JP2615377B2 - Slicing machine cutting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting apparatus for a slicing machine, and more particularly to a cutting apparatus for a slicing machine for manufacturing a semiconductor wafer by cutting a semiconductor ingot into thin pieces.

[0002]

2. Description of the Related Art In a slicing machine, an inner peripheral blade or an outer peripheral blade is rotated at a high speed and pressed against a semiconductor ingot to produce a semiconductor wafer. in this case,
In consideration of the yield of the semiconductor wafer and post-processing, it is advantageous to minimize the displacement of the blade during cutting and to reduce the warpage of the wafer.

However, as the diameter of semiconductor wafers increases, the blade diameter also increases, and the cutting position of the blade becomes unstable during cutting, resulting in uneven blade shape, clogging, and surface tension of cutting fluid. The surface of the cut workpiece tends to be warped due to a change in cutting resistance or the like. Under such circumstances, various measures have been conventionally taken to prevent warpage that occurs when the rotating blade is cut.

In Japanese Patent Application Laid-Open No. 61-98513, air nozzles are provided on both sides of a blade surface, and a blade sensor is provided adjacent to the air nozzle. Detects the displacement amount and displacement direction of the blade from the zero position of the blade, air is injected from an air nozzle to correct the displacement so as to eliminate the displacement, and the displacement of the blade is corrected.

In Japanese Patent Application Laid-Open No. 62-225308, cooling / lubricating water supply nozzles are provided on both sides of a blade surface, and a blade sensor is provided in the vicinity of the nozzle. Cooling / lubricating water is sprayed from the nozzle in the same manner as in the control method of Japanese Patent Application Laid-Open No. 61-98513 to correct the displacement of the blade. In Japanese Patent Application Laid-Open No. 1-110105, a negative pressure suction type nozzle is provided on both sides of the blade surface and a blade sensor is provided, and when the displacement of the blade is detected by the blade sensor, the negative pressure suction type on the opposite side of the blade displacement is provided. Air is blown out from the nozzle to generate a negative pressure to correct the displacement of the blade.

In Japanese Utility Model Application Laid-Open No. Sho 61-122811, a semiconductor ingot or a blade is made movable in an axial direction, and a blade sensor for detecting an axial displacement of the blade is provided.
When detecting the displacement of the blade based on the signal from the blade sensor, move the ingot or blade in the axial direction,
Correct the axial displacement of the blade.

[0007]

In the cutting device of the conventional slicing machine, the position of the blade before cutting is set to a zero position, and from this zero position, displacement in the + direction (warpage) or displacement in the-direction (warpage). Is corrected by a nozzle or the like so as to be detected by the blade sensor and returned to the zero position. However, the inner peripheral blade raises its outer peripheral edge to generate tension, and the rigidity of the vicinity of the inner peripheral blade is lower than that of the outer peripheral edge. Therefore, even if cutting is performed in a state of low rigidity, warpage is likely to occur, and since the rigidity is low, the correction of the warp is not sufficiently performed, and the processing accuracy required for the wafer is difficult to obtain.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a cutting apparatus for a slicing machine which has sufficient rigidity in the vicinity of an inner peripheral blade of a blade and can perform machining with high accuracy.

[0009]

In order to achieve the above object, the present invention provides a cutting apparatus for a slicing machine for cutting a crystal ingot into thin flakes with an inner peripheral blade of a donut-shaped rotating blade. Pressurizing means installed near a cutting portion of the blade, for partially applying axial force near the cutting portion of the rotating blade to partially displace the cutting portion of the rotating blade in the axial direction; Installed adjacent to
A blade sensor for detecting the axial displacement of the rotating blade in a non-contact manner, and before cutting the crystal ingot,
By driving the pressurizing means, the position of the cutting portion of the rotating blade is further partially axially displaced from the position at the time of the predetermined rotation before the start of cutting, and the position of the cutting portion of the displaced rotating blade. And a control unit that controls the position of the cutting unit of the rotating blade during cutting with reference to the reference position.

[0010]

According to the present invention, the cutting portion of the rotating blade is previously displaced by applying an axial force to the vicinity of the inner peripheral blade of the rotating blade by the pressurizing means, and the position of the displaced cutting portion of the rotating blade is set as a reference position. Cut the crystal ingot. in this case,
Since the rotating blade is displaced in advance, the rigidity is high, the warpage during cutting is small, and the rigidity of the rotating blade is high, so that the position control of the inner peripheral blade during cutting becomes easy.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a cutting apparatus for a slicing machine according to the present invention will be described below in detail with reference to the accompanying drawings.
In FIG. 1, a chuck body 12 is fixed to an upper end of a spindle 10, and a motor (not shown) is connected to a lower end of the spindle 10 so that the spindle 10 and the chuck body 12 rotate. Has become. An outer peripheral edge of a donut-shaped blade 14 is raised on the chuck body 12, and an inner peripheral blade 16 is formed on an inner peripheral edge of the blade 14. The inner peripheral blade 16 is made of fine diamond abrasive grains or the like. The outer peripheral edge of the blade 14 can be adjusted in tension by a known extension mechanism (not shown) of the chuck body 12.

An upper end of a semiconductor ingot 20 is fixed to a lower surface of the work support base 18. The work support table 18 can be moved in the cutting and feeding direction (XX direction) by the cutting and feeding mechanism 22. Further, the work support table 18 is moved by the work indexing mechanism 24 in the work indexing direction (ZZ direction). ) Can be moved. The cutting and feeding mechanism 22 and the work indexing mechanism 24 are driven by a command signal from a control device 26. Further, a pair of air pads 28 are arranged on the upper surface of the blade 14 as shown in FIG. Further, a pair of non-contact type blade sensors 30, 30 are arranged close to the air pads 28, 28. This air pad 2
As shown in FIG. 2, the blade sensors 30, 30 are arranged on both sides of the ingot 20 being cut, and the air pad 28 and the blade sensor 30 are located near the inner peripheral blade 16 of the blade 14. Are located in Therefore, when air is ejected from the air pads 28, the inner peripheral blade 16 of the blade 14 bends downward as shown in FIG.

The air pads 28 are connected to an air pressure adjusting device 32 shown in FIG.
Is controlled by a command signal from the control device 26. The signals from the blade sensors 30, 30 are transmitted to the control device 26.
The control device 26 can adjust the air pressure adjusting device 32 based on this signal. The cutting of the ingot by the cutting device of the slicing machine according to the present invention configured as described above is performed as follows. First, the blade 14 is stretched with a predetermined tension by a blade stretching mechanism of the chuck body 12. However, since the blade 14 is stretched by applying pressure to the outer peripheral edge of the blade 14, the rigidity near the inner peripheral blade 16 is smaller than that on the outer peripheral side of the blade 14, and the rigidity is sufficient to obtain the necessary precision for the wafer. Is not known empirically. For this reason, in the conventional cutting apparatus, warpage occurs during cutting, and an air nozzle or the like is provided to correct the warpage. However, the position of the inner peripheral blade cannot be sufficiently controlled. In the present invention, air having a predetermined pressure is jetted from the air pads 28 before the blade is cut and before cutting. This causes the blade 14 to bend downward as shown in FIG. In this state, sufficient rigidity is given to the vicinity of the inner peripheral blade 16 of the blade 14,
Cutting is started with the downwardly bent position as a reference position. At this time, the position of the blade 14 is
0 and 30 are detected, and the control device 26 stores them.

In this state, the cutting feed mechanism 22 is operated to move the work support 18 in the direction of the inner peripheral blade 16. When cutting is performed in this state, sufficient rigidity is given to the inner peripheral blade 16 so that the cutting position of the blade is stable, and it is possible to reduce displacement of the inner peripheral blade 16 due to surface tension or the like as compared with the related art. it can. That is, in this state, the blade 14 is inclined, and surface tension is hardly generated. When warpage occurs, the position of the inner peripheral blade 16 is detected by the blade sensors 30, 30, and the air pressure adjusting device 32 is controlled so as to return to the stored reference position. This control is also performed accurately because the rigidity of the blade 14 is high.

In the above embodiment, the air pressure emitted from the air pads 28, 28 was adjusted by using the air pressure adjusting device 32. However, the present invention is not limited to this, and the air pressure adjusting device 50 shown in FIG. 5, FIG. 6 or FIG. , 52 or 54 may be used. Hereinafter, based on FIG. 5, FIG. 6 or FIG.
0, 52 or 54 will be described. Note that the same reference numerals are given to the same similar members as those in the above-described embodiment, and the description is omitted.

The beam 56 of the air pressure adjusting device 50 is
8, the cantilever is supported by a slicing machine main body 60 via a beam 8, and a weight 62 is movably provided on the beam 56. A shaft 64 is screwed to the weight 62, and the shaft 64 is coaxially connected to a rotation shaft 66A of the motor 66. The motor 66 is fixed to the right end of the beam 56.
An air pad 28 is provided at the left end of the beam 56. Here, assuming that the weight of the weight 62 is P1 and the weight of the weight 62 acting on the air pad 28 is P2, the relationship of P2 = (L1 / L2) P1 is established between P1 and P2.

When the air pressure adjusting device 50 rotates the motor 66, the weight 62 moves along the beam 56 in the direction of arrows AB. Therefore, when the weight 62 is moved in the direction of the arrow A, L1 increases, so that the value of P2 increases from the relationship of P2 = (L1 / L2) P1, and the beam 56 counterclockwise resists the urging force of the leaf spring 58. Rotate in the direction. As a result, the air pad 28 approaches the blade 14 (that is, the gap between the air pad 28 and the blade 14 becomes smaller), so that the pressure of the air jetted from the air pad 28 to the blade 14 increases, and the blade 14 bends further downward. Sufficient rigidity is provided.

When the weight 62 is moved in the direction of arrow B, L
Since 1 becomes smaller, the value of P2 becomes smaller, and the gap between the air pad 28 and the blade 14 becomes larger. Therefore, the pressure of the air jetted from the air pad 28 to the blade 14 decreases. Thus, the air pressure adjusting device 50 can adjust the rigidity of the blade 14 by moving the weight 62.
In FIG. 5, reference numeral 68 denotes a bearing that rotatably supports the shaft 64.

The air pressure adjusting device 52 shown in FIG. 6 has an air pressure control in that a beam 56 is cantilevered by a slicing machine body 60 via a leaf spring 58 and a weight 62 is movably provided on the beam 56. It is the same as the adjusting device 50. The air pressure adjusting device 52 differs from the air pressure adjusting device 50 in that the weight 62 moves on the belt 70. That is, the endless belt 70 is connected to the weight 62, and the belt 70 is connected to the pulleys 70 and 7.
2 is stretched. The pulleys 72 and 74 are rotatably supported by the beam 56 at predetermined intervals, and a motor 76 is connected to the pulley 74 so as to be able to transmit a rotational force. Therefore, when the motor 76 is driven, the weight 62 is
6 along arrow AB. Therefore, the air pressure adjusting device 52 can adjust the rigidity of the blade 14 by moving the weight 62 similarly to the air pressure adjusting device 50.

The beam 8 of the air pressure adjusting device 54 shown in FIG.
Reference numeral 0 denotes a slicing machine main body 60 at the right end that is cantilevered, and an air pad moving mechanism (for example, a piezoelectric element) 82 at the left end. An air pad 28 is provided on the piezoelectric element 82. Therefore, when a voltage is applied to the piezoelectric element 82, the piezoelectric element operates and the air pad 28 moves in the vertical direction. Thus, the air pressure adjusting device 54 can adjust the air pressure of the blade 14 by moving the air pad 28 similarly to the air pressure adjusting devices 50 and 52, and can adjust the rigidity of the blade 14.

As shown in FIG. 4, only one air pad 28 may be provided, and the blade may be cut obliquely. In the above embodiment, the air pad 28 is provided on only one side of the blade 14, but may be provided on both side surfaces. In the above embodiment, the blade is bent by the air pressure. However, the blade may be bent by the fluid pressure, or another axial pressing means may be used.

In the above embodiment, the air pressure adjusting device 32 is controlled to return the blade 14 to the reference position. However, the present invention is not limited to this. The wafer shape curve) may be input to the control device 26, and the cutting may be performed by controlling the air pressure adjusting device 32 along the cutting curve. Also in this case, the blade 14 has a higher rigidity than the conventional one, so that a wafer having a shape closer to an ideal cutting curve is cut.

[0023]

As described above, according to the cutting apparatus for a slicing machine according to the present invention, the cutting portion of the inner peripheral blade is preliminarily displaced to increase rigidity, and the cutting position of the displaced rotating blade is used as a reference position. To cut the wafer. Therefore, the cutting can be performed with a higher rigidity of the inner peripheral blade as compared with the conventional cutting device, so that highly accurate processing can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic view of a cutting device of a slicing machine according to the present invention.

FIG. 2 is a plan view showing a main part of the cutting device of the slicing machine according to the present invention when viewed from a plane;

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a sectional view taken along line AA in FIG. 2 when there is one air pad;

FIG. 5 is a side view showing another embodiment of the air pressure adjusting device used in the cutting device of the slicing machine according to the present invention.

FIG. 6 is a side view showing a modification of FIG. 5;

FIG. 7 is a side view showing another modification of FIG. 5;

[Explanation of symbols]

 14 ... blade 16 ... inner peripheral blade 20 ... ingot 26 ... control device 28 ... air pad 30 ... blade sensor

Claims (5)

(57) [Claims] 1. A cutting device for a slicing machine for cutting a crystal ingot into flakes with an inner peripheral blade of a donut-shaped rotating blade, wherein the rotating blade is installed near a cutting portion of the rotating blade.
A partial axial force is applied near the cut part of the blade to
Pressurizing means for partially displacing the cut part of the blade in the axial direction
And installed adjacent to the pressurizing means, the rotating blade
A blade sensor for detecting an axial displacement amount in a non-contact manner, and driving the pressing means before cutting the crystal ingot.
To move the cutting part of the rotating blade to the position before the start of cutting.
Displaced further in the axial direction than the position at the time of constant rotation
And the position of the cut part of the displaced rotating blade
As the reference position, the cutting part of the rotating blade during cutting
Cutting device slicing machine for a control unit for controlling the position, comprising the. 2. The pressurizing means is an air pad.
Rotational shake caused by the pressure of air blown out of the pad
The cutting device for a slicing machine according to claim 1, wherein the cutting portion of the blade is displaced in the axial direction . 3. The pressure of air blown from the air pad.
Air pressure adjusting means for adjusting the force is provided.
The cutting device for a slicing machine according to claim 2. 4. The air pad is a slicing machine.
At the tip of a cantilever supported by a body via a leaf spring
The gap between the air pad and the rotary blade is
Moving a freely movable weight along the beam
3. The slide according to claim 2, wherein
Ising machine cutting equipment. 5. The air pad is a slicing machine.
Air pad advance / retreat movement mechanism at the tip of the cantilever supported by the body
The air pad advance / retreat moving mechanism is provided through
Moving the air pad forward and backward with respect to the rotating blade
Can adjust the gap between the air pad and the rotating blade
3. The slicing machine according to claim 2, wherein:
Cutting equipment.