JP3559430B2 - Slurry supply structure of wire saw - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention belongs to the technical field of a wire saw for cutting into thin slices (wafers) by supplying a slurry containing abrasive grains to a wire running on a work of a hard and brittle material such as a semiconductor material and a magnetic material.
[0002]
[Prior art]
FIG. 4 shows a side view of a conventional wire saw including a work processing unit 10 and a control unit 20 for controlling the traveling of the wire and the entire apparatus, without a cover.
A work processing portion 10 is provided on one side of the column 30 erected on the base 50 of the wire saw.
The workpiece processing portion 10 of the wire saw includes a wire row 16 formed by winding one wire 14 between, for example, three processing rollers 12, 12, 12 arranged so as to be parallel to each other. And a slurry supply nozzle 18 for supplying a slurry containing abrasive grains to the wire row 16.
[0003]
FIG. 5 is an axial sectional view of the slurry supply nozzle 18, and FIG. 6 is a sectional view taken along line 6-6 of FIG.
The slurry supply nozzle 18 is a cylindrical nozzle having an inner supply pipe 182 disposed inside so as to be concentric with the outer supply pipe 180 and having one end closed, and a slurry supply pump (not shown) at the other end. It is connected to supply slurry inside the inner supply pipe 182.
As shown in FIG. 6, the outer supply pipe 180 has a slit 183 formed in the lower surface in the longitudinal direction of the pipe, and the inner supply pipe 182 has a plurality of slurry supply holes 181 formed in the upper surface in the longitudinal direction of the pipe. . Therefore, the slurry is uniformly discharged from the slurry supply hole 181 in the longitudinal direction of the inner supply pipe 182, and is filled in the outer supply pipe 180. Therefore, the slurry can be uniformly supplied to the wire row 16 in a state where the slurry is rectified from the slit 183.
[0004]
The grain size of the abrasive grains contained in the slurry is usually on the order of several tens of microns, and the slurry adheres to the wire surface together with the abrasive grains due to the viscosity of the slurry, and is brought into the cut surface of the work W by the traveling of the wire array 16. It is.
[0005]
The wire row 16 is configured such that one wire 14 wound around a pair of reels 22 provided on the left and right side rear sides with the column 30 erected on the base 50 interposed between the outer periphery of each of the rollers 12, 12. It is guided by an annular groove formed at a predetermined pitch on the surface and wound around each of the rollers 12, 12, 12, so that when the wire 14 is wound on one of the reels 22, the wire row 16 Travels at a predetermined speed according to the winding direction of the reel 22.
The traveling speed and traveling direction of the wire array 16 are determined by a reel rotation motor that rotates the reel 22, and these control programs are preset in the control unit 20.
Further, the wire 14 unwound from the reel 22 on the base 50 is traversed up and down by a traverse mechanism and guided, and a predetermined tension is applied by a tension applying mechanism. Therefore, a predetermined tension is always applied to the wire row 16 formed between the rollers 12, 12, 12.
[0006]
A work W made of a hard and brittle material is supported by the work support mechanism 40 above and below the wire row 16 of the work processing section 10 so as to be able to move up and down with respect to the wire row 16. The work W held by the work support mechanism 40 descends and is pressed against and contacts the traveling wire row 16. At this time, an aqueous or oily slurry containing free abrasive grains is supplied from the slurry supply nozzle 18 onto the wire row 16, and the free abrasive grains in the slurry brought into the cut surface of the work W and the lapping due to the travel of the wire row 16. By the action, the work W is cut into a wafer shape.
[0007]
By reversing the rotation direction of the reel 22 by the reel rotation motor, the wire row 16 of the work processing unit can be converted into the arrow F direction and the arrow R direction in FIG. 4 at any time.
An arrow F in FIG. 4 indicates a new wire supply direction in which a new wire 14 that has not yet been cut into the work W enters, and an arrow R indicates the wire 14 that has been cut once returned to the inside of the work W. Thus, the returning directions in which the workpiece W is cut again are shown.
This wire saw alternately repeats a forward / reverse traveling operation of, for example, traveling 10 m in the F direction in FIG. 4 and returning 9 m in the R direction, for example, so as to travel overall in the F direction which is the new line supply direction. ing.
4 is a new line entrance side where a new line of the wire 14 is supplied to the work W, B is a new line exit side where a new line of the wire 14 exits from the work W, Shown respectively.
[0008]
[Problems to be solved by the invention]
However, since the cutting of the work W is performed while the wire row 16 always reciprocates and runs as a whole in the new line supply direction, the work cutting surface is closer to the new line entrance side than to the new line exit side. Therefore, more slurry will be brought.
As the wire row 16 travels, loose abrasive grains contained in the slurry are brought into the cut surface of the work W, and the work of cutting the work W is performed. Therefore, if the amount of the introduced abrasive grains is different, the cutting state is also different. In this case, more wire, that is, slurry is supplied on the new line entrance side of the work W than on the exit side, and cutting proceeds more efficiently than on the new line exit side. As a result, the slices (wafers) on the entrance side tend to be thinner as shown in the cross-sectional view of the slices (wafers) in FIG. 7, and after cutting, one slice (wafer) has an entrance side and an exit side. There is a problem that the thickness is different on the side.
[0009]
[Means for Solving the Problems]
The present invention provides a wire array formed by wires wound at a predetermined pitch between a plurality of processing rollers in a new wire supply direction in which a new wire enters a work and a return direction opposite thereto. The wire reciprocating operation is alternately repeated, so that the wire is reciprocated as a whole in a new line supply direction, a slurry containing abrasive grains is supplied on the wire, and a workpiece is pressed against the wire row to be cut. In the wire saw performing the processing, the supply slurry amount of the slurry supply nozzle arranged on the new line exit side of the wire with respect to the work is larger than the supply slurry amount of the slurry supply nozzle arranged on the new line entrance side of the wire. The above problem has been solved by a wire saw slurry supply structure characterized by the following.
[0010]
According to an embodiment of the present invention, the number of the slurry supply nozzles on the new line outlet side is greater than the number of the slurry supply nozzles on the new line inlet side. The slit width of the slurry supply nozzle arranged on the line exit side is made larger than the slit width of the slurry supply nozzle arranged on the new line entrance side, and the slurry supply nozzle is arranged on the new line exit side as in claim 4. Supply more slurry to the former by adjusting the amount of slurry supplied from the supply pump via the throttle valve to the slurry supply nozzle and the slurry supply nozzle located on the new line inlet side, respectively. And so on.
[0011]
[Action]
According to the present invention, more slurry can be supplied to the new line exit side of the work cutting surface, so that substantially the same amount of abrasive grains is brought into the work cutting surface as a whole, and The cutting process proceeds in substantially the same manner on the line entrance side and the exit side.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the slurry supply structure for a wire saw according to the present invention will be described with reference to FIGS. 1 to 3.
Note that the method of traveling the wires, the control unit for controlling the entire apparatus, and the like are the same as those of the conventional apparatus shown in FIG.
Further, the new line supply direction and the return direction of the wire array 16 and the entrance side and the exit side of the new line with respect to the work W have the same positional relationship as in FIG.
[0013]
FIG. 1 is a longitudinal sectional view of an essential part for explaining the operation of the first embodiment 101 of the slurry supply structure for a wire saw of the present invention.
The slurry supply structure 101 of the wire saw has a configuration in which the number of slurry supply nozzles 18 on the new line outlet side is greater than the number of slurry supply nozzles 18 on the new line inlet side (that is, three and two). .
[0014]
In FIG. 1, since the amount of slurry supplied to each slurry supply nozzle 18 is equal, a relatively large amount of slurry is supplied to the wire row 16B on the B side, so that the wire row 16 travels in the direction R in FIG. Then, when the wire row 16B on the B side passes below the slurry supply nozzle 18, more slurry adheres to the wire row 16B side as compared with the wire row 16A side, and is taken into the workpiece cut surface as it is. .
Accordingly, since the same amount of abrasive grains are brought in on the cut side of the work W and the cut side of the work B are cut, the thickness of the sliced piece (wafer) after cutting is reduced to the new line entrance side and the exit of the new line. Can be almost equal on the side.
[0015]
Next, a second embodiment of the present invention will be described with reference to FIG.
FIG. 2A is a radial cross-sectional view of a slurry supply nozzle 18a disposed on the A side in the workpiece processing section 10 of the wire saw in FIG. 4, and FIG. 2B is a slurry supply nozzle 18b disposed on the B side. 1 shows a radial sectional view of FIG.
Since the slit widths 181b and 183b of the slurry supply nozzle 18b arranged on the B side are formed to be larger than the slit widths 181a and 183a of the slurry supply nozzle 18a arranged on the A side, connection is made to the same slurry supply source. If so, more slurry will be supplied to the B-side wire row 16B.
[0016]
Next, FIG. 3 is a vertical sectional view of an essential part for explaining a third embodiment of the present invention.
In the slurry supply structure 103, throttle valves VA and VB are provided in the middle of the pipes connecting the slurry supply nozzles 18A and 18B arranged on the A side and the B side from one supply pump P, respectively. The amount of slurry supply is adjusted by each of the throttle valves VA and VB so that more slurry is supplied to the nozzle 18B on the B side than the nozzle 18A on the A side.
[0017]
According to the second and third embodiments, the same effects as in the embodiment of FIG. 1 can be obtained. In addition, in order to adjust the slurry supply amounts on the A side and the B side, the above embodiments may be appropriately combined and used.
[0018]
In the above embodiment, the supply slurry amount of the slurry supply nozzle disposed on the new line exit side of the wire is described as being larger than the supply slurry amount of the slurry supply nozzle disposed on the new line entrance side of the wire. This is to make the thickness of the wafer to be cut substantially equal between the new line entrance side and the exit side, so how much difference is made in the slurry supply amount between the new line entrance side and the exit side? Is naturally set to achieve the above object.
[0019]
【The invention's effect】
According to the present invention, more slurry is supplied to the wire surface traveling in the return direction R, and more slurry is brought into the new line exit side B of the work cutting surface, whereby the slurry is supplied to the work cutting surface. The bias in the amount of slurry can be eliminated.
As a result, the cutting state of the work can be made uniform at the entrance and exit sides of the new line, so that the sliced pieces (wafers) after cutting have a uniform thickness, and the thickness accuracy can be reduced without post-processing. There is an effect that a good sliced piece (wafer) can be obtained.
[Brief description of the drawings]
FIG. 1 is a vertical sectional view of an essential part for explaining an operation of a first embodiment of a slurry supply structure for a wire saw of the present invention.
FIG. 2 shows a slurry supply nozzle which is a second embodiment of the slurry supply structure for a wire saw of the present invention, and FIG. 2 (a) is a radial cross-sectional view of the slurry supply nozzle arranged on the A side in FIG. FIG. 2B is a radial cross-sectional view of the slurry supply nozzle arranged on the B side in FIG.
FIG. 3 is a vertical sectional view of a main part for describing a third embodiment of a slurry supply structure for a wire saw of the present invention.
FIG. 4 is a side view of a conventional wire saw without a cover.
FIG. 5 is an axial cross-sectional view of a slurry supply nozzle used in a conventional wire saw slurry supply structure.
FIG. 6 is a sectional view taken along line 6-6 of FIG. 5;
FIG. 7 is a cross-sectional view of a sliced piece (wafer) after cutting in the related art.
[Explanation of symbols]
101, 103: Wire saw slurry supply structure 12: Processing rollers 16, 16A, 16B: Wire rows 18a, 18b, 18A, 18B: Slurry supply nozzle W: Work F: New line supply direction R: Return direction A: New line Inlet side B: New line outlet side VA, VB: Throttle valve P: Supply pump

Claims (4)

A wire array formed by wires wound at a predetermined pitch between a plurality of processing rollers is moved forward and backward in a new wire supply direction in which a new wire enters a work and in a reverse return direction. A wire saw that alternately repeats the traveling operation, reciprocates as a whole so as to travel in a new line supply direction, supplies slurry containing abrasive grains on the wire, and presses a workpiece against the wire row to perform a cutting process. At
The supply slurry amount of the slurry supply nozzle arranged on the new line exit side of the wire with respect to the work is set larger than the supply slurry amount of the slurry supply nozzle arranged on the new line entrance side of the wire. ,
Slurry supply structure for wire saw. 2. The slurry supply structure according to claim 1, wherein the number of the slurry supply nozzles on the new line outlet side is greater than the number of the slurry supply nozzles on the new line entrance side. 3. 2. The slurry supply structure according to claim 1, wherein a slit width of the slurry supply nozzle disposed on the new line exit side is larger than a slit width of the slurry supply nozzle disposed on the new line entrance side. 3. For the slurry supply nozzle disposed on the new line exit side and the slurry supply nozzle disposed on the new line entrance side, the amount of slurry supplied from the supply pump is adjusted via a throttle valve, respectively, The slurry supply structure according to claim 1, wherein more slurry is supplied.

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