JPH1124096A - Liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the array order of output leads of an LSI chip for liquid crystal driving correspond to the array order of transparent electrodes on the side of a liquid crystal display element. SOLUTION: The liquid crystal display element has 1st and 2nd transparent electrodes 1 and 2 arranged opposite each other across a sealant 3, liquid crystal is charged between the transparent electrodes, and a terminal part 5 which has draw-around electrodes 1b led around from the transparent electrode of the 1st transparent substrate 1 below the sealant 3 is provided successively to the 1st transparent substrate 1; and a wiring cross means 20 which connects a specific draw-around electrode 1b to an arbitrary transparent electrode on the side of the 1st transparent substrate 1 by jumping other draw-around electrodes is provided on the join surface between the seal material 3 and 2nd transparent substrate 2 and in the sealant 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a COG type, TCP having a terminal portion on one electrode substrate and inputting a display signal from the terminal portion to a transparent electrode. The present invention relates to a liquid crystal display device of the type.

[0002]

2. Description of the Related Art COG stands for Chip On Glass.
The COG-type liquid crystal display device has a liquid crystal driving LSI chip directly mounted on a terminal portion thereof. FIG.
(A) shows one transparent substrate 1 of the COG type liquid crystal display element, and (b) shows the other transparent substrate 2 as a plane.

According to this, a transparent electrode 1a for display (segment electrode in this example) 1a and a routing electrode 1b for transmitting a drive signal to the transparent electrode 1a are formed on one transparent substrate 1. A transparent electrode 2a for display corresponding to the transparent electrode 1a of the substrate 1;
A routing electrode 2b for transmitting a drive signal to the transparent electrode 2a is formed.

[0004] FIG. 4 is a plan view showing a state where the transparent substrates 1 and 2 are opposed to each other, bonded with a sealing material 3 made of, for example, an epoxy resin, and then a liquid crystal is sealed in the display cell. FIG. 5 shows a cross section taken along the line BB. In FIG. 5, reference numerals 4a and 4b denote each transparent electrode 1.
a, an alignment film made of, for example, a polyimide-based organic polymer.

[0005] One transparent substrate 1 is attached to the other electrode substrate 2.
The terminal portion 5 is connected to the terminal portion 5 so as to protrude. The terminal portion 5 is provided with a routing electrode 6a that is electrically connected to the routing electrode 2b of the transparent substrate 2 via a transfer 6 formed in the sealing material 3.

The lead electrodes 1b,
A liquid crystal driving LSI chip 7 is directly mounted on the semiconductor chip 6a via an anisotropic conductive film.
The input printed board 8 for the I chip 7 is connected. Note that a silicone resin 9 for anticorrosion is applied on the routing electrodes 1b and 6a.

As a result, the driving signal output from the liquid crystal driving LSI chip 7 is transmitted to the transparent electrode 1a on the transparent substrate 1 side.
Is transmitted through the routing electrode 1b to the transparent electrode 2a on the transparent substrate 2 side.
a, transfer 6 and routing electrode 2b.

Next, referring to FIG. 6, TCP (Ta
A general configuration of a (pe Carrier Package) type liquid crystal display device will be described. Although the basic configuration of the liquid crystal display element itself is the same as that of the COG type, this TCP
In the liquid crystal display device, a liquid crystal driving LSI chip 7
Is mounted on the side of a TCP board (often a flexible printed board) 10 as a carrier tape, and its TC
The output terminal of the P substrate 10 has a lead-out electrode 1 of the terminal 5 via an anisotropic conductive film 11 having conductivity only in the thickness direction.
b, 6a.

[0009]

However, when the display patterns of the transparent electrodes 1a and 2a become complicated, the arrangement of the output terminals of the LSI chip 7 for driving liquid crystal leads to the arrangement of the leading electrodes 1b and There is a case where it is not possible to correspond to the arrangement order of 6a.

A conventional measure against this problem is shown in FIG.
A description will be given using a P-type liquid crystal display element as an example. In this example, the arrangement order of the routing electrodes 1b on the transparent substrate 1 side is changed, and the routing electrodes 6a on the transparent substrate 2 side are not shown for convenience.

In this conventional example, a liquid crystal driving LSI
In connecting the TCP substrate 10 on which the chip 7 is mounted to the terminal portion 5 on the liquid crystal display element side, a double-sided (multi-layer) flexible printed board 12 is used. That is, the flexible printed circuit board 12 includes a liquid crystal driving LSI
The connection wires 12a are formed by rearranging the output leads 7a of the chip 7 in a necessary order and connecting to the leading electrodes 1b of the terminal portions 5.

In the illustrated example, thirteen connection wirings 12 are provided.
Among the wirings a-1 to 12a-13, the connection wirings 12a-3 to 12a-13 from the third right to the left end are formed on the front surface side of the flexible printed circuit board 12. On the other hand, two connection wirings 12a on the right are formed. Reference numerals -1 and 12a-2 denote two right output leads 7a-1 and 7a-2 on the rear surface side of the flexible printed circuit board 12 and two left lead wires 1b-1.
2, 1b-13, the connection wiring 12 on the front side
a-3 to 12a-13 so as to cross each other.

As described above, in the TCP type liquid crystal display element, the arrangement order of the output terminals of the liquid crystal driving LSI chip 7 is made to correspond to the arrangement order of the lead-out electrodes 1b on the terminal portion 5 side. Requires a flexible printed circuit board 12, which inevitably increases the cost. Further, the terminal portion 5 and the TCP substrate 10
Flexible printed circuit board 12 for cross wiring between
Since a space for interposing the liquid crystal is also required, it is difficult to reduce the size of the liquid crystal display element.

Moreover, the flexible printed circuit board 1
2 cannot be applied to a COG-type liquid crystal display element in which the liquid crystal driving LSI chip 7 is directly mounted on the terminal portion 5. This is a great design constraint, especially for COG-type liquid crystal display devices.

The above problem can be solved by changing the arrangement order of the output leads 7a of the liquid crystal driving LSI chip 7 in accordance with the arrangement order of the lead electrodes 1b on the liquid crystal display element side. Therefore, the price of the LSI chip 7 for driving a liquid crystal becomes high and cannot be said to be a practical solution.

The present invention has been made to solve such a conventional problem, and has as its object not only the necessity of a flexible printed circuit board for cross wiring but also the output lead of an LSI chip for driving a liquid crystal. It is therefore an object of the present invention to provide a liquid crystal display element in which the arrangement order of output leads of the liquid crystal driving LSI chip can be made to correspond to the arrangement order of the transparent electrodes on the liquid crystal display element side without the necessity of rearranging the elements.

[0017]

In order to achieve the above object, the present invention is directed to a first and a second transparent substrates, each having a transparent electrode group formed on one surface thereof, sandwiching a sealing material. The transparent electrode groups are arranged to face each other, a liquid crystal is sealed between the transparent electrode groups, and the first transparent substrate has a plurality of wirings drawn out from the transparent electrode groups through the sealing material. In a liquid crystal display element in which terminal portions having electrodes are provided in series, the specific routing electrode jumps from another routing electrode to the bonding surface between the sealing material and the second transparent substrate and within the sealing material. And a wiring cross means for connecting to an arbitrary transparent electrode on the first transparent substrate side.

According to this configuration, the arrangement order of the lead-out wirings is changed by the wiring crossing means in the sealing material portion. The present invention can be applied to both a COG type liquid crystal display element and a TCP type liquid crystal display element. In particular, a COG type liquid crystal display element greatly improves design flexibility.
Further, the TCP type liquid crystal display element does not require a flexible printed board for cross wiring.

In the present invention, the wiring cross means includes:
It is composed of two transfers for the cross wiring penetrating through the inside of the sealing material, and a connection wiring portion formed between the two transfers for the cross wiring on the joint surface between the sealing material and the second transparent substrate. Preferably.

In this case, for the transfer for the cross wiring, a conductive paste or an epoxy resin kneaded with conductive particles is used in the same manner as in a normal transfer.
In the sealing material forming step, it can be formed by screen printing or the like. For example, the following two methods are available.

As a first method, a mask is applied to a portion where the cross-wiring transfer is to be provided and a seal material is screen-printed, and then a cross-wiring transfer is screen-printed to the portion where the mask is applied. The second method is the reverse of the above. First, a cross-wiring transfer is screen-printed at a predetermined position, and thereafter, a seal material is screen-printed except for the cross-wiring transfer portion.

In the connection wiring portion, in the transparent electrode forming step, the transparent electrode material (Indium Tin O 2) is used.
xide) can be formed simultaneously with the transparent electrode group.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment will be described with reference to FIGS. 1 and 2 in order to better understand the technical concept of the present invention. In this embodiment, parts that are the same as or are deemed to be the same as those of the conventional example described above are given the same reference numerals.

This embodiment relates to a COG type liquid crystal display device, and FIG. 1 is a plan view thereof, and FIG.
It is a line expanded sectional view. One first transparent substrate 1 and the other second transparent substrate 2 are bonded together with a sealant 3 interposed therebetween, and a terminal portion 5 of the first transparent substrate 1 is provided with a transparent electrode 1a.
A plurality of routing electrodes 1b are formed so as to be drawn out of the sealing material 3 from below.

In the terminal portion 5 of the first transparent substrate 1, a routing electrode 6a on the second transparent substrate 2 side is formed.
In this embodiment, the routing electrode 6a is connected to the routing electrode 2b on the side of the second transparent substrate 2 via a normal transfer 6 as in the conventional example.

The liquid crystal driving LSI chip 7 is mounted on the routing electrodes 1b and 6a so that their output leads coincide with each other. According to this embodiment, a portion of the sealing material 3 where the routing electrode 1b extends is provided. Is provided with a wiring crossing means 20 for changing the arrangement order of the routing electrodes 1b with respect to the transparent electrodes 1a.

As shown in FIG. 2, the wiring crossing means 20 joins two transfer wires 21 and 22 for cross wiring penetrating through the inside of the sealing material 3 and a joint between the sealing material 3 and the second transparent substrate 2. And a connection wiring portion 23 formed on the surface.

One cross-wiring transfer 21 is arranged on a specific routing electrode 1b whose arrangement order is to be changed, in this example, the rightmost routing electrode 1b-1, and the other cross-wiring transfer 22 is arranged on the routing electrode 1b-. 1 is disposed on the transparent electrode 1a-1 which is a connection destination. The connection wiring section 23 is provided with the cross-wiring transfer 21, 22.
It is provided between them.

According to this, the liquid crystal driving LSI chip 7
The display signal sent to the routing electrode 1 b-1 from one of the devices passes through one cross wiring transfer 21, the connection wiring part 23, and the other cross wiring transfer 22,
That is, the lead wire 1b on the way is jumped and given to the transparent electrode 1a-1 as the connection destination.

In this embodiment, the second leading electrode 1b-2 from the right is also connected to the transparent electrode 1a-2 adjacent to the transparent electrode 1a-1 via the wiring cross means 20.
The other leading electrode 1b is connected to the corresponding transparent electrode 1a under the sealing material 3.

The wiring cross means 20 is provided for each routing electrode 1b which needs to be rearranged. Therefore, when a plurality of wiring cross means are required, it is preferable to increase the width of the sealing material 3 so as to fit within the width. However, if the width of the sealing material 3 cannot be widened by design, Alternatively, the wiring crossing means 20 may be provided on the outer portion 5a of the seal member 3, which is the outer portion (the side opposite to the liquid crystal display portion).

However, when the outer portion 5a of the seal portion is used, the connection wiring portion 2 crossing the routing electrode 1b in the middle is used.
Since the distance between the wiring 3 and the wiring 3 is as small as 10 μm or less, and both wirings may be electrically connected to each other due to moisture and dirt, it is necessary to provide a protective layer such as a silicone resin on the outside 5a of the sealing portion. Although the above embodiment is directed to a COG type liquid crystal display device, the present invention can be similarly applied to a TCP type liquid crystal display device.

[0033]

As described above, according to the present invention,
By providing a wiring crossing means for changing the arrangement order of the routing electrodes with respect to the transparent electrodes in the sealing material portion, the degree of freedom in designing the COG type liquid crystal display element is greatly improved. In addition, the TCP type liquid crystal display element has an effect that a flexible printed board for cross wiring is not required.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a COG type liquid crystal display device to which the present invention is applied.

FIG. 2 is an enlarged sectional view taken along line AA of FIG. 1;

FIG. 3 is a schematic plan view separately showing first and second transparent substrates constituting a COG type liquid crystal display device as a first conventional example.

FIG. 4 is a schematic plan view of a first conventional COG-type liquid crystal display device obtained by bonding the first and second transparent substrates.

FIG. 5 is an enlarged sectional view taken along line BB of FIG. 4;

FIG. 6 is an enlarged cross-sectional view similar to FIG. 5, with a part of a TCP-type liquid crystal display element as a second conventional example in cross section.

FIG. 7 is a schematic plan view for explaining a method of changing the arrangement order of leading electrodes in the second conventional example.

[Explanation of symbols]

 1, 2 Transparent substrate 1a, 2a Transparent electrode 1b, 2b, 6a Leading electrode 3 Sealing material 5 Terminal 6 Transfer 7 LSI chip for driving liquid crystal 20 Wiring crossing means 21, 22 Cross wiring transfer 23 Connection wiring

Claims (4)

[Claims] 1. A first and a second transparent substrate, each having a transparent electrode group formed on one surface thereof, are disposed so as to face each other with a sealing material interposed therebetween. In the liquid crystal display element, a liquid crystal is sealed between the first transparent substrate and a terminal portion having a plurality of routing electrodes drawn out from the transparent electrode group through the sealing material from the transparent electrode group. In the joint surface between the sealing material and the second transparent substrate and in the sealing material, the specific routing electrode jumps to another routing electrode and is connected to an arbitrary transparent electrode on the first transparent substrate side. A liquid crystal display device comprising a wiring cross means. 2. The method according to claim 1, wherein the wiring crossing means is provided between the two transfers for the cross wiring penetrating through the seal material and between the two transfers for the cross wiring at the joint surface between the seal material and the second transparent substrate. 2. The liquid crystal display device according to claim 1, comprising a connection wiring portion formed on the substrate. 3. The liquid crystal display element according to claim 1, wherein an LSI chip for driving a liquid crystal is directly mounted on said terminal portion. 4. The liquid crystal display device according to claim 1, wherein a TCP substrate on which a liquid crystal driving LSI chip is mounted is connected to the terminal portion.