JP2019130652A - Single-sided polishing device - Google Patents

Abstract

To provide a single-sided polishing device in which a structure for transferring and removing weights relative to a workpiece is simplified, and in which handling work of the weights can be easily performed in short time.SOLUTION: A single-sided polishing device uses plural weights to press a workpiece W inside a work holder 105 disposed via an abrasive pad 104a on a surface table 104, and polishes one surface of the workpiece W using the abrasive pad 104a by rotating the surface table 104 and the workpiece W relative to each other. As the weights, plural kinds of split weights 110a-110c of different weights are prepared, and the split weights 110a-110c prearranged according to a prescribed load distribution outside the surface table 104 are transferrable collectively onto a top surface of the workpiece W according to a weight conveyance device.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a single-side polishing apparatus for polishing a workpiece such as a glass substrate or a semiconductor wafer, and more specifically, a technique for pressurizing a workpiece according to a predetermined load distribution against a polishing pad attached to the surface of a surface plate. It is about.

  In this kind of single-side polishing apparatus, there are various conventional techniques for uniformly polishing the workpiece by preventing the edge of the workpiece and particularly the four corners of the rectangular workpiece from being excessively polished from the central portion. Is provided.

For example, Patent Document 1 discloses a CMP (Chemical Mechanical Polishing) apparatus that presses against a polishing pad while applying a load to a suction pad to which a workpiece such as a wafer is sucked by a plurality of ring weights, and the polishing rate is the entire surface of the workpiece. The prior art is made uniform.
In Patent Document 2, a polishing pad is fixed to a lapping surface plate, a workpiece is placed on the surface, and a plurality of spherical pressure members are disposed on the upper surface of the polishing substrate via a protective sheet. A polishing apparatus is described that pressurizes a pressure member with a pressurizing weight to make the pressure applied to the workpiece uniform.
In Patent Document 3, a workpiece is sucked and placed on the surface of a work table, and a polishing pad disposed above the workpiece is pressed with a plurality of pressure bars via an elastic body, thereby applying pressure to the workpiece. A polishing apparatus for homogenizing is described.

Further, Patent Document 4 describes a polishing apparatus that generates a predetermined load distribution on a workpiece in accordance with uneven polishing of the workpiece caused by a change in the surface plate shape caused by polishing heat.
FIG. 9 is a side view showing the main part of this polishing apparatus, wherein 1 is a surface plate, 2 is a polishing pad, 3 is a load holder, 4 is a load holding member, 5 is a number of weights (loads), and 6 is A nozzle for supplying a polishing liquid, W is a workpiece. In FIG. 9, the weights 5 are all shown at the same height. However, as will be described later, in order to obtain a load distribution according to the shape of uneven polishing of the workpiece W, a plurality of types of weights having different heights (weights) are used. Can be used.

FIG. 10 exaggerates the polishing uneven shape W ′ of the workpiece W, and this polishing uneven shape W ′ can be obtained in advance by experiments. Further, x, y, and z are distances from the reference surface of the workpiece W, and a to d indicate regions where the uneven polishing shape W ′ exceeds the distances x, y, and z, respectively.
In Patent Document 4, four types of weights 5a to 5d having different weights according to the above regions a to d are arranged on the workpiece W to form a non-uniform load distribution, and the workpiece W is polished in this state. As a result, the uneven polishing shape W ′ is offset.

Next, FIGS. 11A to 11D show handling operations for transferring the weights 5a to 5d to predetermined positions on the workpiece W in Patent Document 4, and 7 is a load handling device, 7a. Is a handling part provided with a suction part for sucking the individual weights 5a to 5d.
When the weights 5a to 5d are transferred onto the workpiece W in order to offset the uneven polishing shape W ′ of FIG. 10, in order to prevent the handling unit 7a from mechanically interfering with the transferred weight, The suction part on the lower surface of the handling part 7a repeats suction and release in the order of the lowest (lightest) weights 5a to 5b → 5c → 5d to transfer the weights 5a to 5d onto the workpiece W. As a result, finally, as shown in FIG. 11D, the distribution of the weights 5a to 5d corresponding to the polishing uneven shape W ′ of FIG. 10 is configured.

JP 2004-122318 A (paragraphs [0019] to [0024], FIG. 1 and the like) JP 2001-9698 (paragraphs [0019] to [0023], FIG. 1 and the like) Japanese Patent No. 3326442 (paragraphs [0022] to [0031], FIG. 1, etc.) JP 2002-18701 A (paragraphs [0027] to [0047], FIGS. 1 to 4 and the like)

In the polishing apparatus described in Patent Document 1, the shapes and structures of a plurality of types of ring weights combined concentrically are complicated, which may increase the cost.
Further, in the polishing apparatus described in Patent Document 2, spherical members having the same weight are used as the plurality of pressure members. However, when polishing a rectangular workpiece, for example, the four corners of the workpiece tend to be excessively polished. For this corner, the pressure is reduced according to the planar position of the workpiece. However, it is difficult for the polishing apparatus disclosed in Patent Document 2.
In the polishing apparatus described in Patent Document 3, it is necessary to provide as many linear actuators, cylinder blocks, springs, and the like as the number of pressure bars to pressurize the pressure bars, which complicates the structure of the apparatus. is there.

In the polishing apparatus described in Patent Document 4, it is necessary to provide as many suction portions as the handling parts 7a as many as the number of weights, so that the structure of the load handling apparatus 7 becomes complicated. Further, when changing the weight arrangement, basically, all the weights must be removed and then transferred onto the workpiece in order from the lighter weight.
Furthermore, assuming a case where a plurality of workpieces are continuously polished, a number of weights are removed in order from the heaviest after the polishing of one workpiece is finished, and after the polished workpiece is taken out, the next workpiece is removed. It is necessary to sequentially perform operations such as loading onto a polishing pad and then transferring a large number of weights onto a workpiece in order from a light weight.
That is, in the polishing apparatus of Patent Document 4, the structure of the load handling apparatus 7 is complicated, and work such as weight transfer and removal is complicated and takes a long time, so that a series of polishing workability is poor. There was a problem.

  SUMMARY OF THE INVENTION Accordingly, the problem to be solved by the present invention is to provide a single-side polishing apparatus that simplifies the structure for transferring and removing weights to and from the workpiece, and that can easily perform weight handling operations in a short time. It is in.

In order to solve the above-mentioned problem, the invention according to claim 1 is directed to pressurize a work in a work holder arranged on a surface plate via a polishing pad with a plurality of weights, and to make the surface plate and the work relatively A single-side polishing apparatus for rotating one surface of the workpiece with the polishing pad,
As the weight, a plurality of divided weights having different weights are prepared,
The plurality of divided weights arranged in advance according to a predetermined load distribution outside the surface plate can be collectively transferred to the upper surface of the work in the work holder by a weight conveying device.

  According to a second aspect of the present invention, in the single-side polishing apparatus according to the first aspect, the upper ends of the holding rods respectively holding the divided weights are supported by the retaining plate through the suspension plate, and the weight conveying device Is characterized in that the suspension plate and the retaining plate are gripped integrally and the divided weight is transferred to the upper surface of the workpiece.

  The invention according to claim 3 is the single-side polishing apparatus according to claim 2, wherein the retaining rod penetrating the suspension plate is slid relative to the suspension plate. The upper end can be locked in the locking hole of the retaining plate.

  According to a fourth aspect of the present invention, in the single-side polishing apparatus according to any one of the second or third aspects, positioning members are respectively disposed at both ends of the suspension plate, and the suspension plate is formed by these positioning members. The division weight is placed on the upper surface of the workpiece while positioning the retaining plate on the workpiece holder.

  The invention according to claim 5 is the single-side polishing apparatus according to claim 4, wherein the workpiece is polished in a state where the retaining plate and the suspension plate are positioned on the workpiece holder by the positioning member. To do.

According to the present invention, the structure is simpler than the pressurizing means and pressurizing mechanism in the polishing apparatus of Patent Documents 1 and 3, and the cost can be reduced. Further, it is possible to realize polishing with a predetermined load distribution, which was difficult with the polishing apparatus of Patent Document 2.
Furthermore, compared with the polishing apparatus described in Patent Document 4, the handling work for transferring and removing the weight to the workpiece can be performed in a short time, and the workability of the polishing process is greatly improved. be able to.
In addition, the heat radiation efficiency at the time of polishing is good, and there is an effect that the workpiece and the surface plate are not deformed by the polishing heat.

It is the top view and side sectional drawing of the principal part of embodiment of this invention. It is a perspective view of the principal part of embodiment of this invention. It is a perspective view of the principal part of embodiment of this invention. It is a side view of the principal part which shows the use condition of embodiment of this invention. It is a side view of the principal part at the time of using a uniform weight as a reference example. It is a top view which shows the example of arrangement | positioning of the division | segmentation weight in embodiment of this invention. It is a side view for demonstrating the setup operation | movement of the division | segmentation weight in embodiment of this invention. It is the top view and side view which show the whole structure of embodiment of this invention. It is sectional drawing which shows the principal part of the grinding | polishing apparatus described in patent document 4. It is a figure which shows arrangement | positioning of the weight according to the grinding | polishing nonuniformity shape of the workpiece | work in patent document 4. FIG. 10 is an explanatory diagram of a weight handling operation in Patent Document 4. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view (FIG. 1 (a)) and a side sectional view (FIG. 1 (b)) showing a main part of a single-side polishing apparatus according to an embodiment of the present invention. In these drawings, a surface plate 104 is disposed above the housing 101, and the surface plate 104 can be rotated about a rotation shaft 103 by a drive motor 102. A polishing pad is affixed to the surface of the surface plate 104, but is not shown for convenience.

A disk-shaped work holder 105 is placed on the upper surface of the surface plate 104, and a work W such as a rectangular substrate is accommodated in the central window portion thereof. As shown in FIG. 1A, the work holder 105 can be swung by moving a work holder rocking frame 111 arranged on the side in the direction of arrow a, and the work holder driving motor 115 can move the work holder 105. It can be rotated.
With the above configuration, the surface plate 104, the work holder 105, and the work W can be relatively rotated and swung.

As shown in FIG. 1B, a suspension plate 106 and a retaining plate 108 are disposed above the work holder 105 by a rod-shaped positioning member 107. In addition, a large number of divided weights 110 are held on the suspension plate 106 and the retaining plate 108 by holding bars 109, and these divided weights 110 press the work W in the work holder 105 from above.
A base weight 110x is arranged below the divided weight 110 as shown in FIG. 4 described later. However, in FIG. 1B, the base weight 110x is not shown for convenience.

In FIG. 1A, only the arrangement of the divided weights 110 is shown with the suspension plate 106, the retaining plate 108 and the like in FIG. 1B omitted. As shown in the drawing, each of the divided weights 110 has a rectangular parallelepiped shape when viewed from the plane, and the overall planar shape in which a large number of divided weights 110 are arranged vertically and horizontally substantially matches the outer shape of the workpiece W. Yes.
In addition to the method of changing the height of these divided weights 110, the weight is arbitrarily set by changing the number of unit weights of a certain height (weight) inserted from the upper part of the holding rod 109. , Can have multiple kinds of weight.

Next, FIG. 2 is a perspective view showing the arrangement of each member on the work holder 105. Suspension pieces 112 for supporting the work holder 105 from above are provided at four positions around the work holder 105.
Positioning members 107 arranged at four positions around the suspension plate 106 support the suspension plate 106 so as to be movable in the vertical direction by a pin-hozo structure, and also support the suspension plate 106 with respect to the work holder 105. Has the function of positioning.
2 and FIG. 3 to be described later, the illustration of the base weight 110x disposed below the divided weight 110 is omitted.
FIG. 3 is a perspective view showing the positional relationship between each member shown in FIG. 2 and the surface plate 104 and the work holder swing frame 111.

Next, FIG. 4 is a side view of the main part showing the use state of this embodiment.
When a rectangular workpiece W is polished, generally, the vicinity of the four corners of the workpiece W tends to be excessively polished, and the vicinity of the central portion tends to be insufficiently polished. Therefore, a plurality of types of divided weights 110a, 110b, and 110c (weight is 110a>110b> 110c) prepared with different weights by the above-described method are prepared, and from the center of the workpiece W toward the four corners. A large number of divided weights 110a to 110c are arranged so that the weight is gradually reduced. Thereby, it can grind | polish so that the thickness of the workpiece | work W may become uniform as a whole.

4A shows a state before the divided weights 110a to 110c and the base weight 110x held by the holding bar 109 are placed on the surface of the workpiece W, and before the positioning member 107 positions the workpiece weight 105 on the workpiece holder 105. FIG. State. FIG. 4B shows a state where the workpiece W is positioned by the positioning member 107 and the workpiece W is pressurized by the divided weights 110a to 110c and the base weight 110x.
The base weight 110x is fixed to the lower end portion of the holding rod 109, and the divided weights 110a to 110c are stacked on the base weight 110x by passing through the central through hole of the divided weights 110a to 110c from above. Is configured to do.

  As shown in FIG. 4A, the convex portion at the upper end of the holding rod 109 can penetrate the oval or circular locking hole 108a of the retaining plate 108 after passing through the through hole of the hanging plate 106. The retaining plate 108 is slid in the direction of the arrow b after passing through the locking hole 108a, so that the holding rod 109, the base weight 110x, and the divided weights 110a to 110c, 110x are suspended from the suspension plate 106 and the retaining plate 108. Can be integrally attached to each other.

  The positioning member 107 is provided with a posture adjusting unit 107a for adjusting the distance between the suspension plate 106 and the work holder 105 (work W). By adjusting the posture adjusting unit 107a to keep the posture of the suspending plate 106 parallel to the workpiece W, when the workpiece is positioned on the workpiece holder 105 by the positioning member 107 as shown in FIG. The lower surface of the base weight 110x is considered to be in contact with the surface of the workpiece W evenly and uniformly.

  Reference numeral 104 a denotes a polishing pad affixed to the upper surface of the surface plate 104, and reference numeral 105 a denotes a positioning recess that engages with a protrusion at the lower end of the positioning member 107. Reference numeral 113 denotes a buffer material made of a rubber plate or the like. The cushioning material 113 is placed on the upper surface of the workpiece W in advance so as to be approximately the same size as the entire upper surface of the workpiece W.

The distribution of the thickness of the workpiece W generated as the polishing progresses, that is, the state in which the thickness becomes nonuniform in the vicinity of the four corners and the central portion of the workpiece W can be confirmed in advance by an experiment. Accordingly, the planar arrangement of the divided weights 110a to 110c having different weights can be determined.
As shown in FIGS. 4 (a) and 4 (b), if the divided weights 110a, 110b, and 110c are sequentially arranged so that the weight decreases from the center of the workpiece W toward the four corners, the weight is increased as shown in FIG. Compared with the case of using a uniform weight 110 ′ having a uniform thickness, the thickness of the workpiece W after polishing becomes substantially uniform as a whole. In FIG. 5, 105 ′ is a work holder, and 113 ′ is a cushioning material.

  FIG. 6 is a plan view showing an example of arrangement of the divided weights 110a to 110c in this embodiment. When using the uniform weight 110 ′ as shown in FIG. 5, various uniform weights 110 ′ having different sizes and weights according to the size of the workpiece W and the set load must be prepared. It is difficult for the uniform weight 110 ′ to maintain the accuracy of the pressing surface with respect to the workpiece W.

In the present embodiment, a predetermined load distribution can be obtained by changing the number and arrangement of the divided weights 110a to 110c as shown in FIGS. 6A to 6E in accordance with the size of the work W and the set load. .
Incidentally, FIG. 6A is an example in which three types of divided weights 110a to 110c are arranged to pressurize the entire surface of a large workpiece W, and FIG. This is an example in which no divided weight is arranged at the four corners (a portion without a divided weight is shown in white). 6C, 6D, and 6E are examples in which three types of divided weights 110a to 110c are arranged so as to conform to the outer shape of the small work W.

Next, FIG. 7 is a side view for explaining the divided weight setup operation (operation for arranging a number of divided weights at predetermined positions in accordance with the workpiece W) in the present embodiment.
In FIG. 7, reference numeral 201 denotes a set-up carriage, and a weight placing flat plate 202 having the same size as the work W is placed on the upper surface thereof. With reference to a bird's-eye view for arranging the divided weights, the holding rod 109 is passed through any one of the divided weights 110a to 110d (here, the divided weight 110d is added as being heavier than the divided weight 110a). A large number of the weight units 117 are configured, and the large number of weight units 117 are arranged on the upper surface of the weight mounting flat plate 202. The divided weights 110a to 110d can be replaced (rearranged), that is, the load distribution can be changed by changing the number of unit weights inserted into the holding rod 109, for example.

Thereafter, the weight transfer holding portion 118 including the suspension plate 106, the retaining plate 108, the positioning member 107, and the transfer holding rod 114 is lowered from above the many weight units 117, and the positioning member 107 is moved to the setup carriage 201 side. The upper end convex portion of the holding rod 109 is passed through the through hole 108a of the retaining plate 108 through the through hole 108a of the retaining plate 108, and the retaining plate 108 is further slid. The weight transfer holding unit 118 and a large number of weight units 117 are integrated.
As described above, the weight transfer holding unit 118 and a number of weight units 117 are integrated in advance on the set-up carriage 201, and thereafter, the entire set-up carriage 201 is moved directly below the weight transfer device 301 described later. Then, the process moves to the process of transferring the weight unit 117 onto the workpiece W.

Next, with reference to FIG. 8, an operation of transferring a number of weight units 117 held by the weight transfer holding unit 118 and transferring them onto the workpiece W will be described.
FIG. 8A is a plan view of the entire single-side polishing apparatus including the setup carriage 201, and FIG. 8B is a side view of the same.

  In FIG. 8B, the weight transfer device 301 includes an elevating mechanism 304 that raises and lowers the transfer gripping portion 303, and the transfer gripping portion 303 can hold the upper end portion of the transfer holding rod 114. Further, the elevating mechanism 304 and the conveyance gripping portion 303 can rotate between the upper side of the setup carriage 201 and the upper side of the surface plate 104 about the conveyance rotary shaft 302.

  On the set-up carriage 201, the upper end of the transport holding rod 114 of the weight transport holder 118 is gripped by the transport grip 303, and the lifting mechanism 304 is driven to raise in the direction of the arrow c, and then the transport rotation. The shaft 302 is rotated as shown by a one-dot chain line in FIG. Then, the weight transfer holder 118 is transferred to the upper side of the workpiece W, and then the elevating mechanism 304 is driven and lowered, and the positioning member 107 is positioned on the workpiece holder 105, whereby a large number of weight units 117 are moved. It can be placed on the top surface of W. The workpiece W is stored in advance in the window portion of the workpiece holder 105 on the surface plate 104.

After that, if the gripping part 303 for transport releases the gripping of the transporting holding rod 114 and retracts the weight transporting device 301 to relatively rotate and swing the surface plate 104 and the work holder 105, a large number of weights can be obtained. It is possible to perform polishing by pressing the lower surface of the workpiece W given a predetermined load distribution by the unit 117 against the polishing pad 104a.
If the weight transfer holder 118 is disposed above the work holder 105 as shown in FIG. 8B even during polishing of the work W, it is possible to prevent the weight unit 117 from being displaced due to vibration. Since the weight transfer holder 118 is supported by the work holder 105 via the positioning member 107, there is no possibility that the weight of the weight transfer holder 118 is applied to the workpiece W.

As described above, according to this embodiment, the divided weights 110a to 110d are attached to the holding rod 109 on the set-up carriage 201 to form a large number of weight units 117. A load distribution larger than the vicinity of the four corners can be obtained, and the weight transfer holding unit 118, the transfer gripping unit 303, and the like are operated to transfer a large number of weight units 117 onto the workpiece W in a lump. If the conveying grip 303 is retracted, the polishing process can be started immediately.
In addition, in order to smoothly perform polishing under different load distribution conditions, weights having different load distributions are arranged in advance on a plurality of setup carriages 201, and the necessary setup carriage 201 is placed directly below the weight transfer device 301. If it is moved up and down in the direction of the arrow d in FIG. 8B and the entire set-up carriage 201 can be exchanged, the set-up change can be performed in a short time.
As described above, in the present invention, it is possible to prevent the vicinity of the four corners of the rectangular workpiece W from being excessively polished and to polish the entire workpiece W to a substantially uniform thickness. . Further, since a large number of divided weights 110a to 110d and base weight 110x are used, the heat dissipation efficiency is good, and there is no possibility that the workpiece W or the surface plate 104 is deformed by polishing heat.
Furthermore, after the polishing is completed, if the numerous weight units 117 are removed from the workpiece W at once, the polished workpiece W can be carried out, and continuous polishing of the numerous workpieces W is easy.

101: Housing 102: Drive motor 103: Rotating shaft 104: Surface plate 104a: Polishing pad 105: Work holder 105a: Positioning recess 106: Hanging plate 107: Positioning member
107a: posture adjusting unit 108: retaining plate 108a: locking hole 109: holding rods 110, 110a, 110b, 110c, 110d: divided weight 110x: base weight 111: work holder swing frame
112: Hanging piece 113: Buffer material 114: Transfer holding rod 115: Work holder driving motor 117: Weight unit 118: Weight transfer holding unit 201: Set-up carriage 202: Weight mounting plate 203: Positioning receiving unit 301: Weight transfer device 302: Transfer rotating shaft 303: Transfer gripping part 304: Lifting mechanism W: Workpiece

Claims (5)

The work in the work holder placed on the surface plate via the polishing pad is pressurized with a plurality of weights, and the surface plate and the work are rotated relatively to polish one surface of the work with the polishing pad. A single-side polishing apparatus that
As the weight, a plurality of divided weights having different weights are prepared,
The one side, wherein the plurality of divided weights arranged in advance according to a predetermined load distribution outside the surface plate can be collectively transferred to the upper surface of the work in the work holder by a weight conveying device. Polishing equipment. In the single-side polishing apparatus according to claim 1,
The upper ends of the holding rods that respectively hold the divided weights are supported by a retaining plate that penetrates a suspension plate, and the weight transfer device integrally grips the suspension plate and the retaining plate and performs the division. A single-side polishing apparatus, wherein a weight is transferred to the upper surface of the workpiece. In the single-side polishing apparatus according to claim 2,
By sliding the retaining plate relative to the suspension plate, the upper end portion of the holding rod penetrating the suspension plate can be latched in the retaining hole of the retaining plate. A single-side polishing apparatus characterized. In the single-side polishing apparatus according to any one of claims 2 and 3,
Positioning members are disposed at both ends of the suspension plate, and the divided weights are placed on the upper surface of the workpiece while the suspension plate and the retaining plate are positioned on the workpiece holder by the positioning members. A single-side polishing apparatus characterized by the above. In the single-side polishing apparatus according to claim 4,
A single-side polishing apparatus, wherein the workpiece is polished in a state where the retaining plate and the suspension plate are positioned on the workpiece holder by the positioning member.

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