JP2548560B2 - Liquid crystal display device and its alignment method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device capable of accurately aligning a terminal of a liquid crystal display device with a terminal of an external connection substrate, and an alignment method using the same. Is.

[Prior Art] Conventionally, in order to align the terminals of the liquid crystal display device and the terminals of the external connection substrate, the alignment was performed visually. However, as the display density of the liquid crystal display device has increased, the number of electrode terminals has increased remarkably and the pitch of the terminals has become narrower, which causes a problem that a slight misalignment leads to an erroneous display. It has become to.

Therefore, in order to perform this alignment faster and more accurately without relying on visual observation, alignment is performed while electrically measuring. For example, a pair of terminals for alignment is formed on the external connection board, and a corresponding terminal is also formed on the liquid crystal display device facing it, and the conduction is detected to perform the alignment.

[Problems to be solved by the invention] However, the accuracy of the terminal pattern of the external connection board is limited to ± 0.15 mm at most, which is not enough for high density liquid crystal display devices. There is.

As a concrete example of this, there is a large dot matrix display such as 640 × 200 dots, and the number of terminals of this liquid crystal display device tends to increase due to the increase of the display density in the future, and the alignment can be performed with higher accuracy. There was a desire for a method that could be done.

Further, in order to perform the accurate alignment by detecting the electrical continuity as described above, it is necessary to prepare a plurality of continuity detecting means for each device to be aligned, and it is necessary to prepare many continuity detecting means. there were.

[Means for Solving the Problem] The present invention has been made to solve such a problem, and at least one substrate is provided with an electrode-attached substrate having a terminal group of electrodes formed in the peripheral portion thereof on an electrode surface. In a liquid crystal display device in which liquid crystal display devices are arranged so that they face each other, the periphery is sealed, and liquid crystal is filled inside, one or more widths adjacent to the display electrode terminal group and narrower than the display terminal group are provided. The terminal for alignment of is formed, and this terminal for alignment is extended to the inside of the seal to enable the alignment display between the electrodes facing each other except the original display pixel portion. A liquid crystal display device characterized by using the liquid crystal display device, an external connection substrate corresponding to the terminal group of the liquid crystal display device is opposed to the terminal group of the liquid crystal display device, and a voltage is applied between both electrodes. Do the alignment while watching the alignment display. And a method for aligning a liquid crystal display device characterized by the following.

By using the liquid crystal display device and the alignment method of the present invention, even the terminals of the liquid crystal display device for high density display,
It enables easy, accurate and visual alignment.

The liquid crystal display device of the present invention is provided with an In ₂ O ₃ —SnO ₂ (IT
O), glass with electrodes such as SnO ₂ or the like, substrates such as plastic are arranged so that the electrode surfaces face each other, the periphery is sealed with a sealing material, and a known liquid crystal display device in which liquid crystal is filled inside may be used. A color filter, a light-shielding layer, a non-reflective layer, etc. may be formed if necessary.

However, in the peripheral portion of either one of the substrates, a lead of an electrode for display is drawn out to form a terminal group of the electrode. When the number of pixels is large like a dot matrix, this terminal group may be taken out to the side 1 or 2 of both substrates, respectively. It may be a terminal in which terminals are concentrated and taken out on one side of one substrate.

Further, the terminals may be arranged in a stacked manner or may be arranged in a plurality of rows offset from each other, or a plurality of liquid crystal layers may be laminated and the number of substrates is three or more, and the terminals are formed on each substrate. May be.

In the present invention, such a liquid crystal display device is provided with one or more positioning terminals having a width narrower than that of the display terminal group, adjacent to the display electrode terminal group. Is. Then, the terminal for alignment is extended into the seal to enable the alignment display with the electrode opposed to the portion other than the display pixel portion by the original display electrode. This allows you to measure electrical continuity,
The alignment can be easily performed only by visually observing the liquid crystal display device.

In the present invention, the positioning accuracy is obtained by the width and pitch of the terminal for positioning. For this reason, the alignment can be performed with the patterning accuracy of the substrate of the liquid crystal display device that is more accurate than the accuracy of the conventional printed circuit board that is the external connection board.

In particular, the number N of terminals for this alignment is 3 or more,
By arranging them adjacently at a pitch narrower than that of the display terminal group, it becomes possible to perform the alignment more accurately.

Further, in this case, the positioning terminal can be positioned regardless of where it is arranged in the terminal group of the display electrode, but by arranging it outside the terminal group of the display electrode, The alignment terminal and the alignment display section connected to the alignment terminal are less likely to affect the patterning of the display electrode, and the degree of freedom of the display pattern is increased, which is preferable. When the display part is gathered on almost one surface like a dot matrix, arranging terminals not related to display between the terminals disturbs patterning. It is preferable to dispose a terminal for alignment in.

Particularly, by arranging the terminals for alignment on both sides of the terminal group of the electrodes for display, the alignment can be more accurately performed.

In addition, it is preferable that this group of terminals for positioning is composed of five or more terminals for positioning because the positioning is easy.

[Embodiment] Next, a description will be given with reference to the drawings.

FIG. 1 is a plan view showing a typical example of the liquid crystal display device of the present invention, in which electrodes of both substrates are shown, although it is difficult to make a part. FIG. 2 is a plan view of an example of an external connection board connected to this liquid crystal display device. FIG. 3 is an enlarged plan view of a terminal portion for alignment of the liquid crystal display device of FIG. 1 and the external connection board of FIG.

In FIG. 1, reference numeral 1 denotes a first substrate, 2 denotes a second substrate, and a terminal 3 of an electrode for display is provided on the first substrate.
(3A, 3B, ...) and 2 sets of terminal 4 for positioning electrodes
, (4A, 4B, ..., 4E and 4F, 4G, ..., 4J), terminals 5 (5A, 5B, ...) Of display electrodes are formed on the second substrate. In this case, the portion 6 at the intersection of the display electrode on the first substrate and the display electrode on the second substrate serves as a display pixel. In addition, a portion other than these display pixels, which is a portion inside the seal of the liquid crystal display device, at the intersection of the alignment electrode of the first substrate and the display electrode of the second substrate. 7 (7A, 7B, ..., 7E and 7F, 7G, ... 7J) serve as a display unit for alignment. Of course, in this case, an electrode for alignment is also formed on the second substrate, and the portion of the intersection of the electrode for alignment of the first substrate and the electrode for alignment of the second substrate is aligned. It may be used as a display unit.

In addition, in this example, in order to make it easier to understand the lighting state,
The tips of the alignment electrodes are formed like flags along the opposing display electrodes.

Further, in this example, five electrodes for alignment are provided on each side of the display electrode on the first substrate, five electrodes each.

FIG. 2 is a plan view showing an example of an external connection board for connecting to this liquid crystal display device.

In FIG. 2, on the external connection board 11, the same pitch terminals 13 corresponding to the terminals 3 of the display electrodes of the liquid crystal display device are provided.
(13A, 13B, ...) And terminals 14A, 14B for alignment corresponding to the terminals 4 of the two sets of electrodes for alignment are provided.

FIG. 3 is an enlarged plan view of a terminal portion for explaining the step of aligning the liquid crystal display device of FIG. 1 and the external connection substrate of FIG.

The terminal 4 of the alignment electrode on the liquid crystal display device side has a terminal width of W ₁ , a terminal-to-terminal gap of W ₂ , and a pitch of (W ₁ + W ₂ ).

Further, the terminal 3 of the display electrode has a terminal width W ₄ and a gap W ₅ between the terminals, and the pitch thereof is (W ₄ + W ₅ ), and the terminal pitch of the electrode for alignment ( W ₁ + W ₂ ) is narrower than the pitch (W ₄ + W ₅ ) of the terminals of the electrodes for display. This enables highly accurate alignment. Since these electrodes for alignment are used only for alignment, a short circuit may occur between adjacent electrodes,
Even if the electrodes are cut, only care is required at the time of alignment and the display is not affected. Therefore, the electrode width and the electrode gap can be made smaller than the limit of general electrode patterning. For this reason, it is possible to perform the alignment with high accuracy as compared with the case where the alignment is performed using the normal display electrodes.

Specifically, for example, the terminal width W ₄ of the terminal of the electrode for display
Is 300 μm and the gap W ₅ between the terminals is 50 μm, the terminal width W ₁ of the terminal of the alignment electrode is 50 μm, and the gap W ₂ between the terminals may be 20 μm. In this case, the pitch of the terminals of the display electrodes is 350 μm,
The pitch of the terminals of the alignment electrodes is 70 μm. The electrode width and the electrode gap may be appropriately set by making the pitch of the terminals of the positioning electrodes smaller than the pitch of the terminals of the display electrodes.

The terminal of the electrode for display of the external connection substrate facing this is provided at the same pitch and the same number as the terminal of the electrode for display of the liquid crystal display device.

However, the terminal width and the terminal gap of the display electrode terminal do not have to match the terminal width and the terminal gap of the display electrode terminal of the liquid crystal display device. Generally, the patterning accuracy of the electrodes of the external connection substrate is lower than the patterning accuracy of the electrodes of the liquid crystal display device, and the resistance of the electrodes of the external connection substrate is lower than the resistance of the electrodes of the liquid crystal display device. In the case of the electrode, it is preferable that the width of the terminal of the electrode is slightly narrowed and the terminal gap is slightly widened, which makes it safer against misalignment during alignment.

Specifically, for example, when the terminal width W ₄ of the terminal of the display electrode of the liquid crystal display device of the above example is 300 μm and the gap W ₅ between the terminals is 50 μm, the external connection substrate for display is displayed. The terminal width of the electrode terminal is 250 μm, and the gap between the terminals is 100 μm.
It may be set to μm.

Electrode terminals 14A, 14B for positioning of this external connection board
The width W ₃ may be designed within a certain range depending on the width W ₁ of the terminal of the electrode for alignment on the liquid crystal display side, the terminal gap W ₂ and the number of the terminals.

That is, when N (N ≧ 3) positioning terminal groups are formed on the liquid crystal display side, W ₁ ≦ W ₃ <(N−2) · W ₁ +
The width of the terminal of the electrode for positioning the external connection board may be designed so as to be (N-1) · W ₂ .

The number of positioning electrodes in this example is 5, and the terminal width is W ₁ 50.
In case of μm and terminal gap W ₂ 20 μm, 50 μm ≦ W ₃ <230
It may be μm.

In this case, the terminal width W ₃ should be 50 μm on the liquid crystal display side.
Although the position can be adjusted even if the position is narrower, it is difficult to detect the position deviation even if the position is deviated, and the terminal width W of the alignment electrode on the liquid crystal display side is ₁ W or more, in this example 50 μm or more. It is preferable that

When the alignment is completed, the terminal width W ₃ is set to (N− 2) ・ W ₁
It should be less than + (N-1) · W ₂ , and in this example less than 230 μm. However, with this value, there is a risk that the four electrodes will light up due to slight misalignment, so in reality, it is slightly narrower than this (N-2).
About W ₁ + (N−3) · W _2, about 190 μm or less is preferable in this example.

The number of electrodes for alignment on the liquid crystal display device side may be set to one and the terminal width may be made narrower than the terminal width of the electrodes for display, but the alignment process may be a little troublesome. . This is because it is difficult to determine which of the left and right directions the display should be moved to when the alignment display is not lit. Further, it is difficult to make the width of the terminal on the side of the external connection board narrower than the width of the terminal on the side of the liquid crystal display device, so that the alignment accuracy is lowered.

Therefore, assuming that the number of alignment electrodes on the liquid crystal display device side is N (N is an integer equal to or greater than 3), the alignment display parts by the electrodes at both ends do not light up when the alignment is completed. Is preferably set. Accordingly, when the positions are deviated, it is possible to easily determine in which of the left and right directions the movement should be made, and it is possible to easily determine that the alignment is completed.

Particularly, by setting N to 5 or more and the number of electrodes for alignment to 5 or more, it is possible to increase the number of electrodes that are lit up to 3 or more when the alignment is completed, and it is easy to determine the completion of alignment and The width of the terminal for alignment on the connection board side can be widened, the patterning of the electrode on the external connection board side is facilitated, and the alignment accuracy is also improved.

In the example of FIG. ₃ , the alignment state was examined by changing the terminal width W ₃ of the alignment electrode on the external connection board side as follows.

50μm, 80μm, 130μm, 150μm, 190μ
m, 210 μm.

In this example, assuming that the external connection substrate is displaced to the right with respect to the liquid crystal display device, if the displacement is within the range, the display portions of the electrodes for alignment are 1 to 4 on the right side.
The book will light up.

First, when the deviation is large, the maximum is 190μ, respectively.
m, 205 μm, 230 μm, 240 μm, 260 μm,
One electrode A at the right end lights up with a deviation of 270 μm.

In the example, when the external connection board is moved to the left, 120
At the time of deviation of μm, the two right electrodes A and B are turned on,
At 90 μm, the rightmost electrode goes out and only the second electrode B from the right turns on, and at 50 μm, the second electrode from the right and 3
The second electrodes B and C are lit, and at 20 μm, 2 from the right end.
The second electrode is turned off and only the central electrode C is turned on, indicating that the alignment is completed. In this case, because of left-right contrast, the alignment accuracy in this example was ± 20 μm.

In the example, when the external connection board is moved to the left, 135
At the time of deviation of μm, the two right electrodes A and B are turned on,
At the time of 75 μm, the rightmost electrode goes out and only the second electrode B from the right lights up, and at the time of 65 μm, the second electrode from the right and 3
The second electrodes B and C are turned on, and at the time of 5 μm, 2 from the right end.
The second electrode is turned off and only the central electrode C is turned on, indicating that the alignment is completed. The alignment accuracy in this case was ± 5 μm.

In the example, when the external connection board is moved to the left, 160
At the time of deviation of μm, the two right electrodes A and B are turned on,
At the time of 90 μm, the three electrodes A, B, C on the right are turned on, at the time of 50 μm, the electrode A on the right end is turned off and only the second and third electrodes B, C from the right are turned on, At the time of 20 μm, the central three electrodes B, C, and D are turned on, indicating that the alignment is completed. The alignment accuracy in this case is ± 20 μm
Met.

In the example, when the external connection substrate is moved to the left, one to three electrodes are lit up as in the example, and at the time of 30 μm, the central three electrodes B, C and D are lit up, You can see that the matching is complete. The alignment accuracy in this case was ± 30 μm.

In the example, if the external connection board is moved to the left,
The four electrodes are turned on, and at the time of 20 μm, the central three electrodes B, C, and D are turned on, indicating that the alignment is completed. The alignment accuracy in this case was ± 20 μm.

In the example, if the external connection board is moved to the left,
The four electrodes are turned on, and at the time of 10 μm, the central three electrodes B, C, and D are turned on, indicating that the alignment is completed. The alignment accuracy in this case was ± 10 μm.

Among these examples, and in the examples, and, because the width of the terminal of the electrode for positioning the external connection board is narrow, it is somewhat difficult to form it accurately. It is preferable to take. Also, if the terminal width is made wider than this, patterning errors may cause
Even when the alignment is completed, the display portions of four or more electrodes are likely to light up, which may make alignment difficult.

Here, without changing the terminal width and the terminal gap of the above embodiment,
An example in which the number of terminals of the alignment electrodes on the liquid crystal display device side is three is shown.

In this case, the detection limits are 120 μm, 135 μm, 16
It becomes 0 μm, 170 μm, 190 μm, 200 μm, which is considerably narrower than that in the above-mentioned embodiment.

Further, the accuracy at the time of completion of the alignment is ± 20 μm, ± 5 μm, ± 20 μm, ± 30 as in the above-mentioned embodiment.
Although it was μm, in the above-mentioned embodiment, it is indistinguishable from the one in which the four electrodes are turned on and the one in which the three electrodes are turned on, and the accuracy is significantly reduced to ± 50 μm and ± 60 μm. It became a thing.

The terminals of the electrodes for positioning may be formed on only one side of the terminals of the electrodes for display, but it is preferable to form them on both sides because the accuracy is higher.

Also, on the side of the external connection board 11, terminals 14A for alignment,
It is also possible to provide only the terminal 13 connected to the display electrode without providing 14B, and use the terminals at both ends of this terminal 13 for alignment.

In this case, it is not necessary to form a new terminal on the external connection board side by making the space between the display electrode terminal 3 of the board and the positioning electrode terminal 4 as narrow as possible. Therefore, the existing external connection board can be used.

It is assumed that the distance between the display electrode terminal 3 and the positioning electrode terminal 4 on this substrate is 20 μm, which is the same as W ₂ in the above example, and the terminal width W _{4 of the} display electrode terminal 3 is If the terminal width of terminal 13 on the external connection board is the same, it will be 20 in either direction.
If there is a deviation of more than μm, the positioning electrodes will be turned on.

Therefore, when the alignment electrode is turned on, the external connection board is moved in the direction opposite to the turned-on side,
Alternatively, it is moved to the side where the liquid crystal display device is turned on. For example, if three alignment electrodes are lit, 160μ
Since the deviation is m or more and less than 230 μm, the external connection substrate may be moved to the right or the liquid crystal display device may be moved to the left. Then, if the electrodes for alignment are prepared so that they do not light up, they will be in position. In particular, if the electrodes for the left and right alignments are aligned with the intermediate position where the electrodes are turned on, the alignment can be performed quite accurately.

As this external connection substrate, a substrate in which a desired electrode pattern is formed of a conductive material on an insulating substrate such as plastic is usually used, and the terminals of the liquid crystal display device of the present invention, pressure bonding, soldering, conductive anisotropy are used. It may be connected by an adhesive material or the like.

[Advantages of the Invention] The present invention makes it possible to easily and accurately perform alignment by only visually observing a liquid crystal display device without measuring electrical continuity.
It is extremely productive.

Further, the present invention, the terminal for alignment can be aligned regardless of where it is arranged in the terminal group of the electrode for display, and may be formed in a portion that does not cause a problem in the pattern for display. It has a wide range of use. In particular, by arranging the electrodes for display on the outside of the terminal group, the terminals for alignment and the display portion for alignment connected thereto are less likely to affect the patterning of the electrodes for display, and the degree of freedom of the display pattern is improved. Is increased, which is preferable.

Further, by setting the pitch of the terminals of the electrodes for alignment to be narrower than the pitch of the terminals of the electrodes for display, it is possible to perform highly accurate alignment. This is because the electrode for alignment is used only for alignment, and thus it is possible to perform finer patterning than the safe patterning limit that does not cause a normal short circuit or electrode disconnection. That is, these alignment electrodes, if there is a short circuit between adjacent electrodes, or even if the electrodes are cut, it is only necessary to perform alignment while paying attention to that point,
Since it does not become a defective liquid crystal display device as a display defect, the yield of the liquid crystal display device does not decrease. For this reason, it is possible to perform the alignment with higher accuracy than the case where the alignment is performed using the normal display electrodes without lowering the yield of the liquid crystal display device.

Also, by arranging the terminals for alignment on both sides of the terminal group of the electrodes for display, it is possible to reduce the influence of twisting, misalignment other than lateral displacement, and more accurate alignment becomes possible. Become.

There is also an advantage that the conventional external connection board can be used as it is by utilizing the terminals at both ends of the terminal of the display electrode without providing the terminal for alignment on the external connection board.

In addition to the above, the present invention can be applied in various ways within a range that does not impair the effects of the present invention.

[Brief description of drawings]

FIG. 1 is a plan view showing a typical example of the liquid crystal display device of the present invention. FIG. 2 is a plan view of an example of an external connection board connected to this liquid crystal display device. FIG. 3 is an enlarged plan view of a terminal portion for alignment of the liquid crystal display device of FIG. 1 and the external connection board of FIG. 1,2: substrate, 3 (3A, 3B, ...), 5 (5A, 5B, ...): terminal of display electrode, 4 (4A, 4B, ..., 4E and 4F, 4G, ... 4J): position Matching electrode terminal, 6: Display pixel

Claims (10)

(57) [Claims] 1. At least one substrate is provided with electrodes having electrode terminals formed on the periphery so that the electrode surfaces face each other, the periphery is sealed, and liquid crystal is filled inside. In this liquid crystal display device, one or more alignment terminals having a width narrower than that of the display terminal group are formed adjacent to the display electrode terminal group, and the alignment terminals are extended into the seal. Then, the liquid crystal display device is characterized in that it is possible to perform the alignment display with the electrodes facing each other in the portion other than the original display pixel portion. 2. The liquid crystal display device according to claim 1, wherein three or more positioning terminals are provided adjacent to each other and arranged at a pitch narrower than that of the display terminal group. 3. The liquid crystal display device according to claim 1, wherein the terminal for alignment is arranged outside the terminal group of the electrode for display. 4. The liquid crystal display device according to claim 3, wherein the terminals for alignment are arranged on both sides of the terminal group of the electrodes for display, respectively. 5. The liquid crystal display device according to claim 1, wherein the terminal group for positioning is divided into five or more. 6. A substrate with electrodes having terminal groups of electrodes formed on the periphery of at least one substrate is arranged so that the electrode surfaces face each other, the periphery is sealed, and liquid crystal is filled inside. In the method for aligning a liquid crystal display device, the one or more alignment terminals having a width narrower than that of the display terminals are formed adjacent to the terminal group of the display electrodes, and the alignment terminals are sealed. An external connection board that corresponds to the terminal group of this liquid crystal display device is used by using a liquid crystal display device that extends to the inside and enables alignment display with electrodes facing each other in the part other than the original display pixel part. A method of aligning a liquid crystal display device, comprising: opposing a terminal group of the liquid crystal display device, applying a voltage between both electrodes, and performing alignment while watching the alignment display. 7. The liquid crystal according to claim 6, wherein a liquid crystal display device is used in which three or more terminals for alignment are provided adjacent to each other and arranged at a pitch narrower than that of the terminal group for display. Positioning method of display device. 8. A positioning is performed by using an external connection board having one terminal narrower than the width of the positioning terminal group at a position corresponding to the positioning terminal group of the liquid crystal display device. The method for aligning a liquid crystal display device according to claim 7. 9. A terminal width of each terminal of a group of N (N ≧ 3) positioning terminals is set to W _1, and a gap between the terminals is set.
When W ₂ and the width of the terminal for alignment of the external connection board facing this is W ₃ , W ₁ ≤ W ₃ <(N-2) · W ₁ + (N
-3) The method for aligning a liquid crystal display device according to claim 8, wherein W ₂ is set. 10. A method of aligning a liquid crystal display device according to claim 7, wherein N is 5 or more.