JP2001287141A - Grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform high accurate grinding by stably supporting a holding table for holding a work piece by a method capable of keeping high throughput without causing heaviness or largeness, in the grinding device for grinding surfaces of the work piece such as a semiconductive wafer. SOLUTION: The grinding device 10 comprises the holding table 17 for holding the work piece, a holding table positioning means 18 that includes at least a carry-in region used for carrying the work piece to the holding table 17, a grinding region used for grinding the work piece held by the holding table 17, and a delivery region used for delivering the work piece from the holding table, and positioning the holding table 17 to the carry-in region, the grinding region, or the delivery region, and a support base 41 for supporting the holding table 17 positioned to the grinding region by the holding table positioning means 18. The holding table 17 is supported by the support base 41 with high rigidity during grinding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a grinding apparatus for grinding a surface of a workpiece such as a semiconductor wafer.

[0002]

2. Description of the Related Art For example, a grinding apparatus 80 shown in FIG.
The apparatus includes a holding table 81 for holding a workpiece, grinding means 82 disposed opposite to the holding table 81, and a turntable 83 for holding and rotating the holding table 81.

When grinding a workpiece, first, the workpiece is loaded into a holding table 81 and held in a loading area (not shown). Next, by appropriately rotating the turntable 83, the holding table 81 is
, A grinding wheel 85 having a grinding wheel 84 fixed thereto is lowered while rotating to apply a pressing force to the workpiece to perform grinding.
After the grinding is completed, the holding table 81 is positioned in a carry-out area (not shown) by the rotation of the turntable 83, and the ground work is carried out here.

[0004]

As described above, the holding table 81 for holding the workpiece is supported by the turntable 83, and in this state, the grinding means 82
As a result, the pressing force is applied from above to perform the grinding, so that a considerable load is applied to the turntable 83 during the grinding, causing bending. Therefore, there is a problem in that an error occurs in the height and angle of the holding table 81 due to the bending of the turntable 83, and as a result, high-precision grinding cannot be performed.

On the other hand, if it is attempted to increase the rigidity of the turntable 83 itself in order to ensure high-precision grinding, there is a problem that the weight increases, the apparatus becomes large, and the cost increases.

[0006] There is also provided a grinding apparatus in which a holding table is fixed and a workpiece is conveyed only without using a turntable. In this case, a holding table for the workpiece is provided. Since the workpiece must be handled carefully so as not to damage the workpiece when it is loaded into and unloaded from the holding table, there is a problem in that it takes a long time to transport and the throughput is reduced.

Further, in this case, since the holding table is fixed directly below the grinding wheel, there is a problem that cleaning of the holding table is difficult.

As described above, in the grinding apparatus, high-precision grinding can be performed without increasing the weight and the size of the apparatus, while maintaining high throughput and easy cleaning of the holding table. In particular, there is a problem to be solved.

[0009]

SUMMARY OF THE INVENTION As specific means for solving the above-mentioned problems, the present invention provides a holding table for holding a workpiece, a loading area for loading the workpiece into the holding table, and a holding table. A grinding apparatus including at least a grinding area for grinding a held workpiece and an unloading area for unloading the workpiece from a holding table, wherein the holding table positions the holding table in a loading area, a grinding area, and an unloading area. Provided is a grinding device provided with a table positioning means and a support base for supporting a holding table positioned in a grinding area by the holding table positioning means.

In this grinding apparatus, grinding means rotatably supporting a grinding wheel is disposed in a grinding area, and the grinding means faces a holding table positioned in the grinding area and supported by a support base. The holding table positioning means includes a table support for rotatably and vertically moving the holding table, a turntable provided with the table support, and a driving unit for driving the turntable. The drive unit is provided with lifting means for raising and lowering the turntable and positioning the turntable at the upper position and the lower position.When the turntable is positioned at the upper position, the turntable is Position the holding table that is indexed and rotated and supported by the table support in one of the loading area, grinding area, and unloading area, and turn it. When the cable is positioned at the lower position, the holding table is supported by the support base, and the holding table includes a workpiece holding portion and a frame surrounding the workpiece holding portion. The body is supported by the table support so as to rotate and move up and down. The support base rotates the holding table support that supports the holding table, a suction path that transmits suction force to the workpiece holding unit, and the holding table. The holding table comprises a workpiece holding portion, a frame surrounding the workpiece holding portion, and a suction hole for transmitting a suction force to the workpiece holding portion. , The frame is rotatably supported by the table support unit and can be moved up and down,
An additional requirement is that the support base includes a holding table supporting portion for supporting the holding table and a rotating portion for rotating the holding table.

In the grinding apparatus configured as described above, when the workpiece held by the holding table is positioned in the grinding area, the holding table is supported by the support base. The pressing force is not affected by the pressing force applied at this time, and this pressing force is received only by the support base. Therefore, rigidity is not required for the holding table positioning means. Further, since the turntable constituting the holding table positioning means does not bend, the grinding accuracy does not decrease.

Further, the workpiece is transported to the carry-in area, the grinding area, and the carry-out area while being held on the holding table, so that the workpiece is handled more carefully than when only the workpiece is transported. And the time required for transport is short. Further, since the holding table is also positioned in the carry-in area and the carry-out area, the holding table can be easily cleaned.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, FIG.
The following describes the grinding device 10 shown in FIG. First, the outline of the grinding device 10 will be described.
Are cassettes 11 and 12 containing semiconductor wafers W
Loading / unloading means 13 for loading / unloading semiconductor wafers W from cassette 11 or loading / unloading semiconductor wafers W into cassette 12, centering tables 14a and 14b for aligning workpieces, and transporting workpieces. The first transfer means 15 and the second transfer means 16 to be performed, four holding tables 17 having a chuck surface for sucking and holding the semiconductor wafer W thereon, and the four holding tables 17 are rotatably supported and themselves. Holding table positioning means 18 for rotating and positioning each holding table at a predetermined position, grinding means 19a and 19b for grinding a semiconductor wafer W held on each holding table, and holding table cleaning means for cleaning each holding table 20 and a workpiece cleaning means 21 for cleaning the workpiece after grinding.

A workpiece before grinding, for example, a semiconductor wafer, is stored in a plurality of stages in the cassette 11, and is picked up one by one by the loading / unloading means 13 and placed on the centering table 14a. After the alignment of the semiconductor wafer is performed here, the semiconductor wafer W is attracted to the first transfer means 15 and the first transfer means 15 pivots, so that the semiconductor wafer W is placed on the holding table 17 located in the vicinity. Is placed. The area where the holding table 17 is located at this time is called a carry-in area.

Next, the turntable 35 constituting the holding table positioning means 18 is rotated by a required angle (90 degrees in the case of four holding tables as in the present embodiment), and the holding table on which the semiconductor wafer is placed is placed. 17 is located immediately below the grinding means 19a. At this time, another holding table 17 is automatically positioned at a position where the holding table 17 was positioned before the rotation of the turntable 35. Then, the semiconductor wafer to be ground next is unloaded from the cassette 11 and placed on the centering table 14a. After the alignment, the semiconductor wafer is transferred to the holding table 17 by the first transfer means 15 and placed thereon. on the other hand,
The upper surface of the semiconductor wafer positioned immediately below the grinding means 19a is ground by the action of the grinding means 19a.
Here, for example, rough finishing is performed.

When the rough finishing of the semiconductor wafer held by the holding table 17 is completed, the turntable 35 is rotated by a required angle, and the rough finished semiconductor wafer is positioned immediately below the grinding means 19b.
The upper surface is ground by the action of 9b. Here, for example, final finishing is performed. Further, at this time, the semiconductor wafer before grinding is positioned immediately below the grinding means 19a, where rough finishing is performed by the action of the grinding means 19a. A region where the holding table 17 is positioned when the grinding is performed by the grinding means 19a and 19b is referred to as a grinding region.

The grinding means 19a and 19b can move up and down with respect to the upright wall portion 22. Here, since the grinding means 19a and the grinding means 19b have the same configuration except for the type of the grinding wheel, a description will be given with common reference numerals. The rails 23 are installed in the vertical direction,
As the sliding portion 25 moves up and down along, the grinding means 19a and 19b fixed to the sliding portion 25 move up and down.

In the grinding means 19a and 19b, a mounter 27 is attached to the tip of a spindle 26 rotatably supported.
, A grinding wheel 28 is mounted, and a grinding wheel 29 is fixed to a lower portion of the grinding wheel 28. As the grinding wheel 29, for example, a grinding wheel for rough finishing is used for the grinding means 19a, and a grinding wheel for final finishing is used for the grinding means 19b.

The semiconductor wafer ground by the final finishing is positioned near the second transfer means 16 by the rotation of the turntable 35. Then, after being transported by the second transporting means 16 to the workpiece cleaning means 21 and washed, the workpiece is further transported by the second transporting means 16 to the centering table 14b. At this time, the area where the holding table 17 is positioned is referred to as a carry-out area.

When the centering table 14b is positioned at a predetermined position, the semiconductor wafer ground by the carrying-in / out means 13 is picked up and stored in the cassette 12. Grinding is performed sequentially as described above, and finally, all the ground semiconductor wafers W are stored in the cassette 12.

The holding table cleaning means 20 includes a guide rail 30 provided above the turntable 35.
And a movable part 31 that is movable by a predetermined range guided by the guide rail 30, and a vertical moving part 32 that moves vertically in the vertical direction with respect to the movable part 31. Provided with a cleaning brush 33 capable of moving the movable part 31 when the holding table 17 is contaminated by grinding.
Is moved to the required position by moving the guide rail 30 in a required range, and furthermore, the cleaning brush 33 is rotated by lowering the vertical moving part 32 while rotating the cleaning brush 33.
Thereby, the holding table 17 is washed.

As shown in FIG. 2, the holding table positioning means 18 includes a table support 34 for rotatably and vertically moving the holding table 17, a turntable 35 on which the table support 34 is formed, and a turntable 35. And a driving unit 36 for driving the driving unit.
A motor 37 is connected to the turntable 35 and drives the turntable 35 to rotate. Motor 37
For example, a rotary encoder is provided, and the holding table 18 can be positioned at a predetermined position by index rotation of a predetermined angle (for example, 90 degrees). Further, the motor 37 is connected to the lifting / lowering means 38 so that the turntable 35 can be moved up and down.

A table support portion 34 formed on the turntable 35 has a work holding portion 39 for holding a work to be mounted thereon and a frame 40 surrounding the work holding portion 39.
Are freely supported rotatably and vertically movable.

Each holding table is supported from below by a support base 41 when positioned just below the grinding means 19a or 19b in the grinding area. That is, the grinding means 19a (19b) faces the holding table 17 which is positioned in the grinding area and supported by the support base 41.

The support base 41 includes a holding table supporting portion 42 for supporting each holding table, a suction passage 43 for transmitting a suction force to the workpiece holding portion 39 of the holding table 17,
A rotary unit 44 supported by the bed 45 and rotating the holding table 17 by rotating itself is generally configured.

The turntable 35 is moved by the lifting / lowering means 38.
Is positioned in the upper position, the turntable 35
The frame body 40 is supported by the table support portion 34 of the above, and the holding table 17 can be positioned in any of the carry-in area, the grinding area, and the carry-out area by indexing and rotating the turntable 35. The elevating means 38 is connected to the support base 4.
1, the frame 40 may be supported by the turntable 35 by lowering the support base 41. That is, it is sufficient that the support base 40 and the turntable 35 are configured to move up and down relatively.

When the holding table 17 is positioned in the grinding area by the indexing rotation of the turntable 35,
It will be located immediately below the grinding means 19a or the grinding means 19b. Then, when the turntable 35 is lowered by being driven by the elevating means 38 and positioned at the lower position, the holding table 17 is supported by the support base 41, as shown in FIG.

Here, the support base 41, the holding table 17
The internal structure of the holding table positioning means 18 will be described. An electromagnet 46 is embedded in the holding table support portion 42 of the support base 41, and a magnetic attachment member 47 is provided below the frame 40. When the turntable 35 is lowered by the lifting / lowering means 38, the electromagnet 46 and the magnetic member 47 are magnetically attached, and the holding table 17 is firmly fixed by the support base 41. Turntable 3 at this time
The position 5 is the lower position. And turntable 3
5 further lowers slightly, so that the holding table 17
Is rotatable while being freely supported by the table support portion 34. Note that a vacuum source may be provided instead of the electromagnet 46, and the holding table 17 may be fixed by an attractive force.

At the center of the support base 41, a suction passage 48 is formed in the vertical direction.
When the holding table 17 is fixed, the suction path 48 communicates with a suction hole 49 formed in the holding table 17, and further communicates with the workpiece holding section 39. The workpiece can be held in the workpiece holding unit 39 by a suction force supplied from a suction source (not shown) communicating with the suction path 48. The workpiece holding section 39 is preferably formed of, for example, porous ceramics.

Further, the rotating portion 44 of the support base 41 is provided with a motor 50, and when the rotating portion 44 is rotated by the motor 50, the holding table 17 fixed to the support base 41 and holding the workpiece also rotates. It has a configuration.

As described above, when the work held on the holding table 17 is ground in a state where the turntable 35 is positioned at the lower position and the holding table 17 is fixed to the support base 41, the grinding means 19a (19b) ) Applies a pressing force from above, but this pressing force is received only by the support base 41 without being applied to the holding table positioning means 18. Therefore, the grinding is performed with the holding table 17 being stably supported by the rigidity of the support base 41, so that the accuracy of the grinding is improved and the quality of the workpiece can be improved.

Further, the rigidity of the support table 41 does not require the turntable 35 to be rigid, so that the weight of the holding table positioning means 18 and the size of the apparatus are not increased, so that the cost is not increased. Further, if the support base 41 is provided below the holding table cleaning means 20, not only during grinding, but also when the holding table cleaning means 2 is used.
Since the holding table 17 is also supported in the same manner as described above when the holding table 17 is cleaned by 0, the cleaning can be sufficiently performed.

Further, the workpiece is transported to the carry-in area, the grinding area, and the carry-out area while being held on the holding table 17, and the handling of the workpiece is more careful than when only the workpiece is transported. And the time required for transportation is short, so that the throughput does not decrease.

As shown in FIG. 3, a waste liquid guide 51 for guiding the flow of grinding water used for grinding the workpiece projects from a position below the turntable 35 on the side surface of the frame body 40. As shown in FIG. 4, a rotary waste liquid receiver 52 is provided below the rotary waste liquid receiver 52.
The guide 2 guides the waste water to the fixed waste liquid receiver 53 provided further below the rotary waste liquid receiver 52. Then, the waste liquid collected in the fixed waste liquid receiver 53 is drained through the drain 54. Although not shown in FIG. 3, a main body waste liquid receiver 55 shown in FIGS. 4 and 5 is provided around the turntable 35, and the waste liquid collected there is also guided toward the fixed waste liquid receiver 53. Is done.

When the workpiece is ground in the grinding area, as shown in FIG. 5, the grinding water is supplied from the grinding wheel 28 to the workpiece 57 through the grinding water supply path 56 provided in the grinding means 19a (19b). Is supplied. Then, the used waste liquid passes through a small gap formed between the holding table 17 and the turntable 35 and a small gap formed between the turntable 35 and the main body waste liquid receiver 55,
The waste liquid flows into the fixed waste liquid receiver 53 via the rotary waste liquid receiver 52, and the waste liquid collected here is discharged from the drain 54.

The support base 41, the holding table 17, and the holding table positioning means 18 in FIG.
May be configured as shown in FIG. The configuration in FIG. 6 differs from the configuration in FIG. 3 in that the suction force in the workpiece holding unit 39 is supplied from the holding table positioning unit 60.

3 will be described with the same reference numerals. In the case of the configuration of FIG. 6, the suction path 62 passing through the rotary shaft 61 is Through a flexible hose 64 and a rotary joint 66 surrounding the frame 65 to a suction hole 67 formed in the frame 65, and from a suction source (not shown) communicating with the suction path 62. The workpiece is held in the workpiece holding section 68 by the supplied suction force. Accordingly, since the suction force is always supplied to the workpiece holding section 68, the workpiece does not shift from the holding table 17 even when the turntable 35 rotates. .

Also in this case, when the motor 69 and the turntable 63 are lowered to the lower position by the lifting / lowering means 38, the electromagnet 46 and the magnetically attaching member 47 are magnetically attached, and the holding table 70 is firmly fixed by the support base 41. Fixed to Then, when the workpiece held by the holding table 17 is ground in a state where the holding table 70 is fixed to the support base 41, even if a pressing force is applied from above by the grinding means 19, due to the rigidity of the support base. Since the workpiece does not bend, the precision of the grinding is improved. In addition, if the support base 41 is provided below the holding table cleaning means 20 in addition to the grinding, the workpiece does not bend even when the holding table 17 is cleaned, so that the cleaning is sufficiently performed. In this respect, the quality of the workpiece can also be improved.

[0039]

As described above, in the grinding apparatus according to the present invention, the holding table is supported by the support base when the workpiece held by the holding table is positioned in the grinding area. Even if a pressing force is applied from above by the grinding means during grinding, the pressing force is not applied to the holding table positioning means, but is received by the entire support base. Therefore, the turntable does not bend, and the rigidity of the support base allows the grinding to be performed while the holding table is stably supported, so that the accuracy of the grinding is improved and the quality of the workpiece is improved. Can be done.

Further, the rigidity of the turntable is not required due to the rigidity of the support table. Therefore, the weight of the holding table positioning means and the size of the apparatus are not increased, and the cost is not increased.

Further, the workpiece is transported to the carry-in area, the grinding area, and the carry-out area while being held on the holding table, and the handling of the workpiece is handled more carefully than when only the workpiece is transported. Since there is no need to perform this process and the time required for transport is short, there is no reduction in throughput.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an embodiment of a grinding device according to the present invention.

FIG. 2 is a perspective view showing a holding table, a holding table positioning means, and a support base which constitute the grinding apparatus.

FIG. 3 is a sectional view showing the holding table, the holding table positioning means, and a support base.

FIG. 4 is a perspective view showing a waste liquid receiving member for discharging waste liquid and a waste liquid guide in the grinding device according to the present invention.

FIG. 5 is an explanatory view showing a state in which a workpiece is ground while supplying grinding water in the grinding apparatus.

FIG. 6 is a sectional view showing a second example of the holding table, the holding table positioning means, and the support base.

FIG. 7 is a perspective view showing a conventional grinding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Grinding apparatus 11, 12 ... Cassette 13 ... Carry-in / out means 14a, 14b ... Centering table 15 ... First carrying means 16 ... Second carrying means 17 ... Holding table 18 ... Holding table positioning means 19a, 19b ... Grinding Means 20: Holding table cleaning means 21: Workpiece cleaning means 22: Wall part 23 ... Rail 24 ... Drive source 25 ... Slide part 26 ... Spindle 27 ... Mounter 28 ... Grinding wheel 29 ... Grinding wheel 30 ... Guide rail 31 ... Movable Part 32 ... Vertical moving part 33 ... Cleaning brush 34 ... Table support part 35 ... Turntable 36 ... Drive part 37 ... Motor 38 ... Elevating means 39 ... Workpiece holding part 40 ... Frame 41 ... Support base 42 ... Holding table Supporting part 43 ... Suction path 44 ... Rotating part 45 ... Bed 46 ... Electromagnet 47 ... Magnetic member 48 ... Suction path 4 ... Suction hole 50 ... Motor 51 ... Waste liquid guide 52 ... Rotary waste liquid receiver 53 ... Fixed waste liquid receiver 54 ... Drain 55 ... Main body waste liquid receiver 56 ... Grinding water supply path 57 ... Workpiece 60 ... Holding table positioning means 61 ... Rotating shaft 62 ... Suction path 63 ... Turn table 64 ... Flexible hose 65 ... Frame body 66 ... Rotary joint 67 ... Suction hole 68 ... Workpiece holding part 69 ... Motor 70 ... Holding table 80 ... Grinding device 81 ... Holding table 82 ... Grinding means 83 ... turntable 84 ... grinding wheel 85 ... grinding wheel

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3C034 AA08 BB01 BB71 CB11 DD08 3C043 BA03 BA09 BA16 CC04 CC11 DD05 EE04 3C058 AA04 AB04 AB06 BC02 CB01 CB05 DA17

Claims (6)

[Claims] A holding table for holding the workpiece, a loading area for loading the workpiece into the holding table, a grinding area for grinding the workpiece held on the holding table;
A grinding apparatus including at least an unloading area for unloading a workpiece from the holding table, a holding table positioning means for positioning the holding table in the loading area, the grinding area, and the unloading area; A grinding device, comprising: a support base that supports the holding table positioned in the grinding area by positioning means. 2. A grinding area in which a grinding wheel rotatably supported by a grinding area is provided, wherein the grinding means comprises:
The grinding device according to claim 1, wherein the grinding device is disposed at a position facing the holding table that is positioned in the grinding area and supported by the support base. 3. The holding table positioning means includes: a table support for rotatably and vertically moving the holding table; a turntable on which the table support is disposed;
The grinding device according to claim 1, further comprising at least a driving unit that drives the turntable. 4. The drive unit is provided with elevating means for elevating and lowering the turntable so as to be positioned at an upper position and a lower position. When the turntable is positioned at the upper position, the turntable is moved up and down. Position the holding table, which is indexed and rotated and supported by the table support, in one of the carry-in area, the grinding area, and the carry-out area, and when the turntable is positioned at the lower position, the holding table is placed on the support base. The grinding device according to claim 3, which is supported. 5. The holding table includes a workpiece holding portion and a frame surrounding the workpiece holding portion. The frame is rotatably and vertically movable supported by a table supporting portion. 5. The base according to claim 4, wherein the base includes a holding table supporting portion that supports the holding table, a suction path that transmits a suction force to the workpiece holding portion, and a rotating portion that rotates the holding table. Grinding equipment. 6. The holding table includes a workpiece holding portion, a frame surrounding the workpiece holding portion, and a suction hole for transmitting a suction force to the workpiece holding portion. 5. The body according to claim 4, wherein the body is rotatably and vertically supported by the table support, and the support base includes a holding table support for supporting the holding table, and a rotating unit for rotating the holding table. Grinding equipment.