JP4392692B2 - Semiconductor wafer and liquid crystal glass air levitation transfer device - Google Patents

Description

  The present invention relates to a technique for non-contact conveyance of a wafer or a glass substrate by air levitation between manufacturing processes of a semiconductor and a liquid crystal panel.

  Electronic parts such as liquid crystal glass substrates and semiconductor wafers are becoming larger, and defective products due to the attachment of minute dust, etc. will be observed in the manufacturing process. The method is adopted. That is, as shown in FIG. 1, a porous body 53 such as ceramics or metal or a honeycomb body is disposed on a pressure case 52 to which pressure air from the compressor 51 is fed, and from the porous body 53 of the pressure case 52. A system is known in which the transported object 55 is levitated by the ejected fluid film 54 (see Patent Document 1). However, the porous body 53 is disadvantageous in that it has a high pressure loss and is easily clogged, and a pressurizing device such as a compressor is required, and the supply of clean air complicates the air piping.

In addition, as shown in FIG. 2, when the transported object 55 is passed above the fan filter unit 56, means for placing and guiding rollers 57 on both sides of the transported object 55 is also employed (Patent Document). However, if the transported object is made of glass or the like, a situation may occur in which the glass end face is damaged.
JP 2005-8368 A JP 2002-151570 A

In view of the above points, the present invention eliminates the use of a porous body that blows up a fluid film that floats the object to be transported, eliminates fluctuations in the flying height of the transported object due to clogging of the fluid film, and the like. One of the challenges is to be able to maintain the flying height.
Also, as one of the issues to keep the surroundings of the transported object in a clean environment, the fluid for floating the transported object is blown out through the hepa filter, so that the transported object is transported at the same time. It is possible to supply clean air around objects.
Furthermore, it is an object to enable the guided object to be guided in a predetermined direction by blowing an airflow onto the end surface of the conveyed object.

The invention according to claim 1 is a device for levitating and transporting an object to be transported made of a plate-like body such as a semiconductor wafer and liquid crystal glass, and a sheet-like filter medium is continuously formed in a V-shape below the transport path. The one side constituting the V-shape is made longer than the other side, and the center line of the V-shaped space passing through the opening that opens in the direction in which the clean air that has passed through the filter flows out is inclined to produce the clean airflow. It is possible to install a filter with a slanted blow direction so that the slanted airflow strikes the end of the transported object, and floats and transports the transported object, and levitates and surrounds the transported object with a clean jet stream. It is said.

The apparatus of the present invention is a device for levitating and transporting an object to be transported composed of a semiconductor wafer and a plate-like body such as liquid crystal glass, and refracting a sheet-like filter medium into a continuous V-shape at the lower part of the transport path. The direction of the clean air flow is slanted by inclining the center line of the V-shaped space passing through the opening that opens toward the direction in which the clean air that has passed through the filter flows out, with one side constituting the length longer than the other side A filter is provided so that an oblique airflow strikes the end of the object to be conveyed, and the object to be conveyed is levitated and conveyed, and the area around the object to be conveyed is surrounded by a clean jet stream. It is possible to fill the periphery of the object with clean air, which is effective in preventing the contamination of the object to be conveyed during the conveyance.

  Since the device of the present invention has the V-shaped configuration described above, the clean air blown from the filter can apply an oblique airflow to the object to be conveyed without providing, for example, a grill or an inclined slit for changing the flow of the clean air. .

FIG. 3 shows an overall perspective view of the levitation transfer apparatus 1 of the present invention.
A plurality of fan filter units 3 for placing an object to be conveyed 2 such as a glass substrate or a wafer on the upper surface and conveying it in a predetermined direction are continuously supported on the frame 4 until a predetermined length is reached. Inside the fan filter unit 3, there are provided a fan 5 for taking in air from the outside of the fan filter unit 3 and a hepa filter 6 for filtering the air and ejecting it out of the filter unit 3 as clean air.

  Although the upper surface of the fan filter unit 3 is not shown, a punching plate is stretched, and the clean air that has passed through the internal hepa filter blows out from the punching plate to the upper surface. Roller bearings 8 are provided on both side surfaces of the fan filter unit 3 in the transported object transport direction to guide the transported object 2 so as not to drop off from the fan filter unit 3.

  An inclined slit plate 9 is provided so as to cover the upper surface of the fan filter unit 3. The inclined slit plate 9 is provided with slits 10 having a predetermined interval in a direction intersecting with the conveyance direction of the object to be conveyed 2, and the edge of the slit 10 in the direction intersecting with the object conveyance direction is inclined, The clean air that has passed through the slit 10 flows obliquely in the direction in which the object 2 is pushed.

  Further, when the clean air that has passed through the hepa filter 6 flows out of the hepa filter 6 by changing the refraction angle of the hepa filter 6 in the fan filter unit 3 without using the inclined slit plate 9 as described above, the outflow angle thereof. Can be slanted. FIG. 5 shows a cross section of the hepa filter 6. The hepa filter 6 refracts the sheet-like filter medium 7 in a zigzag continuous V-shape and cleans it by passing air through its refracting surface. However, when one of the two sides of the V-shape is shortened as shown in FIG. 5, the V-shape passes through the opening 6b that opens in the direction in which the clean air that has passed through the filter flows out. The center line L of the space 6a can be inclined, and the continuous V-shape is inclined to the long side. When clean air is passed through the space 6a, the clean air that has passed through the filter 6 is indicated by an arrow A in FIG. As shown in the figure, the flow is inclined toward the long side of the V-shape, and is in contact with the conveyed object 2 obliquely, and the conveyed object 2 is pushed rightward in FIG.

  A plurality of fan filter units 3 are connected and used in accordance with a predetermined transport length as described above. However, there is a case where the progress of the transported object must be stopped in the middle of the fan filter unit 3. Must be stopped. For this purpose, end stoppers 16 and 16 and an intermediate stopper 17 are provided at appropriate positions at both ends and in the middle of the row of fan filter units 3. The stopper is configured so that the shaft is electrically extended by a solenoid or the like to the conveyed object passage so that the conveyed object 2 comes into contact therewith and stops.

  Further, in order to make the periphery of the fan filter unit 3 a cleaning space, as shown in FIG. 6, the upper side surface of the fan filter unit 3 may be covered with a shielding plate 18 and the whole may be surrounded by a cover 19. . With this configuration, the clean air 20 ejected from the fan filter unit 3 and pushing the object to be conveyed 2 flows out of the apparatus through the space between the shielding plate 18 and the cover 19 and is subject to external contamination. There is no.

In the apparatus of the present invention, the fan filter unit 3 with the hepa filter 6 incorporated therein is used, the differential pressure P between the conveyed object and the hepa filter surface is measured, and the flying height can be controlled.
As shown in FIG. 7, a differential pressure gauge 21 for detecting a differential pressure between the two parts is provided below the clean air ejection part of the fan filter unit 3 and the transported object 2.

式１より、同一重さ（Ｍｇ一定）であるならば、差圧Ｐと浮上高さｈは反比例する。式２より、同一面積（Ａ一定）であるならば、風速と持ち上げられる重さは比例する。

From Equation 1, if the weight is the same (Mg constant), the differential pressure P and the flying height h are inversely proportional. From Equation 2, if the area is the same (A constant), the wind speed is proportional to the lifted weight.

The schematic block diagram which shows the conveyance system by the conventional air. The schematic block diagram which shows the guide system by the conventional roller. A is a schematic perspective view of the device of the present invention. B is a sectional view of the fan filter unit. Explanatory drawing which shows the conveyance system by an inclination slit board. Explanatory drawing which shows the conveyance system by an inclination hepa filter medium. Schematic of the air purification of conveyance space. Schematic of a fan filter unit provided with a differential pressure gauge.

DESCRIPTION OF SYMBOLS 1 Floating conveyance apparatus 2 Conveyed object 3 Fan filter unit 4 Frame 5 Fan 6 Hepa filter 6a V-shaped space 6b Opening part 7 Filter medium 8 Roller bearing 9 Inclined slit board 10 Slit 16 End stopper 17 Intermediate stopper 18 Shielding board 19 Cover 20 Clean air 21 Differential pressure gauge

Claims (1)

A device for levitating and conveying a substrate made of a semiconductor wafer and liquid crystal glass or the like, wherein a sheet-shaped filter medium is refracted into a continuous V shape at the bottom of the conveyance path, and one side constituting the V shape is A filter with a clean air flow direction inclined is provided by inclining the center line of the V-shaped space that passes through the opening that opens toward the direction in which the clean air that has passed through the filter flows out. An air levitation conveying apparatus characterized in that an oblique airflow strikes an end of a conveyed object, levitates and conveys the object to be conveyed, and surrounds the object to be conveyed with a clean jet stream .

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