JP4543794B2 - Flat member conveying device - Google Patents

Description

  The present invention relates to a flat plate member transfer apparatus suitable for use in single wafer transfer of a flat plate member that is not suitable for adhesion of moisture such as a semiconductor wafer.

  In general, in the manufacturing process of glass substrates for flat panel displays such as semiconductor wafers, LCDs (liquid crystal displays), PDPs (plasma displays), ELs (electroluminescent displays), etc. A transport device for transporting the flat plate-like members one by one is installed between the devices.

  FIG. 5 shows a conventional conveying apparatus of this type, and reference numeral 30 in the figure is the casing of this apparatus. The casing 30 is formed with an inlet and a delivery port (not shown) in the front and back directions in the figure, in which a fan filter unit 31 is disposed at the top and a roller conveyor 32 is disposed below the fan filter unit 31. Has been. The roller conveyor 32 conveys both ends of a flat plate member 33 such as a glass substrate carried in from the introduction port to the delivery port while being supported by the guided conveyance roller 32a.

  Between the transport rollers 32a, two sets of floating units 34 for supporting the flat plate member 33 from the back surface side in a non-contact manner are arranged. In this levitation unit 34, a porous ceramic plate 36 is attached to the upper surface of a chamber 35 made of a metal casing, and a compressed air supply pipe 37 is connected to the lower surface of the chamber 35.

  According to the conventional flat plate-shaped member conveyance device having the above-described configuration, a predetermined cleanliness can be maintained in the conveyance path in the housing 30 by the clean air supplied from the fan filter unit 31. Further, both ends of the flat plate member 33 are supported by the conveying roller 32a, and the compressed air supplied from the supply pipe 37 into the chamber 35 is ejected from the porous ceramic plate 36 to support the single plate member 33 in a non-contact manner. Thus, it is possible to prevent bending during conveyance while preventing conveyance traces from being attached to the back surface side of the flat plate member 33.

A configuration similar to that of the transport apparatus is also disclosed in Patent Document 1 below, for example.
JP 2002-289670 A

  In the above conventional flat plate-shaped member conveying apparatus, the fan filter unit 31 can maintain the conveying path in the housing 30 at a desired cleanness, but from the porous ceramic plate 36 of the floating unit 34. The ejected compressed air contains contaminants such as moisture and fine organic substances at the molecular level, and there is a problem that these adhere to the flat plate member 33.

  On the other hand, in the semiconductor wafer and various glass substrates for flat display, when the moisture is adsorbed, the growth of a natural oxide film is promoted, or a metal or an organic substance dissolves in the inside and can become a new contamination source. In particular, it is also known that when a corrosive gas comes into contact with moisture on the surface in the process chamber, gas molecules dissolve into the moisture layer and become active ions to corrode the metal surface.

  In addition, when contaminants such as fine organic substances contained in the compressed air adhere to the wafer or glass substrate, when a metal film is formed in a subsequent process, insulation resistance cannot be obtained, or the metal film May cause peeling.

Therefore, with the recent increase in size and size of the semiconductor wafer and flat display glass substrate, the development of a new transfer device that can prevent this kind of moisture and contaminants from adhering to the transfer device is desired. It is rare.
The present invention has been made in view of such circumstances, and can prevent adhesion of harmful substances such as moisture to the flat plate member during transportation, thereby improving the manufacturing yield and quality of the flat plate member. It is an object of the present invention to provide a flat plate-like member conveying device.

In order to solve the above-mentioned problems, the invention described in claim 1 is a housing having a flat plate-like member introduction port and a delivery port, and is disposed in the housing, from the introduction port toward the delivery port. A conveying means for conveying while supporting both side portions of the flat plate member; and a levitation unit that is arranged in parallel with the conveying means on the back surface side of the flat plate member and floats the flat plate member by the gas to be ejected. In the flat plate-shaped member conveying apparatus having the above, clean dry air (hereinafter referred to as ultra-low dew point air) having an atmospheric pressure dew point of −100 ° C. or less in which the molecular contaminant is removed to 10 ppb or less inside the casing. ) And a second ultra-low dew point air supply pipe for supplying the ultra-low dew point air as a floating gas for the flat plate member to the levitation unit. the providing, or Moisture adhering to the surface of the flat plate member is removed by spraying the heated clean dry air on the front and back surfaces of the flat plate member from the inside of the housing toward the delivery port side. The present invention is characterized in that a moisture removing device is provided .
If the flat plate member is extremely disliked by molecular contaminants, it is more preferable to use the ultra low dew point air from which molecular contaminants of 5 ppb or less have been removed.

  Here, the ultra-low dew point air is provided with a plurality of disk-shaped members having high water absorption, such as silica gel, for example, and the plurality of stages of disk-shaped members are rotated from the blower while rotating the disk-shaped members. Passing through one section of the member, the dew point is lowered in sequence, and the disk-shaped member that has absorbed moisture is dried by a known ultra-low dew point air supply device in other sections in the rotational direction by a heater or the like. Obtainable.

  According to the above ultra-low dew point air supply device, contaminants such as organic substances contained in the air are also collected and removed when passing through disk-shaped members such as silica gel arranged in a plurality of stages. However, by installing a predetermined ULPA filter in the final stage, it is possible to obtain clean ultra-low dew point air from which molecular contaminants have been removed to 10 ppb or less.

  Next, the invention according to claim 2 is the invention according to claim 1, in which, when the pair of floating units is provided on the back surface side of the flat plate member in a direction orthogonal to the transport direction, In the case where a plurality of sets of the levitation units are provided between the conveyance means and the levitation unit in a direction orthogonal to the conveyance direction, the levitation unit is provided between the levitation unit and the levitation unit, respectively. A closing member that extends in the transport direction and improves the floating effect by the gas is interposed.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, an exhaust port for exhausting the ultra-low dew point air while holding the inside at a positive pressure is formed in the lower portion of the casing. It is characterized by that.

  Furthermore, the invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the flat plate is formed by irradiating the inside of the casing with soft X-rays toward the flat plate member. A soft X-ray static eliminator that neutralizes the shaped member is installed.

According to the transport apparatus for a flat plate member according to any one of claims 1 to 4 , an atmosphere of the ultra-low dew point air is formed inside the housing by the ultra-low dew point air supplied from the first clean dry air supply pipe. The flat member can be conveyed by the conveying means while being held in a non-contact manner by the ultra-low dew point air supplied from the second clean dry air supply pipe to the levitation unit. At this time, the ultra-low dew point air is harmful to the flat plate member during transportation because the atmospheric dew point is −100 ° C. or less and molecular contaminants are removed to 10 ppb or less. There is no risk of contamination such as moisture and organic matter. As a result, the production yield and quality of the flat member can be improved.

  In addition, since the ultra-low dew point air supplied to the inside of the casing and the floating unit has molecular contaminants removed to 10 ppb or less, the ultra-low dew point air obtained from one ultra-low dew point air supply device is used. Is supplied to the first and second ultra-low dew point air supply pipes, it is not necessary to provide a fan filter unit as in the conventional one for each conveying device, and the overall device can be simplified. it can.

  In this case, according to the invention described in claim 2, since the closing member is provided between the conveying means and the floating unit and between the floating unit, the gap between the back surface of the flat plate member and the closing plate is provided. A chamber-like space is formed. Thereby, since the ultra-low dew point air ejected from the levitation unit stays in the space, the floating effect by the ultra-low dew point air can be improved.

  According to the invention described in claim 3, since the exhaust port for exhausting the ultra-low dew point air is formed in the lower part of the casing while keeping the inside at a positive pressure, The generated molecules or molecular level contaminants can be discharged to the outside together with the ultra-low dew point air exhausted from the exhaust port. Therefore, the inside of the housing can always be kept in the atmosphere of the above-mentioned ultra-low dew point air, and the inside of the housing is always kept at a positive pressure, so that external air may flow backward from the exhaust port. Can be prevented.

  By the way, as described above, when the inside of the housing is held in an atmosphere of ultra-low dew point air, since the dew point is extremely low, static electricity is likely to be generated in the flat member that is the object to be conveyed. As a result, when the flat plate member comes into contact with another member, local discharge may occur and the device may be destroyed.

  In this regard, according to the invention described in claim 4, the soft X-ray static eliminator that neutralizes the flat plate member by irradiating the flat plate member with weak X-rays toward the flat plate member. Since this is installed, it is possible to prevent such adverse effects from occurring.

  Here, when performing ionization of the flat plate member, if an ionizer that generates ions between general electrodes is used, ozone is generated when the ions are generated, or particles that become pollutants are generated due to electrode wear. However, in the invention described in claim 4, the flat plate member is deliberately irradiated with weak X-rays directly to ionize the surrounding atmosphere, thereby eliminating static electricity from the flat plate member. Since the soft X-ray static eliminator is used, the above-described adverse effects can be prevented.

Furthermore, according to the invention described in any one of claims 1 to 4 , a moisture removing device is provided inside the housing, and the heated ultra-low dew point air is blown onto the flat plate member, whereby the flat plate member is Moisture at the molecular level adhering to the front and back surfaces can be removed by evaporation by the latent heat of the ultra-low dew point air.

  1 to 4 show an embodiment of a plate-shaped member conveying apparatus according to the present invention. This transfer device can be applied to the return of various flat members 1 that do not like the adhesion of contaminants such as moisture or molecular level organic matter to the surface of semiconductor wafers or glass substrates for flat display such as LCD, PDP, EL etc. In the figure, reference numeral 2 denotes a casing.

  The housing 2 is provided, for example, between the device 3 and the like in the pre-process and the device 4 and the like in the post-process, and the flat member 1 from the device 3 via the gate valve 5a at one end in the longitudinal direction. Is formed, and at the other end, a discharge port 6 is formed through which the flat plate member 1 is sent to the device 4 via a shutter 6a. And this housing | casing 2 is supported on the floor by the support | pillar 7. FIG.

  The inside of the housing 2 is partitioned into a chamber 2b and a transport path 2c by a partition plate 2a in which a number of punching holes are formed. In the transport path 2c, from the inlet 5 toward the outlet 6 A roller conveyor 8 (conveying means) is provided. This roller conveyor 8 conveys both ends of the plate-like member 1 carried in from the introduction port 5 to the delivery port 6 by a guided conveyance roller 8a, and a motor (not shown) serving as a drive source is It is installed outside the housing 2.

  And the floating unit 9 which supports the flat member 1 from the back surface side in a non-contact manner is arranged at two places with a predetermined interval between the conveying rollers 8a. Here, each levitation unit 9 has a porous ceramic plate 11 attached to the upper surface of a chamber 10 made of a metal casing having a rectangular shape in plan view, and an ultra-low dew point air supply pipe ( A second clean dry air supply pipe) 12 is connected. A plurality of independent floating units 9 are arranged so as to form two rows in parallel with the transport roller 8a.

On the other hand, between the conveyance roller 8a and the levitation unit 9 and between the levitation units 9, a blocking member 13 extending in a strip shape in the conveyance direction to improve the levitation effect by the ultra-low dew point air is interposed. It is disguised.
The roller conveyor 8 and the floating unit 9 are arranged on the same frame (not shown). In this embodiment, the heights of the inlet 5 and the outlet 6 are different. For this reason, the roller conveyor 8 and the floating unit 9 are provided with power provided between the housing 2 and the frame. By a lifting / lowering means such as a cylinder, it is provided so as to be movable up and down from a position indicated by a solid line to a position indicated by a dotted line.

A roller conveyor (conveying means) 14 that receives the flat plate-like member 1 from the roller conveyor 8 and sends it to the outlet 6 is provided in the vicinity of the outlet 6, and between the rollers 14 a of the roller conveyor 14, Similarly, the floating units 9 are arranged in two rows.
And along this roller conveyor 14, the soft X-ray static elimination apparatus 15 and the water | moisture-content removal apparatus 16 are arrange | positioned sequentially. The soft X-ray neutralization device 15 is disposed at the upper and lower portions of the base end portion of the roller conveyor 14 so as to irradiate the front and back surfaces of the transported flat plate member 1 with weak X-rays.

  Further, as shown in FIG. 3, the moisture removing device 16 includes a pair of rectifying plates 17 disposed in the vicinity of the front and back surfaces of the flat plate member 1 along the roller conveyor 14, and a flat plate from the base end side of the roller conveyor 14. It is comprised from the air knife 18 with a heater which blows the ultra-low dew point air heated at about 60 degreeC toward the front-and-back surface of the shaped member 1, and the baffle plate 17. As shown in FIG.

In this transport apparatus, an ultra-low dew point air supply pipe (first clean dry air supply pipe) 19 is connected to the ceiling of the housing 2 to fill the interior with ultra-low dew point air. On the other hand, a slit-like exhaust port 20 for exhausting ultra-low dew point air while holding the inside of the housing 2 at a positive pressure is formed at the bottom of the housing 2.
Note that the inner wall of the housing 2 and the constituent members of the devices inside are all made of a material that is well drained and hardly generates organic matter from itself.

  According to the transport device for the flat plate member 1 having the above-described configuration, the ultra-low dew point air is introduced into the chamber 2 b in the housing 2 by the ultra-low dew point air supplied from the ultra-low dew point air supply pipe 19. Then, the ultra-low dew point air in the chamber 2b diffuses and flows into the transport path 2c from a number of punching holes formed in the partition plate 2a. Thereby, the inside of the housing | casing 2 is hold | maintained in the atmosphere of ultra-low dew point air.

  In this state, the gate valve 5a of the introduction port 5 is opened, and the flat plate member 1 is carried into the housing 2 from the device 3 in the previous process. In parallel with this, an air film of 0.1 to 0.2 mm is formed between the flat plate member 1 and the ultra low dew point air supplied from the ultra low dew point air supply pipe 12 to the floating unit 9. By doing this, the flat plate-like member 1 is transferred onto the roller conveyor 8 while being supported from the back side in a non-contact manner.

  Next, the roller conveyor 8 and the floating unit 9 are integrally raised to the same level position as the roller conveyor 14 indicated by a dotted line in the drawing, and further conveyed to the roller conveyor 14 side. At this time, the soft X-ray neutralizing device 15 directly irradiates the front and back surfaces of the flat plate member 1 with weak X-rays to ionize the surrounding atmosphere, thereby neutralizing the flat plate member 1.

Next, when the flat plate member 1 passes between the current plates 17, ultra-low dew point air heated to 55 ° C. or more, preferably about 60 ° C., is applied to the front and back surfaces of the flat plate member 1 from the air knife 18 with a heater. Spray each one. Thereby, the moisture at the molecular level adhering to the front and back surfaces of the flat plate member 1 in the apparatus 3 or the like in the previous process is removed by evaporation by the latent heat of the ultra low dew point air.
The flat plate-like member 1 that has been subjected to static elimination and moisture removal in this way is discharged to the apparatus 4 in the subsequent process by opening the shutter 6a of the delivery port 6.

  As described above, according to the transport device for the flat plate member 1, the inside of the housing 2 is held in an atmosphere of ultra-low dew point air by the ultra-low dew point air supplied from the ultra-low dew point air supply pipe 19. In addition, the flat member 1 can be conveyed by the conveying means while being supported in a non-contact manner by the ultra low dew point air supplied from the supply pipe 12 of the ultra low dew point air to the levitation unit 9. There is no risk of adhering contaminants such as moisture and organic matter.

  Further, since the closing member 13 is provided between the conveying rollers 8 a and 14 a and the floating unit 9 and between the floating units 9, a chamber-like space is provided between the back surface of the flat plate member 1 and the closing plate 13. Thus, since the ultra-low dew point air ejected from the levitation unit 9 stays in the space, the floating effect of the flat member 1 by the ultra-low dew point air can be improved.

  In addition, since an exhaust port 20 for exhausting ultra-low dew point air while holding the inside at a positive pressure is formed in the lower portion of the housing 2, molecules or molecular level contaminants generated from the members in the housing 2 are formed. Can be discharged together with the ultra-low dew point air exhausted from the exhaust port 20. For this reason, the inside of the housing 2 can always be kept in an atmosphere of ultra-low dew point air, and the inside of the housing 2 is always kept at a positive pressure, so that external air flows backward from the exhaust port 20. It can also be prevented.

  Furthermore, as a result of holding the inside of the housing 2 in an atmosphere of ultra-low dew point air, static electricity is likely to be generated in the flat plate member 1, but the surface of the flat plate member 1 is formed at the base end portion of the roller conveyor 14. Since the soft X-ray neutralizing device 15 that removes static electricity from the flat plate member 1 by irradiating the back surface with soft X-rays is installed, there is no possibility that a negative effect due to charging of the flat plate member 1 will occur.

  In the above embodiment, only the case where the roller conveyors 8 and 14 are used as the conveying means has been described. However, the present invention is not limited to this, and the conveying is performed while supporting both side portions of the flat plate member 1. It is also possible to apply other conveying means as long as it is possible to do so. Moreover, as long as the inside of the housing | casing 2 can be filled with ultra-low dew point air, the position of the supply pipe | tube 19 is not restricted to the ceiling part of the housing | casing 2, You may provide in a side wall.

It is a cross-sectional view which shows one Embodiment of the conveying apparatus of the flat member which concerns on this invention. It is a longitudinal cross-sectional view which shows the said embodiment. FIG. 3 is a plan view of FIG. 2. It is the elements on larger scale of the moisture removal apparatus of FIG. It is a cross-sectional view which shows the conveying apparatus of the conventional flat member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flat member 2 Case 5 Inlet 6 Outlet 8, 14 Roller conveyor (conveyance means)
9 Levitation unit 12 Ultra-low dew point air supply pipe (first clean dry air supply pipe)
13 Blocking plate 15 Soft X-ray static eliminator 19 Supply pipe for ultra-low dew point air (second clean dry air supply pipe)
20 Exhaust port

Claims (4)

A housing having an inlet and a delivery port for the flat plate member, and a conveying means disposed in the housing and carrying both sides of the flat plate member from the introduction port toward the delivery port; In the flat plate member conveying apparatus, which is provided in parallel with the conveying means on the back surface side of the flat plate member, and includes a levitation unit that levitates the flat plate member by the jetted gas.
The housing is provided with a first clean dry air supply pipe filled with clean dry air having an atmospheric pressure dew point of −100 ° C. or less in which molecular contaminants have been removed to 10 ppb or less. A second clean dry air supply pipe for supplying the clean dry air as a floating gas for the flat plate member is provided , and the heated clean dry air is supplied from the inside of the housing to the outlet side. Toward this, a flat plate member conveying apparatus is provided, which is provided with a water removing device that removes water adhering to the surface of the flat plate member by spraying the front and back surfaces of the flat plate member.   In the case where the back surface side of the flat plate member has a set of the levitation unit in a direction orthogonal to the conveyance direction, a plurality of levitation units are provided between the conveyance means and the levitation unit in the direction orthogonal to the conveyance direction. In the case of having a pair of the levitation units, a blocking member extending between the conveyance means and the levitation unit and between the levitation units and extending in the conveyance direction and improving the levitation effect by the gas is interposed. The flat plate-shaped member conveying device according to claim 1.   3. The flat plate member conveying apparatus according to claim 1 or 2, wherein an exhaust port for exhausting the clean dry air is formed at a lower portion of the housing while keeping the inside at a positive pressure.   2. A soft X-ray static eliminator for removing static electricity from the flat plate member by irradiating the flat plate member with soft X-rays inside the casing. 4. The flat plate member conveying apparatus according to any one of 3 above.

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