has a constricted portion 19a in between.

  The first plating 214 has a first plating row 214a and a second plating row 214b, the first plating row 214a is constituted by the first plating 214c, and the second plating row 214b is the first plating 214d. It is comprised by. The length of the first plating 214d constituting the second plating row 214b in the sub-scanning direction is shorter than the length of the first plating 214c constituting the first plating row 214a in the sub-scanning direction.

  As a result, the possibility that the first plating 214d constituting the second plating row 214b is formed up to the constricted portion 19a of the individual electrode 19 can be reduced. Therefore, it can suppress that the 1st solder 222 is formed on the constriction part 19a, and can reduce possibility that the 1st solder 22 provided on the adjacent individual electrode 19 will contact. . Therefore, the possibility that the thermal head X3 is short-circuited can be reduced.

  The length of the first plating 214c constituting the first plating row 214a in the sub-scanning direction can be, for example, 0.11 μm to 0.13 μm, and the length in the main scanning direction can be, for example, 0.06 μm to It can be 0.07 μm.

  The length in the sub-scanning direction of the first plating 214d constituting the second plating row 214b can be, for example, 0.1 μm to 0.12 μm, and the length in the main scanning direction is, for example, 0.05 μm 5 It can be set to 0.075 μm.

  The length of the second plating 216 in the main scanning direction can be, for example, 0.07 μm to 0.95 μm, and the length of the second plating 16 in the sub scanning direction is, for example, 0.02 μm to 0.05 μm. It can be.

  The second plating 216 is provided on the ground electrode 4, and the planar view area of the second plating 216 is smaller than the planar view area of the first plating 214. More specifically, the planar view area of the second plating 216 is smaller than the planar view area of the first plating 214d constituting the second plating row 214b.

  The length of the first plating 214c constituting the first plating row 214a in the sub-scanning direction can be, for example, 0.11 μm to 0.13 μm, and the length in the main scanning direction can be, for example, 0.06 μm to It can be 0.07 μm.

  The length in the sub-scanning direction of the first plating 214d constituting the second plating row 214b can be, for example, 0.1 μm to 0.12 μm, and the length in the main scanning direction is, for example, 0.055 μm to It can be set to 0.075 μm.

The length of the second plating 216 in the main scanning direction can be, for example, 0.07 μm to 0.95 μm, and the length of the second plating 16 in the sub scanning direction is, for example, 0.02 μm to 0.05 μm.
m.

  Here, the second solder 224 provided on the second plating 216 has higher wettability than the first solder 222 provided on the first plating 214, and the second solder 224 may be crushed. For this reason, the height of the second solder 224 may be lower than the height of the first solder 222, and the drive IC 11 may be inclined.

  On the other hand, the thermal head X3 is configured such that the second solder 224 is difficult to spread because the area of the second plating 216 in plan view is smaller than the area of the first plating 214 in plan view. As a result, the second solder 224 is not easily crushed, and the possibility that the height of the second solder 224 is lower than the height of the first solder 222 can be reduced. Therefore, the possibility that the drive IC 11 is inclined can be reduced.

  Further, in the thermal head X <b> 3, the second plating 216 is disposed on the side farther than the second connection terminal 20 with respect to the individual electrode 19. Therefore, the possibility that the second solder 224 contacts the signal electrode 6 and the ground electrode 4 can be reduced, and the possibility that a short circuit occurs in the thermal head X3 can be reduced.

  Further, the first plating 214c constituting the first plating row 214a and the first plating 214d constituting the second plating row 214b are arranged so as to be shifted in the main scanning direction. 216 is arranged to face the first plating 214c constituting the first plating row 214a in the sub-scanning direction.

  Therefore, even when the second solder 224 is crushed, since the first plating 214 is not disposed near the second plating 214c, the possibility that the second solder 224 and the first solder 222 come into contact with each other is reduced. be able to. Therefore, the possibility that the thermal head X3 is short-circuited can be reduced.

  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 heads X2 to X3 may be used for the thermal printer Z1. Moreover, you may combine the thermal heads X1-X3 which are some embodiment.

  For example, the thermal head X1 and the thermal head X2 may be combined. In other words, the thermal head X1 has the second plating 16 disposed on the signal electrode 6 side of the second connection terminal 20 in a plan view, and the planar view area of the second plating 16 is equal to that of the first plating 14. It is good also as a structure larger than a planar view area. Even in this case, the possibility that the crushed second solder 24 contacts the signal electrode 6 or the ground electrode 4 can be reduced.

  Further, 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.

  Moreover, although the example which connected the connector 31 directly to the head base | substrate 3 was shown, it is not limited to this. A voltage may be supplied to the head base 3 by electrically connecting a wiring board to the head base 3.

In addition, the planar head in which the heat generating portion 9 is formed on the first main surface 7f of the substrate 7 has been described as an example, but the present invention may be applied to the end face head in which the heat generating portion 9 is provided on the end surface of the substrate 7. Good.

  Further, the heat storage layer 13 may form the base portion 13 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.

  The sealing member 12 may be formed of the same material as the hard coat 29 that covers the driving IC 11. In that case, when the hard coat 29 is printed, the hard coat 29 and the sealing member 12 may be formed at the same time by printing also in the region where the sealing member 12 is formed.

X1 to X3 Thermal head Z1 Thermal printer 1 Heat sink 3 Head base 4 Ground electrode (second electrode)
6 Signal electrode 7 Substrate 9 Heating part 11 Drive IC
11a One long side 11b The other long side 13 Heat storage layer 14 First plating 14a First plating row 14b Second plating row 15 Electrical resistance layer 16 Second plating 17 Common electrode 18 First connection terminal 19 Individual electrode (first electrode) )
20 Second Connection Terminal 21 IC-Connector Connection Electrode 22 First Solder 24 Second Solder 25 Protective Layer 27 Covering Layer 31 Connector

Claims (9)

A substrate,
A plurality of heat generating portions provided on the substrate;
A plurality of driving ICs for controlling the driving of the heat generating portion and having a first connection terminal and a second connection terminal;
A plurality of first electrodes that electrically connect the plurality of heat generating units and the plurality of drive ICs, respectively;
A plurality of first platings provided on the plurality of first electrodes;
A plurality of first solders for electrically connecting the first plating and the first connection terminals;
A second electrode electrically connected in common with the plurality of drive ICs;
A plurality of second plating provided on the second electrode;
A plurality of second solders that electrically connect the second plating and the second connection terminals,
A thermal head, wherein the area of the second plating is larger than the area of the first plating in plan view.   2. The thermal head according to claim 1, wherein the second plating is disposed on a side farther than the second connection terminal with respect to the first electrode in a plan view. A substrate,
A plurality of heat generating portions provided on the substrate;
A plurality of driving ICs for controlling the driving of the heat generating portion and having a first connection terminal and a second connection terminal;
A plurality of first electrodes that electrically connect the plurality of heat generating units and the plurality of drive ICs, respectively;
A plurality of first platings provided on the plurality of first electrodes;
A plurality of first solders for electrically connecting the first plating and the first connection terminals;
A second electrode electrically connected in common with the plurality of drive ICs;
A plurality of second plating provided on the second electrode;
A plurality of second solders that electrically connect the second plating and the second connection terminals,
The thermal head, wherein the second plating is disposed on a side farther than the second connection terminal with respect to the first electrode in plan view.   4. The thermal head according to claim 3, wherein an area of the second plating is smaller than an area of the first plating in a plan view.   The thermal head according to any one of claims 1 to 4, wherein the second plating is formed long in the main scanning direction.   The thermal head according to any one of claims 1 to 5, wherein the first plating is formed long in the sub-scanning direction. A first plating row in which the first plating is arranged in the main scanning direction;
A second plating row disposed between the first plating row and the second electrode and having the first plating arranged in a main scanning direction;
The thermal according to claim 6, wherein a length in the sub-scanning direction of the first plating constituting the second plating row is shorter than a length in the sub-scanning direction of the first plating constituting the first plating row. head. The first plating that constitutes the first plating row and the first plating that constitutes the second plating row are arranged shifted in the main scanning direction,
The thermal head according to claim 7, wherein the second plating is opposed to the first plating constituting the first plating row in the sub-scanning direction. The thermal head according to any one of claims 1 to 8,
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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