JPH0636037U - Wiring board and liquid crystal display device - Google Patents

Abstract

(57) [Summary] [Objective] The present invention aims to provide a wiring board capable of increasing the mounting density and significantly reducing the mounting area. According to the present invention, a resistor pattern made of an indium tin oxide (ITO) layer is provided instead of the chip resistor mounted on the wiring board. Further, in the second aspect of the present invention, on the glass substrate that constitutes the liquid crystal display panel,
A resistor pattern made of an indium tin oxide (ITO) layer is arranged.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a wiring board and a liquid crystal display device, and more particularly to mounting a resistor on the wiring board.

[0002]

[Prior art]

 In recent years, integration has been promoted in the field of semiconductor integrated circuits, and the number of pads for supplying input / output signals and power supply voltage has been increasing more and more, and operating speed has been accelerating.

In mounting a semiconductor integrated circuit integrated with high density as described above, the pad pitch can be reduced with an increase in the number of pads, and accordingly, a high density of a wiring pattern on a wiring board can be achieved. It is becoming increasingly popular.

For example, as shown in FIG. 7 and FIG. 8 of a liquid crystal display device using liquid crystal (FIG. 8 is an enlarged view of a main part of FIG. 7), on a printed wiring board 501 on which a wiring pattern is formed, The liquid crystal display unit 201 is sealed by a sealing member 205 and is connected via a flexible substrate 401 formed by forming a wiring pattern on the film. Here, the liquid crystal display unit 201 is driven by the liquid crystal controller driver 101 also mounted on the wiring board 501, and the liquid crystal controller driver 101 is provided with the chip resistors R _{1 to} R ₄ . These chip resistors R _{1 to} R ₄ are voltage dividing resistors used for supplying driving power sources V _{1 to} V ₅ that determine the brightness of the liquid crystal display.

[0005]

[Problems to be solved by the device]

 For this reason, the mounting area of the chip resistor has also been a big problem that prevents the device from being downsized. In addition, when connecting the chip resistors, it is necessary to use a solder reflow method or the like, and the handling is complicated. Furthermore, when it is necessary to change the resistance value for fine adjustment of the resistance value of the chip resistance, the chip resistance must be removed and replaced, which causes a problem of complicated handling.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wiring board capable of increasing the mounting density and significantly reducing the mounting area.

[0007]

[Means for Solving the Problems]

 Therefore, in the present invention, a resistor pattern made of an indium tin oxide (ITO) layer is provided on the substrate surface instead of the chip resistor mounted on the wiring substrate.

In the second aspect of the present invention, a resistor pattern made of an indium tin oxide (ITO) layer is arranged on a glass substrate which constitutes a liquid crystal display panel.

[0009]

[Action]

 According to the first configuration, the resistor pattern can be formed in the same step as the wiring pattern formation or by adding the resistor pattern formation step to the wiring pattern formation step. It becomes unnecessary to carry out, and handling becomes extremely easy.

Further, according to the second configuration, since the resistor pattern made of the indium tin oxide (ITO) layer is arranged on the wiring substrate of the liquid crystal display panel, the effect of the first configuration is obtained. In addition, trimming of the resistance value can be easily performed by reducing the pattern or the like, and high-accuracy luminance display without output variation can be performed.

Here, the resistance pattern may be on the glass plate of the liquid crystal display panel, or on the wiring board when the liquid crystal display panel is mounted on the wiring board. However, when it is formed on a glass plate, it is formed by using the same material in the same step as the formation of the electrode pattern of the liquid crystal, so that the number of steps can be reduced and the formation can be performed very easily.

Further, according to the present invention, the mounting area can be significantly reduced.

[0013]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a liquid crystal display device according to an embodiment of the present invention, FIG. 2 is an enlarged view of a main part of a liquid crystal display unit, and FIG. 3 is an explanatory diagram showing a connection relationship between the liquid crystal display unit 201 and a liquid crystal controller driver 101. 4 is a block diagram showing the connection relationship between the CPU 301, the liquid crystal display unit 201, the liquid crystal controller driver 101, and the voltage dividing resistor. In this liquid crystal display device, instead of mounting the chip resistors R _{1 to} R ₄ on the wiring board 501, a resistor pattern made of an indium tin oxide (ITO) layer is formed on the surface of the glass substrate 201 which constitutes the liquid crystal display panel. It is characterized by arranging r _{1 to} r ₄ . This resistor pattern has a sheet resistance of 400 Ω / mm ² and a width of 0. A pattern of 5 mm × length 10 mm is formed, and r ₁ = r ₂ = r ₃ = r ₄ = 2 kΩ is shown. Other parts are formed similarly to the conventional example. These resistors are voltage-dividing resistors used to supply the liquid crystal display driving power sources V _{1 to} V ₅ , and the resistance value can be easily controlled by adjusting the width and length.

That is, this liquid crystal display device includes a wiring board 501 on which a wiring pattern (not shown) is formed, an IC that constitutes the CPU 301 mounted on the wiring board 501, an IC that constitutes the liquid crystal controller driver 101, and a liquid crystal display. The display unit 201 is mounted, the data output terminals D _{0 to} D _{7 of} the CPU 301 are connected to the input terminals of the liquid crystal controller driver 101, and the common signal terminals COM _{1 to} COM ₈ and segment signals of the liquid crystal controller driver 101 are further connected. The terminals SEG _{1 to} SEG ₄₀ are connected to the liquid crystal display 201. Here, the liquid crystal display device 201 and the liquid crystal controller driver 101 are connected via a flexible substrate 401 having a wiring pattern formed on the surface of a polyimide film, and these connecting portions are each made of an anisotropic conductive film (see FIG. (Not shown). Here, a connection example in the case of 5 × 7 dots, 8 characters × 1 line, and 1/8 duty is shown.

Further, the liquid crystal display portion is made of TN (twisted nematic) type liquid crystal, and transparent electrodes 203 made of ITO pattern are opposed to each other on each surface as shown in the enlarged sectional view of one segment in FIG. The liquid crystal 210 is filled in the space formed by interposing the seal member 205 between the first and second glass plates 204 and 208 formed on the side where the liquid crystal is formed. Polarizing plates 202 and 207 are attached to the outsides of the first and second glass plates, respectively, and a reflecting plate 206 is provided outside the polarizing plate 207 on the back side.

Next, the operation of this liquid crystal display device will be described.

First, when a data signal is input from the data output terminals D _{0 to} D _{7 of the} CPU 301 to the liquid crystal controller driver 101, the common signal terminals COM _{1 to} COM ₈ and the common signal terminals COM _{1 to} COM _{8 of the} liquid crystal controller driver 101 and Voltages are applied from the segment signal terminals SEG _{1 to} SEG ₄₀ to the upper electrode 203 and the lower electrode 203 of the liquid crystal display 201, respectively. Here, a reflector is installed on the back surface of the lower electrode 203, and the upper electrode 203 side is the display surface side.

Then, according to the timing, the voltage application of 5 steps of the magnitude set to r ₁ to r ₄ is performed, and the display is performed.

In the TN type liquid crystal display, when no voltage is applied, the liquid crystal molecules are arranged by twisting 90 degrees between the upper and lower glass plates as shown in FIG. It is twisted. The light passing therethrough is twisted by 90 degrees to pass along the liquid crystal molecules, and then passes through the polarizing plates 202 and 207 to transmit the light as a whole, which is in a transparent and non-display state.

However, when a voltage is applied, the twist of the liquid crystal molecules is released, the twist is arranged along the electric field, and the light goes straight without being twisted. Since the polarizing plates 202 and 207 are twisted by 90 degrees with respect to each other, when light goes straight, they cannot pass through the polarizing plate and cannot pass through the light as a whole, resulting in a black display state.

As described above, according to the liquid crystal display device of the present invention, it is not necessary to mount the chip resistor, and the handling becomes extremely easy. Further, on the glass substrate of the liquid crystal display panel, the trimming of the resistance value can be easily performed by reducing the pattern or the like, and the highly accurate luminance display without the output variation can be performed.

In the above embodiment, the voltage dividing resistor for supplying the power supply voltage for driving the liquid crystal display is formed by the ITO pattern on the glass substrate of the liquid crystal display, but it may be arranged on the wiring substrate. Alternatively, other resistors in the electronic circuit may be formed by the ITO pattern.

Furthermore, although the liquid crystal display device has been described in the above embodiment, the present invention is not limited to this, and can be applied to other elements such as a thin film EL element and an image sensor.

[0025]

[Effect of device]

 As described above, according to the present invention, the mounting area can be reduced, the weight can be reduced, the manufacturing is easy, and the resistance value can be adjusted very easily.

[Brief description of drawings]

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

FIG. 2 is an enlarged view of a main part of the device.

FIG. 3 is an enlarged explanatory view of the device.

FIG. 4 is a block diagram of the device.

FIG. 5 is an explanatory diagram of a liquid crystal display unit of the device.

FIG. 6 is an explanatory cross-sectional view of a main part of a liquid crystal display unit of the device.

FIG. 7 is a diagram showing a conventional liquid crystal display device.

FIG. 8 is an enlarged view of a main part of the device.

[Explanation of symbols]

 101 liquid crystal controller driver 201 liquid crystal display 202 deflection plate 203 electrode 204 first glass plate 205 seal member 206 reflection plate 207 deflection plate 208 second glass plate 210 liquid crystal 301 CPU 401 flexible substrate 501 wiring board

Claims (2)

[Scope of utility model registration request] 1. A wiring board, wherein a resistor pattern made of an indium tin oxide (ITO) layer is provided on a surface of a substrate having an insulated surface. 2. A liquid crystal display device characterized in that a resistor pattern made of an indium tin oxide (ITO) layer is provided on the surface of a glass substrate constituting a liquid crystal display panel.