JP2023029020A - wire saw - Google Patents

Abstract

To provide a wire saw that is configured so as to make force acting on a work-piece feeding mechanism constant even if cutting resistance at the time of cutting a work-piece varies.SOLUTION: A wire saw 1 comprises: a wire 54 that cuts a work-piece W; a plurality of rollers 52 for processing around which the wire 54 is wound; a work-piece feeding mechanism 7 that feeds the work-piece W in a cutting direction in which the work-piece is cut with respect to the wire 54; and a balancer 8 that holds the work-piece feeding mechanism 7. The balancer 8 applies, to the work-piece feeding mechanism 7, force in a direction in which reaction force generated when the wire 54 cuts the work-piece W, own weight of a movable part of the work-piece feeding mechanism 7 and own weight of the work-piece W are offset.SELECTED DRAWING: Figure 1

Description

The present invention relates to a wire saw provided with a work feeding mechanism.

In general, a wire saw that cuts a work such as a semiconductor material or a magnetic material with a wire cuts the work by cutting and feeding the work with a work feeding device while supplying a working fluid to the wire.

In general, a wire saw work feed mechanism includes a guide rail, a nut member provided on a work feed table, a rod screw that is screwed into the nut member, and a drive motor that rotates the rod screw to move the work feed table up and down. , (see, for example, Patent Document 1).

Since the work to be cut is a thin semiconductor wafer, it is required to be cut with high accuracy. The shape of the semiconductor wafer is determined by the relative displacement between the workpiece and the wire. For this reason, the workpiece feeding mechanism is required to have high precision and high rigidity because the straightness is transferred to the wafer.

Japanese Patent Application Laid-Open No. 9-70823 (see FIGS. 2 and 3)

However, in the wire saw described in Patent Literature 1 and in general wire saws, a reaction force is generated in the work feed mechanism due to cutting resistance during machining, and the machine deforms. The reaction force always changes according to the size of the workpiece, the size of the cross-sectional area, and the change in machinability. For this reason, wire saws are desired to have a work feed mechanism that does not deform due to cutting resistance even when the cutting resistance changes.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a wire saw that can maintain a constant force applied to a work feed mechanism even if the cutting resistance during cutting of the work changes.

In order to solve the above-described problems, a wire saw according to the present invention includes a wire for cutting a work, a plurality of processing rollers around which the wire is wound, and a work to be fed to the wire in a cutting direction for cutting the work. A feed mechanism and a balancer that holds the work feed mechanism are provided, and the balancer is composed of a reaction force generated when the wire is used to cut the work, the dead weight of the movable portion of the work feed mechanism, and the weight of the work. It is characterized in that a force is applied to the work feeding mechanism in a direction that offsets its own weight.

According to the present invention, it is possible to provide a wire saw that can keep the force applied to the work feed mechanism constant even if the cutting resistance during cutting of the work changes.

BRIEF DESCRIPTION OF THE DRAWINGS It is a principal part schematic longitudinal cross-sectional view which shows an example of the wire saw which concerns on embodiment of this invention. FIG. 2 is an enlarged schematic plan view of a main part of the wire saw; FIG. 2 is a schematic vertical cross-sectional view of a main part of a wire saw; It is a principal part schematic longitudinal cross-sectional view which shows the modification of the wire saw which concerns on embodiment of this invention. 5 is an enlarged view of a main portion of FIG. 4; FIG.

A wire saw according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG.
In this embodiment, the direction in which the workpiece feed table 61 of the clamping device 6 shown in FIG. , and the right direction in FIG. 2 is referred to as the right.

First, before describing the wire saw 1, the work W used for the wire saw 1 will be described. Further, as shown in FIG. 3, the main parts of the wire saw 1 are formed substantially symmetrically, so one of them will be explained as appropriate and the explanation of the other will be omitted.

<Work>
As shown in FIG. 1, the work W is made of a hard and brittle material such as a semiconductor material, a magnetic material, or ceramic. The work W is attached to the work holding portion 63 of the clamp device 6 and pressed against the wire 54 of the processing device 5 arranged on the wire saw 1 to be cut by cutting.

<Wire saw>
The wire saw 1 is a cutting device that cuts the work W with a wire 54 of the processing device 5 . As shown in FIG. 1, the wire saw 1 includes a base (not shown), a column 3, a saddle 4, a processing device 5, a clamping device 6, a work feeding mechanism 7, a control valve 90, a controller 10, and a and are mainly provided.

<Base>
A base (not shown) is a base that holds the column 3 and the processing device 5 from below. A base (not shown) is arranged over the entire lower end of the wire saw 1 .

<Column>
The column 3 is a columnar member that stands on a base (not shown) and constitutes the main body of the wire saw 1 . A saddle 4 , a work feeding mechanism 7 and a balancer 8 are provided in the column 3 .

<Saddle>
As shown in FIG. 1, the saddle 4 is a vertical feed base arranged to be vertically movable with respect to the column 3 . A clamping device 6 for clamping the workpiece W is supported on the front surface of the saddle 4 . The saddle 4 is provided with a work feed mechanism 7 that feeds the work W in the cutting direction for cutting the wire 54 and a balancer 8 that holds the work feed mechanism 7 .

<Processing equipment>
The processing device 5 is a cutting mechanism that processes the unprocessed work W clamped by the work holding portion 63 of the clamp device 6 . The processing device 5 includes a pair of processing rollers 51 and 52 that are arranged facing each other in the horizontal direction at an appropriate interval, a wire 54 that cuts the work W wound around the processing roller 51 and the processing roller 52, and a processing device. It comprises a drive motor (not shown) for rotating the cleaning rollers 51 and 52 and a bracket 55 . The processing device 5 is installed on a base (not shown) in the vicinity of the column 3 with a bracket 55 interposed therebetween.

The workpiece W consists of a plurality of workpieces arranged side by side along the axial direction of the processing rollers 51 and 52 (only one workpiece is omitted in the accompanying drawings). When the wire saw 1 is operated, the wire 54 runs between the processing rollers 51 and 52, and the work W held by the clamp device 6 is lowered toward the processing device 5 by the work feed mechanism 7, and the wire 54 is moved. It is cut by being pressed against.

The processing rollers 51 and 52 are rotated by a driving motor (not shown) so that the wire 54 is driven only between the processing rollers 51 and 52 driven via a transmission mechanism (not shown) including pulleys, belts, and the like. configured to run. The number of processing rollers 51 and 52 may be at least one pair, and may be three or more as long as they are arranged in parallel with a space therebetween.

The wire 54 is, for example, a processing wire made up of a single wire rod. The wire 54 is driven by the processing rollers 51 and 52 so as to repeat forward movement and backward movement by a fixed amount to advance stepwise as a whole or to advance continuously in one direction.

<Clamp device>
As shown in FIG. 1 , the clamp device 6 is a holding mechanism for clamping the work W when the work W is processed by the processing device 5 . The clamping device 6 clamps the unprocessed work W, presses the work W against the wire 54 of the processing device 5 for processing, and holds the work W until the work W after processing is unclamped. . The clamping device 6 includes a work holding portion 63 that holds the work W, a clamp portion 62 that clamps the work holding portion 63, a work feed table 61 that moves the work holding portion 63 and the clamp portion 62 up and down by the work feed mechanism 7, consists of

<Work feeding mechanism>
The work feed mechanism 7 moves the work W between a machining position where the work W is cut by the wire 54 and a work exchange position where the machined work W and the unmachined work W are exchanged. is a transfer device. The work feed mechanism 7 also functions as an elevating device for elevating the work W when the work W is processed. The work feed mechanism 7 is composed of a linear motor 70 .

<Linear motor>
As shown in FIG. 1, the linear motor 70 is a drive source for moving the saddle 4 vertically. The linear motor 70 includes a base 75, a stator 74 fixed to the base 75 and having a permanent magnet 73, a mover 72 provided movably relative to the stator 74 and having an armature winding 71, It consists mainly of The linear motor 70 is configured such that when an alternating current is supplied to the armature winding 71 from a power supply device (not shown), the mover 72 is driven. At this time, since the armature winding 71 generates heat, a cooling device (not shown) for cooling the heat is arranged in contact with the armature winding 71 . The stator 74 is fixed to the base 75 and the mover 72 is arranged on the saddle 4 . Base 75 is connected to column 3 . Linear motor 70 is electrically connected to a power source (not shown) via controller 10 .

<Balancer>
As shown in FIG. 1, the balancer 8 offsets the weight of the saddle 4, the weight of the movable part of the work feed mechanism 7, and the reaction force (machining resistance) generated when the work W is cut by the wire 54. It is a device for applying a force to the saddle 4 in a direction to control and support the saddle 4 at an appropriate position. The balancer 8 mainly consists of a cylinder device 80 . Further, to give a specific example, the balancer 8 includes a cylinder device 80, a control valve 90, a controller 10, and a cylinder pump P1 of a cylinder hydraulic unit (not shown). The balancer 8 is controlled by the controller 10 to move synchronously with the linear motor 70 .

<Cylinder device>
As shown in FIGS. 1 and 3, the cylinder device 80 is a device that supports the work feed mechanism 7 and the like in order to cancel the weight of the work feed mechanism 7 and the like while moving in the vertical direction. The cylinder device 80 includes a cylinder 81 , a piston rod 83 and a saddle connecting member 84 . The cylinder device 80 supports the saddle 4 by operating a piston (not shown) with oil sent from a cylinder hydraulic unit (not shown) through a control valve 90 .

The cylinder 81 accommodates a piston (not shown), a piston rod 83 , and oil supplied from a cylinder hydraulic unit (not shown) through a control valve 90 . The cylinder 81 is attached to the saddle 4 that supports the clamp device 6 that holds the workpiece W. As shown in FIG. The cylinder 81 is connected via a control valve 90 to a cylinder pump P1 of a cylinder hydraulic unit (not shown). The pressure of the oil supplied to the cylinder 81 is controlled by the controller 10 according to the weight of the saddle 4, the weight of the mover 72 of the linear motor 70, and the machining resistance when machining the workpiece W (see FIG. 1). It can be set arbitrarily.

The piston rod 83 has a lower end integrally fixed to a piston (not shown) and an upper end connected to a saddle connecting member 84 .

The saddle connecting member 84 is a member for connecting the upper end portion of the piston rod 83 and the upper end portion of the saddle 4 so that the saddle 4 can be raised and lowered by the cylinder device 80 .
The cylinder device 80 supports the saddle 4 by raising and lowering the cylinder 81 with the hydraulic pressure of the oil.

The control valve 90 is a control valve for driving the piston 82 that varies the pressure of oil supplied to the cylinder 81 of the balancer 8 . The control valve 90 is connected between the cylinder pump P<b>1 of the cylinder hydraulic unit and the cylinder 81 .
A cylinder pump P<b>1 of the cylinder hydraulic unit is a pump that generates hydraulic pressure for driving the cylinder 81 forward and backward and discharges oil into the cylinder 81 .
The control valve 90 and the cylinder pump P1 supply power to the cylinder 81 according to the weight of the saddle 4, the weight of the mover 72 of the linear motor 70, and the machining resistance when machining the workpiece W (see FIG. 1). It has a function to change the pressure of the oil to be applied. Control valve 90 comprises a proportional electromagnetic pressure reducing valve and is driven by controller 10 .

<Controller>
The controller 10 is a control device that can arbitrarily set a command value for the pressure of the oil supplied to the cylinder 81 of the balancer 8 to the control valve 90 in accordance with the cutting position of the workpiece W. Further, as described above, the controller 10 controls the control valve 90 and the cylinder pump P1 to control the weight of the saddle 4, the weight of the mover 72 of the linear motor 70, and the weight of the workpiece W (see FIG. 1) when machining the work W (see FIG. 1). It also has a function to drive according to machining resistance. In other words, the controller 10 changes the command value of the pressure of the fluid supplied to the cylinder device 80 to the control valve 90 when cutting the work W with the wire 54, so that the reaction force generated when the work W is cut is reduced. , and the weight of the movable portion of the work feed mechanism 7 are controlled to offset each other, and the amount of deformation of the machine can be kept constant.

It should be noted that the reaction force generated during cutting always changes depending on the size, material, cutting area of the work W, sharpness of the wire 54 used, and the like.

[Action]
Next, operation of the wire saw 1 according to the embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG.

As shown in FIG. 1, first, the workpiece W is attached to the workpiece holder 63 . By driving the linear motor 70 and lowering the workpiece W, the workpiece W is pressed against the wire 54 of the processing device 5 and cut.

The balancer 8 can cancel the weight of the saddle 4, the weight of the movable part of the work feeding mechanism 7, and the machining resistance when machining the work W, and support the work W in a stable state. Therefore, the balancer 8 can reduce the load lifted by the linear motor 70, so that the linear motor 70 can be miniaturized.

As described above, the wire saw 1 according to the embodiment of the present invention includes a wire 54 for cutting a work W, a plurality of processing rollers 52 around which the wire 54 is wound, and the wire 54. and a balancer 8 that holds the work feed mechanism 7. The balancer 8 is provided with a reaction force generated when the work W is cut by the wire 54, A force is applied to the work feed mechanism 7 in a direction that offsets the weight of the movable portion of the work feed mechanism 7 and the weight of the work W.

According to such a configuration, the balancer 8 cancels the reaction force generated when cutting the work W with the wire 54, the weight of the movable portion of the work feed mechanism 7, and the weight of the work W. Since the force is applied to the work feed mechanism 7, the force applied to the work feed mechanism 7 can be kept constant even if the cutting resistance during cutting of the work W changes. For this reason, the present invention has a work feeding mechanism 7 that does not deform due to cutting resistance even if the cutting resistance changes due to changes in the size of the work W, the size of the cross-sectional area of the work W, and changes in machinability during machining. A wire saw 1 can be provided. Therefore, the wire saw 1 can keep the force applied to the work feed mechanism 7 constant, and can cut the work W with high accuracy.

Further, as shown in FIG. 1, the wire saw 1 includes a cylinder device 80 that constitutes the balancer 8, a control valve 90 for varying the pressure of the fluid supplied to the cylinder device 80, and the fluid supplied to the cylinder device 80. a controller 10 that can arbitrarily set a command value for the pressure control valve 90 according to the cutting position of the work W, and the controller 10 controls the cylinder device 80 when cutting the work W with the wire 54 By varying the command value of the pressure of the supplied fluid to the control valve 90, the reaction force generated when cutting the workpiece W, the weight of the movable part of the workpiece feed mechanism 7, and the weight of the workpiece W can be adjusted. Controls the force in the direction of cancellation.

According to this configuration, the controller 10 changes the command value of the pressure of the fluid supplied to the cylinder device 80 to the control valve 90 when cutting the work W with the wire 54, so that the pressure generated when cutting the work W is changed. A force in a direction that offsets the reaction force, the weight of the movable portion of the work feed mechanism 7, and the weight of the work W is controlled. Therefore, the balancer 8 can reduce the load lifted by the work feed mechanism 7, so that the work feed mechanism 7 can be made smaller, and the entire column 3 can be made smaller and the cost can be reduced.

[Modification]
It should be noted that the present invention is not limited to the above embodiments, and various modifications and changes are possible within the scope of its technical ideas, and the present invention does not extend to these modified and changed inventions. Of course. In the following, the same reference numerals are given to the structures already explained, and the explanation thereof will be omitted.
FIG. 4 is a schematic vertical cross-sectional view of a main part showing a modification of the wire saw according to the embodiment of the present invention. 5 is an enlarged view of a main part of FIG. 4. FIG.

In the above embodiment, as shown in FIG. 1, the wire saw 1 provided with the linear motor 70 as the work feed mechanism 7 for moving the work W in the vertical direction was described as an example, but the present invention is not limited to this. .

As shown in FIG. 1 or FIG. 4, the work feed mechanisms 7 and 7A include a linear motor 70 for moving the work W in the vertical direction, or a ball screw mechanism 71A for moving the work W in the vertical direction, and the ball screw mechanism 71A for moving the work W in the vertical direction. and a motor 70A for driving 71A.

In this case, as shown in FIG. 4 or 5, the work feed mechanism 7A includes a ball screw mechanism 71A consisting of a nut portion 72A and a screw shaft portion 73A, a motor 70A, a sensor S1, and a sensor S1 that connects the nut portion 72A to a sensor S1. and a controller 10 for driving the motor 70A.

The sensor S1 is a strain sensor that detects a resistance value that changes when the saddle 4A interposed between the nut portion 72A and the work feed table 61 expands and contracts, or detects a force (mass, torque) applied to the saddle 4A. It consists of a load cell that senses and converts it into an electrical signal. Therefore, the sensor S1 can detect the load applied to the work feed table 61 and the weight of all vertically movable components such as the balancer 8, the work feed mechanism 7A, and the saddle 4A. Sensor S1 is electrically connected to controller 10 .

The controller 10 can control the balancer 8 according to the reaction force during processing detected by the sensor S1 to keep the deformation amount of the machine constant and the posture of the machine constant. For this reason, the wire saw 1A keeps the force applied to the work feed mechanism 7A constant by controlling the value of the sensor S1 to be constant by the controller 10 even if the cutting resistance during cutting of the work W changes. can let you Therefore, the wire saw 1A can further improve the cutting accuracy of the workpiece W.

The reaction force during machining can also be known from the load factor (motor current value) of the linear motor 70 or the motor 70A that drives the ball screw. A motor 70A controls the position of the clamping device 6 . If the machining load is constant, the load factor of the motor 70A will be constant wherever the clamping device 6 is positioned. If the load on the motor 70A changes depending on the position of the clamp device 6, the machining load also changes. Therefore, when the balancer 8 is controlled so that the load factor of the motor 70A is constant, the force applied to the work feeding mechanism 7A is constant.

According to this configuration, the work feeding mechanism 7 is composed of the linear motor 70 as shown in FIG. to move. Therefore, since the linear motor 70 is not worn and deteriorated, it can move smoothly during cutting. Moreover, the wire saw 1 can eliminate maintenance work for the parts of the linear motor 70, and can improve maintainability.
Further, since the work feed mechanism 7A includes the ball screw mechanism 71A and the motor 70A, the ball screw mechanism 71A has low frictional resistance, so that the movement during cutting can be smoothed.

1, 1A wire saw 5 processing device 7, 7A work feeding mechanism 8 balancer 10 controller 52 processing roller 54 wire 70 linear motor 70A motor 71A ball screw mechanism 80 cylinder device 90 control valve W work

Claims (3)

a wire for cutting the workpiece;
a plurality of processing rollers around which the wire is wound;
a work feed mechanism for feeding the work in a cutting direction for cutting the work with respect to the wire;
a balancer that holds the work feeding mechanism,
The balancer applies a force to the work feed mechanism in a direction that offsets the reaction force generated when the work is cut by the wire, the weight of the movable portion of the work feed mechanism, and the weight of the work. A wire saw characterized by: a cylinder device that constitutes the balancer;
a control valve for varying the pressure of the fluid supplied to the cylinder device;
a controller capable of arbitrarily setting a command value of the pressure of the fluid supplied to the cylinder device to the control valve according to the cutting position of the work,
The controller changes the command value of the pressure of the fluid supplied to the cylinder device to the control valve when cutting the work with the wire, thereby generating a reaction force generated when cutting the work. 2. The wire saw according to claim 1, wherein the force in the direction of canceling out the weight of the movable portion of the work feeding mechanism and the weight of the work is controlled. the work feed mechanism includes a linear motor for moving the work in the vertical direction;
Alternatively, the wire saw according to claim 1 or 2, further comprising: a ball screw mechanism for moving the work in the vertical direction; and a motor for driving the ball screw mechanism.

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