JPH10217118A - Dressing method and device for grinding wheel on double side processing device for wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently dress a grinding wheel for both side grinding and make its bus bars in parallel with each other in high precision by making a pair of grinding wheels for grinding which rotate approach each other while making them contact with a grinding wheel for dressing between them and reciprocating the grinding wheel for dressing in the rotation axis direction of both of the grinding wheels for grinding. SOLUTION: Grinding wheels 24 for grinding are fixed in the circumference of a grinding wheel rotation axis 22. Dimensions of a clearance between the grinding wheels 24 for grinding are optionally adjusted by sliding and driving both of movable carriages 18 in opposite directions to each other by actuation of a grinding wheel delivery motor 28. Additionally, the grinding wheels 24 for grinding are driven to rotate in a specified direction around the grinding wheel rotation axis 22 as their center by actuation of a grinding wheel driving motor. Furthermore, a grinding wheel holding bar 56 is extensively provided downward from a ramp 54, and a grinding wheel 58 for dressing is fixed on its lower end. Its end surface is formed in a recessed curved shape to coincide with an outer peripheral surface of each of the grinding wheels 24 for grinding. Thereafter, a position of the whole of a dressing device 50 is set so that both end surfaces of the grinding wheel 58 for dressing simultaneously make contact with the outer peripheral surfaces of both of the grinding wheels 24 for grinding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for dressing a grindstone for processing both surfaces of a wafer made of a semiconductor or the like.

[0002]

2. Description of the Related Art Generally, the surface of a wafer made of a semiconductor such as silicon needs to be finished to a smooth surface having high flatness. Conventionally, as a means for performing such finishing processing, first, the wafer surface is lapped to obtain high flatness, and the crushed layer generated on the wafer surface due to the lapping and the surface layer contaminated with abrasive grains are chemically etched. A method of removing the surface and then smoothing the surface by mirror polishing is generally used.

[0003]

Since the lapping process is carried out in a complete batch system, the time required for wafer setting and wafer resetting is long, and the processing margin tends to vary from batch to batch. . Furthermore, the use of a wrapping agent has the disadvantage that workability and work environment deteriorate.

As a means for solving such a drawback, for example, a pair of columnar grinding wheels are arranged with a gap smaller than the thickness of the above-mentioned wafer in a state where their rotation axes are parallel to each other. An apparatus is conceivable in which a wafer is passed through a gap between both grinding wheels while simultaneously rotating the wafer, and both surfaces of the wafer are simultaneously brought into contact with the outer peripheral surfaces of both grinding wheels. According to such an apparatus, both sides of the wafer can be ground at the same time, and the production efficiency is dramatically improved.

However, in this apparatus, two grinding wheels are used. Therefore, a general dressing method conventionally known for dressing these grinding wheels, that is, a method of driving the grinding wheel while driving the rotary dresser, is used. If the method of contacting the outer peripheral surface is used, it takes a long time to finish dressing both grinding wheels, and the processing efficiency is reduced accordingly. In addition, in order to process both surfaces of the wafer with high accuracy by the above-described apparatus, it is necessary to accurately make the bus bars of both grinding wheels parallel to each other. However, a high degree of parallelism is realized by dressing using a conventional rotary dresser. It is very difficult.

In view of such circumstances, the present invention makes it possible to efficiently dress a grinding wheel for simultaneously processing both surfaces of a wafer and to make the bus bars of both grinding wheels parallel with high precision. It is an object to provide a method and an apparatus.

[0007]

According to the present invention, as a means for solving the above-mentioned problems, a pair of grinding wheels having a cylindrical outer peripheral surface are arranged so that their rotation axes are parallel to each other.
A method of dressing a grindstone in a double-sided wafer processing apparatus in which both surfaces of the wafer are simultaneously brought into contact with the outer peripheral surfaces of the two grindstones through the wafer between the two grindstones while rotating these grinding wheels. While rotating both grinding wheels, and holding the dressing wheel between both grinding wheels to bring both sides of the dressing wheel into contact with the outer peripheral surfaces of both grinding wheels, bring both grinding wheels closer together ,
The dressing grindstone is reciprocated along a direction parallel to the rotation axis of both grinding grindstones.

According to this method, both grinding wheels can be simultaneously dressed by simultaneously contacting both side surfaces of the dressing wheel with both grinding wheels. Moreover, by reciprocating the dressing grindstone in the axial direction in this state, it is possible to make the bus lines of the respective grinding grindstones along that direction, and as a result, the busbars can be made parallel. Therefore, in this state, both surfaces of the wafer can be made parallel by simultaneously grinding both surfaces of the wafer by passing the wafer between the two grinding wheels.

As the dressing grindstone, one having alumina abrasive grains or silicon carbide abrasive grains is preferable.
When such a dressing grindstone is used, the abrasive grains released from the grindstone tend to act uniformly on the grinding grindstone in the axial direction when the grindstone is moved in the axial direction. Is further improved.

In the above method, the dressing whetstone is reciprocated between a fixed first end position and a second end position, and a dress area formed by the dressing whetstone at the first end position and a second position. It is more preferable that both end positions are separated to such an extent that the dress area formed by the dressing grindstone at the end position 2 does not overlap. In this way, by preventing the dress area at the first end position from overlapping with the dress area at the second end position,
This overlapping portion can be prevented from being concentrated and shaved, and a more uniform dress can be realized in the axial direction.

In the above-mentioned dressing grindstone, free abrasive grains on the surface of the dressing grindstone are easily removed by a coolant or the like in a state where the dressing grindstone deviates in the axial direction from the grinding grindstone. When the grinding wheel is in constant contact with the grinding wheel, the loose abrasive particles are difficult to remove, so in order to achieve uniform surface properties of the dressing wheel in the axial direction and achieve high-precision grinding, the dressing wheel must be What is necessary is just to prevent the part which always contacts the said grinding wheel from occurring.
For this purpose, the two end positions may be separated to such an extent that the portion where the dressing grindstone contacts the grinding wheel at the first end position does not contact the grinding wheel at the second end position.

Further, the present invention is a dressing apparatus for a grinding wheel in the apparatus for double-sided processing of a wafer, wherein the grinding wheel transferring means for relatively moving the grinding wheels in a direction of coming and coming from each other,
A dressing grindstone that makes its dress by sliding contact with these grinding whetstones, and at a position where the dressing whetstone is sandwiched between the two grinding whetstones, the dressing whetstone is placed in a direction parallel to the rotation axes of the two grinding whetstones. Dress operation means for reciprocating along.

Also in this apparatus, the dress operating means is configured to reciprocate the dressing grindstone between a specific first end position and a second end position, and the dressing grindstone is moved to the first end position. A dress area formed by a certain dressing whetstone does not overlap with a dress area formed by a dressing whetstone located at a second end position, and a portion where the dressing whetstone contacts the grinding whetstone at the first end position is a second end position. It is more preferable to set the first end position and the second end position to such an extent that they do not contact the grinding wheel.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described with reference to FIGS.

The wafer processing apparatus shown in FIGS. 2 to 4 has a bed 10. A grindstone table 12 is disposed on both left and right wings of the bed 10, and a wafer holding table 14 is disposed in the center of the back of both grindstone tables 12.

Each grindstone table 12 includes a fixed table 16 and a movable table 1.
8 is provided. The fixed base 16 extends in the left-right direction (the X-axis direction in FIGS. 2 and 4; hereinafter, simply referred to as “X-axis direction”) of the entire processing apparatus, and is fixed on the bed 10. The movable table 18 is supported on the fixed table 16 so as to be slidable in the X-axis direction, and is slid in the X-axis direction by a grinding wheel feed motor 28 and a feed screw mechanism (not shown).

A grindstone holding section 20 is formed at the front end (end from the center of the processing apparatus) of each moving table 18. A grinding wheel rotating shaft 22 extending vertically is rotatably held by the grinding wheel holding unit 20, and a grinding wheel 24 for grinding is fixed around the grinding wheel rotating shaft 22. When the two carriages 18 are slid in the opposite directions by the operation of the grinding wheel feed motor 28, the grinding wheels 24 come into contact with and separate from each other, so that the gap between the grinding wheels 24 can be arbitrarily adjusted. Has become. Each of the grinding wheel rotating shafts 22 has a grinding wheel drive motor 2.
The grinding wheel 24 is operated by the operation of the grinding wheel drive motor 26 so that the grinding wheel 24 rotates in a predetermined direction about the grinding wheel rotation shaft 22 (FIG. 1).
(The direction of the arrow (b)).

In the present invention, regardless of the specific material of the grinding wheel 24, any material suitable for grinding a wafer may be used. In general, it is preferable that the diamond grindstone is integrated with a binder.

The wafer holding table 14 also includes a fixed table 30 and a moving table 32. The fixed base 30 extends in the front-rear direction (the Y-axis direction in FIGS. 2 and 4; hereinafter, simply referred to as “Y-axis direction”) of the entire processing apparatus, and is fixed on the bed 10. The movable table 32 is slidably supported on the fixed table 30 in the Y-axis direction, and is slid in the Y-axis direction by a wafer feed motor 33 and a feed screw mechanism (not shown).

A pair of upper and lower support arms 34 extending in the Y-axis direction are fixed to the movable table 32, and a carrier 36 is fixed between the front ends of the support arms 34. As shown in FIG. 5A, the carrier 36 has a plate shape thinner than the wafer W to be processed, and has an arc-shaped inner peripheral surface 3 having the same radius of curvature as the radius of the wafer W.
6a. Further, since the taper surface tf is formed by chamfering the edges on both the front and back sides of the wafer W, the inner peripheral surface 36a is adjusted so that the taper surface tf and the inner peripheral surface 36a of the carrier 36 substantially match. It is formed in a V-groove shape.

At a position behind the carrier 36,
A cylinder device (clamp driving means) 38 is provided. The cylinder device 38 has a plurality of telescopic rods 39 that expand and contract in the Y-axis direction by supplying hydraulic or pneumatic pressure to the cylinder body. A fixed plate 40 is fixed to the front ends of these telescopic rods 39. A clamper holding member 42 extends forward (in a direction approaching the carrier 36) from the fixing plate 40, and a clamper 44 is fixed to a front end of the clamper holding member 42.

Like the carrier 36, the clamper 44 also has a plate shape thinner than the wafer W.
Has an arc-shaped inner peripheral surface 44a having the same radius of curvature as the radius of. Further, in order to make the tapered surface tf of the wafer W substantially coincide with the inner peripheral surface 44a of the clamper 44, the inner peripheral surface 44a is also formed in a V-groove shape. When the clamper 44 is driven forward by the operation of the cylinder device 38, the inner peripheral surface 44a of the clamper 44 and the inner peripheral surface 36a of the carrier 36 substantially match the outer tapered surface tf of the wafer W. In this state, the wafer W can be clamped (see the two-dot chain line in FIG. 5A).
Are transported integrally with the moving table 32 in the Y-axis direction.

Here, the arrangement positions of the carrier 36 and the clamper 44 in the X-axis direction are set at positions that match the intermediate positions of the two grinding wheels 24. Further, the axial dimension (vertical dimension in the illustrated example) of the two grinding wheels 24 is set to be equal to or larger than the diameter of the wafer W, and the entire area of both surfaces of the wafer W can be brought into contact with the two grinding wheels 24. The height position where the carrier 36 and the clamper 44 hold the wafer W is set so as to be as follows.

On the bed 10, a wafer supply table 46 is provided upright at a position halfway from a position where the carrier 36 and the clamper 44 are most retracted to a position between the two grinding wheels 24 as shown in FIG. . On the upper side of the wafer supply table 46, a suction portion 47 for suction-holding the wafer W is provided on one side surface (the right side surface in FIG. 3, the front side surface in FIG. 4).

A support column 48 is erected at an appropriate position on the bed 10, and a dressing device 50 according to the present invention is supported on the upper end of the support column 48. This dressing device 50
Is provided with a fixed table 52 and a lifting table 54, and the fixed table 5
Numeral 2 is fixed to the support column 48, and the elevating table 54 is supported by the fixing table 52 so as to be slidable in the vertical direction (Z-axis direction in FIG. 4), that is, to be able to move up and down.

From the elevating table 54, the grindstone holding rod 56 is directed downward.
A block-shaped dressing grindstone 58 as shown in FIG. 1 is fixed to the lower end of the grindstone holding rod 56. The X-axis direction of this dressing whetstone 58 (FIG. 1A)
Both ends protrude from both side surfaces of the grindstone holding rod 56, and the end surfaces (both side surfaces) are formed in a concave curved shape that matches the outer peripheral surface of each grinding wheel 24. Then, both side surfaces of the dressing grindstone 58 are the two grinding grindstones 2.
4 so as to be able to simultaneously contact the outer peripheral surface (see FIG. 2).
The position of the entire dressing apparatus 50 is set. Fixed base 5
2 is provided with a dress feed motor 60 at the top, and the dress feed motor 60 and a feed screw mechanism (not shown)
The lifting table 54, the grindstone holding bar 56, and the grindstone 5 for dressing
8 are integrally reciprocated up and down.

As the dressing grindstone 58, various grindstones conventionally known can be applied. As will be described later, alumina grindstone (A grindstone or WA grindstone) or silicon carbide grindstone is used. A grindstone having abrasive grains (C abrasive grains, GC abrasive grains, etc.) is particularly suitable.

This device is equipped with a control device 70 as shown in FIG. The control device 70 is composed of a computer or the like, and each motor 26, 28, 33, 6
The operation of these motors and the cylinder device 38 is controlled based on a detection signal output from an encoder incorporated in the microcomputer 0.

Next, the double-sided processing operation of the wafer W and the dressing operation of the two grinding wheels 24 performed under the control of the control device 70 will be described.

A) Processing Operation As an initial state, the moving table 18 of the grindstone table 12, the moving table 32 of the wafer holding table 14, and the clamper 44 are all retracted. That is, the grinding wheels 24 are largely separated from each other,
The carrier 36 and the clamper 44 are positioned rearward of the suction unit 47, and the clamper 44 is largely separated rearward from the carrier 36. The dressing grindstone 58 of the dressing device 50 is retracted to a position above the grinding grindstones 24.

The movable table 32 is advanced by operating the wafer feed motor 33, and the arc-shaped inner peripheral surface 36 of the carrier 36 is
It stops at the position where the center of a has passed the center of the suction part 47.

The wafer W cut out by a slicing device (not shown) is carried, and the wafer W is sucked by the suction unit 47.

The cylinder device 38 is operated to advance the clamper 44, and the clamper 44 and the carrier 3 are moved forward.
6 clamps the wafer W from the outside in the diameter direction (the state shown by the two-dot chain line in FIG. 1A). After this clamping, the suction by the suction section 47 is stopped.

The operation of each of the grinding wheel drive motors 26 drives the grinding wheel 24 to rotate, and the two grinding wheel bases 12
Is moved forward so that the grinding wheels 24 approach each other, and the gap between the two grinding wheels 24 matches the size corresponding to the target thickness dimension of the wafer W (<current thickness dimension).

In the state described above, the moving table 32 of the wafer holding table 14 is further advanced. Here, since the carrier 36 and the clamper 44, which are clamping members, are thinner than the wafer W, the carrier 36 and the clamper 44 pass between the grinding wheels 24 without contacting the two grinding wheels 24, and the wafer W Grinding wheel 2 only on both sides
4 (the state shown in FIG. 5B). Thereby, both surfaces of the wafer W are simultaneously ground. Wafer W after processing
Are appropriately collected by an unillustrated collecting means. If the sharpness of the grinding wheel 24 becomes dull, the dressing device 50
The grinding wheel 2 for both grindings in the following procedure using the dressing grinding wheel 58 of
Dress 4.

B) Dressing Operation With the grinding wheels 24 separated sufficiently, the dressing wheel 58 is lowered to a position between them. And
The lower end surface of the dressing grindstone 58 is located at an intermediate height position M between the height position of the upper end surface and the height position of the lower end surface of both grinding whetstones 24.
The dressing grindstone 58 is stopped at the position (the position indicated by the solid line in FIG. 1A; the first end position) that has reached (FIG. 1A).

The grinding wheels 24 are brought closer to each other, and the outer peripheral surfaces of the upper halves are formed on both side surfaces 58 of the dressing wheel 58.
The two grinding wheels 24 are stopped when they come into contact with a (FIG. 1 (a) and (b)).

The dressing grindstone 58 is moved up and down while rotating the grinding wheels 24. Specifically, while the dressing grindstone 58 is stopped at the position indicated by the solid line in FIG. 1A (the first end position), the grinding grindstone 24 is rotated in the direction of the arrow in FIG. , Double grinding wheel 24
Are gradually approached, so that these grinding wheels 24
The outer peripheral surface of the upper half is cut by a predetermined amount (for example, 1 μm) (actually, the binder of the grinding wheel 24 is removed). Thereafter, the dressing grindstone 58 is lowered at a constant speed, and the dressing grindstone 58 is moved to the position indicated by the two-dot chain line in FIG.
That is, when the upper end height of the dressing grindstone 58 reaches a position (second end position) that matches the lower end height of the dressing grindstone 58 at the first end position, the dressing is stopped. After cutting the lower half of the grindstone 24 by an amount equal to the predetermined amount, the dressing grindstone 58 is raised again at the first end position.

By repeating such operations, the dressing of both grinding wheels 24 is performed at one time. In addition, since the dressing grindstone 58 is moved up and down as appropriate, both side surfaces of the dressing grindstone 58 are leveled in reverse by contact with the two grinding grindstones 24, and the outer peripheral surfaces of the both grinding grindstones 24 are accurately cylindrical. It will be dressed in a plane. That is, both grinding wheels 2
4 will be dressed so that its buses are exactly parallel. In particular, if the dressing grindstone 58 has the above-mentioned alumina-based abrasive grains or silicon carbide-based abrasive grains, when the dressing grindstone 58 moves up and down, the abrasive grains released from the dressing grindstone 58 are removed by the grinding grindstone. 24, it is easy to act evenly in the axial direction, and as a result, the parallelism between the generating lines of the grinding wheel 24 is further improved.

The vertical movement stroke of the dressing grindstone 58 may be set as appropriate, but the dress area D by the dressing grindstone 58 at the first end position as shown in FIG.
1 and the dress area D2 formed by the dressing grindstone 58 at the second end position as shown in FIG. 4B, the overlapped portion is cut more than the other portions. If the two terminal positions are separated to such an extent that the overlapping portion does not occur, a uniform dress can be realized in the axial direction, and thereby high parallelism between the buses can be obtained. More preferably, as described above, the lower end position of the dressing grindstone 58 at the first end position (the lower end position does not necessarily have to be the intermediate height position M of the grinding grindstone 24, and may be a position in the vicinity thereof. ) And the upper end position of the dressing grindstone 58 at the second end position, the first end position and the second end position (that is, the reciprocating end position) are preferably set. As a result, the dress area D1 and the dress area D2 can be continuous without overlapping, and as a result, more uniform dressing can be performed in the axial direction and higher parallelism can be realized.

Considering the surface properties of the dressing grindstone 58, a state in which a part of the dressing grindstone 58 deviates in the axial direction from the grinding grindstone 24 (that is, a state in which the dressing grindstone 58 is not in contact with the grinding grindstone 24). In (2), the loose abrasive particles in the deviated portion are easily removed by the supplied coolant or the like, whereas in the portion where the dressing grindstone 58 and the grinding grindstone 24 are in contact, the loose abrasive particles are loosened even when the coolant is supplied. The abrasive grains are hardly removed. For this reason,
When the stroke of the dressing grindstone 58 is small, that is, at the first end position shown in FIG.
FIG. 8B shows a portion A where 8 deviates from the grinding wheel 24.
When the dressing grindstone 58 deviates little from the grinding grindstone 24 at the second end position shown in (2), the intermediate portion C that always contacts the grinding grindstone 24 occurs regardless of the position of the dressing grindstone 58. In this case, the state of adhesion of free abrasive grains in the intermediate portion C and the state of adhesion of free abrasive particles in both portions A and B are significantly changed, and the surface properties of the dressing grindstone 58 are likely to be uneven.

Therefore, in order to make the surface texture of the dressing grindstone 58 uniform in the axial direction, the above-mentioned intermediate portion (constant contact portion)
It is effective to enlarge the portions A and B to the extent that C does not occur (in other words, to greatly separate the first end position and the second end position). By uniformizing the surface properties of the dressing grindstone 58 in this manner, a more uniform dress can be obtained, and as a result, the buses of the grinding grindstone 24 can be parallelized with higher accuracy.

By using the grinding wheel 24 dressed with such a high degree of parallelism, both sides of the wafer W can be ground simultaneously and with high precision. Therefore, the dressing method and apparatus can be effectively used not only when the sharpness of the grinding wheel 24 becomes dull, but also as a means for shaping the grinding wheel at a stage before use of the wafer processing apparatus.

The embodiment of the present invention is not limited to this, and may take the following form, for example.

(1) In the present invention, regardless of the arrangement direction of the grinding wheels 24, for example, both grinding wheels 24 may be arranged vertically and the wafer W may be passed horizontally between them. In this case, the dressing grindstone 58 may be reciprocated in the horizontal direction between the grinding grindstones 24.

(2) The processing apparatus to which the dressing method and apparatus according to the present invention is applied may be any apparatus provided with a pair of grinding wheels 24 that are driven to rotate, and holds a wafer during processing. There is no particular limitation on the means for transferring the sheet, the means for transporting the holding means, and the like. For example, when the wafer W is held in an upright state as shown in FIG. 4, the wafer W may be clamped from above and below. , May be clamped from either side. Alternatively, a circular through hole may be provided in the thin holding plate, the wafer W may be fitted into the through hole, and the wafer W may be transferred together with the holding plate. In this case, FIG. 7A shows a second embodiment.
As shown in (b), the peripheral edge of the through hole of the holding plate 36 can be bent in the thickness direction, for example, by radially inserting a slit 38 into the peripheral edge of the through hole. If the diameter of the wafer W can be increased, the mounting of the wafer W becomes easy.

(3) In the above embodiment, the dressing grindstone 58 is reciprocated by using the dressing drive motor 60, and the control device 70 which outputs a control signal to the dressing drive motor 60 causes the dressing grindstone 58 to rotate. Although stroke control is performed, a hydraulic cylinder having a certain stroke may be used, and a dressing grindstone 58 may be attached to the end of the telescopic rod of this hydraulic cylinder and reciprocated. Also in this case, by selecting a hydraulic cylinder having a stroke for reciprocating the dressing grindstone 58 between the first end position and the second end position as described above, the bus bars of both grinding wheels 24 can be raised. Can be parallel with precision.

[0048]

As described above, according to the present invention, a pair of grinding wheels are rotated, and a dressing wheel is sandwiched between the two grinding wheels so that both side surfaces of the dressing wheel are outer peripheral surfaces of the two grinding wheels. The two grinding wheels are moved closer to each other and the dressing wheel is reciprocated in a direction parallel to the rotation axis of both grinding wheels. In addition, there is an effect that the buses can be made parallel to each other with high accuracy to realize high-precision processing on both surfaces of the wafer.

Here, if the dressing grindstone having alumina-based abrasive grains or silicon carbide-based abrasive grains is used, the abrasive grains released from the grindstone during the axial movement thereof become the grinding wheel. By acting uniformly in the axial direction on the other hand, there is an effect that the parallelism between the bus bars of both grinding wheels can be further improved.

The dressing whetstone is reciprocated between a fixed first end position and a second end position, and the dressing area formed by the dressing whetstone at the first end position and the second end position. The two end positions are separated to such an extent that the dress area by the dressing grindstone at the end position does not overlap, or the portion where the dressing wheel contacts the grinding wheel at the first end position is ground at the second end position. By separating the two end positions to the extent that they do not come into contact with the grinding wheels, the dressing of the grinding wheels can be made more uniform in the axial direction, and the parallelism between the bus bars of both grinding wheels can be further increased. The effect is obtained.

[Brief description of the drawings]

FIG. 1A is a cross-sectional front view showing a state in which a pair of grinding wheels are simultaneously dressed with a dressing wheel in the first embodiment of the present invention, and FIG. 1B is a cross-sectional plan view showing the state. FIG.

FIG. 2 is an overall plan view of the wafer processing apparatus according to the first embodiment of the present invention.

FIG. 3 is an overall front view of the wafer processing apparatus according to the first embodiment of the present invention.

FIG. 4 is an overall perspective view of the wafer processing apparatus according to the first embodiment of the present invention.

FIG. 5A is a cross-sectional plan view showing a state in which a clamper approaches a wafer in the first embodiment of the present invention, and FIG. 5B is a view in which both sides of the wafer are clamped by the clamper and a carrier. FIG. 6 is a cross-sectional plan view showing a state in which is ground.

6A is an explanatory diagram illustrating an example of a first end position of a dressing grindstone, and FIG. 6B is an explanatory diagram illustrating an example of a second end position of a dressing grindstone.

7A is a cross-sectional view taken along the line AA of FIG. 7B, and FIG. 7B is a side view showing a state where the holding plate holds the wafer in the second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Grinding wheel stand 14 Wafer holding table 24 Grinding grindstone 26 Rotary drive motor (grinding stone driving means) 28 Grinding stone feed motor (grinding stone sending means) 33 Wafer feed motor (wafer sending means) 50 Dressing device (dress operating means) 58 Dressing grindstone 58a Both sides of dressing whetstone W wafer

Continued on the front page (72) Inventor: Fumihiko Hasegawa 150, Odakura Osaikura, Nishigo-mura, Nishishirakawa-gun, Fukushima Prefecture Inside the Shirakawa Plant, Shin-Etsu Semiconductor Co., Ltd. Semiconductor Corporation Shirakawa Factory

Claims (6)

[Claims] 1. A pair of grinding wheels having a cylindrical outer peripheral surface are arranged such that their rotation axes are parallel to each other, and a wafer is passed between the two grinding wheels while rotating the grinding wheels. A method of dressing a grindstone in a wafer double-side processing apparatus in which both surfaces are simultaneously brought into contact with the outer peripheral surfaces of both grindstones, wherein the two grindstones are rotated, and the dressing grindstone is placed between the two grindstones. While holding both sides of the dressing whetstone in contact with the outer peripheral surfaces of both grinding whetstones, the dressing whetstones are made to approach each other, and the dressing whetstone is reciprocated along a direction parallel to the rotation axis of both grinding whetstones. A method of dressing a grindstone in a wafer double-side processing apparatus, characterized by moving the wafer. 2. The method for dressing a grindstone in a wafer double-side processing apparatus according to claim 1, wherein a whetstone having alumina abrasive grains or silicon carbide abrasive grains is used as the dressing grindstone. Dressing method of whetstone in double-sided processing equipment. 3. A method for dressing a grindstone in a wafer double-side processing apparatus according to claim 1, wherein the dressing grindstone is reciprocated between a fixed first end position and a second end position. And both end positions are separated to such an extent that the dress area by the dressing grindstone at the first end position and the dress area by the dressing grindstone at the second end position do not overlap. How to dress the whetstone in the device. 4. The method of dressing a grindstone in a wafer double-side processing apparatus according to claim 1, wherein the dressing grindstone is positioned between a first end position and a second end position. The wafer is reciprocated at the first end position, and the two end positions are separated to such an extent that the portion where the dressing grindstone contacts the grinding wheel at the first end position does not contact the grinding wheel at the second end position. Dressing method in a double-sided processing device. 5. A pair of grinding wheels having a cylindrical outer peripheral surface are arranged so that their rotation axes are parallel to each other, and the wafer is passed between the two grinding wheels while rotating the grinding wheels. A dressing device for a grindstone in a double-sided wafer processing apparatus in which both surfaces are simultaneously brought into contact with the outer peripheral surfaces of both grinding grindstones, and grindstone transfer means for relatively moving the grinding grindstones in a direction of coming and going with each other, and A dressing whetstone that performs dressing by sliding contact with a grinding whetstone, and this dressing whetstone is placed between the two grinding whetstones in a direction parallel to the rotation axes of the two grinding whetstones. And a dress operation means for reciprocating the wafer. 6. A dressing apparatus for a grindstone in a wafer double-side processing apparatus according to claim 5, wherein the dressing grindstone is a grindstone having alumina abrasive grains or silicon carbide abrasive grains. Dressing device of whetstone in processing equipment.