JP6551655B2 - Prober - Google Patents

Description

  The present invention relates to a prober, and more particularly to a prober that inspects the electrical characteristics of an electronic device provided on a wafer.

  In the semiconductor manufacturing process, thin disk-shaped wafers are subjected to various treatments to manufacture a plurality of chips having electronic devices. Each chip is inspected for electrical characteristics by a prober disclosed in Patent Document 1 and the like, and then separated into chips by a dicing apparatus.

  The prober holds the uninspected wafer stored in the storage box by vacuum suction using the suction portion of the transfer arm, takes out the wafer from the storage box by the transfer arm, and transfers the wafer to the pre-alignment apparatus disclosed in Patent Document 2 or the like. The pre-alignment apparatus has a table provided with a suction unit that holds the lower surface of the wafer by vacuum suction, and determines the position of an orientation flat (or notch) provided on the wafer with respect to the wafer held by suction by the table. Then, the wafer is rotated by the table so that the orientation flat is positioned in a predetermined direction, and the angular direction of the wafer is matched with the angular direction in the inspection unit.

  The wafer pre-aligned by the pre-alignment apparatus is held by suction by the suction unit of the transfer arm and transferred to the inspection unit.

  The inspection unit is configured to include a table, a probe, a tester, and the like. The inspection method using a prober is to hold the wafer by suction on a table, then contact the probe with the electrode pad of each chip and measure whether the signal output from the electrode of the chip is measured by a tester to operate normally Electrically inspect.

  The wafer after inspection is held by suction by the suction unit of the transfer arm, returned to the storage box, and stored.

Patent No. 3144925 gazette Patent No. 3178514 gazette

  As described above, in the prober, the transfer arm for transferring the wafer and the table of the pre-alignment unit hold the wafer by vacuum suction at the suction unit. When the wafer is taken out of the storage unit, the exact position of the wafer relative to the suction portion of the transfer arm is unknown, so several mm from the outer peripheral edge of the wafer so that the wafer can be suctioned even if it is misaligned by several mm. The part located inside is adsorbed.

  However, in a MEMS (Micro Electro Mechanical Systems) wafer, the electronic device may be destroyed by the pressure of vacuum adsorption. Therefore, the MEMS wafer cannot adsorb the manufacturing range of the electronic device, and can adsorb only the range of a portion located outside the manufacturing range and about several millimeters from the outer peripheral edge.

  In the conventional prober, since there is nothing corresponding to the MEMS wafer, the prober which can be processed without destroying the electronic device of the MEMS wafer in the transfer step and the pre-alignment step has been desired.

  Note that the MEMS wafer electronic device is an electronic device in which mechanical element parts, sensors, actuators, electronic circuits, and the like are integrated on a single semiconductor wafer.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a prober capable of carrying and pre-aligning a wafer without destroying an electronic device provided on the wafer. .

  According to one aspect of the prober of the present invention, in order to achieve the object of the present invention, a wafer is transferred from a storage unit storing a disk-shaped wafer to a pre-alignment unit, and the wafer pre-aligned by the pre-alignment unit is inspected. In the prober that inspects the wafer by the inspection unit and is inspected by the inspection unit, it is installed in the pre-alignment unit, and a conveying unit that supports the lower surface of the wafer and conveys the wafer from the storage unit to the pre-alignment unit. Chuck means, a centering means that is installed in the pre-alignment section and centers the center axis of the wafer on the center axis of the chuck means, and a first suction that is provided in the chuck means and holds the outer peripheral edge of the lower surface of the wafer by suction. Means.

  According to one aspect of the present invention, the transfer means transfers the wafer from the storage unit to the pre-alignment unit while supporting the lower surface of the wafer. At this time, since the wafer is not held by suction by the transfer means, the wafer is transferred without destruction of the electronic device in the wafer transfer process from the storage unit to the prealignment unit.

  In the pre-alignment process, the wafer is first centered by the centering means, and then the lower surface of the wafer is placed on the chuck means, and the outer peripheral edge of the lower surface of the wafer is sucked and held by the first suction means of the chuck means. Ru. At this time, since the wafer is already centered, the first adsorption means adsorbs and holds the outer peripheral edge that is out of the manufacturing range of the electronic device, that is, the range of a portion located inside several mm from the outer peripheral edge. . Thus, in the prealignment step, the wafer is prealigned without the electronic device being destroyed.

  Therefore, according to one embodiment of the present invention, the wafer can be transported and pre-aligned without destroying the electronic device provided on the wafer.

  In one aspect of the present invention, the pre-alignment unit is brought into contact with the outer peripheral edge portion of the lower surface of the wafer, receives the wafer transferred to the pre-alignment unit by the transfer unit, and is lowered at the position above the chuck unit. Lift means for placing the wafer on the chuck means by means of the centering means for centering the wafer placed on the chuck means by the lift means, or for centering the wafer received at a position above the chuck means by the lift means. Is preferred.

  According to one aspect of the present invention, the outer peripheral edge of the lower surface of the wafer that has been transferred to the position above the chuck means by the transfer means is brought into contact with the lift means. Thereby, the wafer is received by the lift means at a position above the chuck means. After this, the wafer is placed on the chuck means by the lowering operation of the lift means after being centered by the centering means. Thereafter, the outer peripheral edge portion outside the manufacturing range of the electronic device is sucked and held by the first sucking means.

  The wafer centering method by the centering means may center the wafer placed on the chuck means by the lift means, or may center the wafer received at a position above the chuck means by the lift means.

  In one aspect of the present invention, it is preferable that the pre-alignment unit rotates the chuck unit to rotate the wafer held by suction by the first suction unit to thereby pre-align the wafer.

  According to one aspect of the present invention, the wafer is rotated and pre-aligned with the outer peripheral edge portion of the lower surface thereof being sucked and held by the first sucking means. Therefore, the wafer being pre-aligned is not misaligned with respect to the chucking means, and therefore the precision of the pre-alignment is not affected.

  In one aspect of the present invention, the transfer means includes a second suction means for holding the outer peripheral edge of the lower surface of the wafer by suction, holding the prealigned wafer by suction using the second suction means, and transferring the wafer to the inspection unit. Is preferred.

  According to one aspect of the present invention, the pre-aligned wafer is transported to the inspection unit with the outer peripheral edge of the lower surface thereof being sucked and held by the second suction unit of the transport unit. Therefore, in the wafer transfer process from the pre-alignment unit to the inspection unit, the wafer is transferred without the electronic device being broken.

  In one aspect of the present invention, it is preferable that the inspection unit inspects the electrical performance of the electronic device provided on the pre-aligned wafer and excluding the outer peripheral edge of the wafer.

  According to an aspect of the present invention, the electrical performance of the electronic device is inspected for the wafer in the inspection unit.

  According to the prober of the present invention, the wafer can be transported and pre-aligned without destroying the electronic device provided on the wafer.

The whole perspective view showing the composition of the prober of an embodiment Side view of the inspection unit disposed inside the prober body of the prober of FIG. 1 Principal part enlarged perspective view showing the configuration of the pre-alignment unit An illustration in which the wafer is received by four pins above the subchuck An explanatory view showing a first centering method in a pre-alignment unit An explanatory view showing a second centering method in the pre-alignment unit An explanatory view showing a second centering method in the pre-alignment unit Explanatory drawing showing the operation of wafer pre-alignment An explanatory view in which the wafer after prealignment is lifted by the lift device

  Hereinafter, preferred embodiments of the prober according to the present invention will be described in detail with reference to the attached drawings.

  FIG. 1 is an overall perspective view showing the configuration of the prober 10 of the embodiment.

[Configuration of the prober 10]
The prober 10 includes a prober main body 12 and a loader unit 14 adjacent to the prober main body 12. In FIG. 1, the loader unit 14 is shown in a transparent manner to show a schematic structure inside the loader unit 14.

  FIG. 2 is a side view of the inspection unit 16 disposed inside the prober body 12 (see FIG. 1). A table 20 described later is shown as a vertical cross section.

<Configuration of inspection unit 16>
The inspection unit 16 is brought into contact with the table 20 having the holding surface 18 on which the disk-like wafer W is mounted, and an electronic device (not shown) of the wafer W mounted on the holding surface 18 of the table 20 And a probe 22 for inspecting the electrical characteristics of. In the embodiment, a MEMS wafer is exemplified as the wafer W, but is not limited thereto.

  The holding surface 18 of the table 20 is provided with an annular suction groove 19 centering on the central axis of the table 20. The suction groove 19 is connected to a vacuum source 23 via a vacuum path 21. By suctioning the air of the vacuum path 21 by the vacuum source 23, the wafer W placed on the holding surface 18 of the table 20 is vacuum adsorbed by the suction groove 19 and held by suction on the holding surface 18 of the table 20. The vacuum path 21 is provided with an electromagnetic valve 24 that opens the vacuum path 21 to the atmosphere, and the opening / closing operation of the electromagnetic valve 24 is controlled by the control unit 25.

  The table 20 is provided with a plurality of through holes 26 penetrating in the vertical direction, and, for example, three straight rod-like pins 28A, 28B, 28C are respectively inserted into the through holes 26. The pins 28 </ b> A, 28 </ b> B, 28 </ b> C are arranged at equal intervals along concentric circles centered on the central axis of the table 20.

  The lower ends of the pins 28A, 28B, 28C are connected to the horizontal surface of the horizontally arranged plate 30 below the table 20. The plate 30 is connected to a nut 36, the right end of which is screwed to the screw shaft 34 of the ball screw device 32.

  The screw shaft 34 is disposed in the vertical direction, and a linear motion guide 38 that guides the movement of the nut 36 in the vertical direction is connected to the nut 36. Furthermore, at the left end of the plate 30, a linear movement guide 40 for guiding the vertical movement of the plate 30 is provided.

  Therefore, the nut 36 can be moved in the vertical direction along the screw shaft 34 by driving the motor 42 of the ball screw device 32 to rotate the screw shaft 34 forward or backward. Therefore, when the nut 36 is moved upward, the three pins 28A, 28B and 28C are simultaneously moved up via the plate 30, and the upper end portions of the pins 28A, 28B and 28C are tables as indicated by the two-dot chain line. It protrudes upward from 20 holding surfaces 18. When the upper ends of the protruding pins 28A, 28B, 28C move to the receiving position of the wafer W, the driving of the motor 42 is stopped, and the uninspected wafer W transferred from the loader unit 14 in FIG. It is mounted on the upper end of 28B and 28C.

  Thereafter, the nut 36 is moved downward, and the upper ends of the three pins 28A, 28B, 28C are simultaneously sunk from the holding surface 18 of the table 20 as shown by the solid line. Thus, the wafer W is placed on the holding surface 18 of the table 20.

  The wafer W placed on the holding surface 18 is adsorbed and held on the holding surface 18 as described above, and then the electrical characteristics of the electronic device are inspected by the probe 22 and a tester (not shown). Since the inspection method of this electrical property is known, it is omitted here.

[Configuration and operation of loader unit 14]
The loader unit 14 shown in FIG. 1 includes a container (storage unit) 46 placed on a load port 44, a transfer arm (transfer means) 48, a pre-alignment unit 50, and the like.

  The uninspected wafer W stored in the container 46 (in FIG. 1, the wafer W is shown above the container 46 for the sake of clarity), the transport arm 48 is moved straight in the direction of arrow A. The lower surface is supported without adsorption. Thereafter, the wafer W is taken out of the container 46 by the linear movement of the transfer arm 48 in the direction of the arrow B, and is delivered to the pre-alignment unit 50.

  The pre-alignment unit 50 includes a sub-chuck (chuck means) 52, a pre-alignment sensor 54, a presence sensor 56, a lift device (lift means) 58, and a centering device (centering means) 60.

<Sub-chuck 52, Pre-alignment sensor 54, Presence sensor 56>
FIG. 3 is an essential part enlarged perspective view showing the configuration of the pre-alignment unit 50.

  A rotating portion 62 that rotates the sub chuck 52 about the rotation center shaft 52A is connected to the center portion of the lower surface of the sub chuck 52 that is formed in a rectangular shape in plan view. Further, at both ends in the longitudinal direction of the sub chuck 52, slit-like suction portions (first suction means) 64 that hold the outer peripheral edge portion of the lower surface of the wafer W by vacuum suction are provided. The suction portion 64 is formed in an arc shape, and the radius of curvature thereof is set to be substantially the same as the radius of curvature of the outer peripheral edge portion of the wafer W. The wafer W is rotated along with the sub-chuck 52 by the rotating unit 62 after the outer peripheral edge of the lower surface thereof is adsorbed and held by the adsorbing unit 64.

  The in-stock sensor 56 detects the presence / absence of the wafer W supported by the transfer arm 48 without suction. The rotating unit 62 is driven to rotate after the load sensor 56 detects the wafer W and the outer peripheral edge of the lower surface of the wafer W is sucked and held by the sucking unit 64. That is, since the transfer arm 48 supports and transfers the wafer W without suction, a load sensor 56 for detecting the wafer W is required.

  The pre-alignment sensor 54 detects the position of the orientation flat (not shown) or notch (not shown) of the wafer W by the rotating operation of the wafer W by the rotating unit 62. Thereby, the wafer W is positioned. That is, the wafer W is rotated to a target angle based on the position of the orientation flat or notch formed on the wafer W and positioned at a predetermined position. With the above operation, the pre-alignment process is completed.

<Lift device 58, centering device 60>
Prior to the pre-alignment process, the wafer W is centered with respect to the sub chuck 52 by the lift device 58 and the centering device 60. That is, the center axis WA of the wafer W is centered (also referred to as centering) on the rotation center axis 52A of the sub chuck 52.

  The lift device 58 includes four pins 66 that are moved up and down all at once by a lifting mechanism (not shown). The four pins 66 are installed at a position where a square center of gravity centering on the four pins 66 coincides with the rotation center axis 52 </ b> A of the sub chuck 52. Further, when the wafer W is transported to the upper position of the sub chuck 52 by the transport arm 48, the four pins 66 are moved up simultaneously, and the upper surface of the four raised pins 66 is the lower surface of the wafer W. The outer peripheral edge of the is abutted. As a result, the wafer W transferred by the transfer arm 48 is received by the four pins 66 at a position above the sub chuck 52 as shown in FIG.

  The centering device 60 includes four pushers 68 that are simultaneously moved forward and backward in the horizontal direction with respect to the rotation center shaft 52A of the sub chuck 52 by an advancing / retreating mechanism (not shown). Further, the four pushers 68 are installed at positions where the center of gravity of a quadrangle having four pushers 68 as corners coincides with the rotation center axis 52 A of the sub chuck 52.

  In the first centering method, as shown in FIG. 4, with the outer peripheral edge of the lower surface of the wafer W placed on the upper end of the four pins 66, the four pins 66 are moved downward as shown in FIG. The wafer W is placed on the sub chuck 52. Thereafter, the four pushers 68 are moved forward toward the rotation center shaft 52 </ b> A of the sub chuck 52, and the peripheral portion of the wafer W is pushed by the pushers 68. Thus, the wafer W is centered while sliding while being placed on the sub chuck 52.

  When centering is completed, the four pushers 68 are retracted with respect to the rotation center shaft 52A of the sub chuck 52 and returned to the centering start position.

  In the second centering method, as shown in FIG. 4, the outer peripheral edge of the lower surface of the wafer W is placed on the upper ends of the four pins 66, and the four pushers 68 are attached to the sub chuck 52 as shown in FIG. Are moved toward the rotation center axis 52A, and the periphery of the wafer W is pushed by the pusher 68. Thus, the wafer W is centered while sliding while being placed on the upper end portions of the four pins 66.

  When centering is completed, as shown in FIG. 7, the four pushers 68 are retracted and moved with respect to the rotation center shaft 52A of the sub chuck 52, and are returned to the centering start position. At the same time as or after the end of the return operation, the four pins 66 are moved downward to place the centered wafer W on the sub-chuck 52.

  After the wafer W is centered on the sub-chuck 52 by the first or second centering method, the suction portion 64 of the sub-chuck 52 holds the outer peripheral edge of the lower surface of the wafer W by vacuum suction and holds the above-described pre-alignment of the wafer W. Is performed using the prealignment sensor 54 as shown in FIG.

  The wafer W for which the pre-alignment process is completed is lifted to the receiving position by the lifting operation of the four pins 66 of the lift device 58 as shown in FIG. Thereafter, the outer peripheral edge portion of the lower surface of the wafer W is held by suction by the slit-like suction unit (second suction unit) 70 of the transfer arm 48. The suction portion 70 is formed in an arc shape, and the radius of curvature thereof is set equal to the radius of curvature of the outer peripheral edge portion of the wafer W.

  Thereafter, as shown in FIG. 1, the wafer W is horizontally rotated 90 degrees toward the prober main body 12 by the transfer arm 48, and then carried into the prober main body 12 by the linear movement of the transfer arm 48 in the arrow C direction. , And passed to the upper ends of the pins 28A to 28C indicated by the two-dot chain line in FIG. Thereafter, the transfer arm 48 is linearly moved in the direction of arrow D in FIG. 1 and returned to the original initial position.

  When the inspection by the probe 22 in FIG. 2 is completed, the transfer arm 48 is moved again to the prober main body 12 by the straight movement operation in the direction of arrow C in order to receive the wafer W that has been inspected. Thereafter, the wafer W after the inspection is sucked and held at the outer peripheral edge portion of the lower surface thereof by the suction portion 70 of the transfer arm 48 and returned to the container 46 by the operation of the transfer arm 48 and stored.

[Features of the prober 10]
The first feature is that the wafer W is transferred from the container 46 to the pre-alignment unit 50 in a state where the lower surface of the wafer W is supported without suction by the transfer arm 48 as shown in FIG.

  At this time, since the wafer W is not adsorbed and held by the suction unit 70 of the transfer arm 48, in the wafer transfer process from the container 46 to the prealignment unit 50, the wafer is not broken by the suction pressure. W can be transported.

  The second feature is that, as shown in FIGS. 4 to 7, after the wafer W is centered by the four pushers 68 of the centering device 60 in the pre-alignment step, the lower surface of the wafer W is attracted by the suction portion 64 of the sub chuck 52. It is to hold the outer peripheral portion by suction.

  At this time, since the wafer W is already centered, the suction unit 64 sucks and holds the outer peripheral edge that is out of the manufacturing range of the electronic device, that is, the range of the portion positioned about several millimeters inside from the outer peripheral edge. . Therefore, in the pre-alignment process, the wafer is pre-aligned without destroying the electronic device.

  Therefore, according to the prober 10 of the embodiment, the wafer W can be transported and pre-aligned without destroying the electronic device provided on the wafer W.

  The third feature is that, like the second centering method shown in FIGS. 6 and 7, the outer peripheral edge of the lower surface of the wafer W transferred to the position above the sub chuck 52 by the transfer arm 48 is raised. The wafer W is received by the four pins 66 and in this state, the wafer W is centered by the four pushers 68.

  On the other hand, as in the first centering method shown in FIG. 5, the wafer W may be centered by the four pushers 68 while the wafer W is placed on the sub chuck 52. Since the manufacturing range of the electronic device on the lower surface is rubbed by the sub chuck 52, the electronic device may be affected.

  On the other hand, according to the second centering method, the wafer W is centered with the outer peripheral edge which is out of the manufacturing range of the electronic device supported by the four pins 66, thus affecting the electronic device. It has the advantage of not giving it.

  The fourth feature is that, as shown in FIG. 8, the outer peripheral edge of the lower surface of the wafer W is rotated and pre-aligned in a state of being held by suction by the suction portion 64 of the sub chuck 52. As a result, the wafer W being subjected to the prealignment is not misaligned with respect to the sub chuck 52, and therefore, the accuracy of the prealignment is not affected.

  The fifth feature is that the outer peripheral edge of the lower surface of the prealigned wafer is held by suction by the suction unit 70 of the transfer arm 48 and transferred to the inspection unit 16 as shown in FIG. Thus, in the wafer transfer process from the prealignment unit 50 to the inspection unit 16, the wafer W is transferred without the electronic device being broken.

  The inspection unit 16 inspects the electrical performance of the electronic device provided in the pre-aligned wafer W and the portion of the wafer W excluding the outer peripheral edge.

  As mentioned above, although the prober 10 which concerns on embodiment was demonstrated in detail, this invention is not limited to the above example, In the range which does not deviate from the summary of this invention, you may perform various improvement and deformation Of course.

W: Wafer, 10: Prober, 12: Prober body, 14: Loader unit, 16: Inspection unit, 18: Holding surface, 19: Adsorption groove, 20: Table, 21: Vacuum path, 22: Probe, 23: Vacuum source , 24: electromagnetic valve, 25: control unit, 26: through hole, 28A, 28B, 28C: pin, 30: plate, 32: ball screw device, 34: screw shaft, 36: nut, 38: linear guide, 40 ... Linear motion guide, 42 ... Motor, 44 ... Load port, 46 ... Container, 48 ... Transport arm, 50 ... Pre-alignment unit, 52 ... Sub-chuck, 54 ... Pre-alignment sensor, 56 ... Load sensor, 58 ... Lift device , 60 ... Centering device, 62 ... Rotating part, 64 ... Suction part, 66 ... Pin, 68 ... Pusher, 70 ... Suction part

Claims (5)

The prober transports the wafer to the pre-alignment unit from the storage unit in which the disk-like wafer is stored, transports the wafer pre-aligned by the pre-alignment unit to the inspection unit, and inspects the wafer by the inspection unit ,
Conveying means for supporting the lower surface of the wafer and conveying the wafer from the storage unit to the pre-alignment unit;
Chuck means installed in the pre-alignment unit and on which the lower surface of the wafer is placed;
A first suction means provided in the chuck means for sucking and holding the outer peripheral edge of the lower surface of the wafer;
Centering means disposed in the pre-alignment unit and centering the central axis of the wafer on the central axis of the chucking means before the first adsorption means adsorbs and holds the outer peripheral edge of the lower surface of the wafer;
With
The pre-alignment unit is brought into contact with the outer peripheral edge of the lower surface of the wafer, and the wafer transferred to the pre-alignment unit by the transfer unit is received at a position above the chuck unit and lowered. A lift unit for mounting the wafer on the chuck unit;
Said centering means, said centering the wafer placed on the chuck means, or centering the wafer received in the upper position of the chuck means by said lifting means by said lifting means, flop rover. The prober transports the wafer to the pre-alignment unit from the storage unit in which the disk-like wafer is stored, transports the wafer pre-aligned by the pre-alignment unit to the inspection unit, and inspects the wafer by the inspection unit ,
Conveying means for supporting the lower surface of the wafer and conveying the wafer from the storage unit to the pre-alignment unit;
Chuck means installed in the pre-alignment unit and on which the lower surface of the wafer is placed;
Centering means installed in the pre-alignment section and centering the central axis of the wafer on the central axis of the chuck means;
A first suction means provided in the chuck means for sucking and holding the outer peripheral edge of the lower surface of the wafer;
Equipped with
The pre-alignment unit is brought into contact with the outer peripheral edge of the lower surface of the wafer, and the wafer transferred to the pre-alignment unit by the transfer unit is received at a position above the chuck unit and lowered. A lift unit for mounting the wafer on the chuck unit;
The prober, wherein the centering means centers the wafer placed on the chuck means by the lift means, or centers the wafer received at a position above the chuck means by the lift means. The pre-alignment unit rotates the chuck means to rotate the wafer held by suction by the first suction means to pre-align the wafer;
The prober according to claim 1 or 2 . The transport means comprises second suction means for sucking and holding the outer peripheral edge of the lower surface of the wafer,
The pre-aligned wafer is sucked and held by the second sucking means and transferred to the inspection unit.
The prober according to any one of claims 1 to 3 . The inspection unit is the pre-aligned wafer, and inspects the electrical performance of an electronic device provided in a portion excluding the outer peripheral edge of the wafer.
The prober according to any one of claims 1 to 4 .

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