JP2013157395A - Wafer cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer cassette which reduces the likelihood of the damage of wafers due to an impact applied during transportation.SOLUTION: A wafer casette (4, 4a) is used for housing multiple annular frames (F1), each of which is attached to a wafer (W1) or an adhesive tape and is integrated with the wafer. The wafer casette (4, 4a) includes: multiple housing shelves (42) formed on facing side plates (41a, 41b) and housing the wafer or the annular frame; an opening (O1) through which the wafer or the annular frame is carried in or out; a back support part (41c) supporting the wafer or the annular frame by back parts (E1, E1a, E1b); a restriction part (44) restricting the wafer or the annular frame housed in the housing shelf from being carried out; and elastic parts (43, 43a, 43b) disposed in the back support part. The wafer or the annular frame housed in the housing shelf is held by the restriction part and the elastic members.

Description

  The present invention relates to a wafer cassette that accommodates wafers, and more particularly to a wafer cassette that reduces the risk of wafer breakage during transport.

  In the manufacturing process of a semiconductor device, a dicing process for cutting and separating a wafer for each integrated circuit is performed. A wafer to be processed is fixed to an annular frame via an adhesive tape, accommodated in a transfer wafer cassette, and transferred to a cutting device. This wafer cassette generally has a configuration in which a pair of side plates having a plurality of horizontal grooves are opposed to each other (see, for example, Patent Document 1), and a frame extends from an insertion opening on one end side of the groove along each groove. Is inserted so that a plurality of wafers can be accommodated.

  A stopper may be provided on the wafer cassette in order to prevent the frame held in the groove from falling off when the wafer cassette is transported. The stopper is provided, for example, on the insertion port side of the groove serving as a frame conveyance path, and is selectively used as a closed position that blocks the groove and restricts the frame from being unloaded, and an open position where the restriction is released and the frame can be unloaded. It is comprised so that it can be positioned. If the stopper is positioned in the closed position after the frame is accommodated in the wafer cassette, it is possible to prevent the frame from falling off during the transfer of the wafer cassette.

JP-A-8-80989

  In the wafer cassette described above, the stopper is positioned at the closed position so as to close the groove serving as the frame transfer path. Absent. However, in recent years, wafers have a tendency to become larger (larger diameter), and as a result, there is an increased risk of wafer breakage due to factors different from frame pop-out.

  For example, when the frame is moved by an external force applied at the time of conveyance and the frame collides with the inner wall surface of the wafer cassette, an impact is applied to the wafer. Since the magnitude of the impact depends on the weight of the wafer, a very large impact is applied to the wafer whose weight is increased by increasing the diameter, and the risk of damage to the wafer increases.

  The present invention has been made in view of this point, and an object of the present invention is to provide a wafer cassette in which the risk of wafer breakage during transport is reduced.

  The wafer cassette of the present invention is a wafer cassette for accommodating a plurality of annular frames bonded to a wafer or an adhesive tape and integrated with the wafer, and accommodates a plurality of wafers or annular frames formed on opposing side plates. A storage shelf, an opening through which the wafer or the annular frame is taken in and out, a back stopper that supports the wafer or the annular frame at the back, and a regulation unit that regulates the unloading of the wafer or the annular frame stored in the storage shelf, An elastic member disposed on the back stopper, and the wafer or the annular frame accommodated in the accommodation shelf is sandwiched between the restricting portion and the elastic member.

  According to this configuration, the elastic member is disposed on the back stop portion that supports the wafer or the annular frame with the back portion, and the wafer or the annular frame is sandwiched between the regulating portion and the elastic member. The impact can be reduced by suppressing the movement of the wafer or the annular frame. For this reason, the fear of the damage of the wafer at the time of conveyance can be reduced.

  In the wafer cassette of the present invention, it is preferable that a support groove for supporting the wafer or the annular frame is formed in the elastic member at a height position equivalent to each of the storage shelves. According to this configuration, since the support groove for supporting the wafer or the annular frame is formed in the elastic member, the deflection of the wafer or the annular frame can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the wafer cassette which reduced the fear of the damage of the wafer at the time of conveyance can be provided.

It is a perspective view which shows the structural example of the cutting device with which the wafer cassette which concerns on Embodiment 1 is used. FIG. 3 is a schematic diagram illustrating a configuration example of a wafer cassette according to the first embodiment. 6 is a schematic diagram illustrating a configuration example of a wafer cassette according to a second embodiment. FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following, a configuration in which the wafer cassette of the present invention is applied to a cutting apparatus that cuts a wafer with a cutting blade will be described. However, a wafer processing apparatus to which the wafer cassette of the present invention is applied is limited to a cutting apparatus. Is not to be done. The wafer processing apparatus may be a laser processing apparatus that condenses laser light from a laser oscillator and processes the wafer. Further, other grinding apparatuses, polishing apparatuses, cleaning apparatuses, inspection apparatuses, die bonding apparatuses, and the like may be used.

(Embodiment 1)
FIG. 1 is a perspective view of a cutting apparatus in which the wafer cassette according to the first embodiment is used. The cutting apparatus 1 is configured so that the wafer W1 accommodated in the wafer cassette 4 can be unloaded by the drawing portion 51 and cut by the cutting unit 8.

  A wafer W1 to be processed by the cutting apparatus 1 has a substantially disk-shaped outer shape. The back side of the wafer W1 is attached to an annular frame (annular frame) F1 via a dicing tape (adhesive tape) T1. The surface of the wafer W1 is partitioned into a plurality of regions by streets (scheduled processing lines) arranged in a lattice pattern. In the wafer W1, a device (device pattern) is formed in each area partitioned by streets. Wafer W1 is cut along each street and divided into individual devices. Note that the processing target of the cutting apparatus 1 is not limited to a semiconductor wafer.

  The cutting apparatus 1 has a base 2 having a substantially flat top surface. The base 2 includes a base 21 having a substantially rectangular parallelepiped shape, and a projecting portion 22 projecting forward at some corners. An internal space is formed in the protruding portion 22, and the cassette elevator 3 is provided in the internal space so as to be movable up and down. On the upper surface of the cassette elevator 3, a wafer cassette 4 that houses the wafer W1 held by the frame F1 is placed. The configuration of the wafer cassette 4 will be described in detail later.

  A temporary placement mechanism 5 is provided on the upper surface of the base 21 at a position adjacent to the cassette elevator 3. The temporary placement mechanism 5 includes a drawing portion 51 and a pair of rails 52. The drawer 51 is configured to be movable in the first direction (Y-axis direction), and the wafer W1 (frame F1) positioned at the same height as the drawer 51 is moved to the rail 52 side by the vertical movement of the cassette elevator 3. Pull out. The rails 52 have a substantially L-shaped cross-sectional shape and are configured to be separated from each other in a second direction (X-axis direction) perpendicular to the first direction. The wafer W1 is drawn to a predetermined position on the rail 52 by the drawing portion 51, and is sandwiched in the second direction by the close proximity of the pair of rails 52. Thereby, the wafer W1 is aligned in the X-axis direction and the Y-axis direction.

  An opening extending in the X-axis direction is formed at a position adjacent to the temporary placement mechanism 5 of the base portion 21. The opening is covered with a table moving base 6 and a waterproof cover 61. Below the waterproof cover 61, an X-axis moving mechanism (not shown) is provided that can move the table moving base 6 in the X-axis direction. The X-axis movement mechanism includes a pair of guide rails parallel to the X-axis direction, an X-axis ball screw between the guide rails, and an X-axis pulse motor (not shown) that rotationally drives the X-axis ball screw. The table moving base 6 is connected to the X-axis ball screw via a nut portion (not shown), and is moved along the guide rail by the rotation of the X-axis ball screw.

  A chuck table 62 is provided on the table moving base 6. The chuck table 62 is formed in the shape of a small-diameter disk, and an adsorption surface 63 made of a porous ceramic material is provided at the center of the upper surface. The wafer W1 is held at a predetermined position on the chuck table 62 by sucking the wafer W1 from the back surface side on the suction surface 63. The chuck table 62 is supported so as to be rotatable around the Z axis on the table moving base 6 by a rotating mechanism (not shown). The wafer W1 aligned in the X-axis direction and the Y-axis direction by the temporary placement mechanism 5 is transferred to the chuck table 62 by transfer means (not shown).

  A table base 7 is disposed at a position adjacent to the table moving base 6 in the Y-axis direction. The table base 7 is provided with a Y-axis moving mechanism 71. The Y-axis moving mechanism 71 includes a pair of guide rails 72 parallel to the Y-axis direction, a Y-axis ball screw (not shown) between the guide rails 72, and a Y-axis pulse motor 73 that rotationally drives the Y-axis ball screw. A Y-axis table 74 is supported on the upper surface of the table base 7. The Y-axis table 74 includes a base portion 74a that is in contact with the table base 7 and a wall portion 74b that is erected with respect to the base portion 74a. The Y-axis table 74 is connected to the Y-axis ball screw via a nut portion (not shown) provided in the base portion 74a, and is moved along the guide rail 72 by the rotation of the Y-axis ball screw.

  A Z-axis moving mechanism 75 is provided on the wall 74 b of the Y-axis table 74. The Z-axis moving mechanism 75 is disposed on the front surface of the wall 74 b and is parallel to the Z-axis direction, a Z-axis ball screw 77 between the guide rails 76, and a Z-axis ball screw 77. A shaft pulse motor 78 is provided. A Z-axis table 79 is supported on the front surface of the wall 74b. The Z-axis table 79 includes a base portion 79a that is in contact with the wall portion 74b, and a wall portion 79b that protrudes forward (in the Y-axis direction) at the end of the base portion 79a. The Z-axis table 79 is connected to the Z-axis ball screw 77 through a nut portion provided on the base 79 a, and is moved along the guide rail 76 by the rotation of the Z-axis ball screw 77.

  The cutting unit 8 is supported on the wall 79 b of the Z-axis table 79 at a position above the chuck table 62. The cutting unit 8 includes a cylindrical spindle 81 and a cutting blade 82 that is detachably attached to one end of the spindle 81. A motor 83 is connected to the other end of the spindle 81 so that the cutting blade 82 attached to the spindle 81 can rotate. The wafer W1 is cut by rotating the cutting blade 82 and bringing it into contact with the wafer W1. The cutting unit 8 is provided with an imaging unit 9 adjacent to the cutting blade 82.

  A control unit (not shown) of the cutting apparatus 1 controls the X-axis moving mechanism and the Y-axis moving mechanism 71 based on the captured image captured by the imaging unit 9, and the cutting blade 82 of the cutting unit 8 is moved to the wafer W1. Align to the street. The wafer W1 aligned with the cutting blade 82 is cut by the rotated cutting blade 82 while spraying cutting water. The cut wafer W1 is picked up by a transfer means (not shown) and moved to the cleaning / drying mechanism 10 provided on the upper surface of the base 21.

  The cleaning / drying mechanism 10 includes a spinner table 101 that holds the wafer W <b> 1 in a cylindrical space formed on the base 2. The cleaning / drying mechanism 10 includes a cleaning liquid injection mechanism and a gas injection mechanism (both not shown). A rotating mechanism (not shown) is provided below the spinner table 101. The rotation mechanism has a spinner table motor (not shown) that applies a rotational force to the spinner table 101, and can rotate the spinner table 101 at a predetermined speed. When the wafer W1 is held on the spinner table 101, the spinner table 101 is rotated in the cylindrical space. In this state, the wafer W1 is cleaned by spraying the cleaning liquid from the cleaning liquid injection mechanism. After cleaning, the wafer W1 is dried by air jetted from the gas jetting mechanism.

  FIG. 2 is a schematic diagram illustrating a configuration example of the wafer cassette 4. In FIG. 2, for the sake of convenience of explanation, a part of the configuration is omitted and schematically shown.

  The cassette 4 includes a pair of side plates 41a and 41b arranged opposite to each other, and a back plate (back stopper) 41c provided on one end side of the side plates 41a and 41b, and on the other end side of the side plates 41a and 41b. It is open. The upper and lower ends of the side plate 41a and the upper and lower ends of the side plate 41b are connected by an upper plate 41d (not shown in FIG. 2, refer to FIG. 1) and a lower plate 41e, respectively. In addition, legs (not shown) are provided at the lower ends of the side plates 41 a and 41 b, and are placed between the lower ends of the side plates 41 a and 41 b and the upper surface of the cassette elevator 3 while being placed on the cassette elevator 3. There is a gap. As a result, a stopper (regulator) 44 described later can be rotated without contacting the upper surface of the cassette elevator 3.

  A plurality of horizontal plates 41f extending in the horizontal direction are provided at substantially equal intervals on the inner side surfaces of the side plates 41a and 41b, and a groove D1 is formed between the adjacent horizontal plates 41f. The grooves D1 are formed at substantially the same height in the side plates 41a and 41b, and a storage shelf 42 for storing the wafer W1 is configured by a set of the grooves D1 facing each other.

  On the other end side of the side plates 41a and 41b, the accommodation shelf 42 is provided with an opening O1 for loading or unloading the frame F1 (the frame F1 holding the wafer W1). By inserting the frame F1 from the opening O1 along the groove D1, the wafer W1 is accommodated in the accommodation shelf 42. Elastic members 43 (43a, 43b) extending in the vertical direction are provided on the inner surface of the back plate 41c. The elastic member 43 is made of a cushioning material such as rubber, and abuts against end portions (back portions) E1 (E1a, E1b) of the frame F1 accommodated in the accommodation shelf 42. The elastic member 43 prevents contact between the frame F1 and the inner surface of the back plate 41c, and alleviates the impact applied to the frame F1.

  On the side of the opening O1 of the side plate 41a, a stopper (regulating portion) 44 extending in a direction substantially perpendicular to the groove D1 is provided. The stopper 44 includes a vertical portion 44a extending in the vertical direction and a pair of horizontal portions 44b bent in the horizontal direction at both ends of the vertical portion 44a. Projecting portions 44c projecting toward the side plate 41a are provided at the tip portions of the pair of horizontal portions 44b, and the projecting portions 44c are recessed portions (not shown) provided at the upper and lower end portions of the side plate 41a. ) Is engaged. Thereby, the stopper 44 can be rotated with the protruding portion 44c as a fulcrum.

  The horizontal portion 44b has a predetermined length, and is configured so that the vertical portion 44a and the side plate 41a are not in contact with each other to prevent the stopper 44 from rotating. Further, as described above, a gap is formed between the lower ends of the side plates 41 a and 41 b and the upper surface of the cassette elevator 3 by the leg portions (not shown), and the lower end of the stopper 44 contacts the upper surface of the cassette elevator 3. It is supposed not to.

  The stopper 44 is selectively positioned at the closed position P1 where the carry-out or carry-in of the frame F1 is restricted and the open position P2 where the restriction is released, by rotating around the protrusion 44c. The closed position P1 is a position where the vertical portion 44a of the stopper 44 is disposed inside the side plate 41a, and the end portion E2 of the frame F1 accommodated in the accommodation shelf 42 and the vertical portion 44a are brought into contact with each other. When the stopper 44 is positioned at the closed position P <b> 1, the accommodated frame F <b> 1 is sandwiched between the stopper 44 and the elastic member 43. For this reason, in this state, the movement of the wafer W1 due to the external force is suppressed. Further, when the stopper 44 is positioned at the closed position P1, the accommodated frame F1 is not moved to the opening O1 side from the contact position between the vertical portion 44a and the end portion E2. That is, in this state, unloading or loading of the wafer W1 is restricted.

  The open position P2 is a position where the vertical portion 44a of the stopper 44 is disposed outside the side plate 41a and the contact between the frame F1 and the vertical portion 44a is released. At the open position P2, the vertical portion 44a is not disposed on the transfer path of the frame F1, and thus the wafer W1 can be transferred or transferred.

  At the upper end of the side plate 41a, a groove D2 is provided in which the upper horizontal portion 44b of the stopper 44 is engaged. The groove D2 is provided so as to define the closed position P1 of the stopper 44. When the upper horizontal portion 44b is engaged with the groove D2, the stopper 44 is positioned at the closed position P1. The stopper 44 is always urged downward by an urging member (not shown). Therefore, unless an upward force against the urging force of the urging member is applied, the engagement between the upper horizontal portion 44b and the groove D2 is maintained, and the state where the stopper 44 is positioned at the closed position P1 is maintained. The This urging member is provided at, for example, a lower protrusion (not shown).

  In the wafer cassette 4 configured as described above, after the frame F1 is accommodated in the accommodation shelf 42 through the opening O1, the stopper 44 is rotated to be positioned at the closed position P1, and the frame F1 is disposed with the stopper 44 and the elastic member. 43. In this state, since the frame F1 is held between the stopper 44 and the elastic member 43 without any gap, even if an external force is applied to the frame F1 due to the conveyance of the wafer cassette 4, the movement of the frame F1 is suppressed. Further, the impact on the frame F1 is mitigated by the elastic member 43.

  Thus, in the wafer cassette 4 according to the present embodiment, the elastic member 43 is disposed on the back plate (back stopper) 41c that supports the frame F1 (end (back) E1), and the frame F1 is a stopper. Since the (restricting portion) 44 and the elastic member 43 are sandwiched, the movement of the frame F1 due to an external force or the like during conveyance can be suppressed and the impact can be reduced. For this reason, the risk of damage to the wafer W1 during transfer can be reduced.

(Embodiment 2)
In the present embodiment, a wafer cassette having a mode different from that of the first embodiment will be described. FIG. 3 is a schematic diagram illustrating a configuration example of the wafer cassette 4a according to the second embodiment. 3, the same components as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted. Further, in FIG. 3, for the convenience of explanation, a part of the configuration is omitted and schematically shown.

  In the wafer cassette 4a, the elastic member 43 (43a, 43b) is provided with a plurality of grooves (support grooves) D3 (D3a, D3b) at height positions corresponding to the storage shelves 42. Specifically, the groove D3a and the groove D3b are provided at the same height position as the groove D1 facing each other in the side plates 41a and 41b. Thereby, the end E1a and the end E1b (both see FIG. 2) of the frame F1 accommodated in the accommodation shelf 42 are supported at the same height position by the groove D3a and the groove D3b.

  For example, in the wafer cassette 4 of the first embodiment, the frame F1 is supported by the horizontal plate 41f that forms the groove D1. That is, the frame F1 is supported only in the direction in which the horizontal plate 41f extends. For this reason, the frame F1 is difficult to bend downward in the A direction that is the extending direction of the horizontal plate 41f, but is downward in the B direction perpendicular to the A direction (the direction perpendicular to the extending direction of the horizontal plate 41f). It is easy to bend. In particular, when a wafer W1 having an increased diameter is used, the frame F1 is easily bent due to the weight of the wafer W1 and the frame F1.

  On the other hand, since the wafer cassette 4a according to the present embodiment includes the groove D3 that supports the frame F1 in the B direction, the bending of the frame F1 in the B direction can be suppressed. If the frame F1 bends in the B direction, the gap between the frame F1 and the side plates 41a and 41b increases, and the amount of movement of the frame F1 in the B direction increases. On the other hand, in the wafer cassette 4a according to the present embodiment, since the bending of the frame F1 is suppressed, the gap between the frame F1 and the side plates 41a and 41b is not increased, and the movement of the frame F1 in the B direction is suppressed. Is done. As a result, since the impact on the wafer W1 due to the movement of the frame F1 can be reduced, the risk of damage to the wafer W1 can be further reduced.

  In addition, this invention is not limited to description of the said embodiment, A various change can be implemented. For example, in the above-described embodiment, a wafer cassette that accommodates a wafer held in a frame (a frame in which a wafer is bonded to a dicing tape and integrated with the wafer) is illustrated, but the configuration of the wafer cassette is not limited thereto. I can't. The wafer cassette may directly contain wafers.

  In the above embodiment, the frame is sandwiched between the stopper and the elastic member without any gap in the state where the stopper is positioned at the closed position, but the frame has a slight gap between the stopper and the elastic member. It may be held in a held state. In this case, the frame is slightly moved by an external force at the time of transfer, but since the impact on the frame is absorbed by the elastic member, the impact on the wafer W1 is mitigated to reduce the risk of breakage. Can do.

  In the above-described embodiment, an elastic member made of a cushioning material such as rubber is applied. However, the material and shape of the elastic member are not particularly limited as long as the impact of the frame can be reduced. For example, a leaf spring made of a metal material or the like may be used as the elastic member. In the above embodiment, two elastic members are provided, but the number of elastic members is not particularly limited.

  Further, the wafer cassette of the above embodiment includes the leg portion at the lower portion of the side plate. However, the leg portion may not be provided as long as the stopper is rotatable. In addition, the configurations, methods, and the like according to the above-described embodiments can be changed as appropriate without departing from the scope of the object of the present invention.

  The present invention is useful as a wafer cassette for accommodating a wafer to be processed in a cutting device, a laser processing device, or the like.

1 Cutting Device 3 Cassette Elevator 4, 4a Wafer Cassette 41a, 41b Side Plate 41c Back Plate (Back Stop)
41d Upper plate 41e Lower plate 41f Horizontal plate 42 Storage shelf 43, 43a, 43b Elastic member 44 Stopper (regulator)
44a Vertical portion 44b Horizontal portion 44c Protruding portion D1, D2 groove D3, D3a, D3b groove (supporting groove)
E1, E1a, E1b End (back)
E2 end F1 frame (annular frame)
O1 opening P1 closed position P2 open position T1 dicing tape (adhesive tape)
W1 wafer

Claims (2)

A wafer cassette for accommodating a plurality of annular frames bonded to a wafer or an adhesive tape and integrated with a wafer,
A storage shelf for storing a plurality of wafers or annular frames formed on opposing side plates;
An opening for taking in and out the wafer or annular frame;
A back stop that supports the wafer or annular frame at the back;
A restricting portion for restricting unloading of the wafer or the annular frame accommodated in the accommodating shelf;
An elastic member disposed on the back stopper,
The wafer cassette accommodated in the accommodation shelf or the annular frame is sandwiched between the restricting portion and the elastic member. The wafer cassette according to claim 1, wherein the elastic member is formed with a support groove for supporting the wafer or the annular frame at a height position equivalent to each of the storage shelves.

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