JP2003322873A - Liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid connection failure cause by elongation of a flexible board at the time of thermally press-fitting the flexible board on a liquid crystal panel via an anisotropic conductive film. <P>SOLUTION: Lead electrodes 13 of a terminal part 11a of a liquid crystal panel 10 are arranged so as to include compensation electrode groups PR, PL wherein the adjacent electrodes gradually increase or decrease in length in the order of the arrangement and each tip of those electrodes is also provided with a branch electrode 14 of a length longer than the width between adjacent electrodes in the same direction almost rectangular thereto. Lead electrodes 21 on the side of a substrate 20 are arranged so as to include compensation electrode groups FR, FL which are arranged oppositely to the above displacement compensation electrode groups PR, PL whose adjacent electrodes gradually increase or decrease in length oppositely to the arrangement on the panel, and the electrodes are provided at each tip with a 2nd branch electrode 22 of the length same as that of the 1st branch electrode 14 in the opposite direction almost rectangular thereto. Each electrode in those displacement compensation electrode groups is arranged so as to be relatively moved by the length of the branch electrode. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal panel with TC.
The present invention relates to a liquid crystal display element in which a flexible substrate including P is connected to form a module, and more specifically, to a deviation compensating means at the time of connection by thermocompression.

[0002]

2. Description of the Related Art One of the processes for producing a liquid crystal display element (liquid crystal module) is a process for attaching a flexible substrate to a liquid crystal panel. An example of the process is shown in FIGS.
Will be described.

The liquid crystal display panel 10 is formed by pressing a pair of transparent electrode substrates 11 and 12 by pressure bonding via a peripheral sealing material (not shown), and at least one transparent electrode substrate 11 has the substrate 11 laterally extended. The terminal portion 11a is provided. As shown in FIG. 5, a large number of lead electrodes 13 connected to the transparent electrodes in the panel are formed in a striped shape (a strip shape) on the terminal portion 11a.

The flexible substrate 2 is attached to the terminal portion 11a.
For example, TCP (tape carrier pa)
and a COF (chip on film) or the like are connected. The TCP or COF is a liquid crystal driving IC (or LSI) chip 23 mounted on a flexible substrate 20 on which a wiring pattern is formed.

Although lead electrodes for signal output and signal input are provided on both sides of the IC chip mounting portion (both ends of the substrate), the terminal portion of the liquid crystal panel 10 therein is shown in FIG. Only the electrode connection portion 20a on the signal output side of the flexible substrate 20 connected to 11a is shown. This electrode connection part 2
0a has a large number of lead electrodes 2 similar to the terminal portion 11a.
1 is formed in a stripe shape (a strip shape).

An anisotropic conductive film (ACF) 31 is often used to connect the terminal portion 11a of the liquid crystal panel 10 and the electrode connecting portion 20a of the flexible substrate 20. The anisotropic conductive film 31 is, for example, a film in which conductive particles are dispersed in a thermosetting resin film, and as shown in FIG. 4, the anisotropic conductive film 31 has a terminal portion 11 a of the liquid crystal panel 10 and an electrode connecting portion 20 a of the flexible substrate 20. By sandwiching it and pressing it with the thermocompression bonding head 32, conductivity in a single direction is exhibited, and conduction is established between the extraction electrode 13 of the liquid crystal panel 10 and the lead electrode 21 of the flexible substrate 20.

By the way, since the flexible substrate 20 (in this example, TCP is shown) uses a synthetic resin film such as polyimide as a base material (base film),
The glass substrate of the liquid crystal panel 10 is more likely to be thermally expanded and stretched by heating. The elongation due to this heat is caused by the electrode connecting portion 20a.
It becomes remarkable as it goes to the left and right ends.

Therefore, the extraction electrode 1 of the liquid crystal panel 10
3 and the lead electrodes 21 of the flexible substrate 20 are designed to have exactly the same pitch, not only the lead electrode 13 and the lead electrode 21 are displaced during thermocompression bonding but the reliability of the connection is impaired. In extreme cases, poor connection may result.

Therefore, some measures have been taken to prevent this displacement. As one of them, a method is known in which the pitch of the lead electrodes 21 is narrowed in advance at the design stage in consideration of the expansion of the flexible substrate 20.

However, in the method of changing the pitch in advance, the elongation rate varies depending on the material of the base film, so that it has to be redesigned every time the material changes, and the elongation may not be as calculated. Have problems such as.

[0011]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to ensure that a good connection state can be obtained even if the flexible substrate extends.

[0012]

In order to solve the above problems, the present invention is directed to a liquid crystal panel having a terminal portion formed with a plurality of stripe-shaped extraction electrodes and facing each of the extraction electrodes. A liquid crystal display device comprising: a flexible substrate having a plurality of formed lead electrodes, wherein the lead electrode and the lead electrode are connected via a predetermined electric connection means (for example, an anisotropic conductive film), A. The extraction electrode, the length of the adjacent electrodes are different so as to gradually decrease or increase along the arrangement order,
And a panel side deviation compensating electrode group in which first branch electrodes having a length larger than the inter-electrode width are formed at substantially right angles in the same direction at the respective tips of the electrodes, B. The lead electrode is arranged so as to face the panel side deviation compensating electrode group, and the lengths of the adjacent electrodes are different so as to gradually increase or decrease in the opposite order to the panel side in the order of arrangement thereof, In addition, a substrate side deviation compensating electrode group in which a second branch electrode having the same length as the first branch electrode is formed at a substantially right angle in a direction opposite to the first branch electrode is included at each tip of the electrodes. C. Each electrode in the panel side deviation compensating electrode group and each electrode in the substrate side deviation compensating electrode group are arranged relatively displaced by the width of the electrode and the length of the branch electrode. It is characterized by being.

The structure of the panel side deviation compensating electrode group may be applied to all of the lead electrodes, and the structure of the substrate side deviation compensating electrode group may be applied to all of the lead electrodes. In terms of the design, it is preferable to provide each of the compensation electrode groups on the end portion side of the flexible substrate, where the flexible substrate is greatly stretched by heat.

The length of the branch electrodes is preferably equal to or greater than the interelectrode width, but from the viewpoint of designing the electrodes, it is particularly preferable that the length of the branch electrodes is an integral multiple of the interelectrode width. preferable.

Further, as another feature of the present invention, at least one of the extraction electrode or the lead electrode has a different length of adjacent electrodes, and each tip of these electrodes has a length shorter than the inter-electrode width. A deviation compensating electrode group in which the branch electrodes are formed at substantially right angles in the same direction may be included.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described. First, as a first embodiment, FIG. 1A shows a schematic enlarged plan view of a panel side deviation compensating electrode group formed on the terminal portion 11a side of the liquid crystal panel 10, and FIG.
FIG. 3 is a schematic enlarged plan view of a substrate side deviation compensating electrode group formed on the electrode connecting portion 20a side of the flexible substrate 20.

FIG. 1A includes two panel side deviation compensation electrode groups, one group of which is referred to as a panel side first deviation compensation electrode group PR, and the other group of which is referred to as a panel side. The second deviation compensating electrode group PL is.

In the first embodiment, the first displacement compensation electrode group PR is actually the right end side of the terminal portion 11a,
The second displacement compensation electrode group PL is disposed on the left end side of the terminal portion 11a, but in FIG. 1A, the intermediate extraction electrode 13 (see FIG.
(See reference) is omitted, and both shift compensation electrode groups PR and PL are shown close to each other.

In the first embodiment, the first displacement compensating electrode group PR includes three extraction electrodes 13x, 13y, 13z, and the second displacement compensating electrode group PL has the same structure. Book extraction electrodes 13a, 13b, 13c are included. Since the first displacement compensation electrode group PR and the second displacement compensation electrode group PL are bilaterally symmetrical, the first displacement compensation electrode group PR will be mainly described.

The three extraction electrodes 13x, 13y, 13z of the first displacement compensation electrode group PR have different lengths in the order of arrangement. Here, the arrangement order of the electrodes is shown in FIG.
In the case of (a) from left to right, the length of the first displacement compensation electrode group PR is gradually shortened in the order of the extraction electrodes 13x → 13y → 13z. The length of the extraction electrode is a length that is linearly drawn from the peripheral sealing material (not shown) of the liquid crystal panel 10 toward the edge of the terminal portion.

Branch electrodes 14x, 14y, and 14z are formed at the tips of the extraction electrodes 13x, 13y, and 13z so as to be substantially perpendicular to each other. Both directions are the same,
In this example, the direction is right in FIG. 1A, that is, the right side direction of the terminal portion 11a.

The length of each branch electrode 14x, 14y, 14z is preferably longer than the interelectrode width W. Here, assuming that the arrangement pitch of the extraction electrodes is P and the inter-electrode width W is P / 2, which is half thereof, in this example, the length of each branch electrode 14x, 14y, 14z is equal to the inter-electrode width W. It is twice, that is, the length P for one pitch.

According to this, for example, the branch electrode 14x of the extraction electrode 13x extends to the tip side of the extraction electrode 13y on the right side thereof, but the extraction electrodes 13x, 13y, 1
By properly selecting the length of 3z and the width of the branch electrodes 14x, 14y, 14z, electrical insulation between them can be secured.

Extraction electrode 1 in the second displacement compensation electrode group PL
The lengths of 3a, 13b, and 13c gradually increase in the order of arrangement of the electrodes, which is opposite to the first displacement compensation electrode group PR. That is, the extraction electrode 13a → 13b → 1
The length gradually becomes longer in the order of 3c.

Branch electrodes 14a, 14b, 14c are also formed at the tips of the extraction electrodes 13a, 13b, 13c so as to be at a substantially right angle, but the direction thereof is different from that of the first displacement compensation electrode group PR. In the opposite direction, to the left in FIG. 1 (a),
That is, it is the left side direction of the terminal portion 11a. Other requirements are the same as those of the first displacement compensation electrode group PR. The branch electrodes 14a, 14b, 14c, the branch electrodes 14x, 14y,
14z corresponds to the first branch electrode of claim 1.

Next, with reference to FIG. 1B, a substrate side deviation compensating electrode group formed in the electrode connecting portion 20a of the flexible substrate 20 will be described. FIG. 1B also includes two substrate-side displacement compensation electrode groups, one of which is the substrate-side first displacement-compensation electrode group FR and the other is the substrate-side second compensation electrode group FR. A deviation compensation electrode group FL is used.

The first deviation compensating electrode group FR has a corresponding relationship with the panel side first deviation compensating electrode group PR, and the second
The deviation compensation electrode group FL is in a corresponding relationship with the second deviation compensation electrode group PL on the panel side. Therefore, also in FIG. 1B, the intermediate lead electrode 21 (see FIG. 5) is omitted.

The first displacement compensating electrode group FR includes three lead electrodes 21x, 21y, 21z, and
The second displacement compensation electrode group FL also includes three lead electrodes 21a, 21b, 21c. Since the first displacement compensation electrode group FR and the second displacement compensation electrode group FL are bilaterally symmetrical, the first displacement compensation electrode group FR will be mainly described.

The lengths of the three lead electrodes 21x, 21y, 21z of the first displacement compensating electrode group FR also differ according to the arrangement order, but in this case, the lead electrode 2
Contrary to the lead-out electrodes 13x, 13y, 13z on the panel side, which are in a corresponding relationship, 1x, 21y, 21z are gradually lengthened in the order of lead electrodes 21x → 21y → 21z in the order in which the electrodes are arranged. ing.

Branch electrodes 22x, 22y, and 22z are also formed at the tips of the lead electrodes 21x, 21y, and 21z so as to be substantially right angles. Although the directions are the same, they are opposite to the branch electrodes 14x, 14y, 14z on the panel side and are leftward in FIG. 1B, that is, the left side direction of the electrode connecting portion 20a.

The length of each branch electrode 22x, 22y, 22z is the same as the length of the branch electrode 14x, 14y, 14z on the panel side, and in this example, it is twice the interelectrode width W, that is, one pitch. The length is P.

The lead electrodes 21a, 21b, 21c in the second displacement compensating electrode group FL are arranged in the order in which the electrodes are arranged, as opposed to the lead-out electrodes 13a, 13b, 13c on the panel side, which are in a corresponding relationship therewith. Electrodes 21a → 21b → 21c
The length is gradually shortened in the order of.

Further, the lead electrodes 21a, 21b, 21c
Branch electrodes 22a, 22b, 22c are also formed at each tip so as to have a substantially right angle, but the direction thereof is opposite to that of the branch electrodes 14a, 14b, 14c on the panel side, as shown in FIG.
In the right direction, that is, the right side direction of the electrode connecting portion 20a. The branch electrodes 22a, 22b, 22c and the branch electrodes 22x, 22y, 22z correspond to the second branch electrode in claim 1.

Each lead electrode of the first displacement compensation electrode group PR on the panel side and each electrode of the first displacement compensation electrode group FR on the substrate side are three times the inter-electrode width W, that is, 1.5 pitches. The placement is relatively even by the length. Similarly, the lead-out electrodes of the second displacement compensation electrode group PL on the panel side and the electrodes of the second displacement compensation electrode group FL on the substrate side have a width W of 3 between electrodes.
The arrangement is relatively even doubled, that is, a length corresponding to 1.5 pitches.

That is, the panel-side lead electrode 13x and the substrate-side lead electrode 21x which are connected to each other will be described as an example. The substrate-side lead electrode 21x is separated from the panel-side lead electrode 13x by an inter-electrode width W. 3 times the length (in this example, the length P for 1.5 pitches) is shifted to the right.

Further, the panel-side lead electrode 13c and the substrate-side lead electrode 21c which are connected to each other will be described as an example. The substrate-side lead electrode 21c is separated from the panel-side lead electrode 13c by an inter-electrode width W. Is shifted to the left by a length three times (in this example, a length P corresponding to 1.5 pitches).

In order to connect the liquid crystal panel 10 and the flexible substrate 20, the branch electrodes 14 on the panel side and the branch electrodes 22 on the substrate side are aligned and, for example, an anisotropic conductive film 31 (Fig. (See 4), and thermocompression bonding is performed.

As described above, in this example, the branch electrodes 14,
22 has a length P for one pitch. Therefore,
Even if the flexible substrate 20 is stretched by heating, if the stretch is within the length P for one pitch, electrical connection will be maintained.

Thus, the lengths of the branch electrodes 14 and 22 are
Although it may be arbitrarily determined according to the deviation allowable value, it is preferably an integral multiple of the inter-electrode width W in consideration of the ease of electrode design. As another example, regarding the first displacement compensation electrode group PR on the panel side and the first displacement compensation electrode group FR on the substrate side, the lengths of the branch electrodes 14 and 22 are shown in FIGS. 2A and 2B. An example in which the width W between the electrodes is one time is shown.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3A shows the panel side first displacement compensation electrode group PR according to the second embodiment, and FIG.
Is a first displacement compensation electrode group F on the opposite side of the substrate.
R is shown. The second deviation compensation electrode group PL on the panel side and the second deviation compensation electrode group FL on the substrate side (not shown) are bilaterally symmetrical to the first deviation compensation electrode groups PR and FR.

In the second embodiment, for example, the branch electrodes 14x, 14y, only for the extraction electrodes 13x, 13y, 13z included in the first displacement compensation electrode group PR on the panel side.
14z is formed. Also in this case, the branch electrode 14
The directions and lengths of x, 14y, and 14z are the same,
The length is not more than the width W between the electrodes. Lead electrodes 21x, 21y, 21 included in the first displacement compensation electrode group FR on the substrate side
No branch electrode is formed for z.

The lengths of the extraction electrodes 13x, 13y, 13z and the lead electrodes 21x, 21y, 21z are, for example, gradually shortened in the arrangement order of the electrodes for the extraction electrodes 13x, 13y, 13z as in the first embodiment. And the lead electrodes 21x, 21y, 21z,
The electrodes are formed so as to gradually become longer along the arrangement order of the electrodes. Also in the second embodiment, as can be seen from the description of the first embodiment, the length of the branch electrode 14 is within the deviation allowable range.

According to the second embodiment, the extraction electrodes 13x, 13y, 13z and the lead electrodes 21x, 2 are formed.
It is not always necessary to gradually decrease or gradually increase the lengths of 1y and 21z along the order in which the electrodes are arranged. For example, the lengths may be the same or may be arranged in a staggered manner, but from the viewpoint of improving the reliability of electrical insulation between the electrodes, It is preferable to gradually decrease or increase according to the arrangement order of the electrodes.

The specific structure of the present invention has been described above with reference to the first and second embodiments, but the panel side deviation compensating electrode group and the substrate side deviation compensating electrode group may be interchanged. Further, the structure of the present invention can be applied to all of the lead-out electrode on the panel side and the lead electrode on the substrate side. Further, the number of electrodes included in each displacement compensation electrode group can be set as necessary.

[0045]

As described above, according to the present invention,
When a flexible substrate having a lead electrode on a terminal portion of a liquid crystal panel on which a lead electrode is formed is thermocompression-bonded through, for example, an anisotropic conductive film, a good connection state is obtained even if the flexible substrate is stretched by heating. Can be secured,
It is possible to easily set the allowable range of deviation between the lead electrode of the liquid crystal panel and the lead electrode of the flexible substrate.

[Brief description of drawings]

FIG. 1A is an enlarged plan view schematically showing a displacement compensation electrode group provided on a liquid crystal panel side as a first embodiment of the present invention, and FIG. 1B is a substrate side displacement compensation electrode group as a counterpart thereof. Similarly, the enlarged sectional view shown typically.

FIG. 2 is a diagram schematically showing a modified example of the first embodiment.
FIG.

FIG. 3A is an enlarged plan view schematically showing a deviation compensation electrode group provided on the liquid crystal panel side as a second embodiment of the present invention, and FIG. 3B shows a deviation compensation electrode group on the substrate side as its counterpart. Similarly, the enlarged sectional view shown typically.

FIG. 4 is a schematic side view for explaining a method of connecting a liquid crystal panel and a liquid crystal drive circuit board.

FIG. 5 is a schematic plan view showing a terminal portion of a liquid crystal panel and a connection portion of a liquid crystal drive circuit board side by side.

[Explanation of symbols]

10 LCD panel 11a terminal part 13 (13a to 13c, 13x to 13z) Extraction electrode 14 (14a-14c, 14x-14z) Branch electrodes 20 TCP substrate (flexible substrate) 20a Electrode connection part 21 (21a to 21c, 21x to 21z) Lead electrode 22 (22a-22c, 22x-22z) Branch electrode Width between W electrodes

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H092 GA32 GA33 GA34 GA37 GA38                       GA49 GA50 GA51 GA55 GA57                       HA12 HA25 JB71 JB74 MA32                       NA15                 5E348 AA02 AA09 AA30 EF04 EF12                       FF01

Claims (4)

[Claims] 1. A liquid crystal panel having a terminal portion in which a plurality of striped lead-out electrodes are formed, and a flexible substrate having a plurality of lead electrodes formed so as to face each of the lead-out electrodes, In a liquid crystal display element in which the extraction electrode and the lead electrode are connected via a predetermined electrical connection means, the extraction electrode is configured such that the length of adjacent electrodes is gradually reduced or gradually increased along the arrangement order. A panel side deviation compensating electrode group in which first branch electrodes having different lengths and having a length larger than the interelectrode width are formed at substantially right angles in the respective tips of the electrodes is included. The lead electrodes are arranged to face the panel side deviation compensating electrode group so that the lengths of adjacent electrodes gradually increase or decrease in the opposite order to the panel side in the order of arrangement. It is, and the first to the tips of the electrodes
The second side branch electrode having the same length as the side branch electrode includes a substrate side deviation compensation electrode group in which the second branch electrode is formed substantially at a right angle in a direction opposite to the first branch electrode, and the panel side deviation compensation is performed. Each electrode in the electrode group and each electrode in the substrate side deviation compensating electrode group are arranged so as to be relatively offset by the width of the electrode and the length of the branch electrode. Liquid crystal display device. 2. The liquid crystal display element according to claim 1, wherein each of the compensation electrode groups is arranged on both ends of a terminal portion of the liquid crystal panel and a lead electrode portion of the flexible substrate. 3. The liquid crystal display element according to claim 1, wherein the length of the branch electrode is an integral multiple of the inter-electrode width. 4. A liquid crystal panel having a terminal portion on which a plurality of striped extraction electrodes are formed, and a flexible substrate having a plurality of lead electrodes formed so as to face each of the extraction electrodes, In a liquid crystal display element in which the extraction electrode and the lead electrode are connected via a predetermined electrical connection means, at least one of the extraction electrode or the lead electrode, the length of adjacent electrodes is different, and, A liquid crystal display element, characterized in that each tip of these electrodes includes a shift compensating electrode group in which branch electrodes having a length shorter than the inter-electrode width are formed substantially at right angles in the same direction.