JP3826576B2 - Spacer spraying method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a spacer spraying device used for manufacturing a liquid crystal display element.
[0002]
[Prior art]
The liquid crystal display element has a predetermined gap between the two substrates by joining at least one substrate having a plurality of particulate and columnar spacers arranged on the surface and the other substrate with the spacer interposed therebetween. And a liquid crystal substance is sealed in the predetermined gap.
[0003]
The above-mentioned spacer is made of an insulating resin having a diameter of several μm, spherical fine particles such as SiO 2, or cylindrical glass fibers.
[0004]
The spacer spraying device for arranging the spacers on the substrate includes a stage on which the substrate is placed, a housing for housing the stage, spacer supply means, a nozzle having an injection port facing the housing, and the spacer It is comprised by piping which connects a supply means and the said nozzle.
[0005]
The step of spraying the spacer includes the step of supplying the spacer to the nozzle by a spacer supply means, the step of spraying the spacer into the housing from the nozzle outlet, and the step of attaching the spacer to the substrate surface in the housing. And more is done.
[0006]
The substrate gap of the liquid crystal display element is smaller than the predetermined gap when the number of the spacers is small, or larger than the predetermined gap when the number of spacers is large, so that the liquid crystal material thickness of the liquid crystal display element is formed to a desired thickness. Can not do it. Such non-uniformity of the number of dispersed spacers on the substrate surface or the variation in the number of spacers between the substrates causes display defects such as color unevenness and contrast failure of the liquid crystal display element.
In order to make the above-mentioned non-uniformity of the number of spacers on the substrate and to make the number of spacers uniform among the substrates, after the step of dispersing the spacers on the substrate, the spacers adhered on the substrate are optically removed. Observation and counting are performed to adjust parameters such as spacer spraying conditions, specifically, the jetting time and pressure of compressed gas blown from the nozzle, or the standing time after jetting. The optimum condition was obtained by repeating the counting by optical observation and the adjustment of the spacer spraying condition.
[0007]
[Problems to be solved by the invention]
However, in such a method for obtaining the optimum conditions for spacer spraying, measurement is performed by changing the spacer spraying conditions in various ways, so that a very complicated operation is required and the operating rate of the spacer spraying apparatus is lowered.
[0008]
Even when the optimal conditions for spacer dispersion are set, the spacer supply amount varies due to the spacer adhering to the piping due to the influence of static electricity, etc., and on the substrate surface due to the interaction between the spacer and the substrate, such as static electricity. Due to fluctuations in the amount of adhesion, etc., non-uniformity occurs in the dispersion state of the spacers, resulting in defective cells in which the substrate gap is outside a predetermined range.
[0009]
In order to solve the above-mentioned problems caused by static electricity, the spacer is electrically set to a predetermined potential by ionizing air using a charging device using a corona discharge or the like, or a neutralized state that is not charged positively or negatively, There is also a spacer spraying device in which the charge amount of the spacer is in a predetermined range, but in this system, a charging device or a charge eliminating device must be added, and the actual spacer spray amount cannot be made.
[0010]
The present invention provides a spacer spraying device for manufacturing a liquid crystal display element in which spacers to be sprayed are electrostatically charged and sprayed on a substrate, and a method for spraying spacers sprayed on a substrate using the spacer spraying device. With the goal.
[0011]
[Means for Solving the Problems]
The present invention defines a stage for placing one of a pair of substrates opposed to each other to constitute a liquid crystal display element, a housing for housing the stage, and a pair of substrate gaps opposed to each other. A spacer supplying means for supplying a spacer, a nozzle having an injection port directed into the housing, the spacer supplying means and the nozzle are connected, and the spacer passes through the nozzle together with the nozzle to pass the spacer to a predetermined A pipe to be charged to polarity, a potential measuring means connected on the outer peripheral surface of the pipe, and a charge amount measuring means connected to the stage, for the amount of charge of the substrate generated when the spacer is attached to the substrate The change is detected by a charge amount measuring means connected to the stage, and the charged state of the spacer passing through the pipe is quantified as a potential change by the potential measuring means. Obtained by first order approximation equation with the number of spacers adhered to the pre-determined charge amount and the substrate, and calculates the number of spacers deposited on the substrate for each spraying process.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a spacer spraying device in which a spacer held between a pair of substrates constituting a liquid crystal display element is charged and sprayed while passing a piping member from a spacer supply means to a nozzle.
[0017]
That is, in the spacer spraying device according to the present invention, the spacer and the spacer are caused by the interaction with the passage in the piping member (pipe, nozzle) on the route of the piping member from the spacer supply means to the nozzle having the injection port directed into the housing. The piping member is charged.
This charging phenomenon is controlled by the selection of the material of the piping member or the piping member of the nozzle, and it is charged by the order of the spacer material and the piping member material on the generally well-known friction charging series as shown in FIG. The charge is almost fixed. For example, if the material of the piping member is a material that is more likely to be positively charged on the charging series, the spacer passing through the inside is more likely to be charged by a negative charge, and the material of the piping member is more negative on the charging series. If the material is easily charged with electric charge, the spacer passing through the inside is easily charged with positive charge.
[0018]
Therefore, the polarity of the electric charge charged in the spacer can be selected by selecting at least one material of the pipe and the nozzle for the spacer.
[0019]
The amount of charge of the spacer can be quantitatively measured by providing a potential measuring means on the outer peripheral surface of the piping member and measuring the potential change of the piping member that occurs when the spacer passes.
[0020]
Further, a charge amount measuring means is provided on the stage, and the charge amount of the substrate by the spacer attached to the substrate can be measured. Therefore, the adhesion amount of the spacer to the substrate can be measured based on the charge amount of the spacer and the charge amount of the substrate.
[0021]
According to such a spacer spraying device, the spacer can be uniformly charged without providing a special charging device. By using this charged spacer, the spacer can be sprayed on the substrate effectively and uniformly. can do.
[0022]
Further, by providing the potential measuring means on the outer peripheral surface of the piping member and the charge amount measuring means on the stage, the dispersion state of the spacers can be observed sequentially, so that each liquid crystal cell can be manufactured.
[0023]
Furthermore, since the potential measurement means is provided on the piping member and the charge amount measurement means is provided on the stage to measure the respective charge amounts, it is caused by the spacer supply means or other factors when an abnormality occurs in the dispersion of the spacers. It can be determined whether it is abnormal, and work such as adjustment of the spacer spraying device can be shortened.
[0024]
【Example】
An embodiment of the present invention will be described below with reference to FIGS.
In a liquid crystal display element in which a liquid crystal substance is sealed between a pair of substrates, a particulate or columnar spacer that regulates a gap between the substrates is disposed on at least one substrate. This spacer is made of an insulating resin having an outer diameter of several μm, spherical fine particles such as SiO2, or columnar glass fibers. Then, a liquid crystal substance is sealed in the substrate gap that holds the spacer.
[0025]
FIG. 2 shows a structural diagram of the spacer spraying device. The spacer spraying device includes a housing 10 for storing a substrate 13 on which the spacer 1 is sprayed, and a storage container 2a for storing the spacer 1 and a weighing device 2b. Spacer supply means 2 for supplying the spacers one by one, a pipe 3 constituting a pipe member for transferring the spacer 1 supplied from the spacer supply means 2, and an injection port connected to the pipe 3 in the housing 10 It consists of a nozzle 4 arranged facing.
[0026]
Around the casing 10, an exhaust port (not shown) provided on the lower surface is connected to an exhaust facility of a factory facility. In addition, a stage 12 is provided inside the housing 10, and a substrate 13 is placed on the stage 12.
[0027]
In the spacer spraying apparatus of the present embodiment, a potential measuring means is connected to the pipe 3 which is one of the above-described piping members via a metal foil-like electrode 3a wound around the outer peripheral surface and a conducting wire. 3 can be measured and recorded over time using a potential difference recorder 20 such as an oscilloscope or a memory recorder. Thereby, the potential change of the pipe 3 accompanying the passage of the spacer 1 can be measured, and the potential change of the pipe 3, that is, the potential change state of the spacer 1 can be quantitatively measured.
[0028]
Further, in the spacer spraying apparatus of the present embodiment, the stage 12 is connected with a charge level meter 21 as charge amount measuring means. The charge level meter 21 measures a potential (V) due to charges accumulated in a capacitor having a certain capacity connected between the ground and the detection electrode terminal 21a. Thereby, the potential change (ΔV) of the substrate 13 accompanying the adhesion of the spacer 1 can be quantitatively measured.
[0029]
The operation of the spacer spraying device of this embodiment will be described below. First, the substrate 13 is placed on the stage 12. On the other hand, in the spacer supply means 2, the spacer weighed in a predetermined amount is conveyed by compressed gas (for example, dry air or nitrogen). The gas containing the spacer 1 is injected into the housing 10 through the pipe 3 and the nozzle 4 which are pipe members. A part of the spacer 1 reaching the inside of the housing 10 adheres to the substrate 13 and the rest is discharged to the outside together with the transporting compressed gas.
[0030]
At this time, when the spacer 1 passes through the piping members of the piping 3 and the nozzle 4, static electricity is generated due to friction with the piping members and the spacer is charged. Since the state of this charging varies depending on the material of the piping member, it can be controlled by selecting the piping member. When the piping member is a material that is more easily charged with a positive charge than the spacer material on the frictional charging series shown in FIG. 1, the spacer 1 is charged with a negative charge and is more easily charged with a negative charge than the spacer material. Then, the spacer 1 is charged to a positive charge. The materials used for the pipe 3 are arranged in the order of glass, nylon, brass, and aluminum in the order of materials that are easily charged to a positive charge, and in the order of materials that are easily charged to a negative charge, such as fluororesin and stainless alloy (SUS304) .
[0031]
In the spacer spraying device of the present embodiment, the charged state of the piping member can be quantitatively measured by the potential difference recorder 20 connected to the outer peripheral surface of the piping member.
[0032]
It records the time change of the potential difference between the piping member and the earth when the spacer 1 passes, and obtains the integrated value (integrated value) of the potential corresponding to the passing time zone of the spacer 1 from the recorded result. Measured based on the standardized value (hereinafter referred to as power). When this integral value is large, it indicates that the spacer 1 is more charged, and when it is small, it indicates that the spacer 1 is not charged so much.
[0033]
Further, the charge level meter 21 connected to the stage 12 measures a change (ΔV) in the charge amount of the substrate 13 due to the spacer 1 adhering to the substrate 13. This change in charge amount and the number of spacers 1 attached to the substrate 13 can be approximated as a linear function. Therefore, the number of spacers 1 on the substrate 13 can be known without observing the spacers 1 on the substrate 13 and counting the number.
[0034]
Next, the measurement result by the potential measuring means of the spacer spraying device of the present embodiment will be shown. By changing the material of the pipe 3 connecting the spacer supply means 2 and the nozzle 4, the potential of the outer peripheral surface of the pipe 3 changes as the spacer 1 passes through the pipe, that is, the charged state of the spacer 1 FIG. 3 shows that varies depending on the pipe material. The vertical axis represents the piping material, and the horizontal axis represents the electric power. The electric power refers to a value obtained by dividing the waveform area by the weighed value of the spacer 1 from the peak waveform area measured by the potentiometer 20 and converting it per unit amount.
[0035]
According to FIG. 3, the positive / negative direction and the magnitude of the potential of the pipe 3 change depending on the material of the pipe 3. This indicates that the spacer 1 that has passed through friction with the inner wall of the pipe 3 is charged with an opposite sign. When nylon resin is used for the pipe 3, the pipe 3 has a positive potential, and when Teflon, which is a fluororesin, is used, it has a large negative value. In copper and stainless alloy (SUS316), the potential changes almost. It can be seen that aluminum and brass change slightly in the positive potential direction. These orders are consistent with the order of the triboelectric series generally known for static electricity. That is, nylon resin (positive potential direction) is selected as the pipe 3 to charge the spacer 1 to a positive potential, and fluororesin (negative potential direction) is selected as the pipe 3 to charge the spacer 1 to a negative potential. Is preferred.
[0036]
Next, the measurement result by the charge amount measuring means is shown in FIG. FIG. 4 shows the relationship between the change in charge amount (ΔV) of the substrate 13 due to the adhesion of the spacer 1 and the number of spacers on the substrate 13. The horizontal axis represents ΔV, and the vertical axis represents the number of spacers per unit area (1 mm 2 in the figure). In the series shown in the figure, the ♦ mark is a combination of the nozzle 4 made of stainless steel (SUS304) and the pipe 3 is stainless steel alloy (SUS316), and the ◇ mark is the nozzle 4 made of stainless steel alloy (SUS304) and the pipe 3 is made of fluororesin (Teflon). The combination, □ is measured by combining the nozzle 4 with aluminum and the piping 3 with a combination of fluororesin (PFA resin), and the ■ marking is measured with a combination of the nozzle 4 with aluminum and the piping 3 with a nylon resin.
[0037]
In any case, there is a strong correlation between ΔV and the number of spacers attached to the substrate 13.
[0038]
From these accumulated data, it is possible to find a linear approximation between ΔV and the number of spacers, and to derive the number of spacers from the measured ΔV. Therefore, a predetermined amount of charge derived from this first-order approximation is detected, and at that time, for example, by controlling the spraying operation such as stopping the supply of the compressed gas transporting the spacer 1, an appropriate amount of the spacer 1 is placed on the substrate 13. Can be attached to.
[0039]
In addition, regarding the nozzle 4 that is a piping member as in the case of the pipe 3, FIG. 4 shows that the direction of the potential to be charged differs depending on whether the material of the nozzle 4 is stainless alloy (SUS304) or aluminum. This is a reflection of the difference in charging due to the difference in the material of the piping member described above, and the charged state of the spacer 1 can be controlled by changing the material of the nozzle 4 instead of the material of the piping 3. The force is more remarkable than the material of the pipe 3 described above.
[0040]
【The invention's effect】
The present invention is implemented in the form as described above, and has the following effects.
[0041]
With respect to the difference in spacer material (particle material, presence / absence of surface treatment), an appropriate charging process can be performed by changing the material of at least one of the piping members and the piping.
[0042]
That is, by controlling the charging of the spacers with the piping material, the amount of charging of the spacers can be controlled stably, and fluctuations in the number of spacers adhering to the substrate every number of processings can be prevented. This control of the charge amount of the spacer causes various problems such as deterioration in performance due to environmental factors such as humidity, deterioration of the electrodes due to changes over time, and contamination that have occurred using a method using a conventional charging device or static elimination device. I will not let you.
[0043]
In addition, it is possible to measure the number of spacers attached to the substrate from the change in the amount of charge on the substrate before and after spraying the spacers, and it is possible to grasp the state of the spacer spraying device in a timely manner. The concentration can be set. And, it is possible to quantitatively evaluate in-line rather than observing and counting the spacers on the substrate as in the past, and the spacer spraying condition on the substrate is greatly increased. Can be shortened.
[Brief description of the drawings]
FIG. 1 is a diagram showing a triboelectric charging series.
FIG. 2 is a structural diagram of a spacer spraying device according to an embodiment of the present invention.
FIG. 3 is a graph showing the relationship between piping material and piping surface potential.
FIG. 4 is a graph showing the charge amount of a substrate and the number of spacers.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Spacer 2 Spacer supply means 3 Piping 4 Nozzle 10 Case 11 Mounting hole 12 Stage 13 Substrate 20 Potential difference recorder 21 Charging level meter

Claims (1)

A stage for placing one of a pair of substrates opposed to each other to constitute a liquid crystal display element, a housing for housing the stage, and a spacer for defining the gap between the pair of substrates disposed opposite to each other A spacer supplying means for supplying the nozzle, a nozzle having an injection port directed into the housing, the spacer supplying means and the nozzle are connected, and the spacer passes through with the nozzle to charge the spacer to a predetermined polarity. A pipe, a potential measuring means connected on the outer peripheral surface of the pipe, and a charge amount measuring means connected to the stage, and a change in the charge amount of the substrate that occurs when the spacer adheres to the substrate is placed on the stage. Detected by the connected charge amount measuring means, and obtained by quantifying the charged state of the spacer passing through the pipe by the potential measuring means as a potential change. Advance by determined charge amount and the primary approximate expression between the number of spacers deposited on a substrate, the method of application of the spacer, characterized in that to calculate the number of spacers deposited on the substrate for each spraying process.

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