JP2007214529A - Bernoulli chuck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a Bernoulli chuck 1 for suction holding mainly 3A for dispensing with inserting a suction holding plate 7 to the depth of a cassette for a wafer by sucking a work W while sliding it so as to pull it to this side, and for forming the suction holding plate 7 to be thin and making it easy to work channel forming members 12 and 13. <P>SOLUTION: Communicating channels 11 are provided in the suction holding plate 7, and connected with a discharge channel 10 of a high pressure gas. At the distal end side of the suction holding plate 7, channel forming members 12 and 13 are bruied as provided with jet ports 8 and 9 of the high pressure gas opening to the suction face side. The channel forming members 12 and 13 are provided with communication holes 12d and 13d which are formed tilting to a rear end side, whose respectively one ends are connected to the communicating channels 11 and the other ends of which are connected to the jet ports 8 and 9. At the rear end side of the suction holding plate 7, a stopper 14 to the work W is formed projecting from the suction face. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, a high-pressure gas such as air or nitrogen gas is injected from an injection port provided on the adsorption surface of the adsorption holding plate, and is caused to flow at a high speed along the surface of the thin plate workpiece, and between the adsorption surface and the workpiece surface. A Bernoulli chuck that sucks and holds a workpiece in a non-contact state by a Bernoulli effect due to the generated negative pressure, and is used, for example, when a semiconductor wafer or other thin plate-like workpiece is sucked and held to change the position. However, it is particularly suitable for loading and unloading semiconductor wafers with respect to the wafer cassette.

As a means for holding and holding a thin plate workpiece, a vacuum chuck type is used in which a vacuum is drawn from a suction port provided on the suction surface of the suction holding plate and the workpiece is sucked and held in contact with the suction surface of the suction holding plate (Patent Document 1). 2), and a high pressure gas is jetted from an injection port provided on the suction surface of the suction holding plate, and due to the Bernoulli effect due to the negative pressure generated between the suction surface and the workpiece surface, There is a Bernoulli chuck type (Patent Documents 3 and 4) that holds and holds a workpiece in a non-contact state, and a combined chuck type (Patent Documents 5 and 6) that uses both vacuum suction and the Bernoulli effect.
JP 2003-086667 A JP 2005-093893 A JP 2005-142462 A Japanese Patent Laid-Open No. 2005-251984 JP 2004-193195 A Japanese Patent Laying-Open No. 2005-074606

  In these prior arts, in any case of suction holding using any method, the workpiece is sucked in the orthogonal direction with respect to the suction surface of the suction holding plate. For example, a large number of ribs are formed on the inner surfaces of both side walls. When a wafer is taken out from a wafer cassette having juxtaposed partition members, the suction holding plate is inserted deeply while the interval between adjacent partition members is narrow and the adjacent wafers are approaching. Since it is necessary, the wafer may collide with the partition member at the time of suction, contact may be generated when the wafer is pulled up, friction may be caused, or damage or deterioration or generation of particles may reduce the performance of the workpiece.

  In particular, in the case of the vacuum chuck type, the work is sucked and held in contact with the suction surface, so that the work is damaged or deteriorated due to contact with the suction surface at the time of suction, or the performance is degraded due to generation of particles. In the case of the Bernoulli chuck type, it is necessary to provide a swirling flow path for injecting a high-pressure gas as a swirling flow from the injection port. However, the processing for forming this swirling flow path is not easy, and adsorption holding In addition to preventing the plate from being thinned, the workpiece may rotate during suction due to unbalanced swirling flow and contact the partition member, causing damage or deterioration of the workpiece, or deterioration of performance due to generation of particles, etc. was there.

  Therefore, the present invention provides a suction holding unit that can solve these problems of the prior art, and is a Bernoulli chuck type that holds and holds in a non-contact state. In particular, the injection port is provided through an inclined communication hole. By adopting a configuration in which high pressure gas is jetted in a straight line in a predetermined direction (for example, the front side in the case of handling by hand), the workpiece can be adsorbed while being slid so as to be drawn toward the front, and the adsorption holding plate is attached to the wafer. It is a Bernoulli chuck whose main purpose is to make it unnecessary to insert the cassette to the back of the cassette, to make it possible to form a thin suction holding plate and to easily process the flow path forming member.

  The Bernoulli chuck according to the present invention is a Bernoulli chuck having an adsorption holding plate for adsorbing a workpiece in a non-contact state, and is provided in a discharge passage for high-pressure gas to be discharged from a gas pressure source to the adsorption holding plate by an opening / closing operation. A communication channel to be connected; an injection port that opens to an adsorption surface that adsorbs the workpiece; and a communication hole that communicates with the communication channel and the injection port and is inclined with respect to the adsorption surface. And a stopper for supporting the edge portion of the workpiece is provided on the injection direction side of the high-pressure gas injected from the injection port with respect to the injection port. (Claim 1)

  2. The Bernoulli chuck according to claim 1, wherein the injection port and the communication hole are formed in a flow path forming member that is a separate member from the suction holding plate, and the flow path forming member is embedded in the suction holding plate. It was. (Claim 2)

  The Bernoulli chuck according to claim 1 or 2 can take a form in which the inclination angle of the communication hole formed in the flow path forming member is set in the range of 8 to 20 degrees. (Claim 3)

  4. The Bernoulli chuck according to claim 2, wherein the flow path forming member has a first flow path forming member arranged in parallel in the front-rear direction and the direction of the jet port in the front-rear direction. In contrast, a configuration may be adopted in which a predetermined opening angle is formed on the outer side and the second channel forming member is disposed symmetrically outward from the first channel forming member. (Claim 4)

  In the Bernoulli chuck according to claim 4, each of the injection ports formed in the second flow path forming member can take a form in which an opening angle is set in a range of 10 to 40 degrees. (Claim 5)

  The Bernoulli chuck according to any one of claims 1 to 5, wherein a rear surface side ejection hole communicating with the communication channel is provided on a rear surface of the suction holding plate opposite to the suction surface. (Claim 6)

  In the Bernoulli chuck according to claim 1, when the workpiece is brought close to the suction holding surface of the suction holding plate through the injection port in a state where high pressure gas is injected, a stopper is formed along the gap formed between the workpiece and the suction surface. The high-pressure gas flows to the near side, and negative pressure is generated in the gap by the Bernoulli effect, so that the workpiece is adsorbed and held on the adsorption surface in a non-contact state. By injecting the high pressure gas at high pressure, the work is sucked while sliding toward the stopper where the high pressure gas flows.

  Thus, for example, when a semiconductor wafer accommodated in a wafer cassette is used as a workpiece when taking it out for transfer, it is not necessary to insert the suction holding plate deeply, and the workpiece (semiconductor) is inserted with the tip side shallowly inserted. Since the wafer can be sucked and held while pulling it up, the risk of bringing the suction holding plate into contact with the workpiece (semiconductor wafer) or the partition member with which the workpiece is fitted is reduced, and the workpiece is damaged or deteriorated. Or performance degradation due to generation of particles or the like can be prevented. In addition, when a plurality of injection ports are provided, the direction of each injection port is generally aligned so that the high-pressure gas injected at a high pressure from the injection port can be converted into a straight flow that is not a swirling flow. (Semiconductor wafer) is not unstable due to a rotational force applied to the semiconductor wafer.

  Further, the flow path forming member can be easily processed by providing the communication hole inclined to the suction surface and the injection port opening in the suction surface in the separate flow path forming member. The suction holding plate in which the flow path forming member is embedded can be made thin, so that the pitch of each workpiece (semiconductor wafer) accommodated adjacent to the wafer cassette is narrow. Even in this case, it is possible to reduce the risk of bringing the suction holding plate into contact with a workpiece (semiconductor wafer) or a partition member into which the workpiece is fitted. By using a separate flow path forming member, the position and number embedded in the suction holding plate can be arbitrarily set according to the work, and therefore, it can be easily handled without making a large design change.

  If the inclination angle is too large, the communication hole formed in the flow path forming member decreases the suction force due to the Bernoulli effect, and particularly when the injection pressure is low, the suction cannot be performed, and when the injection pressure is increased, the suction is not performed. However, if the distance between the gaps increases and the stopper is moved over, the suction holding becomes unstable, and if the tilt angle is too small, the workpiece (semiconductor wafer) is sucked without sliding. Thus, it is set in the range of 8 to 20 degrees, and more desirably, it is set to around 13 degrees.

  Further, when the diameter of the workpiece to be sucked and held is small, the flow path forming member may be only the first flow path forming member in which the directions of the ejection ports are arranged in parallel to each other, but the workpiece having a large diameter In this case, since it becomes difficult to take a balance between front and rear or left and right at the time of adsorption, the injection port is set to a predetermined opening angle outward with respect to the direction of the injection port of the first flow path forming member as in claim 4. If the second flow path forming members arranged symmetrically are used in combination, a balance can be obtained.

  That is, the injection port formed in the second flow path forming member can increase the suction force in cooperation with the injection port formed in the first flow path forming member. When the opening force is changed and the opening angle is reduced, the suction force on the tip side increases with respect to the rear end side of the work and is first picked up. Thus, the front-rear direction is balanced, and the left-right direction is balanced by arranging it symmetrically outward from the first flow path forming member. The opening angle is as in claim 5. It is set within a range of 10 to 40 degrees, and more preferably around 25 degrees.

  In addition, when one workpiece is taken out by inserting between adjacent workpieces, if the gap between the workpieces is narrow, there is a possibility that a Bernoulli force is generated between the two workpieces due to the airflow passing between both workpieces, and the phenomenon between the two workpieces may be narrowed. Therefore, by providing the back surface side ejection hole on the back surface of the suction holding plate as in claim 6, it is possible to prevent the work on the back surface side of the suction holding plate from approaching by ejecting high pressure gas from the back surface side ejection hole. Even when the space between the workpieces is narrow, the work of inserting between the workpieces and taking out the workpiece can be performed without any problem.

  The suction holding portion of the Bernoulli chuck according to the present invention will be described in detail with reference to the accompanying drawings (FIGS. 1 to 11) showing a preferred embodiment to which the present invention is applied. In the illustrated embodiment, a thin plate shape such as a semiconductor wafer is described. 1 is applied to a hand-held Bernoulli chuck 1 that moves and moves the workpiece W by suction. FIG. 1 is an overall perspective view as seen from the bottom side with the suction surface, and FIG. 2 shows the Bernoulli chuck 1. FIG. 3 and FIG. 4 are detailed views of the suction holding plate as the main part.

  The Bernoulli chuck 1 is composed of a chuck body 2 that is gripped by a hand to open and close a flow path, and a suction unit 3 that is attached to the tip end side of the chuck body 2 and sucks and holds a workpiece W. 2 is used in a state where a discharge pipe 4 connected to a discharge pump (not shown) as a gas pressure source is connected to the rear end side of the chuck 2. The chuck body 2 opens and closes the flow path by operating a push button. A front opening / closing operation part 2A fitted with the opening / closing valve 5 and a rear gripping operation part 2B fitted with a connection connector 6 to the discharge pipe 4 are integrally connected.

  The suction unit 3 connects a suction flow path to the suction holding unit 3A including the suction holding plate 7 and a plurality of ejection ports 8 and 9 provided in the suction holding plate 7, and is connected to the opening / closing operation unit 2A of the chuck body 2. The connection support portion 3B is configured to connect and support the suction unit 3, and a branch flow passage (in the drawing) that branches the discharge flow passage opened and closed by the open / close valve 5 into two Y-shapes inside the connection support portion 3B. The branch flow path is communicated with the injection ports 8 and 9 of the suction holding plate 7 via the branch pipes 10 and 10 arranged in parallel.

  3A is a plan view seen from the suction surface side shown in FIG. 3, a longitudinal sectional view along line XX shown in FIG. 4A, and a YY line shown in FIG. 4B. As shown in the cross-sectional view along the line, for example, a suction holding plate 7 made of a synthetic resin material having a thin plate shape of about 4 mm is used. Inside the suction holding plate 7, each branch pipe 10 and each injection port are provided. In addition to providing a plurality of communication channels 11 communicating with 8, 9, channel holding members 12, 13 in which the respective injection ports 8, 9 are formed are embedded in the suction holding plate 7, and a workpiece is provided on one side of the suction surface. A plurality of stoppers 14 for W are formed to protrude.

  Since the adsorption holding plate 7 is used under high temperature and environmental conditions with chemicals, it is required to have excellent heat resistance and chemical resistance, and particles generated by friction or the like are generated on the workpiece W (wafer). In order to prevent adhesion and contamination, it is desirable to use a synthetic resin material having electrical conductivity. For example, a nylon resin (nylon 6) containing carbon fiber or a carbon nanotube can be used to meet these conditions. PEEK resin containing polyethylene (polyether ether ketone) can be used.

  The flow path forming members 12 and 13 are formed of a cylindrical body in which an annular groove 12c or 13c is provided between the flanges 12a and 12b or 13a and 13b on both sides, and the annular groove 12c or toward the flange 12a or 13a on one side. An inclined communication hole 12d or 13d is formed from 13c, and each of the communication channels 11 is communicated with the annular grooves 12c and 13c. By doing so, the high-pressure gas taken into each communication channel 11 in the adsorption holding plate 7 through each branch pipe 10 is jetted from each jet port 8 and 9 at a high pressure.

  The high-pressure gas injected at high pressure is injected from the suction surface along the inclination angle α of the communication holes 12 d and 13 d formed in the flow path forming members 12 and 13, and the injection direction is a flow path embedded in the suction holding plate 7. It is possible to arbitrarily set the direction depending on the orientation of the forming members 12 and 13, and in the illustrated embodiment, the flow path forming member 12 is arranged at the center along the line XX, and its injection port 8 is set to YY. The flow path forming member 13 is arranged on both sides of the center along the line XX, and the injection port 9 is opened at the constant opening angle β along the line YY. ing.

  As a result, high-pressure gas is injected at a predetermined inclination angle α from the suction surface of the suction holding plate 7 through each of the injection ports 8 and 9, but when the work W is brought close to this suction surface, the flow path is blocked. In addition, the high pressure gas flows toward the front side of the stopper 14 along the gap formed between the workpiece W and the suction surface, and negative pressure can be generated in the gap by the Bernoulli effect. The workpiece W can be sucked and held on the suction surface of the plate 7 in a non-contact state.

  At this time, the workpiece W is sucked while being slid toward the stopper 14 through which the high-pressure gas flows by injecting the high-pressure gas at a predetermined inclination angle α from the suction surface of the suction holding plate 7. The outer shape of the workpiece W can be held by the stopper 14 so that the suctioned and held workpiece W can be sucked and held in a non-contact state in which a minute gap in which the suction force and the repulsive force are balanced is held. To be locked.

  The stopper 14 is preferably attached with a cushioning material so as to absorb the impact at the time of suction and to frictionally engage the outer surface of the locked workpiece W to increase the locking holding force. In this case, a pin made of a homogeneous material is detachably mounted in a mounting hole drilled in the suction holding plate 7, and a cap made of urethane rubber or the like is attached to the outer periphery of the pin as a cushioning material. The form to wear can also be taken.

  In this suction and holding, the inclination angle α of the communication holes 12d and 13d and the opening angle β of the injection port 9 play an important role in the flow path forming members 12 and 13 in which the respective injection ports 8 and 9 are formed. If the inclination angle α of the holes 12d and 13d is too large, the repulsive force will be greater than the suction force and the workpiece W will be separated, and conversely if the inclination angle α is too small, the workpiece W will be attracted without sliding forward. At the same time, processing of the communication holes 12d and 13d with respect to the flow path forming members 12 and 13 becomes difficult. Therefore, particularly when the workpiece W is attracted to be pulled out from the cassette, it is necessary to set an appropriate predetermined inclination angle α. is there.

  As for the inclination angle α, the present inventors have conducted various tests. When the inclination angle α is 25 degrees or more, adsorption is not possible when the injection pressure is low, and when the injection pressure is high, adsorption is not possible. However, the distance of the gap becomes large and the stopper 14 is moved over, so that the suction holding becomes unstable. When the inclination angle α is 5 degrees or less, the suction can be performed regardless of the level of the injection pressure, but the sliding distance gradually decreases. Therefore, the inclination angle α is preferably in the range of 8 to 20 degrees. In the illustrated embodiment, the inclination angle α is set to approximately 13 degrees in consideration of the workability of the communication hole, and is locked to the stopper 14 at a slide distance of 30 to 40 cm. I have to.

  Further, by arranging the injection ports 9 symmetrically in a state where the opening angle β is provided, it is possible to adjust the suction balance between the rear end side close to the stopper 14, the front end side away from the stopper 14, and the left and right. The suction force on the tip side of the workpiece W changes depending on the size of the opening angle β, and when the opening angle β is reduced, the suction force on the tip side increases with respect to the rear end side of the workpiece W, so that the suction is first performed. Therefore, the opening angle β is preferably in the range of 10 to 40 degrees so as to attract evenly, and is set to about 25 degrees in the illustrated embodiment.

  In addition, the suction pressure is influenced by the injection pressure from each of the injection ports 8 and 9 and the arrangement of the flow path forming members 12 and 13, but the setting of the injection pressure varies depending on the diameter and weight of the workpiece W. If the pressure is too low, the adsorptive power is reduced, and if it is too high, the stability is lowered, for example, vibration is generated at the time of adsorption. Therefore, the injection pressure is preferably in the range of 30 to 50 mPa (millipascal). In the form, it is set to 40 mPa.

  In the arrangement of the flow path forming members 12 and 13 according to the illustrated embodiment, the high pressure gas from the injection port 8 of the flow path forming member 12 arranged on the near side adsorbs the work W while sliding it toward the stopper 14 side, The high-pressure gas from each injection port 9 of the flow path forming members 13 and 13 disposed in front of the work balances the front and rear of the workpiece W and the left and right (two axes orthogonal to each other on the workpiece suction surface). It has been confirmed that the flow path forming member 12 functions in the same way even if the flow path forming member 12 is divided into two and distributed symmetrically, and the flow path forming member 12 and the flow path forming member 13 are reversed. In the case of the arrangement, it has also been confirmed that the adsorption force decreases and the balance at the time of adsorption becomes unstable.

  Next, the usage state of the Bernoulli chuck 1 (not shown in its entirety including the chuck main body 2) to which the suction unit 3 is mounted will be described with reference to FIGS. 5A and 5B. In this case, the wafer cassettes 15 and 16 are divided by rib-like partition members 15a and 16a formed on the inner surfaces of both side walls, and the adjacent partition members 15a are replaced. , 16a is a container that can store a semiconductor wafer to be a workpiece W1.

  First, the on-off valve 5 on the chuck body 2 side is operated to bring the discharge channel into communication, and the tip end side of the suction holding portion 3A is inserted into the wafer cassette 15 as shown in FIG. When the suction surface of the suction holding plate 7 provided with 9 is placed close to the workpiece W1 (semiconductor wafer), high pressure is jetted from the jet ports 8 and 9 into the gap between the suction surface of the suction holding plate 7 and the workpiece W1. Since the gas flows and the negative pressure due to the Bernoulli effect is generated, the workpiece W1 is adsorbed while sliding to the stopper 14 side, and can be adsorbed and held in a state where the outer peripheral surface of the workpiece W1 is in contact with the stopper 14 like a virtual line. It can be lifted upward and taken out from the wafer cassette 15.

  Further, the workpiece W1 taken out as shown in FIG. 5B continues to be sucked and held on the suction surface of the suction holding plate 7, moved to the upper side of the mounting portion for the wafer cassette 16 to be replaced, and sucked between the partition members 16a. When the discharge passage is closed by operating the opening / closing valve 5 on the chuck body 2 side after the front end side of the holding plate 7 is inserted, the high-pressure gas from the injection ports 8 and 9 that have been subjected to high-pressure injection stops. The negative pressure generated by the Bernoulli effect disappears, and the workpiece W1 naturally falls from the suction surface of the suction holding plate 7 to complete the transfer.

  Next, a second embodiment for the suction holding portion in the Bernoulli chuck 1 will be described with reference to FIGS. 6 and 7. The suction holding portion 17 according to this embodiment can be applied to a workpiece W2 (semiconductor wafer) having a large diameter. In addition, three sets of injection port groups 19 (19A, 19B, 19C) configured in the same manner as the injection ports 8 and 9 in the suction holding unit 3A are distributed evenly with respect to the suction surface of the suction holding plate 18, and Each stopper 20 is provided on the rear end side of the suction holding plate 18 as in the case of the suction holding portion 3A according to the first embodiment.

  FIG. 7 shows the state of use of the Bernoulli chuck 1 (not shown in its entirety including the chuck main body 2) to which the suction holding unit 17 is attached, but a large wafer cassette containing a workpiece W2 (semiconductor wafer) having a large diameter. 21, the tip side of the suction holding plate 18 is inserted in the same manner as in the first embodiment, and the suction surface provided with the ejection port group 19 (19A, 19B, 19C) is close to the workpiece W2 (semiconductor wafer). Therefore, it can be adsorbed and held by the Bernoulli effect by the high pressure gas jetted from the jet port group 19 and taken out from the wafer cassette 21.

  Next, with reference to FIGS. 8, 9A, and 9B, a third embodiment for the suction holding portion of the Bernoulli chuck 1 will be described. The suction holding portion 22 according to this embodiment is a rectangular workpiece W3 (semiconductor wafer). The injection ports 24 and 25 are provided on the suction surface of the suction holding plate 23 in the same manner as the injection ports 8 and 9, and the stoppers 26 are provided on the rear side. Was fitted with a cushioning material such as a rubber cap to lock the end face of the workpiece W3.

  FIGS. 9A and 9B show the use state of the Bernoulli chuck 1 (not shown in its entirety including the chuck main body 2) with the suction holding unit 22 mounted thereon, but the rectangular workpiece W3 (stored in the wafer cassette 28). The workpiece W3 (semiconductor wafer) can be horizontally mounted on the mounting table 29 prepared in the next step after the semiconductor wafer is picked up and held by the suction surface of the suction holding plate 23.

  Next, a fourth embodiment for the suction holding portion in the Bernoulli chuck 1 will be described with reference to FIGS. 10 and 11. The suction holding portion 30 according to this embodiment is applied to the case of a square and wide workpiece W4 (semiconductor wafer). Two sets of injection port groups 32 (32A, 32B) configured in the same manner as the injection ports 24 and 25 in the suction holding unit 22 with respect to the suction surface of the suction holding plate 31 are distributed to the left and right objects so that they can be made. Each stopper 33 is provided on the rear end side of the suction holding plate 31, and a rubber cap is attached to each stopper 33 in the same manner as in the fourth embodiment so that the end face of the workpiece W4 is locked.

  FIG. 11 shows the state of use of the Bernoulli chuck 1 (the entire illustration including the chuck body 2 is omitted) equipped with the suction holding unit 30, but a large wafer containing a rectangular and wide workpiece W 4 (semiconductor wafer). In the same manner as in the third embodiment, the front end side of the suction holding plate 31 is inserted into the cassette 35 for use, and the suction surface provided with the ejection port group 32 (32A, 32B) is close to the workpiece W4 (semiconductor wafer). Therefore, the wafer can be adsorbed and held by the Bernoulli effect by the high-pressure gas jetted from the jet port group 32 and taken out from the wafer cassette 35.

  The stoppers 14, 20, 26, and 33 in each embodiment are provided in two or more depending on the shape of the workpiece W and the size of the diameter. In the illustrated embodiment, the stoppers 14, 20, 26, and 33 have a square shape and a case where the workpiece W has a circular shape. In this case, three attachment holes for embedding the stopper are provided so that the suction holding plate can be shared, and when the workpiece W is circular, the stopper is positioned at the center and used.

  As described above, the preferred embodiments of the present invention have been described with reference to the drawings. However, the present invention is not limited to the illustrated embodiments, and various modifications can be made within the scope of the gist, In the illustrated embodiment, a hand-held Bernoulli chuck that is gripped and operated by hand has been described. However, instead of the chuck body, as in Patent Document 1 and Patent Document 3, the tip side of a movable arm that is operated by an automatic machine It is also possible to adopt a form in which a suction holding unit or a suction unit including the suction holding unit is mounted.

  In addition, for example, the number and arrangement of flow path forming members provided with injection ports can be changed to forms other than those shown in the figure, which have similar functions, or a stopper is formed by providing a suction surface and a step on the rear end side of the suction holding plate. In the case of a circular workpiece, this stepped surface is an arc-shaped and rectangular workpiece, and in the case of a square workpiece, the stepped surface is a straight stopper surface, and the stopper surface is provided with a cushioning material such as a urethane rubber plate. Various modifications can be made within the scope of the gist.

  Next, a fifth embodiment of the present invention will be described below with reference to FIG. In addition, the same code | symbol is attached | subjected to the part similar to the said example of illustration, and the detailed description is abbreviate | omitted. As shown in FIG. 12, a suction holding plate 42 similar to the stopper (7 etc.) in the illustrated example is coupled to the tip of the pipe 41 corresponding to the branch pipe 10 in the illustrated example. A stopper support member 43 is fixed to the intermediate portion of the. The stopper support member 43 is a horizontally long plate extending on both sides of the pipe 41 and is formed symmetrically with the pipe 41 as a target axis.

  The pipe 41 may be a round pipe, and is formed into a shape having a round pipe portion 41a on the discharge pump side and a flat pipe portion 41b on the suction holding plate 42 side. Note that the flat pipe portion 41b can be formed by pressing so that the round pipe is crushed in the radial direction and flattened. Then, the flat pipe portion 41b is received in the groove 43a having a flat cross section provided in the intermediate portion of the stopper support member 43, and the pressing member 44 is crossed across the surface of the flat pipe portion 41b in the state of being accommodated in the groove 43a. And the pipe 41 and the stopper support member 43 are integrated.

  In addition, a pair of left and right pin-shaped stoppers 45 protrude from predetermined positions at both ends in the longitudinal direction (left and right direction) of the stopper support member 43. These stoppers 45 may be the same as the stoppers (14 and the like) in the illustrated example.

  As shown in FIG. 13, the suction holding plate 42 includes a flat hole 43 into which the tip of the flat pipe portion 41 b is inserted, and a plurality of vertical and horizontal holes that communicate with the flat hole 43 and communicate with each other. The communication flow path 44 is formed inside. In the connection between the flat pipe portion 41 b and the flat hole 43, for example, a buried material and an adhesive similar to the suction holding plate 42 may be applied and pressed into the flat hole 43 and heat-bonded. The communication channel 44 may be formed by drilling from the outer peripheral surface of the suction holding plate 42 with a drill and closing the portion opened to the outer peripheral surface side with a filler (hatched hatching in the figure). It can also be formed by other processing methods such as bonding two thin plates. In any case, any structure that can withstand a pressure of, for example, 0.4 to 0.5 MPa supplied to the communication path 44 may be used, and the formation method of the communication path 44 is not limited.

  In addition, by using a pipe shape like the illustrated example in which one end side is flattened using a single round pipe, the suction holding plate 42 can be made thin and a large flow rate can be handled. Thereby, size reduction of the adsorption holding plate 42 can be promoted, and if it is the same size, an effect that a larger workpiece can be handled can be obtained.

  The four communication holes 45a and 45b formed so as to extend obliquely from the communication flow path 44 toward the suction surface 42a that is one surface of the suction holding plate 42 are the same as the communication holes 12d and 13d in the illustrated example. Correspondingly, the respective injection ports 46a and 46b serving as openings in the suction surfaces 42a of the respective communication holes 45a and 45b correspond to the injection ports 8 and 9 in the illustrated example. Accordingly, the inclination angle α and the opening angle β of the communication holes 45a and 45b may be the same as those in the illustrated example. In the processing of the communication holes 45a and 45b, for example, the auxiliary processing member is fixed in close contact with the suction surface 42a, and the corresponding portions of the auxiliary processing member on the extension line of the communication holes 45a and 45b are connected to the communication holes. Drilling with a drill can be easily performed by forming a flat surface perpendicular to the axes of 45a and 45b.

  Further, as shown in FIG. 14, the suction holding plate 42 is provided with two back side ejection holes 46c in the illustrated example at appropriate positions on the back side 42b which is the other side opposite to the suction side 42a. It has been. Each back side ejection hole 46c in the illustrated example communicates with the inside and the bottom three in the horizontal direction of the communication channel 44 in the upper and lower sides of the figure and is perpendicular to the back side 42b. Opened in the direction. In this way, a part of the high-pressure gas supplied to the communication flow path 44 from the respective back surface side ejection holes 46c provided at the two locations of the center portion and the lower portion of the back surface 42b is indicated by an arrow A in the figure. It can be ejected in the vertical direction from the back surface 42b.

  For example, as a preferred form of use of the present invention, adjacent workpieces Wa and Wb in a cassette (15) for holding a plurality of 4 to 6 inch wafers (workpieces) vertically as shown in FIG. 5A as described above. Some distances are about 4.8 mm. In the case where the suction holding plate 42 is inserted in such a place where the space between the workpieces is narrow and either one of the workpieces is sucked and taken out, the thickness of the suction holding plate 42 is reduced as much as possible to make contact with the adjacent workpiece. Can be prevented. In the case of the distance as described above, the thickness of the suction holding plate 42 should be about 3 mm or less, thereby reducing the risk of contact with an adjacent workpiece. For example, if the material of the pipe 41 is stainless steel, it is preferable to use polyimide resin as the material of the suction holding plate 42 in consideration of adhesiveness, and even in that case, the thickness can be formed.

  However, when the work Wa to be picked up is picked up and lifted, the flow of air injected toward the suction face 42a flows between both the works Wa and Wb, and thereby the suction force due to the Bernoulli effect is generated between the two works Wa and Wb. When this occurs, a force that narrows the space between the workpieces Wa and Wb acts, so that the workpiece Wb may come into contact with the back surface 42b of the suction holding plate 42.

  On the other hand, according to the fifth example of the present invention, when a single workpiece is taken out by inserting the suction holding plate 42 between adjacent workpieces, the workpiece Wa to be taken out is the same as in the illustrated example. Since the high-pressure gas is ejected from the back-side ejection holes 46c that open to the back surface 42b of the suction holding plate 42, an air flow is generated between the back surface 42b and the workpiece Wb. A gap due to a positive pressure air flow can be generated between the workpiece Wb. Since the high-pressure gas ejected from the rear surface side ejection hole 46c acts like an air cushion, the gap does not decrease to such an extent that an external force acts on the suction holding plate 42 or the workpiece Wb.

  In the procedure of taking out the workpiece Wa used by inserting the suction holding plate 42, the pipe 41 side is gripped, and the suction holding plate 42 is inserted between the workpieces Wa and Wb while flowing high-pressure gas. The high pressure air current (arrow A in FIG. 14) ejected from the ejection hole 46c can suitably prevent the workpiece Wb from contacting the back surface 42b. Then, as shown in FIG. 14, when the suction holding plate 42 is inserted until the upper end of the suction holding plate 42 reaches the upper edge of the outer periphery of the workpiece Wa, the workpiece Wa is moved from the ejection ports 46 a and 46 b. As shown by the arrow B in the figure, it rises while being adsorbed by the adsorption surface 42a together with the Bernoulli effect described above due to the airflow obliquely upward. The workpiece Wa is raised until the upper peripheral edge of the workpiece Wa abuts against the stopper 45 (arrow C in FIG. 15), and thereafter the workpiece Wa is held by the suction holding plate 42 in a state where the outer peripheral upper edge is in contact with the stopper 45.

  Thereafter, the suction holding plate 42 can be lifted and transferred to another cassette as shown by the arrow D in FIG. 15 together with the workpiece Wa in the suction holding state. Since the airflow in the direction perpendicular to the back surface 42b is ejected from the hole 46c, a gap at a constant interval is maintained between the back surface 42b and the work Wb, and no upward force acts on the work Wb. Therefore, the workpiece Wb is not pulled up when the suction holding plate 42 is pulled up.

1 is an overall perspective view of a Bernoulli chuck equipped with a suction holding unit according to a first embodiment to which the present invention is applied. Fig. 2 shows an exploded perspective view of the Bernoulli chuck of Fig. 1. FIG. 3 is a detailed view of a suction holding unit that is a main part of the Bernoulli chuck in FIGS. 1 and 2, and shows a plan view viewed from the suction surface side. FIGS. 3A and 3B are detailed views of a suction holding unit that is a main part of the Bernoulli chuck in FIGS. 1 and 2, in which FIG. 3A is a longitudinal sectional view taken along line XX in FIG. 3, and FIG. The principal part expanded sectional view, (c) shows the cross-sectional view along the YY line of (a). It is a use state figure of the Bernoulli chuck which equipped with the suction holding part by a 1st example, and is a perspective view in the state where a work W (semiconductor wafer) is taken out from a cassette for wafers. It is a use state figure of the Bernoulli chuck which equipped with the attraction | suction holding | maintenance part by 1st Example, Comprising: The perspective view of the state which inserts the workpiece | work W (semiconductor wafer) in the cassette for wafers is shown. The adsorption holding part by 2nd Example to which this invention is applied is shown with a perspective view. The use state of the Bernoulli chuck | zipper with which the adsorption | suction holding | maintenance part of FIG. 6 was mounted | worn is shown with a perspective view. The adsorption holding part by the 3rd example to which the present invention is applied is shown with a perspective view. FIG. 9 is a use state diagram of the Bernoulli chuck equipped with the suction holding unit of FIG. 8, and shows a perspective view of a state in which a workpiece W (semiconductor wafer) is taken out from the wafer cassette. FIG. 9 is a use state diagram of the Bernoulli chuck equipped with the suction holding unit of FIG. The adsorption holding part by the 4th example to which the present invention is applied is shown with a perspective view. The use state of the Bernoulli chuck | zipper with which the adsorption | suction holding part of FIG. 10 was mounted | worn is shown with a perspective view. A Bernoulli chuck according to a fifth embodiment to which the present invention is applied is shown in a perspective view. It is detail drawing of an adsorption | suction holding board, Comprising: The top view seen from the adsorption surface side is shown. The longitudinal cross-sectional view along the arrow XIV-XIV line | wire of FIG. 13 is shown, and the state which inserted the adsorption holding board between the adjacent workpiece | works is shown. FIG. 15 is a view corresponding to FIG. 14, showing a state where the work is sucked by the suction holding plate and is in contact with the stopper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bernoulli chuck 2 Chuck main body 2A Opening / closing operation part 2B Gripping operation part 3 Adsorption unit 3A, 17, 22, 30 Adsorption holding part 3B Connection support part 4 Discharge piping 5 Opening / closing valve 6 Connection connector 7, 18, 23, 31, 42 Adsorption holding plate 8, 9, 24, 25, 46a, 46b Injection port 10 Branch pipe 11, 44 Communication channel 12, 13 Channel forming member 12a, 12b, 13a, 13b Flange 12c, 13c Annular groove 12d, 13d Communication hole 14, 20, 26, 33, 45 Stopper 15, 16, 21, 35 Wafer cassette 15a, 16a Partition member 19 (19A, 19B, 19C), 32 (32A, 32B) Injection port group α Inclination angle β Opening angle W , W1, W2, W3, W4, Wa, Wb Workpiece (semiconductor wafer)
41 Pipe 43 Stopper support member 45a, 45b Communication hole 46c Back side ejection hole

Claims (6)

A Bernoulli chuck having an adsorption holding plate for adsorbing a workpiece in a non-contact state,
A communication channel connected to a high-pressure gas discharge channel that is discharged from a gas pressure source by an opening / closing operation on the suction holding plate, an injection port that opens to an adsorption surface that adsorbs the workpiece, the communication channel, and the A communication hole communicating with the injection port and inclined with respect to the suction surface is provided,
A Bernoulli chuck characterized in that a stopper for supporting the edge of the workpiece is provided on the jetting direction side of the high-pressure gas jetted from the jetting port with respect to the jetting port. The injection port and the communication hole are formed in a flow path forming member separate from the suction holding plate,
The Bernoulli chuck according to claim 1, wherein the flow path forming member is embedded in the suction holding plate.   The Bernoulli chuck according to claim 1 or 2, wherein an inclination angle of the communication hole is set in a range of 8 to 20 degrees.   The flow path forming member has a first flow path forming member in which the directions of the injection ports are arranged in parallel to each other, and a predetermined opening outward with respect to the direction in which the injection ports of the first flow path forming member are directed. 4. The Bernoulli chuck according to claim 2, wherein the Bernoulli chuck is configured with an angle and a second flow path forming member arranged symmetrically outward from the first flow path forming member.   5. The Bernoulli chuck according to claim 4, wherein the second flow path forming member has an opening angle of each injection port set in a range of 10 to 40 degrees.   The back surface side ejection hole connected to the said communicating flow path is provided in the back surface on the side opposite to the said adsorption surface of the said adsorption | suction holding plate, The Claim 1 thru | or 5 characterized by the above-mentioned. Bernoulli Chuck.

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