JP6246533B2 - Grinding equipment - Google Patents

Description

  The present invention relates to a grinding apparatus that grinds a plate-like workpiece, and relates to a grinding apparatus that can grind a plate-like workpiece so that an annular convex portion is formed on the outer periphery by a grinding wheel of a grinding means.

  2. Description of the Related Art In recent years, in the semiconductor chip manufacturing process, it has been desired to reduce the thickness of a semiconductor wafer as a plate-like workpiece for the purpose of improving heat dissipation as well as reducing the size and weight of electronic devices. However, the thinned semiconductor wafer has a problem that the rigidity is lowered as compared with the semiconductor wafer before thinning, and warpage is generated and the conveyance risk is high.

  Therefore, in order to solve this problem, only the region corresponding to the device formation region in which the device is formed is ground at the center of the back surface of the semiconductor wafer to form a concave shape, and an annular shape for reinforcement in the outer peripheral region of the device region. The thing which formed the convex part of this is utilized (refer patent document 1).

  In a grinding apparatus for forming an annular convex portion on a semiconductor wafer, the semiconductor wafer is held by a holding table, and grinding is performed by bringing the grinding wheel into contact with the back surface of the semiconductor wafer while rotating a grinding wheel on which the grinding wheel is arranged. . In this grinding, an annular convex portion is formed by not grinding only a predetermined width region along the outer edge of the semiconductor wafer.

JP 2010-171100 A

  In the grinding apparatus, since the grinding wheel wears with time, when the grinding wheel is replaced, there is a slight difference in the outer diameter of the grinding wheel before and after the replacement. For this reason, there exists a problem that the width | variety of the convex part formed by grinding will change before and after exchanging a grinding wheel.

  FIG. 7 is an explanatory cross-sectional view showing a state after grinding a semiconductor wafer according to the prior art. The outer peripheral portion of the semiconductor wafer W shown in FIG. 7 is subjected to a first grinding process using a grinding wheel as rough grinding, and then a second grinding process using a grinding wheel having a finer grain size than the first grinding process as finish grinding. It is formed by performing.

  In FIG. 7A, by performing grinding in the first grinding process, the center of the back surface is ground in a concave shape except for the region along the outer edge of the semiconductor wafer W to form the first ground surface Wa. Thereafter, the second grinding surface Wb is ground by grinding the bottom surface of the first grinding surface Wa except for a predetermined width region along the outer edge of the first grinding surface Wa by performing grinding in the second grinding step. Form. Thus, an annular convex portion W1 is formed along the outer edge of the semiconductor wafer W, and a step surface W1a is formed inside the convex portion W1.

  Here, in the second grinding step, when the outer peripheral position of the grinding wheel is shifted inward in the radial direction of the semiconductor wafer W (right side in FIG. 7A), the left and right width in FIG. 7A of the step surface W1a in the convex portion W1 is also in the radial direction. Get bigger on the inside. Then, the inner peripheral surface W1b of the convex portion W1 formed by the second grinding surface Wb is also formed on the radially inner side of the semiconductor wafer W and overlaps with the device D positioned on the outer surface of the semiconductor wafer W. As a result, when the protrusion W1 is removed from the semiconductor wafer W in a later step, a crack C occurs along the inner peripheral surface W1b of the protrusion W1, and the outer device D is damaged by the crack C. There's a problem.

  FIG. 7B shows a state where the grinding wheel is shifted to the outside in the radial direction of the semiconductor wafer in the second grinding step after the first grinding step is performed as in FIG. 7A. Normally, the side surface of the first ground surface Wa ground in the first grinding step is not ground in the second grinding step, but in FIG. 7B, the side surface of the first ground surface (not shown) is second ground. Since grinding is performed in the process, wear of the grinding wheel 100 used in the second grinding process increases. In particular, since the side surface of the grinding wheel 100 is worn, the intersection of the side surface and the bottom surface of the grinding wheel 100 is not a right angle but is rounded, and it may not be possible to grind to the corresponding position on the outside of the device D (left side in FIG. 7B). To do. As a result, when the convex portion W1 is removed from the semiconductor wafer W, there is a problem that the device D is damaged because a crack is easily generated inside the convex portion W1.

  The present invention has been made in view of such a point, and even if the grinding wheel of the grinding means is replaced, the width of the annular convex portion formed on the outer periphery of the plate-like workpiece is ground to a prescribed value that is prescribed in advance. An object of the present invention is to provide a grinding apparatus capable of performing the above.

The grinding apparatus according to the present invention includes a holding table for holding a plate-like workpiece, and a plate-like workpiece held on the holding table for grinding by bringing an abrasive wheel disposed in an annular shape into contact with the plate-like workpiece and grinding the plate-like workpiece on the outer periphery. Measures the width of the convex part Measuring means for measuring the width of the convex portion of the plate workpiece ground by the measuring means, and a prescribed value for the width of the convex portion defined in advance. , And a control unit that moves the grinding means by using the advancing / retreating means, and the outer surface of the grinding wheel arranged in an annular shape is worn , so that the convex part is The measured value measured by the measuring means is When it becomes greater than the value, characterized in that finish the width of the convex portion of the moving means control unit is controlled to so as to move only radially outside the grinding means determined in the calculating portion in the width of the specified value.

  According to this configuration, the drive of the advance / retreat means is controlled based on the result of measuring the width of the convex portion, and the grinding means is advanced / retracted in the radial direction of the table. Therefore, even if the grinding wheel having the grinding wheel is replaced, the grinding is performed. By correcting the position of the wheel, the width of the convex portion can be finished to a specified value. As a result, when a device or the like is formed on a plate-like workpiece, the width of the convex portion can be prevented from being overlapped with the device, and the device can be prevented from being damaged when the convex portion is removed. it can. Moreover, the width of the convex portion becomes narrow and the rigidity is reduced, and the convex portion can be prevented from cracking. In addition, the grinding wheel is rounded as described above, and the base side of the convex portion is also rounded. Thus, the device can be prevented from being damaged when the convex portion is removed.

  According to the present invention, even if the grinding wheel of the grinding means is exchanged, the width of the annular convex portion formed on the outer periphery of the plate-like workpiece can be ground to a prescribed value that is defined in advance.

It is an external appearance perspective view of the semiconductor wafer after grinding concerning this embodiment. It is a perspective view which shows an example of the grinding device which concerns on this Embodiment. It is a schematic diagram which shows the principal part of the said grinding apparatus. It is explanatory drawing which shows an example of the measurement result in the measurement means which concerns on this Embodiment. It is explanatory drawing which shows another example of the measurement result in the measurement means which concerns on this Embodiment. It is sectional drawing for description which shows the state after grinding the semiconductor wafer which concerns on this Embodiment. It is sectional drawing for description which shows the state after grinding the semiconductor wafer by a prior art.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The grinding apparatus according to the embodiment of the present invention forms convex portions on the outer periphery of the back surface of the semiconductor wafer. Before describing a grinding apparatus according to an embodiment of the present invention, first, a semiconductor wafer to be ground will be briefly described. FIG. 1 is an external perspective view of a semiconductor wafer after grinding according to an embodiment of the present invention. FIG. 1A shows the front surface of the semiconductor wafer, and FIG. 1B shows the back surface of the semiconductor wafer.

  As shown in FIG. 1A, the unprocessed semiconductor wafer W is formed in a substantially disc shape, and is partitioned into a plurality of regions by unscheduled division lines (not shown) arranged in a lattice pattern on the surface. A device D such as an IC or LSI is formed in the center of the semiconductor wafer W in each region partitioned by the division lines. Further, the surface of the semiconductor wafer W is divided into a device forming region 62 in which the device D located at the central portion is formed and an outer peripheral region 63 positioned around the device forming region 62.

  As shown in FIG. 1B, a region corresponding to the device formation region 62 is removed from the back surface of the semiconductor wafer W, and a region corresponding to the outer peripheral region 63 protrudes in a ring shape to form a convex portion W1 for reinforcement. And the recessed part W2 is formed in the back surface of the semiconductor wafer W, and only the device formation area 62 is thinned. The semiconductor wafer W in which the recess W2 is formed is accommodated in the cassette 2 (see FIG. 2) and is carried into the grinding apparatus 1.

  In the present embodiment, a semiconductor wafer W such as a silicon wafer will be described as an example of the plate-like workpiece. However, the present invention is not limited to this configuration, and a semiconductor product package, ceramic, glass, sapphire, The workpiece may be a silicon-based substrate, various electrical components, or various processed materials that require micron-order accuracy.

  Next, a grinding apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 2 is an external perspective view of the grinding apparatus according to the present embodiment. FIG. 3 is a schematic view showing a main part of the grinding apparatus according to the present embodiment.

  As shown in FIG. 2, the grinding apparatus 1 carries in a semiconductor wafer W before processing, a loading / unloading unit 4 for unloading the processed semiconductor wafer W, and a semiconductor wafer W loaded from the loading / unloading unit 4. It is comprised from the convex part formation unit 5 which forms the convex part W1 by grinding. The carry-in / carry-out unit 4 has a rectangular parallelepiped base 11, and the base 11 is provided with a pair of cassette placement portions 12 and 13 on which the cassettes 2 and 3 are placed so as to protrude forward from the front surface 11a. It has been.

  The cassette mounting unit 12 functions as a carry-in port, and the cassette 2 in which the unprocessed semiconductor wafer W is stored is mounted. The cassette mounting portion 13 functions as a carry-out port, and the cassette 3 in which the processed semiconductor wafer W is accommodated is mounted. On the upper surface of the base 11, a carry-in / carry-out arm 14 is provided so as to face the cassette mounting parts 12, 13. 15. Spinner cleaning units 16 are provided at the other corners, respectively. Further, on the upper surface of the base 11, a wafer supply unit 17 and a wafer recovery unit 18 are provided between the temporary placement unit 15 and the spinner cleaning unit 16.

  The carry-in / carry-out arm 14 carries the semiconductor wafer W from the cassette 2 placed on the cassette placement unit 12 to the temporary placement unit 15, and from the spinner cleaning unit 16 to the cassette 3 placed on the cassette placement unit 13. The semiconductor wafer W is unloaded. The temporary placement unit 15 includes a temporary placement table 21 and an imaging unit 22, images the outer peripheral portion of the semiconductor wafer W placed on the temporary placement table 21, and performs image processing to center the semiconductor wafer W. A positional deviation amount between the position and the center position of the temporary placement table 21 is calculated.

  The wafer supply unit 17 is placed on the holding table 34 of the convex portion forming unit 5 while correcting the positional shift amount of the unprocessed semiconductor wafer W placed on the temporary placement table 21. The wafer recovery unit 18 places the processed semiconductor wafer W placed on the holding table 34 on the spinner cleaning table 23 of the spinner cleaning unit 16. The spinner cleaning unit 16 rotates the semiconductor wafer W placed on the spinner cleaning table 23 in the base 11 and sprays cleaning water to clean it.

  The convex forming unit 5 includes a rough grinding unit (grinding means) 32, a finish grinding unit (grinding means) 33, and a holding table 34 for holding the semiconductor wafer W, and is configured to grind the semiconductor wafer W. Yes. Further, the convex forming unit 5 has a rectangular parallelepiped base 31, and the carry-in / out unit 4 is connected to the front surface of the base 31. A turntable 35 on which three holding tables 34 are arranged is provided on the upper surface of the base 31, and a column portion 36 is erected on the rear side of the turntable 35.

  The holding table 34 has a disk shape, and a suction holding surface 34a is formed in a circular shape by a porous ceramic material at the center of the upper surface. The suction holding surface 34 a is connected to a suction source (not shown) disposed in the base 31 and holds the semiconductor wafer W by suction. The holding table 34 is configured to be rotatable about an axis perpendicular to the suction holding surface 34a by a rotation driving mechanism (not shown).

  The turntable 35 is formed in a large-diameter disk shape, and three holding tables 34 are arranged on the upper surface at intervals of 120 degrees in the circumferential direction. The turntable 35 is connected to a rotation drive mechanism (not shown), and is intermittently rotated at intervals of 120 degrees in the direction D1 by the rotation drive mechanism. Thereby, the three holding tables 34 are a transfer position for transferring the semiconductor wafer W between the wafer supply unit 17 and the wafer recovery unit 18, a rough grinding position for facing the semiconductor wafer W to the rough grinding unit 32, and finish grinding. It moves between finish grinding positions where the semiconductor wafer W faces the unit 33.

  On the upper surface of the base 31, contact sensors 38 and 39 are provided in the vicinity of the rough grinding position and the finish grinding position of the turntable 35. The contact sensors 38 and 39 have two contacts, one contact is in contact with the recess W2 of the semiconductor wafer W, and the other contact is in contact with the suction holding surface 34a. The grinding depth is controlled from the difference in height between the two contacts.

  The column portion 36 is formed in a base shape having a pair of slopes as viewed from above, and the pair of slopes is provided with advance / retreat means 41 and 42 for moving the rough grinding unit 32 and the finish grinding unit 33 above the holding table 34. ing. The pair of inclined surfaces of the support column 36 have an angle that allows the rough grinding unit 32 and the finish grinding unit 33 to move in the direction in which the holding table 34 advances and retreats in the radial direction. The advancing / retreating means 41 has a pair of guide rails (not shown) arranged on the slope of the support column 36 and parallel to each other in the left-right direction, and a motor-driven R-axis table 43 slidably installed on the pair of guide rails. ing.

  Further, the advancing / retreating means 41 is provided with a grinding feed means 44 for grinding and feeding in the grinding feed direction for causing the rough grinding unit 32 to approach and separate from the holding table 34. The grinding feed means 44 includes a pair of guide rails 45 disposed in front of the R-axis table 43 and parallel to each other in the vertical direction, and a motor-driven Z-axis table 46 slidably disposed on each of the pair of guide rails 45. have. The rough grinding unit 32 is supported on the Z-axis table 46 via a support portion 47 attached to the front surface. The advance / retreat means 42 also has the same configuration as the advance / retreat means 41, is provided with a grinding feed means 44, and supports the finish grinding unit 33.

  A nut portion (not shown) is formed on the back side of each R-axis table 43 and each Z-axis table 46, and a ball screw 48 is screwed to these nut portions (the ball screw for the R-axis table is not shown). ). A drive motor 49 is connected to the upper end of each of the ball screw for the R-axis table 43 and the ball screw 48 for the Z-axis table 46, and the ball screw is rotationally driven by the drive motor 49 (drive for the R-axis table). (The motor is not shown). With such a configuration, the R-axis table 43 moves in the R1 direction and the R2 direction, respectively, and the Z-axis table 46 moves in the vertical direction.

  The rough grinding unit 32 includes a unit housing 51, a spindle (not shown) that is rotationally driven by a motor 52 inside the unit housing 51, and a grinding wheel 53 that is detachably attached to the lower end of the spindle. A plurality of grinding wheels 54 are annularly arranged on the grinding wheel 53. The rough grinding unit 32 causes the grinding wheel 54 to rotate and come into contact with the semiconductor wafer W held on the rotated holding table 34, and sprays a grinding liquid onto the semiconductor wafer W from a nozzle (not shown). In the rough grinding unit 32, the position of the grinding wheel 54 in the radial direction (R1 direction) of the semiconductor wafer W is adjusted by the advancing / retreating means 41, the grinding feed means 44 is ground and fed in the vertical direction, and the recess W2 is formed in the semiconductor wafer W. And the convex part W1 is formed.

  The grinding wheel 54 is composed of a diamond wheel in which diamond abrasive grains are hardened with a binder such as a metal bond or a resin bond. The finish grinding unit 33 has the same configuration as that of the rough grinding unit 32 and performs the same operation. However, a fine grindstone 54 is used as the grinding wheel 54.

  Measuring means 56 and 57 are provided above the holding table 34 at the rough grinding position and the finish grinding position. As the measuring means 56 and 57, an imaging camera having an imaging element such as a CCD or CMOS inside can be exemplified. The measuring means 56 and 57 are provided so as to be able to image the convex portion W1 of the semiconductor wafer W held by the holding table 34. 4 and 5 are explanatory diagrams illustrating an example of an imaging result in the measurement unit. In the present embodiment, since two grinding steps (first grinding step and second grinding step) are performed as described later, both grinding steps are performed in FIGS. 4 and 5 and the following description. About the value used by description including, the value of a 2nd grinding process is described in parenthesis after the value of a 1st grinding process. The measuring means 56 and 57 can measure the width of the convex portion W1 in the radial direction of the semiconductor wafer W from the imaging results shown in FIGS. 4 and 5, and can output the measured value H1 (H3) to the control means 80 described later. It is configured.

  Returning to FIG. 2, inside the base 31, a control means 80 is provided for overall control of each part of the grinding apparatus 1. The control unit 80 includes a processor that executes various processes, and a storage medium such as a ROM (Read Only Memory) and a RAM (Random Access Memory). For example, the control unit 80 controls the driving direction and driving amount of the advancing / retreating units 41 and 42 according to the measured value H1 of the width of the convex portion W1 measured by the measuring units 56 and 57. In the calculation unit 81 of the control unit 80, the measured value H1 (H3) of the width of the convex portion W1 by the measuring units 56 and 57 is compared with the predetermined value H2 (H4) of the width of the convex portion W1 defined in advance. The difference d1 (d2) is obtained (see FIGS. 4 and 5). Further, the control unit 82 of the control unit 80 drives the advance / retreat units 41 and 42 according to the difference obtained by the calculation unit 81 to advance and retract the rough grinding unit 32 and the finish grinding unit 33.

  Next, a grinding method using the grinding apparatus 1 of the present embodiment will be described with reference to FIG. FIG. 6 is an explanatory cross-sectional view showing a state after grinding the semiconductor wafer according to the present embodiment. In addition, as shown in FIG. 6, when grinding with the grinding apparatus 1, the protective tape 70 in which the adhesive layer 70b was laminated | stacked on the tape base 70a was previously affixed on the surface (lower surface) of the semiconductor wafer W. .

  First, the semiconductor wafer W for test is ground as the first semiconductor wafer W. In this grinding, after the carrying-in process of carrying the semiconductor wafer W into the rough grinding position, the first grinding process for forming the first grinding surface Wa by the rough grinding, the position of the grinding wheel 54 of the rough grinding unit 32 is determined. A first adjustment step for adjustment is performed. Then, the 2nd grinding process which forms the 2nd grinding surface Wb by finish grinding, and the 2nd adjustment process which adjusts the position of grinding wheel 54 of finish grinding unit 33 are performed.

  In the carry-in process, the surface of the semiconductor wafer W is placed on the suction holding surface 34a at the transfer position by the wafer supply unit 17 on the holding table 34. Then, the holding table 34 is moved to the rough grinding position by the rotation of the turntable 35 with the semiconductor wafer W held on the suction holding surface 34a with the back surface facing upward.

  When the holding table 34 moves to the rough grinding position, the first grinding process is performed. In this step, first, the R-axis table 43 of the advance / retreat means 41 is moved to advance and retract the rough grinding unit 32 in the radial direction of the holding table 34, so that the width a of the convex portion W1 becomes a predetermined specified value H2. The grinding wheel 54 is positioned. Before and after this, the upper surface position and thickness of the semiconductor wafer W are measured by the contact sensor 38, and the grinding feed amount is determined from these measurement results and the finished thickness of the recess W2 of the semiconductor wafer W defined in advance. Is required. Then, while continuously rotating the holding table 34 and the grinding wheel 54, the grinding wheel 54 is ground and fed downward by the determined grinding feed amount. Thereby, except for the region along the outer edge of the semiconductor wafer W, the center of the back surface is ground in a concave shape to form the first ground surface Wa. The width a of the convex portion W1 formed by the first grinding surface Wa is a distance from the outer edge of the semiconductor wafer W to the first grinding surface Wa extending in the vertical direction.

  After completing the formation of the first grinding surface Wa, the first adjustment step is performed. In this step, the convex portion W1 is imaged by the measuring means 56, and the width a of the convex portion W1 is measured from the imaging result. The measured value H1 of the width a of the convex portion W1 is output to the control means 80, and the arithmetic unit 81 compares the measured value H1 with a predetermined value H2 of the width of the convex portion W1 that is defined in advance. 4 and 5) are obtained. Then, the rough grinding unit 32 is moved forward and backward in the R1 direction by controlling the moving amount and moving direction of the advancing / retreating means 41 according to the difference d1 obtained by the calculating unit 81. Thereby, the position of the grinding wheel 54 in the R1 direction in the rough grinding unit 32 is corrected, and the width a of the convex portion W1 can be finished to the specified value H2 in the first grinding process (rough grinding) from the next time.

  After the first adjustment step, the holding table 34 is moved to the finish grinding position by the rotation of the turntable 35, and then the second grinding step is performed.

  The second grinding step is the same as the first grinding step. First, the R-axis table 43 of the advance / retreat means 42 is moved to advance and retract the finish grinding unit 33 in the radial direction of the holding table 34, and the width of the convex portion W1. The grinding wheel 54 is positioned so that b is a predetermined value H4 defined in advance. Before and after this, the contact-type sensor 39 measures the bottom surface position of the recess W2 and the thickness of the bottom side of the recess W2, and the grinding feed amount is obtained based on the measurement results and the like. Then, while the holding table 34 and the grinding wheel 54 are continuously rotated, the grinding wheel 54 is ground and fed by the grinding feed amount in the required downward direction. As a result, the center of the bottom surface of the first grinding surface Wa is ground into a concave shape except for the predetermined width region from the inner circumferential surface of the convex portion W1 formed in the first grinding step, thereby forming the second grinding surface Wb. Is done. At this time, a step surface W1a is formed inside the convex portion W1. The width b of the convex portion W1 formed by the second grinding surface Wb is a distance from the outer edge of the semiconductor wafer W to the second grinding surface Wb oriented in the vertical direction.

  After the formation of the second grinding surface Wb is completed, a second adjustment process is performed. In this step, the convex portion W1 is imaged by the measuring means 57, and the width b of the convex portion W1 is measured from the imaging result. The measured value H3 of the width b of the convex portion W1 is output to the control means 80, and the calculation unit 81 compares the measured value H3 with a predetermined value H4 of the width of the convex portion W1 to obtain a difference d2. Desired. And according to the difference d2 calculated | required by the calculating part 81, the movement amount and moving direction of the advancing / retreating means 42 are controlled by the control part 82, and the finish grinding unit 33 is moved forwards or backwards in R2 direction. Thereby, the position of the grinding wheel 54 in the R2 direction in the finish grinding unit 33 is corrected, and the width b of the convex portion W1 can be finished to the specified value H4 in the second grinding process (finish grinding) from the next time on.

  In each adjustment step described above, as shown in FIG. 4, when the measured value H1 (H3) of the measuring means 56, 57 is larger than the specified value H2 (H4), the advance / retreat means 41, 42 causes the semiconductor wafer W to move. The grinding wheel 54 is moved and positioned radially outward. Thereby, the position of the grinding wheel 54 can be corrected so that the widths a and b of the convex portion W1 are reduced. On the other hand, as shown in FIG. 5, when the measured value H1 (H3) of the measuring means 56, 57 is smaller than the specified value H2 (H4), the grinding wheel 54 is moved and positioned radially inward of the semiconductor wafer W. . Thereby, the position of the grinding stone 54 can be corrected so that the widths a and b of the convex portion W1 are increased.

  As described above, after grinding the test semiconductor wafer W, the product semiconductor wafer W is ground. In this grinding, the first adjustment step and the second adjustment step are omitted as compared with the grinding of the test semiconductor wafer W. Then, after the semiconductor wafer W for product is ground a plurality of times, when the position of the grinding wheel 54 needs to be adjusted by exchanging the grinding wheel 53 or the like, the first test is again performed on the semiconductor wafer W for testing. Grinding including the adjustment step and the second adjustment step is performed.

  As described above, according to the present embodiment, even if the outer diameter of the grinding wheel 54 changes before and after the replacement of the grinding wheel 53, the widths a and b of the projections W1 are defined in the semiconductor wafer W for products. It can be easily finished to the value H2 (H4). Thereby, it can avoid that the internal peripheral surface W1b of the convex part W1 is formed in the right side from the position shown in FIG. 6, and it overlaps with the device D, and when removing the convex part W1 from the semiconductor wafer W, it is in the internal peripheral surface W1b. It is possible to prevent the device D from being damaged by the crack C generated along the same. In addition, the inner peripheral surface of the convex portion W1 ground in the first grinding step can be prevented from being ground in the second grinding step, and the width b of the convex portion W1 is reduced and is not easily broken. be able to. Further, the inner peripheral surface of the convex portion W1 ground in the first grinding process is ground in the second grinding process to prevent the corners of the grinding wheel 54 in the finish grinding unit 33 from being rounded. be able to. Thereby, it is possible to avoid the formation of the inner peripheral surface of the convex portion W1 as shown in FIG. 7B, and it is possible to prevent the formation position of the crack C from overlapping the device D in the removal of the convex portion W1.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, in the grinding of the test semiconductor wafer W, the first adjustment process is performed after the first grinding process and the second adjustment process is performed after the second grinding process. However, the present invention is not limited to this. For example, during the formation of the respective grinding surfaces Wa and Wb, the widths a and b of the projections W1 are measured by the measuring means 56 and 57, and the advance / retreat means 41 and 42 are driven based on the measurement results, and the R1 and R2 directions Alternatively, the position of the grinding wheel 54 may be adjusted.

  Alternatively, the spinner cleaning unit 16 may be provided with a measurement unit 110 (see FIG. 2) having the same configuration as the measurement units 56 and 57. In this configuration, after the grinding is performed by omitting each adjustment step described above, the widths a and b of the convex portions W1 are measured by the measuring unit 110 on the semiconductor wafer W that has been transferred to the spinner cleaning unit 16 and cleaned. can do.

  In the above-described embodiment, the configuration includes the two grinding units of the rough grinding unit 32 and the finish grinding unit 33. However, the number of grinding units installed according to the number of grinding steps for one semiconductor wafer W is described. May be increased or decreased.

  As described above, the present invention has an effect that the width of the convex portion formed on the outer periphery of a plate-like workpiece such as a semiconductor wafer can be easily finished to a specified value.

1 Grinding equipment 32 Coarse grinding unit (grinding means)
33 Finish grinding unit (grinding means)
34 holding table 41, 42 advance / retreat means 44 grinding feed means 54 grinding wheel 56, 57 measuring means 81 arithmetic unit 82 control unit W semiconductor wafer (plate workpiece)
W1 Convex

Claims (1)

A holding table for holding a plate-shaped workpiece, and a grinding means for forming a ring-shaped convex portion on the outer periphery of the plate-shaped workpiece by grinding a plate-shaped workpiece held on the holding table by bringing a grinding wheel arranged in an annular shape into contact therewith And a forward / backward means for moving the grinding means forward and backward in the radial direction of the holding table, a grinding feed means for feeding the grinding means in a grinding feed direction for approaching and separating from the holding table, and a width of the convex portion A grinding device comprising at least measuring means,
A calculation unit that compares the measured value of the width of the convex portion of the ground plate workpiece measured by the measuring means with a predetermined value of the width of the convex portion defined in advance, and obtains a difference;
And a control unit that moves the grinding means using the advance / retreat means,
The outer surface of the grinding wheel arranged in an annular shape is worn, so that when the measured value measured by the measuring means is larger than the specified value , the radial direction is the same as the difference obtained by the calculating unit. A grinding apparatus in which the control unit controls the advance / retreat means to move the grinding means to the outside to finish the width of the convex portion to the width of the specified value.

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