JP2011151233A - Transfer mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer mechanism that holds and transfers a plate-like object without damaging its held surface. <P>SOLUTION: The transfer mechanism is equipped with, on holding surface 200 of a holding pad 20 constituting a suction holding mechanism 2: a suction recess 200a communicating with a suction source 25; and a fluid supply recess 200b formed annularly at a predetermined distance from an outer periphery of the suction recess 200a and communicating with a fluid supply source 28. A fluid layer 5 flowing between the holding surface 200 and an upper surface 4a of the plate-like object is formed 4 by supplying a fluid to the fluid supply recess 200b and also sucking the fluid from the suction recess 200a. The transfer mechanism sucks and holds the plate-like object 4 on the holding surface 200 of the holding pad 20 through the fluid layer 5. Even when the plate-like object is thick and large in mass to some extents, the transfer mechanism securely holds the plate-like object without damaging the held surface. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a transport mechanism that sucks and holds a plate-like object.

  In a semiconductor device manufacturing process, a semiconductor wafer on which a plurality of devices such as ICs and LSIs are formed is ground to a predetermined thickness by grinding the back surface thereof using a grinding device before being divided into individual devices. A grinding apparatus used for backside grinding of a semiconductor wafer includes a chuck table for sucking and holding the wafer, a grinding means for grinding the wafer sucked and held on the chuck table, and a wafer carry-in means for carrying a wafer before processing onto the chuck table. And wafer unloading means for unloading the wafer ground on the chuck table. The wafer carry-in means and the wafer carry-out means include a holding pad that sucks and holds the held surface (upper surface) of the wafer on the holding surface (lower surface), and a transfer movement unit that moves the holding pad to a predetermined position (for example, Patent Document 1).

JP 2003-282673 A

  However, if the suction holding pad of the wafer unloading means sucks and holds the ground wafer, there is a problem that the bending strength of the device is lowered. This problem is that the suction holding pad is made of a ceramic material, so that when the ground wafer is sucked and held, the suction holding pad comes into contact with the held surface of the wafer and damages the wafer. This is considered to be caused by lowering the bending strength of the device when divided into individual devices. Thus, the problem that the held surface is damaged occurs not only in the semiconductor wafer but also in other plate-like objects.

  The present invention has been made in view of the above facts, and its main technical problem is to realize a transport mechanism for a plate-shaped object that can be held and transported without damaging the held surface of the plate-shaped object. There is to do.

  The present invention relates to a transport mechanism for sucking and holding an upper surface of a plate-like object, and is composed of a suction holding mechanism for sucking and holding a plate-like object and a moving mechanism for moving the suction holding mechanism. The mechanism has a holding pad having a holding surface for holding a plate-like object, and the holding surface surrounds the suction recess and communicates with the suction source, and is annularly spaced from the outer periphery of the suction recess by a predetermined distance. And a fluid supply recess communicating with the fluid supply source, the holding surface of the holding pad is positioned facing the upper surface of the plate-like object, fluid is supplied to the fluid supply recess, and fluid is sucked from the suction recess Thus, a fluid layer that flows between the holding surface and the upper surface of the plate-like object is formed, and the plate-like object is sucked and held on the holding surface of the holding pad via the fluid layer. As the fluid supplied to the fluid supply recess, it is desirable to use a liquid, but other fluids such as air may be used.

  The conveying mechanism according to the present invention forms a fluid layer in which the holding surface of the holding pad sucks fluid and flows between the upper surface of the plate-like object, and the fluid layer without the contact between the holding pad and the plate-like object. Since the plate-like object is held on the holding surface of the holding pad through the plate, even if the plate-like object is thick to a certain extent and heavy in mass, the plate-like object can be reliably secured without damaging the held surface of the plate-like object. Can be held in. Also, if the fluid is a liquid, even if processing scraps are attached to the plate-shaped object, the processing scraps are not dried and firmly attached, so that it is difficult for the processing scraps to be removed. Can be prevented.

It is sectional drawing which shows schematically the structural example of a conveyance mechanism. It is a bottom view which shows a holding pad. It is sectional drawing which shows schematically the state before adsorb | sucking a plate-shaped object to a holding pad. It is sectional drawing which shows schematically the state which the fluid intervened between the holding pad and the plate-shaped object. It is sectional drawing which shows schematically the state in which the holding pad hold | maintained the plate-shaped object through the fluid layer. It is sectional drawing which expands and shows schematically the state which the holding pad hold | maintained the plate-shaped object via the fluid layer. It is sectional drawing which shows the 2nd structural example of a conveyance mechanism schematically.

  A transport mechanism 1 shown in FIG. 1 has a function of sucking and holding an upper surface of a plate-like object, and sucking and holding mechanism 2 for sucking and holding the plate-like object, and a moving mechanism for moving the suction and holding mechanism 2. 3.

  The suction holding mechanism 2 includes a holding pad 20, a plate member 21 having a plurality of through holes 21a penetrating the front and back surfaces, bolts 22 loosely fitted in the through holes 21a and screwed into the holding pads 20, and bolts 22 The coil spring 23 is wound around and is interposed between the holding pad 20 and the plate member 21. On the other hand, the moving mechanism 3 includes a shaft portion 30 connected to the plate member 21 and an arm portion (not shown) that moves the suction holding mechanism 2 by moving the shaft portion 30 up and down and horizontally.

  As shown in FIGS. 1 and 2, the holding pad 20 is formed in a substantially disk shape. The lower surface of the holding pad 20 is a flat holding surface 200 that holds a plate-like object. A suction recess 200a is formed at the center of the holding surface 200, and a suction recess 200a is located at a position surrounding the suction recess 200a. An annular fluid supply recess 200b is formed at a predetermined distance from the outer periphery of the ring. The holding pad 20 is preferably formed of an easily processable material having a certain degree of rigidity, such as a synthetic resin.

  The suction recess 200a is formed in a state of being recessed in a circular shape, for example, about several mm from the holding surface 200 at the center of the holding pad 20, and a suction path 201 penetrating in the thickness direction of the holding pad 20 is formed at the center. Has been. As shown in FIG. 1, the suction recess 200 a can communicate with either the suction source 25 or the fluid supply source 26 via the suction path 201 formed in the holding pad 20 and the switching valve 24. On the other hand, the fluid supply recess 200b is formed in an annularly depressed state at a predetermined distance from the outer periphery of the suction recess 200a, and the depth is about several millimeters deeper than the suction recess 200a. The suction recess 200a and the fluid supply recess 200b have a common center, and the outer periphery of the suction recess 200a and the inner periphery and outer periphery of the fluid supply recess 200b are concentric. The fluid supply recess 200 b communicates with the fluid supply source 28 through the fluid outflow passage 202 formed through the holding pad 20 in the thickness direction and the flow rate adjustment valve 27. The fluid supply sources 26 and 28 store a liquid such as water, for example.

  As shown in FIG. 3, when the transport mechanism 1 holds the plate-like object 4 to be transported, the holding surface 200 of the holding pad 20 is positioned at a position facing the upper surface 4 a of the plate-like object 4. Then, the switching valve 24 is set so that the suction path 201 and the fluid supply source 26 communicate with each other, the liquid 260 flows out from the suction recess 200a, and the liquid 280 also flows out from the fluid supply recess 200b. The whole is lowered in the direction of arrow A. Then, as shown in FIG. 4, the liquid is interposed between the upper surface 4 a of the plate-like object 4 and the holding pad 20. As the liquid, for example, water is used, but it is desirable to use carbonated water in order to prevent generation of static electricity. When the transport mechanism 1 is lowered, the thickness of the liquid between the holding surface 200 and the upper surface 4 a of the plate-like object 4 can be made substantially uniform by the elastic force of the coil spring 23.

  Next, as shown in FIG. 5, while continuing the supply of the liquid 280 from the fluid supply source 28 to the fluid supply recess 200b, the switching valve 24 is switched to connect the suction path 201 and the suction source 25, and the suction recess 200a. Apply negative pressure to Then, as shown in FIG. 6, the liquid 280 flowing out from the fluid supply recess 200b is sucked by the suction recess 200a, and the fluid layer 5 flowing in the horizontal direction between the upper surface 4a of the plate-like object 4 and the holding pad 20 is formed. It is formed. The plate-like object 4 is sucked and held by the holding surface 200 a of the holding pad 20 through the fluid layer 5 that flows. Since the fluid layer 5 is interposed between the holding pad 20 and the plate-like object 4 and the holding pad 20 does not directly contact the plate-like object 4, the plate-like object 4 is not damaged and the bending strength is not lowered. Further, even a plate-like object having a certain thickness and heavy mass can be held. The thickness of the fluid layer 5 at this time may be at least about several μm.

  By using a liquid as the fluid that flows out from the fluid supply recess 200b, when the plate-like product is a product after processing such as grinding, the processing waste is dried and firmly adheres to the upper surface 4a of the plate-like product 4. Can be prevented. In addition, air can be used as the fluid, but by using the liquid, the plate-like object 4 can be held more firmly by using the suction force and the surface tension of the liquid. While the liquid is kept flowing from the fluid supply recess 200b during the holding, the thickness of the fluid layer 5 is maintained substantially constant, so that the holding pad 20 and the plate-like object 4 do not come into contact with each other.

  In this way, the transport mechanism 1 ascends while the plate-like object 4 is held by the holding pad 20 via the fluid layer 5 and moves in the horizontal direction, so that the plate-like object 4 is conveyed to a desired position. Is done.

  As shown in FIG. 7, when the outer diameter of the holding pad 20 is smaller than the outer diameter of the plate-like object 6, the entire upper surface 6 a of the plate-like object 6 is not held. Becomes easier to move horizontally. Therefore, as shown in FIG. 7, three or more restricting means 29 for restricting the horizontal movement of the plate-like object 6 are arranged on the side of the holding pad 20, preferably at equal intervals. The restricting means 29 is, for example, a claw-like member having a cross-sectional shape obtained by inverting the L shape up and down. Thus, when the plate-like object 6 moves slightly in the horizontal direction, the inner peripheral surface 29a of the restricting means 29 and the side surface 6b of the plate-like object 6 come into contact with each other and the plate-like object 6 slides in the horizontal direction. It can be prevented and stably held by suction. Further, it is desirable that the regulating means 29 is disposed so as to be slidable in the horizontal direction or to be rotatable around a horizontal rotation axis.

  In the example shown in FIGS. 1 to 7, one suction recess 200 a and one fluid supply recess 200 b are formed. Alternatively, a plurality of these concentric circles may be alternately provided. In that case, the outermost peripheral portion is made a fluid supply concave portion so that the fluid can escape to the outer peripheral side.

  The type of plate-like object held in the transport mechanism 1 is not particularly limited, but the shape and cross-sectional area of the suction recess 200a and the liquid supply recess 200b can be appropriately changed according to the thickness, mass, etc. of the plate-like object. . Further, depending on the thickness, mass, etc. of the plate-like object, the negative pressure value in the suction recess 200a and the amount of water flowing out from the liquid supply recess 200b are also maintained constant and the thickness of the fluid layer 5 is maintained. It can adjust suitably so that it may become the balance hold | maintained by suction.

1: Transport mechanism 2: Suction holding mechanism 20: Holding pad 200: Holding surface 200a: Suction recess 200b: Liquid supply recess 201: Suction channel 202: Fluid outlet channel 21: Plate member 21a: Through hole 22: Bolt 23: Coil spring 24 : Switching valve 25: suction source 26: fluid supply source 260: liquid 27: flow rate adjusting valve 28: fluid supply source 280: liquid 29: regulating means 29a: inner peripheral surface 3: moving mechanism 30: shaft portion 4: plate-like object 4a: upper surface 5: fluid layer 6: plate-like object 6a: upper surface 6b: side surface

Claims (2)

A transport mechanism for sucking and holding the upper surface of a plate-shaped object,
A suction holding mechanism for sucking and holding a plate-like object and a moving mechanism for moving the suction holding mechanism;
The suction holding mechanism has a holding pad having a holding surface for holding a plate-like object,
The holding surface includes a suction recess that communicates with a suction source, and a fluid supply recess that surrounds the suction recess and is annularly formed at a predetermined distance from the outer periphery of the suction recess and communicates with a fluid supply source.
The holding surface of the holding pad is positioned so as to face the upper surface of the plate-like object, the fluid is supplied to the fluid supply recess and the fluid is sucked from the suction recess, whereby the holding surface and the plate-like object are A transport mechanism that forms a fluid layer flowing between the upper surface and the plate-like object by suction on the holding surface of the holding pad via the fluid layer. The transport mechanism according to claim 1, wherein the fluid supplied to the fluid supply recess is a liquid.

Images