JP2005166877A - Sheet stretcher - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet stretcher capable of surely stretching a sheet. <P>SOLUTION: The sheet stretcher stretches the wafer sheet 8 by lowering a holding plate 6 holding a wafer ring 7. In the sheet stretcher, a constitution in which a nut member 22 is housed in a recessed section 23 formed to the top face of the plate 6 under the state, in which plays in the vertical direction and the horizontal direction are permitted, and the top-face side is held by an upper hold-down member 24 is used as the connection system of the nut member 22 in a holding-plate drive mechanism in which a lifting-lowering driving shaft 12 with a feed screw section and the nut member 22 are combined. Accordingly, even when the driving shaft 12 is brought to the state in which its position is displaced slightly and its shaft is inclined to the nut member 22 by a mechanical error, the nut member 22 is lifted and lowered smoothly, and the wafer ring 7 can be pushed down uniformly by the holding plate 6. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a sheet expansion device that expands a sheet held on a wafer ring in a chip pickup device that picks up a semiconductor chip attached to a sheet.

  In a chip pickup device that picks up semiconductor chips supplied in a state of being attached to a sheet, a sheet expansion mechanism that expands the sheet in the horizontal direction in order to widen the interval between the semiconductor chips on the sheet and facilitate removal. It has. The expansion of the sheet is performed by holding the sheet spread on the wafer ring on the holding plate, moving the holding plate, and pressing the sheet to the cylindrical expanding ring.

As a drive mechanism for pressing the holding plate against the expanding ring in this sheet expansion mechanism, the feed screw that is screwed into a plurality of nut members arranged on the holding plate is simultaneously rotated by the rotation driving means to raise and lower the holding plate. The configuration is known (see, for example, Patent Document 1).
JP 10-270532 A

  The above-described seat expansion mechanism has the following problems due to the coupling form of the nut members in the configuration of the drive mechanism that presses the holding plate against the expand ring. That is, in the conventional device, each nut member is rigidly connected to the holding plate by means such as screw fastening, and the axial position and accuracy of the feed screw that is screwed into the nut member are correctly matched to each nut member. There was a need.

  However, it is not easy in terms of machine accuracy to fully support the rotation shaft provided with the feed screw so that it is aligned with the nut member. There may be an inclined state. In such a case, the nut member cannot be raised and lowered smoothly, and it has been difficult to stably perform the sheet expanding operation by pushing down the wafer ring by the holding plate.

  SUMMARY An advantage of some aspects of the invention is that it provides a seat expansion device capable of reliably performing seat expansion.

The sheet expanding apparatus of the present invention is a sheet expanding apparatus that expands the sheet held on a wafer ring in a chip pickup device that takes out a semiconductor chip attached on a sheet, and corresponds to an expansion range of the sheet. A holding plate for holding the wafer ring in a state of having a first opening of a size and having the extended range matched to the first opening; and the first opening provided below the holding plate And a base member having a second opening substantially concentrically arranged, and a cylinder which is provided on the base member so as to project upward and surround the second opening, and which can pass at least partially through the first opening. And a concave portion provided in an arrangement surrounding the first opening on the upper surface of the holding plate, and accommodated in a state where play in the vertical direction and / or horizontal direction is allowed in the concave portion. And a plurality of shaft members having a feed screw portion that is pivotally supported by the base member in an arrangement corresponding to the position of the nut member and screwed to the nut member. Rotation driving means for rotating the shaft member through a transmission mechanism, and lowering the holding plate, the sheet is pressed against the cylindrical portion to push down the wafer ring to expand the sheet. When the lower surface of the nut member comes into contact with the bottom surface portion of the recess and the holding plate is lifted to release the pressing of the sheet against the tubular portion, the upper surface of the nut member is Abuts against the retaining means.

  According to the present invention, as a coupling method of the nut member in the holding plate driving mechanism in which the shaft member having the feed screw portion and the nut member are combined, the nut member is vertically and / or horizontally placed in the recess provided on the upper surface of the holding plate. By using a configuration in which the play in the direction is allowed and the upper surface side is held by the retaining means, the shaft member is slightly displaced or inclined with respect to the nut member due to a mechanical error. Even in this case, the nut member can be smoothly raised and lowered, and the wafer ring can be uniformly pushed down by the holding plate, so that the sheet expanding operation can be performed stably.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a chip pickup device in which a sheet expanding apparatus according to an embodiment of the present invention is incorporated, FIG. 2 is a partial sectional view of the sheet expanding apparatus according to an embodiment of the present invention, and FIG. FIG. 4 is an explanatory diagram of the rotation transmission mechanism of the seat expansion device of the embodiment, and FIG. 4 is an operation explanatory diagram of the seat expansion device of the embodiment of the present invention.

  First, referring to FIG. 1, the structure of a chip pickup device in which a sheet extending device is incorporated will be described. A chip pickup device is a device for taking out a wafer-like semiconductor chip stuck on a sheet by a pickup head for each piece, and is arranged as a component supply unit for supplying a semiconductor chip in an electronic component mounting apparatus or the like. The In this chip pickup device, the sheet expanding device has a function of expanding the sheet held on the wafer ring so that the semiconductor chip can be easily taken out from the sheet.

  In FIG. 1, a support frame 2 is erected on an XY moving table 1, and a wafer holding table 3 is coupled to the upper end portion of the support frame 2 and held in a cantilever state. The wafer holding table 3 holds a wafer ring 7 on which a wafer sheet 8 (sheet) is stretched, and a plurality of semiconductor chips attached to the wafer sheet 8 in a wafer state by driving the XY moving table 1. Among these, an arbitrary semiconductor chip to be taken out can be positioned at a taking-out position by the nozzle 15 a of the pickup head 15.

  Below the wafer holding table 3, a ejector 13 is provided to extend in the horizontal direction by an inverted L-shaped support bracket 14 so as to coincide with the take-out position by the pickup head 15. When the semiconductor chip 9 is picked up from the wafer sheet 8 by lowering the pickup head 15, the semiconductor chip 9 to be picked up is pushed up from below by the ejector 13, and the semiconductor chip 9 is peeled off from the wafer sheet 8.

  The structure of the wafer holding table 3 will be described. The wafer holding table 3 has a structure in which a holding plate 6 is overlaid on a base member 4 coupled to the support frame 2. The holding plate 6 is a plate-like member provided with a circular opening 6a (first opening) at the center, and the size of the opening 6a is such that the semiconductor chip 9 is attached to the wafer sheet 8. The size corresponds to the extended range B (see FIG. 2). A wafer holding part 6b for accommodating and holding the wafer ring 7 is provided on the lower surface side of the holding plate 6. By inserting the wafer ring 7 into the wafer holding part 6b, the holding plate 6 The wafer ring 7 is held in a state where the extended range B of the wafer sheet 8 is matched with the opening 6a.

  Similarly, the base member 4 located below the holding plate 6 is a plate-like member, and an opening 4a (second opening) substantially concentrically arranged with the opening 6a is provided at the center of the base member 4. ing. A substantially cylindrical expanding ring 5 (cylindrical portion) is provided at the center of the upper surface of the base member 4 so as to surround the opening 4a and project upward. The outer diameter of the expand ring 5 is large enough to pass through the opening 6a, and the holding plate 6 holding the wafer ring 7 is lowered with respect to the base member 4 by the holding plate lifting mechanism described below. The wafer ring 7 is pushed down in a state where the upper end portion 5a of the expand ring 5 is pressed against the lower surface of the wafer sheet 8, whereby the wafer sheet 8 in the expansion range B is expanded.

  Next, the holding plate lifting mechanism will be described. In FIG. 1, a motor 11 is disposed at the end of the base member 4 in a posture in which the drive shaft protrudes to the lower surface side. The motor 11 transmits the rotation to a lifting drive shaft 12 (shaft member) for lifting and lowering the holding plate 6 via a transmission mechanism 10 disposed on the lower surface side of the base member 4. The elevating drive shaft 12 is provided in an arrangement corresponding to the position of the nut member 22 surrounding the opening 6a from the periphery, and is pivotally supported by the base member 4 via the bearing portion 16 as shown in FIG. A feed screw portion 12 a that is screwed into the nut member 22 is provided at the upper portion of the elevating drive shaft 12.

  Here, the screw type used for the feed screw portion 12a and the nut member 22 may be a combination of a ball screw and a ball screw nut. Here, the screw surfaces such as a triangular screw and a trapezoidal screw are in direct contact with each other. Screws are used. As a result, the feed screw portion 12a is screwed into the nut member 22 with some screw clearance, and play is allowed when the lifting operation is transmitted from the feed screw portion 12a to the nut member 22. In the transmission of the lifting operation, it is only necessary to transmit the driving force for extending the seat, and high positional accuracy is not required. Therefore, even if a screw that allows such play is used, there is no functional problem. Absent.

  The nut member 22 has a shape having a flange portion 22a projecting outward from the upper portion of the shaft portion 22b, and is accommodated in recesses 23 provided at four locations in an arrangement surrounding the opening 6a in the holding plate 6. By this, it is coupled to the holding plate 6. The concave portion 23 has a stepped shape in which the inner diameter of the upper portion 23a is larger than that of the lower portion 23b. The nut member 22 is accommodated with the flange portion 22a positioned in the upper portion 23a, and is provided on the upper surface of the holding plate 6. Further, the upper surface side is held by the upper pressing member 24 (a retaining means).

  As the upper pressing member 24, a simple member for pressing a small member such as a washer with a screw is used. By holding the upper surface side of the nut member 22 with such a simple upper pressing member 24 that can be easily removed, the nut member 22 can be easily removed from the feed screw portion 12a for maintenance and maintenance. It has a structure that improves workability during maintenance.

  Here, the nut member 22 is accommodated in the recess 23 in a state where play in the vertical and horizontal directions is allowed. That is, the depth of the upper portion 23a is set to be larger by the first allowance C1 than the thickness of the flange portion 22a, and the inner diameter of the lower portion 23b is set to be larger by the second allowance C2 than the outer diameter of the shaft portion 22b. Has been.

Next, the transmission mechanism 10 that transmits the rotation of the motor 11 to the lifting drive shaft 12 will be described. FIG. 3 shows an AA arrow view in FIG. The drive gear 17 coupled to the elevating drive shaft of the motor 11 meshes with meshing teeth 19b formed on the outer periphery of the gear ring 19 via an intermediate gear 18. The gear ring 19 is an annular member having an opening 19a (third opening) in the center, and is fitted into a fitting groove 19c formed on the inner diameter surface of the opening 19a as shown in FIG. It is rotatably supported by the base member 4 via a mating cam follower 21. In a state in which the gear ring 19 is rotatably held by the base member 4, the opening 19 a is substantially concentric with the opening 4 a, and the meshing tooth 19 b is a driven gear 20 coupled to the lower end of the elevating drive shaft 12. (Gear) meshes.

  Therefore, when the motor 11 is driven, the gear ring 19 is rotated through the drive gear 17 and the intermediate gear 18, and the driven gear 20 is further rotated. The gear ring 19 is a meshing conductive member that meshes with the intermediate gear 18 and transmits rotational torque to the lifting drive shaft 12, and the cam follower 21 serves as a holding means that rotatably holds the meshing transmission member on the base member 4. In addition, the motor 11 serves as a rotational drive unit that rotationally drives the lifting drive shaft 12 via the transmission mechanism 10.

  As an example of the transmission element constituting the transmission mechanism 10, in the present embodiment, an example is shown in which rotation is transmitted by meshing of gears such as spur gears, but meshing transmission other than this may be used. For example, it is possible to use an endlessly connected roller chain on the outer periphery of an annular member as the meshing transmission member, and mount the sprocket on the elevating drive shaft 12 instead of the driven gear 20 as a gear.

  In the rotational drive of the elevating drive shaft 12 via the transmission mechanism 10, no belt tension is applied to the elevating drive shaft 12 as in the case of rotational transmission using a toothed belt, and the gear ring 19 applies to the elevating drive shaft 12. Thus, rotational torque is transmitted without applying a large bending load. For this reason, the shaft diameter of the lift drive shaft 12 necessary for moving the holding plate 6 up and down for seat expansion and the rigidity of the bearing portion 16 that supports the lift drive shaft 12 are set to be small and compact. The mechanism can be realized.

  Next, the sheet expansion operation will be described with reference to FIG. FIG. 4A shows a state in which the motor 11 is driven in the direction in which the holding plate 6 descends to expand the seat. That is, by lowering the holding plate 6, the wafer ring 7 is lowered together with the holding plate 6. Then, in a state where the wafer sheet 8 is pressed against the upper end portion 5a of the expand ring 5, the extended range B (see FIG. 2) of the wafer sheet 8 is extended by further pressing down the wafer ring 7 with the lower surface of the holding plate 6. Then, the space between the semiconductor chips 9 in the wafer state that is expanded and adhered to the wafer sheet 8 is extended.

  When the seat is expanded, the lower surface of the flange portion 22a of the nut member 22 comes into contact with the bottom surface 23c (bottom surface portion) of the upper portion 23a of the concave portion 23, whereby the driving force for raising and lowering the holding plate 6 is transmitted. . In the transmission of the driving force, a screw type that allows play of the nut member 22 as described above is used for the combination of the feed screw portion 12a and the nut member 22, and the nut member 22 is vertically moved in the recess 23. Since the play is allowed in the horizontal direction and the horizontal direction, even if there is some error in the position of the elevating drive shaft 12 or the axis perpendicularity, the nut member 22 has the error. It is allowed to be displaced by the amount.

  Therefore, the lift drive shaft 12 can be operated in a plurality of times without causing an operation abnormality such as galling of the lift drive shaft 12 that occurs when the lift drive shaft 12 is rigidly connected to the holding plate 6 in the state where the mechanical error is present. An equal driving force can be transmitted to the holding plate 6 by the lifting drive shaft 12. Thereby, the holding plate 6 can push down the wafer ring 7 in a stable posture and stably perform sheet expansion.

FIG. 4B shows a state in which the motor 11 is driven in the direction in which the holding plate 6 is lifted to release the sheet expansion. That is, by raising the holding plate 6, the pressing of the wafer sheet 8 against the expanding ring 5 is gradually released. At this time, when the upper surface of the nut member 22 contacts the upper pressing member 24, a driving force for raising the holding plate 6 is transmitted. Since this driving force may be a small force that lifts the weight of the holding plate 6 or the wafer ring 7 or the like, the required driving force can be supported by the simple upper pressing member 24.

  As described above, as the holding plate drive mechanism, the driven gear is connected to the elevating drive shaft 12 having the feed screw portion 12a screwed to the nut member 22 connected to the holding plate 6 and having the driven gear 20 connected to the lower end. By transmitting the rotation by the gear ring 19 that meshes with the gear 20 and transmits the rotational torque to the lift drive shaft 12, a low-rigidity transmission mechanism can be employed. As a result, it is possible to realize a seat expansion apparatus that can reliably perform sheet expansion with a small and simple mechanism.

  Further, as a coupling method of the nut member 22 in the holding plate driving mechanism in which the lifting drive shaft 12 having the feed screw portion 12a and the nut member 22 are combined, the nut member 22 is moved up and down in the recess 23 provided on the upper surface of the holding plate 6. By using a configuration in which play in a horizontal and / or horizontal direction is permitted and the upper surface side is held by the upper pressing member 24, the lifting drive shaft is slightly displaced with respect to the nut member 22 due to a mechanical error. Even in the case where the shaft is inclined, the nut member 22 can be smoothly moved up and down, and the wafer ring 7 can be uniformly pushed down by the holding plate 6, so that the sheet expanding operation can be performed stably.

  In the above embodiment, an example is shown in which the sheet itself is stretched using a stretchable sheet as the wafer sheet 8 to which the chip 6 is adhered and held, but a non-expanding type that does not need to be expanded as a sheet. Even when a thing is used, the seat expansion apparatus shown in this embodiment can be applied.

  The sheet expanding apparatus of the present invention has an effect that the wafer ring can be uniformly pushed down by the holding plate and the sheet expanding operation can be stably performed, and is a chip pickup apparatus that picks up the semiconductor chip attached to the sheet. Is available.

The front view of the chip pick-up apparatus in which the sheet expansion apparatus of one embodiment of this invention was integrated The fragmentary sectional view of the sheet expansion device of one embodiment of the present invention Explanatory drawing of the rotation transmission mechanism of the sheet expansion apparatus of one embodiment of this invention Operation explanatory diagram of a seat expansion device according to an embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Wafer holding table 4 Base member 5 Expanding ring 6 Holding plate 7 Wafer ring 8 Wafer sheet 9 Semiconductor chip 10 Transmission mechanism 11 Motor 12 Lifting drive shaft 12a Feed screw part 19 Gear ring 20 Driven gear 21 Cam follower 22 Nut member 23 Recessed part 24 Holding member

Claims (1)

In a chip pickup device for taking out a semiconductor chip attached on a sheet, a sheet expansion device for expanding the sheet held on a wafer ring, wherein the first opening has a size corresponding to the expansion range of the sheet A holding plate that holds the wafer ring in a state in which the extended range is matched with the first opening, and a second plate that is provided below the holding plate and is substantially concentrically arranged with the first opening. A base member having an opening, a cylindrical part that surrounds the second opening and protrudes upward from the base member, and can pass at least partially through the first opening; and A concave portion provided in an arrangement surrounding the first opening on the upper surface, and accommodated in a state where play in the vertical direction and / or horizontal direction is allowed in the concave portion, and the upper surface side serves as a retaining means A nut member held by the base member, a plurality of shaft members having a feed screw portion that is pivotally supported by the base member in an arrangement corresponding to the position of the nut member and screwed into the nut member, and a transmission mechanism that transmits the shaft member. A rotation driving means for rotating and driving through
When the sheet is expanded by lowering the wafer ring in a state where the sheet is pressed against the cylindrical portion by lowering the holding plate, the lower surface of the nut member comes into contact with the bottom surface portion of the recess, The seat expanding device according to claim 1, wherein when the pressing of the sheet to the cylindrical portion is released by raising the holding plate, the upper surface of the nut member abuts on the retaining means.

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