JP2007216403A - Thermal head and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the size of a support substrate having a heating element formed thereon, to form a circuit pattern applicable to a large current on a thermal head, and to provide the thermal head wherein the top of the heating element can be readily abutted on an ink ribbon, and a method for manufacturing the thermal head. <P>SOLUTION: In this thermal head, the support substrate 21 is housed in a first housing space 12 formed on a circuit board 2 and electrodes 23, 24 and connection electrodes 25, 26 are formed on the support substrate 21. Conductive material layers 18, 28 formed on one surface 2a of the circuit board 2 are projected in the housing space 12 to be connected to the connection electrodes 25, 26. An IC 31 is housed in a second housing space 13 and the conductive material layers 28, 38 formed on the one surface 2a of the circuit board 2 are projected in an opening of the housing space 13 connected to connection electrodes 32, 33 formed on the IC 31. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermal head used for a video printer, other thermal transfer printers, and the like, and a manufacturing method thereof.

  In a thermal head used for a thermal transfer printer or the like, a heating element made of an electric resistor is formed on a surface of a support substrate made of ceramic, glass or metal by a firing process or the like. Further, an IC for driving and controlling the heating element is mounted on the thermal head.

  In the thermal head described in Patent Document 1 below, a heating element is provided on the surface of a support substrate, and an IC is provided so as to protrude on the same side as the heating element. For this reason, if an ink ribbon or printing paper provided in the printer is made to face the heating element in parallel with the surface of the support substrate, the ink ribbon or the like may hit the IC. Therefore, when using the thermal head described in Patent Document 1, it is necessary to dispose the support substrate obliquely with respect to the surface of the ink ribbon or the like and to retract the IC to a position away from the ink ribbon.

  The top of the heating element has the highest heat generation temperature. However, if the support substrate is disposed obliquely with respect to the ink ribbon as described above, the portion other than the top of the heating element hits the ink ribbon, etc. The body's heat utilization efficiency becomes worse. Furthermore, since the support substrate is attached obliquely to the print head, the positioning and fixing structure of the heating element becomes complicated.

  In the thermal head described in Patent Document 2 below, a support member is attached at an oblique angle to a support substrate having a heating element, and an IC is provided on the surface of the oblique support member. In this thermal head, the top of the heating element can be brought into contact with the ink ribbon or the like with the support substrate facing the surface of the ink ribbon or the like in parallel. However, since the structure of the thermal head is a complicated structure in which a support member having an IC is attached obliquely to a support substrate having a heating element, the manufacturing process becomes complicated. In addition, the structure of the print head on which the thermal head is mounted is complicated.

  In the thermal head described in Patent Document 3 below, a heating element is provided on the surface of a support substrate made of ceramic or glass material, and a hole is formed in the support substrate. It has been. And the wiring pattern which connects a heat generating body and IC is formed in the surface of a support substrate. In this thermal head, since the IC is retracted from the surface of the support substrate where the heating element is provided, the top of the heating element abuts against an ink ribbon or the like arranged in parallel with the surface of the support substrate. It is easy to let them.

However, since the power supplied to the heating element is a large current, it is necessary to form a wiring pattern formed on the surface of the support substrate in a wide area. Therefore, it is necessary to form the support substrate in a large area. In this case, if a support substrate formed of a ceramic or glass material, which is an expensive material, is used in a large area, the number of support substrates that can be manufactured at one time from a single substrate material is limited, and the cost of the entire thermal head Becomes higher.
JP 2002-264377 A Japanese Patent Laid-Open No. 5-116361 Japanese Patent Laid-Open No. 10-100457

  The present invention solves the above-described conventional problems, has a structure in which the top of the heating element is easily brought into contact with an ink ribbon, and the like, and the support substrate formed of ceramic or the like can be made small, and the heating element and the electronic element It is an object to provide a thermal head capable of forming a wiring pattern between and a wide area.

  Another object of the present invention is to provide a method for manufacturing a thermal head that can efficiently manufacture the thermal head.

The present invention relates to a thermal head including a support substrate, a heating element provided on the surface of the support substrate, an electronic element that drives and controls the heating element, and a wiring board on which the support substrate and the electronic element are mounted. ,
A plurality of through holes or concave storage spaces are formed on one surface side of the wiring substrate, the support substrate is stored in any of the storage spaces, and the heating element protrudes from one surface of the wiring substrate. The electronic device is housed in another housing space.

  In the thermal head, a support substrate having a heating element is configured as a member different from the wiring board, and the support substrate is housed in the storage space of the wiring board. The formed support substrate can be made small. In addition, since the wiring pattern for connecting the heating element and the electronic element can be formed on the wiring board, the wiring pattern can be freely designed and a wiring pattern having a wide area capable of handling a large current can be formed. Furthermore, since the wiring board can draw wiring patterns on its two surfaces, or the wiring board can have a multilayer wiring structure, the wiring board can be made thin and small. As a result, this wiring The entire thermal head including the substrate can be easily downsized.

  In the present invention, it is preferable that the electronic element does not protrude from one surface of the wiring board, or even if the electronic element protrudes from the one surface, the top of the heating element is It is in the position away from one surface of the said wiring board rather than the protrusion side edge part.

  If the top of the heating element is located farther from one surface of the wiring board than the electronic element, the electronic element will not interfere with the ink ribbon or the like when the wiring board is opposed to the ink ribbon or the like in parallel. . Therefore, the fixing structure for mounting the thermal head can be simplified, and the heating element can be easily positioned. Furthermore, since the top of the heating element can be brought into contact with an ink ribbon or the like, the utilization efficiency of heat generated from the heating element is improved. Furthermore, the above-described effect can be further improved by providing a structure in which the electronic element does not protrude from one surface of the wiring board.

  In the present invention, a surface of the support substrate having a heating element is provided with a plurality of electrodes connected to the heating element, and a conductor layer provided on one surface of the wiring board is provided on the support substrate. It extends to the position which overlaps with the surface, It can comprise as the said electrode and the said conductor layer being connected.

  Since the conductor layer, which is a wiring pattern formed on the wiring board, is formed at a position overlapping the support board, even if the support board having a heating element is small, the conductor layer and the support board The provided electrode can be reliably conducted. Even if the area of the support substrate is small, a conductor layer having a large area can be formed on the surface of the wiring substrate, so that a large current can be applied to the heating element.

  Further, according to the present invention, the conductor layer provided on one surface of the wiring board extends to a position facing the electrode of the electronic element, and the electrode of the electronic element and the conductor layer are connected. Can be configured.

  In the above configuration, an electronic element such as an IC housed in the storage space of the wiring board does not protrude from the surface of the wiring board, and the electronic element and the conductor layer on the surface of the wiring board are reliably conducted. be able to. As a result, it is possible to sufficiently widen the distance between the electronic element and the ink ribbon while the top of the heating element is in contact with the ink ribbon or printing paper.

For example, according to the present invention, a plurality of first electrodes connected to one side of the heating element and a plurality of second electrodes connected to the other side of the heating element are provided on the surface of the support substrate. And the heating element located between the first electrode and the second electrode can be partially heated,
The wiring board is provided with a plurality of first conductor layers individually connected to the plurality of first electrodes and a common conductor layer electrically connected to the plurality of second electrodes. The first electrode, the second electrode, and the electronic element are connected via the first conductor layer and the common electrode layer.

  In this case, the present invention can be configured such that both the first conductor layer and the common conductor layer are formed on one surface of the wiring board. Alternatively, at least one of the first conductor layer and the common conductor layer may be configured to pass through the other surface of the wiring board or the inside of the wiring board. Moreover, it is preferable that one of the first conductor layer and the common conductor layer passes through the other surface of the wiring board or the inside of the wiring board and a region overlapping with the supporting board.

  In the above configuration, when the common conductor layer is formed on the surface of the wiring board, the area of the common conductor layer can be sufficiently widened to supply a large current to the heating element. In addition, by forming a common conductor layer or the like on the other surface of the wiring board or inside the wiring board having a multilayer structure, the wiring board can be made to have a small area, and a large current is applied to the common conductor layer. Can be supplied.

  In the present invention, an insulating layer that covers the conductor layer is preferably provided on one surface of the wiring board.

  In the above configuration, since the conductor layer is not exposed from one surface of the wiring board, the conductor layer can be made less susceptible to the influence of foreign matters in the use environment, the humidity, and the like.

  Further, the support substrate is formed of any one of a ceramic material, a glass material, and a metal material. With this configuration, a thermal head having sufficient heat resistance can be configured.

Next, the manufacturing method of the thermal head of the present invention is as follows.
(A) forming a conductor layer on the surface of a dummy substrate having holes or recesses;
(B) A support substrate provided with a heating element on the surface and an electrode connected to the heating element is opposed to the surface of the dummy substrate, and the heating element is inserted into the hole or recess, Connecting the conductor layer to face each other;
(C) simultaneously or before and after the step (b), connecting an electronic element for driving and controlling the heating element to the conductor layer;
(D) A wiring board on which through holes or a plurality of concave storage spaces are formed is installed on the surface of the dummy substrate, the support substrate is stored in one of the storage spaces, and the electronic element is stored in another storage space. And fixing the conductor layer to the surface of the wiring board;
(E) peeling the dummy substrate from the conductor layer fixed to the wiring substrate;
It is characterized by having.

  In the manufacturing method of the thermal head, a supporting substrate having a heating element and an electronic element such as an IC can be accommodated in a storage space formed on the wiring substrate, respectively. A conductor layer connected to the electronic element can be formed.

In addition, the manufacturing method of the thermal head of the present invention,
After the step (d),
(F) It is preferable to have a step of covering the conductor layer provided on the surface of the wiring board with an insulating layer.

  For example, in the thermal head manufacturing method of the present invention, the wiring board is a prepreg material, and the wiring board is thermocompression bonded to the dummy board in the step (d).

  When the wiring member is formed of a prepreg material and is crimped to the dummy substrate by thermocompression bonding, the conductor layer formed on the surface of the dummy substrate can be fixed to the surface of the wiring substrate, and the dummy substrate is attached to the surface of the wiring substrate. It becomes easy to peel from.

  In the thermal head of the present invention, the support substrate having the heating element can be made small, and the conductor layer for supplying a current to the heating element can be freely routed and a conductor layer capable of handling a large current can be formed. It is also possible to bring the top of the heating element into contact with an ink ribbon or printing paper.

  In the thermal head manufacturing method of the present invention, the thermal head having the above-described configuration can be easily manufactured.

  FIG. 1 is a partial plan view showing a thermal head according to a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the thermal head according to the first embodiment.

  As shown in FIGS. 1 and 2, the thermal head 1 has a wiring board 2. The wiring board 2 is a multilayer board formed of an electrically insulating material. The wiring substrate 2 includes a core material substrate 3, a pressure-bonding substrate 4 superimposed on one surface of the core material substrate 3, and a pressure-bonded substrate 5 stacked on the other surface of the core material substrate 3. . The core material substrate 3 is a hard substrate formed of glass epoxy or the like. The pressure-bonding substrate 4 and the pressure-bonding substrate 5 are formed of a prepreg material such as glass epoxy. The prepreg material is formed of a glass epoxy material that is not completely cured, and is cured by applying pressure under heating.

  Wiring patterns 6 and 7 are formed on both surfaces of the core substrate 3. The surface of one pressure-bonding substrate 4 is a facing surface (one surface) 2a of the wiring substrate 2, and a conductor layer 8 serving as a wiring pattern is formed on the facing surface 2a. Further, the surface of the other pressure-bonding substrate 5 is the other surface of the wiring substrate 2, and the wiring pattern 9 is also formed on this surface. Each of the wiring patterns 6, 7, 9 and the conductor layer 8 is formed of at least one conductive material layer such as silver, gold, copper, nickel, or carbon. A plurality of holes penetrating the wiring board 2 in the thickness direction are filled with conductors 11, and the wiring patterns 6, 7 and the wiring patterns 9 provided on the respective layers of the wiring board 2 by the conductors 11. The conductor layer 8 is electrically connected to each other. The conductor 11 is composed of a thermosetting resin binder and a conductive filler such as silver, gold, or carbon, and is cured by heat treatment in the manufacturing process.

  The wiring substrate 2 is formed with a first storage region 12 and a second storage region 13 formed by through holes penetrating in the thickness direction. The first storage area 12 and the second storage area 13 are not limited to through holes, and may be bottomed recesses that open to the opposite surface 2a. As shown in FIG. 1, the first storage space 12 has a rectangular shape when viewed in a plane, and the second storage space 13 has a rectangular shape.

  A support substrate 21 is stored in the first storage space 12. The support substrate 21 is a ceramic substrate such as alumina, or a metal substrate such as glass or aluminum alloy. A heating element 22 is provided on the surface 21 a of the support substrate 21. The heating element 22 is an electric resistance material, is formed of tantalum nitride (TaN) or the like, and is formed by sintering the surface 21 a of the support substrate 21. As shown in FIG. 1, the heating element 22 has a long shape continuously extending in the long side direction of the rectangular shape of the first storage space 12. Further, as shown in FIG. 2, the heating element 22 has an edge shape in a cross-sectional shape having a convex curve shape, and its top portion 22 a is on the opposite side of the wiring board 2 as compared with the other surface of the heating element 22. It protrudes to a position farthest from the surface (one surface) 2a.

  A plurality of first electrodes 23 each connected to one long side of the heating element 22 and a plurality of second electrodes respectively connected to the other long side of the heating element 22 are formed on the surface 21 a of the support substrate 21. The electrode 23 is formed. Each of the electrodes 23 and 24 is patterned with a low resistance material such as silver, gold, copper, or nickel. When a current is applied to the first electrode 23, the second electrode 24, and the heating element 22, the heating element 22 partially generates heat at a location where the first electrode 23 and the second electrode 24 face each other. To do. Therefore, the heating element 22 has heating points corresponding to the number of first electrodes 23 and the number of second electrodes 24. At the heat generation point, the heat generation temperature is highest at the top 22a of the heat generating element 22. Further, when the heating element 22 comes into contact with an ink ribbon or printing paper, the contact area between the top 22a and the ink ribbon is reduced, and the top 22a is brought into contact with the ink ribbon, so that the thermal efficiency used for printing is increased. Will be better.

  As shown in FIG. 2, each first electrode 23 formed on the surface 21 a of the support substrate 21 has a connection electrode 25 formed of a gold bump or the like protruding so as to be formed on the second electrode 24. Similarly, a connection electrode 26 formed of a gold bump or the like is protruded.

  The first storage space 12 of the wiring board 2 is filled with a thermosetting sealing material 27 such as an epoxy resin, and the support substrate 21 stored in the storage space 12 is sealed. The material 27 is fixed to the wiring board 2.

  In the second storage space 13 of the wiring board 2, an IC 31 that is an electronic element is stored. The IC 31 is a bare chip or an IC package in which the bare chip is housed in a package. Connection electrodes 32 and 33 formed of gold bumps or gold balls are formed on the surface of the IC 31. Further, the second storage space 13 is filled with a thermosetting sealing material 34 such as an epoxy resin, and the IC 31 is fixed to the wiring board 2 by the sealing material 34. The material of the connection electrodes 32 and 33 is not limited to gold, and solder or other materials can be used.

  In FIG. 1, the conductor layer 8 formed on the opposite surface 2 a of the insulating substrate 2 is hatched so as to be easily distinguished from other portions. A first conductor layer 18 is constituted by a part of the conductor layer 8 formed on the opposite surface 2a. A plurality of first conductor layers 18 are formed with a predetermined width, and each is independent. One end 18 a of each first conductor layer 18 protrudes into the opening of the first storage space 12 and faces the surface 21 a of the support substrate 21 located in the storage space 12. The end portions 18a of the individual first conductor layers 18 are individually connected to the connection electrodes 25 provided on the surface 21a of the support substrate 21 in a one-to-one relationship. When the surface of the first conductor layer 18 is made of gold, an ultrasonic wave is applied to the joint between the first conductor layer 18 and the connection electrode 25, and a so-called flip chip bonding process is performed. The first conductor layer 18 and the connection electrode 25 are joined. Furthermore, the edge 18 a of the first conductor layer 18 and the surface 21 of the support substrate 21 are fixed with an adhesive 35. The adhesive 35 is obtained by melting and curing NCF (non-contact film) by heat treatment.

  The other end 18b of the first conductor layer 18 protrudes into the opening of the second storage space 13 formed in the wiring board 2, and this end 18b faces the surface of the IC 31. The end 18b and the connection electrode 32 are individually connected in a one-to-one relationship. This connection is performed by a flip chip bonding process, and the end 18 b of the first conductor layer 18 and the IC 31 are fixed by an adhesive 36. This adhesive 36 is obtained by curing NCP (non-contact paste) by heat treatment.

  Further, as shown in FIG. 1, a common conductor layer 28 is formed by a part of the conductor layer 8 formed on the opposite surface 2a. A plurality of branch conductor layers 28a are branched from the common conductor layer 28, and each branch conductor layer 28a extends into the opening of the first storage space 12 of the wiring board 2, respectively. The branched conductor layer 28 a faces the surface 21 a of the support substrate 21. Each branched conductor layer 28a and the connection electrode 26 provided on the support substrate 21 are individually connected in a one-to-one relationship. This connection is performed by a flip chip bonding method, and the branch conductor 28a and the support substrate 21 are fixed by an adhesive 37 formed of NCF.

  As shown in FIG. 1, the other end 28 b of the common conductor layer 28 is connected to any one of the connection electrodes 33 of the IC 31. That is, the other end 28b of the common conductor layer 28 also extends into the second storage space 13, and this end 28b and any one of the connection electrodes 33 are opposed to each other. The part 28b and the connection electrode 33 are connected by a flip chip bonding method.

  Since the common conductor layer 28 is electrically connected to all of the plurality of second electrodes 24 provided on the support substrate 21, a large current may be applied to the common conductor layer 28. In this thermal head 1, although the area of the surface 21a of the support substrate 21 having the heat generating element 22 is small, the opposing surface 2a of the wiring board 2 has a large area. It is possible to form a wide area corresponding to the energization.

  As shown in FIG. 2, a plurality of other conductor layers 38 are formed by a part of the conductor layer 8 formed on the opposite surface 2 a of the wiring board 2. The other conductor layer 38 is not shown in FIG. A part of the other conductor layer 38 extends into the opening of the second storage space 13 and is individually connected to the connection electrode 33 provided on the surface of the IC 31 in a one-to-one relationship. This connection is also a flip chip bonding method, and the conductor layer 38 and the IC 31 are bonded by an adhesive 36 formed of NCP.

  As shown in FIG. 2, an insulating layer 41 is formed of a solder resist or the like on the opposite surface 2 a of the wiring board 2, and this insulating layer 41 is common to the conductor layer 8, that is, the first conductor layer 18. The electric conductor layer 28 and the other electric conductor layer 38 are covered. An insulating layer 42 is also formed on the other surface (lower surface in the drawing) of the wiring board 2 with a solder resist or the like, and the wiring pattern 9 is covered with the insulating layer 42. A heat radiating member 43 formed of aluminum, an aluminum alloy, or the like is joined to the lower portion of the insulating layer 42, and heat generated by the heat generating element 22 is released from the heat radiating member 43 through the support substrate 21.

  FIG. 2 shows a state in which the thermal head 1 faces the ink ribbon 51 and the printing paper 52.

  In the thermal head 1, a support substrate 21 and an IC 31 are housed in the first housing space 12 of the wiring board 2, and a heating element 22 projects from the facing surface 2 a of the wiring board 2. On the other hand, the IC 31 is housed in the second housing space 13 of the wiring board 2 and no part of the IC 31 protrudes from the facing surface 2a, and the heating element 22 protrudes from the facing surface 2a. Only. The top 22a of the heating element 22 is located away from the facing surface 2a of the wiring board 2 and the surface of the insulating layer 41, and also away from the IC 31.

  Therefore, when the thermal head 1 is mounted on a thermal transfer printer or the like, the top 22a of the heating element 22 is not attached to the ink ribbon even if the facing surface 2a of the wiring board 2 is arranged parallel to the surface of the ink ribbon 51. 51, and other parts such as the IC 31 do not contact the ink ribbon 51 at this time. By bringing the top 22a of the heating element 22 and the ink ribbon 51 into contact, the contact area between the heating element 22 and the ink ribbon 51 can be minimized. Further, since the top portion 22a generates heat to the highest temperature, the heat at the heat generation point in the heating element 22 can be efficiently applied to the ink ribbon 51.

  However, even if a part of the IC 31 protrudes from the facing surface 2a, the top 22a of the heating element 22 is located farther from the facing surface 2a than the protruding end of the IC 31. As described above, when the facing surface 2a is arranged in parallel with the ink ribbon 51, the top portion 22a of the heating element 22 can come into contact with the ink ribbon 51, and the IC 31 does not interfere with the ink ribbon 51 or the like. .

  In the printing operation, the IC 31 selects any one of the plurality of first conductor layers 18 and applies a current, and this current passes through the heating element 22 from the first electrode 23 formed on the support substrate 21. , From the second electrode 24 to the common conductor layer 28. The heating element 22 generates heat at a portion facing the first electrode 23 to which a current is applied, and this portion becomes a heat generation point. With this heat, the ink on the ink ribbon 51 is melted and transferred to the printing paper 52. When the number of heat generated at the heat generation point of the heat generator 22 becomes large, the current applied to the large number of first conductor layers 18 also flows to the single common conductor layer 28. Therefore, a large current flows through the common conductor layer 28. However, since the common conductor layer 28 can be formed in a wide area on the opposite side 2a of the wiring board 2, it can withstand the supply of a large current.

  Therefore, the surface 21a of the support substrate 21 having the heating element 22 may be an area where the heating element 22, the first electrode 23, and the second electrode 24 can be formed, and it is not necessary to use a large-sized substrate. Further, the support substrate 21 formed of an expensive material such as a ceramic material can be formed at a low cost.

  The thermal head 1 is not limited to the one that faces the ink ribbon 51. For example, if the printing paper 52 itself can be colored by heat, the top portion 22a of the heating element 22 directly contacts the printing paper 52. You may let them.

Next, an example of the manufacturing process of the thermal head 1 according to the first embodiment will be described.
In the first step shown in FIG. 3, a concave portion 101 that is recessed from the surface 100a is formed on a dummy substrate 100 made of a metal plate such as a stainless steel plate. Further, the conductor layer 8 is formed on the surface 100a by a plating process. With this conductor layer 8, the first conductor layer 18, the common conductor layer 28, and the other conductor layers 38 are formed to have the pattern shown in FIG. In the manufacturing process of the conductor layer 8, a copper plating base layer is formed on the surface 100a of the dummy substrate 100 by sputtering or electroless plating. A nickel layer is plated thereon, and gold is further plated on the surface.

  The patterns of the first conductor layer 18, the common conductor layer 28, and the other conductor layers 38 can be realized by previously forming a plating base layer in the pattern shown in FIG. Alternatively, a resist layer is formed on the surface 100a of the dummy substrate 100, this resist layer is exposed and developed, and the resist layer is removed at the pattern portion of the conductor layer shown in FIG. 1, and the resist layer is removed. The portion may be plated.

  In the process shown in FIG. 4, the support substrate 21 is attached to the dummy substrate 100. A heating element 22 is formed by sintering on the surface 21 a of the support substrate 21, and a first electrode 23 and a second electrode 24 are formed. A connection electrode 25 is formed on the surface of the first electrode 23, and a connection electrode 26 is formed on the surface of the second electrode 24. The support substrate 21 is attached so that the surface 21 a faces the surface 100 a of the dummy substrate 100 and a part of the heating element 22 is accommodated in the recess 101. Then, the connection electrode 25 and one end portion 18a of the first conductor layer 18, and the connection electrode 26 and the branch electrode layer 28a of the common conductor layer 28 are bonded to each other by a flip chip bonding method that applies ultrasonic waves. .

  The IC 31 is mounted on the dummy substrate 100 either at the same time as attaching the support substrate 21 or before or after that. At this time, the connection electrode 32 provided on the IC 31 and the other end 18b of the first conductor layer 18 and the connection electrode 33 and the other conductor layer 38 are joined by a flip chip bonding method.

  NCF adhesives 35 and 37 are interposed in advance between the surface 100a of the dummy substrate 100 and the support substrate 21, and an NCP adhesive 36 is interposed between the surface 100a of the dummy substrate 100 and the IC 31. Apply. Then, the adhesives 35 and 37 and the adhesive 36 are melted and cured by heat treatment, and the support substrate 21 and the IC 31 are fixed to the surface 100 a of the dummy substrate 100.

  In the step shown in FIG. 5, another dummy substrate 102 facing the dummy substrate 100 is used. The dummy substrate 102 is formed of a metal plate such as a stainless steel plate, and the wiring pattern 9 is formed on the surface 102a by a plating process.

  In the process shown in FIG. 5, the wiring substrate 2 is sandwiched between the dummy substrate 100 and the dummy substrate 102. In this wiring board 2, film-like soft crimp substrates 4 and 5 made of glass epoxy prepreg material are laminated on both surfaces of a core substrate 3 on which wiring patterns 6 and 7 are formed on both sides. Is. In addition, a hole penetrating the wiring board 2 is filled with a conductor 11 made of a conductive adhesive before curing. The wiring board 2 is formed with a first storage area 12 and a second storage area 13 that penetrate therethrough.

  In the process shown in FIG. 6, the wiring board 2 is sandwiched between the dummy board 100 and the dummy board 102, and the dummy board 100 and the dummy board 102 are heated and the wiring is made between the dummy boards 100 and 102. The substrate 2 is pressurized. At this time, the support substrate 21 is stored in the first storage space 12 of the wiring substrate 2, and the IC 31 is stored in the second storage space 13 of the wiring substrate 2.

  By the heating and pressurization, the pressure-bonded substrates 4 and 5 are cured, and the pressure-bonded substrates 4 and 5 and the core material substrate 3 are firmly bonded. At the same time, the conductor layer 8 formed on the surface 100 a of the dummy substrate 100, that is, the first conductor layer 18, the common conductor layer 28, and the other conductor layer 38 are fixed to the surface of the pressure-bonding substrate 4. The Further, the wiring pattern 9 formed on the surface 102 a of the dummy substrate 102 is fixed to the surface of the pressure-bonding substrate 5. In addition, the conductor 11 filled in the through hole of the wiring board 2 is cured, and this conductor 11 is fixed to the first conductor layer 18, the common conductor layer 28 and the other conductor layer 38. The conductor 11 is fixed to the wiring pattern 9.

  In the process of FIG. 7, the dummy substrate 100 and the dummy substrate 102 are peeled from the wiring substrate 2. As a result, the first conductor layer 18, the common conductor layer 28, and the other conductor layer 38 are peeled off from the dummy substrate 100 while being fixed to the crimp substrate 4 and the conductor 11, and the wiring pattern 9 is also In a state of being fixed to the crimping substrate 5 and the conductor 11, it is peeled off from the dummy substrate 102.

  In the process of FIG. 7, the sealing material 27 is filled in the first storage space 12 to fix the support substrate 21 and the wiring substrate 2, and the sealing material 34 is stored in the second storage space 13. The IC 31 and the wiring board 2 are fixed.

  Thereafter, in the step shown in FIG. 8, a solder resist is applied to the opposite surface 2a of the wiring board 2 to form an insulating layer 41, and a solder resist is applied to the other surface of the wiring board 2 to form an insulating layer 42. Is done. Thereafter, the wiring board 2 is fixed to the heat dissipation member 43.

  In the above manufacturing process, the supporting substrate 21 can be accommodated in the first accommodation space 12 of the wiring board 2 and the IC 31 can be accommodated in the second accommodation space 13 by the plating process or the thermocompression bonding process. The end portion 18 a of the first conductor layer 18 and the branch conductor layer 28 a of the common conductor layer 28 can be formed in the opening of the first storage space 12. The end 18 b and the end 38 a of the other conductor layer 38 can be formed in the opening of the second storage space 13.

FIG. 9 is a sectional view showing a thermal head 201 according to the second embodiment of the present invention.
A thermal head 201 shown in FIG. 9 has a wiring board 202. The wiring board 202 has a bottomed first storage space 212 formed in a concave shape from the opposing surface (one surface) 202a and a similar bottomed and concave second storage space 213. ing. The wiring board 202 is formed of a glass epoxy prepreg material. Alternatively, as in the first embodiment, the wiring board 202 is formed by laminating the pressure-bonding boards 4 and 5 made of glass epoxy prepreg on both surfaces of the core board 3.

  In the first storage space 212, the support substrate 21 having the heating element 22 is stored, and the heating element 22 is positioned so that the top portion 22a of the heating element 22 is away from the facing surface 202a of the wiring board 202. 22 protrudes from the opposite surface 202a. Further, the IC 31 which is an electronic element is accommodated in the second accommodation space 213, and no part of the IC 31 protrudes from the opposing surface 202a.

  In the thermal head 201, as in the first embodiment shown in FIG. 1, a plurality of first conductor layers 18 are formed on the opposing surface 202a of the wiring board 202. One end 18a of the first conductor layer 18 extends into the opening of the first storage space 212, faces the surface 21a of the support substrate 21, and ends with the connection electrode 25 provided on the support substrate 21a. The parts 18a are individually connected so as to be one-to-one. The other end 18b of the first conductor layer 18 extends into the opening of the second storage space 213 and faces the IC 31, and each end 18b is connected to the IC 31. The electrodes 32 are individually connected in a one-to-one relationship.

  A common conductor layer 228 and a plurality of branch electrode layers 228a branched from the common conductor layer 228 are formed on the opposite surface 202a of the left side portion of the wiring board 202 in the figure. Each branch electrode layer 228a extends into the opening of the first storage space 212 and is individually connected to the connection electrode 26 provided on the surface 21a of the support substrate 21 in a one-to-one relationship. The first conductor layer 18 and the common conductor layer 228 are covered with an insulating layer 41.

  A common wiring pattern 328 is provided on the back surface (the other surface) of the wiring substrate 202. On the left side of the wiring substrate 202 in the figure, a conductor 211 is provided in a hole penetrating the wiring substrate 202, and the common conductor layer 228 and the common wiring pattern 328 are electrically connected by the conductor 211.

  On the right side of the wiring substrate 202 in the figure, a base-side common conductor layer 428 is formed on the facing-side surface 202a, and a part of the base-side common conductor layer 428 extends into the opening of the second storage space 213. The base side common conductor layer 428 and one of the connection electrodes 33 of the IC 31 are connected. A conductor 311 filled in a through hole is provided on the right side of the wiring board 202 in the figure, and the base-side common conductor layer 428 and the common wiring pattern 328 are connected to each other by the conductor 311. Yes.

  The common wiring pattern 328 is formed in a region that passes below the first storage space 212 and overlaps the support substrate 21. The common wiring pattern 328 is a single pattern, but can be formed in a wide area on the back surface of the wiring substrate 202. Therefore, a relatively large current can be applied to the common wiring pattern 328. The common wiring pattern 328 is formed below the first storage space 212 in a region that does not protrude from the first storage space 212 in the direction perpendicular to the paper surface of FIG. Even if formed in this way, the common wiring pattern 328 can have a large area. Therefore, as shown in FIG. 1, the area of the wiring board 202 is made smaller on the opposite surface 2 a of the wiring board 2 than in the configuration in which the common conductor layer 28 is routed to the side of the first storage space 12. it can.

  As shown in FIG. 9, the common wiring pattern 328 is covered with the insulating layer 42 on the back surface of the wiring board 202, and the wiring board 202 is fixed on the heat dissipation member 43.

  In the second embodiment, the first conductor layer 18 is formed on the opposite-side surface 202a of the wiring board 202. A wiring pattern that is electrically connected to the first conductor layer 18 is formed on the wiring board 202. May be formed on the back surface of the support substrate 21 and may pass through the lower side of the support substrate 21. Alternatively, at least one of the common wiring pattern 328 and the wiring pattern electrically connected to the first conductor layer 18 may be formed inside the thickness of the wiring board 202.

The fragmentary top view which shows the thermal head of embodiment of this invention, Longitudinal section of thermal head, Sectional drawing which shows the manufacturing method of the said thermal head, and shows the state in which the conductor layer was formed in the dummy substrate, A sectional view showing a manufacturing method of the thermal head, showing a state where a supporting substrate and an IC are mounted on a dummy substrate, Sectional drawing which shows the manufacturing method of the said thermal head, and shows the state by which the wiring board was pinched | interposed between the dummy board | substrate and a dummy board | substrate, Sectional drawing which shows the manufacturing method of the said thermal head, and shows the state by which the wiring board was crimped | bonded between the dummy board | substrate and the dummy board | substrate, Sectional drawing which shows the manufacturing method of the said thermal head, and shows the state which peeled the dummy substrate from the wiring board, Sectional drawing which shows the manufacturing method of the said thermal head, and shows the state by which the insulating layer was formed in the wiring board, Sectional drawing which shows the thermal head of the 2nd Embodiment of this invention,

Explanation of symbols

1 Thermal head 2 Wiring board 2a Opposite surface (one surface)
3 Core material substrates 4, 5 Crimp substrates 6, 7, 9 Wiring pattern 8 Conductor layer (wiring pattern)
18 First conductor layer 28 Common conductor layer 38 Other conductor layer 11 Conductor 12 First storage space 13 Second storage space 21 Support substrate 22 Heating element 22a Top 23 First electrode 24 Second Electrode 25, 26 Connection electrode 27 Sealing material 31 IC (electronic element)
32, 33 Connection electrode 35 Sealing material 41, 42 Insulating layer 43 Heat dissipation member 51 Ink ribbon 52 Printing paper 100, 102 Dummy substrate 201 Thermal head 211, 311 Conductor 228 Common conductor layer 328 Common wiring pattern 428 Base side common conductivity Body layer

Claims (13)

In a thermal head having a support substrate, a heating element provided on a surface of the support substrate, an electronic element that drives and controls the heating element, and a wiring board on which the support substrate and the electronic element are mounted.
A plurality of through holes or concave storage spaces are formed on one surface side of the wiring substrate, the support substrate is stored in any of the storage spaces, and the heating element protrudes from one surface of the wiring substrate. A thermal head characterized in that the electronic element is housed in another housing space.   The electronic element does not protrude from one surface of the wiring board, or even if the electronic element protrudes from the one surface, the top of the heating element is more than the protruding side end of the electronic element. The thermal head according to claim 1, wherein the thermal head is located away from one surface of the wiring board.   A plurality of electrodes connected to the heating element are provided on the surface of the supporting substrate having the heating element, and a conductor layer provided on one surface of the wiring board overlaps the surface of the supporting board. The thermal head according to claim 1, wherein the thermal head extends to a distance between the electrode and the conductor layer.   The said conductor layer provided in one surface of the said wiring board is extended to the position facing the electrode of the said electronic element, and the electrode of the electronic element and the said conductor layer are connected. Thermal head. On the surface of the support substrate, a plurality of first electrodes connected to one side of the heating element and a plurality of second electrodes connected to the other side of the heating element are formed, The heating element located between the first electrode and the second electrode can be partially heated,
The wiring board is provided with a plurality of first conductor layers individually connected to the plurality of first electrodes and a common conductor layer electrically connected to the plurality of second electrodes. 5. The thermal head according to claim 3, wherein the first electrode, the second electrode, and the electronic element are connected via the first conductor layer and the common electrode layer. 6.   The thermal head according to claim 5, wherein both the first conductor layer and the common conductor layer are formed on one surface of the wiring board.   6. The thermal head according to claim 5, wherein at least one of the first conductor layer and the common conductor layer passes through the other surface of the wiring board or the inside of the wiring board.   8. The thermal head according to claim 7, wherein one of the first conductor layer and the common conductor layer passes through the other surface of the wiring board or the inside of the wiring board and a region overlapping with the support board.   The thermal head according to claim 4, wherein an insulating layer that covers the conductor layer is provided on one surface of the wiring board.   The thermal head according to claim 1, wherein the support substrate is formed of any one of a ceramic material, a glass material, and a metal material. (A) forming a conductor layer on the surface of a dummy substrate having holes or recesses;
(B) A support substrate provided with a heating element on the surface and an electrode connected to the heating element is opposed to the surface of the dummy substrate, and the heating element is inserted into the hole or recess, Connecting the conductor layer to face each other;
(C) simultaneously or before and after the step (b), connecting an electronic element for driving and controlling the heating element to the conductor layer;
(D) A wiring board on which through holes or a plurality of concave storage spaces are formed is installed on the surface of the dummy substrate, the support substrate is stored in one of the storage spaces, and the electronic element is stored in another storage space. And fixing the conductor layer to the surface of the wiring board;
(E) peeling the dummy substrate from the conductor layer fixed to the wiring substrate;
A method of manufacturing a thermal head, comprising: After the step (d),
The method of manufacturing a thermal head according to claim 11, further comprising a step of covering the conductor layer provided on the surface of the wiring board with an insulating layer.   The method of manufacturing a thermal head according to claim 11, wherein the wiring board is a prepreg material, and the wiring board is thermocompression bonded to the dummy board in the step (d).

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