JPH054284Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Technical field This invention relates to an integrated circuit device for a drive circuit used for driving thermal heads, LEDs, etc.

(b) Conventional technology and its drawbacks Driver IC for driving thermal heads, etc.
It typically incorporates a shift register with several dozen stage outputs, and has a serial input terminal, a serial output terminal, and a parallel output terminal. When using such a driver IC to drive a thermal head with a very large number of dots in the row direction,
Generally, in order to reduce the load on the power supply section, cascade-connected driver ICs are divided into multiple blocks, and the drive timing of each block is staggered. Therefore, it is necessary to provide input/output data terminals for each block on the board.

FIG. 3A is a pin layout diagram of the driver IC, and FIG. 3B is a schematic configuration diagram of the driver IC.
This driver IC is a 32-bit IC with a built-in shift register that has 32 stages in total.
As shown, the serial input terminal SiT is arranged at one end of one terminal mounting side of the chip, and the serial output terminal SoT is arranged at one end of the other terminal mounting side. In addition, parallel output terminal Po
A total of 32 terminals from 1 to Po32 are Po1 to Po16.
are arranged in order following the upper and lower serial input terminals SiT on one terminal mounting side of the chip, and Po17 to
Po32 is arranged in order following the serial output terminal SoT on the other terminal mounting side. Further, among the above output terminals, a clock terminal, a GND terminal, etc. are arranged following Po16 and Po17. I C
In some cases, these clock terminals and GND terminals are located in the center of the chip. FIG. 3B shows the connection state between the shift register SR and each of the above terminals. D1 to D3 of shift register SR
2 indicates a cell. A serial input terminal SiT is connected to the input terminal of the shift register SR, that is, the input terminal of the cell D1, and a serial output terminal SoT is connected to the output terminal of the shift register SR, that is, the output terminal of the cell D32. Also, the output terminal of each cell is Po1, which is the parallel output terminal of the chip.
~Connected to Po32. FIG. 4 shows the state of the wiring pattern on the board when a total of six driver ICs having the above configuration are used to construct a driving circuit for a thermal head. The number of blocks is 2
Each block B1 and B2 is composed of cascade-connected IC1 to IC3 and IC4 to IC6, respectively. The input signal of block B1 is from the input data terminal IN1 on the board to the serial input terminal SiT of IC1.
is supplied to Also, the output data of block B1 is
It is supplied from the serial output terminal SoT of IC3 to the output data terminal OUT1 arranged on the board.
The connection between IC1 and IC3 is the serial output terminal of IC1.
By connecting SoT and the serial input terminal SiT of IC2, and further connecting the serial output terminal SoT of IC2 and the serial input terminal SiT of IC3, a cascade connection state is established. Block B2 is also similar to block B1.

On the other hand, there are generally two methods for forming a wiring pattern on a substrate. One method is to form wiring patterns from each parallel output terminal in a concentrated manner at the bottom of the IC. However, with this method, it is difficult to pattern the GND electrode, which must have a relatively large current capacity. Another method is to pass a GND electrode under the IC chip and form wiring patterns from each parallel output terminal between adjacent ICs in a concentrated manner. With this method, it is easy to pattern the GND electrode, and it is also easy to increase the electrode area, so it is easy to pattern the GND electrode and increase the electrode area.
IC chips can be used. The drive circuit shown in FIG. 4 uses the latter method.
In the figure, GND indicates a GND electrode, and L indicates a pattern of wiring lines extending from each parallel output terminal Po1 to Po32 to a thermal head portion (not shown).

However, if a wiring pattern is formed between each IC as shown in Figure 4, the input/output terminals between the ICs can be easily connected with a short jumper line because the interval between them is short. If the wiring pattern is such that it extends along the serial input/output terminal, the wiring pattern between the input data terminal IN1 of the board and the serial input terminal SiT of IC1, and between the output data terminal OUT1 of the board and the serial output terminal SoT of IC3 is The connection must be made using a long jumper wire or the like so as not to intersect the wiring pattern from each parallel output terminal. Generally, a ceramic substrate with good heat resistance is used as the drive circuit substrate on which the ICs 1 to 6 are mounted, so it is not possible to form wiring lines using the back surface of the substrate by using through holes or the like.
Therefore, when using a board with multiple wiring patterns formed between ICs, depending on the direction in which the wiring patterns extend, it may be difficult to use the conventional driver.
As long as an IC is used, the input/output data terminals of the board and the IC
The drawback is that a long jumper wire or the like must be used to connect the serial input/output terminals of the device, or a complicated wiring pattern must be formed to eliminate such a jumper wire connection.

(c) Purpose of the invention The purpose of this invention is to eliminate the use of long jumper wires by providing a driver IC with multiple serial input terminals and serial output terminals, and by devising the arrangement of these input and output terminals. An object of the present invention is to provide an integrated circuit device for a drive circuit in which a wiring pattern can be easily formed even when a higher density wiring pattern is formed.

(d) Structure of the invention This invention includes a built-in shift register, and has a serial input terminal, a serial output terminal, and a parallel output terminal of the shift register.
In a plurality of drive circuit integrated circuit devices arranged on a drive circuit board, parallel output terminals are provided on first and second terminal mounting sides facing each other in the arrangement direction on the drive circuit board; Serial input terminals are provided near both ends of the second terminal mounting side, and serial output terminals are provided near both ends of the second terminal mounting side.

With the above configuration, by using one of the two serial input terminals and two serial output terminals near both ends, the jumper wire (bonding wire) connected to that input/output terminal can be connected to each terminal. This allows patterning to be easily performed without crossing the wiring lines extending from the parallel output terminal.

(e) Embodiment FIGS. 1A and 1B are a layout diagram and a schematic configuration diagram of a driver IC that is an embodiment of this invention. The difference in configuration from the conventional driver IC shown in FIG. 3 is that the driver IC of this embodiment has serial input terminals SiT1 and SiT2 at both ends of one terminal mounting side of the chip, and Serial output terminals SoT1 and SoT2 are provided at both ends of the other terminal mounting side, respectively. As shown in Figure B, these serial input terminals SiT1, SiT2 and serial output terminal
SoT1 and SoT2 are each connected internally and configured so that either input/output terminal can be used.

FIG. 2 is a diagram showing the state of the wiring pattern when a driving circuit is constructed on a board using this driver IC. To connect the input data terminal IN1 on the board of block B1 and the serial input terminal of IC1, the serial input terminal SiT2 on the lower side facing the drawing of IC1 is used. To connect the data output terminal OUT1 on the board of block B1 and the serial output terminal of IC3, terminal SoT2 on the lower side as viewed from the drawing of IC3 is used. Also block B
The serial input terminal SiT2 of IC4 is used to connect the input data terminal IN2 on the board 2 and the serial input terminal of IC4, and the output data terminal on the board
To connect OUT2 and the serial output terminal of IC6,
The serial output terminal on the lower side facing the drawing of IC6
SoT2 is used. Wiring lines lin1, lout1, lin2, and lout2 connecting these are each formed as a wiring pattern on the substrate. As shown in the figure, since the thermal head section driven by each IC is located at the upper part of the drawing, wiring lines L extend upward from the parallel output terminals Po1 to Po32 of each IC. Therefore, the wiring line connecting the input/output data terminal on the board and the serial input terminal of the driver IC does not intersect with the wiring line L extending upward from each parallel output terminal. Therefore, the wiring pattern is simplified,
Moreover, the length of the wiring line can also be minimized. Of course, there is no need to use long jumper wires.

In addition, in the example shown in Fig. 2, between IC1 and IC2,
Between IC2 and IC3, between IC4 and IC5, and between IC5 and IC6
In order to connect the serial signals between them, the serial input terminal and serial output terminal on the upper side were used as shown in the figure, but as shown in Fig. The serial input terminal and serial output terminal on the lower side of the figure may be used to connect serial signals between adjacent ICs by applying the integrated circuit device. In this case, between IC1 and IC2, between IC2 and IC3,
Although the lengths of the jumper wires between IC4 and IC5 and between IC5 and IC6 are the same as in the case of FIG. 2, it is possible to completely eliminate the possibility of short circuits in the wiring lines on the board due to slack in the jumper wires.

(f) Effect of the invention As mentioned above, according to this invention,
By simply providing serial input terminals at both ends of one terminal mounting side of the IC chip and serial output terminals at both ends of the other terminal mounting side, wiring lines extending from the parallel output terminal and serial input/output terminals can be connected. Intersection with wiring lines extending from the wiring can be easily prevented without complicating the wiring pattern or using long jumper wires. For this reason, especially when the wiring pattern becomes dense, when using a driver IC with a very large number of parallel output terminals (high number of bits), and when connecting ICs in cascade, the number of blocks increases. This has the effect of making wiring pattern formation relatively simple.

[Brief explanation of the drawing]

Figures 1A and B are pin layout diagrams and internal schematic diagrams of a driver IC (integrated circuit device for driving circuits) that is an embodiment of this invention; Figure 2 is for the same driver.
FIG. 3 is a diagram showing the state of a wiring pattern when a drive circuit is configured on a substrate using an IC. Also the third
Figures A and B are pin layout diagrams of conventional driver ICs.
Schematic internal configuration diagram, Figure 4 is the driver IC
FIG. 3 is a diagram showing the state of a wiring pattern when a drive circuit is constructed on a substrate using the following. FIG. 5 is a diagram showing the state of another wiring pattern when a driving circuit is constructed on a board using a driver IC according to an embodiment of this invention. SiT1, SiT2...Serial input terminal, SoT
1, SoT2...Serial output terminal, Po1~Po3
2...Parallel output terminal.

Claims (1)

[Claims for Utility Model Registration] A driver circuit integrated circuit device that includes a built-in shift register and has a serial input terminal, a serial output terminal, and a parallel output terminal of the shift register, and is arranged in plurality on a drive circuit substrate. In this case, a parallel output terminal is provided on each of the first and second terminal mounting sides facing each other in the direction of arrangement on the drive circuit board, serial input terminals are provided near both ends of the first terminal mounting side, and a serial input terminal is provided near both ends of the first terminal mounting side. An integrated circuit device for a drive circuit, characterized in that serial output terminals are provided near both ends of the terminal mounting side.