JPH04198914A - Production of liquid crystal panel - Google Patents

Abstract

PURPOSE:To easily and efficiently produce the liquid crystal panels by moving the long-sized liquid crystal panel in the longitudinal direction of the panel relative to a lightening inspection device and subjecting the panel to a lighting inspection while impressing a voltage between the electrodes of two sheets of flexible substrates with the electrodes, then cutting the panel, thereby obtaining the liquid crystal panels subjected to the lighting inspection. CONSTITUTION:The long-sized liquid crystal panel formed by crimping a liquid crystal material 11 subjected to an orientation treatment between two sheets of the flexible substrates 1 with the electrodes is moved in the longitudinal direction of the panel relative to the lighting inspection device and is subjected to the lighting inspection while the voltage is impressed between the electrodes of two sheets of the flexible substrates 1 with the electrodes. The long-sized liquid crystal panel is thereafter cut to the individual liquid crystal panels. The liquid crystal panels subjected to the lighting inspection are thus obtd. The liquid crystal panels subjected to the lighting inspection are easily and efficiently obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a liquid crystal panel used for liquid crystal display elements, electronic elements, etc.

[Prior Art] Conventionally, as a method of manufacturing a liquid crystal panel using long flexible substrates, (1) a pair of long substrates on which a plurality of display pattern electrodes are formed are bonded one after another, and a gap is placed between the substrates. A method of sealing liquid crystal and closing a long liquid crystal panel, cutting and dividing the long liquid crystal panel into individual liquid crystal panels, and then applying a voltage between the electrodes of the liquid crystal panel to perform a lighting test. 2
) In the same way as above, liquid crystal is applied or dropped on one or both of the long substrates on which a plurality of display pattern electrodes are formed, and both are successively bonded together to encapsulate the liquid crystal, and then cut and divided into individual liquid crystal panels. , a method for performing a lighting inspection.

However, these methods have the following problems because each liquid crystal panel is inspected after cutting and dividing each liquid crystal panel.

(1) In order to conduct a continuity test after cutting a long liquid crystal panel, a means for transporting each liquid crystal panel to an inspection apparatus, a means for installing it, and a means for taking it out are required, making the apparatus for manufacturing the liquid crystal panel complicated.

(2) In a liquid crystal panel displaying a dot pattern, it is difficult to align each dot with an inspection jig.

(3) When a long liquid crystal panel is mechanically cut to a certain size, as shown in Figure 5 (a), if the long liquid crystal panel has defective parts such as conduction defects or missing electrode patterns, it will be defective. Depending on the location of the parts, there is a possibility that a usable liquid crystal panel cannot be obtained, and the yield of liquid crystal panels is poor.

In addition, as a method for testing multiple liquid crystal panels at once, the lighting test is performed by sandwiching the liquid crystal between substrates that have lead-out electrodes that are electrically connected to display pattern electrodes, and then cutting the liquid crystal panels into side panels. A method has been proposed (Japanese Unexamined Patent Publication No. 2-222925). However, even with this method, when applying voltage during lighting inspection, it is only necessary to align the extraction electrode and the terminal for applying voltage, and since a glass substrate is used, it is impossible to increase the length and serial production. There's a problem with Kotona.

[Invention or Problem to be Solved] The present invention is capable of testing the lighting of a liquid crystal panel online without cutting a long liquid crystal panel, and it is possible to easily and efficiently manufacture a liquid crystal panel that has been tested for lighting. The aim is to provide a method for manufacturing liquid crystal panels that can

[Means for Solving the Problems] As a result of intensive research to solve the above-mentioned problems, the present inventors conducted a lighting test on a long liquid crystal panel, and then cut it into individual liquid crystal panels and completed the lighting test. The inventors have discovered that the object can be achieved by a method for manufacturing a liquid crystal panel, and have completed the present invention based on this knowledge.

That is, in the present invention, an elongated liquid crystal panel formed by sandwiching an aligned liquid crystal material between two flexible substrates with electrodes is moved in the longitudinal direction of the panel with respect to a lighting inspection device. A liquid crystal panel characterized in that a lighting test is performed while applying a voltage between the electrodes of a flexible substrate with electrodes, and then a long liquid crystal panel is cut into individual liquid crystal panels to obtain a liquid crystal panel that has been tested for lighting. A manufacturing method is provided.

The elongated liquid crystal panel used in the present invention is formed by sandwiching an aligned liquid crystal material between two flexible substrates with electrodes.

The flexible substrate with electrodes is a flexible substrate with electrodes disposed on one side.

The flexible substrate is not particularly limited as long as it is a flexible and transparent material. For example, plastic films such as polyethylene terephthalate (CPET), polyether sulfone (PES), and polycarbonate (PC) can be used. The thickness of the board is usually 1
It is preferably 0 μm to several mm.

The electrode disposed on one side of the flexible substrate is not particularly limited as long as it is made of a transparent material.

For example, a transparent electrode such as an ITO film made of indium oxide or a mixture of indium oxide and tin oxide is suitable,
Usually these are deposited on the flexible substrates mentioned above. Also,
The shape of the electrode is preferably patterned by etching or the like to match the desired display.

There is no particular restriction on the liquid crystal material to be sandwiched between the flexible substrates with electrodes. Ferroelectric liquid crystal materials are preferred from the viewpoint of film formability and responsiveness to changes in electric field. In particular, a liquid crystal material made of a ferroelectric polymer liquid crystal or a composition thereof is preferable. Furthermore, the liquid crystal material used in the present invention may contain an adhesive, a thinning agent, a non-liquid crystal chiral compound, a dye, etc., as necessary.

It is preferable that the liquid crystal material is subjected to alignment treatment when it is sandwiched between the electrode-equipped flexible substrates or thereafter, so that its liquid crystal molecules are uniaxially horizontally aligned. There are no particular restrictions on the orientation treatment method, such as the conventionally well-known rubbing method,
An oblique evaporation method, a magnetic field application method, a temperature gradient method, etc. can be used. When using a polymer liquid crystal composition as a liquid crystal material, after sandwiching the liquid crystal material between flexible substrates with electrodes,
Heating the flexible substrate and applying shear between the upper and lower flexible substrates at a temperature lower than the phase transition point between the isotropic phase and the liquid crystal phase of the liquid crystal material to align the liquid crystal material and align the liquid crystal molecules. The method (described in JP-A-2-10322) is suitable.

The shape of a long liquid crystal panel is 0.3m or more in length and 0.3m or more in width. 1 to 1 m, with a length to width ratio of 3 to 50
Preferably, it is 0.

There are no particular limitations on the method of manufacturing such a long liquid crystal panel. For example, using two long flexible electrode-attached substrates, a liquid crystal material is applied to the electrode-side surface of one of the electrode-attached flexible substrates, and then the other electrode-attached flexible substrate is coated on the formed liquid crystal layer. A preferred method is to sandwich the flexible substrates by stacking them on top of each other with the electrode side facing inside.

The method of applying the liquid crystal material is to increase fluidity by dissolving the liquid crystal material in a solvent or heating it, and then to apply it using a microgravure method, tie left gravure method, etc.
A suitable method is to coat the electrode-side surface of a flexible substrate with electrodes to a uniform thickness. An impregnating coating method is also suitable, in which an impregnated member is impregnated with a liquid crystal material having increased fluidity, and the impregnated member is pressed against the electrode-side surface of a flexible substrate with electrodes and applied while being moved.

When the other flexible substrate is superimposed on the formed liquid crystal layer, it is preferable to superpose it so that the liquid crystal layer and the surface on the electrode side are in contact with each other. It is preferable to stack the upper and lower substrates so that no air bubbles enter between the stacked substrates and the liquid crystal layer, and to sandwich the liquid crystal layer between the upper and lower substrates with a uniform thickness. At this time, it is preferable to heat the flexible substrates to be stacked. In addition, in order to facilitate the connection between the respective extraction electrodes and the electrode terminals of the power supply, it is preferable that the two flexible substrates with electrodes be shifted in the width direction so that the extraction electrodes do not overlap with each other. .

In the present invention, first, a lighting test is performed while moving the above-mentioned long liquid crystal panel in the longitudinal direction of the panel with respect to a lighting testing device while applying a voltage between the electrodes of two electrode-attached flexible substrates.

Since the lighting test is performed while moving the long liquid crystal panel with respect to the lighting test device, in the present invention, the lighting test is not performed for each individual liquid crystal panel, but is performed continuously for the long liquid crystal panel. I can do it.

There is no particular restriction on the moving speed of the long liquid crystal panel with respect to the lighting inspection device. If the moving speed of this long liquid crystal panel is the same as the moving speed of the long liquid crystal panel in the above-mentioned long liquid crystal panel manufacturing process such as the liquid crystal material coating process, the stacking process, the alignment process, etc. The lighting inspection process can also be performed continuously with these processes, which is preferable because productivity of the liquid crystal panel is improved.

The lighting test is performed while applying a voltage between the electrodes of two electrode-attached flexible substrates.

In order to facilitate the application of a voltage between the electrodes of two flexible substrates with electrodes, it is preferable to use a flexible substrate with an extraction electrode at one end as the electrode of the flexible substrate with electrodes.

FIGS. 1(a) and 1(b) are explanatory diagrams showing examples of electrode shapes suitable for manufacturing a dot matrix display panel.

As shown in FIG. 1(a), the electrodes of one of the two flexible substrates with electrodes are connected to the flexible substrate 1.
It shall consist of a plurality of display pattern electrodes 2 of a predetermined length parallel to the longitudinal direction, a connection electrode 3 that electrically connects these display pattern electrodes 2, and an extraction electrode 4 that is electrically connected to the connection electrode 3. , the electrodes of the other flexible substrate with electrodes are connected to a plurality of display pattern electrodes 2 parallel to the width direction of the flexible substrate 1 and electrically connected to these display pattern electrodes 2, as shown in FIG. 1(b). It is preferable that the lead electrodes 4 are connected to each other. In this case, drawer@
The length of the pole 4 may correspond to the length of the display pattern electrode 2 in the longitudinal direction. Here, in FIG. 1(a), the connection electrode is for applying a voltage to the display pattern electrode during a lighting test.

FIG. 3 is a partial explanatory diagram showing a state in which a voltage is applied between electrodes of a long liquid crystal panel.

While moving the long liquid crystal panel 5 in the longitudinal direction of the panel, the electrode terminals 7 of the voltage application device 6 are brought into contact with the lead-out electrodes 4 of the two electrode-attached flexible substrates to apply a voltage between the electrodes of the liquid crystal panel. Apply.

At this time, it is preferable to use a blank electrode or the like as the electrode terminal 7 of the voltage application bag M6 in a fixed manner so that a voltage can be directly applied between the electrodes of the elongated liquid crystal panel 5 being moved.

In this way, a lighting test is performed while applying a voltage between the electrodes of the two electrode-attached flexible substrates.

FIG. 4 is a cross-sectional explanatory diagram illustrating lighting inspection.

While applying a voltage between the electrodes of the long liquid crystal panel by bringing the electrode terminal 7 of the voltage application device 6 into contact with the extraction electrode 4 as described above, the long liquid crystal panel is inserted between two polarizing plates 8.
pass between. It is preferable that the polarizing plates 8 are arranged in orthogonal Nicols.

A light source 9 and a sensor 10 are arranged on the outside of the two polarizing plates 8, respectively, and the light emitted from the light source 9 is detected by the sensor 10 after passing through the polarizing plate 8, the liquid crystal panel, and the polarizing plate 8.

As the sensor 10, one for visible light or one for infrared light can be used. Further, a monitor camera may be provided instead of the sensor 10 or at the same time.

In such a lighting test, the display pattern is monitored using a sensor or a monitor camera, and defects such as conduction defects in the long liquid crystal panel or defects in the display pattern electrodes are detected.

Thereafter, the long liquid crystal panel is cut into individual liquid crystal panels to obtain a lighting-tested liquid crystal panel.

When cutting a long LCD panel into individual LCD panels of a certain size, it is easy to determine whether the resulting LCD panels are good or defective because they have already been tested for lighting. I can do something.

During or after this cutting, the connection electrodes and extraction electrodes are cut off, and if necessary, the periphery of the liquid crystal panel is sealed to complete the liquid crystal panel.

Normally, it is preferable to attach polarizing plates to both sides of a long liquid crystal panel after the lighting test and before cutting.

In the above method for manufacturing a liquid crystal panel, the electrodes of one of the two flexible substrates with electrodes are connected to the second flexible substrate with electrodes.
As shown in Figure (a), a display pattern electrode 2 consisting of a plurality of electrode groups formed seamlessly in the longitudinal direction of a flexible substrate 1, a connection electrode 3 that electrically connects these display pattern electrodes 2, and If the extraction electrode 4 is electrically connected to the connection electrode 3, there is no need to align the two flexible substrates with electrodes, improving productivity. It is possible to cut into individual liquid crystal panels while removing defective parts such as conduction defects, which is preferable because it improves the yield of liquid crystal panels. Here, the connection electrode is provided to prevent a voltage drop in the display pattern electrode during a lighting test. Such connection electrodes are selected from the following two points: (2) to apply sufficient voltage to the display pattern electrodes for lighting inspection, and (2) to need to be cut off before making the final product.
It is preferable to provide them at intervals of 3 to 3 m. As shown in FIG. 2(b), the electrodes of the other main electrode-attached flexible substrate include a plurality of display pattern electrodes 2 parallel to the width direction of the flexible substrate 10 and electrical connections to these display pattern electrodes 2. The flexible substrate 1 may be formed of an extraction electrode 4 that is connected to the flexible substrate 1 and is formed seamlessly in the longitudinal direction of the flexible substrate 1.

When cutting a long LCD panel into individual LCD panels, a sensor detects and marks the location of the defective part through a lighting inspection, and the long LCD panel is cut into individual LCD panels by removing the marked part from the LCD panel. It is preferable to cut it into a liquid crystal panel. It is preferable that such determination of the cutting position be performed automatically under computer control.

FIGS. 5(a) and (b) are explanatory diagrams showing the cutting positions of a long liquid crystal panel into individual liquid crystal panels when using the electrodes shown in FIGS. 2(a) and (b). be.

When a long liquid crystal panel 5 having a defective part 12 such as a conduction defect is mechanically cut at a cutting position 13 of a certain size, as shown in FIG. There is a possibility that a usable liquid crystal panel will not be obtained, resulting in poor yield. However, when the location of defective parts such as continuity defects is detected by lighting inspection, as shown in Fig. 5(b),
The cutting position 13 is cut so as to remove the defective part 12 such as a conduction defect.
It is preferable to cut the liquid crystal panel 14 by cutting the liquid crystal panel 14.

All of the above liquid crystal panel manufacturing processes can be performed online, and the productivity of liquid crystal panels can be significantly improved.

FIG. 6 is an explanatory diagram showing an example of a process flow when all manufacturing processes of a liquid crystal panel are performed online.

This example includes a coating step 16 in which a liquid crystal material is applied onto the electrodes of a flexible substrate 15 with electrodes unrolled from a roll, a superposition step 17 in which the flexible substrate 15 with electrodes is overlapped with the other rolled flexible substrate 15; An alignment treatment step 18 in which the liquid crystal material is aligned to form a long liquid crystal panel 5, a lighting inspection step 19 in which defective parts are detected and marked, and a polarization step in which polarizing plates 20 are pasted on both sides of this long liquid crystal panel 5. Pasting the board is step 21
and cut the long liquid crystal panel 5 into individual liquid crystal panels 2.
It consists of a cutting step 22 of 3. 24 indicates a roll.

In the cutting process 22, the inspection process 19 is carried out under computer control.
Decide the cutting position so as to exclude the marked part and perform the cutting.

[Examples] The present invention will be explained in detail based on Examples below, but the present invention is not limited thereto.

Example 1 A PES (polyether sulfone) having a thickness of approximately 100 μm, a width of 150 mm, and a length of 20 m was used as a transparent flexible substrate. One side of the PES board is shown in Figure 1 (a).
As shown in , a transparent conductive film (approximately 200 angstroms thick) patterned with 80 display pattern electrodes with a width of 1.6 mm (interelectrode gap 0.1 mm), connection electrodes and extraction electrodes provided at intervals of 350 mm. IT of
O electrode) is attached.

A ferroelectric liquid crystal having the structure and characteristics shown below was used as the liquid crystal material.

Mn #3000 (gniglass state, SmC": chiral smectic C phase, SmA: smectic A phase, Iso: isotropic phase) The above liquid crystal material was dissolved in toluene (concentration 25% by weight), and this solution was attached to the rTO electrode. A film was formed by coating on an ITO electrode on a flexible substrate using a microgravure coater.The coating speed was 2.0 m/min.The following steps were also performed at the same speed.Film of liquid crystal material after solvent evaporation Thickness is 22μm
Met.

Next, as shown in FIG. 1(b), the width is 1.6 mm in the direction orthogonal to the longitudinal direction of the substrate over the entire length of the substrate.

A display pattern electrode with an inter-electrode gap of 0.1 mm and an ITO electrode with patterned extraction electrodes PES substrates similar to those described above were stacked so as to be in contact with either the ITO electrode or the liquid crystal material. Here, the two flexible substrates with TO electrodes were stacked so that their respective extraction electrodes did not overlap but came out from the ends.

The obtained long stacked liquid crystal material is subjected to an alignment treatment by bending deformation using an alignment device consisting of three heatable alignment rolls 25 as shown in FIG. It was set as panel 5. Here, each temperature of the orientation roll is T,
=86°CXT2=T3=60°C.

Thereafter, a lighting test was performed while moving the obtained long liquid crystal panel in the longitudinal direction of the panel so that the polarization axis was parallel to each polarizing plate between two mutually orthogonal polarizing plates. That is, as shown in Fig. 3, the electrode terminals from the voltage application device are connected to the extraction electrodes protruding from both ends of the two ITO@ flexible substrates with electrodes, and +100 is applied to the electrodes of the liquid crystal panel. As shown in Figure 4, while applying a voltage of -10■, the light emitted from the light source installed at the bottom of the panel changes the lighting pattern of the liquid crystal panel, conduction defects, non-lighting due to disconnection of the IT○ electrode, etc. The defective part was monitored with a camera installed at the top. In addition, defective parts were marked based on detection with an infrared sensor. Here, since the electrode terminals for voltage application were fixed and the long liquid crystal panel was moved at any time, it was possible to perform the lighting test continuously.

Polarizing plates were pasted on both sides of the long liquid crystal panel that had been tested for lighting, and the cutting position was determined using computer block control to remove the markings.
The liquid crystal panel was cut into individual liquid crystal panels so as to obtain a 200-dot liquid crystal panel to obtain a liquid crystal panel that had been tested for lighting. Furthermore, the lead electrodes and connection electrodes of the liquid crystal panel were cut off, and the four sides of the liquid crystal panel were sealed with epoxy adhesive to complete the liquid crystal panel.

Example 2 Two flexible substrates similar to those in Example 1 were each coated with the material shown in Fig. 2 (
A liquid crystal panel was manufactured in the same manner as in Example 1, except that the patterned electrodes shown in a) and (b) were used as two flexible substrates with electrodes. Here, the second
As shown in Figure (March), in order to prevent a voltage drop during the lighting test, connection electrodes were provided with a spacing of 1.4 m.This made it possible to perform the lighting test continuously.

Comparative Example 1 A liquid crystal panel was manufactured in the same manner as in Example 1 except that the lighting test was not performed.
After cutting at regular intervals so as to obtain a single liquid crystal panel with 0 dots, it was inspected for the presence or absence of defective parts such as conduction defects.

Comparative Example 2 A liquid crystal panel was manufactured in the same manner as in Example 2 except that the lighting test was not performed.
After cutting at regular intervals so as to obtain a single liquid crystal panel with 0 dots, it was inspected for the presence or absence of defective parts such as conduction defects.

As described above, in Example 1.2 and Comparative Example 1.2, the number of usable liquid crystal panels obtained from a 20 m long substrate, the yield, and the time required for lighting inspection of one panel (Comparative Example 1
Table 1 shows the values normalized by setting the case of 1 to 1.

Table 1 [Effects of the Invention] According to the method for manufacturing a liquid crystal panel of the present invention, it is possible to inspect a liquid crystal panel continuously online without cutting a long liquid crystal panel, and the liquid crystal display can be easily and efficiently inspected. Can you manufacture panels?

In particular, when using a long substrate with an electrode pattern continuously formed in the longitudinal direction of the flexible substrate, manufacturing yield can be improved by cutting the long liquid crystal panel into individual liquid crystal panels by removing defective parts. can be improved.

[Brief explanation of the drawing]

Figure 1 (a) and (b) and Figure 2 (a) and (b)
FIG. 2 is an explanatory diagram showing an example of an electrode shape suitable for manufacturing a dot matrix display panel. FIG. 3 is a partial explanatory diagram showing a state in which a voltage is applied between electrodes of a long liquid crystal panel. FIG. 4 is a cross-sectional explanatory diagram illustrating lighting inspection. FIGS. 5(a) and 5(b) are explanatory diagrams showing the positions at which a long liquid crystal panel is cut into individual liquid crystal panels. FIG. 6 is an explanatory diagram showing an example of a process flow when all manufacturing processes of a liquid crystal panel are performed online. FIG. 7 is an explanatory diagram showing the alignment processing apparatus used in Example 1. Explanation of symbols 1 Flexible substrate 2 Display pattern electrode 3 Connection electrode 4 Extraction electrode 5 Long liquid crystal panel 6 Voltage application device 7 Electrode terminal 8 Polarizing plate 9 Light source 10 Sensor 11 Liquid crystal material 12 Defective part 13 Cutting position 14 Usable Liquid crystal panel 15 Flexible substrate with electrodes 16 Coating process 17 Overlapping process 18 Alignment process 19 Lighting inspection process 20 Polarizing plate 21 Polarizing plate pasting is a process

Claims (1)

[Claims] While moving a long liquid crystal panel formed by sandwiching an aligned liquid crystal material between one or two flexible substrates with electrodes relative to a lighting inspection device in the longitudinal direction of the panel, A lighting test is performed while applying a voltage between the electrodes of two flexible substrates with electrodes.
A method for manufacturing a liquid crystal panel, comprising: thereafter cutting the long liquid crystal panel into individual liquid crystal panels to obtain a liquid crystal panel that has been inspected for lighting. 2. A display pattern electrode consisting of a plurality of electrode groups in which the electrodes of at least one of the two flexible substrates with electrodes are formed continuously in the longitudinal direction of the flexible substrate;
2. The method of manufacturing a liquid crystal panel according to claim 1, comprising a connection electrode for electrically connecting these display pattern electrodes and a lead-out electrode electrically connected to the connection electrode. 3. A lighting-inspected liquid crystal panel is obtained by detecting and marking the position of the defective part with a sensor during the lighting test, and cutting the long liquid crystal panel into individual liquid crystal panels so as to remove the marked part from the liquid crystal panel. 2. The method for manufacturing a liquid crystal panel according to 1 or 2.