JP2007163524A - Method of manufacturing liquid crystal element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a liquid crystal element by which the liquid crystal element is not blotted with a surplus liquid crystal even when a liquid crystal one-drop-filling process with excellent time behavior is used, and by which the liquid crystal element is easily manufactured within a short period of time. <P>SOLUTION: Each rectangular frame-shaped sealing material 2 having notches 3a-3d formed on four corner portions thereof is arranged on each area A of nine sections defined and set on one master electrode substrate 1a, and a liquid crystal 6 is dropped in the inside of each sealing material 2 in slightly excessive quantity. Next, as shown in (b), the other master electrode substrate 1b having trap frames 4a-4d arranged so as to correspond to the notches 3a-3d of the respective sealing materials 2 is positioned and superposed on the master electrode substrate 1a. Subsequently, the gap between both master electrode substrates 1a, 1b is adjusted so as to have a predetermined distance with pressurizing while heating, and simultaneously the sealing materials 2 and the trap frames 4a-4d are subjected to compression drawing so as to close the respective notches 3a-3d and the gaps between the trap frames 4a-4d and the sealing materials 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a liquid crystal element in which liquid crystal is dropped and sealed before bonding a pair of electrode substrates.

  Conventionally, as a method of sealing liquid crystal between a pair of substrates, a pressure difference is utilized from a liquid crystal injection port provided in the sealing material by evacuating a liquid crystal cell obtained by joining the pair of substrates with the sealing material. A vacuum injection method is often used in which liquid crystal is injected and then the injection port is sealed with a sealing material.

  However, the above-described vacuum injection method has a problem that it takes a lot of time to use the pressure difference and the liquid crystal material is easily contaminated or dust is easily mixed because the liquid crystal injection port is immersed in the liquid crystal material. Have.

  In view of this, a dripping method disclosed in Patent Document 1 has been proposed as a method that allows liquid crystal to be sealed efficiently in a short time without being contaminated. This dropping method is a method in which a liquid crystal is dropped onto one substrate before bonding the substrates, and the other substrate is bonded to the substrate to seal the liquid crystal between the substrates.

JP-A-6-235925

  In the above-described dropping method, if the amount of liquid crystal to be dropped is insufficient, a cavity is formed in the liquid crystal layer, causing a malfunction. Therefore, a liquid crystal discharge port is provided in the sealing material and the liquid crystal dropping amount is slightly larger than necessary. And excessive liquid crystal overflows from the outlet when the two substrates are pressure bonded. Thereafter, the liquid crystal discharge port is sealed to complete the liquid crystal element.

  However, the excess liquid crystal that overflows adheres to both substrates or enters between the substrates outside the sealing material and the liquid crystal element becomes dirty, so it is necessary to clean these contaminated liquid crystals. It will take time and man-hours.

  An object of the present invention is to provide a method of manufacturing a liquid crystal element that can easily manufacture a liquid crystal element in a short time without contaminating the liquid crystal element with surplus liquid crystal even when a liquid crystal dropping and sealing method with excellent time efficiency is used. It is.

  In the method of manufacturing a liquid crystal element according to the present invention, the first and second electrode substrates on which a plurality of electrodes for forming a pixel are formed are opposed to each other with the electrode formation surfaces facing each other, and a predetermined gap is maintained therebetween. And a liquid crystal element manufacturing method in which liquid crystal is sealed between the first and second electrode substrates surrounded by the sealing material, wherein the liquid crystal is formed on the electrode forming surface of the first electrode substrate. A sealing material having at least one cut for enclosing the sealing material is disposed, and one of the first and second electrode substrates is surrounded by the sealing material so as to correspond to the cut of the sealing material. A capturing frame is provided outside the liquid crystal sealing region for forming a capturing region for capturing excess liquid crystal overflowing from the cut, and a predetermined amount of liquid crystal is placed in the liquid crystal sealing region surrounded by the sealing material. In front of the second electrode substrate. Each electrode forming surface is opposed to the first electrode substrate and superimposed after the sealing material, and then the pressure is applied to adjust the gap between the electrode substrates to a predetermined size, and an excess from the cut of the sealing material. The liquid crystal overflows into the capture region surrounded by the capture frame, and at the same time, the sealing material is compressed and stretched to close the cuts, and the liquid crystal is filled in each closed sealing material and the capture region is surplus. The capture frame sealing material and the capture frame are cured in a state where the liquid crystal is captured.

  According to the method for manufacturing a liquid crystal element of the present invention, since the capture frame that captures the excess liquid crystal that overflows is disposed for each discharge port that causes the excess liquid crystal to overflow, the excess liquid that has overflowed despite using the liquid crystal drop sealing method. The liquid crystal element is not contaminated by the liquid crystal. As a result, the number of manufacturing steps of the liquid crystal element can be remarkably reduced, and the cost reduction of the liquid crystal element can be greatly promoted.

  In the method for manufacturing a liquid crystal element of the present invention, the capture frame is overlapped with the first electrode substrate of the second electrode substrate so as to correspond to the cut line of the sealing material of the first electrode substrate. Sometimes, a method of forming a sealed space in which the sealing material and the capture frame are compressed and stretched by trapping and joining the electrode substrates by placing the electrode substrates at positions that surround the outside of the cut and press-bonding both electrode substrates. Thus, a large amount of air is captured together with surplus liquid crystal when the two electrode substrates are bonded by pressure bonding, and the occurrence of a problem that the captured air bursts and breaks the capture frame is effectively prevented.

  Further, in the method for manufacturing a liquid crystal element of the present invention, the supplemental frame is disposed at a position where a closed frame is formed so as to cover the outside of the cut of the sealing material of the first electrode substrate, and the overlapped frame is overlapped. A method of forming a sealed space for capturing the surplus liquid crystal with the second electrode substrate may be used, and accordingly, the man-hours required for disposing the capturing frame by disposing the capturing frame integrally with the sealing material simultaneously by a printing method or the like. Can be reduced.

  Furthermore, in the method for manufacturing a liquid crystal element of the present invention, it is preferable that the sealing material is arranged in a rectangular frame shape, and cuts are formed in the corners of the four corners, whereby the liquid crystal is evenly distributed in the sealing material. The excess liquid crystal is evenly discharged from each cut, and a uniform liquid crystal layer is obtained over the entire area in the sealing material, and as a result, a good liquid crystal element having no overall operation unevenness is manufactured with less man-hours. Can do.

  In addition, according to the method for manufacturing a liquid crystal element of the present invention, the first and second electrode substrates are both parent electrode substrates having a size capable of collecting a plurality of liquid crystal elements. It is preferable to apply to a method of collecting a large number of liquid crystal elements that are bonded and then separated into individual liquid crystal elements after curing the sealing material and the capture frame of each liquid crystal element. Devices can be easily and collectively manufactured in a shorter time

  FIGS. 1A and 1B are plan views showing a pair of parent electrode substrates before pressure bonding in the method of manufacturing a liquid crystal display element as an embodiment of the present invention, respectively. FIG. 3B is a plan view showing a stage where the liquid crystal dropping step and the substrate are superposed in the pressure bonding process, and FIGS. 3A to 3D are each stages in the thermocompression bonding process of both substrates. FIG. 4 is a partial plan view showing the state of FIG. 4 in an enlarged manner, and FIG. 4 is a plan view showing a state where the thermocompression bonding is completed. 1 to 4, the sealing material 2 and the trap frames 4a to 4d are schematically shown larger than the actual dimensions for convenience of explanation.

  In the manufacturing method of the present embodiment, nine identical liquid crystal display elements are collected from a pair of parent electrode substrates 1a and 1b. Accordingly, as shown in FIGS. 1A and 1B, the parent electrode substrates 1a and 1b having a pair of rectangles have nine sampling areas A having the same area in an arrangement of 3 rows × 3 columns, respectively. Is set. In each collection area A, although not shown, electrodes for driving the liquid crystal are arranged in a predetermined pattern.

  First, as shown in FIG. 1A, a sealing material 2 for sandwiching liquid crystal between substrates is disposed on each electrode forming surface of one parent electrode substrate 1a. In the present embodiment, for each collection area A, the sealing material 2 is arranged in a rectangular frame shape along the periphery of each area. The sealing material 2 uses a thermosetting epoxy resin as a material and is applied to an arrangement shown by screen printing.

  In the corners at the four corners of each rectangular frame-shaped sealing material 2, cuts 3a to 3d for overflowing excess liquid crystal are formed. Each of the cuts 3a to 3d is formed along a diagonal line of the rectangular frame, and the width ws thereof is dimensioned so that each of the cuts 3a to 3d is reliably closed by compressing and stretching the sealing material 2 at the time of the substrate pressure bonding. Is set.

  On the other parent electrode substrate 1b, as shown in FIG. 1B, a trap for collecting liquid crystals overflowing from the cuts 3a to 3d of the sealing material 2 at the four corners of each sampling area A The frames 4a to 4d are respectively arranged. Each of these trap frames 4a to 4d is accurately arranged at a set position where the sealed space can be formed with the corresponding sealing material 2 by being compressed and stretched at the time of the substrate pressure bonding. And these trap frames 4a-4d are made into the frame shape illustrated by screen printing using the composite material which disperse-mixed the spacer particle | grains 41 (refer FIG. 3) in the thermosetting epoxy resin same as the sealing material 2. FIG. Applied. In this case, the average particle diameter of the spacer particles 41 is set to be approximately equal to the substrate interval outside the liquid crystal sealing area surrounded by the sealing material 2. Since various functional film layers such as a color filter and its protective layer are not laminated outside the liquid crystal enclosure area, the substrate interval is larger than the substrate interval in the liquid crystal enclosure area.

  Next, as shown in FIG. 2A, the liquid crystal 6 is dropped into each sealing material 2 of the parent electrode substrate 1a. At this time, the amount of liquid crystal dropped for each sampling area A is surrounded by the parent electrode substrates 1a and 1b to be pressure-bonded with a predetermined gap and the sealing material 2 with the cut lines 3a to 3d closed. An appropriate amount is set to fill the liquid crystal enclosure space.

  The substrate spacing in the liquid crystal sealing area is fixed by dispersing gap material particles (not shown) as a substrate spacing regulating member in the sealing material 2 or evenly dispersing on the substrate in the liquid crystal sealing area. It is kept at a predetermined interval by a known method such as a method of installing or a method of dispersing and mixing in the liquid crystal 6.

  Next, as shown in FIG. 2B, the parent electrode substrate 1b on which the trap frames 4a to 4d are applied to the parent electrode substrate 1a on which the liquid crystal is dropped is positioned with reference to both alignment marks (not shown). Accurately overlap while matching. In this substrate overlapping stage, for example, as shown in FIG. 3A of the partially enlarged view showing the trap frame 4b and the vicinity thereof, the sealing material 2 corresponding to the front end face 42 of each trap frame 4a to 4d, Is spaced apart with the gap 5 maintained.

  When the superposition of the parent electrode substrate 1b on the parent electrode substrate 1a is completed, a thermocompression bonding tool (not shown) is brought into pressure contact with the outer surface (non-electrode forming surface) of the parent electrode substrate 1b, and each sealing material 2 and each trap frame 4a to 4d are pressurized while being heated through the parent electrode substrate 1b. As a result, the sealing material 2 and the trap frames 4a to 4d are softened and started to be compressed and stretched. As shown in FIG. 3B, the gaps 3a to 3d are gradually narrowed and the gap 5 is gradually increased. Becomes smaller. Further, the liquid crystal 6 dropped in parallel with this starts to diffuse substantially evenly in the surrounding four directions.

  Thereafter, by continuing heating and pressurization with the thermocompression bonding tool, as shown in FIG. 3 (c), the liquid crystal 6 diffusing to the periphery passes through the cuts 3a to 3d whose width is becoming narrower, and the sealing material. 2 overflows outside. At this time, the gap 5 between the tip surface 42 of each trap frame 4a to 4d and the corresponding sealing material 2 is small but not closed, so that the air in the trap frames 4a to 4d smoothly passes through the gap 5 to the outside. Discharged. Therefore, the occurrence of a problem that air is trapped in the trap frames 4a to 4d and ruptures to destroy the trap frames 4a to 4d is reliably prevented.

  And if heating and pressurization with a thermocompression bonding tool are further continued until a predetermined time elapses, as shown in FIG. 3 (d), the cuts 3a to 3d are reliably closed, and each of the trap frames 4b The gap 5 between the front end face 42 and the sealing material 2 is also closed. As a result, the liquid crystal 6 fills the closed sealing material 2 without voids, and the excess liquid crystal 6 overflowing to the outside of the sealing material 2 is trapped in the closed space surrounded by the trap frames 4 a to 4 d and the sealing material 2. The desired liquid crystal encapsulated state can be obtained.

  FIG. 4 shows a state in which the above-described thermocompression bonding process of the parent electrode substrates 1a and 1b is completed. At the stage where this thermocompression bonding process is completed, as shown in the drawing, the liquid crystal 6 is filled in the closed sealing material 2 in all the sampling areas A without voids, and the trap frames 4a to 4d are filled. The excess liquid crystal is reliably captured without leaking. Thereby, the malfunction which an excess liquid crystal dissipates and soils parent electrode substrate 1a, 1b is prevented reliably.

  Further, in the manufacturing method in which a plurality of liquid crystal display elements are collectively collected from the parent electrode substrate as in the present embodiment, the liquid crystal is usually not filled between the liquid crystal encapsulating areas and remains a cavity, so that the thermocompression bonding is performed. When the pressure is applied at the time of bonding, the substrate at that portion is likely to be recessed, and this reaction has a problem that the substrate in the sealing material 2 is lifted and gap unevenness that increases the gap of the liquid crystal layer is likely to occur. However, in this embodiment, as described above, each trap frame 4a to 4d contains spacer particles 41 (see FIG. 3) having an average particle size substantially equal to the substrate interval between adjacent liquid crystal enclosure areas. Therefore, the occurrence of the dent between the adjacent liquid crystal sealing areas and the unevenness of the gap of the liquid crystal layer due to the dent is effectively prevented.

  After the thermocompression bonding of the parent electrode substrates 1a and 1b is completed, the parent electrode substrates 1a and 1b are cut along the scribe lines L and separated into individual liquid crystal display elements. Since the liquid crystal display element thus obtained is not contaminated with the excess liquid crystal that has diffused, the number of man-hours required for cleaning it can be saved. In addition, the occurrence of unevenness in the gap of the liquid crystal layer, which causes unevenness in the display of the liquid crystal display element, is effectively prevented.

  As described above, in the method for manufacturing a liquid crystal display element of the present embodiment, the rectangular frame-shaped sealing material 2 is arranged for each of the plurality of liquid crystal display element collection areas A of the parent electrode substrate 1a. In the corners at the four corners, cuts 3a to 3d for overflowing excess liquid crystal are formed so as to be closed when the sealing material 2 is compressed and stretched when the parent electrode substrates are joined together by thermocompression bonding. The trap frames 4a to 4d for capturing the excess liquid crystal overflowing in correspondence with the two cuts 3a to 3d are arranged, and when the thermocompression bonding of the parent electrode substrates 1a and 1b is completed, the cuts 3a to 3d are made. Since each of the trap frames 4a to 4d forms a closed space for capturing the excess liquid crystal overflowing with the corresponding seal material 2, the trap frames 4a to 4d are closed. Frames 4a-4 The trap liquid 4a to 4d is prevented from being damaged by trapping a large amount of air together with the surplus liquid crystal and rupturing the air, and the surplus liquid crystal is reliably trapped in the trap frames 4a to 4d. . As a result, contamination of the parent electrode substrates 1a, 1b, etc. due to the dispersion of excess liquid crystal can be prevented, and it is possible to save the trouble of cleaning the contamination due to excess liquid crystal after being separated into individual liquid crystal display elements. A step of closing the cuts 3a to 3d serving as the discharge ports for the excess liquid crystal after dropping and bonding the parent electrode substrates 1a and 1b by thermocompression bonding becomes unnecessary. The This makes it possible to easily and collectively manufacture a large number of liquid crystal display elements from a large-sized parent electrode substrate in a short time using a liquid crystal dropping and sealing method with excellent time efficiency.

  Further, in this case, the trap frames 4a to 4d are arranged on a parent electrode substrate 1b different from the parent electrode substrate 1a on which the sealing material 2 is arranged, and spacer particles 41 are contained in the material of the trap frames 4a to 4d. Since the average particle size of the particles 41 is made to coincide with the substrate interval in the area where the liquid crystal between the adjacent sealing materials 2 and 2 is not filled, the substrate between the adjacent sealing materials is caused by the pressure when the substrates 1a and 1b are thermocompression bonded. It is possible to effectively prevent the occurrence of indentation and the occurrence of irregularities in the liquid crystal layer thickness due to this.

  Furthermore, since the cuts 3a to 3d are formed along the diagonal lines in the four corners of the rectangular frame-shaped sealing material 2, when the two substrates are bonded by thermocompression bonding, the dropped liquid crystal is uniformly diffused in four directions. It is possible to smoothly overflow from the cuts 3a to 3d. Thereby, it is possible to uniformly fill the liquid crystal without generating a cavity in each sealing material 2.

  Therefore, according to the method for manufacturing a liquid crystal display element of this embodiment, a high-quality liquid crystal display element in which the occurrence of display defects due to variations in the liquid crystal layer thickness such as display unevenness is prevented can be efficiently manufactured in an extremely short time. It becomes possible to do.

In addition, this invention is not limited to said embodiment.
For example, in the above-described embodiment, the trap frames 4a to 4d are arranged on an electrode substrate 1b different from the parent electrode substrate 1a on which the sealing material 2 is arranged. However, the present invention is not limited thereto, and the parent electrode substrate on which the sealing material 2 is arranged. You may arrange | position a trap frame to 1a. In this case, if the trap frame is made of the same material as the sealing material and applied and arranged simultaneously by screen printing or the like, it is difficult to selectively contain spacer particles only in the trap frame. Although the effect of preventing dents is reduced, the manufacturing man-hours for arranging the trap frame separately are shortened, and the trapping space for the excess liquid crystal closed at the time of application and placement can be formed more reliably. In addition, the excess liquid crystal is captured, and alignment when the substrates are overlapped is facilitated, thereby improving workability.

  Further, it is sufficient that at least one cut is formed in the sealing material. Even when the sealing material is arranged in a rectangular frame shape as in the above-described embodiment, one is provided at each of the two corners of the diagonal two corners. Alternatively, it is possible to adopt a configuration in which only one is formed at the optimum position.

  Furthermore, the sealing material is not limited to the one made of a thermosetting resin, and for example, a material based on an ultraviolet irradiation curable resin can be used. In this case, it is necessary to heat the sealing material when crimping the parent electrode substrate. Rather, after the interval between the substrates has been adjusted to a predetermined size, it may be cured by irradiating with ultraviolet rays.

  In addition, the present invention is not limited to a method for manufacturing a liquid crystal display element, and can of course be widely applied to other methods for manufacturing liquid crystal elements such as a liquid crystal shutter.

(A), (b) is the typical top view which respectively showed a pair of parent electrode board | substrates before thermocompression bonding in the manufacturing method of the liquid crystal display element as one Embodiment of this invention. (A), (b) is the typical top view which showed the liquid crystal dropping step in the thermocompression bonding process, and the step which piled up the substrates, respectively. (A)-(d) is the typical partial top view which expanded and showed the state of each step in the thermocompression bonding process of both substrates, respectively. It is the typical top view showing the state where thermocompression bonding was completed.

Explanation of symbols

1a, 1b Parent electrode substrate 2 Sealing material 3a, 3b, 3c, 3d Cut 4a, 4b, 4c, 4d Trap frame 41 Spacer particle 42 Tip surface 5 Gap 6 Liquid crystal

Claims (5)

The first and second electrode substrates on which a plurality of electrodes for constituting a pixel are formed are bonded to each other with a sealant therebetween while keeping respective electrode formation surfaces facing each other, and surrounded by the sealant. A method of manufacturing a liquid crystal element in which liquid crystal is sealed between the first and second electrode substrates,
A sealing material having at least one cut for enclosing liquid crystal is disposed on the electrode forming surface of the first electrode substrate;
One of the first and second electrode substrates is provided on the outer side of the liquid crystal sealing region surrounded by the sealing material so as to correspond to the cut of the sealing material, and excess liquid crystal overflowing from the cut Place a capture frame to form a capture area to capture
A predetermined amount of liquid crystal is dropped into the liquid crystal sealing region surrounded by the sealing material,
The second electrode substrate is pressed after overlapping each electrode formation surface with the first electrode substrate through the sealing material, and the gap between both electrode substrates is adjusted to a predetermined size, and Overflowing excess liquid crystal from the cuts in the seal material into the capture region surrounded by the capture frame, and simultaneously compressing and stretching the seal material to close the cuts,
A manufacturing method of a liquid crystal element, wherein the closed sealing material is filled with liquid crystal, and the capture frame sealing material and the capture frame are cured in a state where excess liquid crystal is captured in the capture region.   The capture frame is disposed at a position surrounding the outside of the cut when overlapped with the first electrode substrate of the second electrode substrate so as to correspond to the cut of the sealing material of the first electrode substrate. The method for manufacturing a liquid crystal element according to claim 1, wherein the sealing material and the capture frame are compressed and stretched by pressure bonding the two electrode substrates to form a sealed space for capturing the excess liquid crystal.   The supplemental frame is disposed at a position to form a closed frame that covers the outside of the cut of the sealing material of the first electrode substrate, and captures the excess liquid crystal with the superimposed second electrode substrate. A method for producing a liquid crystal element according to claim 1, wherein a sealed space is formed.   The said sealing material is arrange | positioned at rectangular frame shape, The said cut | interruption is each formed in the corner of the four corners, The liquid crystal element of any one of the Claims 1 thru | or 3 characterized by the above-mentioned. Production method.   Each of the first and second electrode substrates is a parent electrode substrate having a size capable of collecting a plurality of liquid crystal elements. The parent electrode substrate is bonded by pressure bonding, and a sealing material and a capture frame for each liquid crystal element are provided. The method for manufacturing a liquid crystal element according to claim 1, wherein the liquid crystal element is separated into individual liquid crystal elements after being cured.

Images