JP4352909B2 - Polishing apparatus, carrier for polishing apparatus and polishing method - Google Patents

Description

  The present invention relates to a polishing apparatus for polishing a workpiece such as a substrate, and relates to a polishing apparatus for polishing one side or both sides of a workpiece.

  Electronic parts such as semiconductor parts, piezoelectric parts, and magnetic parts are manufactured on a thin substrate using a microfabrication technique. Such a substrate is usually manufactured by thinly cutting a single crystal ingot or the like and then polishing it using a polishing apparatus called a lapping apparatus or a polishing apparatus, and planarizing the surface.

  As a conventional polishing apparatus, for example, a double-side polishing apparatus as shown in Patent Document 1 is known. The double-side polishing apparatus disclosed in Patent Document 1 includes a planetary gear mechanism as shown in FIG. This double-side polishing apparatus has a holding hole 6 for holding a workpiece, which is a workpiece, and serves as carrier plates 5A, 5B, 5C, and 5D and carrier plates 5A, 5B, 5C, and 5D that function as planetary gears from above and below. An upper grindstone 1 and a lower grindstone 2 are arranged so as to be sandwiched. The carrier plates 5 </ b> A, 5 </ b> B, 5 </ b> C, and 5 </ b> D are held between the sun gear 4 and the annular internal gear 3 provided coaxially with the sun gear 4.

  As shown in FIG. 9, the sun gear 4 is rotated counterclockwise, and the internal gear 3 is rotated clockwise at an appropriate speed. Thereby, the carrier plates 5A, 5B, 5C, and 5D revolve around the sun gear 4 in the clockwise direction while rotating in the clockwise direction as indicated by arrows. By rotating the upper grindstone 1 and the lower grindstone 2 counterclockwise, for example, both surfaces of the work held by the carrier plates 5A, 5B, 5C, and 5D are polished by the upper grindstone 1 and the lower grindstone 2.

  In this double-side polishing apparatus, the carrier plates 5A, 5B, 5C, and 5D revolve while rotating. For this reason, a workpiece | work can be grind | polished uniformly. Moreover, there exists an advantage that a workpiece | work can contact the large area of the upper grindstone 1 and the lower grindstone 2, and it can prevent that the upper grindstone 1 and the lower grindstone 2 wear locally.

  As shown in FIG. 10, Patent Document 2 discloses a double-side polishing apparatus including an upper grindstone 1, a lower grindstone 2, and a carrier 6 sandwiched between the upper grindstone 1 and the lower grindstone 2. In this double-side polishing apparatus, the carrier 6 has a holding hole 7 for holding a workpiece, and the four corners of the carrier 6 are connected to the eccentric arm 8. When the eccentric arm 8 rotates, the carrier 6 performs a circular motion that does not rotate so that the entire carrier 6 moves in parallel in the plane and an arbitrary point in the plane draws a circle.

According to the double-side polishing apparatus shown in FIG. 10, since a large number of holding holes 7 can be provided in the carrier 6, a large number of substrates can be polished at a time.
Japanese Utility Model Publication No. 6-85724 JP-A-10-202511

  However, in the above-described double-side polishing apparatus of Patent Document 1, since the carrier plates 5A, 5B, 5C, and 5D function as planetary gears, the carrier plates 5A, 5B, and 5C that can be disposed between the internal gear 3 and the sun gear 4 are used. The number of 5Ds cannot be increased. In addition, since it is necessary to provide gears on the outer periphery of the carrier plates 5A, 5B, 5C, and 5D, the number of holding holes 6 provided in one carrier plate cannot be increased. For this reason, there are many dead spaces in which substrates cannot be placed, and there is a problem that many substrates cannot be polished at once.

  Further, since the internal gear 3, the sun gear 4, and the carrier plates 5A, 5B, 5C, and 5D are provided with gears, dust such as substrate dust generated by polishing tends to accumulate between the gears. Such dust is gradually detached from between the gears during polishing, and causes a scratch on the substrate.

  Further, the workpiece cannot be polished unless the carrier plates 5A, 5B, 5C, and 5D are thinner than the workpiece. For this reason, in order to polish a thin workpiece, the carrier plates 5A, 5B, 5C, and 5D also need to be thinned. However, since the carrier plates 5A, 5B, 5C, and 5D function as planetary gears, if the thickness is made too small, the mechanical strength necessary for the planetary gears cannot be secured, and they are easily deformed or destroyed. Problems arise. There also arises a problem that the gears of the carrier plates 5A, 5B, 5C, and 5D are easily worn.

  In the double-side polishing apparatus of Patent Document 2, since the planetary gear does not exist, the above-described problem does not occur. However, the carrier 6 only performs a circular motion that does not rotate in the plane so that an arbitrary point in the plane draws a circle. For this reason, the movement amount with respect to the upper grindstone 1 and the lower grindstone 2 of a workpiece | work is small, and the problem that the parallelism of the workpiece | work after grinding | polishing is not enough arises.

  Further, the double-side polishing apparatus of Patent Document 2 requires a mechanism for moving the entire carrier 6 in parallel. Since such a mechanism needs to drive the four corners of the carrier 6 at the same time, there arises a problem that the overall shape of the double-side polishing apparatus becomes large.

  An object of the present invention is to provide a polishing apparatus and a polishing method capable of solving at least one of the above problems of the prior art and polishing a thin workpiece.

  The polishing apparatus of the present invention has a polishing surface for polishing a plate-like workpiece, a first surface plate that rotates about a first axis, a side surface, and a center of a cross section perpendicular to the side surface. An eccentric roller that rotates about the first shaft at a different position, a center hole for inserting the eccentric roller, and a holding structure for holding the plate-like workpiece. A carrier disposed so that the held plate-like workpiece is in contact with the first surface plate; and a carrier rotating mechanism for rotating the carrier around the eccentric roller.

  In a preferred embodiment, the carrier has two parallel main surfaces, and the holding structure is a holding hole penetrating the two main surfaces.

  In a preferred embodiment, the polishing apparatus further includes a second surface plate that has a polishing surface for polishing a plate-like workpiece and rotates about a first axis, and the first constant plate. A board and the second surface plate are arranged so as to sandwich the carrier.

  In a preferred embodiment, the carrier and the carrier rotation mechanism each have engagement means for engaging with each other.

  In a preferred embodiment, the carrier rotation mechanism includes a ring-shaped member disposed around the first surface plate, and the ring-shaped member rotates about the first axis.

  In a preferred embodiment, the engagement means is at least one engagement protrusion and an engagement hole larger than the engagement protrusion, and the engagement protrusion and the engagement hole are ring-shaped of the carrier and the carrier rotation mechanism. It is provided on the member.

  In a preferred embodiment, the engagement means is a plurality of engagement protrusions and engagement holes, and the plurality of engagement holes are provided on a circle centered on the center of the center hole in the carrier. The plurality of engaging protrusions are provided on a ring-shaped member of the carrier rotating mechanism.

  In a preferred embodiment, the polishing surface of the first surface plate and the surface provided with the plurality of engagement protrusions of the ring-shaped member of the carrier rotating mechanism are substantially in the same plane.

  In a preferred embodiment, the radius of the plurality of engagement holes provided in the carrier is equal to or greater than the distance between the center of the cross section of the eccentric roller and the first shaft.

  In a preferred embodiment, the carrier has a plurality of the holding holes, and a plurality of supply holes for supplying an abrasive to the work held in the plurality of holding holes in the vicinity of the plurality of holding holes. Have.

  In a preferred embodiment, the first surface plate has a ring shape having an inner hole, and the eccentric roller is disposed in the inner hole.

  In a preferred embodiment, the eccentric roller and the ring-shaped member of the carrier rotation mechanism rotate in the same direction.

  In a preferred embodiment, the second surface plate rotates in a direction opposite to that of the first surface plate.

  In a preferred embodiment, the carrier has a reinforcing ring that can come into contact with the eccentric roller and the engaging protrusion around the engaging hole and the central hole, respectively.

  In addition, the substrate of the present invention is polished by any one of the above polishing apparatuses so that at least one surface of the substrate becomes flat as a plate-like workpiece.

  The carrier of the present invention has a polishing surface, and is disposed around the surface plate so as to be rotatable about the first axis and a surface plate that rotates about the first axis. Used in a polishing apparatus provided with a carrier rotation mechanism including a ring-shaped member provided with an engaging protrusion, and holds a plate-like workpiece. The carrier includes a circular plate, a central hole for engaging an eccentric roller that is eccentric to rotate about the first axis, and the plurality of engagement protrusions disposed near the outer periphery of the circular plate. A plurality of engaging holes to be engaged and a holding hole for holding the plate-like workpiece.

  Further, in the polishing method for a plate-like workpiece according to the present invention, the first surface plate having a polishing surface is rotated around the first axis so that one surface of the plate-like workpiece is in contact with the polishing surface. The carrier holding the plate-like workpiece is caused to make a circular motion around the first axis, and the carrier is rotated.

  In a preferred embodiment, the polishing method is such that both surfaces of the plate-shaped workpiece contact the first and second polishing surfaces while rotating a second surface plate having a polishing surface around the first axis. As described above, it is sandwiched between the first surface plate and the second surface plate.

  In a preferred embodiment, the polishing method rotates the second platen in a direction opposite to the first platen.

  Further, the substrate of the present invention is polished by any one of the above polishing methods so that at least one surface of the substrate becomes flat as a plate-like workpiece.

  According to the polishing apparatus and the polishing method of the present invention, many thin substrates can be simultaneously polished with high processing accuracy.

  Hereinafter, embodiments of a polishing apparatus and a polishing method of the present invention will be described. In the specification of the present application, “polishing” means an operation of cutting a main surface of a plate-like workpiece such as a substrate and / or an operation of finishing the surface smoothly. That is, “polishing” includes an operation defined by the word “grinding”.

  FIG. 1 is an exploded perspective view showing a main part of the polishing apparatus 10 in an exploded manner, and FIG. 2 is a cross-sectional view of the polishing apparatus 10. The polishing apparatus 10 rotates the first surface plate 11, the second surface plate 12, the carrier 13 sandwiched between the first surface plate 11 and the second surface plate 12, the eccentric roller 14, and the carrier 13. For this purpose, a ring-shaped member 15 which is a carrier rotation mechanism is provided.

  The first surface plate 11 and the second surface plate 12 include polishing surfaces 11a and 12a that face each other. The polishing surfaces 11a and 12a may be the surfaces of the polishing cloth affixed to the first surface plate 11 and the second surface plate 12, or may be surfaces such as a grindstone. The roughness of the polishing surfaces 11a and 12a can be arbitrarily selected depending on the state of the plate-like workpiece, how the plate-like workpiece is to be finished, and other purposes. The first surface plate 11 and the second surface plate 12 have ring shapes having center holes 11c and 12c, respectively, and an eccentric roller 14 is disposed in the center holes 11c and 12c.

  The ring-shaped member 15 is disposed outside the first surface plate 11, and includes an upper surface 15 a disposed on substantially the same plane as the polishing surface 11 a of the first surface plate 11. A plurality of engagement pins 15b serving as engagement protrusions are disposed on the upper surface 15a.

  The first surface plate 11, the second surface plate 12, the eccentric roller 14, and the ring-shaped member 15 can rotate in either direction around the first axis A1. In order to rotate these members, the polishing apparatus 10 includes, for example, a mechanism shown in FIG. As shown in FIG. 2, the first surface plate 11, the second surface plate 12, the eccentric roller 14, and the ring-shaped member 15 are gears 11 g, 12 g, 14 g and so on to rotate about the first axis A 1. 15g, respectively. The gears 11g, 12g, 14g, and 15g are mechanically coupled to the variable speed reducer 16. The polishing apparatus 10 includes a motor 17, and the driving force of the motor 17 is transmitted to the variable speed reducer 16 via the belt 18. The variable speed reducer 16 reduces the rotational speed of the motor 17 and transmits the rotational force to the gears 11g, 12g, 14g and 15g. The variable speed reducer 16 can independently control the rotation direction and rotation speed of the first surface plate 11, the second surface plate 12, the eccentric roller 14, and the ring-shaped member 15.

  As shown in FIG. 2, the polishing apparatus 10 includes an elevator 19 for moving up and down the second surface plate 12, and includes a polishing surface 11 a of the first surface plate 11 and a polishing surface 12 a of the second surface plate 12. Can be kept parallel and the second surface plate 12 can be fixed so that the interval between the polishing surface 11a and the polishing surface 12a can be set arbitrarily. Further, the carrier 13 sandwiched between the first surface plate 11 and the second surface plate 12 can be applied with an arbitrary force. The polishing surface 11a and the polishing surface 12a are orthogonal to the first axis A1.

  The polishing apparatus 10 having the structure as shown in FIG. 2 can be produced by modifying the polishing apparatus having the conventional planetary gear shown in FIG. Specifically, in the conventional polishing apparatus, the polishing apparatus 10 is manufactured by using the eccentric roller 14 instead of the sun gear 4 and using the ring-shaped member 15 having the engagement protrusion 15b instead of the internal gear 3. be able to. Alternatively, the first surface plate 11, the second surface plate 12, the eccentric roller 14, and the ring-shaped member 15 can be rotated as described above, and the position of the first surface plate 11 can be controlled. As described above, the polishing apparatus 10 may be designed using a rotating machine and an elevator. Although not shown in FIG. 2, a slurry supply mechanism for supplying a slurry in which polishing powder is dispersed in a liquid between the first surface plate 11 and the second surface plate 12 as in the conventional polishing apparatus. The polishing apparatus 10 is provided.

  FIG. 3 is a plan view of the first surface plate 11, the eccentric roller 14, and the ring-shaped member 15 in FIG. 1 as viewed from the second surface plate 12 side. As shown in FIG. 3, a plurality of engagement pins 15 b are provided on the upper surface 15 a of the ring-shaped member 15. The engaging pins 15b are preferably arranged at equiangular intervals on a circumference centered on the first axis A1. Further, the ring-shaped member 15 has a ring shape centered on the first axis A1, and rotates around the first axis A1 as described above. The first surface plate 11 also has a center hole 11c, has a ring shape centered on the first axis A1, and rotates around the first axis A1. As will be described later, since the carrier 13 is disposed across the polishing surface 11a of the first surface plate 11 and the upper surface 15a of the ring-shaped member 15, the polishing surface 11a and the upper surface 15a may be substantially in the same plane. preferable.

On the other hand, the eccentric roller 14 disposed in the center hole 11c of the first surface plate 11 has a circular cross section perpendicular to the side surface thereof, and the center thereof is on the second axis A2. The second axis A2 is not coincident with the first axis A1, apart from the first axis A1 by a distance r _d. For this reason, the eccentric roller 14 rotates as indicated by an arrow about the first axis A1 that is eccentric from the second axis A2 that is the central axis of the eccentric roller 14. The center hole 11c of the first surface plate 11 is formed in such a size that the eccentric roller 14 can rotate around the first axis A1. The shape of the cross section perpendicular to the side surface of the eccentric roller 14 may be a polygon, but the eccentric roller 14 serves as an axis of rotation of the carrier 13 as will be described later. For this reason, it is preferable that the shape of the cross section is circular because rotational friction is reduced.

  Next, the carrier 13 will be described with reference to FIG. As shown in FIG. 4, the carrier 13 has a rotation center C1 and is provided with a center hole 13c centered on the rotation center C1. An eccentric roller 14 is inserted into the center hole 13c, and the carrier 13 rotates about the eccentric roller 14 as an axis as described in detail below. For this reason, the center hole 13c has a size that allows the eccentric roller 14 to be inserted and is rotatable about the eccentric roller 14 as an axis.

A plurality of engagement holes 13b are provided in the vicinity of the outer periphery of the carrier 13 and on the circumference centered on the rotation center C1. The number of the engagement holes 13b is preferably equal to or greater than the number of the engagement pins 15b of the ring-shaped member 15. Further, the engaging hole 13b is preferably has a distance r _d or more of the radius of the first axis A1 shown in FIG. 3 and the second axis A2. When the engagement pin 15b is cylindrical, the engagement hole 13b is preferably at a distance r _d and the value of the sum over the radius of the cross section of the cylinder of the engaging pin 15b. In FIG. 3, when the eccentric roller 14 is removed and the rotation center C <b> 1 of the carrier 13 is placed on the first axis A <b> 1, each engagement pin 15 b is positioned at the center of the corresponding engagement hole 13 b of the carrier 13.

  A holding hole 13a is provided in a region between the center hole 13c and the engagement hole 13b. The holding hole 13a functions as a holding structure that holds a plate-like workpiece such as a substrate. One or more holding holes 13a can be provided. In order to polish many plate-like works at once, it is preferable to provide many holding holes 13a. Although eight holding holes 13a are shown in FIG. 4, eight or more holding holes 13a may be provided. A supply hole 13d for supplying the abrasive powder to the plate-like workpiece may be provided in the vicinity of the holding hole 13a. The holding hole 13 a, the engagement hole 13 b, the center hole 13 c, and the supply hole 13 d are through holes that reach the two main surfaces of the carrier 13.

  In general, the thickness of the carrier for holding the plate-like workpiece needs to be smaller than the thickness of the plate-like workpiece after polishing. However, according to the prior art, in order for the carrier to function as a planetary gear, a thickness capable of maintaining the mechanical strength required as a gear must be ensured, and a thin plate workpiece can be polished. It was difficult. On the other hand, according to the present invention, since no gear is provided on the carrier 13, the thickness of the carrier 13 can be reduced according to the required thickness of the plate-like workpiece. As a material that can be used as the carrier 13, various materials such as metals such as stainless steel and aluminum, various plastics, glass fibers, aramid fibers, and composite materials of carbon fibers and epoxy resins can be used.

  As long as the engagement hole 13b is arranged on the circumference centered on the rotation center C1, the outer shape of the carrier 13 may be circular or polygonal. However, it is preferable that the carrier 13 is formed in a circular shape because the rotational motion of the carrier 13 becomes smooth.

  FIG. 5 is a plan view showing a state in which the carrier 13 is arranged on the first surface plate 11. The operation of the carrier 13 will be described with reference to FIG. The carrier 13 is disposed on the first surface plate 11 so that the eccentric roller 14 is inserted into the center hole 13c. At this time, the engagement pins 15b provided on the ring-shaped member 15 are inserted into the engagement holes 13b of the carrier 13, respectively.

A plate-like workpiece 20 is disposed in the holding hole 13 a of the carrier 13. The polishing apparatus 10 according to the present invention includes, as a plate-like workpiece, a semiconductor substrate such as silicon or GaAs, a sapphire substrate, a glass substrate, a ceramic substrate such as AlTiC, a piezoelectric substrate such as LN (LiNbO ₃ ), LT (LiTaO ₃ ), or quartz. Etc. can be polished. It is preferable that the holding hole 13 a has a shape that substantially matches the outer shape and size of the plate-like workpiece 20. When polishing the rectangular plate-like workpiece 20, an adapter having a rectangular hole corresponding to the outer shape of the plate-like workpiece 20 and having a circular outer shape corresponding to the holding hole 13a is prepared, and the adapter is installed in the holding hole 13a. And the plate-like workpiece 20 may be disposed in a rectangular hole in the adapter.

First, consider the case where the eccentric roller 14 is rotated while the ring-shaped member 15 is stationary. When the eccentric roller 14 rotates about the eccentric first axis A1, the carrier 13 moves circularly about the first axis A1 in a plane parallel to the polishing surface 11a. The radius of the circular motion is r _d. Since the ring-shaped member 15 is stationary, the engaging pin 15b does not change its position. However, the radius of the engagement hole 13b provided in the carrier 13, since it is set to at least a distance r _d between the first axis A1 and second axis A2, even carrier 13 by a circular motion, Each engagement hole 13b makes a circular motion around the center of the engagement pin 15b in the engagement hole 13b, and the side wall of the engagement hole 13b comes into contact with the engagement pin 15b to prevent the circular movement of the carrier 13. It will never be done.

  Next, the ring-shaped member 15 is rotated in this state. As shown in FIG. 5, when the ring-shaped member 15 rotates about the first axis A1, at least one of the engagement pins 15b comes into contact with the side wall of the engagement hole 13b of the carrier 13, and the side wall is ring-shaped. A force that pushes the member 15 in the rotating direction works. For this reason, the carrier 13 rotates around the eccentric roller 14 around the second axis A2. Since the second axis A <b> 2 coincides with the center of the carrier 13, this rotation is a rotation motion of the carrier 13. Thus, the engagement hole 13 b and the engagement pin 15 b serve as engagement means, and the rotation of the ring-shaped member 15 is transmitted to the carrier 13.

  In the polishing apparatus 10 of the present invention, the rotation of the eccentric roller 14 and the rotation of the ring-shaped member 15 are simultaneously performed. Further, the first surface plate 11 and the second surface plate 12 are rotated about the first axis A1. As a result, the carrier 13 is caused to make a circular motion about the first axis A1 while the first surface plate 11 and the second surface plate 12 are rotated about the first axis A1, and the carrier 13 Can be rotated.

  The rotation direction of the first surface plate 11 and the second surface plate 12 may be the same as or different from the rotation direction of the eccentric roller 14 and the rotation direction of the ring-shaped member 15. However, it is preferable that the rotation direction of the first surface plate 11 and the rotation direction of the second surface plate 12 are different, and the rotation speed is different. By rotating the first surface plate 11 and the second surface plate 12 in this way, the plate-like workpiece 20 can be rotated in the holding hole 13a of the carrier 13, and the plate-like workpiece 20 is polished more uniformly. can do.

  The direction of rotation of the eccentric roller 14 and the direction of rotation of the ring-shaped member 15, in other words, the direction of circular motion about the first axis A <b> 1 of the carrier 13 and the direction of rotation of the carrier 13 may be the same. , May be different. When these two rotation directions are the same, the plate-like work can be rotated more smoothly in the holding hole 13a of the carrier 13, and the effect that the plate-like work can be uniformly polished can be obtained.

The distance r _d between the second axis A2 that is the center of the cross section of the eccentric roller 14 and the first axis A1 that is the axis around which the eccentric roller 14 rotates indicates the degree of eccentricity of the rotating shaft in the eccentric roller 14. As is apparent from FIG. 5, the distance r _d for even larger radius larger the circular motion around the first axis A1 of the carrier 13, the plate-like work held by the holding hole 13a of the carrier 13 is first 1 may come off from the surface plate 13. For this reason, when the outer diameter and inner diameter of the first surface plate 13 are set to l ₁ and l ₂ , respectively, the distance r _d , the outer diameter is set so that the plate-shaped workpiece does not come off the outer side or the inner side of the first surface plate 13. It is preferable to determine the position of the holding hole 13a provided in the carrier 13 in consideration of l ₁ and the inner diameter l ₂ . In addition, the radius of circular motion of the carrier 13 is increased so that the plate-like workpiece does not deviate from the polishing surface 11a of the first surface plate 11 and the polishing surface 12a of the second surface plate 11, and the polishing surface 11a and the polishing surface 12a. so that it is possible to polish the nearly whole plate work, it is preferable to set the distance r _d.

  As described above, according to the polishing apparatus 10, the carrier 13 can be made thin according to the required thickness of the plate-like workpiece. However, if the carrier 13 becomes too thin, the force received from the engagement pin 15b and the eccentric roller 14 in the portion around the engagement hole 13b that contacts the engagement pin 15b and the center hole 13c that engages the eccentric roller 14 is reduced. Therefore, the carrier 13 may be deformed. In such a case, as shown in FIG. 6, reinforcing rings 13e and 13f may be provided around the engaging hole 13b and the center hole 13c so as to contact the engaging pin 15b and the eccentric roller 14, respectively. Since the reinforcing rings 13e and 13f that come into contact with the engaging pin 15b and the eccentric roller 14 disperse the force received from the engaging pin 15b and the eccentric roller 14 on the joint surface between the reinforcing rings 13e and 13f and the carrier 13, the carrier 13 Deformation can be prevented. When the reinforcing rings 13e and 13f are provided on the carrier 13, the first surface plate 11 prevents the reinforcing rings 13e and 13f from entering the region sandwiched between the first surface plate 11 and the second surface plate 12. It is necessary to adjust the size of the second surface plate 12 and the positions of the center hole 13c and the engagement hole 13b provided in the carrier 13.

  As described above, according to the polishing apparatus 30, the carrier 13 is moved circularly about the first axis A1 while the first surface plate 11 and the second surface plate 12 are rotated about the first axis A1. And the carrier 13 can be rotated. Due to such movement, each plate-like work held in the holding hole 13 a of the carrier 13 moves greatly with respect to the polishing surface 11 a of the first surface plate 11 and the polishing surface 12 a of the second surface plate 12. Moreover, since both surfaces of a plate-like workpiece can be simultaneously polished using the first surface plate 11 and the second platen 12, a plate-like workpiece having a very high degree of parallelism can be obtained.

  Since the area of contact between the polishing surface 11a of the first surface plate 11 and the polishing surface 12a of the second surface plate 12 and the plate-like workpiece is large, the wear of the first surface plate 11 and the second surface plate 12 is also uniform. To occur. For this reason, the frequency which replaces the 1st surface plate 11 and the 2nd surface plate 12, or performs maintenance decreases, and productivity can be improved.

  In addition, since no gear is provided on the carrier 13, the problem that has occurred in the conventional polishing apparatus having a planetary gear can be solved. Specifically, since it is not necessary to provide a waste gap between the plate-like workpieces, many plate-like workpieces can be polished at a time. Moreover, since the strength as a gear is not required, the carrier 13 can be made thin and a thin plate-like workpiece can be polished. Since there are no gears, shavings do not stay and scratches on the plate-like workpiece can be reduced. The frequency of carrier wear and breakage can also be reduced. With a conventional polishing apparatus using a planetary gear, it was difficult to polish a plate-like workpiece having a thickness of 300 μm or less. However, according to the polishing apparatus 10 of the present invention, the material of the carrier 13 can be selected appropriately. Therefore, it is possible to polish a plate-shaped workpiece of about 100 μm.

  Further, the circular motion and the rotational motion of the carrier 13 are performed by the eccentric roller 14 and the ring-shaped member 15. Since the eccentric roller 14 and the ring-shaped member 15 are only rotating around the same axis as the first surface plate 11 and the second surface plate 12, the circular motion of the carrier 13 is achieved by a simple mechanism. And can achieve rotation.

(Example)
Hereinafter, the Example which grind | polished the LN board | substrate as a plate-shaped workpiece | work using the grinding | polishing apparatus 10 of this invention is described.

  As the polishing apparatus 10, a conventional polishing apparatus having a planetary gear modified as described above was used. Twelve holding holes 13a were provided in the carrier 13 having a thickness of 180 μm, and an LN substrate having a diameter of 4 inches was polished from a thickness of 220 μm to a thickness of 210 μm. The polishing cloth was SUBA600 manufactured by Rodel Nitta Co., Ltd., and the polishing powder was EX2 manufactured by Fujimi Incorporated.

The rotational speeds of the first surface plate 11 (lower surface plate), the second surface plate 12 (upper surface plate), and the ring-shaped member 15 were 30, 15 and 10 rpm, respectively. In order to confirm the effect of the rotation of the eccentric roller 14, the rotational speed of the eccentric roller 14 was changed to 0, 5, and 10 rpm. The excess weight of the second surface plate 12 was set to 55 g / cm ² . The polished LN substrate was evaluated by measuring thickness variation (TTV). For comparison, the substrate was polished under the same conditions using a conventional polishing apparatus equipped with a planetary gear. In the conventional polishing apparatus, only five substrates can be polished at the same time.

  FIG. 7 shows the parallelism of the 12 LN substrates after polishing. When the eccentric roller 14 is not rotated (0 rpm), the thickness variation is about 1 μm, and the variation in the thickness variation value between the substrates is large. On the other hand, when the eccentric roller 14 is rotated at 5 rpm and 10 rpm, the thickness variation becomes small. When the eccentric roller 14 is rotated at 10 rpm, the thickness variation is 0.16 μm on average, and the deviation between the substrates is also small.

  FIG. 8 shows the polishing result of the substrate by the conventional apparatus and the apparatus of the present invention. The thickness variation and standard deviation of the substrate polished using the apparatus of the present invention are the same as or better than those of the conventional apparatus. As is apparent from the results, according to the apparatus of the present invention, it is possible to polish more substrates at the same time than the conventional apparatus, and to obtain a high polishing accuracy equivalent to or higher than that of the conventional apparatus. Can do.

  In the above-described embodiment, the carrier 13 has the holding hole 13a penetrating so that both main surfaces of the plate-like workpiece are polished. However, the polishing apparatus of the present invention can also be suitably used when polishing only one side of a plate-like workpiece. In this case, for example, a plate-like workpiece is attached to a holding plate having a thickness of about 10 to 20 mm, and a carrier having a thickness of about 10 mm is used. Then, the plate-like work affixed to the holding plate is arranged in the holding hole of the carrier so that the surface to be polished of the plate-like work is in contact with the polishing surface 11a of the first surface plate 11, and an appropriate one is placed on the holding plate. A load plate having a mass is placed. Thus, polishing can be performed while applying an appropriate load to the carrier without interfering with the movement of the carrier. By such a method, the surface of a substrate in which an electronic component is manufactured on one main surface side of a semiconductor device or the like can be protected with a photoresist or the like, and the back surface of the substrate can be polished.

  In the above embodiment, the engagement hole 13 b is provided in the carrier 13 and the engagement pin 15 b is provided in the ring member 15 as the engagement means for transmitting the rotation of the ring member 15 to the carrier 13. As another engagement means, an engagement protrusion may be provided on the carrier 13 and an engagement hole or an engagement recess for receiving the engagement protrusion may be provided in the ring-shaped member 15. There is no need to provide a plurality of engagement protrusions and engagement holes. If there are at least a pair of engagement protrusions and engagement holes, the rotation of the ring-shaped member 15 can be transmitted to the carrier 13.

It is a disassembled perspective view of the main components of the polisher of the present invention. It is sectional drawing of the grinding | polishing apparatus of this invention. In FIG. 1, it is the top view which looked at the 1st surface plate, the ring-shaped rotation member, and the eccentric roller from the 2nd surface plate side. It is a top view of a carrier. It is a top view which shows the state which has arrange | positioned the carrier on the 1st surface plate. It is a perspective view which shows the modification of a carrier. It is a graph which shows the result of having grind | polished a board | substrate using the grinding | polishing apparatus of this invention, Comprising: Thickness dispersion | variation when changing the rotational speed of an eccentric roller is shown. It is a graph which shows thickness dispersion | variation when a board | substrate is grind | polished using the grinding | polishing apparatus of this invention, and the conventional grinding | polishing apparatus, respectively. It is a perspective view which shows the conventional grinding | polishing apparatus. It is a perspective view which shows another conventional grinding | polishing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Polishing apparatus 11 1st surface plate 11a, 12a Polishing surface 12 2nd surface plate 13 Carrier 13a Holding hole 13b Engagement hole 13c Center hole 14 Eccentric roller 15 Ring-shaped rotating member 15b Engagement pin 16 Variable speed reducer 17 Motor

Claims (5)

While rotating the first surface plate having the polished surface around the first axis,
The carrier is arranged so that a plate-like workpiece held in the holding hole of a circular plate-like carrier having a center hole and a holding hole is in contact with the polishing surface,
By rotating an eccentric roller inserted into the center hole of the carrier and having the first shaft as an eccentric shaft, the carrier is caused to make a circular motion about the first shaft and is engaged with the carrier. A ring-shaped member disposed around the first surface plate, and rotating the carrier around the eccentric roller by rotating a ring-shaped member around the first axis. Polishing method.   The carrier has a plurality of engagement holes arranged in the vicinity of an outer periphery, and the ring-shaped member has a plurality of engagement protrusions that engage with the carrier by being inserted into the engagement holes. The method for polishing a plate-like workpiece as described. While rotating the second surface plate having a polishing surface around the first axis, the first work piece and the first surface plate are brought into contact with the polishing surfaces of the first and second surface plates. The plate-like workpiece polishing method according to claim 1, wherein the plate-like workpiece is sandwiched between a platen and the second platen.   The plate-like workpiece polishing method according to claim 3, wherein the second surface plate is rotated in a direction opposite to the first surface plate.   The plate workpiece polishing method according to claim 1, wherein the eccentric roller and the ring-shaped member are rotated in the same direction.

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