JP2002221699A - Method for inspecting and manufacturing liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for accurately inspecting displacement between respective liquid crystal display panels of a laminated type liquid crystal display device with no error. SOLUTION: Respective inspection patterns 24 are displayed in a displaying part 20 of the respective laminated liquid crystal display panels 6. The inspection of the displacement between a plurality of the liquid crystal display panels 6 is carried out based on the patterns 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection method for a multi-layer liquid crystal display device in which a plurality of liquid crystal display panels are stacked. Further, the present invention relates to a method for manufacturing a multilayer liquid crystal display device.

[0002]

2. Description of the Related Art In recent years, it has become possible to manufacture a liquid crystal display panel using a light and thin film substrate made of a resin or the like. .

FIG. 12 is a partial cross-sectional view schematically showing one example of such a liquid crystal display device. As shown in the figure, the display device 2 includes three stacked liquid crystal display panels 6 (a blue display panel 6B and a green display panel 6 in order from the observation side).
G, red display panel 6R).

Each liquid crystal display panel 6 (6B, 6G, 6R)
Is a film-shaped first substrate 9 (9) made of a transparent material.
B, 9G, 9R) and the second substrate 10 (10B, 10G,
10R), a resin structure 12 for bonding and supporting the first substrate 9 and the second substrate 10, and a resin structure 12
The liquid crystal 14 is filled in the gap formed by the above. The liquid crystal 14 is, for example, a chiral nematic liquid crystal that can selectively reflect light having a wavelength in the visible region. Although not shown, a spherical spacer is also included between the first and second substrates 9 and 10. If necessary, a light absorbing layer 15 is provided on the back surface of the second substrate 10R of the red display panel 6R. A plurality of transparent strip-shaped first electrodes 16 (16B, 16G, 16R) are arranged on the upper and lower surfaces of the first substrate 9 in the drawing at predetermined intervals. On the other hand, on the upper surface of the second substrate 10 in the drawing, a plurality of transparent strip-shaped second electrodes 18 (18B, 18G, 18R) are arranged in parallel at predetermined intervals. These first electrode 16 and second electrode 16
The arrangement direction of the electrodes 18 is orthogonal when viewed from a direction perpendicular to the substrate, and the first electrodes 16 and the second electrodes
(Intersection points when viewed from a direction perpendicular to the substrate) form pixels of the display device 2. A set of these pixels is arranged in a matrix, and display is performed by the set of pixels. Specifically, by applying a predetermined voltage to the predetermined first and second electrodes 16 and 18, the first electrode 16 and the second electrode 18 (as viewed from a direction perpendicular to the substrate) are formed. The display is performed by changing the state of the liquid crystal portion located at the intersection.

In the manufacture of such a stacked liquid crystal display device, a plurality of liquid crystal display panels are stacked so as not to be displaced in order to precisely align the respective liquid crystal display panel portions constituting the pixels. This is very important. For this purpose, a mark for alignment is printed in advance on the substrate of each liquid crystal display panel, a plurality of liquid crystal display panels are aligned based on the alignment marks, and these liquid crystal display panels are stacked.

[0006]

After this laminating step, an inspection for positional deviation is performed.
There is a method of observing alignment marks (inspection patterns) used for laminating the liquid crystal display panels. However, since a film substrate is used as a substrate constituting the liquid crystal display panel, the relative position between the display region (the region where display is performed by a set of pixels) and the mark may be shifted due to contraction or bending of the substrate due to heat. An accurate test cannot be performed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an inspection method capable of accurately inspecting the displacement of each liquid crystal display panel of a multi-layer liquid crystal display device without errors.

Another object of the present invention is to provide a method of manufacturing a multilayer liquid crystal display device, which includes a step of easily forming an alignment mark on a liquid crystal display panel.

[0009]

In order to achieve the above object, an inspection method according to the present invention is directed to a method for inspecting a multi-layer liquid crystal display device in which a plurality of liquid crystal display panels are stacked.
The method includes a step of displaying a test pattern in a display section of each liquid crystal display panel, and performing a test of a positional shift of the plurality of liquid crystal display panels based on the pattern.

In one embodiment of the liquid crystal display panel, a first
A first substrate on which a plurality of first electrodes are formed in parallel with the first direction, and a second surface facing the first surface at a predetermined distance, A second substrate on which a plurality of second electrodes are formed on a second surface in parallel with a second direction intersecting the first direction; and between the first substrate and the second substrate. And a liquid crystal layer interposed between the first electrode and the second electrode when viewed from a direction perpendicular to the substrate.

[0011] In the case of the liquid crystal display panel having the above-described configuration, the displacement detection step includes a step of bringing a plurality of first and second probes into contact with the first and second electrodes, respectively; And a probe specifying step of specifying a probe that contacts the second electrode, and a step of applying a predetermined voltage to predetermined first and second electrodes via the specified probe to display an inspection pattern. .

[0012] In one embodiment, the predetermined first and second predetermined values are set.
Are formed on the first and second substrates in advance so that their resistance values are different from those of the other first and second electrodes, respectively. Therefore, it is possible to specify which probe is in contact with the predetermined first and second electrodes by measuring the resistance value. Specifically, the resistance between the contact point of the probe on each of the first and second electrodes and another point may be measured.

In another embodiment, the continuity between the contact point of the probe on each of the first and second electrodes and another point is detected. As a result, which probe is in the given first and second
Can be specified whether or not they are in contact with the electrodes.

In still another embodiment, a first electrode pad electrically connected to a predetermined plurality of first electrodes and a second electrode pad electrically connected to a predetermined plurality of second electrodes are provided. Electrode pads are pre-formed on the first and second substrates, respectively. In this mode, in order to display the inspection pattern,
It is possible to easily apply a predetermined voltage to the predetermined first and second electrodes from the outside via the first and second electrode pads.

[0015] After the positional displacement inspection, a portion for electrically connecting the predetermined first and second electrodes to the first and second electrode pads, respectively, is separated from the first and second substrates. The predetermined first and second electrodes can be used as normal display electrodes.

By using a liquid crystal having a memory property, the display of the inspection pattern can be maintained without continuously applying a voltage from the outside.

In a first aspect of the method of manufacturing a multi-layer liquid crystal display device according to the present invention, a manufacturing process for manufacturing each of the above-described liquid crystal display panels and an alignment mark for displaying an alignment mark on each of the manufactured liquid crystal display panels are provided. A display step, based on the alignment marks displayed in the alignment mark displaying step, aligning the plurality of liquid crystal display panels, and laminating these liquid crystal display panels, the alignment mark displaying step includes:
A plurality of first and second electrodes are respectively provided on the first and second electrodes.
Contacting a predetermined probe, a probe specifying step of specifying a probe that contacts the predetermined first and second electrodes, and applying a predetermined voltage to the predetermined first and second electrodes via the specified probe. And applying.

In a second aspect of the method of manufacturing a multi-layer liquid crystal display device according to the present invention, a manufacturing process for manufacturing each of the above-described liquid crystal display panels and an alignment mark for displaying alignment marks on each of the manufactured liquid crystal display panels are provided. A display step, based on the alignment marks displayed in the alignment mark displaying step, aligning the plurality of liquid crystal display panels, and laminating these liquid crystal display panels, the alignment mark displaying step includes:
Applying a predetermined voltage to predetermined first and second electrodes from outside via the first and second electrode pads.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an inspection method according to the present invention will be described below with reference to the accompanying drawings. In the following description, in order to facilitate understanding of the invention, terms indicating directions (for example, “up,” “down,” “right,” “left,”
And other terms including these) are used as appropriate, but the scope of the present invention is not limited by these terms.

(Configuration of Liquid Crystal Display Panel) FIG.
The top view of each liquid crystal display panel of a multilayer liquid crystal display device is shown. As shown in the figure, the first electrode 1 on the first substrate 9 is bonded to the first substrate 9 and the second substrate 10 in a state where they are bonded to each other.
6 is exposed on the first substrate 9 so that a portion of 6 is exposed to the atmosphere.
1A, electrode terminal regions 22R and 22L are provided on the right and left sides of the display unit 20, respectively. here,
The display unit 20 refers to a portion of each panel 6 that constitutes a display region (consisting of a group of pixels) of the display device in a state where the liquid crystal display panels 6 are attached to each other to produce a multilayer liquid crystal display device.

Similarly, in a state where the first substrate 9 and the second substrate 10 are bonded to each other, the second electrode 18 on the second substrate 10 is exposed so that a part of the second electrode 18 is exposed to the atmosphere. The substrate 10 has electrode terminal regions 23U and 23D provided above and below the display unit 20 with respect to FIG.

The electrode terminal regions 22 and 23 may be provided on only one side of the display unit 20, respectively.

The electrode terminal regions 22 (22L, 22R), 2
3 (23U, 23D) connects a substrate (not shown) on which the drive circuit is mounted in order to apply a predetermined voltage from the drive circuit (not shown) to the first and second electrodes 16, 18. It is provided in order to do. In the present invention, before connecting the substrates, the electrode terminal regions 22 and 23 are formed during the step of laminating the liquid crystal display panel 6 and the step of inspecting the displacement after the lamination of the liquid crystal display panel 6. It is connected to a probe of an inspection device described later, and a predetermined voltage signal is supplied through the probe so that the alignment mark 24
Is displayed. In the figure, the alignment marks 24 are provided in the four corner regions of the display unit 20, respectively. However, if the alignment marks are displayed in at least two diagonal corner regions, the liquid crystal display panel 6 can be laminated based on these alignment marks. Can be. On the other hand, after stacking, by observing the alignment marks 24 displayed in at least two diagonal corner regions of each liquid crystal display panel, it is possible to inspect the positional shift between the liquid crystal display panels 6.

If the vicinity of the outer periphery of the display section 20 of each liquid crystal display panel 6 is accurately aligned, it can be considered that the liquid crystal display panels 6 are accurately aligned over the entire display section 20. It is preferable that the alignment mark is displayed near the outer periphery of the display unit 20 as described above.

In order to display the alignment mark 24, predetermined first and second electrodes 16 and 18 may be used, and an electrode dedicated to the alignment mark needs to be provided separately from the predetermined electrodes 16 and 18. There is no. By providing such an electrode dedicated to alignment, it is possible to prevent a wasteful region from being generated in the liquid crystal display panel, and to narrow the frame.

As the liquid crystal of the liquid crystal display panel 6, a liquid crystal having a memory property (for example, chiral nematic liquid crystal) is used. Once display is performed, a voltage is applied to predetermined electrodes 16, 18 for displaying an alignment mark. , The display state of the alignment mark is maintained. Therefore, lamination of the liquid crystal display panel and the like can be performed in a state where the above-described inspection device probe is removed from the electrode terminal regions 22 and 23.

The shape of the alignment mark is shown in FIG.
2A, a hollow square shown in FIG. 2A, a cross shown in FIG.
Any L-shaped one or a cross-shaped inverted pattern shown in FIG. Further, the alignment mark 26 may be displayed along the outer periphery of the display unit 20 as shown in FIG.

Since different colors are displayed on the respective liquid crystal display panels as described above, it is possible to perform a positional deviation inspection using the alignment marks of the same shape in each liquid crystal display panel. On the other hand, if the shape of the alignment mark is made different in each liquid crystal display panel and the shape of the alignment mark is used for the inspection of the positional deviation, the inspection can be performed more reliably and with higher reliability. FIGS. 3A to 3D show a state in which the alignment marks are made different in each display panel and the three liquid crystal display panels are precisely bonded together when viewed from a direction perpendicular to the substrate. It shows an example of alignment marks 24A, 24B, 24C of each display panel. FIG.
(A) is a combination of a hollow rectangle and a rectangle that fills the hollow rectangle, FIG. 3 (b) is a combination that becomes a cross as a whole, FIG. 3 (c) is a combination that becomes a rectangle as a whole,
FIG. 3D shows a combination that forms a cross-shaped inverted pattern as a whole.

(Description of Manufacturing Process of Display Device) FIG. 4 shows an example of a manufacturing process of a multi-layer liquid crystal display device. First, a plurality of liquid crystal display panels 6 are manufactured (Step A), and alignment marks are displayed on each liquid crystal display panel 6 (Step B).
Next, after aligning each liquid crystal display panel at a predetermined position using an alignment mark (step C), the liquid crystal display panels are stacked (step D). Subsequently, the alignment marks are displayed again (step E), and the positional deviation between the liquid crystal display panels 6 is inspected (step F). Thereafter, a drive circuit and the like are mounted (Step G), and a final inspection of the liquid crystal display device is performed (Step H). Here, in step D, the liquid crystal display panel is attached via an adhesive sheet. The reason why the alignment marks are re-displayed in the step E is that the liquid crystal display panels are bonded together while pressing the liquid crystal display panels in the step D, as described later, so that the liquid crystal in the panel is in its state by the external pressure. Is changed, and the alignment mark displayed in the process B disappears or the display is incomplete. Hereinafter, the steps C, D, and F are referred to as a positioning step, a bonding step, and a displacement inspection step, respectively. In the present embodiment, at least the alignment step, the bonding step, and the positional deviation inspection step are performed using the following automatic apparatus.

(Structure of Automatic Device) FIG. 5 is a schematic view showing an example of an automatic device 30 for bonding two liquid crystal display panels and inspecting a displacement after bonding. The automatic device 30 includes the first and second liquid crystal display panels 6.
There are first and second tables (XYθ tables) 32 and 34 for adsorbing and fixing A and 6B, respectively. These tables 32 and 34 can be moved and rotated in the X-axis and Y-axis directions orthogonal to each other in the same horizontal plane.

The first table 32 uses a transport mechanism (not shown) to hold an inspection position 32a for aligning the first liquid crystal display panel 6A and the like, and the first and second liquid crystal display panels 6A and 6B. It can be moved in parallel between the bonding positions 32b to be bonded. Similarly, the second table 34 uses the transport mechanism (not shown) to set the inspection position 3 for performing alignment with the second liquid crystal display panel 6B.
4a, the panel suction surface faces the panel suction surface of the first table 32, and the first and second liquid crystal display panels 6A, 6B
Can be inverted between the bonding positions 34b where the two are bonded. As shown in the drawing, one end of the second liquid crystal display panel 6B is not held by the suction surface of the second table 34 while being sucked on the second table 34.

In the automatic device 30, the first liquid crystal display panel 6A exactly matches a predetermined reference position at the inspection position 32a, and furthermore, the second liquid crystal display panel 6B
Is set at the inspection position 34a so as to exactly match the predetermined reference position, the first and second tables 3
After the substrates 2 and 34 have been transported to the bonding positions 32b and 34b, respectively, the first and second liquid crystal display panels 6A and 6B can be bonded accurately.

A loader unit (not shown) for mounting the first liquid crystal display panel 6A on the table 32 is provided beside the first table 32 arranged at the inspection position 32a, as will be described later. An unloader (not shown) for removing the first and second liquid crystal display panels 6A and 6B bonded at the bonding position 32b is arranged. In addition, a probe (not shown) of an inspection device for displaying an alignment mark on each side of the first table 32 and the side of the loader unit arranged at the inspection position 32a.
Are disposed so as to be connectable and separable to the electrode terminal area of the liquid crystal display panel.

Similarly, the second position located at the inspection position 34a
Of the second liquid crystal display panel 6B
A loader unit (not shown) for mounting the camera on the table 34 is arranged. A probe (not shown) of an inspection device for displaying an alignment mark is provided on each of the side of the second table 34 and the loader section arranged at the inspection position 34a, on the second liquid crystal display panel 6B. It is arranged to be connectable and separable to the electrode terminal area.

Further, in order to detect the position of the alignment mark displayed on the liquid crystal display panel, the inspection position 32 is detected.
a of the CCD camera 3 above the first table 32 in FIG.
6 are arranged. Similarly, the second liquid crystal display panel 6
In order to detect the position of the alignment mark displayed on B, a CCD camera 38 is arranged above the second table 34 at the inspection position 34a. A CCD camera may be provided so as to be movable, and may be moved above each alignment mark to photograph the mark. Alternatively, a plurality of CCD cameras may be installed at predetermined positions corresponding to the respective alignment marks. . A control device 40 is connected to the CCD cameras 36 and 38. The control device 40
When the positions of the alignment marks, that is, the positions of the first and second liquid crystal display panels 6A and 6B are respectively calculated based on the image signals output from the CD cameras 36 and 38, and the marks are shifted from the reference positions. First and second position discriminating circuits (not shown) for calculating the amount of deviation, and first and second driving circuits for driving the first and second tables 32 based on the detection results of these position discriminating circuits. (Not shown). CCD camera 3
The first and second position discriminating circuits are also used to detect the positions of the respective alignment marks of the first and second liquid crystal display panels 6A and 6B bonded at the bonding position 32b in the position shift inspection process. Is done.

The automatic device 30 also includes a bonding position 32
b, 34b arranged above the first table 32 and near the right side of the second table 34 (the side facing one end of the second liquid crystal front panel 6B not supported by the second table 34). And a pressing roller 42 having an axis parallel to the liquid crystal panel suction surface of the first table 32.

(Description of Operation of Automatic Device) Next, a series of operations of the automatic device 30 (positioning step, bonding step,
And a displacement inspection step. ) Will be described.

First, the probe of the inspection device is brought into contact with the electrode terminal areas of the first and second liquid crystal display panels 6A and 6B arranged in each loader section, and the alignment marks are displayed. After that, the probe is removed from the electrode terminal area, but the alignment mark is kept displayed because the liquid crystal having the memory property is used.

Subsequently, the first and second liquid crystal display panels 6
A and 6B are adsorbed and fixed to the first and second tables 32 and 34, and an adhesive sheet (not shown) is attached to the upper surface of the first liquid crystal display panel 6A. And CCD camera 3
Reference numerals 6 and 38 denote first and second liquid crystal display panels 6, respectively.
The alignment marks A and 6B are photographed, and the image signals are input to the first and second position determination circuits of the control device 40.
The first and second position discriminating circuits respectively correspond to the first and second position discriminating circuits.
Calculate the positions of the alignment marks of the liquid crystal front panels 6A and 6B based on the video signals related to the marks,
If the marks are shifted from the reference position, the shift amount is calculated, and a signal corresponding to the calculation result is sent to the first and second driving units. The first and second driving units respectively control the first and second tables 32,
34 to drive the first and second liquid crystal display panels 6A, 6A.
Set B at the reference position.

After the alignment step, the first and second tables 32 and 34 are transported to the bonding positions 32b and 34b. Therefore, as shown in FIG. 6A, the first table 34 is fixed in a state where the second table 34 is fixed at the bonding position 34b.
By sliding the table 32 in the direction of arrow 44, the pressing roller 42 provided at a predetermined position
The first and second liquid crystal display panels 6A and 6B are overlapped and laminated while sequentially pressing the second liquid crystal display panel 6B against the first liquid crystal display panel 6A. Here, the force for adsorbing the second liquid crystal display panel 6B of the second table 34 is determined by the force for adhering the second liquid crystal display panel 6B via the adhesive sheet provided on the first liquid crystal display panel 6A. The second liquid crystal display panel 6 </ b> B is slid along the suction surface of the second table 34. In the drawing, the first table 32 is bonded while sliding in the direction of arrow 44 toward the detection position 32a. However, the first table 32 moves between the detection position 32a and the bonding position 32b. It is not always necessary to make the moving direction equal to the sliding direction for bonding the panels.

After the bonding step, as shown in FIG. 6B, the first table 32 returns to the inspection position 32a.
Since the panels are bonded to each other while pressing the first and second liquid crystal display panels 6A and 6B, the state of the liquid crystal in the panels changes due to the external pressure, and the alignment marks displayed in the alignment step disappear. The display is incomplete. Therefore, the alignment marks on the first and second liquid crystal display panels 6A and 6B are displayed again by using the detector arranged on the side of the first table 32. Then, using the CCD camera 36 again, it is inspected whether or not there is a positional shift between the alignment marks of the first and second liquid crystal display panels 6A and 6B. The alignment pattern displayed in the displacement inspection step may be the same as the alignment pattern displayed in the alignment step. As will be described later, if an electrode for displaying an alignment pattern is formed in advance so as to have a different resistance or the like from other electrodes, it is possible to easily redisplay the alignment pattern.

Since the bonding accuracy of the automatic device 30 gradually changes due to the wear and aging of the device, even if the first and second liquid crystal display panels 6A and 6B are accurately set at the reference positions, the bonding accuracy can be improved. After the alignment, the first and second liquid crystal display panels 6A and 6B may be misaligned. Therefore, the number of defective products can be minimized and the yield can be improved by feeding back the positional deviation inspection result to the panel alignment process. For example, in the case where a fixed positional shift is repeatedly generated between the first and second liquid crystal display panels 6A and 6B bonded to each other, the first and / or second liquid crystal is adjusted so as to cancel the positional shift. The display panels 6A and 6B are set while being shifted from the reference position.

In the present embodiment, the same CCD camera 36 and first position discriminating circuit are used in the alignment step and the displacement inspection step, so that the automatic device 30 can be simplified and the cost can be reduced.

Further, since the automatic device 30 has two liquid crystal display panels bonded together, when three or more liquid crystal display panels are stacked, the two liquid crystal display panels are bonded together and then these display panels are bonded together. After the misalignment inspection is performed, it is preferable to further bond the third and subsequent liquid crystal display panels. However, in the case where the bonding accuracy is relatively high, the positional displacement inspection may be performed after all the liquid crystal display panels are bonded.

Note that an automatic device having a mechanism for simultaneously bonding three or more liquid crystal display panels may be used.

(Method of Displaying Alignment Mark) In order to display the alignment mark on the display section of the liquid crystal display panel, it is necessary to apply a predetermined voltage to a specific electrode. However, in a high-resolution display device in which the pitch of the electrodes is narrow, it is difficult to accurately contact the tester probe with the electrodes on the electrode terminal area.
Therefore, it is desired to display a desired alignment mark without strictly aligning the electrode and the probe. Hereinafter, an embodiment of a method for easily realizing this problem will be described.

Embodiment 1 FIG. 7 is an enlarged partial top view showing the periphery of an alignment mark displayed on each liquid crystal display panel of a multi-layer liquid crystal display device. In the figure, the electrodes in the display unit,
And the electrode part drawn out to the electrode terminal area is shown in a see-through state. Reference numeral 50 denotes a seal wall provided between the first substrate 9 and the second substrate 10 so as to surround the display unit for enclosing the liquid crystal.

FIG. 8 is a schematic perspective view showing an example of the inspection device. The tester 52 has a plurality of probes 54 arranged at the same pitch as the electrodes and a conductive member 56, and an ammeter 58 arranged between the probes 54 and the conductive member 56 for continuity therebetween. It can be checked using.

When displaying the alignment mark,
First, the probe 54 is brought into contact with the first electrode 16 on the electrode terminal region 22 of the first substrate 9 and all the electrodes 16
If the conductive member 56 is placed so as to cause a short circuit, the continuity between each probe 54 and the conductive member 56 can be checked, and any of the probes is located at the extreme end (the uppermost position in FIG. 7). It can be seen whether the electrode 16 is in contact. Similarly, the probe 54 is brought into contact with the second electrode 18 on the electrode terminal region 23 of the second substrate 10 and all the electrodes 1
If the conductive members 56 are placed so as to short-circuit 8, the continuity between each probe 54 and the conductive member 56 can be checked, and any of the probes is located at the extreme end (the leftmost in FIG. 7). Is in contact with the electrode 18.

Note that depending on the positional relationship between the first and second electrodes 16 and 18 and the probe 54, the contact between them may be insufficient as shown in FIG. 9A. In such a case, all the electrodes can be brought into contact with each probe 54 as shown in FIG.

As described above, if it is known which probe 54 the electrodes 16 and 18 are in contact with,
By detaching the conductive member 56 in a state where the conductive member 56 is in contact with the first and second electrodes 16 and 18, by applying a voltage to the predetermined first and second electrodes 16 and 18 via the probe 54,
A desired alignment mark 60 can be displayed.

As shown in the figure, a needle 54 is used as the probe 54 of the inspection device 52, and the probe is brought into contact with the electrode along a direction substantially perpendicular to the direction in which the electrode extends, thereby bonding the first bonded substrate. And each of the liquid crystal display panels 6A, 6B in order to inspect the displacement of the second liquid crystal display panels 6A, 6B.
It is preferable that the electrode terminal regions of B are formed in a step shape so as not to overlap with each other.

Embodiment 2 In the liquid crystal display panel 6a shown in FIG. 10 (a), the specific first electrode 16a and the specific second electrode 18a have the resistance values of the other first and second electrodes, respectively. Electrodes 16a, 1
It is formed in advance so as to be different from 8a (for example, to have high resistance). In the example of the figure, as best shown in FIG. 10 (b), the width of the electrode between the electrode portion contacting the probe 54 and the electrode portion contacting the conductive member 16 in each of the electrode terminal regions 22a and 23a. And a high-resistance region 62 is provided. By checking the current value between each probe 54 and the conductive member 56, it is possible to determine which probe is in contact with the high-resistance electrodes 16a and 18a.

When it is known which probe 54 the specific first and second electrodes 16a, 18a having high resistance are in contact with, the specific electrode 16a, 1
The desired alignment mark 64 can be displayed by detaching the conductive member 56 in a state of being in contact with 8a and applying a voltage to the specific electrodes 16a and 18a via the probe 54. Since a voltage is applied to the electrode via the probe 54, it is more preferable to dispose the probe 54 inside the high-resistance region 62 and the conductive member 56 outside the high-resistance region 62 when displaying the alignment mark 64. Adjustment of the applied voltage is easy.

The substrate portion including the high-resistance region 62 is preferably cut off after the positional deviation inspection so as not to adversely affect the display (the cut-off line is, for example, shown in FIG. 10).
In FIG. ). After the cut-off process, a substrate on which a drive circuit is mounted is connected to the electrode terminal regions 22a and 23a.

Embodiment 3 In the liquid crystal display panel 6b shown in FIG. 11, a specific plurality of first electrodes 16b and a specific plurality of second electrodes 18b
Are extended outside the other first and second electrodes 16b and 18b, respectively, and are electrically connected to the first and second electrode pads 70 and 72, respectively.
Specific electrodes 16b, 18b are provided through the pads 70, 72.
A desired common alignment mark 74 is displayed by applying a predetermined common voltage. These electrode pads 70, 72 have a larger surface area than the first and second electrodes 16b, 18b on the electrode terminal regions 22b, 23b, so that a voltage application probe (not shown) can be easily padded. 70, 72 can be contacted. As a result, a voltage can be applied to the target electrode without precise positioning of the probe.

The first and second electrode pads 70 and 72 are
First and second electrodes 16 for displaying alignment marks
By cutting off the connection portion with the b and 18b after the positional displacement inspection (the cut-off line is, for example, a reference numeral 7 in FIG. 11).
6 and 78. ), Can be separated from these electrodes 16b, 18b. As a result, the electrodes 16b and 18b separated from the electrode pads 70 and 72 can be used as normal display electrodes. After the cutting-off process, the substrate on which the drive circuit is mounted is connected to the electrode terminal regions 22b and 23b.

By the way, unlike the above-described embodiment, when manufacturing a curved liquid crystal display device in which liquid crystal display panels formed in a curved shape are laminated, each liquid crystal display panel is close to each other near the edge of the liquid crystal display panel. It is inevitable that the position shift occurs. Therefore, it is preferable to perform the alignment with the highest accuracy at the center of the display section of the liquid crystal display panel (ie, to display the alignment mark at the center of the display section). In some cases, it may be difficult to bring each probe of the tester into contact with the non-flat electrode terminal area. However, if pads are provided as shown in the third embodiment, a target alignment mark can be displayed accurately. it can.

[0059]

According to the displacement inspection method of the present invention, an inspection pattern (alignment mark) is displayed in the display section of each liquid crystal display panel using an electrode.
There is no need to provide a special inspection pattern outside the display unit, so that the manufacturing cost can be reduced and the frame can be reduced accordingly. In addition, since the inspection pattern is displayed by using the display unit of each liquid crystal display panel, it is possible to perform a precise positional deviation inspection with few errors.

Further, according to the method of manufacturing a multi-layer liquid crystal display device according to the present invention, a desired alignment mark can be displayed without strictly aligning an electrode of the liquid crystal display device with an external probe.

[Brief description of the drawings]

FIG. 1A is a top view showing each liquid crystal display panel in which an alignment mark is displayed on a display unit. (B) The top view which shows each liquid crystal display panel which displayed another alignment mark on the display part.

FIG. 2 is a diagram showing an example of another shape of an alignment mark.

FIG. 3 is a diagram showing an example in which the shape of an alignment mark is different for each liquid crystal display panel.

FIG. 4 is a block diagram showing an example of a manufacturing process of the multi-layer liquid crystal display device.

FIG. 5 is a side view showing an example of an automatic device for performing a positioning step, a bonding step, and a position shift inspection step.

FIG. 6A is a side view of an automatic device in a bonding step. (B) A side view of the automatic device in the position shift inspection process.

FIG. 7 is an enlarged partial top view showing the periphery of an alignment mark displayed on each liquid crystal display panel.

FIG. 8 is a schematic perspective view showing an example of an inspection device.

FIG. 9 is a schematic diagram showing a positional relationship between an electrode extended on an electrode terminal area of a liquid crystal display panel and a probe of an inspection device.

FIG. 10A shows an alignment mark display electrode;
FIG. 8 is a view similar to FIG. 7, formed so that the resistance value in the electrode terminal region is different from other electrodes. (B) Partial enlarged view of an alignment mark display electrode in an electrode terminal area.

FIG. 11 shows a plurality of alignment mark display electrodes;
FIG. 8 is a view similar to FIG. 7, in which a voltage application probe is short-circuited to an electrode pad for contacting the probe.

FIG. 12 is an enlarged partial cross-sectional view illustrating an example of a multi-layer liquid crystal display device.

[Explanation of symbols]

2: stacked liquid crystal display device, 6: liquid crystal display panel, 9: first substrate, 10: second substrate, 14: liquid crystal, 16: first
, 18: second electrode, 22: electrode terminal area of first electrode, 23: electrode terminal area of second electrode, 24: alignment mark, 26: alignment mark, 30: automatic device, 32: second electrode 1 table, 34: second table, 36: CCD camera, 38: CCD camera, 52:
Inspector, 54: probe, 56: conductive member, 62: high resistance region, 70: first electrode pad, 72: second electrode pad.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09F 9/46 G09F 9/46 A (72) Inventor Masakazu Okada 2-chome Azuchicho, Chuo-ku, Osaka-shi, Osaka No. 3-13 Osaka International Building Minolta Co., Ltd. F term (reference) 2H088 FA01 FA11 FA16 GA02 GA17 HA02 MA20 2H089 HA22 HA23 HA31 HA32 QA12 QA16 TA02 2H092 MA57 NA27 NA29 NA30 5C094 AA08 AA43 AA48 BA09 BA49 CA19 CA24 DB02 DA03 DA EA05 EB02 FA01 FA02 GB10 5G435 AA04 AA17 BB12 CC09 CC12 KK05 KK10

Claims (21)

[Claims] 1. A method for inspecting a multi-layer liquid crystal display device comprising a plurality of liquid crystal display panels laminated, wherein an inspection pattern is displayed in a display section of each liquid crystal display panel, and a plurality of liquid crystal display panels are displayed based on the patterns. An inspection method characterized by including a displacement inspection step of inspecting a displacement. 2. A liquid crystal display panel comprising: a first substrate having a plurality of first electrodes formed on a first surface in parallel with a first direction; and a predetermined distance from the first surface. A second substrate having a second surface facing away and having a plurality of second electrodes formed on the second surface in parallel with a second direction intersecting the first direction; A liquid crystal layer sandwiched between a first substrate and a second substrate, wherein a state of a liquid crystal portion located at an intersection of the first electrode and the second electrode when viewed from a direction perpendicular to the substrate; 2. The inspection method according to claim 1, wherein the display is performed by changing. 3. The method according to claim 2, wherein the step of inspecting the displacement includes a plurality of first and second electrodes on the first and second electrodes, respectively.
Contacting a predetermined probe, a probe specifying step of specifying a probe that contacts the predetermined first and second electrodes, and applying a predetermined voltage to the predetermined first and second electrodes via the specified probe. A step of applying and displaying an inspection pattern. 4. The method according to claim 1, wherein the predetermined first and second electrodes are formed in advance on first and second substrates such that their resistance values are different from those of the other first and second electrodes, respectively. 4. The method according to claim 3, further comprising a measuring step of measuring the resistance value in the probe specifying step. 5. In the measuring step, each of the first and second
The method according to claim 4, wherein the resistance between the contact point of the probe and another point on the electrode is measured. 6. The method according to claim 3, wherein said probe specifying step includes a step of detecting conduction between a contact point of the probe on each of the first and second electrodes and another point. Method. 7. A first electrode pad electrically connected to a predetermined plurality of first electrodes and a second electrode pad electrically connected to the predetermined plurality of second electrodes, respectively. First
And the position shift inspection step is performed in advance by applying a predetermined voltage to predetermined first and second electrodes from the outside via the first and second electrode pads. A step of displaying a pattern.
Inspection method. 8. After the positional displacement inspection step, a portion for electrically connecting the predetermined first and second electrodes to the first and second electrode pads is separated from the first and second substrates. The inspection method according to claim 7, wherein the separation is performed. 9. The inspection method according to claim 1, wherein an inspection pattern of a different color is displayed for each liquid crystal display panel in the displacement inspection step. 10. The inspection method according to claim 1, wherein an inspection pattern having a different shape is displayed for each liquid crystal display panel in the displacement inspection step. 11. The inspection method according to claim 1, wherein the inspection pattern is displayed near an outer periphery of a display unit of each liquid crystal display panel. 12. The inspection method according to claim 1, wherein each liquid crystal display panel has a liquid crystal having a memory property. 13. A method of manufacturing a multi-layer liquid crystal display device in which a plurality of liquid crystal display panels are stacked, a manufacturing step of manufacturing each of the liquid crystal display panels, and displaying alignment marks on each of the manufactured liquid crystal display panels. An alignment mark display step, based on the alignment mark displayed in the alignment mark display step, aligning a plurality of liquid crystal display panels, and laminating these liquid crystal display panels, the liquid crystal display panel includes: A first substrate on which a plurality of first electrodes are formed in parallel with the first direction on a first surface; and a second surface facing the first surface at a predetermined interval. A second substrate having a plurality of second electrodes formed on the second surface in parallel with a second direction intersecting with the first direction; a first substrate and a second substrate; Sandwiched between A liquid crystal layer provided at the intersection of the first electrode and the second electrode when viewed from a direction perpendicular to the substrate, and performs display by changing a state of the liquid crystal portion. A plurality of first and second electrodes on the first and second electrodes, respectively;
Contacting a predetermined probe, a probe specifying step of specifying a probe that contacts the predetermined first and second electrodes, and applying a predetermined voltage to the predetermined first and second electrodes via the specified probe. And applying. 14. The first and second predetermined electrodes are formed in advance on first and second substrates such that their resistance values are different from those of the other first and second electrodes, respectively. The method according to claim 13, further comprising a measuring step of measuring the resistance value in the probe specifying step. 15. The method according to claim 14, wherein in the measuring step, a resistance between a contact point of the probe on each of the first and second electrodes and another point is measured. 16. The method according to claim 1, wherein the probe identifying step includes a step of detecting conduction between a contact point of the probe on each of the first and second electrodes and another point.
4. The manufacturing method of 4. 17. A method for manufacturing a multi-layer liquid crystal display device in which a plurality of liquid crystal display panels are stacked, a manufacturing step of manufacturing each of the liquid crystal display panels, and displaying an alignment mark on each of the manufactured liquid crystal display panels. An alignment mark display step, based on the alignment mark displayed in the alignment mark display step, aligning the plurality of liquid crystal display panels, and laminating these liquid crystal display panels, the liquid crystal display panel includes: A first substrate on which a plurality of first electrodes are formed in parallel with the first direction on a first surface, and a second surface facing the first surface at a predetermined interval A second substrate having a plurality of second electrodes formed on the second surface in parallel with a second direction intersecting with the first direction; a first substrate and a second substrate; Sandwiched between A liquid crystal layer positioned at an intersection of the first electrode and the second electrode when viewed from a direction perpendicular to the substrate, and performing display by changing a state of the liquid crystal portion. A first electrode pad electrically connected to the first electrode and a second electrode pad electrically connected to a predetermined plurality of second electrodes are formed on the first and second substrates, respectively. The alignment mark display step, which is formed in advance, includes a step of externally applying a predetermined voltage to predetermined first and second electrodes via the first and second electrode pads. Manufacturing method. 18. The method according to claim 13, wherein the alignment mark is displayed near an outer periphery of a display section of each liquid crystal display panel. 19. A method for manufacturing a multi-layer liquid crystal display device in which a plurality of liquid crystal display panels are stacked, a manufacturing step of manufacturing each of the liquid crystal display panels, and displaying an alignment mark on each of the manufactured liquid crystal display panels. An alignment mark displaying step; a laminating step of aligning a plurality of liquid crystal display panels based on the alignment marks displayed in the alignment mark displaying step, and laminating these liquid crystal display panels; Including an inspection pattern to display an inspection pattern, based on the inspection pattern, a positional deviation inspection step of inspecting the positional deviation of the plurality of liquid crystal display panels, the alignment of the liquid crystal display panel in the lamination step,
An imaging device for imaging the display unit of the liquid crystal display panel in the inspection of the misalignment of the liquid crystal display panel in the misalignment inspection step; A manufacturing method characterized by using a position discriminating circuit for detecting a position of a panel in common. 20. The method according to claim 19, wherein the inspection pattern is the same as the alignment mark. 21. The manufacturing method according to claim 19, wherein the positioning of the liquid crystal display panel in the laminating step is controlled based on a result of the inspection in the position shift inspecting step.