JP2023083325A - Flattening device - Google Patents

Abstract

To provide a flattening device which enables grinding stones to be easily and safely attached to a spindle.SOLUTION: A flattening device 1 includes: a suction holding mechanism which is provided at a spindle flange 26 connected to a spindle 23 and generates a negative pressure between itself and an annular grinding wheel 21a holding grinding stones 21 to suction and hold the grinding wheel 21a on the spindle flange 26; and a friction holding mechanism which moves a pressing wheel 61, which is provided at a lower end of the spindle flange 26, downward in a vertical direction V by biasing means 63 to expand a diameter of a collet 62 externally inserted to the pressing wheel 61 in a radial direction R of the spindle 23 and thereby holds the grinding wheel 21a with the collet 62 even when the suction holding mechanism is stopped and holding of the grinding wheel 21a by the suction holding mechanism is released.SELECTED DRAWING: Figure 10

Description

The present invention relates to a surface processing apparatus for processing a wafer with a grindstone.

BACKGROUND ART In the field of semiconductor manufacturing, back surface grinding is performed to grind the back surface of a semiconductor wafer such as a silicon wafer (hereinafter referred to as “wafer”) in order to form a thin film.

Patent Document 1 discloses a grinding device 1 in which a cup-shaped grindstone 56 is attached to the tip of a spindle 94 . The cup-shaped grindstone 56 is fastened to the spindle 94 with a bolt (not shown) and is detachably attached to the spindle 94 . In addition, the code|symbol is a code|symbol in patent document 1. FIG.

JP-A-11-309673

However, in the grinding apparatus 1 described in Patent Document 1, the cup-shaped grindstone 56 is attached to the spindle 94 by manually tightening about 10 bolts by an operator, so the attachment work of the cup-shaped grindstone 56 is complicated. tended to be In addition, there is a problem that the cup-shaped grindstone 56 may be damaged by accidentally dropping the cup-shaped grindstone 56 during the mounting work.

Therefore, there arises a technical problem to be solved in order to safely and simply attach the grinding wheel to the spindle, and an object of the present invention is to solve this problem.

To achieve the above object, a surface processing apparatus according to the present invention is a surface processing apparatus for processing a wafer with a grindstone attached to a spindle, wherein a spindle flange connected to the spindle is provided with the grindstone. A suction holding mechanism for attracting and holding the grinding wheel to the spindle flange by generating a negative pressure between the held annular grinding wheel and a presser wheel provided at the lower end of the spindle flange in a vertical direction by means of biasing means. to expand the diameter of the collet externally inserted on the presser wheel in the radial direction of the spindle flange, thereby stopping the suction holding mechanism and releasing the holding of the grinding wheel by the suction holding mechanism and a friction holding mechanism capable of holding the grinding wheel.

According to this configuration, the grindstone wheel is held by suction on the spindle flange, and the collet, which expands in diameter as the presser wheel moves in the vertical direction, grips and holds the grindstone wheel. The grindstone can be safely and conveniently attached to the spindle without the need to.

According to the present invention, the grindstone wheel is held by suction on the spindle flange, and the collet, which expands in diameter as the presser wheel moves, grasps and holds the grindstone wheel. It can be safely and conveniently attached to the spindle.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows the surface processing apparatus which concerns on one Embodiment of this invention. FIG. 2 is a side view of the main unit shown in FIG. 1; The perspective view which shows a spindle flange and a grindstone. FIG. 4 is a perspective view of the spindle flange and grindstone shown in FIG. 3 as viewed from below; The perspective view which shows the state which removed the grindstone from the spindle flange. FIG. 4 is a perspective view showing a state in which a collet is attached to the presser wheel; Cross-sectional view of the tip of the spindle. FIG. 7 is a cross-sectional view along the line AA of FIG. 7; FIG. 8 is a cross-sectional view along the line BB of FIG. 7; FIG. 10 is an enlarged view showing a main part of FIG. 9;

An embodiment of the present invention will be described based on the drawings. In addition, hereinafter, when referring to the number, numerical value, amount, range, etc. of the constituent elements, unless otherwise specified or clearly limited to a specific number in principle, it is limited to the specific number It does not matter if it is more than or less than a certain number.

In addition, when referring to the shape and positional relationship of components, etc., unless otherwise specified or in principle clearly considered otherwise, etc. include.

In addition, the drawings may exaggerate characteristic parts by enlarging them in order to make the characteristics easier to understand. In addition, in cross-sectional views, hatching of some components may be omitted in order to facilitate understanding of the cross-sectional structure of the components.

FIG. 1 is a perspective view showing the basic configuration of the surface processing apparatus 1 with the spindle feed mechanism 25 and the transfer unit 3 omitted. FIG. 2 is a longitudinal sectional view showing the internal structure of the main unit 2 and the transport unit 3 shown in FIG.

The planarization apparatus 1 grinds the back surface of the wafer W. Specifically, the back surface of a substrate made of a difficult-to-cut material such as sapphire or silicon carbide (the surface opposite to the surface on which devices are formed) is ground. Grinding. However, the object to be processed by the surface processing apparatus 1 is not limited to these.

The surface processing apparatus 1 includes a main unit 2 having a grindstone 21 and a transport unit 3 arranged below the main unit 2 .

The main unit 2 includes an arch-shaped column 22, a spindle 23 to which a grindstone 21 is attached, three linear guides 24 that slidably support the spindle 23 in the vertical direction V, and the spindle 23 that moves up and down in the vertical direction V. and a spindle feed mechanism 25 that allows

The spindle 23 is housed in a groove 22b recessed in the vertical direction V in the front surface 22a of the column 22. As shown in FIG. The spindle 23 is configured such that the grindstone 21 is attached via a spindle flange 26 connected to the lower end thereof, and the grindstone 21 can be rotated by a motor (not shown). Detailed configurations of the grindstone 21 and the spindle flange 26 will be described later.

The linear guides 24 are composed of two front linear guides 24a arranged in front of the column 22 and one rear linear guide 24b arranged in the groove 22b.

A front linear guide 24a is located at the edge of groove 22b and is mounted to support the front end of saddle 23a. A rear linear guide 24b is located at the bottom of the groove 22b and is mounted to support the rear center of the saddle 23a.

The front linear guide 24a and the rear linear guide 24b are provided parallel to each other along the vertical direction V. As shown in FIG. Thus, the front linear guide 24a and the rear linear guide 24b function as guide rails for the saddle 23a.

The spindle feed mechanism 25 includes a slider 25a connected to the saddle 23a, a ball screw 25b that raises and lowers the slider 25a, and a motor 25c that rotates the ball screw 25b. The ball screw 25b rotates forward by driving the motor 25c, and the slider 25a descends in the vertical direction V, thereby lowering the saddle 23a.

The main unit 2 is provided with an in-process gauge (not shown) for measuring the thickness of the wafer W. As shown in FIG. When the thickness of the wafer W measured by the in-process gauge reaches a desired value, the motor 25c is driven to rotate the ball screw 25b in the reverse direction, and the saddle 23a connected to the slider 25a is lifted. are separated from each other.

The transfer unit 3 includes a chuck 31 capable of holding the wafer W by suction, a slider 32 on which the chuck 31 is placed, and a slider drive mechanism 33 that drives the slider 32 .

The chuck 31 is connected to a negative pressure source (not shown) and can hold the wafer W on the chuck 31 by suction. Further, the chuck 31 is rotatable about a vertical axis passing through the center of the chuck 31 by a motor 31a.

The slider 32 is slidable on the rail 32a, so that the chuck 31 and the slider 32 slide together.

The slider driving mechanism 33 slides the slider 32 by a motor 33b via a belt/pulley mechanism 33a.

Operations of the surface processing apparatus 1 are controlled by a control unit 4 . The control unit 4 controls each component constituting the surface processing apparatus 1 . The control unit 4 is composed of, for example, a CPU, a memory, and the like. The functions of the control unit 4 may be realized by controlling using software, or may be realized by operating using hardware.

With such a configuration, the surface processing apparatus 1 grinds the wafer W according to the following procedure. First, the wafer W is held by the chuck 31 by suction. Next, after the wafer W is loaded below the grindstone 21 by the slider 32, the motor 25c is driven to rotate the ball screw 25b forward, and the saddle 23a connected to the slider 25a is lowered to move the grindstone 21 to the wafer W. approach to the vicinity of Then, the wafer W is ground by pressing the grindstone 21 against the rear surface of the wafer W while rotating the grindstone 21 and the chuck 31 .

After that, when the wafer W is ground to a desired thickness, the rotation of the grindstone 21 and the chuck 31 is stopped, the motor 25c is driven to reversely rotate the ball screw 25b, and the saddle 23a connected to the slider 25a is raised. , the grindstone 21 is separated from the wafer W. Next, the slider 32 unloads the wafer W to the rear of the main unit 2 . Then, the suction holding of the wafer W by the chuck 31 is released, and the grinding of the wafer W by the surface processing apparatus 1 is finished.

Next, a mechanism for attaching the grindstone 21 to the spindle flange 26 will be described in detail with reference to FIGS. 3-9.

A plurality of grindstones 21 are installed along the circumferential direction of the grindstone wheel 21a at the lower end of the annular grindstone wheel 21a. The grindstone wheel 21a has a five-shaped cross section and includes a substantially vertical inner peripheral surface 21b and a substantially flat upper surface 21c.

The spindle flange 26 is attached to the lower end of the spindle 23 with bolts (not shown). The spindle flange 26 includes a base portion 26a having an H-shaped cross section and an outer peripheral ring portion 26b erected downward in the vertical direction V from the peripheral edge of the base portion 26a. The spindle flange 26 is provided with an adsorption holding mechanism and a friction holding mechanism.

The suction holding mechanism is attached to a negative pressure source 52 connected via a pipe line 51a to a suction groove 51 formed on the lower surface of the outer peripheral ring portion 26b, and to a seal groove 53 formed on the lower surface of the spindle flange 26. an O-ring 54; The suction groove 51 and the seal groove 53 are formed on the lower surface of the outer peripheral ring 26b over the circumferential direction C on concentric circles around the rotating shaft of the spindle 23. As shown in FIG. The suction groove 51 is formed between two seal grooves 53 .

An O-ring 54 seals between the lower surface of the outer peripheral ring portion 26b and the upper surface 21c of the grinding wheel 21a, and the negative pressure source 52 applies a negative pressure between the lower surface of the outer peripheral ring portion 26b and the upper surface 21c of the grinding wheel 21a. The grindstone wheel 21a is held by the spindle flange 26 by suction.

A detection means (not shown) for detecting that the grinding wheel 21a is not held by suction on the spindle flange 26 may be provided. The detection means is, for example, a pressure sensor or the like that monitors the pressure in the pipeline 51a. If such a pressure sensor is used, for example, when the grinding wheel 21a is attached obliquely to the spindle flange 26 or the like, and there is no pressure drop in the pipe line 51a due to an improper attachment, the grinding wheel 21a can be It is possible to grasp in advance that the spindle flange 26 is not held by suction before starting processing.

The friction retention mechanism includes a presser wheel 61 provided at the lower end of the spindle flange 26 and a collet 62 externally fitted on the presser wheel 61 .

The presser wheel 61 is formed to have a diameter smaller than that of the outer ring portion 26b and is accommodated within the base portion 26a. A pressing surface 61a is formed on the lower outer peripheral edge of the pressing wheel 61 so that the pressing surface 61a is slanted so that the diameter of the pressing surface 61a gradually decreases in the vertical direction V from the top to the bottom.

A biasing means 63 and a cylinder 64 are provided between the spindle flange 26 and the presser wheel 61 .

The biasing means 63 is, for example, a coil spring, and is provided to bias the presser wheel 61 away from the spindle flange 26, that is, downward in the vertical direction V. As shown in FIG.

The cylinder 64 is configured to be movable upward in the direction in which the pressing wheel 61 approaches the spindle flange 26, that is, in the vertical direction V, and is an air cylinder, for example. Although the driving method of the cylinder 64 is pneumatic, it is not limited to this.

A bearing 65 is preferably provided between the spindle flange 26 and the presser wheel 61 . The bearing 65 is, for example, a direct-acting ball bearing, and guides the presser wheel 61 to move in the vertical direction V relative to the spindle flange 26 .

As shown in FIG. 7, the biasing means 63, the cylinder 64 and the bearing 65 are provided along the circumferential direction C of the presser wheel 61 when viewed from above. Specifically, six cylinders 64 are arranged at equal intervals, and one biasing means 63 or one bearing 65 is provided between two adjacent cylinders 64 .

Also, the three biasing means 63 are arranged at the vertices of an equilateral triangle when viewed from the top, and the three bearings 65 are arranged at the vertices of the equilateral triangle when viewed from the top, so that the presser wheel 61 remains horizontal. It can move in the vertical direction V.

In the above-described configuration, the biasing means 63 and the single-acting cylinder 64 cooperate to move the presser wheel 61 up and down along the vertical direction V. When 64 moves the presser wheel 61 up and down in the vertical direction V, the biasing means 63 may be omitted.

The collet 62 is fitted onto the presser wheel 61 . The collet 62 is made of metal and has an annular shape. The collet 62 includes a substantially circular slit window 62b formed in the peripheral surface 62a in the circumferential direction C, a substantially vertical slit 62d connecting the slit window 62b and the lower end surface 62c of the collet 62, It has Thereby, the rigidity of the collet 62 is reduced from the lower end surface 62c to the slit window 62b.

A base portion 62e of the collet 62 is fastened to the outer peripheral ring portion 26b with a bolt 66, and the spindle flange 26 and the collet 62 are integrated.

Below the collet 62, there is formed a tapered portion 62f which is formed thick so as to gradually decrease in diameter from the top to the bottom in the vertical direction V. As shown in FIG.

Next, the operation of the adsorption holding mechanism and the friction holding mechanism will be described with reference to the drawings.

When attaching the grindstone wheel 21a to the spindle flange 26, first, the grindstone wheel 21a is placed at a predetermined position. Specifically, the grindstone wheel 21a is arranged so that the outer peripheral ring portion 26b and the grindstone wheel 21a are in close contact with each other.

Next, the negative pressure source 52 is activated, and the grinding wheel 21a is held by the spindle flange 26 by suction.

The cylinder 64 is stopped while the grindstone wheel 21 a is held by the spindle flange 26 , and the presser wheel 61 is moved downward in the vertical direction V by the biasing force of the biasing means 63 .

That is, as shown in FIG. 10, as the presser wheel 61 moves, the tapered portion 62f of the collet 62 is expanded in the radial direction R by the presser surface 61a so that the collet 62 grips and holds the grindstone wheel 21a. . Further, since the collet 62 grips the grindstone wheel 21a over the entire outer peripheral surface, the gripping force of the collet 62 is dispersed and the grindstone wheel 21a can be firmly held without being damaged.

Further, the biasing means 63 moves the presser wheel 61 downward in the vertical direction V, so that even if the power supply to the surface processing apparatus 1 is stopped, the biasing means 63 keeps the grindstone wheel 21a from moving. Since the force is continuously applied downward in the vertical direction V, the grindstone 21 can be prevented from falling.

Next, when removing the grindstone wheel 21 a from the spindle flange 26 , the cylinder 64 is driven to move the pressing wheel 61 upward in the vertical direction V against the biasing force of the biasing means 63 . Accordingly, as the presser wheel 61 moves, the diameter of the tapered portion 62f of the collet 62 is reduced, and the grasping force with which the collet 62 grasps the grindstone wheel 21a decreases.

After the collet 62 is separated from the grindstone wheel 21a, the negative pressure source 52 is stopped, and the grindstone wheel 21a and the spindle flange 26 are released from the chucking and holding, whereby the grindstone wheel 21a can be removed from the spindle flange 26. .

It should be noted that the present invention can be modified in various ways without departing from the spirit of the present invention, and it is a matter of course that the present invention extends to the modified ones.

REFERENCE SIGNS LIST 1: plane processing device 2: main unit 3: transport unit 4: control unit 21: grindstone 21a: grindstone wheel 21b: inclined surface 21c: inner peripheral surface 21d ... Flat surface 22 ... Column 23 ... Spindle 24 ... Linear guide 25 ... Spindle feed mechanism 26 ... Spindle flange 31 ... Chuck 32 ... Slider 33 ... Slider drive Mechanism 51: Adsorption groove 51a: Pipe line 52: Negative pressure source 53: Seal groove 54: O-ring 61: Presser wheel 61a: Presser surface 62: Collet 62b ...Slit window 62c ...Lower end surface 62d ...Slit 62e ...Base portion 62f ...Tapered portion 63 ...Forcing means 64 ...Cylinder 65 ...Bearing 66 ... Bolt W ... Wafer

Claims (1)

A surface processing apparatus for processing a wafer with a grindstone attached to a spindle,
a suction holding mechanism provided on a spindle flange connected to the spindle and generating a negative pressure between the grinding wheel and an annular grinding wheel that holds the grinding wheel to attract and hold the grinding wheel on the spindle flange;
A presser wheel provided at the lower end of the spindle flange is vertically moved downward by an urging means to expand the diameter of the collet externally inserted in the presser wheel in the radial direction of the spindle flange. a friction holding mechanism capable of holding the grinding wheel even when the mechanism stops and the holding of the grinding wheel by the suction holding mechanism is released;
A plane processing device comprising:

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