JP5952176B2 - Thermal head and thermal printer equipped with the same - Google Patents

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, a substrate, a plurality of heat generating portions provided on the substrate, a plurality of electrodes provided on the substrate and electrically connected to the plurality of heat generating portions, and first ends where the ends of the plurality of electrodes are exposed. A device is known that includes a connecting member that is disposed in the exposed portion and electrically connects a plurality of electrodes and the outside, and a protective member that is provided on the substrate and protects at least a part of the connecting member. (For example, refer to Patent Document 1).

Japanese Utility Model Publication No. 02-095642

  However, in the above-described thermal head, the bonding strength of the protective member that protects the connecting member to the substrate is weak, and the protective member may peel off from the substrate. That is, there is a problem that the connection member cannot be firmly bonded to the substrate.

  A thermal head according to an embodiment of the present invention includes a substrate, a plurality of heat generating portions provided on the substrate, and a plurality of electrodes provided on the substrate and electrically connected to the plurality of heat generating portions. A covering member that is provided on the substrate and has a first exposed portion that exposes end portions of the plurality of electrodes, and covers at least a part of the plurality of electrodes other than the end portions; A connecting member that is disposed in the exposed portion and electrically connects the plurality of electrodes and the outside; and a protective member that is provided on the substrate and protects at least a part of the connecting member. . Further, the covering member has a second exposed portion provided to be separated from the first exposed portion. Moreover, the said protection member is arrange | positioned at the said 2nd exposed part.

A thermal head according to an embodiment of the present invention includes a substrate, a plurality of heat generating portions provided on the substrate, and a plurality of electrodes provided on the substrate and electrically connected to the plurality of heat generating portions. A covering member that is provided on the substrate and has a first exposed portion that exposes end portions of the plurality of electrodes, and covers at least a part of the plurality of electrodes other than the end portions; A connecting member that is disposed in the exposed portion and electrically connects the plurality of electrodes and the outside; and a protective member that is provided on the substrate and protects at least a part of the connecting member. . Moreover, the said covering member is spaced apart and provided from the said 1st exposed part, and has the 2nd exposed part which the said board | substrate exposed . Moreover, the said protection member is arrange | positioned at the said 2nd exposed part, and the said protection member and the said board | substrate are joined .

  According to the present invention, the bonding strength between the substrate and the protection member can be improved.

It is a top view which shows one Embodiment of the thermal head of this invention. It is the II sectional view taken on the line shown in FIG. (A) is an enlarged plan view of the vicinity of the connector of the thermal head shown in FIG. 1, and (b) is a cross-sectional perspective view taken along line II-II shown in FIG. 3 (a). (A) is an enlarged plan view of the vicinity of the connector of the thermal head shown in FIG. 1, and (b) is a sectional view taken along line III-III shown in FIG. 4 (a). It is the IV-IV sectional view taken on the line shown to Fig.4 (a). It is a figure which shows schematic structure of one Embodiment of the thermal printer of this invention. FIG. 8 shows a thermal head according to another embodiment of the present invention, in which (a) is an enlarged plan view near the connector corresponding to FIG. 1, and (b) is an enlarged plan view showing a modification of FIG. 7 (a). The thermal head which concerns on other embodiment is shown, (a) is an enlarged plan view of the connector vicinity, (b) is the VV sectional view taken on the line shown to Fig.8 (a). 9 shows a thermal head according to still another embodiment, wherein (a) is an enlarged plan view near the connector, and (b) is a sectional view taken along line VI-VI shown in FIG. 9 (a). The thermal head which concerns on other embodiment of this invention is shown, (a) is an enlarged plan view of a connector vicinity, (b) is an enlarged plan view which shows the modification of Fig.10 (a).

<First Embodiment>
Hereinafter, the thermal head X1 will be described with reference to FIGS. The thermal head X <b> 1 includes a heat radiator 1, a head base 3 disposed on the heat sink 1, and a connector 31 connected to the head base 3. In FIG. 1, the illustration of the connector 31 is omitted, and a region where the connector 31 is arranged is indicated by a one-dot chain line.

  Hereinafter, the connector 31 will be described as a connection member for electrical connection with the outside, but other members such as a flexible printed wiring board, a glass epoxy substrate, or a polyimide substrate are used. May be. When the flexible printed wiring board is electrically connected to the outside, a reinforcing plate (not shown) made of a resin such as phenol resin, polyimide resin, or glass epoxy resin is provided between the flexible printed wiring board and the radiator 1. It may be provided.

  The radiator 1 is formed in a plate shape and has a rectangular shape in plan view. The radiator 1 is formed of a metal material such as copper, iron, or aluminum, for example, 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 bonded to the upper surface of the radiator 1 by a double-sided tape or an adhesive (not shown).

  The head base 3 is formed in a plate 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.

  As illustrated in FIG. 2, the connector 31 includes a plurality of connector pins 8 and a housing 10 that houses the plurality of connector pins 8. One of the plurality of connector pins 8 is exposed to the outside of the housing 10, and the other is accommodated inside the housing 10. The plurality of connector pins 8 have a function of electrically connecting various electrodes of the head base 3 and, for example, a power source provided outside, and each is electrically independent. Since the housing 10 has a function of housing each connector pin 10 in an electrically independent state, it is made of an insulating member. The housing 10 supplies electricity to the head base 3 by attaching and detaching a connector (not shown) provided outside. Since the connector pin 8 needs to have conductivity, the connector pin 8 is formed of a metal or an alloy, and the housing 10 is formed of, for example, a thermosetting resin or a photocurable resin.

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

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

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 over the left half of the upper surface of the substrate 7, 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. have. The base portion 13a is provided in the vicinity of the heat generating portion 9, and is disposed below a protective layer 25 described later. The raised portion 13b functions to favorably press the recording medium to be printed against the protective layer 25 formed on the heat generating portion 9.

  The heat storage layer 13 is formed of glass having low thermal conductivity, and by temporarily storing a part of the heat generated in the heat generating part 9, the time required to raise the temperature of the heat generating part 9 is shortened. And functions to enhance 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 electrical resistance layer 15 is provided on the upper surface of the heat storage layer 13, and the wiring electrode 4, the common electrode 17, the individual electrode 19, the ground electrode 28, and the IC-connector connection electrode 21 are provided on the electrical resistance layer 15. Yes. The electrical resistance layer 15 is patterned in the same shape as the wiring electrode 4, the common electrode 17, the individual electrode 19, the ground electrode 28, and the IC-connector connection electrode 21, and the electrical resistance is between the common electrode 17 and the individual electrode 19. Layer 15 has an exposed area exposed. As shown in FIG. 1, the exposed regions of the electrical resistance layer 15 are arranged in a row on the raised portions 13 b of the heat storage layer 13, and each exposed region constitutes the heat generating portion 9. 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 600 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 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, a common electrode 17, a plurality of individual electrodes 19, a wiring electrode 4, a ground electrode 28, and a plurality of IC-connector connection electrodes 21 are provided on the upper surface of the electrical resistance layer 15. . These common electrode 17, individual electrode 19, wiring electrode 4, ground electrode 28 and IC-connector connection electrode 21 are formed of a conductive material, for example, any of aluminum, gold, silver and copper Or a kind of metal or an alloy thereof.

  The common electrode 17 includes a main wiring portion 17a extending along one long side of the substrate 7, two sub wiring portions 17b extending along one and the other short sides of the substrate 7, and a main wiring portion 17a. And a plurality of lead portions 17c individually extending toward each heat generating portion 9. The common electrode 17 has one end connected to the plurality of heat generating units 9 and the other end connected to the connector 31 to electrically connect the connector 31 and each heat generating unit 9.

  The plurality of individual electrodes 19 have one end connected to the heat generating unit 9 and the other end connected to the drive IC 11 to electrically connect each heat generating unit 9 and the drive IC 11. The individual electrode 19 divides a plurality of heat generating portions 9 into a plurality of groups, and electrically connects the heat generating portions 9 of each group to a drive IC 11 provided corresponding to each group.

  The wiring electrode 4 leads the terminal electrode 2 provided at the center in the longitudinal direction of the head base 3 to both ends of the head base 3 in the longitudinal direction. The wiring electrode 4 is formed along the edge (not shown) of the substrate 7.

The terminal electrode 2 is provided with a temperature measuring member 6 and measures the temperature of the thermal head X1. As the temperature measuring member 12, a chip-type electronic component can be used, and a chip-type thermistor or the like can be exemplified. The temperature measuring member 6 may not be provided in the thermal head X1. In that case, it is not necessary to provide the terminal electrode 2 and the wiring electrode 4 in the thermal head X1.

  The plurality of IC-connector connection electrodes 21 have one end connected to the drive IC 11 and the other end connected to the connector 31, thereby electrically connecting 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.

  The ground electrode 28 is disposed between the IC-connector connection electrode 21 and the wiring electrode 4 and has a large area. The ground electrode 28 is held by a ground electrode of 0 to 1V.

  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 IC 11.

  As shown in FIG. 1, the driving 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 driving IC, a switching member having a plurality of switching elements inside may be used.

  For example, the electrical resistance layer 15, the wiring electrode 10, the common electrode 17, the individual electrode 19, the ground electrode 28, the IC-connector connection electrode 21, and the IC-IC connection electrode 26 may be formed of a material layer constituting each of the heat storage layers. 13 is formed by sequentially laminating the film 13 by a conventionally well-known thin film forming technique such as a sputtering method, and then processing the laminated body into a predetermined pattern using a conventionally well-known photoetching or the like. The wiring electrode 10, the common electrode 17, the individual electrode 19, the ground electrode 28, the IC-connector connection electrode 21, and the IC-IC connection electrode 26 can be simultaneously formed by the same process.

  As shown in FIGS. 1 and 2, a protective layer 25 is formed on the heat storage layer 13 formed on the upper surface of 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. ing. In FIG. 1, for convenience of explanation, the formation region of the protective layer 25 is indicated by a one-dot chain line, and illustration of these is omitted.

  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, SiON, SiC, diamond-like carbon, or the like. 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. 1 and 2, a covering member 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. In FIG. 1, for convenience of explanation, the formation region of the covering member 27 is indicated by a one-dot chain line. The covering member 27 protects the region covered with the common electrode 17, the individual electrode 19 and the IC-connector connection electrode 21 from oxidation due to contact with the atmosphere or corrosion due to adhesion of moisture contained in the atmosphere. belongs to. The covering member 27 is formed so as to overlap the end portion of the protective layer 25 as shown in FIG. 2 in order to ensure the protection of the common electrode 17 and the individual electrode 19. The covering member 27 can be formed of a resin material such as an epoxy resin or a polyimide resin by using a thick film forming technique such as a screen printing method.

  The covering member 27 is formed with an opening (not shown) for exposing the individual electrode 19 connected to the driving IC 11 and the IC-connector connection electrode 21, and these wirings are connected to the driving IC 11 through the opening. It is connected to the. In addition, the drive IC 11 is connected to the individual electrode 19 and the IC-connector connection electrode 21 to protect the drive IC 11 and to protect the connection portion between the drive IC 11 and these wirings. It is sealed by being covered with a hard coat 29 made of such a resin. The height of the covering member 27 can be appropriately set according to the aspect of the thermal head X1, but is preferably 10 to 30 μm.

  The electrical connection between the connector 31 and the head base 3 will be described with reference to FIGS. In FIG. 3, the protection member 12 that covers the connector 31 and the connector 31 are not shown.

  As shown in FIG. 3A, the covering member 27 is provided with a first exposed portion 14 and a second exposed portion 16 at the end of the head base 3. The IC-connector connection electrode 21 is exposed from the first exposed portion 14 and the second exposed portion 16, and the IC-connector connection electrode 21 is electrically connected to the connector 31 in the first exposed portion 14. Therefore, the first exposed portion 14 becomes a connection region for electrically connecting the head base 3 and the connector 31. In addition, although the edge part of the ground electrode 28 (refer FIG. 1) and the edge part of the wiring electrode 10 (refer FIG. 1) are exposed, the example which the IC-connector connection electrode 21 is exposed for convenience is used. explain.

  The covering member 27 has a plurality of extending portions 18 extending toward the first exposed portion 14, and each extending portion 18 extends between adjacent IC-connector connection electrodes 21. In addition, the covering member 27 is formed between the extending portions 18 positioned at both ends of the arrangement direction of the IC-connector connection electrodes 21 (hereinafter sometimes referred to as arrangement direction) in the first exposed portion 14 in plan view. The interval is wider than the interval between the extending portions 18 located at the center in the arrangement direction. Here, the both end portions in the arrangement direction indicate regions from both ends of the first exposed portion 14 to 20% of the length in the arrangement direction of the first exposed portion 14, respectively, and the central portion in the arrangement direction means both end portions. Indicates an area other than.

  Further, the first exposed portion 14 is partitioned by the extending portion 18 of the covering member 27. That is, the first exposed portion 14 is provided so as to be surrounded by the covering member 27 in plan view. Furthermore, the second exposed portion 16 is provided so as to surround the first exposed portion 14 and the covering member 27 surrounding the first exposed portion 14 in plan view. The second exposed portion 16 is surrounded by the covering member 27 in plan view.

  As shown in FIGS. 4B and 5, the connector 31 is provided on the substrate 7, and the IC-connector connection electrode 21 and the connector pin 8 are electrically connected by the conductive member 20. . The conductive member 20 can be exemplified by, for example, an anisotropic conductive adhesive in which conductive particles are mixed in solder or an electrically insulating resin. In this embodiment, the conductive member 20 will be described using solder. The connector pin 8 is electrically connected by being covered with the conductive member 20. A plating layer (not shown) of Ni, Au, or Pd may be provided between the conductive member 20 and the IC-connector connection electrode 21.

As shown in FIGS. 4 and 5, the thermal head X <b> 1 is provided with a protective member 12 for protecting at least a part of the connector 31. The protection member 12 is provided so as to cover the connector pin 8, a part of the upper surface of the housing 10, and a part of the covering member 27. A part of the covering member 27 covered with the protective member 12 includes the covering member 27 provided on the first exposed portion 14, the second exposed portion 16, and between the first exposed portion 14 and the second exposed portion 16. On the top and the covering member 27 provided around the second exposed portion 16. In other words, the protective member 12 has the second dew point in plan view.
It is provided so as to completely cover the protruding portion 16.

  Therefore, the protection member 12 is provided in the first exposed portion 14 except for the connector pin 8, the conductive member 20, the IC-connector connection electrode 21, and the electrical resistance layer 15. Further, the protection member 12 is disposed in the second exposed portion 16. That is, the protection member 12 is provided so as to enter the first exposed portion 14 and the second exposed portion 16 provided in the covering member 27.

  Thereby, the anchor effect by the protective member 12 entering the first exposed portion 14 and the second exposed portion 16 is generated, and the bonding strength between the substrate 7 and the protective member 27 can be improved. In particular, when the covering member 12 is provided on the second exposed portion 16, a contact surface is formed where the side surface forming the second exposed portion 16 and the protective member 12 come into contact with each other. As a result, the bonding strength can be improved. Further, in the first exposed portion 14, the electrical continuity between the IC-connector connection electrode 21 and the connector pin 8 can be obtained, and the electrical continuity can be protected by the protection member 12.

  Furthermore, the surface of the substrate 7 exposed from the first exposed portion 14 and the second exposed portion 16 is rougher than the surface of the covering member 27, and the resin constituting the protective member 12 on the surface irregularities of the substrate 7. The particles can enter and the bonding strength can be further improved.

  Further, the second exposed portion 16 is provided so as to surround the first exposed portion 14 in plan view. Therefore, the protection member 12 is configured to enter the second exposed portion 16 provided around the first exposed portion 14 that is electrically connected to the connector 31. Accordingly, the periphery of the first exposed portion 14 can be firmly fixed, and an external force is applied to the conductive member 20 connecting the connector pin 8 and the IC-connector electrode 21 provided in the first exposed portion 14. It is possible to reduce the possibility of applying stress generated during the process. As a result, electrical continuity between the head base 3 and the outside can be ensured.

  The protective member 12 can be formed of, for example, a thermosetting resin, a thermosoftening resin, or a photocurable resin. Moreover, when each IC-connector connection electrode 21 needs to be electrically independent, it is preferable that it is insulating.

  Moreover, although the protection member 12 is protecting electrical continuity by covering the connector pin 8 of the connector 31, it is preferable to be provided in a part of upper surface of the housing 10, as shown in FIG. Thereby, the whole area | region of the connector pin 8 can be covered with the protection member 12, and also electrical conduction can be protected.

  Further, as shown in FIG. 5, it is preferably provided between the housing 10 and the end surface 7 a of the substrate 7. Accordingly, the protective member 12 provided on the upper surface of the connector 31 increases the bonding strength in the thickness direction of the substrate 7, and the protective member 12 provided between the housing 10 and the end surface 7 a of the substrate 7 allows the connector pin to be connected. The joint strength in the extending direction of 8 can be increased. Therefore, the bonding strength between the substrate 7 and the connector 31 can be further increased. In particular, by providing the protective member 12 on a part of the upper portion of the housing 10, it is possible to improve the bonding strength of the upper portion of the housing 10 where peeling easily occurs. The end surface 7a of the substrate 7 and the housing 10 may be in contact with each other without providing a gap between the end surface 7a of the substrate 7 and the housing 10.

As shown in FIG. 4A, it is preferable that the protective member 12 is provided in a region 30 sandwiched between the side surface of the housing 10 of the connector 31 and the end surface 7 a of the substrate 7. By providing the protection member 12 in the region 30, the housing 10 can be firmly fixed to the substrate 7. That is, when an external force is applied to the housing 10 in the arrangement direction, the protective member 12 provided in the region 30 can relieve the external force. In addition, as shown in FIG. 4A, the protective member 12 provided in the region 30 preferably has a convex shape with its side surface facing the end surface 7 a of the substrate 7 and the side surface of the housing 10 in plan view. . Thereby, the connector 31 can be firmly fixed to the external force in the arrangement direction.

  The covering member 27 includes a plurality of extending portions 18. Therefore, when the protection member 12 is cured, the extending portion 18 is configured to bite into the protection member 12. Furthermore, the contact area between the protection member 12 and the covering member 27 can be increased, and the bonding strength between the substrate 7 and the protection member 12 can be increased.

  Moreover, since the extending | stretching part 18 partitions off each connector pin 8, when joining the connector 31 to the board | substrate 7, it functions as a marker for arrange | positioning the connector pin 8, and can improve visibility. Moreover, the electrical independence of each connector pin can be maintained.

  Furthermore, in the 1st exposure part 14, the space | interval of the extending | stretching part 18 located in the both ends of an arrangement direction is a structure wider than the space | interval of the extending | stretching part 18 located in the center part of an arrangement direction. Therefore, the amount of the protective member 12 at both ends in the arrangement direction can be made sufficient, and the bonding strength at both ends in the arrangement direction can be improved.

  In addition, although the example which uses a solder as the electrically-conductive member 20 was illustrated, you may use an anisotropic conductive adhesive. In that case, an anisotropic conductive adhesive is provided over the entire area of the first exposed portion 14, and the protective member 12 is provided so as to cover the anisotropic conductive adhesive, the covering member 27, and the second exposed portion 16. While securing the bonding strength between the substrate 7 and the protection member 12, the anisotropic conductive adhesive and the connector pin 8 that require electrical conduction can be protected.

  In addition, although the example in which the protective member 12 is disposed also in the first exposed portion 14 is shown, the protective member 12 may be disposed only in the second exposed portion 16. Even in that case, the bonding strength between the substrate 7 and the protective member 12 can be improved by the protective member 12 entering the second exposed portion 16.

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

  As shown in FIG. 6, 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 that the arrangement direction of the heat generating portions 9 is 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 the figure, and transports the recording medium P onto the protective layer 25 positioned on the plurality of heat generating portions 9 of the thermal head X1. Is to do. 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. 6, 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 the thermal head X2, the coating layer 27 has two second exposed portions 16 and 16 ′. That is, the second exposed portion 16 ′ is further provided outside the second exposed portion 16 of the thermal head X1. In plan view, the shapes of the second exposed portions 16, 16 'are similar to each other. Here, the mutually similar shapes mean that regions of 85% or more overlap when they have the same size, and are a concept including a manufacturing error plus or minus 15%.

  As described above, since the thermal head X2 includes the plurality of second exposed portions 16 and 16 ′, more protective members 12 enter the coating layer 27, and the substrate 7 and the protective members 12 The bonding strength can be further improved. In addition, since the second exposed portions 16 and 16 ′ are similar to each other, the distribution of stress applied to the first exposed portion 14 surrounded by the second exposed portions 16 and 16 ′ can be made uniform. Therefore, the stress generated in each connector pin 8 can be made to be uniform, and electrical continuity can be ensured.

  In addition, although the shape of the second exposed portions 16 and 16 ′ is a rectangular shape in plan view, the shape is not limited thereto. For example, in plan view, the shape of the second exposed portions 16, 16 ′ may be circular, elliptical, or wave shape.

  In the thermal head X2, an example in which two second projecting portions 16 having a similar shape to each other in plan view are illustrated, but the present invention is not limited to this. Three or more second protrusions 16 may be provided, and the plurality of second protrusions 16 may not be similar to each other.

  A thermal head X2 ′, which is a modification of the thermal head X2, will be described with reference to FIG. In the thermal head X2 ′, the second exposed portions 16 ′ are separately provided. That is, the second exposed portion 16 ′ is provided outside both ends of the first exposed portion 14 in the arrangement direction, and the two second exposed portions are arranged outside in the direction orthogonal to the arranged direction of the first exposed portion 14. A portion 16 'is provided.

  Thus, even when the second exposed portions 16 ′ are provided separately, the protective member 12 is configured to enter the second exposed portions 16 ′, and the bonding strength between the substrate 7 and the protective member 12 is improved. be able to.

<Third Embodiment>
The thermal head X3 will be described with reference to FIG. In the thermal head X <b> 3, the covering member 27 has a plurality of extending portions 18 and a wide portion 22 along the edge 7 b of the substrate 7. Further, the IC-connector connection electrode 21 is provided apart from the edge 7 b of the substrate 7.

  As shown in FIG. 8B, one end of the connector pin 8 is supported by the covering member 27, and the other end is supported by the wide portion 22 of the covering member 27. Therefore, the connector pin 8 is configured to be supported at two points of the covering member 27 and the wide portion 22.

  Here, when the connector pin 8 is pressed against the substrate 7, the conductive member 20 is crushed, and there is a possibility that the electrical continuity between the connector pin 8 and the IC-connector connection electrode 21 is interrupted. In the head X3, electrical continuity can be ensured by supporting the connector pins 8 at two points. In addition, a space can be secured between the connector pin 8 and the IC-connector electrode 21, a sufficient amount of solder can be secured, and electrical continuity can be secured.

  Further, since the connector pin 8 is supported by the wide portion 22, the possibility that the other end portion of the connector pin 8 is pushed toward the substrate 7 can be reduced. Therefore, the possibility of peeling from one end of the connector pin 8 can be reduced.

  In the thermal head X3, the example in which the wide portion 22 is continuously provided from one end to the other end of the covering member 27 that forms the first exposed portion 14 and the second exposed portion 16 is shown, but is not limited thereto. It is not something. The wide portion 22 only needs to be between the edge 7b of the substrate 7 and the IC-connector connection electrode 21. For example, the wide portion 22 is provided only between the edge 7b of the substrate 7 and the IC-connector connection electrode 21, The wide portion 22 may be intermittent in the arrangement direction.

  Further, in the thermal head X3, the connector pin 8 is supported by the covering member 27 and the wide portion 22 and is connected to the substrate 7 in a state parallel to the surface of the substrate 7. It is not limited to.

  For example, the connector 31 may be disposed so that the tip of the connector pin 8 abuts against the covering member 27, and the connector pin 8 may be supported only by the wide portion 22. In this case, the connector pin 8 is configured to incline downward with respect to the main surface of the substrate 7 as the connector pin 8 extends. However, since the connector pin 8 is supported by the wide portion 22, the amount of solder is ensured. can do. Further, by positioning the tip of the connector pin 8 against the covering member 27, the positioning of the connector 31 can be facilitated.

<Fourth Embodiment>
The thermal head X4 will be described with reference to FIG. In the thermal head X 4, the IC-connector connection electrode 21 is provided away from the edge 7 b of the substrate 7. The protective member 12 is provided in a region 24 between the IC-connector connection electrode 21 and the edge 7 b of the substrate 7. Further, as shown in FIG. 9B, the end surface 7a of the substrate 7 is chamfered to form a chamfer 28.

Thus, the protective member 12 is disposed in the region 24, and in the vicinity of the region 24,
The connector pin 8 is sealed by the protection member 12. Further, the protective member 12 is also disposed on the chamfer 28 of the substrate 7. Therefore, the protection member 12 is disposed in the first exposed portion 14, the second exposed portion 16, the covering member 27, a part of the housing 10, between the housing 10 and the end face of the substrate 7, and in the region 24. . Therefore, the bonding strength between the substrate 7 and the protection member 12 can be improved.

  In particular, all the portions of the connector pin 8 protruding from the housing 10 can be sealed with the protective member 12, and the possibility that the connector pin 8 is corroded can be reduced.

  Further, since the protective member 12 is disposed on the chamfer 28 of the substrate 7, the protective member 12 is bitten by the chamfer 28 of the substrate 7 even when the substrate 7 is deformed in the thickness direction of the substrate 7. Therefore, the connector 31 can also follow the deformation of the substrate 7, and the possibility that the connector 31 peels from the substrate 7 can be reduced.

<Fifth Embodiment>
The thermal head X5 will be described with reference to FIG. In the thermal head X5, the covering member 27 has a plurality of extending portions 18, and the length of the extending portions 18 located at both ends in the arrangement direction is the length of the extending portion 18 located in the center portion in the arrangement direction. This is a shorter configuration.

  Thereby, a sufficient amount of the protective member 12 can be supplied to both ends in the arrangement direction, and the bonding strength between the substrate 7 and the protective member 12 can be improved. That is, the possibility that the connector 31 is peeled from the substrate 7 can be reduced by improving the bonding strength between the connector 31 and the substrate 7 at both ends in the arrangement direction where peeling is likely to occur.

  Further, as shown in FIG. 10B, the extending portions 18 positioned at both end portions in the arrangement direction may extend from the edge of the substrate 7. Even in this case, an equivalent effect can be obtained.

  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 X5 may be used for the thermal printer Z1. Moreover, you may combine the thermal heads X1-X5 which are some embodiment.

  For example, by combining the thermal heads X1 and X5, the length of the extending portion 18 located at both ends in the arrangement direction is made shorter than the length of the extending portion 18 located in the center portion in the arrangement direction, and both end portions in the arrangement direction The interval between the extending portions 18 positioned at the center may be longer than the interval between the extending portions 18 positioned at the center portion in the arrangement direction. Even in such a case, a sufficient amount of the protective member 12 can be supplied to both ends in the arrangement direction, which is a connection region with the connector 31, and the bonding strength can be improved.

  In the thermal head X1, the raised portion 13b is formed on the heat storage layer 13 and the electric resistance layer 15 is formed on the raised portion 13b. However, the present invention is not limited to this. For example, the heat generating portion 9 of the electric resistance layer 15 may be disposed on the base portion 13 a of the heat storage layer 13 without forming the raised portion 13 b in the heat storage layer 13. Alternatively, the heat storage layer 13 may be provided over the entire upper surface of the substrate 7. Even in that case, the protective member 12 can be caused to enter the surface of the heat storage layer 13 by the second exposed portion 16, and the bonding strength between the substrate 7 and the protective member 12 can be improved.

In the thermal head X 1, the common electrode 17 and the individual electrode 19 are provided on the electric resistance layer 15.
However, the present invention is not limited to this as long as both the common electrode 17 and the individual electrode 19 are connected to the heat generating portion 9 (electric resistor). For example, even if the heat generating portion 9 is configured 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.

  Furthermore, 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. For example, 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.

  The protective member 12 and the hard coat 29 that covers the drive IC 11 may be formed of the same material. In this case, when the hard coat 20 is printed, the hard coat 29 and the protective member 12 can be simultaneously formed by printing also in the region where the protective member 12 is formed.

  In the thermal heads X1 to X5, the connector 31 is connected at both ends in the arrangement direction of the substrates 7, and the head base 3 and the power source provided outside are connected. However, the present invention is not limited to this. It is not something. For example, the method of drawing various electrodes may be changed to connect to the connector 31 only at the central portion in the arrangement direction of the substrates 7. Even in this case, an equivalent effect can be obtained.

X1 to X5 Thermal head Z1 Thermal printer 1 Radiator 3 Head base 7 Substrate 8 Connector pin 9 Heating part (electric resistor)
10 Housing 11 Drive IC
DESCRIPTION OF SYMBOLS 12 Protective member 13 Thermal storage layer 14 1st exposed part 15 Electrical resistance layer 16 2nd exposed part 17 Common electrode 18 Extending part 19 Individual electrode 20 Conductive member 21 IC-connector connection electrode 22 Wide part 23 Joining material 24 Bonding of electrode and edge Area 25 Protective layer 26 IC-IC connection electrode 27 Cover member 28 Chamfer 29 Hard coat

Claims (10)

A substrate,
A plurality of heat generating portions provided on the substrate;
A plurality of electrodes provided on the substrate and electrically connected to the plurality of heat generating units;
A covering member that is provided on the substrate, has a first exposed portion where the ends of the plurality of electrodes are exposed, and covers at least a portion other than the ends of the plurality of electrodes;
A connecting member disposed in the first exposed portion and electrically connecting the plurality of electrodes and the outside;
A protective member provided on the substrate and protecting at least a part of the connection member,
The covering member is provided apart from the first exposed portion, and has a second exposed portion where the substrate is exposed ,
The protective member is disposed in the second exposed portion, and the protective member and the substrate are bonded to each other.   The thermal head according to claim 1, wherein the second exposed portion is provided so as to surround the first exposed portion in a plan view. A plurality of the second exposed portions are provided,
The thermal head according to claim 2, wherein the plurality of second exposed portions are similar to each other in a plan view. The electrode is spaced from the edge of the substrate;
The thermal head according to claim 1, wherein the covering member is provided between the electrode and the edge. The electrode is spaced from the edge of the substrate;
The thermal head according to claim 1, wherein the protection member is disposed between the electrode and the edge. The connection member is connected to the end portions of the plurality of electrodes through a conductive member in the first exposed portion,
The thermal head according to claim 1, wherein the protection member is also disposed in the first exposed portion. The connection member is connected to the end portions of the plurality of electrodes through a conductive member in the first exposed portion,
7. The thermal head according to claim 1, wherein the covering member has at least one extending portion extending between the adjacent electrodes in the first exposed portion in plan view. The covering member has a plurality of the extending portions,
In plan view, in the first exposed portion, the length of the extending portion located at both ends in the arrangement direction of the electrodes is shorter than the length of the extending portion located in the center portion in the arrangement direction of the electrodes. The thermal head according to claim 7. The covering member has a plurality of the extending portions,
In plan view, in the first exposed portion, an interval between the extending portions at both ends in the arrangement direction of the electrodes is larger than an interval between the extending portions in a central portion in the arrangement direction of the electrodes. The thermal head according to 7 or 8.   A thermal head according to any one of claims 1 to 9, a transport mechanism for transporting a recording medium onto the heat generating portion, and a platen roller for pressing the recording medium onto the heat generating portion. Features a thermal printer.

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