JP2006137000A - Suction head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suction head capable of consistently and reliably sucking and holding even a mechanically brittle article by sufficiently reducing the impact when a suction face of the suction head is brought into contact with the article. <P>SOLUTION: A bellows is provided between a fixed part and a suction part to form a closed air chamber therebetween, and the article is sucked and held by adjusting the pressure in the air chamber in the bellows at a first pressure so that the suction part is almost lifted by the impact generated when the suction part is brought into contact with an article when a suction face of the suction part is brought into contact with the article, and at the second pressure higher than the first pressure so that a stopper part is not separated from the fixed part during the carriage and the stopper part of a movable member is abutted on the fixed part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a suction head, a suction device, and a transport device including the suction head for sucking and holding an article that is easily broken or has a suction mark such as a thin glass plate, a plastic sheet, a crystal plate, a ceramic plate, and a semiconductor wafer.

  When a relatively light article is transported or transferred to another place, it is widely performed that the article is sucked and carried by a suction head. For example, when the article holds a glass plate, a plastic sheet, a quartz plate, a ceramic plate, a semiconductor wafer, etc. made of a hard material with a thickness of several hundreds of μm or less, as an adsorption portion of the adsorption head, an adsorption surface and an article A suction pad or the like which is made of an elastic material such as rubber that easily absorbs the impact between the two and shaped to easily absorb the impact is used. However, when the suction part is made of an elastic material, an adsorption mark may remain on the article. When the adsorption mark adversely affects the subsequent processing, such a suction pad is not used, as shown in FIG. The adsorbing part 3 made of a hard resin material such as Teflon resin (registered trademark) may be used. In this case, since the adsorbing part 3 made of a hard resin material such as Teflon resin may be broken when it comes into contact with the fragile article 1 as described above, the adsorbing surface of the article 1 and the adsorbing part 3 during adsorption The gap A must be controlled with sufficiently high accuracy, and a highly accurate position control technique is required. Reference numeral 40 denotes a cradle for receiving the article 1 horizontally, which can be moved in the vertical direction by a vertical driving device (not shown) as required.

  Thus, in the prior art in which the gap A between the article 1 and the suction surface of the suction portion 3 must be controlled with sufficiently high accuracy during suction, the price of the transport device including the suction head 2 must be increased. . Moreover, since there is a gap A between the article 1 and the adsorption surface of the adsorption unit 3, the position of the article 1 may be shifted at the moment of adsorption, and the predetermined position of the article cannot be accurately adsorbed, The article could not be accurately transported or transferred to a predetermined position. In the case of an easily breakable article, even if a suction pad made of a soft material such as rubber is used, the suction surface of the suction head may be broken by an impact when it comes into contact with the article.

  Therefore, the main object of the present invention is to provide a suction head that does not break the article even when the suction surface of the suction head is brought into contact with a mechanically fragile article for suction holding.

  In order to solve the above problems, the present invention provides a suction head for sucking and holding the surface of a thin plate-like article such as a glass plate, a plastic sheet, a crystal plate, a ceramic plate, or a semiconductor wafer, and a fixing portion and the fixing A movable member that is slidably supported by the part, an adsorption part that is provided at one end of the movable member and is made of a hard resin material that can adsorb and hold the article, and is provided at the other end of the movable member, A stopper part that prevents the suction surface of the suction part from falling below a set level by abutting on the fixed part is provided between the fixed part and the suction part, and is closed between them. A bellows that forms an air chamber, and an air flow passage that is formed inside the movable member and supplies gas to the air chamber from the outside, and makes the suction surface of the suction portion contact the article. Sometimes When the article adsorbed on the adsorption surface of the adsorption unit is transported at a first pressure that causes the adsorption unit to be lifted by an impact force generated when contacting the article, the first pressure is higher than the first pressure. The pressure of the air chamber in the bellows is large so that the stopper portion of the movable member comes into contact with the fixed portion at a second pressure that is large enough that the stopper portion does not move away from the fixed portion during conveyance. Provided is a suction head characterized by adjusting and holding the article by suction.

  According to the present invention, since the impact when the suction surface of the suction head comes into contact with an article can be sufficiently reduced, even a mechanically brittle article can be stably held and transported stably.

  First, an embodiment of the suction head 2 of the present invention will be described with reference to FIG. In the present invention, in order to relieve a shock (impact) when the adsorbing part 3 comes into contact with a fragile plate-like article 1 such as a glass plate, a plastic sheet, a crystal, a ceramic plate, a semiconductor wafer, etc., the adsorbing part 3 This is based on the knowledge that an elastic body may be provided between the fixed portion and the fixed portion. Although a spring coil is generally used as an elastic body, there is a big problem that the spring coil alone is easily affected by gravity. In order to relieve the shock (impact) when coming into contact with the article 1, a spring coil with weak elastic force must be used. However, if the elastic force is weak, it is easy to expand and contract with a slight force, and high speed conveyance is difficult. There are various problems, for example, it is impossible to turn or reverse the transport mechanism horizontally.

  Therefore, in the present invention, a bellows is used as an elastic body, and an air chamber 11 closed inside the bellows is formed, and an adsorbing portion is attached to a movable member extending through the air chamber 11 of the bellows, so that the pressure of the air chamber 11 is selectively selected. When the suction head 2 contacts the article 1 from above and sucks it, the pressure of the air chamber 11 is set to a low first set value, and the stopper portion of the movable member is stably attached to the fixed portion. Make contact with a small pressure. When the suction head 2 includes a transport operation in which the suction head 2 rotates or turns at an angle in the transport process, and the suction head 2 sucks or delivers the article in a lateral direction or upside down, the pressure of the air chamber 11 is When the bellows is extended to a second set value that is larger than the first set value, and the suction surface of the suction head 2 comes into contact with the article 1, the stopper portion comes into contact with the fixed portion with the stable and small pressure. By adjusting the air pressure of the air chamber as described above, the impact of the article 1 can be reduced when the suction head 2 comes into contact with the article 1, and the conveying operation including turning, rotation, etc. can be performed stably and reliably. To do.

  First, an embodiment of the suction head 2 according to the present invention will be described with reference to FIG. In FIG. 1, reference numeral 3 denotes an adsorbing portion that adsorbs and holds a fragile plate-like article 1 such as a glass plate, a plastic sheet, a crystal, a ceramic plate, and a semiconductor wafer, and is substantially perpendicular to the adsorbing surface 3a. It has a plurality of suction passages 3b formed. The adsorbing portion 3 is made of a relatively hard material such as Teflon resin and is formed to be thin and have a small area within a range that does not affect the adsorbing function in order to reduce the weight.

  Reference numeral 4 denotes an airflow base portion that supports the suction portion 3, a suction path 4 a that communicates with each suction passage 3 b of the suction portion 3, an air flow path 4 b that supplies gas to an air chamber to be described later, and a central convex portion that extends into the air chamber 4c. An airflow pipe 20 of an airflow supply mechanism as shown in FIG. 2 is connected to the air flow path 4b. The airflow pipe is bifurcated in the middle, and in the middle of the branched airflow pipes 21 and 22, respectively. First and second on-off valves 23 and 24 and first and second flow rate adjusting valves 25 and 26 that are opened and closed by an electric signal are provided, respectively. An exhaust valve 27 is provided in the exhaust path extending from the branch point. The branched airflow pipes 21 and 22 are merged on the upstream side of the flow rate adjusting valves 25 and 26, and are connected to the gas supply device 29 through the stop valve 28. Here, the first flow rate adjustment valve 25 is set to a first flow rate in which the gas flow rate per unit time is smaller than that of the second flow rate adjustment valve 26, and the flow rate of the second flow rate adjustment valve 26 is higher than that. A large second flow rate is set. The first, second, and third on-off valves 23, 24, and 27 are electromagnetic valves that open and close by an electric signal to pass or block gas, and the exhaust valve 27 is the first and second on-off valves 23, 24. When either or both of these are open, they are closed, and when both the first and second on-off valves 23 and 24 are closed and no gas is supplied, the air chamber 11 is connected to the atmosphere. To do.

  Next, 5 is a first fixing portion attached to the transfer arm or transfer arm indicated by reference numeral 30 in FIG. 3, and 6 is a second fixing portion fixed to the first fixing member 5. Thus, the first fixing part 5 and the second fixing part 6 constitute a fixing member. The sliding part 7 which forms the cavity wall extended in the center longitudinal direction of the 2nd fixing | fixed part 6 is provided.

  A shaft portion 8 is slidably supported with respect to the sliding portion 7. A stopper portion 9 is attached to one end portion of the shaft portion or formed integrally therewith. As will be described later, the sliding portion 7 has a certain length and a small play with the shaft portion 8 so that the shaft portion 8 can be stably supported when the suction head 2 rotates or turns. It is preferred that Although not shown, a solid lubricant such as lubricating oil or grease may be applied between the sliding portion 7 and the shaft portion 8, and the sliding portion 7 or the shaft portion 8 may be applied. An annular groove serving as a lubricant reservoir may be provided at a specific position. The other end side of the shaft portion 8 is coupled to or integrally formed with the central convex portion 4 c of the airflow base portion 4. The stopper portion 9 can move in the space portion 5 a formed in the first fixing portion 5. Here, the shaft portion 8, the stopper portion 9, and the airflow base portion 4 constitute a movable member. Here, instead of the sliding portion, for example, a plurality of radial bearings (not shown) may be used, and the outer ring may be fitted to the fixing member, and the shaft portion 8 may be fitted into the inner ring.

  A commercially available bellows 10 is provided between the second fixing portion 6 and the airflow base portion 4 to form the closed air chamber 11 described above. The bellows 10 includes end plates 10a and 10b each having a hole of each size and shape in the center, and a bellows portion 10c fixed so that there is no air leakage. One end plate 10 a is fixed to the lower surface of the second fixing portion 6, and the other end plate 10 b is fixed to the annular upper surface of the airflow base portion 4, and the shaft portion 8 and the central convex portion 4 c of the airflow base portion 4. The joint part or the integral part corresponding thereto is in the air chamber 11. Here, the air flow path 4 b formed in the airflow base 4 communicates with the air chamber 11. In order to improve the airtightness of the air chamber 11, between the airflow base 4 and the end plate 10b of the bellows 10, between the second fixing portion 6 and the end plate 10a of the bellows 10, the first fixing portion 5 and O-rings 12a, 12b, and 12c are provided between the second fixing portion 6 and the second fixing portion 6, respectively.

  Next, the operation of the suction head 2 having such a structure will be described. In FIG. 1, the article 1 has already been adsorbed and held, but before the adsorbing and holding, the open / close valve is in a closed state, and thus the air chamber is connected to the atmosphere by the exhaust valve 27. In this state, the case where the stopper part 9 is in contact with the upper surface of the second fixing part 6 and the case where it is not in contact are considered. When the stopper portion 9 is in contact with the second fixed portion 6, the upward direction of the bellows 10 with respect to the sum of the weights of the movable portion including the shaft portion 8, the stopper portion 9, the airflow base portion 4 and the suction portion 3. When the stopper portion 9 is separated without contacting the second fixed portion 6, the weight of the movable member and the suction portion 3 is reversed, as opposed to the above. On the other hand, the pulling force of the bellows 10 is set so as to increase. Not only in spring coils, but also in bellows, the elastic force gradually decreases due to the influence of gravity and aging.Therefore, the latter is set to be the latter, and the decrease in the elastic force of the bellows is the flow rate of the gas supplied to the air chamber. It is preferable to compensate by adjusting.

  In the latter case, since the level of the lower surface of the adsorption unit 3, that is, the adsorption surface is difficult to be constant, the first opening / closing valve 23 is opened before the adsorption unit 3 contacts the article 1 to adjust the first flow rate. A gas having a first flow rate is supplied to the air chamber through the valve 25, the bellows 10 is extended, and the stopper portion 9 is brought into contact with the second fixing portion 6 with a substantially predetermined small pressure. The contact pressure at this time is determined by the brittleness of the article 1 or the difference between the sum of the weights of the movable member and the suction portion 2 and the upward pulling force of the bellows 10. In the same manner, the former also lowers the suction head 2 or raises the article 1 to bring the suction surface 3a into contact with the article 1, and operates a general suction device (not shown) in the contacted state to operate the suction path 4a and the suction. The article 1 is adsorbed through the passage 3b. Here, with respect to the step of lowering the suction head 2 or raising the article 1 to bring the suction surface 3a into contact with the article 1, the suction head 2 is made to approach at a high speed until the gap between the suction head 2 and the article 1 approaches a slight setting position. After that, if the method of approaching in two stages in which the approach speed is lowered is also used, the impact on the article 1 at the time of contact can be further reduced.

  A mechanism for transporting only an angle in the horizontal direction from the suction, for example, 90 degrees, will be described in detail with reference to FIGS. Reference numeral 30 denotes a transfer arm provided with the suction head 2 having the above-described structure at the tip portion, and the other end is fixed to the drive mechanism 31. The drive mechanism 31 has a rotary drive device 32 having a rotary plate 32a that can rotate a predetermined angle in the horizontal direction, that is, in a direction perpendicular to the paper surface, and a vertical drive device 33 that is mounted on the rotary plate 32a and moves up and down. It consists of. An arm support member 34 is fixed horizontally to the vertical movement device 33, and the transfer arm 30 is fixed horizontally to the arm support member 34. In FIG. 3, the illustration of the air flow supply mechanism as shown in FIG. 2 that supplies gas to the air chamber 11 of the suction head 2 is omitted.

  Next, the operation will be described with reference to FIGS. First, the rotation drive device 32 and the vertical movement device 33 of the drive mechanism 31 are at the basic position, and the transfer arm 30 is at the position indicated by the solid line. At the basic position, the first open / close valve 23 of FIG. 2 is opened by an electrical signal, and gas is supplied to the air chamber 11 in the bellows 10 through the first flow rate adjusting valve 25. At this time, the rod 33a of the vertical movement device 33 starts to move downward, and the suction surface 3a of the suction portion 3 contacts the article 1 at the position indicated by the chain line in FIG. Until this contact, the air pressure in the air chamber 11 becomes the first set value at a low level, and the stopper portion 9 is stably in contact with the upper surface of the second fixed portion 6 with a small applied pressure. Therefore, the suction surface 3a of the suction part 3 is at the set lower limit position in the suction head 2, and the suction surface 3a at the set lower limit position contacts the article 1 by the lowering of the rod 33a of the vertical movement device 33. At this time, when an impact force larger than a small pressure applied to the upper surface of the second fixing portion 6 by the stopper portion 9 is applied to the article, the suction portion 3 is lifted. Will not join. Then, suction is performed through the suction path 4 a almost simultaneously with this contact, and the article 1 is sucked by the suction portion 3 of the suction head 2.

  Next, the vertical movement device 33 starts to move and retracts the rod 33a by a predetermined stroke to shorten it, so that the suction head 2 is sucked and held after contacting the article 1, and then the rod 33a moves forward by a predetermined stroke. As a result, the article 1 is received from the cradle 40 and rises. At the same time, the rotation driving device 32 starts operating to rotate the rotating plate 32a in the horizontal direction by a predetermined angle. Accordingly, the vertical movement device 33, the arm support member 34, and the transfer arm 30 are turned by a predetermined angle, and the transfer arm 30 stops at the position indicated by the chain line in FIG. Thereafter, the vertical movement device 33 operates to extend the rod 33a by a set stroke to lower the suction head 2, and when the article 1 comes into contact with another cradle 40, the suction performed through the suction path 4a. Then, the suction unit 3 releases the article 1 and places it on the cradle 1. Thereafter, the transport arm 30 is raised again by the vertical movement device 33 and returned to the position indicated by the solid line by the rotation operation of the rotation drive device 32 to prepare for the next suction operation. According to this conveyance, as described above, when the suction unit 3 comes into contact with the article 1 and receives it from the cradle 40, and when the suction head 2 descends and the lower surface of the article 1 comes into contact with the cradle 40, the impact is applied. It can be reduced below the planned value.

  An example in which the front and back of the article 1 are reversed will be described with reference to FIG. In the case of this embodiment, the rotary plate 32a of the rotary drive device 32 in FIG. 3 is attached in the direction of the paper surface, that is, in the direction perpendicular to the rotary plate 32a shown in the drawing, and the vertical movement device in the same direction as shown in the drawing 33 is a fixed drive mechanism, or a commercially available single-axis robot is used. In the case of using the former driving mechanism, first, after the suction head 2 sucks and holds the article 1, the rotation driving device 32 operates to rotate the rotating plate extending in the paper surface direction, that is, the vertical direction by 90 degrees. Accordingly, the transport arm 30 and the suction head 2 rotate 90 degrees on the vertical plane and move from the Y1 position to the Y2 position.

  In this embodiment, after the suction head 2 sucks the article 1 as described above, the article 1 moves up by a predetermined stroke by the operation of the vertical movement device 33, and in this process, the second operation shown in FIG. The opening / closing valve 24 is opened, and a second set amount of gas larger than the first set amount is supplied to the air chamber 11 through the second flow rate adjusting valve 26. Accordingly, the pressure in the air chamber 11 increases to the second set value in a short time, and the stopper portion 9 is separated from the second fixed portion 6 in a state where the suction head 2 is moved from the position Y1 to the position Y2 and stopped. The pressure of the air chamber 11 is maintained more than the extent. The reason is that when the suction head 2 is at the position Y1, the weight of the movable portion including the shaft portion 8 is applied, but when it is at the position Y2, there is almost no influence of the weight. If the air pressure of 11 is not increased, the stopper portion 9 is separated from the second fixing portion 6, the horizontal position of the article 1 becomes unstable, and the delivery of the article 1 described later is hindered.

  Next, the rotation driving device 32 is operated to rotate the rotating plate spreading in the paper surface direction by 90 degrees to convey the suction head 2 and the article 1 to the position Y2. In the state where the suction head 2 and the article 1 are at the position Y2, as described above, the pressure of the air chamber 11 is held at the second set value higher than the first set value by the second opening / closing valve 24. The stopper portion 9 is in contact with the second fixing portion 6 so that the stopper portion 9 is not separated from the second fixing portion 6, and the article 1 is accurately held at the set position. On the other hand, when another suction head 2 ′ having the same structure as the suction head 2 stands by at the position Y3 corresponding to the suction head 2, the vertical movement as shown in FIG. 3 occurs when the suction head 2 moves to the position Y2. The device operates to advance and lengthen the arm by a predetermined stroke. Accordingly, the suction surface of the suction portion of the suction head 2 ′ contacts the back side of the article 1. At this time, since the pressure in the air chamber of the suction head 2 'is also at the second set value, when the suction surface advances by a predetermined stroke, the suction surface only advances to a position where it accurately contacts the back side of the article 1. It is.

  Thereafter, as described above, the suction head 2 ′ sucks the article 1, and after a slight delay, the suction head 2 stops the suction operation and releases the article 1, whereby the article 1 is held by the suction head 2 ′. The Along with this, the vertical movement device operates to retract the arm by a predetermined stroke to shorten the arm, and as described above, the rotation driving device operates to rotate the rotating plate 90 degrees counterclockwise. 2 'is conveyed above position Y4. Before and after this, the second on-off valve 24 is closed by the electrical signal, the exhaust valve 27 is opened to exhaust the gas in the air chamber 11, and the first on-off valve 23 is opened slightly later. The vertical movement device operates to advance and lengthen the arm 33a by a predetermined stroke, lower the suction head 2 ', and place the article 1 on another cradle 40 at the position Y4. When the article 1 comes into contact with another cradle, the air chamber 11 is at the first set value.

  In this embodiment, when the suction heads 2 and 2 ′ are oriented vertically downward, the air chamber pressure is set to a low first set value, and when the suction heads 2 and 2 ′ are oriented horizontally, a second set value larger than this is set. Therefore, when the suction surface 3a comes into contact with the article 1, the stopper portion 9 is in contact with the second fixed portion 6 with a stable and substantially constant small pressure, and therefore, the suction surfaces of the suction heads 2, 2 ′. The impact when 3a contacts the article 1 can be made sufficiently small.

  In addition to the above-described conveying method for delivering the article between the suction heads and inverting the article, the article is delivered by rotating 180 degrees to reduce the area occupied by the conveying mechanism, that is, directly above the position where the article is attracted. Various methods such as a method of reversing are possible, but when the suction head is in contact with the article regardless of the direction of the suction head, the stopper portion 9 is stably attached to the second fixing portion 6. The pressure of the air chamber in the bellows is adjusted so that the contact is made at a substantially constant small pressure. As a result, the impact when the suction surface of the suction head comes into contact with the article can be sufficiently reduced, and the article can be suctioned and held stably and reliably. In the case of performing a reversing operation in the vertical direction that rotates 180 degrees, the gravity of the movable portion is the same as the direction of the elastic force of the bellows 10, so that the stopper portion 9 is not separated from the second fixing portion 6. In addition, the pressure of the air chamber 11 needs to be set to a third set value that is higher than the second set value.

  In addition, if the movable member including the shaft portion 8 and the airflow gas portion 4 is lightened, the pressure in the air chamber 11 can be reduced and the response speed can be increased, so that the shaft portion is formed into a hollow pipe shape. It is desirable to consider the material, shape, size, etc. and make the movable member as light as possible. Here, since the vertical movement device may cause the rod to advance and retract in the horizontal direction, it may be called a linear drive device.

1 shows an embodiment of a suction head according to the present invention. An example of the gas supply mechanism used for this invention is shown. 1 shows an embodiment of a transport mechanism according to the present invention. Another embodiment of the transport mechanism according to the present invention is shown. An example of a conventional suction head is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 .. Goods 2 .... Adsorption head 3 .... Adsorption part 3a ... Adsorption surface 4 .... Air flow gas part 4a ... Vacuum path 4b ... Air flow path 5 .... First fixation part 6 .... Second fixation Part 7 ·· Sliding part 8 · Shaft part 9 · Stopper part 10 · Bellows 11 · · Air chamber 12 · · O-ring 20 · · Air flow pipes 21 and 22 · · Branched air flow pipes 23 and 24 · First and second on-off valves 25, 26, first and second flow rate adjusting valves 27, exhaust valve 28, stop valve 30, transfer arm 31, drive device 32, rotation drive device 32a ..Rotary plate 33. Vertical movement device 34. Arm support member

Claims (1)

In a suction head that sucks and holds the surface of a thin plate-like article such as a glass plate, plastic sheet, crystal plate, ceramic plate, semiconductor wafer,
A fixed part;
A movable member slidably supported on the fixed part;
An adsorbing portion made of a hard resin material provided at one end of the movable member and capable of adsorbing and holding the article;
A stopper portion that is provided at the other end of the movable member and prevents the suction surface of the suction portion from falling below a set level by contacting the fixed portion,
A bellows provided between the fixed part and the adsorbing part and forming a closed air chamber between them;
An air flow path formed inside the movable member for supplying gas from the outside to the air chamber;
With
When the suction surface of the suction portion is brought into contact with the article, the suction portion is sucked by the suction surface of the suction portion with a first pressure that causes the suction portion to be lifted by an impact force generated when contacting the article. When transporting the article, the stopper portion of the movable member is applied to the fixed portion at a second pressure that is greater than the first pressure and does not leave the stopper portion during the transport. An adsorption head, wherein the article is adsorbed and held by adjusting a pressure of the air chamber in the bellows so as to abut.