JP4037532B2 - Double-side polishing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a double-side polishing apparatus.
Conventionally, as a double-side polishing apparatus, an external gear (hereinafter referred to as an “external gear”) and an internal gear (hereinafter referred to as an “internal gear”) are rotated at different angular velocities to process a material (hereinafter referred to as “workpiece”). The upper surface plate and the lower surface plate having the polishing surfaces arranged on the upper and lower sides of the carrier are rotated and revolved while sandwiching the workpiece from above and below and relative to the workpiece. There is one using a planetary gear mechanism that moves to and polishes. This double-sided polishing machine is used as a lapping machine (lapping machine) or a polishing machine, which has high accuracy and can polish both sides simultaneously, so that the processing time is short, and thin objects such as silicon wafers that are used as semiconductor chip materials can be polished. Suitable for
[0002]
[Prior art]
A configuration of a polishing apparatus using a conventional planetary gear mechanism will be described with reference to FIG.
112 is an upper surface plate and 114 is a lower surface plate. A polishing cloth (cross) is attached to each surface, and a polishing surface is formed by the polishing cloth. 116 is an external gear, and 118 is an internal gear. Reference numeral 120 denotes a carrier. The workpiece 121 is held in a through hole formed in the carrier 120, and the external gear 116 and the internal gear 118 are engaged with each other to rotate.
The upper surface plate 112 is connected to an upper surface plate turner 112a, and a gear 112c is provided at the tip of a shaft 112b suspended from the upper surface plate turner 112a. The gear 112c meshes with the idle gear 112d, and the idle gear 112d meshes with the gear 112e. The gear 112e is provided coaxially with the spindle 126 so as to rotate integrally with the spindle 126. The lower surface plate 114 is connected to a gear 114 b provided coaxially with the spindle 126 via a gear 114 a provided coaxially with the lower surface plate 114. The external gear 116 is connected to a transmission gear 116 b provided coaxially with the spindle 126 via a gear 116 a provided coaxially with the external gear 116. The internal gear 118 is connected to a transmission gear 118 b provided coaxially with the spindle 126 via a gear 118 a provided coaxially with the internal gear 118. That is, this polishing apparatus is a so-called 4-way drive system in which the external gear 116, the internal gear 118, the upper surface plate and the lower surface plates 112, 114 are rotationally driven by one drive device.
The spindle 126 is connected to a variable speed reducer 132. The variable speed reducer 132 is connected to a motor 134 via a belt 136, and controls the rotational speed of the spindle 126.
[0003]
According to the polishing apparatus using this planetary gear mechanism, for example, the rotation ratio between the gear 116a and the transmission gear 116b and the transmission with the gear 118a so that the angular speed of the internal gear 118 is larger than the angular speed of the external gear 116. When the rotation ratios of the gears 118b are set, the carrier 120 meshed between the external gear 116 and the internal gear 118 has the same direction as the rotation direction of the internal gear 118 (for example, “counterclockwise”). Revolves and rotates clockwise. Similarly, the lower surface plate 114 rotates counterclockwise, but the upper surface plate 112 rotates clockwise because of the idle gear 112d.
Depending on the polishing conditions, the rotation direction and rotation speed of the carrier 120 can be changed by setting the angular speeds of the external gear 116 and the internal gear 118.
[0004]
Further, a liquid abrasive containing abrasive grains or the like is supplied to the front and back polishing surfaces of the workpiece 121, and the workpiece 121 is suitably polished by the action of the liquid abrasive. In the polishing of a silicon wafer, a polishing agent (commonly referred to as “slurry”) in which abrasive grains are dispersed in an alkaline polishing liquid is usually supplied between the silicon wafer and the polishing surface of a polishing platen for polishing. The
As a method of supplying the liquid abrasive, the liquid abrasive is dropped from above using a pump power and gravity through an abrasive supply hole provided through the upper surface plate 112 in the vertical direction. It is generally made to supply. The liquid abrasive discharged from the abrasive supply hole is supplied to a polishing section where the polishing surface of the upper surface plate 112 and the workpiece 121 come into contact with each other to polish the workpiece 121 and between adjacent carriers 120. , And flows onto the polishing surface of the lower surface plate 114, and the polishing surface of the lower surface plate 114 and the work 121 come into contact with each other and are supplied to a polishing unit for polishing the work 121.
[0005]
FIG. 9 is a plan view for explaining an arrangement example of the carriers 120 according to the polishing apparatus of FIG. 8, and there is a gap A between the adjacent carriers 120. The gap A is present in a sufficiently wide area at both the inner diameter portion and the outer diameter portion, and the liquid abrasive is suitably supplied also onto the polishing surface of the lower surface plate 114. As described above, the liquid abrasive is sufficiently supplied to both surfaces of the workpiece 121 by a simple supply means from above.
According to this polishing apparatus, since the liquid abrasive can be suitably supplied and the carrier 120 can be moved in a complicated manner, polishing unevenness can be prevented and the workpiece 121 (for example, a silicon wafer) can be uniformly polished. Therefore, the flatness of the workpiece can be improved. Moreover, since both surfaces of the workpiece 121 can be polished simultaneously, the polishing efficiency can be improved.
[0006]
However, since the double-side polishing apparatus using the conventional planetary gear mechanism has a structure in which the carrier 120 moves between the external gear 116 and the internal gear 118, it can cope with the recent increase in size of the workpiece 121 such as a silicon wafer. Hateful. That is, it is impossible to make the diameter of the carrier 120 larger than the radius of the surface plate, and the polished surface of the surface plate cannot be used efficiently.
Moreover, in the double-side polishing apparatus using the conventional planetary gear mechanism, it is a complicated gear mechanism, and it is difficult to increase the size, and in order to manufacture a large apparatus, problems in materials, processing, arrangement space, etc. Cost increases in various aspects.
[0007]
Therefore, the applicant of the present application has developed the following double-side polishing apparatus as background art.
In other words, the double-side polishing apparatus sandwiches a carrier, which is a thin plate and has a through-hole, and a wafer, which is a plate-like work placed in the through-hole of the carrier, from above and below, and is relative to the wafer. A double-side polishing apparatus comprising an upper surface plate and a lower surface plate that move and polish in a moving manner, wherein the carrier is caused to perform a circular motion that does not rotate in a plane parallel to the surface of the carrier via a carrier holder, and the transparent plate. A carrier turning motion mechanism is provided for turning the wafer held between the upper surface plate and the lower surface plate in the hole. The upper surface plate and the lower surface plate are provided so as to rotate (rotate).
[0008]
In the double-side polishing apparatus having a carrier that makes a circular motion that does not rotate in the background art, seasoning (correction) on the polishing surfaces of the upper surface plate and the lower surface plate that contacts the work and polishes the surface of the work is described below. The following means can be considered.
First, after the polishing process, the upper surface plate is raised, the carrier for polishing is removed, and the carrier 60 for correction is set as shown in FIG. 7, and the polishing surface 14a of the upper surface plate and the lower surface plate is set. The correction ring 62 to be corrected in contact with 16a is inserted into the through hole 60a and held by the correction carrier 60. Then, both the polishing surfaces 14a and 16a are corrected by moving the correcting carrier 60 in the same manner as the polishing carrier.
For example, the correction ring 62 is fitted and held in a large-diameter through hole 60a formed in the correction carrier 60, and a through-hole 62a having a size corresponding to the diameter of the workpiece 10 is formed on the inner peripheral portion. It has a ring shape. The correction ring 62 can be made of a brush on both sides or made of glass or ceramics. According to the correction ring 62 which is a brush on both sides, abrasive grains and polishing debris deposited on both polishing surfaces 14a and 16a can be removed. In addition, according to the correction ring 62 made of glass, ceramics, or the like, both polished surfaces 14a and 16a that have been partially reduced can be corrected to be flat.
[0009]
[Problems to be solved by the invention]
However, the polishing surface correcting means in the double-side polishing apparatus of the background art has a problem that it is difficult to efficiently automate the correction process.
That is, in order to replace the polishing carrier and the correction carrier 60, the correction ring 62 must be inserted into the through hole 60a, which is time consuming and inefficient. Further, in order to automate the replacement process, a complicated mechanical device and its control device are required.
In the prior art shown in FIGS. 8 and 9 as well, the polishing carrier 120 disposed between the large upper platen 112 and the lower platen 114 is replaced with a correction carrier to replace the upper platen. And the polished surface of the lower surface plate is corrected. As described above, since the carrier for polishing and the carrier for correction are exchanged, it is difficult to efficiently automate the correction of the polishing surface. Further, since the drive mechanism is driven by one motor 134, the connection relationship between the upper surface plate 112, the lower surface plate 114 and the carrier 120 and the drive mechanism is complicated, and the connection relationship cannot be easily broken. It was an obstacle to automation.
[0010]
SUMMARY OF THE INVENTION An object of the present invention is to provide a double-side polishing apparatus that includes a carrier that moves in a circular motion that does not rotate, and that can automatically and efficiently correct the polishing surfaces of the upper and lower surface plates with a simple configuration. It is to provide.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises the following arrangement.
That is, the present invention sandwiches a carrier in which a through-hole is provided in a thin flat plate and a plate-like workpiece arranged in the through-hole of the carrier from above and below and moves relative to the workpiece. The upper surface plate and the lower surface plate to be polished, and the carrier is caused to perform a circular motion that does not rotate in a plane parallel to the surface of the carrier, and is held between the upper surface plate and the lower surface plate in the through hole. A carrier revolving mechanism for reciprocating a workpiece; an upper platen elevating device for elevating and lowering the upper surface plate with respect to the carrier; and a mechanism for bringing the carrier into and out of contact with the lower surface plate. A raising and lowering device for the carrier to be moved up and down, provided in a movable manner between the upper surface plate and the carrier, for correcting the polishing surface of the upper surface plate, and provided in a movable manner between the lower surface plate and the carrier. To correct the polished surface of the lower surface plate Double-side polishing apparatus, characterized in that it comprises a stage.
[0012]
Moreover, it can be easily and suitably configured by the correction means being a spray nozzle that ejects a brush and / or a pressure fluid and sprays it onto the polishing surface.
[0013]
Further, the upper surface plate and the lower surface plate are driven to rotate around an axis parallel to a direction perpendicular to the surface of the carrier, so that the workpiece and the upper surface plate and the lower surface plate move relatively complicatedly. The polishing accuracy can be improved.
[0014]
The carrier turning mechanism includes a carrier holder for holding the carrier, a shaft on a holder side whose axis is parallel to a direction perpendicular to the surface of the carrier and is pivotally attached to the carrier holder, and the holder A base-side shaft that is parallel to the shaft on the side and that is pivotally attached to the base at a predetermined distance, and the carrier-side shaft is pivoted about the base-side axis to rotate the carrier holder. A carrier that is held by a carrier holder while having a simple structure by including a crank member that makes a circular motion that does not rotate with respect to the base, and a drive device that rotates the crank member about a base-side axis. It is possible to make a circular motion that does not rotate properly.
[0015]
Also, a plurality of the crank members are provided, and the base-side shafts are linked by a synchronizing means such as a timing chain so that the plurality of crank members are synchronously moved in a circular motion. Can be moved in a suitable and stable manner.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an exploded perspective view schematically showing an embodiment of the basic configuration of the double-side polishing apparatus of the present invention, and FIG. 2 shows the positional relationship of each configuration when the embodiment of FIG. 1 is operating. It is a sectional side view shown.
The present embodiment is a double-side polishing apparatus for polishing a silicon wafer 10 which is a plate-like workpiece, and is provided in a carrier 12 having a thin flat plate provided with a through hole 12a and disposed in the through hole of the carrier 12. An upper surface plate 14 and a lower surface plate 16 are provided that sandwich the wafer 10 from above and below and move relative to the wafer 10 for polishing. Abrasive cloths 14a and 16a called cloths are attached to the surfaces of the upper surface plate 14 and the lower surface plate 16, and a polishing surface is formed by the abrasive cloths 14a and 16a. Further, the upper surface plate 14 and the lower surface plate 16 of this embodiment are driven to rotate around an axis parallel to the direction orthogonal to the surface of the carrier 12.
The wafer 10 is circular and is loosely fitted in the circular through-hole 12a, and has a size that can rotate freely in the through-hole 12a.
The carrier 12 is generally formed of, for example, a glass epoxy plate and is set to have a thickness of about 0 or 7 mm with respect to a wafer 10 having a thickness of 0 or 8 mm.
[0017]
Reference numeral 20 denotes a carrier swivel movement mechanism that moves the carrier 12 in a plane parallel to the surface of the carrier 12 and is held between the upper surface plate 14 and the lower surface plate 16 in the through hole 12a. It is an example of the exercise | movement mechanism which moves.
The carrier turning motion mechanism 20 in this embodiment causes the carrier 12 to make a circular motion that does not rotate in a plane parallel to the surface of the carrier 12, and is held in the through hole 12 a so as to hold the upper surface plate 14 and the lower surface plate 16. The wafer 10 sandwiched by is rotated. That is, when the thickness of the carrier 12 is not considered, the carrier 12 is caused to perform a circular motion that does not rotate within the same plane as the surface of the carrier 12.
A specific configuration of the carrier turning motion mechanism 20 will be described below.
[0018]
A carrier holder 22 is formed in a ring shape and holds the carrier 12.
Here, the connecting means 50 for connecting the carrier 12 and the carrier holder 22 will be described. FIG. 3 is an explanatory view (a) is a plan view and (b) is a cross-sectional view) illustrating an example of the entire form of the carrier 12 and the carrier holder 22, and FIG. 4 is a view for explaining the operation of the connecting means of FIG. It is a principal part expanded sectional view.
The linking means 50 holds the carrier 12 by linking it to the carrier holder 22 so that the carrier 12 does not rotate and absorbs expansion due to thermal expansion of the carrier 12.
In the linking means 50 of this embodiment, as shown in FIG. 4, a pin 23 provided on the carrier holder 22 side, and an extension direction due to thermal expansion of the carrier 12 to the carrier 12 to be loosely fitted to the pin 23 (this embodiment) In the example, a hole 12b is formed with a clearance provided in the radial direction of the circular carrier 12. The clearance of the hole 12b may be suitably provided at least in the direction of absorbing the elongation due to the thermal expansion of the carrier 12, and may be formed, for example, as a long hole.
[0019]
Further, in this embodiment, the carrier 12 is formed so that a clearance is generated between the carrier 12 and the inner peripheral surface 22a of the carrier holder 22 so that the carrier 12 can slide suitably when thermally expanded. That is, the outer diameter of the carrier 12 is smaller than the inner diameter of the inner peripheral surface 22a by a predetermined size.
As described above, the hole 12b of the carrier 12 provided with a clearance in consideration of the thermal expansion of the carrier 12 is directly set by fitting into the pin 23 of the carrier holder 22.
Thus, by providing the connecting means 50 for absorbing the elongation due to the thermal expansion of the carrier 12, the carrier 12 can be suitably connected to the carrier holder 22 in a state of being prevented from rotating with a simple configuration.
Thereby, the elongation of the carrier 12 can be suitably released and absorbed, and the deformation of the carrier 12 can be prevented. Further, since the carrier 12 is configured to be fitted by being fitted to the carrier holder 22, the work at the time of loading is simplified.
[0020]
Next, the height adjustment function of the carrier 12 provided in the carrier holder 22 will be described.
Reference numeral 23 a denotes a flange portion, which is integrally provided in a washer shape in the middle portion of the pin 23. The flange portion 23a is provided on the carrier holder 22 side and serves as a support portion that directly supports the carrier 12 so as to hold it. A screw portion 23b is provided below the flange portion 23a of the pin 23 so that the pin 23 can be attached to the lower step portion 22b of the carrier holder 22. The height of the flange portion 23a can be adjusted by adjusting the degree of screwing of the screw portion 23b to the lower step portion 22b of the carrier holder 22. By providing the flange portion 23a in this manner, the carrier 12 can be appropriately held by the carrier holder 22 by suitably adjusting the height position of the carrier 12.
[0021]
That is, by adjusting the height of the flange portion 23a, it is possible to suitably cope with a change in conditions such as when the polishing cloth 16a of the lower surface plate 16 is consumed and thinned, and the surface of the polishing cloth 16a of the lower surface plate 16 is almost the same. At the same height, the carrier 12 can be suitably held so as not to bend. Therefore, the carrier 12 can be suitably held horizontally, and polishing cracks of the wafer 10 and deterioration of the polishing accuracy can be prevented.
Further, the outer peripheral surface of the carrier 12 is partially received by the surface of the flange portion 23a, and the sliding due to the expansion and contraction of the carrier 12 can be suitably supported. That is, since the contact area between the outer peripheral surface (lower surface) of the carrier 12 and the upper surface on the carrier holder 22 side can be reduced, the sliding frictional resistance can be reduced, and the carrier 12 can slide suitably. Thereby, the expansion and contraction force due to heat or the like of the carrier 12 is preferably released, and the occurrence of distortion of the carrier 12 can be prevented.
[0022]
In the above-described embodiment, the support height of the carrier 12 is adjusted by adjusting the height of the flange portion 23a of the pin 23. However, the present invention is not limited to this, and the carrier 12 is set to a predetermined value. The structure is not particularly limited as long as it is a suitable means that can support the height of the film.
For example, a mechanism for raising and lowering the carrier holder 22 itself and providing a support for supporting the carrier 12 may be basically the upper surface of the lower step 22 b of the carrier holder 22. Of course, the upper surface of the lower step portion 22b may be provided with unevenness in order to improve slipperiness.
[0023]
Next, another connecting means according to the present invention will be described with reference to FIG. FIG. 5A is a plan view, and FIG. 5B is a cross-sectional view.
As is apparent from the figure, this embodiment differs from the previous embodiment only in the connecting means 50, which includes an internal gear-like engaged portion 52 provided on the carrier holder 22 side, It has an external gear-like engaging portion 42 provided on the carrier 12 side so as to engage the engaged portion 52 with play. That is, the gear provided on the outer periphery of the carrier 12 and the gear provided on the inner periphery of the ring-shaped carrier holder 22 are engaged with each other with play. This also allows the carrier 12 to be suitably linked to the carrier holder 22 with a simple configuration. Then, the same effect as in the above embodiment can be obtained.
[0024]
Next, based on FIG.1 and FIG.2, the Example concerning each structure of the carrier turning motion mechanism 20 is demonstrated.
Reference numeral 24 denotes a crank member, which has a shaft axis 24 a on the holder side that is parallel to the axis L of the upper surface plate 14 and the lower surface plate 16 and is pivotally attached to the carrier holder 22, and a shaft center on the shaft 24 a on the holder side. Are parallel to each other, and a base-side shaft 24b is attached to the base 30 (see FIG. 2) at a predetermined distance. That is, it is formed to have the same function as the crank arm of the crank mechanism.
In the present embodiment, the crank member 24 is arranged at four positions between the base body 30 and the carrier holder 22, supports the carrier holder 22, and rotates the holder-side shaft 24 a around the base-side shaft 24 b. Thus, the carrier holder 22 is caused to perform a circular motion that does not rotate with respect to the base body 30. The holder-side shaft 24 a is rotatably inserted into a bearing portion 22 c provided so as to protrude from the outer peripheral surface of the carrier holder 22. As a result, the carrier 12 rotates eccentrically from the axis L of the upper surface plate 14 and the lower surface plate 16 (circular motion that does not rotate). The radius of the turning circular motion is the same as the distance between the holder-side shaft 24a and the base-side shaft 24b (the distance of the eccentricity M), and all the points of the carrier 12 are drawn in the locus of the same small circle. Become.
[0025]
Reference numeral 28 denotes a timing chain, which is wound around sprockets 25 (four in this embodiment) fixed coaxially to the base shaft 24b of each crank member 24. The timing chain 28 and the four sprockets 25 constitute a synchronizing means that links and synchronizes the four base body side shafts 24b so that the four crank members 24 are synchronously moved in a circular motion. This synchronization means has a simple configuration and can move the carrier 12 in a suitable and stable manner. As a result, the polishing accuracy can be improved, and the flatness of the wafer can be improved. The synchronizing means is not limited to the present embodiment, and it is needless to say that a timing belt or a gear may be used.
Reference numeral 32 denotes a motor (for example, a geared motor), and 34 denotes an output gear fixed to the output shaft. The output gear 34 meshes with a gear 26 that is coaxially fixed to the shaft 24 b on the base body side of the crank member 24. As a result, a rotation drive device is configured to rotate the crank member 24 about the base-side shaft 24b.
[0026]
In addition, as a rotation drive device, the some motor (for example, electric motor) arrange | positioned corresponding to each crank member 24 can also be utilized. If it is an electric motor, the plurality of crank members 24 can be synchronously moved and the carrier 12 can be smoothly moved by being electrically synchronized.
In the present embodiment, the case where four crank members 24 are arranged has been described. However, the present invention is not limited to this, and the carrier holder 22 can be suitably supported if there are at least three crank members 24. .
Furthermore, if the moving body of the XY table that can obtain a two-dimensional motion by synthesizing two orthogonal linear motions and the carrier holder 22 can be integrated and moved, one crank member 24 can be moved. By driving, the carrier holder 22 can be circularly moved without rotating. That is, by being guided by guides extending on two orthogonal axes of the XY table, the moving body does not rotate, and the movement of the moving body is changed to the movement of the carrier holder 22 (circular movement not rotating). It can be suitably used.
Further, the XY table itself may be provided with driving means without using the crank member 24 at all. That is, by using an X-axis and Y-axis drive mechanism composed of a combination of a servo motor and a ball screw or a servo motor and a timing chain that directly drive the X-axis and Y-axis members, The integrated carrier holder 22 may be moved (a circular motion that does not rotate). In this case, at least two motors are used, but by controlling the motors, various two-dimensional motions that do not rotate can be obtained in addition to the swiveling circular motions, and the motions can be polished. Available to:
[0027]
Reference numeral 36 denotes a lower surface plate rotating motor, which is a power device for rotating the lower surface plate 16. For example, a geared motor can be used as in this embodiment, and its output shaft may be directly connected to the rotating shaft of the lower surface plate 16.
Reference numeral 38 denotes power means for rotating the upper surface plate, which rotates the upper surface plate 14.
If the lower surface plate rotation motor 36 and the upper surface plate rotation power means 38 can freely change the rotation direction and the rotation speed, they can flexibly respond to various polishing specifications.
In this double-side polishing apparatus, the wafer 10 disposed in the through-hole 12a of the carrier 12 is sandwiched between the upper surface plate 14 and the lower surface plate 16 as shown in FIG. . At this time, the force with which the wafer 10 is pinched is mainly due to the pressing means provided on the upper surface plate 14 side. For example, air pressure is used, the maximum pressure is the weight of the upper surface plate 14, and the pressure applied to the wafer 10 by the upper surface plate 14 is an air bag system that acts to reduce the pressure by increasing the air pressure. May be adjusted. In this airbag system, the pressure can be adjusted suitably and easily by controlling the air pressure. In addition to the pressurizing means, an elevating device 40 for elevating and lowering the upper surface plate 14 is provided on the upper surface plate 14 side, and operates when the wafer 10 is supplied and discharged.
[0028]
Next, a means for supplying a liquid abrasive will be described with reference to FIGS.
The upper surface plate 14 is in contact with the polishing surface 14 a of the upper surface plate 14 and the wafer 10, and a polishing agent supply hole 14 b that supplies slurry (liquid polishing agent) to a polishing portion that polishes the wafer 10. Is provided.
The abrasive supply hole 14b may be appropriately provided in such a size that the liquid abrasive can be sufficiently and uniformly supplied to the polishing portion of the wafer 10 and does not adversely affect the polishing. The number is not particularly limited. In this embodiment, a total of 21 abrasive supply holes 14b are arranged in a matrix so that the holes 14b are uniformly distributed on the upper surface plate 14, and each is provided with a small diameter. The abrasive supply hole 14b of this embodiment is provided through the upper surface plate 14 in the vertical direction.
Although not shown, a tube or the like is connected to the upper end of the abrasive supply hole 14b so that the liquid abrasive pumped up by a pump or the like is appropriately distributed and supplied. .
[0029]
Then, the liquid abrasive supplied from the abrasive supply hole 14b is passed through the carrier 12 so that the polishing surface 16a of the lower surface plate (lower surface plate 16) and the wafer 10 come into contact with each other, and the wafer 10 is removed. A communication hole 15 for supplying a liquid polishing liquid to the polishing portion to be polished is provided.
The communication hole 15 may be provided in an appropriate form at a position that does not affect the strength of the carrier 12, and the size, shape, or number thereof is not limited. In the embodiment shown in FIG. 3, a total of five circular communication holes 15 are formed in the center of the carrier 12 and between the through holes 12 a adjacent to each other in the circumferential direction of the carrier 12.
[0030]
According to the carrier 12, the liquid polishing liquid can be suitably supplied to both surfaces of the wafer 10 to be polished, and can be preferably polished. That is, the liquid polishing liquid can flow down from the communication hole 15 which is a hole formed in the carrier 12 and can sufficiently flow into the back surface of the wafer 10 (the surface in contact with the polishing surface 16a). For this reason, polishing conditions can be maintained uniformly and suitably, and both surfaces of the wafer 10 can be accurately polished.
The liquid polishing liquid supplied onto the polishing surface 16a sequentially overflows and is discharged from the polishing surface 16a in the outer peripheral direction, as in the case of the conventional double-side polishing apparatus, and further recovered and circulated as appropriate. .
[0031]
As shown in FIG. 1, reference numeral 62 denotes a roller, which is an example of a vibration preventing means that abuts on the upper surface plate 14 and prevents the upper surface plate 14 from shaking in a direction parallel to the surface of the carrier 12. is there. The roller 62 is rotatably mounted on a guide roller body (not shown) provided in the vicinity of the upper surface plate 14 on the base 30 so as to abut on the outer periphery 14c of the upper surface plate 14 as appropriate. The plurality of rollers 62 sandwich the upper surface plate 14 during the polishing process, thereby restricting the movement of the upper surface plate 14 in the direction parallel to the surface of the carrier 12 and preventing vibration.
[0032]
Next, based on FIG. 6, the Example of the correction means which is the characteristic structure of this invention is described. This embodiment is a correcting means for seasoning (correcting) the polished surfaces of the upper surface plate 14 and the lower surface plate 16 that contact the wafer 10 as a workpiece and polish the surface of the wafer. FIG. 6A is a plan view for explaining the operation of the correcting means, and FIG. 6B is a side view for explaining the positional relationship of the correcting means. In addition, about the structure same as the Example demonstrated above, the same code | symbol is attached | subjected and description is abbreviate | omitted.
Reference numeral 40 denotes a lifting device for the upper surface plate, which lifts and lowers the upper surface plate 14 so as to be in contact with and away from the carrier 12.
Reference numeral 65 denotes a carrier elevating device that elevates and lowers the carrier 12 with respect to the lower surface plate 16. In the present embodiment, the carrier holder 22 can be moved up and down, and the carrier 12 is lifted when the correction is made by brushing or the like, so that the lower platen 16 and the carrier 12 are spaced at a predetermined interval.
In addition, as each said raising / lowering means 40 and 65, what is necessary is just to use a reciprocating device, such as a well-known cylinder apparatus or a well-known linear motion guide, a ball screw, and an electric motor.
[0033]
Reference numeral 66 denotes correction means for the upper surface plate, which is provided between the upper surface plate 14 and the carrier 12 so as to be able to advance and retreat, and corrects the polishing surface 14 a of the upper surface plate 14.
68 is a lower surface plate correction means, which is provided between the lower surface plate 16 and the carrier 12 so as to be able to advance and retreat, and corrects the polishing surface 16a of the lower surface plate 16.
As each of the correction means 66 and 68 described above, for example, a brush and / or an injection nozzle that ejects a pressure fluid and sprays it onto the polishing surface can be used.
When the brush and the spray nozzle are shared, a brush portion may be provided around the spray nozzle, and the pressure fluid may be ejected inside the brush portion. If comprised in this way, it can accept | permit flowing out while the pressure fluid discharge | released from the injection nozzle can be prevented by the brush part. The pressure fluid is a liquid such as water or a gas such as air that has a high pressure. For example, a high-purity water that has a high cleanliness may be used. According to this pressure fluid, the abrasive grains adhering to the polishing surfaces 14a and 16a can be blown off and removed.
[0034]
Each of the correcting means 66 and 68 in the embodiment shown in FIG. 6 is assumed to be in contact with each of the polishing surfaces 14a and 16a, and 67 is a correcting member. The correction member 67 can be made of a brush whose surface is in contact with the polishing surface, or made of glass or ceramics. According to the correction member 67 whose contact surface is a brush, it is possible to remove abrasive grains and polishing debris deposited on both polishing surfaces 14a and 16a made of polishing cloth. In addition, according to the correction member 67 made of glass, ceramics, or the like, both the polished surfaces 14a and 16a that have been partially reduced can be corrected to be flat. In the case of the correction member 67 made of glass, ceramics, or the like, the polished surfaces 14a and 16a can be efficiently corrected by using a surface whose surface is appropriately rough such as a porous shape.
Note that suction can be used as a correction means for adjusting the polishing surfaces 14a and 16a, and in combination with the correction member 67, the accumulated abrasive grains and polishing debris may be sucked and removed.
[0035]
Reference numeral 69 denotes a rotating arm, which is provided in each of the correcting means 66 and 68, and each of the correcting members 67 and 67 of the brush (or other seasoning tool) is indicated by a solid line and a two-dot chain line in FIG. And swivel. That is, each of the rotating arms 69 and 69 is rotated about a rotating shaft 69 a provided on the base, and the correcting members 67 and 67 are moved in the radial direction of the upper surface plate 14 and the lower surface plate 16. Reference numeral 69b denotes a swing motor, which is a drive device that swings and swings the rotating arm 69.
Thus, while rotating each rotation arm 69 and 69 and rotating the upper surface plate 14 and the lower surface plate 16, the upper surface plate 14 and the lower surface plate 16 are brushed (corrected) separately. Although the correction member 67 moves only within a predetermined range by the rotating arm 69, since the upper surface plate 14 and the lower surface plate 16 rotate, the entire polishing surfaces 14a and 16a can be corrected.
[0036]
Thus, the polishing surfaces 14a and 16a can be efficiently corrected by the correction means 66 and 68 including the correction member 67 such as a brush without removing the carrier 12 for polishing.
Further, a complicated machine configuration such as a robot apparatus and control means are not required, and efficient correction processes such as brushing can be efficiently performed. As a result, the entire polishing apparatus system can be automated.
8 and 9, the conventional carrier 120 meshes with the external gear 116 and the internal gear 118 that rotate in a horizontal plane. However, it is difficult to move the carrier 120 up and down. As in the embodiment, it is difficult to correct the polished surface.
[0037]
Next, an example of how to use the double-side polishing apparatus according to the present invention will be described.
First, the case where the upper surface plate 14 and the lower surface plate 16 are rotated in the opposite direction with the same absolute value of the rotation speed without moving the carrier 12 will be described. That is, as shown in FIG. 1, for example, the upper surface plate 14 rotates clockwise and the lower surface plate 16 rotates counterclockwise. In this case, since frictional force acts in exactly the opposite direction, the kinetic forces cancel each other, and theoretically, both surfaces are polished while the wafer 10 is stopped. In this case, however, the peripheral speed of the upper surface plate 14 and the lower surface plate 16 increases toward the outer periphery. Accordingly, polishing is promoted at a portion farther from the portion corresponding to the axis L of the upper surface plate 14 and the lower surface plate 16 of the wafer 10, and the wafer 10 is not uniformly polished.
[0038]
Next, the polishing action by causing the carrier 12 to perform a circular motion that does not rotate by the motion mechanism having the above-described configuration will be described.
If only the circular motion of the carrier 12 that does not rotate without considering the rotation of the upper surface plate 14 and the lower surface plate 16 is considered, the circular motion that does not rotate is completely different at all points of the moving member (carrier 12). The same exercise will be done. This is a kind of oscillating motion in the sense that all the points have the same motion, and it can be considered that the locus of the oscillating motion is a circle.
Therefore, if the wafer 10 is swung through the carrier 12 that does not rotate and moves in a circular motion, both surfaces of the wafer 10 are uniformly polished if the action is limited to this motion.
[0039]
When the rotational motion of the upper surface plate 14 and the lower surface plate 16 and the circular motion of the carrier 12 that does not rotate are operated simultaneously, the wafer 10 is held rotatably in the through hole 12a. When the absolute values of the rotational speeds of the upper surface plate 14 and the lower surface plate 16 are different (when the rotational speed of the other surface plate is increased with respect to one surface plate), the wafer 10 has a higher rotational speed. Rotate in the direction of rotation of the side platen. That is, the wafer 10 rotates in a predetermined direction.
As the wafer 10 rotates in this way, the peripheral speed of the upper surface plate 14 and the lower surface plate 16 increases toward the outer periphery, but the influence can be eliminated and the wafer 10 is uniformly polished. it can.
In addition, in order to polish both surfaces of the wafer 10 uniformly, the rotational speeds of the upper surface plate 14 and the lower surface plate 16 may be controlled so that one of them alternately increases.
[0040]
Next, another example of how to use the double-side polishing apparatus according to the present invention will be described.
In the above embodiment, a case where a plurality of through holes 12a are provided and a plurality of workpieces (wafers 10) are simultaneously polished has been described. However, the present invention is not limited to this. For example, the carrier 12 has a large workpiece. Only one through hole 12a to be held can be provided and used as a polishing apparatus for polishing both surfaces of the large workpiece. In addition, as a large sized workpiece | work, there exists a workpiece | work, such as a rectangular glass plate used for a liquid crystal, or a wafer (circular shape) processed with a sheet.
In this case, the large workpiece is disposed almost entirely from the center of the carrier 12 to the vicinity of the periphery thereof. At this time, if the polishing is mainly performed using the circular motion that does not rotate by the carrier 12, and the rotation speeds of the upper surface plate 14 and the lower surface plate 16 are reduced to such an extent that uneven polishing does not occur, the entire surface of the workpiece is uniform. And it can grind | polish suitably. That is, in the upper surface plate 14 and the lower surface plate 16, the polishing action increases toward the outer periphery due to the difference in peripheral speed, but if the rotational speed is very slow compared to the circular motion of the carrier 12 that does not rotate, the polishing action is directly affected. Can be hardly involved. Then, rotating the upper surface plate 14 and the lower surface plate 16 constantly updates the surface plate surface in contact with the workpiece, and in order to improve the polishing action, such as supplying a liquid abrasive to the entire surface of the workpiece on average. It can contribute indirectly and favorably.
[0041]
Although the polishing apparatus has been described in the above embodiment, it is needless to say that the present invention can be suitably applied to a wrapping apparatus.
As described above, the present invention has been described in various ways with reference to preferred embodiments. However, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. That is.
[0042]
【The invention's effect】
According to the double-side polishing apparatus of the present invention, the upper surface plate and the carrier that moves in a circular motion that does not rotate are moved up and down, and the polishing surface of the upper surface plate is formed by a correction means that is movable between the upper surface plate and the carrier. In addition to the correction, the polishing surface of the lower surface plate is corrected by a correction means provided so as to be movable back and forth between the lower surface plate and the carrier, so that each polishing surface can be preferably corrected without removing the carrier.
Therefore, according to the present invention, it is possible to effectively and automatically correct each polished surface of the upper surface plate and the lower surface plate with a simple configuration.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of an embodiment of a double-side polishing apparatus according to the present invention.
FIG. 2 is a side sectional view of the embodiment of FIG.
FIGS. 3A and 3B are a plan view and a cross-sectional view showing the entire carrier and carrier holder of the embodiment of FIG.
FIG. 4 is a cross-sectional view for explaining a main part of the connecting means according to the present invention.
FIGS. 5A and 5B are a plan view and a sectional view showing another embodiment of the connecting means according to the present invention. FIGS.
FIGS. 6A and 6B are a plan view and a side view for explaining an embodiment of the correcting means according to the present invention. FIGS.
FIGS. 7A and 7B are a plan view and a side view for explaining correction means of the background art. FIGS.
FIG. 8 is a cross-sectional view illustrating a conventional technique.
FIG. 9 is a plan view for explaining the arrangement of carriers according to the prior art.
[Explanation of symbols]
10 wafers
12 Carrier
12a through hole
12b hole
14 Top plate
14a Polished surface
14b Abrasive supply hole
15 communication hole
16 Lower surface plate
16a Polished surface
20 Carrier turning mechanism
22 Carrier holder
23 pins
24 Crank member
24a Holder side shaft
24b Base side shaft
28 Timing Chain
30 substrate
32 motor
40 Upper platen lifting device
65 Lifting device for carrier
66 Correction means for upper surface plate
67 Correction member
68 Correction means for lower surface plate
69 Rotating arm

Claims (5)

A carrier in which a thin plate is provided with a through hole;
An upper surface plate and a lower surface plate that sandwich a plate-like workpiece disposed in the through-hole of the carrier from above and below and move relative to the workpiece to polish;
A carrier swivel motion mechanism for causing the carrier to perform a circular motion that does not rotate in a plane parallel to the surface of the carrier, and to swivel the workpiece held between the upper surface plate and the lower surface plate within the through hole; ,
An elevating device for the upper surface plate that elevates and lowers the upper surface plate with respect to the carrier; and
An elevating device for the carrier that elevates and lowers the carrier so as to contact and separate from the lower surface plate;
A correction means provided between the upper surface plate and the carrier so as to be movable back and forth, and correcting a polishing surface of the upper surface plate;
A double-side polishing apparatus provided with a correcting means provided so as to be movable back and forth between the lower surface plate and the carrier, and correcting a polishing surface of the lower surface plate. 2. The double-side polishing apparatus according to claim 1, wherein the correcting means is an injection nozzle that jets a brush and / or a pressure fluid to spray the pressure fluid on the polishing surface. The double-side polishing apparatus according to claim 1 or 2, wherein the upper surface plate and the lower surface plate are driven to rotate about an axis parallel to a direction orthogonal to the surface of the carrier. The carrier turning mechanism is
A carrier holder for holding the carrier;
A shaft on the holder side that is parallel to a direction perpendicular to the surface of the carrier and is axially attached to the carrier holder, and a base body that is parallel to the shaft on the holder side and that is parallel to the axis on the holder side at a predetermined distance. A crank member that has a base-side shaft that is pivotally attached to the base, and rotates the holder-side shaft around the base-side axis so that the carrier holder does not rotate with respect to the base.
4. The double-side polishing apparatus according to claim 1, further comprising a driving device that rotates the crank member about a base-side axis. 5. The crank member according to claim 4, wherein a plurality of the crank members are provided, and the shafts on the base side are connected by a synchronizing means such as a timing chain so that the plurality of crank members are synchronously moved in a circular motion. Double-side polishing equipment.

Images