Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H37/00—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00
  • F16H37/12—Gearings comprising primarily toothed or friction gearing, links or levers, and cams, or members of at least two of these types
  • F16H37/124—Gearings comprising primarily toothed or friction gearing, links or levers, and cams, or members of at least two of these types for interconverting rotary motion and reciprocating motion
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
  • B23Q7/00—Arrangements for handling work specially combined with or arranged in, or specially adapted for use in connection with, machine tools, e.g. for conveying, loading, positioning, discharging, sorting
  • B23Q7/04—Arrangements for handling work specially combined with or arranged in, or specially adapted for use in connection with, machine tools, e.g. for conveying, loading, positioning, discharging, sorting by means of grippers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
  • B25J9/00—Program-controlled manipulators
  • B25J9/10—Program-controlled manipulators characterised by positioning means for manipulator elements
  • B25J9/106—Program-controlled manipulators characterised by positioning means for manipulator elements with articulated links
  • B25J9/1065—Program-controlled manipulators characterised by positioning means for manipulator elements with articulated links with parallelograms
  • B25J9/107—Program-controlled manipulators characterised by positioning means for manipulator elements with articulated links with parallelograms of the froglegs type
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P72/00—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof
  • H10P72/70—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping
  • H10P72/76—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping using mechanical means, e.g. clamps or pinches
  • H10P72/7602—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping using mechanical means, e.g. clamps or pinches the wafers being placed on a robot blade or gripped by a gripper for conveyance
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H37/00—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00
  • F16H37/12—Gearings comprising primarily toothed or friction gearing, links or levers, and cams, or members of at least two of these types
  • F16H2037/128—Generating reciprocating motion by a planetary gear (ratio 2:1) using endless flexible members

Definitions

• the present invention relates to an improvement in apparatus arranged to move plate-like or wafer elements, such as semiconductor wafers utilized in the manufacture of semiconductor devices, and which must be transferred From one work station to another. Because of the need for maintaining cleanliness during the manufacturing processes for producing semiconductor wafers, and the need for enhancing the productivity of the operation, it is necessary to use an automated apparatus for handling the semiconductors and for transferring them from one work station to another. Cassettes have been used for handling a plurality of wafers for transferring the wafers from one operation to another. Previous methods of moving wafers to and from cassettes, for example belt drives, have proven to generate unacceptable amounts of contaminants; and therefore, the need has developed for other wafer-handling devices.
• the wafers must be moved into and out of the cassette by a mechanical transfer device which is sufficiently thin at the wafer-bearing end that it can enter into the relatively narrow space between adjacent wafers. It must then deposit or remove one wafer to or from the cassette without contacting or otherwise damaging either that wafer or those adjacent to it.
• the apparatus not include any mechanism which can generate particulate contaminants which can be deposited on any of the wafer surfaces. Because of the necessity for carefully locating wafers in proper position at the wafer work station, it is also a requirement that the transfer device be able to accurately engage a wafer and to accurately locate and transfer it. Background Art 5 One transfer device manufactured by Brooks
• Automation utilizes a pair of compound arms which are operated from one end by a motor and are connected at the opposite end to a wafer-holding spatula.
• This device has the disadvantage that the tCt distance over which it can transfer a wafer is limited to only the extended length of its arms. Further, this device relies upon intermeshing gears at the spatula end of the arms to synchronize the operation of the arms and to provide the desired
• an article transfer apparatus for moving an article, such as a semiconductor wafer, comprising a pair of compound arms and an article support means.
• Each of the compound arms is arranged for rotation in opposite directions about a first end thereof and carries the article support means at a second end thereof.
• Each of the compound arms comprises a first arm arranged to be drivingly rotated about a first end thereof, and a second arm having a first end rotatably mounted at the second end of the first arm.
• Each of the second arms is connected at the second end thereof to the article support means.
• Drive means is stationarily disposed at the first end of the first arm and driven means is drivingly connected to the first end of the second arm.
• Means is provided for drivingly connecting the driven means with the drive means with a speed ratio of 2:1 and whereby both move relatively in the same direction.
• Motor means is arranged for driving the compound arms.
• the present invention provides a transfer apparatus for moving an article such as a semiconductor wafer along a given path comprising a pair of compound arms arranged for rotation in opposite directions about respective parallel spaced axes at a first end and carrying at a second end a common article support means.
• Each of the compound arms comprises a first arm arranged to be drivingly rotated about the respective axis at a first end thereof, and a second arm having a first end rotatably mounted at the second end of the first arm.
• the second arm is pivotally connected at the second end thereof to the article support means.
• a drive means is stationarily disposed about the respective axis of the first arm and a driven means is movably mounted at the second end of the first arm and is drivingly connected to the first end of the second arm.
• Means is provided for drivingly connecting the driven means with the drive means with a speed ratio of 2:1 whereby both move relatively in. the same direction.
• Motor means is provided for driving the transfer-means, and means is provided for connecting the motor means to the first arms of the pair of compound arms coaxially along the respective axes and extending through the- stationary drive means.
• the present invention includes a drive belt as the connecting means in the arms and the drive means and the driven means are pulleys.
• FIG. 1 is a perspective exploded view of the transfer apparatus according to the present invention.
• FIGS. 2 and 3 are planned views of the apparatus according to the present invention showing the sequential operation thereof.
• the article transfer mechanism of the present invention is illustrated in a partially exploded perspective view in FIG. 1 and comprises a base member 10 having a pair of upright bearing shafts 12 and 14 on which the main frame portion 16 ride via bearing blocks 18, 20, and 22.
• a reversible stepper motor 24 is disposed on one side of the frame 16 and has an output shaft 26 carrying a worm gear 28 extending into the center of the frame.
• a pair of spaced, vertically parallel shafts 30 and 32 extend upwardly through the frame and are drivingly connected at the lower end to drive gears 34 and 36, respectively, which engage opposite sides of the worm gear 28.
• the upper end of the shafts extend above the top surface of the frame and are drivingly connected to the first ends of first arms 38 and 40 of compound arms 42 and 44. Journaled at the second end of the first arms are respective second arms 46 and 48, each of which are connected at the second end thereof to an article support means or spatula 50 which may be provided with three equispaced article engaging bosses 52.
• the drive means for arm 44 includes a first drive pulley 54 which is disposed about shaft 30 and is provided with a bearing 56 which permits the shaft to rotate freely with respect to the pulley 54.
• the lower surface of the pulley 54 is provided with a diametrically extending rib 58 which protrudes from the lower surface thereof and which engages a groove 60 provided in the upper surface of frame 16. The rib and groove cooperate to hold the p ⁇ lley 54 stationary while the shaft 30 and arm 38 are rotated.
• a driven pulley 62 is drivingly mounted on a shaft 64 which is arranged to rotate in the second end of the first arm 38. Suitable bearings 66 and 68 are provided there at for this purpose. The upper end of shaft 64 is drivingly connected to the first end of second arm 46.
• a drive belt 70 connects the drive pulley 54 with the driven pulley 62.
• a cover plate 72 is provided to the underside of arm 38 and is connected thereto with fastener members 74 to enclose the pulley and belt assembly.
• the drive pulley 54 has a diameter twice that of driven pulley 62 whereby the speed ratio of the driven pulley with respect to the drive pulley is 2:1, with both pulleys moving relatively in the same direction with respect to the first arm 38.
• This configuration provides, a movement of the second arms, 46 and 48, respectively, which are opposite to the movement of the first arms 38 and 40 and at a speed twice that of the first arms moving the spatula 50 along an accurate linear path.
• a lifting motor 76 is provided, which is also preferably a reversible stepper motor, the output shaft of which is connected through an eccentric 78 to the lower portion of the frame element 16. Upon rotation of the motor 76 the complete transfer mechanism is lifted by a predetermined amount which may be controlled by the eccentric and by the amount of rotation of the motor shaft.
• the transfer mechanism is also provided with a plurality of sensors 80 mounted on a support plate 82 located beneath one of the compound arms 44, the first arm of which, 40, is provided with a sensor-activating blade 84 on the lower surface thereof.
• This blade cooperates with the sensors 80 to generate a signal when the transfer mechanism is in one of. the three respective positions corresponding to the placement of the sensors.
• This signal can be used to calibrate the stepper motor for control of the stepper motor and to supply the necessary feedback to assure the accurate positioning of the article-carrying spatula 50.
• the main drive motor 24 is preferably a reversible stepper drive motor which can be accurately controlled by counting the number of revolutions, or portions"thereof, of the motor output shaft to accurately determine the position of the transfer arms and to accurately control the disposition of the arms with respect to the overall mechanism and the placement of the article carried thereby.
• the motor is reversible to drive the arms and the spatula in opposite directions to provide two-way transfer capabilities. Referring now to FIGS. 2 and 3 for a schematic illustration of the sequential operation of the transfer apparatus, the spatula may start in the right-most extended position as illustrated in phantom in FIG. 2. As the motor 24 drives the worm gear 28, gears 34 and 36 are rotated in opposite directions.
• the transfer apparatus of the present invention provides a travel distance for the article moved equal to twice the combined length of the first and second arms.
• the arms may also be driven in the opposite direction from that just described.
• the drive motor is of the stepper type, the arms can be accurately stopped at any desired position controlled by the stepper mechanism and control circuit.
• first and second arms may be understood by referring back to FIG. 1 and noting that as arm 38 rotates in a clockwise direction, the drive pulley 54 is held stationary by the engagement of rib 58 in slot 60.
• the belt 70 drives the driven pulley 62 and the shaft 64 and arm 46 connected thereto in a counter-clockwise direction.
• the driven pulley is driven at a speed twice the speed of the relative motion of the drive pulley with respect to the first arm 38.
• the first end of the second arm 46 effectively rotates 360 about its moving axis.
• the operation of the transfer mechanism of the present invention results in a smooth uniform linear travel of an article carried by the spatula 50 along a carefully and accurately controlled path.
• the distance of movement provided is twice that of similar prior art devices utilizing compound arms without the disadvantage of meshing gears in the region of the wafer surfaces. This motion is possible so long as the relative lengths of the respective arms are maintained such that the sum of the length of the first arms plus the distance between the drive shafts 30 and 32 is substantially equal to the sum of the length of the second arms plus the distance between the connection point of the second ends of the second arms at the spatula.
• This relationship permits the wafer to travel smoothly over center of the mechanism without binding or other adverse effects.
• the second arms 46 and 48 are simple bar members, having no complex mechanism therein and are made of relatively thin, flat materials. Likewise the connection between the second ends of arms 46 and 48 and the spatula 50 is
• the lifting motor provided by the transfer mechanism can accurately control the elevation of the mechanism whereby it can be accurately inserted into the space between adjacent wafers within a cassette
• the present invention provides an article transfer apparatus which simply and reliably transports an article over an accurate and predetermined path. Because of the interaction of the two compound arms, being driven
• Alternative embodiments of the present invention may include gears and drive chains for the drive and driven members in the first arms as well as a gear train provided that the drive and driven members are driven relatively in the same direction with respect to the direction of movement of the first arms. This is possible because these mechanisms, though not as clean as the belt drive, do not pass over any wafer surfaces which might be contaminated thereby.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Robotics (AREA)
• Container, Conveyance, Adherence, Positioning, Of Wafer (AREA)
• Manipulator (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=25343713

Family Applications (1)

Country Status (3)

Families Citing this family (13)

Family Cites Families (4)

• 1987
  • 1987-05-11 EP EP87903600A patent/EP0265517A1/de not_active Withdrawn
  • 1987-05-11 WO PCT/US1987/001085 patent/WO1987007078A1/en not_active Ceased
  • 1987-05-16 CN CN198787103643A patent/CN87103643A/zh active Pending

Non-Patent Citations (1)

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