JP2007156103A - Liquid crystal sealing device of liquid crystal display element and liquid crystal sealing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal sealing device for substrates stuck to each other, which suppresses the variance in amount of permeation of a sealant to eliminate excessive permeation or non-permeation and allows display of high quality. <P>SOLUTION: In the liquid crystal sealing device for liquid crystal display elements, for sealing with a sealant 20 a liquid crystal injection port of the liquid crystal display element including a sealing part which seals an outer circumference formed by a semiconductor substrate 4 and a transparent substrate 6 with an adhesive and has the liquid crystal injection port 12 for injecting liquid crystal, and the liquid crystal filling the inner part of the sealing part, the liquid crystal sealing device includes a measuring means 26 for measuring a gap width, a detection part 28B for detecting a difference between a preset gap width and the measured gap width, an adjustment means 24 for pressing or sucking the semiconductor substrate or the like to adjust the gap width so that the difference may be zero, a gap control part 30 for optimizing a penetration speed of the sealant, a penetration position detection means 32 for detecting a penetration position, a hardening means 34 for hardening the sealant, and a hardening control part 36 for operating the hardening means on the basis of the detected penetration position. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal sealing apparatus and a liquid crystal sealing method used when sealing a liquid crystal display element, which is a key part of a projector, a projection TV, or the like, after the liquid crystal is injected into a bonded substrate formed during the manufacturing process. It is.

  In recent years, liquid crystal display elements made by bonding a silicon IC (wafer) substrate and a glass substrate and injecting liquid crystal into the gap have been increasingly applied to projectors, projection TVs, etc., and the production volume has been increasing. Yes.

  In order to manufacture this liquid crystal display element, first, pixel electrodes are arranged in a matrix on the surface, and a first substrate made of, for example, a silicon substrate on which a drive circuit corresponding to each pixel electrode is formed, and the surface is transparent. A second substrate made of a transparent glass substrate on which a common electrode is formed is overlaid so that the electrodes face each other. At this time, an adhesive that also serves as a spacer is applied in advance along the peripheral portions of both substrates, and a liquid crystal injection port for injecting liquid crystal is formed by providing a portion where no adhesive is applied. deep. The two substrates are bonded to each other with the adhesive through a predetermined gap, thereby forming a bonded substrate that becomes a liquid crystal display element. Next, the liquid crystal is sufficiently injected from the liquid crystal injection port into the bonding substrate to be the liquid crystal display element, that is, into the gap formed between the two substrates, and then the liquid crystal injection port is completely filled with resin or the like. By sealing the liquid crystal, the liquid crystal is sealed and the liquid crystal display element is completed.

  Here, as described above, the structure of a liquid crystal display element formed using a bonded substrate will be described. FIG. 5 is a schematic sectional view showing a liquid crystal display element formed by injecting liquid crystal into a bonded substrate, and FIG. 6 is a schematic plan view of the liquid crystal display element. As shown in the figure, a bonding substrate 2 to be the liquid crystal display element includes a first substrate 4 made of a semiconductor substrate such as a silicon substrate, and a transparent substrate such as a transparent glass substrate disposed opposite to the first substrate 4. And a second substrate 6 made of the same. Here, the first substrate 4 is formed slightly larger than the second substrate 6. Pixel electrodes (not shown) are arranged in a matrix on the surface of the first substrate 4, and each pixel electrode is provided with a drive circuit. A transparent common electrode (not shown) is formed on the surface of the second substrate 4. The two substrates 4 and 6 are joined together by an adhesive 8 having a spacer function interposed along the periphery thereof, and a gap 10 having a predetermined width is formed therebetween.

  The adhesive 8 is not interposed in a part of the periphery of the substrates 4 and 6, and a sealing portion 13 having a liquid crystal injection port 12 for injecting liquid crystal into the gap 10 is formed here. Has been. Here, in order to facilitate understanding, the shape of the liquid crystal injection port 12 is merely a shape that does not allow the adhesive 8 to partially adhere thereto. However, the shape is not limited to this, and a certain flow path length is provided. It may be formed as a liquid crystal injection port.

In this way, the bonded substrate body 2 is formed. In this case, since the pixel electrode is arranged in a region surrounded by the adhesive 8, this region becomes the display region 14.
Then, a liquid crystal display element is formed by injecting liquid crystal 16 into the gap 10 from the liquid crystal injection port 12 and sealing the liquid crystal injection port 12 of the bonded substrate 2 in a sealed state with a sealing agent 20. It will be.

Here, various methods for sealing by injecting liquid crystal into the bonded substrate have been proposed (Patent Documents 1, 2, etc.), and an example thereof is performed as follows.
First, the bonded substrate is stored in a cassette, and this cassette is placed in a vacuum chamber. Next, the inside of the vacuum chamber is evacuated, and the liquid crystal inlet formed on one end side of the bonded base is brought into contact with the liquid crystal filled in the liquid crystal dish. Next, the inside of the vacuum chamber is returned to the atmospheric pressure, whereby liquid crystal is injected into the gap of the bonded substrate due to the pressure difference between the inside and the outside of the bonded substrate. The excess liquid crystal in the vicinity of the liquid crystal injection port of the bonded substrate after the liquid crystal injection is completed is wiped off, and a sealant is applied to the liquid crystal injection port by a dispenser. The applied sealant penetrates into the liquid crystal injection port by capillary action. If the sealant penetrates into the liquid crystal injection port to some extent, the liquid crystal injection port is completely closed by solidifying the sealant by ultraviolet irradiation or heating. Thereby, the liquid crystal display element is completed.

In the sealing step, in order to reliably seal the liquid crystal injection port, it is necessary to allow the sealant to penetrate into the bonded substrate body to the extent that it does not reach the display area where a large number of pixel electrodes are arranged. Since this sealant gradually permeates into the bonded substrate, after the sealant is applied to the liquid crystal injection port, it is left as it is for a certain standing time. Then, it is determined that the penetration of the sealing agent is completed when a predetermined standing time has elapsed, and the liquid crystal injection port is irradiated with ultraviolet light or heated to cure the sealing agent. It will be blocked (sealed) by the sealant.
Here, each of the bonded substrates has a solid difference, and there is a difference (gap difference) in the gap width (gap width) H1 for each bonded substrate in a state where no pressure is applied. Generally, there is variation.

  Therefore, in the conventional sealing process, for example, the bonded substrate is sandwiched by a sandwiching pressure device to adjust the gap width to an optimum value, or one substrate of the bonded substrate is sucked at a constant pressure by a suction device. In other words, the penetration of the sealant was promoted.

JP 2000-35588 A JP 2003-43504 A

By the way, the above-mentioned bonded substrate has a large variation in the force for sucking the sealing agent held by each bonded substrate due to the gap difference. For this reason, when the bonded substrate is removed from the sandwiching pressure device and the pressure is released, the force for sucking the individual sealant of the bonded substrate varies greatly due to the gap difference before gap adjustment. have. For this reason, in the case of a method in which a sealing agent is applied to the liquid crystal injection port and allowed to permeate into the bonded substrate and left for a certain period of time, if the gap difference is large, the entraining force of the sealing agent is natural. As a result, the permeation rate is increased, resulting in an excessive permeation state.
In addition, when the gap difference is small, the pulling force is weak, so that the penetration rate of the sealant is slowed, and the non-penetration state tends to occur. In such a state, inconveniences such as image defects, water contamination, or liquid crystal outflow may occur.

Further, when the bonded substrate is sucked at a constant pressure with a suction device to promote the penetration of the sealing agent, the liquid crystal injection port varies in size and the suction force of the bonded substrate as described above. May cause the penetration rate of the sealing agent to become extremely fast.In this case, the sealing agent cracks from the weakest part of the central part of the liquid crystal inlet, and air or foreign matter etc. enters the liquid crystal from the cracks. There has been a problem that the display quality deteriorates due to being mixed in.
The present invention has been devised to pay attention to the above problems and to effectively solve them. An object of the present invention is to provide a liquid crystal sealing device for a liquid crystal display element and a liquid crystal sealing method thereof that can suppress high permeation and non-permeation by suppressing variation in the amount of permeation of the sealant and eliminate high permeation. There is.

  According to a first aspect of the present invention, there is provided a sealing portion having a liquid crystal injection port for sealing a periphery formed by a semiconductor substrate and a transparent substrate with a predetermined gap width with an adhesive and injecting liquid crystal, and the liquid crystal injection port A liquid crystal sealing device for a liquid crystal display element that seals the liquid crystal injection port of a liquid crystal display element having a liquid crystal injected from the liquid crystal and filling the sealing portion with a sealant, and measuring means for measuring the gap width A detection unit that detects a difference between the gap width measured by the measurement unit with respect to a preset gap width, and the semiconductor substrate and the transparent substrate so that the difference detected by the detection unit is zero An adjusting means for adjusting the gap width by pressing or suctioning the gap, and a gap control for optimizing the permeation speed at which the sealing agent penetrates into the liquid crystal inlet by controlling the pressing force or suction force by the adjusting means. A penetration position detecting means for detecting a penetration position of the sealing agent that has penetrated into the liquid crystal injection port, a curing means for curing the sealing agent, and operating the curing means based on the detected penetration position. A liquid crystal sealing device for a liquid crystal display element.

  According to a second aspect of the present invention, there is provided a sealing portion having a liquid crystal injection port for injecting liquid crystal and sealing an outer periphery formed by a semiconductor substrate and a transparent substrate with a predetermined gap width with an adhesive. A liquid crystal sealing method for a liquid crystal display element, in which the liquid crystal injection port of a liquid crystal display element having a liquid crystal injected from and filled in the sealing portion is sealed with a sealant, wherein the gap width is measured A measuring step, a detecting step for detecting a difference between the gap width measured in the gap width measuring step with respect to a preset gap width, and an applying step for applying the uncured sealant to the liquid crystal inlet And adjusting the gap width by pressing or sucking the semiconductor substrate and the transparent substrate so that the difference detected in the detection step becomes zero and penetrating the sealing agent into the liquid crystal injection port. An adjustment step, and a curing step of detecting the penetration position through which the sealing agent has permeated and curing the sealing agent when the penetration position reaches a predetermined position. It is a liquid crystal sealing method of a liquid crystal display element.

  In the present invention, the gap width of the bonded substrate body (liquid crystal display element) immediately after liquid crystal injection and before the application of the sealing agent is measured, and the amount of gap difference is used as the basic data to attract the penetration promotion of the sealing agent. For example, by linearly controlling the force so that the force is weak for a large gap difference and strong for a small gap difference, the variation in the penetration rate of the sealant is reduced, and the sealant is stably injected into the liquid crystal inlet. Infiltrate. In addition, the amount of penetration of the sealant is directly recognized by, for example, a CCD camera, and the penetration position is detected using image processing, and this is fed back to confirm the optimum position, and then the sealant is irradiated with ultraviolet rays. Alternatively, it is cured by heating. As a result, the penetration position of the sealant can be stabilized to eliminate excessive penetration or non-penetration.

  According to the liquid crystal sealing device of the liquid crystal display element and the liquid crystal sealing method according to the present invention, it is possible to suppress the permeation amount of the sealant to eliminate excessive penetration and non-penetration, and to perform high quality display. A laminated substrate can be obtained.

Hereinafter, an embodiment of a liquid crystal sealing device and a liquid crystal sealing method for a liquid crystal display element according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a block diagram showing a liquid crystal sealing device for a liquid crystal display element according to the present invention, and FIG. 2 is a cross-sectional view showing a state in which a gap width of a bonded substrate is being measured.

  As shown in FIG. 1, the liquid crystal sealing device 22 for the liquid crystal display element selectively applies or applies a pressing force and a suction force to the bonded substrate 2 to be the liquid crystal display element to form a gap 10. (See FIG. 5), a gap adjusting unit 24 which is an adjusting means for adjusting the gap width H1, a gap measuring unit 26 which is a measuring means for measuring the gap width H1, and a pressing to be applied to the bonded substrate 2. A pressure / suction force calculating unit 28 for determining pressure and suction force, a gap control unit 30 for controlling the gap adjusting unit 24 to operate with the determined pressing force and suction force, and a sealant 20 (FIG. 6). The permeation position detection unit 32 that detects the permeation position of the reference), the curing unit 34 that cures the sealing agent 20, and the operation of the curing unit 34. And a reduction control section 36. Here, the pressing / sucking force calculation unit 28 includes a detection unit 28 </ b> B that detects a difference between a preset gap width and a gap width measurement value measured by the gap measurement unit 26. The operation of the entire apparatus is controlled by a main control unit 38 made of, for example, a microcomputer.

  Specifically, first, the gap adjusting unit 24 includes a frame-type support base 39 for supporting the peripheral portion of the bonded substrate 2 and one substrate of the bonded substrate 20, for example, the lower substrate in the illustrated example. The suction mechanism 40 mainly sucks the first substrate 4 on the side and pulls it downward, and the pressing mechanism 42 presses the second substrate 6 which is the other surface. The suction mechanism 40 can be moved up and down, and sucks the first substrate 4 by, for example, vacuum suction, and can apply a downward force with an arbitrary suction force as necessary.

The pressing mechanism 42 can also be moved up and down, so that the second substrate 6 can be given a downward force with an arbitrary pressing force as required.
The gap measuring unit 26 is constituted by an optical film thickness measuring device having, for example, a quartz fiber, and can be retracted in the vertical direction and the horizontal direction. This optical film thickness measuring device irradiates light of a specific wavelength from the tip of a fiber toward the gap, and measures the generated interference fringes to calculate the width of the gap. The gap measuring unit 26 can measure the gap width H1 when the liquid crystal 16 is injected into the gap 10 of the bonded substrate 2 and when the gap adjusting unit 24 is not operating, when no load is applied. . The measured gap width value obtained at this time is output to the pressing / suction force calculation unit 28. The gap control unit 30 determines the pressing force and / or suction force to be set based on the gap width measurement value.

  The gap width H1 of the bonded substrate 2 is adjusted to be an optimum value as described above, but the difference between the optimum value of the gap width (gap width optimum value) and the gap width H1 at the time of no load, That is, the force for sucking the individual sealing agent 20 of the bonded substrate 2 varies greatly depending on the size of the gap difference (difference in swelling). Therefore, here, the pressing / sucking force calculation unit 28 stores a graph as shown in FIG. 3 showing the relationship between the gap difference, the pressing force, and the suction force, or a relational expression that defines this graph, for example, a ROM. The storage medium 44 is provided. The graphs and relational expressions are obtained in advance by empirical rules such as experiments. Of course, a predetermined optimum gap width is also stored in the storage medium 44.

Referring to FIG. 3, as described above, when the sealing agent 20 is applied to the liquid crystal injection port 12 and penetrated, when the gap difference is large, the pulling force of the sealing agent 20 is increased and the penetration rate is increased. As the gap becomes larger, the pressing force is increased as the gap difference increases. That is, in this case, it acts to suppress the permeation rate.
On the other hand, when the gap difference is small, the pulling force of the sealant 20 is weakened and the permeation rate is slowed to become an unpermeated state. Therefore, in order to prevent this, the suction force is reduced as the gap difference is smaller. Enlarge. That is, in this case, it acts to promote (increase) the penetration rate. In FIG. 3, the suction pressure (osmotic pressure) of the sealant 20 is set to be linear.

The graph shown in FIG. 3 is merely an example, and in order to facilitate understanding, the relationship between the pressing force and the suction force is not applied at the same time. It is preferable that the pressure does not become zero and that a minimum preliminary pressing force (preload) is applied, and that the suction force is not zero and the minimum preliminary suction force is applied.
The gap control unit 30 controls the operation of the gap adjustment unit 24 based on the pressing force and / or suction force determined by the pressing / suction force calculation unit 28.

  The permeation position detection unit 32 includes, for example, a CCD camera 32A that can be retracted and an image processing unit 32B that processes an image obtained by the CCD camera 32A, and projects and seals the portion of the liquid crystal injection port 12. The penetration position 20A of the stopper 20 (see FIG. 6), that is, the boundary position between the liquid crystal 16 and the sealant 20 can be detected. In this case, in order to easily determine the boundary position between the liquid crystal 16 and the sealing agent 20, an illuminating illumination light 48 having a polarizing plate 46 is provided, and a polarizing plate 50 is also provided in the CCD camera 32A. It has been.

The curing control unit 36 operates the curing unit 34 to cure the sealant 20 when the penetration position detected by the image processing unit 32B reaches a predetermined penetration position.
The curing unit 34 cures the sealant 20. Here, for example, an ultraviolet curable resin is used as the sealant 20, and therefore an ultraviolet lamp is used as the cure unit 34. When a thermosetting resin is used as the sealant 20, a heater or an infrared lamp can be used as the curing unit 34.

  A dispenser 52 that can be retracted is provided in the vicinity of the gap adjusting unit 24 so that the sealant 20 can be applied as needed. The pressing / suction force calculating unit 28, the gap control unit 30, the image processing unit 32B, and the curing control unit 36 operate in a microcomputer, for example.

Next, an example of a liquid crystal sealing method performed using the liquid crystal sealing device configured as described above will be described with reference to FIG.
FIG. 4 is a flowchart showing each step of the liquid crystal sealing method according to the present invention. In this method of the present invention, the penetration rate of the sealant is stabilized and the penetration position is also stabilized.
First, if the liquid crystal 16 is injected into the gap 10 of the bonded substrate 2 in a vacuum chamber (S1), the bonded substrate 2 into which the liquid crystal 16 has been injected is supported by the gap adjusting unit 24 of the sealing device 22. Place on the base 39. And the gap width H1 of the bonding base | substrate 12 of an unloaded state is measured using the gap measurement part 26, and a gap width measured value is calculated | required (S2). The state at this time is shown in FIG.

Next, the pressing / suction force calculating unit 28 first obtains a gap difference (= gap width measured value−gap width optimum value) based on the gap width measured value and a predetermined gap width optimum value (S3). ).
Next, based on the gap difference, the pressing force and / or suction force to be applied to the bonded substrate 2 is obtained from the graph shown in FIG. 3 (S4). That is, if the gap difference is large, the pressing force is increased, and if the gap difference is small, the suction force is increased. As described above, it is possible to set at least the preliminary pressing force and / or the preliminary suction force without setting the minimum pressing force and the minimum suction force to “zero”.

  Next, the gap adjusting unit 24 is driven so that the bonded base 2 is sandwiched between the suction mechanism 40 and the pressing mechanism 42 and pressed so that the gap width H1 of the bonded base 2 becomes the optimum gap width. (S5). At this time, the liquid crystal pushed or remaining outside the liquid crystal injection port 12 is wiped off.

Next, the dispenser 52 is driven and the sealing agent 20 is dropped and applied toward the liquid crystal injection port (see FIG. 6) of the bonded substrate 2 (S6).
At this time, the gap adjusting unit 24 is operated according to a command from the gap control unit 30 to drive the pressing mechanism 42 and the suction mechanism 40, and the bonded base 2 is pressed with the previously set pressing force. A force is applied by pushing the upper second substrate 6 or sucking the lower first substrate 4 with the previously set suction force (S7). As described above, by continuously applying the above-described force, the applied sealing agent 20 gradually penetrates into the liquid crystal injection port 12 at an optimum penetration rate. The gap difference is finally set to zero.

  At this time, the image in the vicinity of the liquid crystal inlet 12 is taken into the CCD camera 32A of the penetration position detection unit 32, and the penetration position is always detected by the image processing unit 32B (S8). The detected penetration position, that is, the detected position is sent to the curing control unit 36, and it is determined whether or not the detected position has reached a preset penetration position. The above operation is performed until the detection position reaches a preset infiltration position (NO in S9).

  If the detection position reaches a preset penetration position (YES in S9), the curing control unit 36 operates the curing unit 34 to irradiate ultraviolet rays therefrom, and seals made of ultraviolet curable resin. The stopper 20 is solidified (S10). Then, when the sealing agent 20 is solidified, the gap adjusting unit 24 is operated in the releasing direction to release the pressing force and / or the suction force (S11). Processing will be terminated.

As described above, when the sealing agent 20 is permeated into the liquid crystal injection port 12, the optimum pressing force and / or suction force is applied to the bonded substrate 2, so that the penetration rate of the sealing agent 20 is optimized. can do. That is, the permeation rate can be suppressed or accelerated according to the gap difference between the bonded substrates 2.
Accordingly, it is possible to prevent the penetration rate from being excessively high and prevent excessive penetration, and it is possible to prevent the sealant 20 itself from being cracked due to the excessive penetration rate. Furthermore, since the permeation rate is not too low, it is possible to prevent the non-permeation state from occurring.

In addition, since the sealant 20 is solidified at the optimum penetration position by managing the penetration position of the sealant 20, the excessive penetration or non-penetration of the sealant 20 is prevented from this point. be able to.
Therefore, there is little variation in the amount of penetration of the sealant 20, and a stable and high-quality product can be produced.

It is a block block diagram which shows the liquid crystal sealing device of the liquid crystal display element which concerns on this invention. It is sectional drawing which shows the state which is measuring the gap width of a bonding base | substrate. It is a graph showing the relationship between a gap difference, pressing force, and suction force. It is a flowchart which shows each process of the sealing method which concerns on this invention. It is a schematic sectional drawing which shows the liquid crystal display element formed by inject | pouring a liquid crystal into a bonding base | substrate. It is a schematic plan view which shows a liquid crystal display element.

Explanation of symbols

2 ... Bonded substrate (liquid crystal display element), 2 ... First substrate (semiconductor substrate), 6 ... Second substrate (transparent substrate), 8 ... Adhesive, 10 ... Gap, 12 ... Liquid crystal injection port, 13 ... Sealing unit, 16 ... liquid crystal, 20 ... sealing agent, 22 ... sealing device, 24 ... gap adjusting unit, 26 ... gap measuring unit, 28 ... pressing / suction force calculating unit, 28B ... detecting unit, 30 ... gap control 32, penetrating position detection unit, 32A, CCD camera, 32B, image processing unit, 34 ... curing unit, 36 ... curing control unit, 39 ... support base, 40 ... suction mechanism, 42 ... pressing mechanism.

Claims (2)

A sealing part having a liquid crystal injection port for sealing the outer periphery formed by the semiconductor substrate and the transparent substrate with a predetermined gap width with an adhesive and injecting liquid crystal; and the inside of the sealing part injected from the liquid crystal injection port A liquid crystal sealing device for a liquid crystal display element that seals the liquid crystal injection port of a liquid crystal display element having a liquid crystal to be filled with a sealing agent,
Measuring means for measuring the gap width;
A detection unit that detects a difference between the gap width measured by the measurement unit with respect to a preset gap width;
Adjusting means for adjusting the gap width by pressing or sucking the semiconductor substrate and the transparent substrate so that the difference detected by the detection unit becomes zero;
A gap control unit that controls a pressing force or a suction force by the adjusting means to optimize a penetration speed at which the sealant penetrates into the liquid crystal injection port;
A permeation position detection means for detecting a permeation position of the sealant that has permeated into the liquid crystal injection port;
Curing means for curing the sealant;
A curing controller for operating the curing means based on the detected penetration position;
A liquid crystal sealing device for a liquid crystal display element, comprising: A sealing part having a liquid crystal injection port for sealing the outer periphery formed by the semiconductor substrate and the transparent substrate with a predetermined gap width with an adhesive and injecting liquid crystal; and the inside of the sealing part injected from the liquid crystal injection port A liquid crystal sealing method for a liquid crystal display element, wherein the liquid crystal inlet of the liquid crystal display element having a liquid crystal to be filled is sealed with a sealant,
A gap width measuring step for measuring the gap width;
A detecting step for detecting a difference between the gap width measured in the gap width measuring step and a gap width set in advance;
An application step of applying the uncured sealant to the liquid crystal injection port;
An adjusting step of adjusting the gap width by pressing or sucking the semiconductor substrate and the transparent substrate so that the difference detected in the detecting step becomes zero and allowing the sealing agent to penetrate into the liquid crystal injection port; ,
A curing step of detecting the penetration position where the sealing agent has penetrated and curing the sealing agent when the penetration position reaches a predetermined position;
A liquid crystal sealing method for a liquid crystal display element, comprising:

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