JP2871938B2 - Manufacturing method of liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly to a method for manufacturing a liquid crystal display device including an ultrasonic cleaning step for a TFT substrate.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, cleaning of a TFT substrate is performed by using an ultrasonic wave having a high frequency (800 to 1,200).
(kHz) A cassette 5 accommodating a TFT substrate 1 is placed in an ultrasonic cleaning tank 4 provided with a vibrator 5 on the bottom surface, and placed on a support 3. In this case, the TFT substrate 1 was set perpendicular to the vibrator 5. A plurality of cleaning tanks of the cleaning device are installed in parallel, and each of the cleaning tanks is filled with water, an alkali, and an organic solvent (such as Freon and IPA).

In ultrasonic cleaning, ultrasonic waves emitted from a vibrator 5 installed on the bottom of an ultrasonic cleaning tank 4 reach the TFT substrate 1 and are removed and cleaned by shaking particles on the TFT substrate 1. You. The frequency of the ultrasonic wave is 800-1,200
The reason why the frequency is as high as kHz is that at low frequencies (28 to 40 kHz), cavitation occurs and TFT elements are destroyed. At a frequency of 800 to 1200 kHz, cavitation hardly occurs and the TFT element is not destroyed.

[0004]

The directivity of ultrasonic waves increases as the frequency increases. The directivity half angle indicating the directivity is 41 degrees at 28 kHz and 1.3 at 800 kHz.
The degree becomes 1.0 degree at 1,000 kHz. Therefore, FIG.
As shown in (1), if the TFT substrate 1 to be cleaned is installed perpendicular to the ultrasonic vibrator 5, the surface of the TFT element 6 is not irradiated with ultrasonic waves well, and therefore, there is a disadvantage that the cleaning effect is small.

An object of the present invention is to provide a method of manufacturing a liquid crystal display device including a cleaning step having an excellent cleaning effect.

[0006]

SUMMARY OF THE INVENTION The present invention relates to
The method of manufacturing a liquid crystal display device comprising the step of performing ultrasonic cleaning with an ultrasonic frequency of 200kHz, each other Tokoro
A plurality of TFT substrates housed in a cassette arranged in the thickness direction at regular intervals are separated by the T
And performing ultrasonic cleaning by inclining the FT element surface toward the ultrasonic vibrator in the thickness direction at an angle such that the ultrasonic wave does not shadow the adjacent TFT substrate. Here, the cassette is placed
The supported support is moved a distance equal to or more than the pitch of the ultrasonic standing wave.
The separation can be swung up and down.

[0007]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an ultrasonic cleaning tank according to a first embodiment of the present invention, and FIG. 2 is a partially enlarged sectional view illustrating the inclination of the TFT substrate of FIG.

In the first embodiment, as shown in FIG.
The TFT substrate 1 is set to be inclined by θ degrees so that the TFT element surface 6 of the T substrate 1 faces the direction of the ultrasonic transducer 5. Specifically, the support 3 of the ultrasonic cleaning tank 4 is inclined by θ degrees. As a result, the cassette 2 placed on the support 3 and the TFT substrate 1 stored in the cassette 2 are also inclined by θ degrees with respect to the vibrator 5.

Here, as shown in FIG. 2, when the inclination angle θ is increased, the upper part of the TFT substrate 1a is
As a result, the ultrasonic wave is not applied, and the cleaning effect is reduced. Therefore, the length of the TFT substrate 1a is l,
Assuming that the distance between the TFT substrates 1a and 1b is a, the vertical line from the vibrator 5 is connected to the lower end of the TFT substrate 1b and the TFT substrate 1a.
The angle θ = tan ^-1 (a / l) when it is in contact with the upper end of is suitable.

FIG. 3 is a schematic structural view of a cleaning apparatus for explaining a cleaning method according to a first embodiment of the present invention.

In the first embodiment, as shown in FIG.
When the cassette 2 containing the T substrates 1 is supplied from the loader 7, the cassette 2 is first immersed in the alkali bath 8 by the transfer robot 13. Here, after removing the organic dirt, the transfer robot 13 transfers the organic dirt to the rinsing tank 9 to remove the alkali adhering to the TFT substrate 1.

Next, the particles are transferred to an ultrasonic cleaning tank 4 to remove particulate dirt, then washed in a high-speed drain rinse tank 10, and finally dried in a hot pure water pull-drying tank 11 and conveyed to an unloader 12. . The rinsing tank 9, the ultrasonic cleaning tank 4, and the high-speed drain rinsing tank 10 are all filled with pure water.

In the cleaning apparatus having such a structure, the TFT substrate 1 is cleaned.

Here, l = 350 mm (width 3) shown in FIG.
00 mm), a = 7 mm, θ = 0 degrees (conventional example), and 1 degree. As a result, the number of particles having a size of 3 μm or more removed is 10 at θ = 0 degrees (conventional example) θ = 1 degree. By tilting the TFT substrate 1 toward the ultrasonic vibrator 5, particles (dirt) were efficiently removed.

FIG. 4 is a sectional view of an ultrasonic cleaning tank for explaining a second embodiment of the present invention.

In the ultrasonic cleaning, unevenness of cleaning occurs due to generation of a standing wave (the pitch λ / 2 of the standing wave is 25 ° C. in water).
1 mm for 800 kHz and 0.7 mm for 1,000 kHz). The second embodiment is an example in which a swinging mechanism is provided as shown in FIG. 4 in order to prevent the cleaning unevenness.

The support 3 on which the cassette 2 is placed is in contact with the swing cam 14 and moves up and down with the rotation of the swing cam 14. Therefore, the TFT substrate 1 also moves up and down. Here, the distance of the vertical movement is equal to or more than the pitch λ / 2 of the standing wave.

As a result, the number of particles to be removed was 105 at θ = 1 ° under the same conditions as in the first embodiment, and it was confirmed that the particles were removed more efficiently than in the first embodiment.

[0020]

As described above, according to the present invention, by inclining the TFT element surface 6 of the TFT substrate 1 in the direction of the vibrator 5, ultrasonic waves are efficiently radiated to the TFT element surface 6, and therefore, the ultrasonic wave is adhered. This has the effect that particles (dirt) are efficiently removed and a clean TFT element surface 6 is obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of an ultrasonic cleaning tank according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view illustrating the inclination of the TFT substrate of FIG.

FIG. 3 is a schematic configuration diagram of a cleaning apparatus illustrating a cleaning method according to a first embodiment of the present invention.

FIG. 4 is a sectional view of an ultrasonic cleaning tank according to a second embodiment of the present invention.

FIG. 5 is a sectional view of an example of a conventional ultrasonic cleaning tank.

[Explanation of symbols]

 1, 1a, 1b TFT substrate 2 Cassette 3 Support stand 4 Ultrasonic cleaning tank 5 Transducer 6 TFT element surface 7 Loader 8 Alkaline tank 9 Rinse tank 10 High-speed drainage rinsing tank 11 Hot pure water pulling and drying tank 12 Unloader 13 Transport robot 14 Oscillating cam

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/304 B08B 3/12 H01L 21/336 H01L 29/786

Claims (2)

(57) [Claims] 1. A method for manufacturing a liquid crystal display device comprising a step of performing ultrasonic cleaning with ultrasonic waves having a frequency of 800 to 1,200 kHz , wherein a thickness direction of the liquid crystal display device is set at predetermined intervals.
The plurality of TFT substrates housed in a cassette arranged in
The thickness of the FT substrate is set so that the thickness of the
A method of performing ultrasonic cleaning by tilting the liquid crystal device toward the ultrasonic vibrator in the opposite direction . (2) Place the support on which the cassette is placed
Swing up and down a distance greater than the pitch of the ultrasonic standing wave
A method for manufacturing a liquid crystal display device according to claim 1, wherein
Law.