Abstract:
A non-contacting conveyance equipment comprises: a body having an end face that opposes an object to be conveyed, and a concave opening formed in the end face and surrounded by a cylindrical inner side wall; and a fluid passageway having a plurality of pairs of spouts to introduce fluid into an inner space of the concave opening in a circumferential direction of the cylindrical inner side wall so as to cause a swirl of fluid within the concave opening, each of the plurality of pairs of spouts being formed on the cylindrical inner side wall symmetrically to a central axis of the concave opening. A plurality of the non-contacting conveyance equipments may be provided on a base.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to non-contacting conveyance equipment used in rotation etc. 
   2. Description of the Related Art 
   In recent years, as the use of integrated circuit cards, smart cards, etc., has increased, and the uses and types of such products have become more diverse, wafers have become thin, and the diameter of wafers has increased. Wafers 0.5 mm thick and 10 inches in diameter have been developed. Such thin and large wafers curve or crack easily. 
   Thus it is difficult to avoid cracking a wafer when conveying it to be processed or moving it within a processing stage for manufacturing integrated circuits. That is, the mechanical integrity of a wafer decreases as the diameter of the wafer increases, or as the thickness of the wafer decreases. For this reason, non-contacting conveyance equipment is proposed. Non-contacting conveyance equipment holds and conveys a wafer by non-contacting means using air, nitrogen gas, and the like, and such means are already in practical use. 
   For example, in JP 11-254369, air is introduced through an air inlet into a chamber. Within the chamber, the air flows about a rotational flow generating plate and is then deployed to the inside of a bell mouth. The air enters the bell mouth while turning, and is directed out of the bell mouth over a flat surface at the parameter of the bell mouth. An object to be carried rests within the bell mouth. 
   One problem associated with the device disclosed in JP11-254369 is that, because air is introduced from an inlet above the bell mouth, a large amount of air is necessary. In addition to consuming excess energy, increased air flow can be detrimental in a semiconductor clean room. That is, currents of air within the clean room can stir up dust and other debris. Dust and debris can cause defects in the circuits printed on the semiconductor wafers. 
   Moreover, with the non-contacting conveyance equipment proposed in JP11-254369, the power of attracting and holding a conveyed object by causing a fluid to swirl can be improved because the feeding mouth, revolution room, and bell mouth of air allow free passage for the conveyed object, are complicated in structure and the equipment is costly to manufacture. 
   Moreover, since the equipment of JP11-254369 is structurally complicated, miniaturization is difficult, the action range of the equipment is limited, and the equipment is problematically inflexible. 
   Furthermore, owing to the complicated structure of a method using air, passage resistance becomes great. Therefore, in order to maintain sufficient attraction power, a lot of air needs to be deployed, thereby decreasing energy efficiency. Moreover, when a lot of air is circulated in a clean room, displaced dust becomes a problem. 
   SUMMARY OF THE INVENTION 
   The present invention is proposed in view of the above. The equipment of the present invention can be manufactured at a lower cost, can be easily miniaturized, and has an extended scope of use. Furthermore, the non-contacting conveyance equipment of the present invention can save energy. 
   The above-mentioned objectives can be attained by a non-contacting conveyance equipment comprising: a body having an end face that opposes an object to be conveyed, and a concave opening formed in the end face and surrounded by a cylindrical inner side wall; and a fluid passageway having a plurality of pairs of spouts to introduce fluid into an inner space of the concave opening in a circumferential direction of the cylindrical inner side wall so as to cause a swirl of fluid within the concave opening, each of the plurality of pairs of spouts being formed on the cylindrical inner side wall symmetrically to a central axis of the concave opening. 
   A plurality of the non-contacting conveyance equipments may be provided on a base. In this case fluid may swirl clockwise in at lease one of the plurality of fluid swirl formation objects, and fluid may swirl counterclockwise in at least one of the plurality of fluid swirl formation objects. The base may be surrounded with a peripheral edge to prevent fluid away from the base. 
   The base may have a center with a center swirl formation object formed substantially at the center of a base and a plurality of fluid swirl formation objects arranged around the center swirl formation object. The center swirl formation object is similar to the fluid swirl formation objects except that an inner wall may be formed within the concave opening of the center swirl formation object so as to form a channel between an outer surface of the inner wall and the inner peripheral surface of the concave opening. 
   The fluid supplied through the spout may be ionized. In addition, or as an alternative to ionization, the fluid may be air, which is vibrated at an ultrasonic frequency. 
   Centering protrusions may be radially displaced from a center of the non-contacting conveyance equipment. A centering mechanism may vary the radial distance of the centering protrusions from the center of the non-contacting conveyance equipment. 
   In this invention, a spout faces the inside of a concave opening to supply fluid to an inner peripheral surface. According to one aspect of the invention, this configuration allows objects to be conveyed using a smaller quantity of air than was previously possible. Accordingly, energy consumption is reduced. Perhaps more importantly, this aspect of the invention minimizes the air currents generated while conveying objects. If used in a semiconductor clean room, less dust and debris may be stirred up by the non-contacting conveyance equipment. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be readily understood by reference to the following description of embodiments described by way of example only, with reference to the accompanying drawings in which like reference characters represent like elements, wherein: 
       FIGS. 1A and 1B  are perspective views of the first embodiment of non-contacting conveyance equipment, where  FIG. 1A  is a view from a slanting lower point, and  FIG. 1B  is a view from a slanting upper point. 
       FIGS. 2A and 2B  are cross sectional views of the non-contacting conveyance equipment shown in  FIG. 1A , where  FIG. 2A  is a view taken through the I-I line of  FIG. 1A , and  FIG. 1B  is a view taken through the II-II line of  FIG. 1A . 
       FIGS. 3A and 3B  are perspective views of the second embodiment of non-contacting conveyance equipment, where  FIG. 2A  is a view from a slanting lower point, and  FIG. 2B  is a view from a slanting upper point. 
       FIGS. 4A and 4B  are views of the non-contacting conveyance equipment shown in  FIGS. 3A and 3B , where  FIG. 4A  is a bottom view of  FIG. 3A , and  FIG. 4B  is a view taken through the III-III line of  FIG. 3B . 
       FIG. 5  is a cross sectional side view of the third embodiment of non-contacting conveyance equipment. 
       FIG. 6  is a top view of the third embodiment of non-contacting conveyance equipment. 
       FIG. 7  is an action diagram of the centering mechanism, viewed through the IV-IV line of  FIG. 5 . 
       FIG. 8  is a perspective view, from a slanting upper point, of the fourth embodiment of non-contacting conveyance equipment. 
       FIGS. 9A and 9B  are views of the non-contacting conveyance equipment shown in  FIG. 8 , where  FIG. 9A  is a top view, and  FIG. 9B  is a view taken through the V-V line of  FIG. 9A . 
       FIG. 10  is a perspective view of the fifth embodiment of non-contacting conveyance equipment, shown individually with solid lines, and shown with dotted lines as inserted into a wafer cassette. 
       FIG. 11  is a top view of the non-contacting conveyance equipment shown in  FIG. 10 , inserted in the wafer cassette. 
       FIG. 12  is a horizontal sectional view of the non-contacting conveyance equipment shown in  FIGS. 10 and 11 . 
       FIG. 13  is a perspective view of the sixth embodiment of non-contacting conveyance equipment. 
       FIG. 14  is a partial front sectional view of the seventh embodiment of non-contacting conveyance equipment. 
       FIG. 15  is a partial front sectional view of the eighth embodiment of the non-contacting conveyance equipment. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention will now be described with reference to embodiments and examples, although the invention is not limited to these. 
     FIGS. 1A and 1B  are perspective views of the first embodiment of non-contacting conveyance equipment, where  FIG. 1A  is a view from a slanting lower point, and  FIG. 1B  is a view from a slanting upper point.  FIGS. 2A and 2B  are cross sectional views of the non-contacting conveyance equipment shown in  FIG. 1A , where  FIG. 2A  is a view taken through the I-I line of  FIG. 1A , and  FIG. 1B  is a view taken through the II-II line of  FIG. 1A . In these views, the non-contacting conveyance equipment  1  of the present invention is equipment which holds and conveys an object (here wafer  9 ) by non-contacting. Moreover, this equipment is constructed using a pillar-shaped fluid swirl formation object  2 . The non-contacting conveyance equipment  1  of the present invention is equipped inside with the circumference-like concave part  3 . In equipment  1 , flat-end-face  2   b  is provided at the opening side of concave part  3 , and supports the object non-contactingly. A fluid passage  5  supplies fluid to a spout  4 , which faces the inside of concave part  3  and breathes the fluid out along a direction tangential to an inner circumference of concave part  3  and into concave part  3 . 
   A fluid introduction mouth  6  is prepared in a closed-face  2   a  of fluid swirl formation object  2  by drilling perpendicular to closed-face  2   a  until reaching fluid passage  5 , which is drilled horizontally to reach spout  4 , which faces the inside of concave part  3 . That is, fluid passage  5  provides free passage from fluid introduction mouth  6  to spout  4 , and causes supply fluid to breathe out along the direction tangential to the inner circumference of concave part  3  and into concave part  3  from spout  4 . By this arrangement, fluid is supplied such that a fluid swirl occurs inside the concave part  3 . 
   Fluid introduction mouth  6 , fluid passage  5 , and a set of two spouts  4  are formed, and the fluid (here air) which blows off from the set of two spouts  4  is breathed out in the same direction in a circumferential direction, and thereby the spouts mutually create a fluid swirl of slight strength. 
   Moreover, slope  3   a  is formed by chamfering and the diameter of the opening edge of the concave part  3  is expanded in the shape of a trumpet. Therefore, the fluid swirl generated in concave part  3  can flow swiftly out of concave part  3  via this slope  3   a.    
   In the non-contacting conveyance equipment  1  of the above-mentioned construction, if air is supplied to fluid introduction mouth  6  from air supply equipment (not shown), the air will be blown into concave part  3  from spout  4  through fluid passage  5 . The air becomes a fluid swirl, and is resupplied in the internal space of concave part  3 . The resupplied swirling air then flows out of concave part  3 . If wafer  9  is arranged in a position counter to flat-end-face  2   b  of fluid swirl formation object  2 , then at the time of the outflow, since air will flow out at high-speed along with flat-end-face  2   b , negative pressure occurs between flat-end-face  2   b  and wafer  9 . Therefore, wafer  9  is pushed by surrounding atmospheric pressure, and is attracted to flat-end-face  2   b  side. The air between flat-end-face  2   b  and wafer  9  is restored, and wafer  9  comes to be held in balance counter to flat-end face  2   b  and by non-contacting. 
   Thus, in the first embodiment of the present invention, wafer  9  is held with fluid swirl formation object  2 , simply formed with concave part  3 , flat-face  2   b , and fluid passage  5 . The equipment can be easily constructed, and the cost of manufacturing the equipment can be greatly reduced. 
   Moreover, since the equipment can be easily constructed, it can also be easily miniaturized. When miniaturized, the equipment can be inserted in previously unconventional spaces, its range of action may be extended, and its conveyance movement in a narrow domain within the same process and processing equipment can be performed more freely. 
   Moreover, since the fluid is resupplied in accordance with an interior that allows the fluid to be blown into concave part  3 , a fluid swirl is created; the fluid swirls smoothly, and with reduced passage resistance. Therefore, energy efficiency is raised and energy use is curtailed. 
   Furthermore, the equipment blows fluid off in a circumferential direction in the concave part  3 . Since this generates a fluid swirl, the attracting power of the negative pressure between flat-face  2   b  and the wafer  9  is markedly improved as compared with the conventional method, and becomes powerful. 
   In addition, although the above embodiment describes two sets of devices (a fluid introduction mouth  6 , a fluid passage  5 , and a spout  4 ), one such set is sufficient, and three or more sets may also be used. 
   Moreover, although fluid introduction mouth  6  is provided for each set of devices, one fluid introduction mouth  6  may feed plural elements. That is, one fluid introduction mouth may branch off to supply a plurality of fluid passages  5  and plural spouts  4 . 
   Furthermore, although fluid passage  5  was formed in the combination of a vertical course and a horizontal course, it is not limited to such courses. It is only necessary to form fluid passage  5  so that air may be spouted in a circumferential direction in concave part  3  from fluid introduction mouth  6 . 
   Next, a second embodiment of the non-contacting conveyance equipment of the present invention is explained, with reference to  FIGS. 3 and 4 . Some of the equipment of the first embodiment, described above, is used in this second embodiment, the same reference numerals are given to the same elements, and duplicate explanations are omitted. 
     FIGS. 3A and 3B  are perspective views of the second embodiment of non-contacting conveyance equipment, where  FIG. 2A  is a view from a slanting lower point, and  FIG. 2B  is a view from a slanting upper point.  FIGS. 4A and 4B  are views of the non-contacting conveyance equipment shown in  FIGS. 3A and 3B , where  FIG. 4A  is a bottom view of  FIG. 3A , and  FIG. 4B  is a view taken through the III-III line of  FIG. 3B . 
   Two or more fluid swirl formation objects  2 , as explained in the first embodiment, are used in the non-contacting conveyance equipment  11  of the second embodiment. Non-contacting conveyance equipment  11  is equipped with a support object  12  comprised of a peripheral surface  14  installed in a base  13  and at the perimeter of base  13 . Four fluid swirl formation objects  2  are attached in base  13  of support object  12 . 
   Each of the four fluid swirl formation objects  2  is attached in the inside (base field) of the base  13  by their closed-face sides  2   a . Moreover, they are supported so that their flat-end-faces  2   b  mutually form a same side. The height of peripheral surface  14  is adjusted so that its end face  140  also forms the side mutually formed by flat-end-faces  2   b . Furthermore, a chamber fin  141  is formed in the shape of two steps in a part of the inner periphery of an end face  140  of peripheral surface  14 . 
   Corresponding to each of the fluid swirl formation objects  2 , a fluid supply mouth  15  is formed in an external surface  130  of the base  13 . A base passageway  131 , to which each of the fluid supply mouths  15  and two fluid introduction mouths  6  of the corresponding fluid swirl formation object  2  is connected is branched and formed in the wall inside of the body part of base  13  from fluid supply mouth  15  ( FIG. 4  ( b )). 
   A supply mouth  15  in base  13  connects to base passageway  131  that is formed in the wall of base  13 , and branches out to connect to fluid introduction mouths  6 . 
   Five fluid outlets  16 , other than the four above-mentioned fluid supply mouths  15 , are formed in external surface  130  of base  13 . Discharge passages  132 , which lead to each of fluid outlets  16 , are installed through the wall inside of the body part of base  13 , and connect fluid outlets  16  to support object  12 . 
   Furthermore, attachment piece  171  is protruded on four places at predetermined intervals at peripheral surface  14  of support object  12 . Nearly cylindrical lateral movement prevention guides  172  are installed in an attachment piece  171 . The end sides of these lateral movement prevention guides  172  are projected to the plane mutually formed by end face  140  of peripheral surface  14 , and each flat-end-face  2   b.    
   In the non-contacting conveyance equipment  11  of the above-mentioned construction, if the air from air supply equipment (not shown) is sent to fluid supply mouth  15 , the air will be blown into concave part  3  from spout  4  through base passageway  131 , fluid introduction mouth  6 , and fluid passage  5 . The air becomes a fluid swirl, and is resupplied in the internal space of concave part  3 , and the air then flows out of concave part  3 . When the fluid swirls hold wafer  9  by non-contacting, the rotational direction of the fluid swirls are beforehand mutually adjusted so that wafer  9  does not rotate. For example, as shown in  FIG. 4A , by arrangement of the spouts  4 , the fluid swirls clockwise in two of the fluid swirl formation objects  2 , and counterclockwise in the other two fluid swirl formation objects  2 . 
   As in the case of the above-mentioned first embodiment, if wafer  9  is arranged in a position counter to flat-faces  2   b  of fluid swirl formation objects  2  at the time of the outflow of each fluid swirl, wafer  9  will be held by non-contacting in response to the attracting power of the negative pressure created by the restitution of the air flow where flat-face  2   b  is countered. Movement of wafer  9  is also guided and prevented by lateral movement prevention guides  172 , which are particularly useful if wafer  9  moves when support object  12  is moved during manufacturing. That is, non-contacting conveyance equipment  11  holds and conveys wafer  9  by non-contacting. 
   Airflow passing though flat-end-face  2   b  from concave part  3   b  goes into the internal space of support object  12 . It passes along discharge passage  132  and fluid outlet  16 , after which it is compulsorily discharged via the exhaust (not shown). 
   Moreover, the flow that reaches peripheral surface  14  is disturbed and resisted by chamber fin  141  of peripheral surface  14 . For this reason, less air escapes over end face  140  of the peripheral surface  14 , and outflow is decreased. Therefore, most air flow stays in the internal space and discharges by passing along discharge passage  132  and out of fluid outlets  16 . 
   Moreover, lateral movement prevention guides  172  are formed outside of peripheral surface  14 . If wafer  9  held by non-contacting tends to move or deviate horizontally, this movement is prevented, and wafer  9  is stabilized during conveyance by lateral movement prevention guides  172 . 
     FIG. 3  shows the second embodiment of the present invention, which may be constructed using the easily constructed fluid swirl formation objects  2  of the first above-mentioned embodiment. 
   For this reason, the embodiment also may realize the benefits of miniaturization and energy savings. Moreover, since it is made to attract wafer  9  by the fluid swirl formed in concave part  3 , the attracting power can be made markedly improved. 
   Moreover, since it may be caused to generate the fluid swirls in four places, the whole of wafer  9  may be more powerfully attracted. Therefore, it becomes possible to correct curvature over the whole wafer  9 , and the curvature reform power also becomes powerful. Consequently, when wafer  9  is large, and even in the case where it is curved, the wafer can be reliably held by non-contacting, and where conveyance is also stabilized, it can carry wafer  9  with greater certainty. 
   Moreover, each fluid swirl formation object  2  has a simple construction that blows air into concave part  3  and forms a fluid swirl directly. For this reason, a stable fluid swirl with non-contacting maintenance power is used. Four fluid swirl formation objects  2  become uniform with each other, and non-contacting maintenance of wafer  9 , which formerly tended to become a little unstable, can be performed with sufficient stability. 
   Furthermore, due to the power of non-contacting maintenance, if the whole non-contacting conveyance equipment  11  reverses direction, a reliable state of maintenance is attained. Moreover, wafer  9  can be reversed with the non-contacting conveyance equipment and can be conveyed to a subsequent processing stage. 
   In addition, although the construction of this second embodiment establishes four fluid swirl formation objects  2 , it is not so limited, and arbitrary numbers of fluid swirl formation objects  2  may be used. 
   Moreover, although chamber fin  141  of peripheral surface  14  was made into the shape of stairs, it is only necessary that the structure increase air resistance. A slot form, for example, also works to increase air resistance. 
   Furthermore, fluid supply mouth  15  and fluid outlets  16  may be prepared in arbitrary numbers. However, at least three lateral movement prevention guides  172  need to be prepared. 
   Next, the third embodiment of the non-contacting conveyance equipment of the present invention is explained using  FIG. 5 ,  FIG. 6 , and  FIG. 7 . 
     FIG. 5  is a cross sectional side view of the third embodiment of non-contacting conveyance equipment. 
     FIG. 6  is a top view of the third embodiment of non-contacting conveyance equipment. 
     FIG. 7  is an action diagram of the centering mechanism, viewed through the IV-IV line of  FIG. 5 . 
   The non-contacting conveyance equipment  21  of this third embodiment differs from the above-mentioned non-contacting conveyance equipment  11  of the second embodiment in that it is formed with a centering mechanism  200 , for positioning a wafer  9 , and for preventing lateral movement of wafer  9  which is held by non-contacting. 
   Centering mechanism  200  is equipped with a rotary actuator  203  fixed on a base board  202  supported with a support  201  set up on an external surface  130  of base  13 . Moreover, centering mechanism  200  is equipped with link arms  205 , prepared toward the quarters of a perimeter edge of a flange  204 , which is attached to a shaft (not shown) of rotary actuator  203 . Each of the link arms  205  has an uneven, long, and slender board material, one end of which is installed in the perimeter edge of flange  204 , and other end of which is level. Moreover, a slot  206  for a guide is established in an attachment piece  209 , which protrudes in a direction away from external surface  130 . A bolt is inserted in slot  206 , and attachment piece  209  is established in the other end of link arm  205 . A centering guide (arm for centering)  207  can be screwed on and installed in the bolt, and centering guide  207  can be slid along slot  206  for a guide. 
   Centering mechanism  200  of non-contacting conveyance equipment  21 , constructed as above, operates as follows. First, air is sent into an air drive insertion mouth  208  of rotary actuator  203 , setting into operation rotary actuator  203 . According to the operation, flange  204  rotates through a predetermined angle, in the direction shown by the arrow  22  in  FIG. 7(   a ) of actuator  203 , from the state of  FIG. 7(   a ), to the state of  FIG. 7(   b ); each link arm  205  moves according to the rotation. At this time, centering guide  207 , installed at the other end of link arm  205 , is guided in slot  206  as a guide of the attachment piece  209 , and performs straight movement. Link arms  205  move only a predetermined distance in the direction of the center of base  13 , and then stop. Wafer  9 , currently held by non-contacting conveyance equipment  21 , is regulated at the four quarters of the perimeter by lateral movement in a direction of the center of centering guide  207 . By such movement, the center of wafer  9  comes to be positioned in alignment with the center of the internal space of support object  12 . On the other hand, regulation of wafer  9  may be cancelled by rotating flange  204  in an opposite direction to that shown by arrow  22 . Thereby, centering guide  207  moves in the direction that separates from the center of base  13 , and wafer  9  held by non-contacting, is free to move laterally. 
   According to the operation of rotary actuator  203 , centering guide  207  isolates or approaches only the same distance to peripheral surface  14 , respectively. And while holding wafer  9  by non-contacting on the inner side, wafer  9  is positioned with high precision. Therefore, when conveying wafer  9  and arranging it in a predetermined position, it may be arranged with high precision. Therefore, wafer  9  may be processed smoothly and accurately. 
   Next, the fourth embodiment of the non-contacting conveyance equipment of the present invention is explained with reference to  FIGS. 8 and 9 . 
     FIG. 8  is a perspective view, from a slanting upper point, of the fourth embodiment of non-contacting conveyance equipment.  FIGS. 9A and 9B  are views of the non-contacting conveyance equipment shown in  FIG. 8 , where  FIG. 9A  is a top view, and  FIG. 9B  is a view taken through the V-V line of a  FIG. 9A . 
   In the non-contacting conveyance equipment  31  of the fourth embodiment, a fluid swirl formation object  32  at the center of equipment  31 , and the fluid swirl formation objects  2  at the circumference of the equipment  31  are constructed differently. Two fluid swirl formation objects  2 , arranged at the circumference of the equipment  31 , have the same construction as used in the first, second, and third embodiments. However, the fluid swirl formation object  32  arranged at the center of equipment  31  has the following construction. 
   Inside concave part  33  of fluid swirl object  32 , a peripheral-wall  33   a  is prepared, forming a swirl passage  38 , and a central hole  321 . Moreover, a fluid introduction mouth  36  is formed so that the perimeter side of the fluid swirl formation object  32  may be faced. A fluid passage  35  is horizontally drilled in a thick part of the inside of fluid swirl formation object  32 , from fluid introduction mouth  36 , and reaching spout  34  so that fluid swirl passage  38  is accessed. Air is breathed out, along the direction of a circumference of fluid passage  38 , into fluid swirl passage  38  from spout  34 , and, swirling around at and in fluid swirl passage  38 , the air serves as a fluid swirl. Fluid introduction mouth  36 , fluid passage  35 , and a set of two spouts  34  are formed. The air which blows off from each of the spouts  34  is breathed out in a circumferential direction, and mutually forms a fluid swirl of slight strength. 
   Moreover, as shown in a  FIG. 9  ( b ), fluid supply mouths  15  prepared in base  13  correspondingly join to the two fluid introduction mouths  36  of fluid swirl formation object  32  located at the center. Moreover, one piece is prepared at a time in each of the fluid swirl formation objects  2  located towards the circumference as in the second embodiment. 
   Each of the fluid swirl formation objects  2  located towards the circumference is constructed so that their swirls rotate in mutually reverse directions. 
   In this fourth embodiment, wafer  9  is held by non-contacting by the fluid swirl generated with fluid swirl formation objects  2  and  32 . This effects the same peculiar action demonstrated in the embodiments above. 
   That is, since fluid swirl passage  38  was established in the center of fluid swirl formation object  32 , the air which flows in fluid swirl passage  38  serves as a high-speed fluid swirl. Therefore, the fluid swirls being further resupplied, wafer  9 , currently held by non-contacting, is rotated with strengthened torque and wafer  9  rotates at high speed, to an extent not possible with a conventional non-contacting equipment. Equipment that carries out centrifugal separation and dries moisture adhered to wafer  9  during a washing process, can be constructed using fluid swirl formation object  32  to rotate wafer  9  at high speed. Moreover, it can also serve as a washing machine that, by non-contacting, dries off and washes foreign substances adhering to wafer  9 , without cracking wafer  9 . Moreover, the rotation drive when detecting the orientation flat and V notch of the wafer, the rotation drive at the time of appearance inspection of the wafer, the rotation drive at the time of wafer etching, etc., can use it. 
   The direction and intensity of the fluid swirl in the fluid swirl formation objects  2  are both controlled by the amount of supplied air. By such control, the high-speed rotation of wafer  9  by central fluid swirl formation object  32  is controllable at a proper rotation speed. Therefore, equipment  16  of the fourth embodiment can be appropriately used as a drier or as a washing machine. 
   Next, the fifth embodiment of the non-contacting conveyance equipment of the present invention is explained using  FIGS. 10 ,  11 , and  12 . 
     FIG. 10  is a perspective view of the fifth embodiment of non-contacting conveyance equipment, shown individually with solid lines, and shown with dotted lines where inserted into a wafer cassette.  FIG. 11  is a top view of the non-contacting conveyance equipment, shown in  FIG. 10 , inserted in the wafer cassette.  FIG. 12  is a horizontal sectional view of the non-contacting conveyance equipment shown in  FIGS. 10 and 11 . Circumference-like concave parts  43  are inside the board-like base  42 , which has a flat side  42   b , in which non-contacting conveyance equipment  41  counters wafer  9  in these figures. Fluid passages  45 , which make air breathe out along the direction of an inner circumference of the concave parts  43 , are formed into concave parts  43 , and consist of spouts  44  which face the insides of concave parts  43 . 
   The board-like base  42  consists of a base part  421  and two arm parts  422 , which branch from base part  421 , forming two prongs of a fork. A grasping part  49 , for enabling movement of the base  42 , adheres to the end side of base  421 . Concave parts  43  are located in a line along each of arm parts  422 ; three concave parts  43  to one arm part  422 . Moreover, an E-like movement prevention guide  48  is formed in one of the concave parts  43  to an arm part  422 . 
   As shown in  FIG. 12 , the fluid passages, installed in the two arm parts  422 , pass to two fluid introduction mouths  46 , which open to the side of grasping part  49 . Fluid passages  45  branch to spouts  44  which attend concave parts  43 . 
   In the non-contacting conveyance equipment  41  of the above-mentioned construction, if the air from air supply equipment (not shown) is sent to fluid introduction mouth  46 , the air will be blown into each of concave parts  43  from spouts  44  through fluid passages  45 . The air becomes a fluid swirl, and is resupplied in the internal spaces of concave parts  43 , after which the air flows out of concave parts  43 . The direction of each of the fluid swirls, holding the wafer  9  by non-contacting, may be mutually adjusted beforehand so that wafer  9  does not rotate. For example, as shown in  FIG. 12 , the three concave parts  43  of one arm part  422  are adjusted to swirl clockwise by changing the arrangement of spouts  44 , at three concave parts  43 ; the fluid swirls of the other arm part  422  are similarly arranged to swirl counterclockwise. 
   As is the case with each of the above-mentioned embodiments, when wafer  9  is arranged in a position counter to the flat side  42   b  of base  42 , the outflow of each fluid swirl holds wafer  9  in balance by the negative pressure created by the outflow of the fluid swirls, and by resupplying of the air flow by non-contacting, where flat side  42   b  is counter to the wafer. If grasping part  49  is held in the state of maintenance, and board-like base  42  is moved, wafer  9  will move with it, and wafer  9  will be guided by movement prevention guide  48 . That is, non-contacting conveyance equipment  41  holds and conveys wafer  9  by non-contacting. 
   Since base  42  of this non-contacting conveyance equipment  41  is thinly constructed in the shape of a board, as shown in  FIGS. 10 and 11 , the board may be inserted into a narrow opening in a stack of wafers  9 , which adjoin each other by the upper and lower sides, and which are held on shelves  81  of a wafer cassette  80 . 
   Thus, in the fifth embodiment of the present invention, since it is made to attract wafer  9  by the fluid swirls formed in each of concave parts  43 , as in the case of each of the above-mentioned embodiments, the power of attraction can be made powerful with a board-like base  42  holding the wafer fully secured. Therefore, non-contacting conveyance equipment  41  can be constructed in the shape of a board, capable of smoothly and freely accessing and retrieving wafers stacked in a wafer cassette  80 , which is conventionally difficult to access. Moreover, in a case where wafer cassette  80  is contained and loaded with the wafer, it can timely carry a wafer to a desired position. That is, taking a wafer from wafer cassette  80  and carrying in to wafer cassette  80  can be performed freely, thereby sharply increasing the working efficiency. 
   Furthermore, since the fluid swirls are formed at two or more places, and since the non-contacting maintenance power is powerful, even a wafer  9  that has curvature may be held in a state of non-contacting maintenance where its curvature is corrected. Moreover, even if the whole non-contacting conveyance equipment  41  is reversed, the maintenance state can be maintained, wafer  9  is also reversed, and wafer cassette  80  can also be loaded, reversed, and conveyed to a subsequent processing stage. 
   In addition, although in the explanation above board-like base  42  was constructed with two forks and so considered, and although the construction put three concave parts  43  in order at a time, these modes of construction are arbitrary and should be constructed depending on their use. For example, one arm instead of two forks may be considered, and an arm may be constructed with only one concave part  43 . Moreover, grasping part  49 , although formed in this embodiment, is formed only if needed. 
   Next, the sixth embodiment of the non-contacting conveyance equipment of the present invention is explained using  FIG. 13 . 
     FIG. 13  is a perspective view of the sixth embodiment of non-contacting conveyance equipment. Non-contacting conveyance equipment  51  is equipped with fluid piping  58 , which penetrates inside a fluid swirl formation object  52  to a circumference-like concave part  53 , and also penetrates inside a long and slender pillar-shaped grasping part  57 , and fluid swirl formation object  52  is fixed to the end of fluid piping  58  in  FIG. 13 . 
   Fluid introduction mouth  56  (which opens to the perimeter side of concave part  53 ), spout  54  (which is faced at concave part  53 ), and fluid introduction mouth  56  and spout  54  are prepared in fluid passage  55  by fluid swirl formation object  52 . Fluid piping  58  is connected to fluid introduction mouth  56 , and air supplied from fluid piping  58  is breathed out along the direction of a circumference through fluid introduction mouth  56  and fluid passage  55  in a concave  53  from a spout  54 , and serves as a fluid swirl inside concave part  53 . 
   From a grasping part  57 , two bent guide arms  591 ,  592  extend through both sides of concave part  53 , and are bent perpendicularly at each tip end. If guide arm  592  is pushed in at partial bend  592   a , guide arm  592  moves away from guide arm  591 , which is fixed. According to the operation, if partial bend  592   a  is being pushed in by an operator grasping the grasping part  57 , and the pushing is canceled, then guide arm  592  will return to its original position. 
   Moreover, an opening-and-closing switch  571  opens and closes the passage of fluid piping  58  formed in grasping part  57 . 
   Wafer  9  can be held, even if only one fluid swirl formation object  52  is formed, because of the powerful attraction, and the non-contacting conveyance equipment  51  of the above-mentioned construction holds wafer  9  by non-contacting, as in the case of each of the above-mentioned embodiments, using the outflow of the fluid swirl formed in concave  53 . Therefore, by fixing one fluid swirl formation object  52  to the end of fluid piping  58 , and by holding grasping part  57 , and operating it by hand, wafer  9  is held freely as with tweezers and can be conveyed to a desired position. When catching wafer  9 , partial bend  592   a  is pushed in, which moves guide arm  592  to the open position of the dotted lines of  FIG. 13 , wafer  9  becomes easy to catch, concave part  53  is brought close to wafer  9  with guide arms  591 ,  592  in an open state, and maintenance by non-contacting is caused to perform, since guide arms  591 , 592  are formed. Then, at the time of conveyance, pushing of partial bend  592   a  is canceled, guide arm  592  returns to its original position, and wafer  9  can be conveyed with movement of wafer  9  prevented and stabilized by the perpendicular bending portions formed in the ends of guide arms  591 , 592 . Thus, like tweezers, non-contacting conveyance equipment  51  in this sixth? embodiment is free to catch and convey wafer  9 . 
   Although air is used as fluid, gases or liquids other than air may be used in each of the above-mentioned embodiments. 
   Moreover, although it was explained above that the object held by non-contacting was a silicon wafer, the present invention is also considered ideal for holding by non-contact objects other than wafers. 
   Moreover, although each of the concave parts  3 ,  33 ,  43 , and  53  were explained as having a circumference-like shape, the concave parts  3 ,  33 ,  43 , and  53  may be formed as other shapes, such as a polygon-like shape. 
   Next, a seventh embodiment of the non-contacting conveyance equipment of the present invention is explained with reference to  FIG. 14 . 
     FIG. 14  is a partial front sectional view of the seventh embodiment of non-contacting conveyance equipment. The construction element in the second embodiment described above is used in this seventh embodiment, and the same numerals are allocated to the same elements, explanation omitted. 
   Non-contacting conveyance equipment  61  of the seventh embodiment differs from the above-mentioned non-contacting conveyance equipment  11  of the second embodiment at the following points. First, at the point which was open for free passage of the ultrasonic air source  610 , which forms two fluid supply mouths  15  in each of the fluid swirl formation objects  2 , and which vibrates at an ultrasonic frequency for each. Second, at a point established so that the inside of concave part  3  of fluid swirl formation object  2  might be faced with an ion generation source  600 . 
   Ion generation source  600  has an electric pole needle  601  and a high-voltage power supply  602  that supplies high voltage to electric pole needle  601 , as shown in  FIG. 14 . Electric pole needle  601  is formed so that the tip faces the internal space of concave part  3  of fluid swirl formation object  2 , from a hole  603  prepared in base  13 . By supplying high voltage, ions are generated around the tip portion of electric pole needle  601 . Moreover, from fluid supply mouth  15 , the ultrasonic air supplied from ultrasonic air source  610  is used as the supply fluid. 
   Electric-pole needle  601  generates ions with polarity according to the polarity of the voltage supplied. The ions are carried to the ultrasonic air supplied from fluid supply mouth  15 , and pass through to the surface of wafer  9  which is held by non-contacting. The ions are attracted by fluid outlet  16 , which is open for free passage to vacuum pump  611 , and are discharged to the outside via vacuum pump  611 . 
   Usually, the removal of particles from wafers is difficult because particles tend to adhere to the wafer surface when wafer  9  is charged. In this seventh embodiment, as mentioned above, since ions are blown and contact the surface of wafer  9 , the electrification is neutralized and adhesion of particles by static electricity is weakened. Therefore, the supply fluid from fluid supply mouth  15  can easily remove the particles, whose adhesion is weakened, and the surface of wafer  9  is cleaned. The removed particles are discharged with supply fluid from fluid outlet  16 . 
   The supply fluid in this seventh embodiment is also converted into ultrasonic air. The oscillating air of this ultrasonic fluid acts to vibrate the air layer near the wafer surface and thereby exfoliates particles from the surface of wafer  9 . The action effect of particle removal is strengthened further and particles on wafer  9  are more reliably removed. Moreover, since wafer  9  is neutralized with ions, particle adhesion to wafer  9  by subsequent electrification can be prevented. 
   In addition, in this embodiment, although ion generation source  600  and ultrasonic air source  610  are used together, even when only one of these two sources is used, the effect of particle removal will still be demonstrated. For example, without preparing an ion generation source  600  in the fluid supply mouth, ultrasonic air source  610  is made to open for free passage and it supplies ultrasonic air fluid. Moreover, only an ion generation source  600  can be prepared in the fluid supply mouth, and it will supply normal non-ultrasonic fluid. The effect of particle removal can be demonstrated in either case. 
   Non-contacting conveyance equipment  61  of this seventh embodiment is capable of holding and conveying an object by non-contacting. Moreover, it can now serve as both static electricity removal equipment that neutralizes static electricity, and as cleaning equipment that removes particles by preparing an ion generation source. Moreover, it can serve as cleaning equipment that performs particle removal by using only ultrasonic air for the supply fluid. Furthermore, by making the supply fluid into ultrasonic air while preparing an ion generation source, this equipment can now serve as the both static electricity removal equipment and cleaning equipment, and can still realize various functions of non-contacting conveyance equipment. 
     FIG. 15  is a partial front sectional view of the eighth embodiment of the non-contacting conveyance equipment. 
   The point at which non-contacting conveyance equipment  71  of this 8th embodiment differs from the above-mentioned non-contacting conveyance equipment  61  of the seventh embodiment is the point in the seventh embodiment which did not form electric pole  601  of ultrasonic air source  600  in fluid swirl formation object  2 , but was rather formed so that wafer  9  currently held by non-contacting might be attained. That is, the point in the eighth embodiment where an electric pole  601  is formed in base  13 , not a fluid swirl formation object  2 , and wafer  9  currently held by non-contacting is made to overlook the tip of an electric pole  601 . Moreover, the eighth embodiment differs at the point where fluid supply mouth  151  leads to ultrasonic air source  610 , formed at hole  604 . 
   Thus, since the ions generated by electric pole  601  contact the surface of wafer  9 , the eighth embodiment demonstrates at least the same non-contacting effect as that of the seventh above-mentioned embodiment. In addition, though fluid supply mouth  151  which supplies ultrasonic air in this case has an additional fluid supply mouth  15  supplying fluid swirl formation object  2 , the flux of the ultrasonic air is enough if it is the flux of the fluid which arrives at the surface of wafer  9 . Also, the non-contacting maintenance of wafer  9  held by the fluid supplied to fluid swirl formation object  2  is not affected. 
   Moreover, the particles removed by the ions and ultrasonic air are promptly discharged via fluid outlet  16  prepared in two or more places in base  13 . 
   In addition, although the seventh and the eighth embodiments are constructed so that the ultrasonic air from source  610  of ultrasonic air can be ionized by electric pole  601 , these may also be constructed such that the air is first ionized by the electric pole, and then fed to the ultrasonic air source, so that the ionized air may be given ultrasonic vibration. As long as the ionized ultrasonic air finally contacts the object held by non-contacting, either construction is acceptable. 
   Since the present invention consists of the above-mentioned construction, the effects explained below can also be accomplished. 
   The present invention performs non-contacting maintenance of an object by the use of a concave part, a flat surface, and a fluid passage. Therefore, the equipment can be easily constructed and the cost of manufacturing the equipment is reduced sharply. 
   Moreover, because the equipment is easily constructed, it is also easily miniaturized. So miniaturized, it can be used and inserted into spaces not used conventionally. The action range of the equipment can be extended, and conveyance movement in a narrow domain within the same process and processing equipment can also be freely performed. 
   Moreover, the air blown into the concave part serves as a fluid swirl, smoothly flowing, receiving minimal passage resistance. Therefore, energy efficiency can be improved and energy curtailment can be realized. 
   Furthermore, air is made to blow off in a circumferential direction in the concave part, generating a fluid swirl. Therefore, the power of attraction by the negative pressure between a flat surface and an object can be markedly increased as compared with conventional devices, allowing powerful performance of non-contacting maintenance. 
   The present invention may be made to attract a object by the fluid swirl formed by two or more concave parts, increasing the power of attraction markedly, and due to such power, the whole of an object is more powerfully attracted. Therefore, it becomes possible to correct a curvature of the whole object (for example, wafer). Consequently, even in a case where a large diameter object has a curvature, the object can be reliably held by non-contacting, and when conveyance is stabilized, it can carry the object with certainty. 
   A concave part is formed in a board-like base, a fluid swirl is formed therein, and non-contacting maintenance may be performed. For this reason, conventionally stacked wafers may be freely accessed and attained, even when the wafers are in a difficult to access wafer cassette, or the wafer of which stage. A wafer retrieved from the wafer cassette can be conveyed more smoothly and freely. Moreover, in the case where a wafer cassette is contained and loaded with the wafer, it can be freely carried to a desired position. That is, the acts of taking out from the wafer cassette and carrying in to the wafer cassette can be performed freely, and working efficiency can be raised sharply. 
   Moreover, the non-contacting maintenance power is great, and even if the non-contacting conveyance equipment reverses, the state is maintained. Moreover, the wafer can be reversed and the wafer cassette can also be loaded, reversed, and conveyed to a subsequent processing stage. 
   Moreover, ions from an ion supply source are caused to contact an object. Therefore, the electrification is neutralized and adhesion of particles by static electricity to an object is weakened. The supply fluid can easily remove particles whose static adhesion is weakened, consequently cleaning the object. 
   While the invention has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon obtaining an understanding of the foregoing may readily conceive of alterations to, variations on and equivalents to these embodiments. Accordingly, the scope of the present invention should be assessed as that of the appended claims and any equivalents thereto.