JPH0712702B2 - Thermal head - Google Patents

Description

The present invention relates to a thermal head.

(B) Conventional Technique FIG. 4 is a side view showing a conventional thermal head.

In this thermal head, an insulating substrate 72 and a reinforcing plate 73 are placed on the upper surface of an aluminum heat dissipation plate 71, and heating dots 74 and a drive IC 75 are mounted on the wiring pattern of the insulating substrate 72.
Then, on the upper surface of the reinforcing plate 73, a flexible board 76 for external circuit connection, one end of which overlaps with the end of the wiring pattern, is provided, and the flexible board 76 is attached to the reinforcing board 73.
Is connected to the connector 77 provided on the lower surface of the. Furthermore, by disposing a pressure contact cover 79 having a silicone rubber 78 on the overlapping portion of the insulating substrate (wiring pattern) 72 and the flexible substrate 76, and fixing the pressure contact cover 79 to the reinforcing plate 73 with a screw 79a, The insulating substrate (wiring pattern) 72 and the flexible substrate 76 are pressed against each other.

(C) Problems to be solved by the invention The insulating substrate (ceramic substrate) of the thermal head has a dot connection pattern (not shown) for connecting the heating dots and the drive ICs, as well as each drive IC. Input signal patterns for connecting to the respective input signal terminals are formed. The conventional input signal wiring pattern 72a is the sixth
As shown in the diagram, each input signal terminal of each drive IC 75 (for example, data-in terminal, power supply terminal, clock signal terminal, ground terminal, strobe terminal, latch terminal,
Input signal patterns (signal wiring) 72a corresponding to the data-out terminals) 75a are individually formed. For this reason,
The flexible board 76 connected to the input signal pattern 72a also has a wiring pattern made up of a plurality of signal wires.
It is necessary to form 76a. However, IC75 for each drive
Wiring pattern 76a corresponding to the input signal pattern 72a individually drawn from each input signal terminal 75a
To be formed on the flexible substrate 76, it is necessary to wire so that the signal lines do not intersect. Therefore, conventionally, for example, through holes are formed in the flexible substrate 76, and the wiring pattern 76a is formed on both front and back surfaces.
The flexible board 76 becomes expensive. That is, there is a disadvantage that the thermal head becomes expensive.

The flexible substrate 76 is formed to have a length substantially similar to that of the insulating substrate 72, and is parallel to the heating dots 74.
Are pressed onto the input signal wiring pattern 72a in a superimposed manner. However, since there are many wiring connection points, as shown in FIG. 5, a large number of screws 79a must be fixed by pressure welding, which not only takes a long time for the pressure welding work, but also has a disadvantage that the pressure welding reliability is deteriorated. was there.

The present invention solves the above problems, and by connecting only both ends, it is possible to reduce the occurrence of warpage due to the difference in thermal expansion coefficient, etc., and a cheap thermal head with simple connection work and high connection reliability. The purpose is to provide.

(D) Means and Actions for Solving the Problem In order to achieve this object, the thermal head according to the first aspect has the following configuration.

That is, this thermal head is provided with a heating dot row along the first long side of an insulating substrate having a substantially rectangular shape in a plan view, and a plurality of drive ICs connected to the heating dot row on the insulating substrate are arranged. In a rectangular arrangement, the insulating substrate passes between the tip of the heating dot row and the short side of the insulating substrate at the end of the first long side, and A first common electrode formed up to the end of the second long side that opposes; a second common electrode formed in a strip shape along the second long side up to the vicinity of the end; Is formed between the common electrode of and the row of a plurality of drive ICs,
It is formed along the short side direction between the first common electrode and the second common electrode tip at the end of the second long side, and has a width narrower than that of the first and second common electrodes. It is configured by forming a plurality of wiring patterns.

In the thermal head having such a configuration, each input signal terminal (data-in terminal, power supply terminal, clock signal terminal) of each drive IC is formed by a plurality of wiring patterns (input signal wiring pattern) formed on the insulating substrate. , Ground terminal, strobe terminal, latch terminal, data-out terminal)
However, they are commonly connected. For example, each input signal terminal of each drive IC is connected to the input signal wiring pattern via wire bonding. Also,
At the second long side end (for example, both ends) of the insulating substrate, the first
Also, the second common electrode and a plurality of wiring patterns are extended. Therefore, for example, a connector (external circuit connecting terminal) may be connected to the lead-out terminals at the two long-side end portions. That is, not only does an expensive flexible board with double-sided wiring, which has a length similar to that of an insulating board and has signal lines corresponding to a large number of individually drawn input signal terminals, becomes unnecessary as in the conventional case, Therefore, the number of connection pressure contact points is extremely reduced, and the simplicity of the pressure contact work and the pressure contact reliability can be improved. Further, it becomes possible to directly connect the connector to the lead-out terminal led out to the second long-side end portion of the insulating substrate. In this case, soldering can be used instead of pressure contact.

The thermal head according to the second aspect has the following configuration.

That is, this thermal head has a substantially rectangular shape in plan view, and the heating dot row is provided along the first long side,
A plurality of drive ICs connected to this heating dot row are arranged in a row, and pass through between the tip of the heating dot row and the short side of the insulating substrate at the end of the first long side, A first common electrode formed up to the end of the second long side facing the first long side, and a second common formed along the second long side to the vicinity of the end in a strip shape. An electrode and between the second common electrode and a row of a plurality of drive ICs,
It is formed along the short side direction between the first common electrode and the second common electrode tip at the end of the second long side, and has a width narrower than that of the first and second common electrodes. An insulating substrate having a plurality of wiring patterns formed thereon; a glass epoxy substrate having a wiring pattern corresponding to a lead terminal formed at the end of the second long side of the insulating substrate on one surface; A wiring pattern corresponding to the lead-out terminal is provided on one side, and the one-sided flexible piece connects the lead-out terminal of the insulating substrate and the wiring pattern of the glass epoxy substrate.

In the thermal head having such a configuration, a glass epoxy substrate having a wiring pattern corresponding to the lead-out terminal of the insulating substrate on one side, and a lead-out terminal of the insulating substrate, the wiring pattern corresponding to the lead-out terminal of the insulating substrate on one side It is pressed with a single-sided flexible piece provided. The input signal wiring pattern of the insulating substrate is commonly connected to each input signal terminal of each drive IC, and the lead-out terminal of the signal input wiring pattern is the second long side end portion of the insulating substrate. (For example, both ends) are arranged so as to lead out. Therefore, the flexible piece
A small piece having a size corresponding to the lead-out terminal, that is, a size corresponding to the second long side end portions (both end portions) of the insulating substrate,
Moreover, an inexpensive one having a wiring pattern only on one side may be used. Further, this flexible piece only needs to be arranged corresponding to the lead-out terminals provided at both ends of the insulating substrate, and the number of pressure contacts for pressing the lead-out terminal and the glass epoxy substrate is sufficient. Therefore, not only the pressure welding work (pressure welding screw) can be reduced, but also the connection reliability is improved, and the strain which may occur during the pressure welding tightening (the screw tightening) can be reduced.

(E) Embodiment FIG. 1 is a specific embodiment of the thermal head according to the present invention, and is a plan view showing an embodiment of the thermal head described in claim 1 (first claim). It is a figure.

The thermal head substrate (insulating substrate) 1 has heating dots (dot rows) along the first long side (upper side in the figure) of one side.
11, a plurality of drive ICs (20 ICs in the embodiment) 2 are mounted. The insulating substrate 1 has a common pattern (first common electrode) 31 connected to the heating dots 11, a dot connection pattern (not shown) connecting the heating dots 11 to the drive IC 2, and each of the drive ICs 2. An input signal wiring pattern (a plurality of wiring patterns) 3 for connecting the input signal terminal 21 is formed.

In FIG. 1, each drive IC 2 has input terminals 21 for DI (data-in), 5V (power) terminal, CLK (clock signal) terminal, GND in addition to dot terminals.
Seven terminals (not shown) are formed: a (ground) terminal, a STR (strobe signal) terminal, an LA (latch signal) terminal, and a DO (data out) terminal.

On the other hand, in the input signal wiring pattern 3 of the insulating substrate 1, at the end of the first long side (upper side) of the insulating substrate 1, the leading end 11a of the heating dot 11 row and the short side of the insulating substrate 1 are formed. Pass through
A COM (common) pattern (first common electrode) 31 formed up to the end of the second long side (lower side) opposite to the first long side, and the COM (common) pattern 31 along the second long side. GND (earth) pattern (second common electrode) 3 formed in a strip shape near the edge 3
2, the ground pattern 32, and the plurality of drive ICs 2 are formed between the rows, and the common pattern is formed at the end of the second long side.
Insulating substrate 1 is provided between 31 and the tip 32a of ground pattern 32.
Common and earth pattern 3 formed along the short side of
A plurality of wiring patterns having a width narrower than 1,32 are provided. In this plurality of wiring patterns 3, 5V pattern, DI
Pattern, clock pattern and latch pattern are provided respectively, and strobe pattern is for each drive IC
It is arranged in a straight line so that the lower side of 2 is passed. Then, at the positions corresponding to the data-out terminal and the data-in terminal of the adjacent drive ICs 2, a data-in / out connection pattern for connecting the two is provided.

The input signal terminals 21 of the drive ICs 2 are connected to the corresponding input signal wiring patterns 3 by wire bonding. That is, the data-in terminal of the drive IC 2 located on the one end side of the insulating substrate 1 has a DI pattern of 5
V terminal is 5V pattern, clock terminal is CLK pattern,
The ground terminal is connected to the GND pattern, the strobe terminal is connected to the STR pattern, and the latch terminal is connected to the LA pattern by wire bonding. The data-out terminal is connected to the data-in / out pattern via wire bonding and is connected to the data-in terminal of the adjacent IC2.

In this way, the input signal pattern 3 of the insulating substrate 1 is formed as a common connection pattern for each input signal terminal 21 of each drive IC 2, and the lead end of this input signal pattern 3 is formed.
As shown in FIG. 1, 3A and 3B are arranged as lead terminals at the ends (both ends) of the second long side of the insulating substrate.

The lead-out terminal 3A is the second long side end (one end) of the insulating substrate 1.
Between the ground pattern 32 and the common pattern 31 in, 5V derivation terminal 33b, D1 derivation terminal 34b, CLK derivation terminal 35b,
The LA lead-out terminals 36b are arranged in this order. In addition, the lead-out terminal 3B
Between the ground pattern 32 and the common pattern 31 at the second long-side end (the other end) of the insulating substrate 1, the STR1 lead-out terminal 37b, the STR2 lead-out terminal 37c, the STR3 lead-out terminal 37d, and the STR4 lead-out terminal 37e. Are arranged in this order. This is set so that 20 drive ICs 2 are divided into 4 groups of 5 drive circuits and a strobe signal is input to each group (5 drive ICs).

In the thermal head having such a configuration, each input signal terminal of each drive IC 2 (data-in terminal, power supply terminal, clock signal terminal, ground terminal, strobe terminal,
Latch terminals, data-out terminals) are commonly connected by a common input signal wiring pattern 3 formed on the insulating substrate 1 via wire bonding. The lead-out terminals 3A and 3B of the common connection pattern 3 are separately arranged at the ends (both ends) of the second long side of the insulating substrate 1. Therefore, a connector may be directly connected to each drive IC 2, and data input from an external circuit may be directly input to the lead terminals 3A and 3B located at both ends of the IC. That is,
Not only does an expensive flexible board having double-sided wiring, which has the same length as the insulating board 1 and has signal lines corresponding to a large number of individually drawn input signal terminals as in the conventional case, is not required, The number of connection pressure contact points of the signal line is extremely reduced, and the ease of pressure contact work and the pressure contact reliability can be improved. Further, when the connector is directly connected to the lead-out terminals 3A and 3B, soldering can be performed instead of pressure contact.

FIG. 2 is an exploded plan view showing an embodiment of the thermal head described in claim 2 (second claim).

This thermal head has an insulating substrate 1 having the same configuration as the insulating substrate 1 shown in FIG. 1 and wiring patterns corresponding to the lead terminals 3A and 3B of this insulating substrate (input signal wiring pattern 3) 1 on one side. Two single-sided flexible pieces with
4, 4A, and a single-sided glass epoxy substrate 5 also provided on one side with a wiring pattern corresponding to the lead-out terminals 3A, 3B.

The single-sided flexible piece 4 has a size corresponding to the lead-out terminal 3A, and has a common line 41 connected to the common pattern 31 at one end, a 5V line 42 connected to the 5V lead-out terminal 33b, and a DI line 43 connected to the DI lead-out terminal 34b. , CLK line 44 connected to CLK derivation terminal 35b, LA line 45 connected to LA derivation terminal 36b,
And the GND line 46 connected to the ground pattern 32 at the other end
Is formed. Similarly, the single-sided flexible piece 4A is a piece having a size corresponding to the lead-out terminal 3B, and is connected to the ground line 41a connected to the ground pattern 32 at one end, the STR1 line 42a connected to the STR1 lead-out terminal 37b, and the STR2 lead-out terminal 37c. STR2
Line 43a, STR3 line 44 connected to STR3 lead-out terminal 37d
A STR4 line 45a connected to the STR4 lead-out terminal 37e and a common line 46a connected to the common pattern 31 are formed. Then, screw insertion holes 47, 47a for pressure contact are opened in the center of the surface of the one-sided flexible pieces 4, 4A.

The single-sided glass epoxy substrate 5 is the lead-out terminal 3A of the insulating substrate 1,
A wiring pattern 51 corresponding to the lead-out terminal 3B is provided on one surface, and signal lines starting from both ends are led out to the lead-out terminal 52 at the center of the length. In other words, the lead-out terminal 52 is in the figure (from the left side), COM terminal 52a, DI terminal 52b, 5V terminal 52c, CL
K terminal 52d, LA terminal 52e, GND terminal 52f, GND terminal 52g, STR1
Terminal 52h, STR2 terminal 52i, STR3 terminal 52j, STR4 terminal 52k, CO
M terminals 521 are arranged in order. And this lead-out terminal 52
Is connected to the connector 63.

In this thermal head, as shown in the side view of FIG. 3, the insulating substrate 1 and the glass epoxy substrate 5 are placed on the upper surface of the heat dissipation plate 61, and the lead-out terminals 3A, 3A of the insulating substrate (input signal pattern 3) 1, 3B and the signal wiring end faces located at both ends of the wiring pattern 51 of the glass epoxy substrate 5 are butted against each other, and the single-sided flexible strips 4 and 4A are superposed on the upper faces of the butted faces. The lead-out terminal 52 of the glass epoxy substrate 5 is connected to the connector 63. Then, the pressure contact cover 64 including the pressure contact rubber 62
Is put on the polymerized portion and pressed with screws 65. In other words, screw 65
Is fastened to the heat dissipation plate 61 via the screw insertion holes 47, 47a of the one-sided flexible pieces 4, 4A. Therefore, the connection between the signal input pattern 3 of the insulating substrate 1 and the wiring pattern 51 of the single-sided glass epoxy substrate 5 is only on one side of the lead-out terminals 3A and 3B at both ends of the insulating substrate (input signal pattern 3). Flexible piece 4,4
The flexible piece 4 (4
Both A) and the glass epoxy substrate 5 may be provided with a wiring pattern only on one surface. Therefore, there is no need for an expensive flexible board with double-sided wiring,
An inexpensive thermal head can be provided. Also, the insulating substrate 1
Since only the pressure contact at both ends of the pressure contact is required, the pressure contact work is easy and the reliability of the pressure contact is improved, and distortion due to tightening at the pressure contact can be reduced. Further, by connecting the both ends by soldering, it is possible to reduce the occurrence of warpage due to the difference in the coefficient of thermal expansion.

(F) Effects of the Invention According to the present invention, as described above, in the thermal head according to the first aspect, the first common electrode, the second common electrode, and the end portions (lead-out terminals) of the plurality of wiring patterns are insulated from each other. The following effects are obtained after the lead-out is arranged at the end of the second long side of the.

Not only does the number of pressure contact points of the signal wiring be small, but external signals can be input to each drive IC without using an expensive flexible board.

Since the lead-out terminals for the input signal are concentratedly arranged at the end of the second long side of the insulating substrate, warpage due to thermal expansion and connection failure with the outside are reduced.

The first and second common electrodes (common pattern and ground pattern) are provided around the insulating substrate, respectively, and a plurality of narrow wiring patterns (input signal wiring, etc.) inside the insulating substrate.
Since the wiring pattern is formed, the wiring pattern can be efficiently wired. That is, in the case where a configuration in which a plurality of narrow wiring patterns are formed around the substrate is adopted, for example, an insulating substrate is divided from a large substrate and a large number is taken,
When forming a pattern by screen printing, there is no fear of breaking the narrow wiring pattern. Moreover, since the common pattern and the ground pattern are wider than the other wiring patterns, the current capacity that can be supplied is large,
Even if all the dots are printed at the same time, the supply voltage does not drop, and it is possible to prevent a change in print quality due to print data.

The insulating substrate is formed by connecting to the outside at the end of the second long side facing the first long side of the insulating substrate on which the heating dot row is formed and separated from the first long side by a distance. Since there are no parts near the heating resistor that impede the connectivity between the heating resistor and the recording paper, the printing condition can be kept good, and the printing quality and printing efficiency are improved.

Since the second long side end of the insulating substrate is used as a connection space to the outside, the connection space can be sufficiently secured without increasing the width (width in the short side direction) of the insulation substrate, and the insulation substrate can be downsized. Becomes In other words, if the conventional configuration (see FIG. 6) is used in which the lead-out terminals for input signals are not collected at the end of the insulating substrate (see FIG. 6), the region inside the insulating substrate along the long side of the insulating substrate and the insulating substrate corresponding to the region A space consisting of the outside area is required, and as a result, the dimension of the insulating substrate in the short side direction becomes large,
The thermal head not only hinders the miniaturization of electronic equipment in which the thermal head is used, but also causes a problem that the number of picked-up insulating substrates decreases when a large insulating substrate is divided and taken in large numbers. The head does not have such a problem.

The thermal head according to the second aspect is for each drive.
Since the lead-out terminal of the input signal wiring pattern commonly connected to each input signal terminal of the IC and the glass epoxy board having the wiring pattern on one surface are pressure-contacted by the one-sided flexible piece, the second insulating board Long side ends (both ends)
Therefore, it is possible to provide a low-priced thermal head because the pressure welding work is simple and the pressure welding reliability can be improved.

[Brief description of drawings]

1 is a plan view showing an embodiment of a thermal head substrate according to the first claim, FIG. 2 is an exploded plan view showing an embodiment of a thermal head according to the second claim, and FIG. 3 is a second view. 4 is a side view showing the conventional thermal head, FIG. 4 is a side view showing the conventional thermal head, FIG. 5 is a plan view of the conventional thermal head, and FIG. It is a figure. 1: Insulation board, 2: Drive IC, 3: Input signal wiring pattern, 4: Single-sided flexible piece, 5: Single-sided epoxy board, 3A, 3
B: Lead-out terminal, 21: Input signal terminal.

Claims (2)

[Claims] 1. A heating dot row is provided along a first long side of an insulating substrate having a substantially rectangular shape in a plan view, and a plurality of drive ICs connected to the heating dot row on the insulating substrate are arranged in rows. In the thermal head configured as described above, on the insulating substrate, the end of the first long side passes between the tip of the heating dot row and the short side of the insulating substrate, and faces the first long side. A first common electrode formed up to the end of the second long side, a second common electrode formed along the second long side to the vicinity of the end, and a second common electrode. It is formed between a common electrode and a row of a plurality of drive ICs, and at the end of the second long side, the first common electrode and the second
Is formed along the short side direction between the common electrode tip portions of,
A thermal head formed by forming a plurality of wiring patterns having a width narrower than that of the first and second common electrodes. 2. A heat-generating dot row having a substantially rectangular shape in a plan view is provided along the first long side, and a plurality of drive ICs connected to the heat-generating dot row are arranged in a row. 1
Is formed at the end of the long side of the first heating side through the tip of the heating dot row and the short side of the insulating substrate to the end of the second long side facing the first long side. Common electrode of the second
Second strip formed along the long side of the to near the end
Common electrode, and this second common electrode for multiple drives
Is formed between the first common electrode and the second common electrode tip portion at the end of the second long side along the short side direction, and An insulating substrate formed with a plurality of wiring patterns having a width narrower than that of the first and second common electrodes, and a wiring pattern corresponding to a lead-out terminal formed at the end of the second long side of the insulating substrate. A thermal head comprising a glass epoxy substrate provided on one surface, and a one-sided flexible piece for connecting the lead-out terminal of the insulating substrate and the wiring pattern of the glass epoxy substrate by providing a wiring pattern corresponding to the lead-out terminal of the insulating substrate on one surface.