JPH10209202A - Liquid crystal display - Google Patents

Abstract

(57) [PROBLEMS] To connect an FPC to a transparent substrate in a liquid crystal display device with high accuracy using a single camera even when the width of the FPC is small. SOLUTION: An electrode terminal group 6 formed on a transparent electrode 2a.
And the electrode terminal group 8 formed at the end of the FPC 4 while using the alignment marks 7 and 9 for alignment.
Conductive connection is made using F3. Since the marks 7 and 9 are provided in the internal regions of the electrode terminal groups 6 and 8, even if there are a plurality of such marks, they can always be included in the field of view of one camera 11, so that the FPC 4
The marks 7, 9 can always be reliably recognized even if the width dimension W of the mark becomes small. In addition, since the FPC 4 is aligned based on the marks provided in the internal regions of the electrode terminal groups 6 and 8,
The alignment accuracy can be improved as compared with the case where the mark is provided outside the electrode terminal group.

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 for displaying visible information such as characters and numerals by modulating light by controlling the orientation of a liquid crystal sandwiched between a pair of translucent substrates. . In particular, the present invention relates to a liquid crystal display device formed by connecting a wiring element such as an FPC (Flexible Printed Circuit) to at least one of the pair of light-transmitting substrates.

[0002]

2. Description of the Related Art Generally, in a liquid crystal display device, a plurality of light-transmitting electrodes are formed on respective surfaces of a pair of light-transmitting substrates to form pixels for liquid crystal display. Then, a liquid crystal driving IC is conductively connected to the translucent electrodes, and a display operation using the liquid crystal is performed by selectively applying a voltage to one of the translucent electrodes by the liquid crystal driving IC. Do.

[0003] Several methods are conventionally known for conductively connecting a liquid crystal driving IC to a translucent electrode. For example, a method using TCP (Tape Carrier Package), a method using COB (Chip On Board), COG
(Chip On Glass) and other various methods. Here, TCP stands for TAB (Tape Autom
ated bonding: tape automated mounting)
This is a wiring board on which an IC chip is mounted on the surface of a flexible printed circuit (C).
The terminal portion of the CP, that is, the terminal portion of the FPC is connected to the light-transmitting substrate of the liquid crystal panel.

[0004] A COB is a wiring board having an IC chip mounted on an insulating substrate. When this is used, the insulating substrate and the light-transmitting substrate of the liquid crystal panel are heat-sealed. Connection through a wiring element such as When COG is used, ACF (Anisotr
An IC chip is directly bonded on a translucent substrate of a liquid crystal panel using an adhesive such as an opic conductive film (anisotropic conductive film). In this case, a wiring element such as an FPC is connected to the light-transmitting substrate of the liquid crystal panel to supply various signals and power to the IC chip.

As described above, regarding the liquid crystal display device,
It is necessary to connect various wiring elements such as FPCs and heat seals to the electrode terminal portions of the transparent substrate. Now, CO
Considering the case of connecting a wiring element such as an FPC to a G-type liquid crystal display device, for example, as shown in FIG. The end 54a of the FPC 54 is connected using an isotropic conductive film 53. A pair of liquid crystal side alignment marks 57 and 5 are provided on the connection portion of the transparent substrate 52a with the liquid crystal side electrode terminal group 56 interposed therebetween.
7 are provided. Also, at the end 54a of the FPC 54,
A pair of wiring side alignment marks 59, 59 are provided with the wiring side electrode terminal group 58 interposed therebetween.

When the FPC 54 is bonded to the transparent substrate 52a, the liquid crystal alignment marks 57, 57 are photographed from the back side (the lower side in the figure) of the transparent substrate 52a using two cameras, for example, CCD cameras 61, 61. Meanwhile, as shown in FIG. 5, the wiring alignment mark 5 on the FPC 54 side is used.
The two are adhered while adjusting the relative positional relationship between the transparent substrate 52a and the FPC 54 so that 9 conforms to a certain positional relationship with the liquid crystal side alignment mark 57. Thereby, the liquid crystal side electrode terminal group 56 of the transparent substrate 52a and F
The wiring side electrode terminal group 58 of the PC 54 is accurately conductively connected.

[0007]

However, in recent years, there has been a strong demand for miniaturization of the driver IC and the liquid crystal display device. Therefore, the connection terminal group of the FPC 54 and the connection terminal group of the liquid crystal display device 51 are also as small as possible. It is required to fit in the area. To meet this demand, F
The width W of the PC 54 must be reduced, and if so, the interval between the alignment marks 57 and 59 must also be reduced. When a pair of alignment marks 57 and 59 are photographed using two cameras 61 and 61 as in the related art, a pair of alignment marks 57 and 59 are used as described above.
When the interval of 59 is reduced, the interval between the two cameras must be reduced in accordance with the narrowing of the marks. However, there is a limit in reducing the distance between the cameras 61, 61. When the distance between the pair of alignment marks 57, 59 becomes narrower than the limit dimension, the distance between the two cameras cannot be reduced sufficiently and each alignment mark cannot be narrowed. There has been a problem that the mark cannot be recognized.

In the case where the distance between the two cameras cannot be reduced as described above, one camera is removed and the remaining one is removed.
A method of performing alignment by photographing only one of the pair of alignment marks using one camera is also conceivable. However, in that case, the alignment is performed based on one alignment mark provided at a position far away from the center position of the FPC 54,
In this method, there is a problem that the accuracy of positioning of the FPC 54 is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems. Even when the size of a wiring element such as an FPC is reduced, the wiring element is required to be higher than the light-transmitting substrate. The purpose is to be able to align with precision.

[0010]

In order to achieve the above object, a liquid crystal display device according to the present invention comprises a pair of translucent substrates which are opposed to each other across a liquid crystal and at least one of which has a liquid crystal side electrode terminal group. And a wiring element having a wiring-side electrode terminal group, wherein the liquid crystal-side electrode terminal group and the wiring-side electrode terminal group are conductively connected to each other. A liquid crystal side alignment mark is formed in a region, and a wiring side alignment mark is provided in an inner region of the wiring side electrode terminal group.

In this liquid crystal display device, the translucent substrate and the wiring element are joined in a state where the liquid crystal side alignment mark and the wiring side alignment mark are matched with a predetermined relative positional relationship. Thus, the liquid crystal side electrode terminal group and the wiring side electrode terminal group can be conductively connected accurately without displacement.

Further, since the liquid crystal side alignment mark is provided in the internal area of the liquid crystal side electrode terminal group and the wiring side alignment mark is provided in the internal area of the wiring side liquid crystal terminal group, a plurality of such marks are provided. , The marks can always be in the field of view of one camera. As a result, even when the size of a wiring element such as an FPC becomes very small, the alignment mark can always be reliably recognized by the single camera. Moreover, since the positioning of the wiring element is performed based on the alignment mark provided in the internal region of the electrode terminal group, the accuracy of the positioning is improved as compared with the case where the alignment mark is provided outside the electrode terminal group.

In the above structure, the "translucent substrate"
This means that it includes both the case of being colorless and transparent and having a light-transmitting property and the case of being colored and having a light-transmitting property. The term “wiring element” means an element for wiring connected to the light-transmitting substrate irrespective of shape, material, and structure. For example, FPC (Flex
ible printed circuit), a non-flexible printed circuit board, or any other wiring element.

The liquid crystal side alignment mark and the wiring side alignment mark can be formed by deforming the individual electrode terminals constituting the electrode terminal group, or the alignment marks can be formed separately from the individual electrode terminals. Can also be formed. However, with regard to the electrode terminal group formed in a normal liquid crystal display device, the interval between the individual electrode terminals constituting the electrode terminal group is set to be very narrow. It is considered to be quite difficult to set up.

Next, as a method of deforming the electrode terminal,
It is conceivable to form a projecting portion on the electrode terminal and deform it, or to form a notch on the electrode terminal and deform it. As described above, considering that the distance between the electrode terminals adjacent to each other is narrow, it is more preferable to form the cutout portion in the electrode terminal than to form the overhang portion in the electrode terminal. Conceivable.

Each of the above alignment marks is usually C
It is observed using a camera such as a CD camera. In this case, only one alignment mark can be provided in the field of view of the camera, or a plurality of alignment marks can be provided. In addition, when only one is used, a positional deviation between a wiring element such as an FPC and the light-transmitting substrate, particularly a positional deviation due to an inclination is likely to occur. In contrast, if a plurality of alignment marks are provided in one camera field of view,
It is possible to reduce the positional deviation with respect to the inclination.

Further, when a plurality of alignment marks are provided in one camera field of view, alignment is performed at two electrode terminals located farthest from each other among a plurality of electrode terminals included in one camera field of view. It is desirable to provide a mark. In this way, it is possible to determine the positional deviation related to the inclination with the highest accuracy.

Next, a plurality of electrode terminals included in both the liquid crystal side electrode terminal group formed on the transparent substrate and the wiring side electrode terminal group provided in the wiring element are provided with a liquid crystal display. Various electrode terminals such as a signal transmission electrode terminal for transmitting a signal for performing the operation, a power supply electrode terminal for supplying power serving as a power supply for various operations, and a dummy terminal are included. In the liquid crystal display device of the present invention, each alignment mark of the liquid crystal side alignment mark and the wiring side alignment mark deforms an electrode terminal other than the power supply electrode terminal, for example, a signal transmission electrode terminal or a dummy terminal. It is desirable to form by this.

The reason is as follows. That is, if a deformation such as a notch is provided in an electrode terminal to form an alignment mark, the resistance value of the electrode terminal changes. In this case, if the electrode terminal is a signal transmission electrode terminal, the change in the output signal is within the allowable range even if the resistance value changes. Further, if the electrode terminal is a dummy terminal, the change in the resistance value does not matter. In contrast,
When the electrode terminal to be deformed is a power supply electrode terminal, the voltage drop may be out of an allowable range due to a change in the resistance value of the electrode terminal. Therefore, it is desirable that the alignment mark is formed by deforming the electrode terminal for signal transmission or the dummy terminal.

If the alignment marks are provided in both the internal area of the liquid crystal side electrode terminal group and the internal area of the wiring side electrode terminal group as in the present invention, the alignment marks are used to form the transparent substrate of the liquid crystal panel. The wiring elements such as FPC can be positioned with high accuracy. However,
In addition to the alignment marks inside the electrode terminal group, a liquid crystal side auxiliary alignment mark is provided on the translucent substrate outside the liquid crystal side electrode terminal group, and further on the wiring element outside the wiring side electrode terminal group. May be provided with a wiring-side auxiliary alignment mark. In this case, one or both of the main alignment mark inside the electrode terminal group and the auxiliary alignment mark outside the electrode terminal group can be freely selected in accordance with a request from the inspection device side, and the light transmitting substrate and the wiring can be selected. Alignment with the working element can be performed.

[0021]

FIG. 1 shows an embodiment of a liquid crystal display device according to the present invention. This liquid crystal display device includes a liquid crystal panel 1 and F as a wiring element connected thereto.
It has PC4. The liquid crystal panel 1, as shown in FIG.
A pair of transparent substrates (that is, translucent substrates) 2a joined by a sealing material 13 while maintaining a constant gap, that is, a cell gap, by the bead-shaped spacers 12
And 2b. Liquid crystal 14 is sealed in the cell gap.

Polarizing plates 20, 20 are adhered to the outer surfaces of the transparent substrates 2a and 2b. The inner surfaces of the transparent substrates 2a and 2b are respectively provided with ITO (Indium Tin O2).
xide: indium tin oxide) forms transparent electrodes 16a and 16b in a predetermined pattern. These transparent electrodes 16a and 16b are composed of a plurality of IC output electrode terminals 16 formed on a protruding portion 2c of the transparent electrode 2a that protrudes outside the other transparent electrode 2b, that is, an IC output electrode terminal group 16 Is conducted. In addition, the substrate overhang portion 2c
A liquid crystal side electrode terminal group 6 composed of a plurality of IC input electrode terminals is formed at an end of the liquid crystal display.

A liquid crystal driving IC 17 is directly adhered to the substrate overhang portion 2c using an ACF 18. That is, a COG structure is formed. The ACF 18 is formed by dispersing conductive particles in a resin film, and the liquid crystal driving IC 1 is formed by curing the resin portion.
Then, the bumps 19 of the liquid crystal driving IC 17 and the IC output electrode terminal group 16 and the bumps 19 and the liquid crystal side electrode terminal group 6 are conductively connected by conductive particles.

Returning to FIG. 1, a liquid crystal side alignment mark 7 is provided on the substrate located in the internal region of the liquid crystal side electrode terminal group 6 formed on the substrate overhang portion 2c. Also, F
The wiring-side alignment mark 9 is provided on the FPC 4 located in the internal region of the wiring-side electrode terminal group 8 formed at the connection end 4a of the PC 4. In addition, the liquid crystal side auxiliary alignment marks 21, 21 are provided on the substrate outside the liquid crystal side electrode terminal group 6.
1 and A outside the wiring-side electrode terminal group 8.
Wiring side auxiliary alignment marks 22 are provided on CF4.

As shown in FIG. 2, the liquid crystal side alignment mark 7 is formed by providing notches in two electrode terminals 6a, 6a of a plurality of electrode terminals constituting the liquid crystal side electrode terminal group 6. Is done. Further, the wiring-side alignment mark 9 is formed by providing a cutout portion in two electrode terminals 8 a, 8 a of the plurality of electrode terminals constituting the wiring-side electrode terminal group 8. In the drawing, a portion indicated by a chain line A indicates that a plurality of electrode terminals are arranged at substantially equal intervals, but illustration thereof is omitted.

The liquid crystal side electrode terminal group 6 and the wiring side electrode terminal group 8 include various electrode terminals such as a signal transmission electrode terminal, a power supply electrode terminal, and a dummy terminal. In the present embodiment, among those electrode terminals,
In particular, each alignment mark 7 and 9 is formed on a signal transmission electrode terminal or a dummy terminal. The reason is that even if the resistance value of the electrode terminal changes due to the formation of the notch, if the electrode terminal is a signal transmission electrode terminal or a dummy terminal, the resistance value is lower than that of the power supply terminal. This is because the influence of the change is small.

In this embodiment, the liquid crystal side alignment mark 7 is attached to the two electrode terminals 6a, 6a farthest from a plurality of electrode terminals included in the field of view B (FIG. 2) of one CCD camera. It is provided. Inevitably, the wiring-side alignment mark 9 is also provided on the two electrode terminals 8a, 8a which are farthest from among the plurality of electrode terminals included in the camera view B.

Returning to FIG. 1, the transparent substrate 2 of the liquid crystal panel 1
When connecting the FPC 4 to the tip electrode terminal of the overhanging portion 2c, first, the ACF 3 is attached to the tip electrode terminal. Then, one CCD camera 11 is arranged on the back surface (the lower surface in the figure) of the tip electrode terminal portion. Then, while photographing the vicinity of the liquid crystal alignment mark 7 by the CCD camera 11, the connection end 4a of the FPC 4 is carried to the leading end of the substrate overhang 2c. Then, in FIG. 2, after adjusting the position of the FPC 4 or the transparent substrate 2a so that the wiring side alignment mark 9 exactly matches the liquid crystal side alignment mark 7, the FPC 4 is pressed against the transparent substrate 2a with the ACF 3 interposed therebetween. Is cured by heating or the like. As a result, the wiring-side electrode terminal group 8 of the FPC 4 and the liquid-crystal-side electrode terminal group 6 of the transparent substrate 2a are accurately aligned and conductively connected, and then the FPC 4 is bonded to the transparent plate 2a.

In this embodiment, the electrode terminal groups 6, 8
In addition to the provision of alignment marks 7 and 9 in the internal region, auxiliary alignment marks 21 and 22 are provided outside the electrode terminal groups 6 and 8, so that if necessary, the auxiliary alignment marks 21 and 22 are provided. Marks 21 and 2
2, the FPC 4 and the transparent substrate 2a can be aligned. In this case, it is possible to perform more accurate positioning. However, the auxiliary alignment marks 21 and 22 need not always be provided.

As described above, in the present embodiment, the liquid crystal side alignment mark 7 is provided in the internal area of the liquid crystal side electrode terminal group 6, and the wiring side alignment mark 9 is provided in the internal area of the wiring side liquid crystal terminal group 8. Therefore, even when a plurality of these marks are present (four in each of the above embodiments), these marks can always be included in the field of view of one CCD camera 11. As a result, even when the width dimension W of the FPC 4 becomes very small, the alignment marks 7 and 9 can always be reliably recognized by the single camera. Further, an alignment mark 7 provided in an inner region of the electrode terminal groups 6 and 8 is provided.
Since the alignment of the FPC 4 is performed on the basis of the alignment marks 9 and 9, the alignment accuracy can be improved as compared with the case where the alignment marks 7 and 9 are provided outside the electrode terminal groups 6 and 8.

When an alignment mark is arranged outside the electrode terminal group as in a conventional liquid crystal display device, the electrode terminal group is arranged to secure a place for arranging the alignment mark. Location may be restricted. On the other hand, in the present embodiment, since the alignment marks 7 and 9 are provided on the substrate in the internal region of the electrode terminal groups 6 and 8, the arrangement of the electrode terminal groups 6 and 8 is caused by providing the alignment marks. The inconvenience that the position is restricted does not occur, and therefore, the pattern design of the electrode terminal groups 6 and 8 can be freely performed.

The alignment marks 7, 9 are not provided on one electrode terminal, but are provided on two electrode terminals, respectively. Therefore, the alignment marks 7, 9 are provided in the horizontal direction between the FPC 4 and the transparent substrate 2a. In addition to the positional deviation in the vertical direction, the positional deviation in the inclined direction can be accurately determined. Further, in this embodiment, the field of view B of one CCD camera 11
Since the alignment marks 7 and 9 are arranged as far apart from each other as possible, the position can be adjusted with high accuracy by one CCD camera 11 as compared with the case where they are arranged close to each other.

Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to the embodiments and can be variously modified within the technical scope described in the claims.

For example, in the embodiment shown in FIG. 1, the number of the alignment marks 7 on the liquid crystal side and the number of the alignment marks 9 on the wiring side are each four, but these may be one by one or a plurality other than four. You can also. However, it is necessary to pay attention to the possibility that the accuracy of the alignment of the FPC 4 may be deteriorated when one FPC 4 is used.

In the embodiment shown in FIG. 1, an overhang 2c is formed on one of the transparent substrates 2a.
Although the case where the FPC 4 is connected to c is described as an example, in the liquid crystal display device, an overhang is formed on the other transparent substrate 2b in addition to the transparent electrode 2a, and the FPC is connected to the overhang. Some are in the form. For such a type of liquid crystal display device, alignment marks are provided on both transparent substrates.

The alignment marks 7 and 9 shown in FIG. 2 are formed by forming notches in the electrode terminals. Alternatively, the alignment marks 7 and 9 may be formed by forming protrusions in the electrode terminals. Alternatively, the alignment mark can be formed independently of the electrode terminal. However, since the interval between a pair of electrode terminals adjacent to each other is very small,
Forming overhangs or unique alignment marks within this interval may be quite difficult. On the other hand, when a notch is formed in an electrode terminal, there is no need to worry about the size of the gap between the electrode terminals, which is very convenient as a method for forming an alignment mark.

[0037]

According to the liquid crystal display device of the first aspect,
The liquid crystal side alignment mark is provided in the internal area of the liquid crystal side electrode terminal group, and the wiring side alignment mark is provided in the internal area of the wiring side liquid crystal terminal group. Is always within the field of view of one camera. As a result, even when the size of a wiring element such as an FPC becomes very small, the alignment mark can always be reliably recognized by the single camera. Further, since the positioning of the wiring element is performed based on the alignment marks provided in the internal region of the electrode terminal group, the accuracy of the positioning can be improved as compared with the case where the alignment marks are provided outside the electrode terminal group.

Further, since the liquid crystal side alignment mark and the wiring side alignment mark are provided in the internal area of the liquid crystal side electrode terminal group and the internal area of the wiring side electrode terminal group, respectively, The arrangement position of the terminal group is not restricted, so that the place where each electrode terminal group is arranged can be freely selected.

According to the liquid crystal display device of the present invention, the alignment mark can be easily formed in a narrow place as compared with a case where the alignment mark is formed independently of the electrode terminal.

According to the liquid crystal display device of the third aspect, since the alignment marks are formed by notching the electrode terminals, the alignment marks can be freely formed regardless of the size of the interval between the electrode terminals. .

According to the liquid crystal display device of the fourth aspect, 1
By arranging a plurality of alignment marks in one camera field of view, the positional relationship between the light-transmitting substrate and the wiring element in the tilt direction can be accurately determined by one camera.

According to the liquid crystal display device of the fifth aspect, 1
Since a plurality of alignment marks in one camera field of view are arranged as far apart as possible, high-precision position determination can be performed as long as one camera is used.

According to the liquid crystal display device of the sixth aspect, when forming the alignment marks by deforming the electrode terminals, it is possible to reliably prevent the display characteristics of the liquid crystal display device from being adversely affected.

According to the liquid crystal display device of the present invention, one or both of the main alignment mark provided inside the electrode terminal group and the auxiliary alignment mark provided outside the electrode terminal group are used as required. Since it can be used selectively, it can be applied to various inspection apparatuses such as an inspection apparatus having only one CCD camera and an inspection apparatus having two or more CCD cameras.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is a plan view showing a main part of the liquid crystal display device.

FIG. 3 is a sectional view showing a sectional structure of a main part of the liquid crystal display device of FIG.

FIG. 4 is a perspective view showing one embodiment of a conventional liquid crystal display device.

FIG. 5 is a diagram showing an example of an alignment mark used in a conventional liquid crystal display device.

[Explanation of symbols]

 Reference Signs List 1 liquid crystal panel 2a, 2b transparent substrate (translucent substrate) 3 ACF 4 FPC (wiring element) 6 liquid crystal side electrode terminal group 7 liquid crystal side alignment mark 8 wiring side electrode terminal group 9 wiring side alignment mark 11 CCD camera 16 IC Output electrode terminal 17 Liquid crystal drive IC 18 ACF 21, 22 Auxiliary alignment mark

Claims (8)

[Claims] 1. A pair of light-transmitting substrates facing each other with a liquid crystal interposed therebetween and at least one of them having a liquid crystal side electrode terminal group, and a wiring element having a wiring side electrode terminal group,
In a liquid crystal display device in which the liquid crystal side electrode terminal group and the wiring side electrode terminal group are conductively connected to each other, a liquid crystal side alignment mark provided in an internal region of the liquid crystal side electrode terminal group, and the wiring side electrode terminal group And a wiring-side alignment mark provided in an internal region of the liquid crystal display. 2. The liquid crystal display device according to claim 1, wherein
The liquid crystal side alignment mark and / or the wiring side alignment mark are formed by deforming at least one of a plurality of electrode terminals constituting the liquid crystal side electrode terminal group and / or the wiring side electrode terminal group. Liquid crystal display. 3. The liquid crystal display device according to claim 2, wherein
A liquid crystal display device characterized in that the deformation of the electrode terminal as the liquid crystal side alignment mark and / or the wiring side alignment mark is a notch provided in the electrode terminal. 4. The liquid crystal display device according to claim 1, wherein a plurality of liquid crystal side alignment marks and a plurality of wiring side alignment marks are provided in one camera field of view. Characteristic liquid crystal display device. 5. The liquid crystal display device according to claim 4, wherein
The liquid crystal side alignment mark and the wiring side alignment mark include an alignment mark formed by deforming two electrode terminals located farthest from each other among a plurality of electrode terminals included in one camera field of view. Liquid crystal display device. 6. The liquid crystal display device according to claim 2, wherein the liquid crystal side alignment mark and the wiring side alignment mark are formed by deforming a signal transmission electrode terminal. Display device. 7. The liquid crystal display device according to claim 1, wherein a liquid crystal side auxiliary alignment mark is provided on the light transmitting substrate outside the liquid crystal side electrode terminal group. And a wiring-side auxiliary alignment mark provided on the wiring element outside the wiring-side electrode terminal group. 8. The liquid crystal display device according to claim 1, wherein the wiring element is a flexible wiring substrate having flexibility. apparatus.