JPH05267264A - Manufacture of liquid-crystal display device - Google Patents

Abstract

PURPOSE:To obtain a clean TFT element face by a method wherein a contamination which has adhered to the surface of a TFT substrate is removed with good efficiency. CONSTITUTION:A TFT element face 6 on a TFT substrate 1 is tilted toward an oscillator 5 with reference to the oscillator 5 which generates ultrasonic waves. The ultrasonic waves which are radiated from the oscillator 5 are impinged on the TFT element face 6 with good efficiency; a contamination is removed with good efficiency; the TFT element face 6 which is clean can be obtained.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, cleaning of a TFT substrate requires ultrasonic waves (800 to 1,200) having a high frequency.
(KHz) Transducer 5 is placed in the ultrasonic cleaning tank 4 on the bottom surface of which the cassette 2 containing the TFT substrate 1 is placed and placed on the support 3. In this case, the TFT substrate 1 was installed vertically to the vibrator 5. A plurality of cleaning tanks of the cleaning device are installed in parallel, and the cleaning tanks are filled with water, an alkali, and an organic solvent (CFC, IPA, etc.), respectively.

In the ultrasonic cleaning, ultrasonic waves emitted from a vibrator 5 installed on the bottom surface of an ultrasonic cleaning tank 4 reach the TFT substrate 1 and swing and move particles on the TFT substrate 1 to remove and clean them. It The frequency of ultrasonic waves is 800 to 1,200
The reason why it is as high as kHz is that the TFT element is destroyed due to the occurrence of cavitation at a low frequency (28 to 40 kHz). Cavitation hardly occurs at a frequency of 800 to 1,200 kHz, and the TFT element is not destroyed.

[0004]

The directivity of ultrasonic waves becomes stronger as the frequency becomes higher. The directivity half-angle showing directivity is 41 degrees at 28 kHz and 1.3 at 800 kHz.
It becomes 1.0 degree at 1,000 kHz. Therefore, FIG.
As shown in FIG. 3, if the TFT substrate 1 to be cleaned is installed vertically to the ultrasonic transducer 5, the surface of the TFT element 6 is not well irradiated with ultrasonic waves, and therefore 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 process having an excellent cleaning effect.

[0006]

SUMMARY OF THE INVENTION The present invention is 800-1,
In a method of manufacturing a liquid crystal display device, which includes a step of ultrasonic cleaning with ultrasonic waves having a frequency of 200 kHz, a plurality of TFT substrates housed in a cassette are formed on a TFT element surface of an adjacent TFT substrate. The method includes a step of performing ultrasonic cleaning by inclining to an ultrasonic transducer side at an angle that does not shade the ultrasonic waves.

[0007]

Embodiments of the present invention will now 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 for explaining the inclination of the TFT substrate of FIG.

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

Here, as shown in FIG. 2, when the tilt angle θ is increased, the upper portion of the TFT substrate 1a is adjacent to the adjacent TFT substrate 1.
The shadow of b is generated, ultrasonic waves are not irradiated, and the cleaning effect is adversely affected. Therefore, if the length of the TFT substrate 1a is 1,
When the distance between the TFT substrates 1a and 1b is a, the perpendicular line from the vibrator 5 is the lower end of the TFT substrate 1b and the TFT substrate 1a.
An angle of about θ = tan ⁻¹ (a / l) when touching the upper end of is appropriate.

FIG. 3 is a schematic configuration diagram of a cleaning apparatus for explaining the cleaning method of the first embodiment of the present invention.

In the first embodiment, as shown in FIG.
When the cassette 2 accommodating the T substrate 1 is supplied from the loader 7, it is first immersed in the alkaline tank 8 by the transfer robot 13. After the organic dirt is removed here, the transfer robot 13 moves the rinse tank 9 to remove the alkali adhering to the TFT substrate 1.

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

The cleaning of the TFT substrate 1 is performed in the cleaning device having such a structure.

Here, l = 350 mm (width 3 shown in FIG. 2
00 mm), a = 7 mm, θ = 0 degree (conventional example), and as a result of cleaning under conditions of 1 degree, the number of particles of 3 μm or more removed is 10 at θ = 0 degree (conventional example) θ = 1 degree The number was 62 and the particles (dirt) were efficiently removed by tilting the TFT substrate 1 toward the ultrasonic vibrator 5.

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

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

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

As a result, under the same conditions as in the first embodiment, the number of particles removed was 105 at θ = 1 degree, 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 element surface 6 of the TFT of the TFT substrate 1 toward the vibrator 5, ultrasonic waves are efficiently irradiated to the TFT element surface 6 and thus adhered. This has the effect that particles (dirt) are efficiently removed and a clean TFT element surface 6 is obtained.

[Brief description of 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 an inclination of the TFT substrate of FIG.

FIG. 3 is a schematic configuration diagram of a cleaning device for explaining 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 4 Ultrasonic cleaning tank 5 Transducer 6 TFT element surface 7 Loader 8 Alkali tank 9 Rinsing tank 10 High-speed drainage rinse tank 11 Hot deionized water drying tank 12 Unloader 13 Transfer robot 14 Swing cam

Claims (1)

[Claims] 1. A method of manufacturing a liquid crystal display device, which comprises a step of ultrasonic cleaning with ultrasonic waves having a frequency of 800 to 1,200 kHz, wherein a plurality of TFT substrates housed in a cassette are provided on each of the TFT substrates. A method for manufacturing a liquid crystal display device, comprising the step of performing ultrasonic cleaning by inclining the element surface toward the ultrasonic transducer side at an angle that does not shade the ultrasonic waves of the adjacent TFT substrate.