JPH11326937A - Liquid crystal display device and method of assembling the same - Google Patents

Abstract

(57) [Problem] To provide a small liquid crystal display device used for a mobile phone or the like, which is provided with circuit components for boosting, adjusting a voltage, and the like, and at the same time reduces costs. SOLUTION: In addition to a liquid crystal panel 10 and a tape carrier package 14 on which a driver for driving the liquid crystal panel 10 is mounted, a flexible printed wiring board 19 connected to the tape carrier package 14 is provided. Circuit components constituting a peripheral circuit of the driver are mounted on the flexible printed wiring board 19. LCD panel 1
After connecting the tape carrier package 14 to the tape carrier package 14 and measuring the characteristics of the liquid crystal panel and the driver, the flexible printed wiring board 19 on which the circuit components having the circuit constants selected according to the measurement results are mounted. Connect to

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small and inexpensive liquid crystal display device used for a portable telephone or the like.

[0002]

2. Description of the Related Art In a liquid crystal display device used for a small portable device such as a cellular phone, there is a high demand for displaying kanji characters which are easier to read than kana characters. One of the problems in displaying characters with a large number of constituent dots, such as the display of kanji characters, is that the duty ratio in dynamic lighting is reduced, so that it is necessary to increase the drive voltage accordingly. Specifically, 1/26 to 1 /
33, and a duty ratio of 1/48 to 1/65 is required. In order to increase the driving voltage, circuit components such as a boosting capacitor, a temperature compensating thermistor, a resistor, and a semi-fixed resistor, which are not necessary in the past, are required.

FIG. 3 shows a conventional structure of such a liquid crystal display device. In FIG. 3, reference numeral 10 denotes a liquid crystal panel, 11 denotes a polarizing plate, 12 denotes a display unit, and 13 denotes a tape carrier package (hereinafter, referred to as TCP) on which a driver (drive circuit) of the liquid crystal panel is mounted. The TCP 13 has a bending slit 14, a driver mounting section 15, a circuit component mounting section 16, an output terminal connection section 17, and an input connector connection section 18.

The common and segment transparent electrodes provided on the display section 12 of the liquid crystal panel 10 are connected to the output terminal connection section 1.
7 is connected to a driver mounted on the TCP 13. The electrical connection between the liquid crystal panel 10 and the TCP 13 at the output terminal connection portion 17 is usually made using an anisotropic conductive resin.

A circuit component mounting portion 16 provided near the driver mounting portion 15 of the TCP 13 includes a capacitor for boosting a voltage supplied to the driver, a thermistor for temperature compensation, a resistor for voltage setting, A semi-fixed resistor and the like for correcting a step-up variation of a liquid crystal panel and a driver are mounted.

[0006]

As described above, when not only the driver but also peripheral circuit components are mounted on the TCP 13, the number of connection terminals between the device body and the liquid crystal display device is reduced (10 to 20). This has the advantage that the size of the connector can be reduced. However, this method has a disadvantage that the size of the TCP 13 becomes large due to the circuit component mounting section 16 and the cost becomes high. For this reason, it is not suitable for applications requiring strict cost reduction, such as mobile phones.

On the other hand, there is a method of mounting peripheral circuit parts on a printed circuit board of the device main body. In this case, however, the number of connection terminals between the device main body and the liquid crystal display device is increased (about 30 to 45), and a connection connector is provided. However, there is a problem in that the mounting space and the weight of the entire device increase. In addition, when adjusting the variation of the drive voltage characteristic or the boosted value of the drive driver with respect to the temperature change of the liquid crystal panel by changing the circuit constant of the peripheral circuit, it is difficult to adjust the circuit component by mounting the circuit components on the device body. In particular, when the manufacturer or the manufacturing factory of the liquid crystal display device and the device main body are different, it is difficult to start mass production in a short period of time.

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention is provided with a liquid crystal display device capable of suppressing a rise in cost while being provided with circuit components for boosting, voltage adjustment and the like, and a method of assembling the same. The purpose is to provide.

[0009]

A liquid crystal display device according to the present invention is a liquid crystal display device comprising a liquid crystal panel and a tape carrier package on which a driver for driving the liquid crystal panel is mounted, the liquid crystal display device being connected to the tape carrier package. And a circuit component constituting a peripheral circuit of the driver is mounted on the flexible printed circuit board. According to this configuration, the area of the expensive tape carrier package can be reduced and an inexpensive liquid crystal display device can be obtained.

Further, in the method for assembling a liquid crystal display device according to the present invention, the liquid crystal panel is connected to a tape carrier package on which a driver for driving the liquid crystal panel is mounted, and the characteristics of the liquid crystal panel and the driver are measured. A flexible printed wiring board on which a circuit component having a circuit constant selected according to a measurement result is connected to a tape carrier package. According to such an assembling method, for example, it is easy to optimize a boosting circuit of a driving voltage provided as a peripheral circuit in accordance with a characteristic variation of a liquid crystal panel and a driver.

The electrical connection between the tape carrier package and the flexible printed wiring board can be made by applying heat and pressure to the respective connecting portions via an anisotropic conductive resin. As a more preferred method, the respective connection portions of the tape carrier package and the flexible printed wiring board are tin-plated, and the two connection portions can be electrically connected to each other by applying heat and pressure while in contact with each other. According to this method, an anisotropic conductive resin becomes unnecessary and the number of work steps is reduced, so that a more inexpensive liquid crystal display device can be obtained.

[0012]

FIG. 1 shows a first embodiment of the present invention. In FIG. 1, reference numeral 10 denotes a liquid crystal panel, 11 denotes a polarizing plate, 12 denotes a display unit, 13 denotes a tape carrier package (TCP), and 19 denotes a flexible printed wiring board (FP).
C). The TCP 13 has a bending slit 14,
It has a driver mounting section 15 and an output terminal connection section 17. The FPC 19 has a circuit component mounting section 16, an input connector connection section 18, and an input terminal connection section 20.

The electrical connection between the TCP 13 and the FPC 19 at the input terminal connection 20 is the same as the electrical connection between the liquid crystal panel 10 and the TCP 13 at the output terminal connection 17.
This is performed by thermocompression bonding using an anisotropic conductive resin.

According to the above-described configuration, the circuit components for boosting, voltage adjustment, etc. are connected to the FPC connected to the TCP 13.
19, these circuit components are expensive TCP
Since the size of the TCP 13 can be significantly reduced as compared with the case where the liquid crystal display device is mounted on a liquid crystal display device, an inexpensive liquid crystal display device can be obtained. In addition, since these circuit components are mounted on a liquid crystal display device in which the liquid crystal panel 10, the TCP 13, and the FPC 19 are integrated, compared with a case where these circuit components are mounted on a device body side where the liquid crystal display device is used. ,
The number of connection terminals between the main unit and the LCD is reduced,
Adjustments such as changing the constants of the circuit components can be easily performed separately from the main body. Furthermore, the LCD driver is TCP
In addition, by mounting the peripheral circuit components separately on the FPC, it is possible to prevent a decrease in the strength of the copper foil of the TCP 13 and a deterioration such as pattern deformation due to heat at the time of mounting.
It also contributes to improved reliability.

Further, it is also possible to apply tin plating to each connection portion between the TCP 13 and the FPC 19 and to make an electrical connection by directly applying heat and pressure without using an anisotropic conductive resin.
According to this method, materials and man-hours are reduced, and a more inexpensive liquid crystal display device can be obtained.

Next, a second embodiment of the present invention is shown in FIG. This embodiment differs from the first embodiment shown in FIG. 1 in the connection between the TCP 13 and the FPC 19.
In FIG. 1, the liquid crystal panel 10, TCP 13, and FPC 19
Are placed on the lower part of the TCP 13 so that
Although the input terminal connection unit 20 of the PC 19 is connected, in FIG. 2, the liquid crystal panel 10, the TCP 13, and the FPC 19 are connected.
Are placed on the right side of the TCP 13 so that
The input terminal connection unit 20 of the PC 19 is connected. Other configurations are the same as those of the first embodiment shown in FIG. Note that a configuration in which the input terminal connection unit 20 of the FPC 19 is connected to the left side of the TCP 13 is also possible.

As described above, when the peripheral circuit is mounted on the TCP 13 and another FPC 19, the liquid crystal panel 1 depends on where the connection between the TCP 13 and the FPC 19 is arranged.
There is a degree of freedom in the shape and the like of the liquid crystal display device in which the 0, TCP 13 and FPC 19 are integrated. Therefore, there is an advantage that the degree of freedom in the structural design for incorporating the liquid crystal display device into the device is increased.

[0018]

As described above, in the liquid crystal display device of the present invention, after the circuit components are mounted on the flexible printed wiring board, the flexible printed wiring board is connected to the tape carrier package on which the driver is mounted, so that an expensive tape is used. The cost can be reduced by reducing the area of the carrier package, and various advantages as described above can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a conventional liquid crystal display device.

[Explanation of symbols]

 Reference Signs List 10 liquid crystal panel 11 polarizing plate 12 display unit 13 TCP 14 bending slit unit 15 drive driver mounting unit 16 circuit component mounting unit 17 output terminal connection unit 18 input connector connection unit 19 FPC 20 input terminal connection unit

Claims (5)

[Claims] 1. A liquid crystal display device comprising: a liquid crystal panel; and a tape carrier package on which a driver for driving the liquid crystal panel is mounted, further comprising: a flexible printed wiring board connected to the tape carrier package. A liquid crystal display device, wherein circuit components constituting a peripheral circuit of the driver are mounted on the flexible printed wiring board. 2. The liquid crystal display device according to claim 1, wherein said circuit components include a capacitor, a resistor, a thermistor, and a semi-fixed resistor. 3. The liquid crystal panel is connected to a tape carrier package on which a driver for driving the liquid crystal panel is mounted, and after measuring characteristics of the liquid crystal panel and the driver, a circuit selected according to the measurement result. A method for assembling a liquid crystal display device, comprising: connecting a flexible printed wiring board on which constant circuit components are mounted to the tape carrier package. 4. An electrical connection between the tape carrier package and the flexible printed wiring board by thermally pressing a connection portion between the tape carrier package and the flexible printed wiring board via an anisotropic conductive resin. 4. The method for assembling a liquid crystal display device according to claim 3, wherein the method is performed. 5. A connection part between the tape carrier package and the flexible printed wiring board is tin-plated, and the tape carrier package and the flexible printed wiring board are heated by applying heat while both connection parts are in contact with each other. 4. The method for assembling a liquid crystal display device according to claim 3, wherein an electrical connection is made with a printed wiring board.