JPH1114954A - Manufacturing method of liquid crystal display element - Google Patents

Abstract

(57) [Summary] [Problem] By detecting a wide range of spacer particle scattering density and spacer particle aggregation in a short time, adjusting the spacer particle scattering amount and cleaning timing of the spacer particle scattering device based on the inspection result, Reduces manufacturing costs. An agglomeration and scattering density of spacer particles are detected at high speed over the entire surface of a substrate by a spacer particle detection device. By monitoring the state of occurrence of aggregation, the cleaning process is performed with the timing of cleaning the spacer particle spraying device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for dispersing particles on an object, and more particularly to dispersing spacer particles used in a liquid crystal display device or the like.

[0002]

2. Description of the Related Art In a liquid crystal display device, for example, the accuracy of the distance between two glass substrates sandwiching liquid crystal, ie, the accuracy of a cell gap, greatly affects the characteristics and display quality of the liquid crystal display device. For this reason, in order to keep the cell gap constant in the manufacturing process of the liquid crystal display element, spacer particles having a particle size of several micrometers are used, and extremely high-precision spacer particles are dispersed over the entire surface of the glass substrate. Two substrates are overlapped. Therefore, in order to make the cell gap constant over the entire surface of the substrate with high accuracy, the number of spacer particles per unit area, that is, the application density and the presence or absence of aggregation of the spacer particles are important management items.

[0003] With the increase in substrate size (several hundred mm square or more), the demand for uniform dispersion density of spacer particles in the substrate surface has become severe. It is important to measure the particle scattering density and feed it back to the spraying conditions.

[0004] In addition, since the aggregation of the spacer particles causes large gap unevenness, if there is even one point in the substrate, the product will be defective. Therefore, it is necessary to inspect the entire surface of all the substrates to determine the presence or absence of aggregation.

[0005] Conventionally, as a method for inspecting the scattering density of spacer particles, there is a method disclosed in, for example, JP-A-5-46828, and a method for inspecting aggregation of spacer particles is disclosed in, for example, JP-A-7-35696. There was something.

[0006]

However, in the conventional methods for inspecting the agglomeration and scattering density of the spacer particles, it is necessary to detect the individual spacer particles at a relatively high resolution in order to make them appear. Since the detection field of view is narrowed to detect individual spacer particles at a resolution that can be identified, when inspecting the entire surface of the substrate, it is necessary to provide a large number of detection optical systems or use a single detection head to Inspection must be performed by scanning twice. Providing a large number of detection optical systems leads to an increase in inspection cost, and there is a problem in that if scanning is performed a plurality of times over time, it becomes impossible to meet the tact time of the manufacturing line, so that inspection of all substrates cannot be performed. Therefore, it has been difficult to adjust the amount of spacer particles to be scattered according to the density of spacer particles to be scattered on the substrate.

[0007] Further, in performing the entire inspection of the substrate, it is necessary to correct the luminance unevenness in the detection visual field due to the cause of the irregular illumination or the like and to make the detection sensitivity in the visual field constant. However, since the brightness distribution in the detection visual field is different between the spacer particle aggregation and the spacer particle, it was not possible to correct the aggregation and the scatter density simultaneously with one type of correction data to make the sensitivity constant.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to separately correct the brightness of spacer particle aggregation and spacer particles, and simultaneously detect the aggregation and scattering density of the spacer particles over the entire surface of the substrate at the same time at high speed. In addition to managing the state of spacer particle adhesion in the sprayer by adjusting the cleaning timing of the machine, the spacer particle spray amount on the substrate is adjusted by changing the spacer particle spray condition according to the spacer particle spray density measurement result. .

[0009]

FIG. 1 shows an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a spacer particle dispersing device, 2 denotes a spacer particle dispersing process controller, and 100 denotes a spacer particle detecting device. In this embodiment, after the spacer particles are sprayed on the substrate by the spacer particle spraying device 1,
Spacer particle agglomeration is detected by the spacer particle detection device 100, and when the agglutination occurrence state exceeds a certain standard, cleaning processing of the spraying device is performed. The cleaning process is to remove the spacer particles adhered in the spraying device. In addition, the spacer particle scattering density is measured by the spacer particle detecting device 100, and based on the measurement result, the spraying process controller 2 determines the spacer particle spraying time using the relationship as shown in FIG. Is to adjust.

According to the present embodiment, the cleaning timing of the spacer particle disperser is controlled to control the state of adhesion of the spacer particles in the disperser, and the condition for dispersing the spacer particles is changed according to the result of measuring the spacer particle dispersal density. The amount of the spacer particles sprayed can be adjusted, thereby improving the display quality of the product, preventing the occurrence of product defects, and reducing the product manufacturing cost.

FIG. 3 shows an embodiment of the spacer particle detecting apparatus. Reference numeral 101 denotes an illumination device, which can use a known technique such as an optical fiber light guide or a laser light generator. Reference numeral 200 denotes a transport system for transporting the substrate 3, and a known technique such as a roller or a stage can be used. 102
Is a lens, 103 is an image sensor such as a linear image sensor, 301 is an AD converter, 302 is a brightness correction circuit, 303 is a binarization circuit, 304 is a pass / fail judgment unit, 305 is an area conversion circuit, 306 is a brightness-spacer. 3 shows a particle scattering density conversion unit.

[0012] The spacer detecting device is provided with
The substrate is illuminated by the illuminating device 101 while transporting the substrate. Spacer particles 4 and spacer particle aggregation 5 scattered on the substrate
The scattered light from the light is collected by a lens 102 and photoelectrically converted by a linear image sensor 103. After the photoelectrically converted analog signal is converted into a digital signal by the AD converter 301, luminance correction is performed by the luminance correction circuit 302.

As shown in FIG. 4, the brightness correction circuit includes a spacer particle agglutination detection 401, a spacer particle scattering density detection 402, a metal foreign matter detection 403, an organic foreign matter detection 404, and a fibrous foreign matter detection 405, respectively. Built-in brightness correction circuit according to the detection target, arbitrarily switch or reserve
It is a circuit that can be added in any number as in 07. Brightness correction data as shown in FIG. 5B is stored in the brightness correction circuit corresponding to the detection target, and correction is performed for each pixel by the following equation.

[0014]

A (x) = k × i (x) / s (x) (Equation 1) where k is a constant, x is a pixel number in the linear image sensor 103, and i is from the AD converter 301. Is the input signal.
In addition, s (x) is luminance correction data, which indicates data obtained by spraying a detection target on a substrate in advance. By this luminance correction, the luminance is corrected as shown in FIG.

The luminance correction data is obtained by scattering the detection target on the substrate. When the scatter density is low, only the luminance data at several points within the detection range can be obtained as shown in FIG. In this case as well, the maximum value of the detected luminance is set as the luminance to be detected, and the luminance data can be created by performing interpolation as shown in FIG. As the interpolation curve, a general interpolation curve such as linear interpolation or multi-order curve interpolation can be used.

The luminance-corrected data is supplied to a binarizing circuit 303.
In, the aggregation portion 5 is detected by threshold processing. When there are a plurality of detection targets as shown in FIG. 4, a binarization circuit having a threshold value corresponding to each detection target is provided. Then, the pass / fail judgment unit 304 judges whether the state of occurrence of aggregation exceeds a certain standard, and generates a signal when the state of aggregation is exceeded. On the other hand, the area adding circuit 305 divides the detected image into m × n pixels as shown in FIG. 7 (m and n can be set to arbitrary values), and sets the brightness of m × n pixels in each area. Are added to each other to obtain an average value, which is used as the luminance of the area. Next, the brightness-scattering density conversion unit 306 calculates the spacer particle scattering density for each region using the data indicating the relationship between the detected brightness and the spacer particle scattering density, which is measured in advance, as shown in FIG. Ask.

According to the present invention, it is possible to simultaneously detect spacer particle agglutination and spray density measurement over the entire substrate in-line with respect to all the substrates, and to provide real-time feedback of spacer particle scattering conditions. The quality can be improved, and the occurrence of product defects can be prevented, leading to a reduction in product manufacturing costs.

Another embodiment of the present invention is shown in FIG. As a lens for collecting the scattered light of the spacer particles, a plurality of refractive index distribution lenses 501a and 501b having a detection visual field corresponding to 1 to 10 pixels of the sensor when projected on a linear image sensor are arranged. In addition, as shown in FIG.
A structure in which a plurality of lenses 102a and 102b are arranged may be used.

In a normal lens, the resolution is high at the center of the detection visual field, and the resolution decreases as it approaches the periphery. For this reason, in the case of spacer particles that are detected to be lower than the resolution and spacer particles that are detected to be higher than the resolution, the difference in the lens resolution between the center and the periphery of the visual field affects the detection brightness differently. Two types of luminance correction data for particle detection and aggregation detection are required.

In this embodiment, by arranging a plurality of lenses and narrowing the detection field of view of each lens (usually about 1 to 10 pixels), the difference in lens resolution between the center and the periphery of the field of view is reduced, and one type of lens is obtained. The correction data simultaneously corrects the detected brightness of the spacer particles and the aggregation.

According to the present invention, since the spacer particle aggregation and the spacer particle scattering density can be simultaneously detected with one type of luminance correction data without depending on the resolution or resolution of the lens, the inspection cost can be reduced.

Another embodiment of the present invention is shown in FIG. The scattered light intensity distribution largely depends on the illumination direction. By illuminating so that the angle θ between the illumination light incident direction 601 and the detection direction 602 is always constant at all positions on the detection range 600, the spacer particles are not affected by the scattering characteristics of the detection target. And foreign substances can be detected.
As one embodiment for performing such illumination, there is an apparatus configuration in which a plurality of laser light generators 603a and 603b are arranged as shown in FIG. As shown in FIG. 13, a mirror 604 that reflects light so that illumination light is emitted at a predetermined angle to each point in the detection range, a polygon mirror 605, and a laser generator 60.
An apparatus configuration using 3 may be used.

According to the present invention, since the detection can be performed without being affected by the scattering characteristics of the object to be detected, the agglutination detection rate and the accuracy of measuring the scattering density can be improved.

Another embodiment of the present invention is shown in FIG. FIG.
In the spacer particle dispersing apparatus 1 described above, a plurality of spacer particle dispersing nozzles 701a and 701b are provided, and the spacer dispersing density on the substrate 3 is adjusted by adjusting the amount of spacer particle dispersing at each nozzle.

According to the present invention, it is possible to uniform the distribution density of the spacer particles with high accuracy and to improve the display quality of the product.

[0026]

According to the present invention, it is possible to detect the spacer particle scattering density and the spacer particle aggregation over the entire surface of the entire substrate, and adjust the spacer particle scattering amount and the spacer particle scattering based on the inspection result. Since the cleaning timing of the apparatus can be set, the display quality of the product can be improved, and the production cost can be suppressed by preventing the occurrence of product defects.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a method for obtaining a spray time from a measured spacer particle spray density.

FIG. 3 is a diagram illustrating a configuration of an embodiment of a spacer particle detection device.

FIG. 4 is a diagram illustrating a configuration of a luminance correction circuit.

FIGS. 5A to 5C are graphs of waveforms used for luminance correction.

FIGS. 6A and 6B are explanatory diagrams of luminance data to be detected.

FIG. 7 is an explanatory diagram showing an area of the area addition circuit.

FIG. 8 is an explanatory diagram of a method for obtaining a scatter density from detected luminance.

FIG. 9 is a diagram illustrating an example of components of another embodiment of the present invention.

FIG. 10 is a diagram illustrating an example of components of another embodiment of the present invention.

FIG. 11 is a diagram illustrating a configuration of another embodiment of the present invention.

FIG. 12 is a diagram illustrating an example of components of another embodiment of the present invention.

FIG. 13 is a diagram illustrating an example of a component according to another embodiment of the present invention.

FIG. 14 is a diagram showing a configuration of another embodiment of the present invention.

[Explanation of symbols]

1 ... spacer particle spraying device, 2 ... spraying process controller, 3 ... substrate, 4 ... spacer particles, 5 ... spacer particle aggregation, 100 ... spacer particle detecting device, 101 ... lighting device, 102
a, 102b… Lens, 103… Linear image sensor, 200…
Transport system, 301 AD converter, 302 Brightness correction circuit, 30
3 ... Binarization circuit, 300 ... Good / bad judgment unit, 305 ... Area addition circuit, 306 ... Brightness-dispersion density conversion unit, 401 ... Brightness correction circuit for spacer particle aggregation detection, 402 ... Brightness for spacer particle dispersion density detection Correction circuit, 403: brightness correction circuit for detecting metal foreign matter, 404: brightness correction circuit for detecting organic foreign matter, 405: brightness correction circuit for detecting fiber foreign matter, 406, 407: spare, 501a, 501b ...
Refractive index distributed lens, 600: detection range, 601: illumination light incident direction, 602: detection direction, 603a, 603b: laser light generator, 6
04… Mirror, 605… Polygon mirror, 701a, 701b… Spacer particle spray nozzle.

Claims (8)

[Claims] In a method of manufacturing a liquid crystal display element using spacer particles in order to keep the distance between two substrates constant in a structure in which a liquid crystal is sandwiched between two substrates,
After spraying spacer particles on one or both of the substrates,
Scattered light detection means for detecting scattered light from the spacer particles, luminance correction means for correcting non-uniformity of luminance within the detection range, spacer aggregation detection means for detecting a spacer particle aggregation portion from the detected luminance, and detection luminance Spacer particle number detecting means for obtaining the number of spacer particles from the signal, signal generating means for outputting a signal corresponding to the number of spacer particles, spray amount adjusting means for adjusting the spacer particle spray amount according to the signal, and spacer particles on the substrate. By using spacer particle scattering means for spraying, detecting the spacer particle aggregation on the substrate by the spacer aggregation detection means, and cleaning the spacer particle scattering means when the number of spacer particle aggregation exceeds a certain standard, thereby removing the spacer particles. In addition to managing the state of adhesion of the spacer particles in the particle scattering means, the space on the substrate is detected by the spacer particle number detecting means. Detecting the particle scattering density, determining the spacer particle spraying condition by the spray amount adjusting means according to the spray density, and adjusting the spacer particle spraying amount by spraying the spacer particles by the spacer particle spraying means. Characteristic liquid crystal display element manufacturing method. 2. A scattered light detecting means and a luminance correcting means according to claim 1, wherein a detection optical system and a plurality of luminance correcting means whose detection resolution or resolution is substantially equal to the size of the particle aggregation to be detected. A method for manufacturing a liquid crystal display element, wherein the number of spacer particles and the aggregation of spacer particles are simultaneously detected by using separate brightness correction data for the spacer particles having a resolution lower than the resolution and the aggregation of the spacer particles having the resolution higher than the resolution. . 3. The brightness correction means according to claim 1, further comprising a spacer particle brightness obtaining means, obtaining brightness data at several points in a detection range, and creating brightness correction data by interpolation. A method for manufacturing a liquid crystal display element, comprising: 4. A scattered light detecting means according to claim 1, wherein a plurality of detection optical systems having a detection visual field corresponding to several pixels of the sensor when projected on a linear image sensor are arranged, A method for manufacturing a liquid crystal display device, wherein spacer particles and spacer particle aggregation are simultaneously detected based on luminance correction data. 5. The scattered light detecting means according to claim 1, wherein the illumination is performed such that the angle between the illumination light incident direction and the detection direction is always constant at all positions within the detection range. Characteristic liquid crystal display element manufacturing method. 6. A method for manufacturing a liquid crystal display device according to claim 1, wherein a plurality of brightness correction means can be added or selected in the brightness correction means according to claim 1. 7. A method for manufacturing a liquid crystal display element according to claim 1, wherein said luminance correction means uses luminance correction data for each detection target. 8. A method for manufacturing a liquid crystal display element according to claim 1, wherein said means for dispersing spacer particles has a plurality of dispersing mechanisms, and the amount of dispersing in the substrate can be adjusted depending on the location.