JP4693468B2 - Double-side polishing device with pressure roller for applying polishing pad - Google Patents

Description

The present invention relates to a double-side polishing equipment having a pressure roller for adhering the polishing pad to the platen.

  When polishing both the front and back surfaces of a thin workpiece such as a semiconductor wafer, a glass wafer used for a photomask, or a ceramic wafer, a double-side polishing apparatus such as a lapping apparatus or a polishing apparatus is used. This double-side polishing apparatus is generally positioned so as to surround the outer periphery of the lower surface plate, the upper and lower surface plates with the polishing pad attached to the annular pad attaching surface, the sun gear located in the center of the lower surface plate An internal gear and a plurality of carriers that are positioned on the lower surface plate and mesh with the two gears. The work is fitted and held in the work holding holes of each carrier, and the sun gear is rotated or the sun gear is rotated. And both the internal gear and the internal gear are rotated and revolved around the sun gear, and the front and back surfaces of the workpiece are polished with the polishing pads on the rotating upper and lower surface plates while supplying the polishing liquid. It is.

  In this type of double-side polishing apparatus, since the polishing pad is gradually worn or deformed with processing, it is necessary to replace the worn or deformed polishing pad with a new one at an appropriate time before the polishing accuracy decreases. is there. The replacement work is performed by peeling off the worn or deformed old polishing pad from the surface plate, and sticking the new polishing pad with a double-sided adhesive sheet. As described, it is common to use a pressure roller. The method is to press the pressure roller onto the polishing pad temporarily bonded to the surface plate and roll it, and press the entire pad with this pressure roller to press it against the surface plate. Are all done manually.

  However, when the diameter of the surface plate and the polishing pad is small, there is no problem. However, when the diameter of the surface plate and the polishing pad is increased as in the double-side polishing apparatus, the pressure roller is manually pressed evenly over the entire pad. Is very difficult, the polishing pad is misaligned to cause wrinkles, uneven adhesion occurs, air is trapped between the polishing pad and the surface plate, and irregularities are easily formed on the polishing pad. There was a problem.

  Accordingly, various techniques have been proposed that allow the polishing pad to be mechanically pressurized and attached. For example, Patent Document 2 discloses a method in which a polishing pad is mechanically pressurized and attached to the lower surface of an upper surface plate using a lower surface plate. In this method, a guide member on which a polishing pad is placed is interposed between upper and lower surface plates, and both surface plates are brought close to each other, whereby the guide member is pressed by the lower surface plate to place the polishing pad on the lower surface of the upper surface plate. It is to stick.

Patent Document 3 proposes a technique for mechanically pressing a polishing pad against a surface plate with a pressure roller. This technology is intended for single-side polishing equipment that presses a workpiece against a surface plate (base plate) with a pressure plate and polishes one side of the workpiece. A pressure roller is attached to the lower surface of the pressure plate, and pressure is applied with this pressure plate. By pressing the roller against the polishing pad, the polishing pad is pressed against the surface plate.
This method is very simple and efficient because it requires less labor than manual work and can uniformly pressurize the entire polishing pad in a short time.

Japanese Patent Laid-Open No. 11-151661 JP 2000-6011 A JP-A-11-320387

  However, since the technique described in Patent Document 2 presses the polishing pad with a surface through a pressurizing member, not only the pressurization is likely to vary, but also the polishing pad and the surface plate do not escape from bubbles. There is a drawback that it is easy to be contained during the period.

  Further, the technique described in Patent Document 3 is intended for a single-side polishing apparatus having only one surface plate, and the configuration of the apparatus is fundamentally different from a double-side polishing apparatus having two upper and lower surface plates. This technique cannot be directly applied to a double-side polishing apparatus. That is, when the technique of the single-side polishing apparatus is diverted to the double-side polishing apparatus, it is necessary to newly provide a pressure member corresponding to the pressure plate and hold the pressure roller on the pressure member. The fluid pressure cylinder and pressure control system must be added, and the pressure roller must be pressed against both the lower and upper surface plates. Not practical. In particular, it is not easy to install such a pressure member between the upper and lower surface plates, and press the polishing pad upward against the lower surface of the upper surface plate with the pressure roller so as to adhere. Further, when a plurality of pressurizing members are provided, it is necessary to further provide a pressure adjusting mechanism for equalizing the pressurizing force between them, which further complicates the structure. Further, when the pressing member is directly pressed against the pressing roller, the pressing roller may be difficult to rotate due to friction with the pressing member.

  Accordingly, an object of the present invention is to provide a new pad attachment that can be mechanically attached to the upper and lower surface plates of the double-side polishing apparatus using pressure rollers, and that is simple in configuration and easy to operate. Is to provide technical means.

In order to solve the above problems, according to the present invention, an annular pad adhering surface and an annular polishing pad adhering to the adhering surface are provided, and a workpiece held by a carrier is viewed from both sides. on surface plate and lower surface plate for polishing across, consist sun gear and the internal gear for driving the carrier, the roller body in which the cylindrical, a roller shaft for rotatably supporting the roller body, the actuator It is attached to the main body of the apparatus via a support mechanism that is driven by the actuator , and the support mechanism is driven by the actuator, so that the roller body rotates in the radial direction between the upper and lower surface plates. A polishing pad having a pad adhering position that pressurizes the polishing pad while following and rotating, and a pressure roller that displaces between a storage position away from the upper and lower surface plates Double-side polishing apparatus having a pressure roller is provided.

  In the present invention, the base end portion of the roller shaft is supported by the support mechanism so as to be able to move up and down and turn, and the locking receiving portion of the apparatus main body at the pad adhering position on the tip end portion of the roller shaft. A locking portion is formed to be locked to.

  Preferably, in the present invention, the roller body of the pressure roller has a length equal to or greater than the width of the pad adhering surface, and is in contact with the polishing pad on the pad adhering surface over the entire width. It is configured.

  Alternatively, the roller body of the pressure roller has a length shorter than the width of the pad adhering surface, partially contacts the polishing pad on the pad adhering surface, and rotates the upper and lower surface plates The platen may be configured to move in the radial direction of the surface plate while following and rotating.

According to the present invention, the pressure roller is interposed between the upper and lower surface plates, and a very simple technical means of rotating both surface plates in opposite directions with a load applied by the upper surface plate, The polishing pad can be mechanically pressed by the pressure roller to be pressure-bonded to the surface plate. In this case, the upper and lower surface plates are rotated in the opposite directions and the pressure roller is driven to rotate so that the pressure roller does not rub against the upper and lower surface polishing pads, and the polishing pad is damaged. It is possible to prevent the occurrence of wear or clogging.
In addition, since the entire pressure roller is simultaneously and evenly pressed by the upper and lower surface plates, the pressure applied by the pressure roller acts evenly on the entire polishing pad, so that uneven adhesion does not occur. The entire polishing pad can be uniformly adhered to the surface plate.
Furthermore, by attaching the pressure roller to the main body of the polishing apparatus with a support mechanism, the pressure roller can be easily operated to the pad adhering position and the storage position.

  FIG. 1 schematically shows a cross section of a main part of a double-side polishing apparatus. This double-side polishing apparatus is used for a thin plate-like workpiece such as a semiconductor wafer, a glass wafer used for a photomask, or a ceramic wafer. It is for polishing both the front and back surfaces, and is represented by a lapping device or a polishing device.

  As can be seen from FIGS. 2 and 3, the double-side polishing apparatus includes annular upper and lower surface plates 1 and 2 that are coaxially positioned, a sun gear 3 that is positioned at the center of the lower surface plate 2, and the lower surface plate 2. An internal gear 4 positioned so as to surround the outer periphery of each of the two surface plates 1 and 2 and at least the sun gear 3 of the two gears 3 and 4 are respectively connected to the drive shafts 11, 12, 13, It is connected to a motor (not shown) via 14 and is individually rotated at a required speed in a required direction.

  The upper and lower surface plates 1 and 2 are detachable by being attached to the surface plate supports 6 and 7, respectively. Of these, the upper surface plate 1 is attached to the rod 9 of the lifting cylinder through the surface plate receiver 6 and the surface plate suspension 8, and can be moved up and down by the lifting cylinder, and is described later when polishing a workpiece or will be described later. When the upper surface plate 1 is lowered when the polishing pad is replaced or the like, the hook 8a attached to the surface plate suspension 8 is engaged with the driver 11a at the upper end of the drive shaft 11, and is rotationally driven through the driver 11a. It has become so.

  The upper surface plate 1 and the lower surface plate 2 have ring-shaped pad adhering surfaces 1a and 2a on the lower surface or upper surface thereof, and the pad adhering surfaces 1a and 2a have a substantially uniform thickness as a whole. An annular polishing pad 5 is attached via a double-sided adhesive sheet bonded to the entire back surface of the polishing pad 5. The inner and outer diameters of the pad attachment surfaces 1a and 2a in the two surface plates 1 and 2 are the same, and therefore the inner and outer diameters of the polishing pads 5 and 5 attached to the two surface plates 1 and 2 are also the same. They are the same as each other. In addition, as said polishing pad 5, the thing made from a hard urethane or a hard nonwoven fabric can be used, for example.

  The sun gear 3 and the internal gear 4 have a large number of pins 3b and 4b constituting teeth arranged vertically and annularly at a constant pitch on the outer periphery or inner periphery of the ring-shaped bases 3a and 4a. It has the form of a pin gear.

  When the workpiece is polished by the double-side polishing apparatus, a plurality of carriers 16 having teeth 16a on the outer periphery are placed on the lower surface plate 2 as shown in the left half of FIG. 1 and one carrier in FIG. They are arranged at approximately equal intervals and meshed with the two gears 3 and 4. Then, disc-shaped workpieces W are fitted and held in the plurality of workpiece holding holes 16b formed in each carrier 16, and the sun gear 3 is rotated or both the sun gear 3 and the internal gear 4 are connected. By rotating, the carrier 16 is rotated and revolved around the sun gear 3 while supplying a polishing liquid between the upper and lower surface plates 1 and 2, and the polishing pads 5 of these surface plates 1 and 2 rotating. 5, the front and back surfaces of the workpiece W are polished.

  The double-side polishing apparatus also includes a plurality of pressure rollers 20 </ b> A used when the polishing pad 5 is attached to the surface plates 1 and 2. The pressure roller 20A includes a cylindrical roller body 21 made of metal (preferably stainless steel or other non-ferrous metal which is not easily rusted) and a roller shaft 22 which rotatably supports the roller body 21 around an axis. And is attached to the main body of the apparatus via a support mechanism 25 that supports one end of the roller shaft, and the support mechanism 25 is driven to occupy the polishing pad attached as shown by a solid line in FIGS. A position between the pad adhering position X, which is a position, and a storage position Y, which is a position when the polishing pad is not adhering as indicated by a chain line in FIG. 2, is displaced.

  The support mechanism 25 includes an elevating actuator 26 composed of a fluid pressure cylinder and the like, and a turning actuator 27 attached to a rod 26 a of the elevating actuator 26. The base end portion of the roller shaft 22 of the roller 20A is attached. Then, as shown by the chain line in FIG. 3, the pressure roller 20A is attached to the pad by performing the lifting operation by the lifting actuator 26 and the turning operation by the turning actuator 27. It is displaced between the wearing position X and the storage position Y. The driving of the pressure roller 20A by the support mechanism 25 is performed by an automatic operation or a manual operation.

  The axial length of the roller body 21 in the pressure roller 20A is the same as or slightly smaller than the width of the annular pad adhering surfaces 1a, 2a on the upper and lower surface plates 1, 2 (and hence the width of the polishing pad 5). It is greatly formed. The outer peripheral surface of the roller body 21 is preferably coated with a fluororesin.

  Further, a locking portion 23 having a locking convex portion or a concave portion is formed at the tip of the roller shaft 22, whereas the polishing device main body has a convex portion of the locking portion 23. Or when the latch receiving part 24 provided with the recessed part or convex part which a recessed part latches is formed, and the pressure roller 20A occupies the said pad sticking position X, these latching parts 23 and a latch receiving part 24, the convex part and the concave part are engaged with each other. In the illustrated example, the locking receiving portion 24 is formed in the sun gear 3. In this case, the pin 3b of the sun gear 3 can also be used as the engagement receiving portion 24, and a recess such as a hole for engaging the pin 3b can be formed in the engagement portion 23 of the roller shaft 22.

  In the illustrated example, the three pressure rollers 20A and the support mechanisms 25 are arranged around the internal gear 4 at almost equal intervals. However, the number of the pressure rollers 20A and the support mechanisms 25 is two. Or four or more.

  The operation when the polishing pad 5 is adhered to the upper and lower surface plates 1 and 2 using the pressure roller 20A is as follows. Here, although the case where the polishing pad 5 is stuck on the upper and lower surface plates 1 and 2 at the same time is described, the operation when the polishing pad is stuck only on either one of the surface plates 1 or 2 is the same. is there.

  First, as shown in FIGS. 1 and 3, the upper surface plate 1 is raised to a position where it does not interfere with the work, and when an old polishing pad is adhered to the pad attachment surfaces of both surface plates 1, 2. The pad is peeled off, and a new polishing pad 5 is temporarily bonded with a double-sided adhesive sheet.

  When the temporary bonding of the new polishing pad 5 is completed, the pad sticking position X indicated by the solid line in FIGS. 2 and 3 is driven by driving the support mechanism 25 for each pressure roller in the storage position indicated by the chain line in FIG. Displace to. At the pad adhering position X, the pressure rollers 20A are arranged radially on the lower surface plate 2 with the axis line in the radial direction of the lower surface plate, and the roller body 21 is placed on the polishing pad 5 of the lower surface plate 2. Contact across the entire width. Further, the locking portion 23 at the tip of the roller shaft 22 is locked to the locking receiving portion 24 of the sun gear 3.

Next, as shown in FIG. 4, the upper surface plate 1 in the raised position is lowered to a position where the polishing pad 5 contacts the roller body 21 of the pressure roller 20A, and the upper and lower surface plates 1, 2 Necessary load (pressing force) is applied to the upper surface plate 1 while sandwiching the roller body 21. The optimum value of the load at this time is preferably about 3 to ²⁰ kg / cm ² , although the optimum value varies depending on the scale of the polishing apparatus and the type of the polishing pad 5. Thus, by applying a load to the roller main body 21 with the pressure roller 20A interposed between the upper and lower surface plates 1 and 2, the polishing pads 5 and 5 of the two surface plates 1 and 2 are applied to the roller main body 21 by the load. Will be pressed against the pad adhering surfaces 1a, 2a with a pressure corresponding to.

Then, the sun gear 3 and the internal gear 4 are fixed in a non-rotating state, and only the upper and lower surface plates 1 and 2 are rotated at a constant speed in opposite directions at a slow speed. As a result, the roller main body 21 of each pressure roller 20A follows the rotating surface plates at a fixed position, rotates around the roller shaft 22 and rotates together with the surface plates 1, 2. The polishing pads 5 and 5 are pressed and pressed against the pad attaching surfaces 1a and 2a.
When the polishing pads 5 and 5 are attached, the upper surface plate 1 is raised, and the pressure roller 20A is displaced to the storage position by the support mechanism 25.

  Thus, it is very simple and rational that a plurality of pressure rollers 20A are interposed between the upper and lower surface plates 1 and 2 and the both surface plates 1 and 2 are rotated in opposite directions while a load is applied. By the method, the polishing pads 5 and 5 of the upper and lower surface plates 1 and 2 can be mechanically pressed by the roller main body 21 of each pressure roller 20A and can be pressure-bonded to the pad attaching surface. In this case, the roller body 21 is driven to rotate by rotating the upper and lower surface plates 1 and 2 in the opposite direction, so that the roller body 21 is the polishing pad 5 of the upper and lower surface plates 1 and 2. 5 does not rub against each other, and the polishing pads 5 and 5 are not damaged, worn, or crushed. Moreover, since the entire roller body 21 is simultaneously and evenly pressed by the upper and lower surface plates 1 and 2, the pressure applied by the roller body 21 acts on the entire polishing pads 5 and 5 evenly. Unevenness of adhesion does not occur, and the entire pad can be uniformly attached to the surface plates 1 and 2.

  FIG. 5 shows a second embodiment of the present invention. The difference between the double-side polishing apparatus of the second embodiment and the double-side polishing apparatus of the first embodiment is that the roller body 21 of the pressure roller 20B is fixed. It is the point which is formed so that it may move along the roller shaft 22 while being formed in length shorter than the width | variety of the pad sticking surfaces 1a and 2a of the board | substrates 1 and 2. That is, a male screw is provided on the outer periphery of the roller shaft 22 in each pressure roller 20B, and a female screw that meshes with the male screw is provided on the inner periphery of the roller main body 21. When the pad is attached, the roller main body 21 is fixed vertically. The roller main body 21 moves along the roller shaft 22 as the follower rotation follows the rotation of the plates 1 and 2. At this time, the air intervening between the polishing pads 5 and 5 and the pad adhering surfaces 1a and 2a is pushed and moved by the roller body 21 and is not discharged between them.

  The preferred length of the roller body 21 in the pressure roller 20B is about 1/2 to 1/3 of the width of the pad adhering surfaces 1a and 2a, but other lengths may be used. Further, the roller main body 21 may be moved from the inner peripheral side of the surface plates 1 and 2 toward the outer peripheral side, or may be moved from the outer peripheral side toward the inner peripheral side when the pad is attached.

  Since the configurations and operations other than those described above and preferred modifications in the second embodiment are the same as those in the first embodiment, the same reference numerals as those in the first embodiment are assigned to the same identical components. The description is omitted.

  FIG. 6 shows a third embodiment of the present invention. The difference between the double-side polishing apparatus of the third embodiment and the double-side polishing apparatus of the second embodiment is that a plurality of pressure rollers 20C are different from the polishing apparatus. It is a point that can be detached individually.

  That is, as can be seen from FIG. 7, the pressure roller 20C has a roller main body 21 having a length shorter than the width of the pad adhering surfaces 1a and 2a of the surface plates 1 and 2 and the roller main body 12 so as to be rotatable. It has a roller 22 shaft that is movably supported, and locking portions 23a and 23b formed at both ends of the roller shaft 22, and these locking portions 23a and 23b are provided on the lower surface plate 2 of the polishing apparatus. It is attached to the polishing apparatus by being locked to locking receiving portions 24a and 24b formed on the inner and outer peripheral portions. In this case, two pressure rollers 20C may be used and these pressure rollers may be mounted in a line in the diameter direction of the surface plates 1 and 2, but preferably, as shown in FIG. One or more pressure rollers 20C are arranged radially at equal intervals.

  A male screw is provided on the outer periphery of the roller shaft 22, and a female screw meshing with the male screw is provided on the inner periphery of the roller body 21, and the roller body 21 rotates the upper and lower surface plates 1 and 2 when the pad is attached. The roller main body 21 moves along the roller shaft 22 as the follower rotation follows.

The engaging portions 23a and 23b have a configuration in which one or a plurality of engaging holes 28 are provided on the lower surface of the block-shaped member, and the engaging holes 28 are connected to the sun gear 3 and the internal gear. 4 is engaged with one or a plurality of pins 3b, 4b so as to be attached to the polishing apparatus. Therefore, the locking receiving portions 24 a and 24 b on the polishing apparatus side are constituted by the sun gear 3 and the pins 3 b and 4 b of the internal gear 4.
However, the locking portion and the locking receiving portion are not limited to this, and any locking pins and protrusions that have engaging protrusions and recesses such as pins, protrusions, or holes dedicated to locking can be used. The thing of such a form may be sufficient.

  Since the configuration and operation of the third embodiment other than those described above and the preferred modification are the same as those of the second embodiment, the same reference numerals as those of the second embodiment are assigned to the main same components. The description is omitted.

  In the above embodiment, the sun gear 3 and the internal gear 4 have a form as a pin gear, and teeth are formed by a large number of pins 3b, 4b, but like a normal spur gear, The inner and outer circumferences may be provided with linear teeth parallel to the central axis. Thus, when the sun gear 3 and the internal gear 4 are provided with straight teeth, the locking portions 23, 23a, 23b of the pressure rollers 20A, 20B, 20C are formed in the same tooth shape as the straight teeth. It is also possible to form the projections and depressions so that the projections and depressions mesh with the straight teeth of the sun gear 3 or the internal gear 4.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows schematically the principal part of 1st Embodiment of the double-side polish apparatus which concerns on this invention, Comprising: The right half is the state which has arrange | positioned the pressure roller in the pad sticking position, The left half is This is a state in which a carrier for holding a workpiece is provided. It is a top view of the state which removed the upper surface plate of the double-side polish apparatus of FIG. It is a principal part enlarged view of FIG. It is sectional drawing which shows the state at the time of sticking of a polishing pad. FIG. 3 shows a second embodiment of the double-side polishing apparatus according to the present invention, and is a plan view at the same position as FIG. 2. 3 shows a third embodiment of the double-side polishing apparatus according to the present invention, and is a plan view at the same position as in FIG. 2. FIG. It is a bottom view showing a pressure roller with a part of the middle omitted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper surface plate 2 Lower surface plate 1a, 2a Pad sticking surface 3 Sun gear 4 Internal gear 5 Polishing pad 16 Carrier 20A, 20B, 20C Pressure roller 21 Roller body 22 Roller shaft 23, 23a, 23b Locking part 24, 24a 24b Lock receiving portion 25 Support mechanism X Adhering position Y Storage position W Workpiece

Claims (4)

An upper surface plate and a lower surface plate that have an annular pad attachment surface and an annular polishing pad attached to the attachment surface, and polish by sandwiching a workpiece held by the carrier from both sides,
A sun gear and an internal gear for driving the carrier;
A cylindrical roller body and a roller shaft that rotatably supports the roller body are attached to the apparatus body via a support mechanism driven by an actuator , and the support mechanism is driven by the actuator . In the state where the roller body is interposed between the upper and lower surface plates in the radial direction, the pad attaching position that presses the polishing pad while following the rotation of both surface plates and following the rotation, and from the upper and lower surface plates A pressure roller that displaces between remote storage positions;
A double-side polishing apparatus provided with a pressure roller for a polishing pad.   A base end portion of the roller shaft is supported by the support mechanism so as to be movable up and down and swivelable, and is engaged with a distal end portion of the roller shaft at a pad receiving position of the roller main body at a latch receiving portion. The double-side polishing apparatus according to claim 1, wherein a stop portion is formed.   The roller body of the pressure roller has a length equal to or greater than the width of the pad adhering surface, and is configured to contact the polishing pad on the pad adhering surface over the entire width. The double-side polishing apparatus according to claim 1 or 2, characterized in that   The roller body of the pressure roller has a length shorter than the width of the pad attachment surface, partially abuts against the polishing pad on the pad attachment surface, and follows the rotation of the upper and lower surface plates The double-side polishing apparatus according to claim 1, wherein the double-side polishing apparatus is configured to move in the radial direction of the surface plate while being driven to rotate.

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