JPH0516408A - Thermal head - Google Patents

Abstract

PURPOSE:To prevent a flexible printed circuit board from twisting which is prone to take place in the assembling process. CONSTITUTION:In a thermal head 9, a driving circuit is positioned at the lateral side of a heat sink having a head substrate mounted to the end face thereof. An insulating member 12 is provided at the side face of the heat sink 11 in order to prevent the shortcircuit of the heat sink 11 and a flexible printed circuit board 15 and to position the printing circuit board 15. The insulating member 12 has a supporting projecting part 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end face type thermal head for printing on a prepaid card or the like.

[0002]

2. Description of the Related Art At present, various types of printers have been put into practical use, for example, thermal printers for printing on prepaid cards and the like. Therefore, as a conventional example of a thermal head used in such a thermal printer, an apparatus disclosed in Japanese Patent Laid-Open No. 1-21791 will be described with reference to FIG. First, this thermal head 1
In the above, a slender head substrate 3 is attached to the upper end surface of a heat dissipation plate 2 formed in an L shape in the main scanning direction, and a large number of heating resistors 4 are continuously arranged in the main scanning direction on the head substrate 3. ing. On the other hand, in this thermal head 1, a circuit board 5 is attached to a side surface portion corresponding to the concave portion of the heat dissipation plate 2, and a driver IC (Integrated Circuit) 6 which is a drive circuit mounted on the circuit board 5 is installed. It is covered with a cover member 7. In the thermal head 1, the electrodes (not shown) of the heating resistor 4 formed on the side edge of the head substrate 3 and the driver IC 6 formed on the upper edge of the circuit board 5 are arranged. FPC (Flexible Printed) in which the electrodes are flexible printed wiring boards
It is connected by Circuit 8).

Then, for example, a platen roller is arranged to face the heating resistor 4 of the thermal head 1 as described above via a conveyance path of a recording medium such as printing paper or an ink ribbon, and a printer controller is provided in the driver IC 6. A thermal printer (not shown) is formed by being connected.

In such a structure, in the thermal head 1, drive power is applied to the heating resistor 4 by selectively switching the driver IC 6 according to the input print data, and this heating resistor 4 is applied. The recording medium is conveyed by the rotation of the platen roller in synchronism with the heat generation scanning of No. 4, so that image printing is performed on the recording medium by fusing of ink or heat-sensitive color development.

Here, in this thermal head 1, the circuit board 5 on which the driver IC 6 is mounted as described above is arranged on the side surface of the heat dissipation plate 2 as a separate body from the head substrate 3 on which the heating resistor 4 is formed. This shortens the length in the sub-scanning direction of the portion of the recording medium on the conveying path, and prevents the driver IC 6 and the like from interfering with the conveying path of the recording medium. By doing so, the thermal head 1 can print on a recording medium that cannot be bent, such as a prepaid card.

[0006]

In the thermal head 1 described above, in order to shorten the whole in the sub-scanning direction and facilitate the conveyance of the recording medium, the heads are attached to each of the end surface and the side surface of the heat dissipation plate 2. The board 3 and the circuit board 5 are connected by an FPC 8.

However, in the thermal head 1 having the above-described structure, when each member is assembled to the heat sink 2, a flexible F
There is a concern that the PC 8 may be twisted, causing disconnection or connection failure.

Further, in the above-mentioned thermal head 1, there is a concern that the recording medium conveyed to the FPC 8 mounted on the head substrate 3 may actually collide, so that the FPC 8 is covered with a protective cover (not shown). However, the thermal head 1 described above does not have a portion where such a protective cover can be easily attached.

Further, in the above-mentioned thermal head 1,
In order to connect the driver IC 6 to the heating resistor 4, the circuit board 5 is attached to the head substrate 3 and the flexible printed wiring board 8 is attached.
Since the structure is connected by, the number of parts and the number of processes are increased and the productivity is decreased.

The present invention provides a thermal head in which the flexible printed wiring board is prevented from being easily twisted when each member is assembled to a heat dissipation plate, and the mounting accuracy of each member is good.

The present invention also provides a small and lightweight thermal head which has a reduced number of thermal head components and has good productivity.

Further, the present invention provides a thermal head in which a protective cover covering a connecting portion between the head substrate and the flexible printed wiring board can be easily attached.

[0013]

The invention according to claim 1 is
An elongated head substrate is attached to the end surface of the heat sink in the main scanning direction, and a large number of heating resistors each having electrodes formed in the sub-scanning direction are continuously arranged on the head substrate in the main scanning direction. In the thermal head in which the drive circuit is located and the drive circuit is connected to the electrodes of the head substrate with the flexible printed wiring board, the supporting protrusions for positioning the both side edges of the flexible printed wiring board are provided with insulating members protruding from the both sides. It was attached to the side of the heat sink.

According to a second aspect of the present invention, an elongated head substrate is attached to the end surface of the heat dissipation plate in the main scanning direction, and a large number of heating resistors each having electrodes formed in the sub scanning direction are provided on the head substrate. In a thermal head in which the drive circuit is located on the side of the heat sink, the printed wiring board is connected to the head substrate, and the supporting projections that position both side edges of this flexible printed wiring board project to both sides. The installed insulating member was attached to the side surface of the heat sink, and the mounting component of the drive circuit was attached to the back surface of the flexible printed wiring board separated from the side surface of the heat sink by the insulating member.

According to the third aspect of the present invention, the protective cover covering the connecting portion between the head substrate and the flexible printed wiring board is mounted on the supporting convex portion of the insulating member.

[0016]

According to the first aspect of the present invention, since both side edges of the flexible printed wiring board are positioned by the supporting convex portions of the insulating member attached to the side surface of the heat sink, the flexible structure is provided when the respective members are assembled to the heat sink. Twisting, which is likely to occur in the printed wiring board, is prevented.

According to a second aspect of the present invention, the flexible printed wiring board is mounted on the back surface of the flexible printed wiring board separated from the side surface of the heat dissipation plate by an insulating member, so that the flexible printed wiring board can be used as a head substrate and a circuit board. The number of parts is reduced and the space efficiency is very good as compared with the case of using only for connection.

According to the third aspect of the present invention, the protective cover covering the connecting portion between the head substrate and the flexible printed wiring board is mounted on the supporting convex portion of the insulating member, so that the protective cover can be easily mounted.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention described in claim 1 will be described with reference to FIGS. First, in the thermal head 9, as illustrated in FIG. 1, an insulating member 12 made of resin, ceramics, or the like is provided on a side surface of a rectangular parallelepiped radiator plate 11 having a head substrate 10 elongated in the main scanning direction attached to an end surface thereof. Circuit boards 13 and 14 are sequentially attached, and the head board 10 and the circuit board 13 are connected by an FPC 15 which is a flexible printed wiring board.

Here, as illustrated in FIG. 2, in the head substrate 10, the inclined flat surface portion 17 is continuous with the flat surface portion 16 projecting from the front half portion in the sub-scanning direction. The flat portion 18 parallel to the flat portion 16 is continuous. Here, each of the flat portions 16 to 18 is extended in the main scanning direction of the head substrate 10, and the heating resistor 19 is formed on the projected flat portion 16 to form the flat portion 1.
7, a common electrode 20 and an individual electrode 21 are formed, and the terminal portion 2 of the electrodes 20, 21 is formed on the plane portion 18.
2, 23 is formed.

A specific example of the structure and manufacturing method of the head substrate 10 will be described below. First, a large number of head substrates 10 are obtained by molding a large-sized substrate that has already been manufactured, and the glass glaze layer 24 is formed on the flat surface portion 16 of the head substrate 10 by the existing thin film technique and washed. And
After that, a Ta—SiO ₂ layer to be the heating resistor 19 and an Al layer to be the electrodes 20 and 21 are sequentially formed on the entire surface of the head substrate 10 by sputtering or the like, and these thin film layers are patterned by a photolithography process. The heating resistor 19 and the electrodes 20 and 21 are formed. Then, by forming the protective film 25 on the flat portion 16 by the existing thin film technology so as not to cover the terminal portions 22 and 23 of the electrodes 20 and 21,
This head substrate 10 is formed.

On the other hand, the circuit boards 13 and 14 have electrodes 26 and 27 continuously provided at the upper edges by printed wiring or the like, and the driver IC 28, which is a mounted component of the drive circuit mounted on the circuit board 13, is Bonding wires 29 are connected to the electrodes 26 and 27.

In this thermal head 9, the electrodes 22, 23, 2 of the head substrate 10 and the circuit substrate 13 are
6, the FPC 15 is joined by thermocompression bonding of the anisotropic conductive film 30, and the FPC 15 is connected to the insulating member 1
It is insulated from the heat dissipation plate 11 by 2. Here, the insulating member 12 has supporting projections 31 projecting from both sides thereof, and these supporting projections 31 position both side edges of the FPC 15.

Then, as illustrated in FIG. 3, the platen roller 3 is provided on the heating resistor 19 of the thermal head 9 having the above-described structure via the conveyance path of the recording medium 32 such as thermal paper.
By disposing 3 facing each other, an end surface type thermal printer 3
4 is formed.

In this structure, in the thermal printer 34, the driver IC 28 is selectively switched according to the print data input from the printer controller (not shown) connected to the circuit board 14. Driving power is applied to the heating resistor 19, and the recording medium 32 is conveyed by the rotation of the platen roller 33 in synchronization with the heating scan of the heating resistor 19.
Image printing is performed on the second layer by ink welding or heat-sensitive color development.

Here, one specific example of the method of assembling the thermal head 9 will be described with reference to FIG. First, the same figure
As illustrated in (a), the terminal portion 22 of the head substrate 10,
23. One edge of the FPC 15 is attached to 23 by thermocompression bonding of the anisotropic conductive film 30, and as shown in FIG.
The other edge of C15 is attached to the electrode 26 of the circuit board 13 by thermocompression bonding of the anisotropic conductive film 30. Therefore, the same figure (c),
As illustrated in (d), the members 10, 13, 15 integrated in this way are mounted on the heat dissipation plate 11 to which the insulating member 12 is attached in advance, and as illustrated in FIG. By mounting the circuit board 14 under the circuit board 13 and connecting the bonding wires 29, the assembly of the thermal head 9 is completed. By doing so, in the thermal head 9, the members 10, 1 integrated as described above are provided.
Since both edges of the FPC 15 are positioned by the supporting protrusions 31 of the insulating member 12 when the heat sinks 3 and 15 are mounted on the heat sink 11, the head substrate 10 and the circuit substrate 13 can be mounted with good accuracy.

Another specific example of the method of assembling the thermal head 9 will be described with reference to FIG. First, the same figure
As illustrated in (a), the terminal portion 22 of the head substrate 10,
23. One edge of the FPC 15 is attached to the 23 by thermocompression bonding of the anisotropic conductive film 30, and the head substrate 10 is attached to the heat radiating plate 1 to which the insulating member 12 is attached in advance, as illustrated in FIG.
Attach to the end face of 1. Then, as illustrated in FIG. 1C, the circuit board 13 is attached to the side surface of the heat dissipation plate 11 so as to contact the insulating member 12 from below, and as illustrated in FIG. The FPC 15 is attached to the electrode 26 of 13 by thermocompression bonding of the anisotropic conductive film 30. And
After that, the circuit board 14 is mounted under the circuit board 13 and the bonding wires 29 are connected in the same manner as in the assembly method described above, whereby the assembly of the thermal head 9 is completed. By doing so, in this thermal head 9, the circuit board 13 mounted on the heat dissipation plate 11 is positioned by the insulating member 12, so that the mounting accuracy is good.
Also, the FPC 15 mounted on the base plate has good mounting accuracy because both edges are positioned by the supporting projections 31 of the insulating member 12.

That is, in this thermal head 9, when the respective members are assembled to the heat dissipation plate 11, the insulating member 12 causes the F
Since the PC 15 is prevented from being twisted, the mounting accuracy of each member is good.

The side surface of the heat dissipation plate 11 referred to here is
It means one of the four surfaces that are orthogonal to the end surface on which the head substrate 10 is mounted, and does not relate to the front, rear, left, and right directions or the conveyance direction of the recording medium 32. Further, in this thermal head 9, there is a concern that the thin film members 19 to 21 manufactured on the flat surface portions 16 to 18 having steps may be broken. When the head substrate 10 was prototyped by setting the width in the sub-scanning direction of 16 and the level difference between the positions where the thin film members 19 to 21 were formed to various values, the inclination angle of the flat portion 17 was set to 60 degrees or less or the flat portion 16 It has been found that the thin film members 19 to 21 are favorably formed by setting the step between the flat portion 18 and the flat portion 18 to be 1.0 (mm) or less.

Further, an embodiment of the invention described in claim 2 will be described with reference to FIG. First, this thermal head 35
Then, the FPC 36 connected to the head substrate 10 is connected to the circuit board 14 without the circuit board 13 interposed therebetween, and the driver IC 28 is provided on the back surface of the FPC 36 separated from the heat sink 11 by the circuit board 14 and the insulating member 12. Has been implemented. The driver IC 28 and the F
The connecting portion between the PC 36 and the head substrate 10 is covered with a sealing material 37 such as resin, and the other structure is similar to that of the thermal head 9 described above.

In this structure, the thermal head 35 has the FPC 36 connected to the head substrate 10.
Since the driver IC 28 is mounted on the back surface of the device, the number of parts thereof is reduced and the productivity is good. Moreover, in the thermal head 35, the driver IC 28 is provided on the back surface of the FPC 36 separated from the heat sink 11 by the insulating member 12.
Since the space is arranged, the space efficiency is extremely good and it is easy to reduce the size and weight.

Further, an embodiment of the invention described in claim 3 will be described with reference to FIG. First, this thermal head 38
Then, a protective cover 39 bent in an L shape is attached to the tip end surface of the support convex portion 31 of the insulating member 12, and the connection portion between the head substrate 10 and the FPC 15 is covered with the upper portion of the protective cover 39. The driver IC 28 is covered at the bottom. The other structure is similar to that of the thermal head 9 described above.

In such a structure, in the thermal head 38, the protective cover 39 and the head substrate 10 and the FP
Since it covers the connection with the C15, here is the recording medium 3
2 is prevented from colliding. Further, in this thermal head 38, since the driver IC 28 is also covered with the protective cover 39, it is possible to prevent a short circuit from occurring due to dust attached to the driver IC 28 and the bonding wire 29. Moreover, in the thermal head 38, since the protective cover 39 as described above is attached to the tip end surface of the supporting convex portion 31 of the insulating member 12, its implementation is easy and the productivity is good.

[0034]

According to the first aspect of the invention, a long and narrow head substrate is attached to the end surface of the heat dissipation plate in the main scanning direction, and a large number of heating resistors each having an electrode formed in the sub scanning direction are formed on the head substrate. Supports for positioning both side edges of the flexible printed wiring board in a thermal head in which the driving circuit is placed side by side in the scanning direction, the driving circuit is located on the side of the heat sink, and this driving circuit is connected to the electrodes of the head board with the flexible printed wiring board. By attaching the insulating member with the protrusions protruding from both sides to the side surface of the heat sink, further twisting that easily occurs in the flexible printed wiring board when assembling each member to the heat sink is supported by the insulating member. Since it is prevented by the parts, the mounting accuracy of each member is good, and there is an effect that it can contribute to the improvement of the productivity of the device.

According to a second aspect of the present invention, an elongated head substrate is attached to the end surface of the heat dissipation plate in the main scanning direction, and a large number of heating resistors each having electrodes formed in the sub scanning direction are provided on the head substrate. In a thermal head in which the drive circuit is located on the side of the heat sink, the printed wiring board is connected to the head substrate, and the supporting projections that position both side edges of this flexible printed wiring board project to both sides. By mounting the installed insulating member on the side surface of the heat sink and by mounting the components of the drive circuit on the back surface of the flexible printed wiring board separated from the side surface of the heat sink by this insulating member, the flexible printed wiring board can be used as the head substrate. Since the number of parts is reduced compared to the case where it is used only for connection to a circuit board, it can contribute to improving the productivity of the equipment, and further, the insulating member can be used. Since the mounting components are located in the space formed between the heat sink and the flexible printed wiring board, the space efficiency is extremely good, and it is possible to contribute to the reduction in size and weight of the device. .

According to the third aspect of the present invention, the protective cover covering the connecting portion between the head substrate and the flexible printed wiring board is attached on the supporting convex portion of the insulating member, so that the protective cover covers the head substrate and the flexible printed wiring. It is possible to prevent the recording medium from colliding with the connecting portion with the substrate and to easily attach the protective cover to the tip end surface of the supporting convex portion of the insulating member, which facilitates the implementation and improves the productivity. It has certain effects.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the invention described in claim 1.

FIG. 2 is a vertical sectional side view of a main part.

FIG. 3 is a side view showing a thermal printer.

FIG. 4 is a process chart showing an example of a manufacturing method.

FIG. 5 is a process drawing showing an example of a manufacturing method.

FIG. 6 is a side view showing an embodiment of the invention described in claim 2.

FIG. 7 is a side view showing an embodiment of the invention according to claim 3;

FIG. 8 is a perspective view showing a conventional example.

[Explanation of symbols]

9,35,38 Thermal head 10 head substrate 11 Heat sink 12 Insulation member 15,36 Flexible printed wiring board 19 Heating resistor 28 Mounted parts 31 Supporting convex part 39 Protective cover

Claims (3)

[Claims] 1. A head substrate elongated in the main scanning direction is attached to an end surface of a heat dissipation plate, and a large number of heating resistors each having electrodes formed in the sub scanning direction are continuously provided on the head substrate in the main scanning direction. In a thermal head in which a drive circuit is located on the side of a heat sink and the drive circuit is connected to an electrode of the head substrate by a flexible printed wiring board, support convex portions for positioning both side edges of the flexible printed wiring board are provided on both sides. A thermal head, characterized in that an insulating member protruding from the heat sink is attached to a side surface of the heat dissipation plate. 2. A head substrate elongated in the main scanning direction is attached to an end surface of a heat dissipation plate, and a large number of heating resistors each having electrodes formed in the sub scanning direction are continuously arranged on the head substrate in the main scanning direction. In a thermal head in which a drive circuit is located on the side of a heat dissipation plate, a printed wiring board is connected to the head substrate, and support projections for positioning both side edges of this flexible printed wiring board are provided on both sides of the insulating projection. A thermal head characterized in that a member is attached to a side surface of the heat dissipation plate, and a mounting component of the drive circuit is attached to a back surface of the flexible printed wiring board separated from the side surface of the heat dissipation plate by the insulating member. 3. The thermal head according to claim 1, wherein a protective cover covering a connecting portion between the head substrate and the flexible printed wiring board is mounted on a supporting convex portion of the insulating member.