JP7267684B2 - Wire saw operation parameter setting method and wire saw - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method of setting operation parameters of a wire saw for cutting a workpiece made of a brittle material such as a semiconductor material, a magnetic material, or ceramics, and a wire saw.

There are various types of wires with different diameters and materials that are used for cutting a workpiece with a wire saw, and a wire suitable for working conditions is selected. Then, the operation parameters of the wire saw are set according to the selected wire. By setting these parameters, the tension applied to the wire, the feed speed of the workpiece, and the running speed of the wire can be adjusted so that the required processing accuracy and processing speed can be obtained without breaking the wire. do.

By the way, in the wire saw disclosed in Patent Document 1, in order to determine whether or not the wire can be repeatedly used, a mechanical sensor detects the diameter of the wire sent out from the processing portion of the work, and the wire is repeatedly used. Acceptance or rejection is displayed on the display unit.

In the wire saw disclosed in Patent Document 2, a wire made of a magnetic material is magnetized while the wire is running, and the magnetic force thereof is detected in order to prevent wire breakage and to enable accurate processing. and the wire diameter is detected from the detected magnetic force. Then, when the wire diameter becomes equal to or less than a predetermined value at which there is a risk of wire breakage, an instruction to replace the wire is given on the display unit.

In the wire saw disclosed in Patent Document 3, in order to prevent disconnection of the wire with fixed abrasive grains, a laser sensor detects the diameter of the wire during cutting of the workpiece, and detects when the diameter of the wire falls below the usage limit. If so, the operation of the wire saw is stopped.

JP-A-8-174402 JP-A-10-264007 JP-A-11-188599

In the wire saws of Patent Documents 1 to 3, the diameter of the wire traveling for cutting the work is detected during traveling to determine whether or not the wire can be used. In other words, the diameter of the wire is detected after the cutting of the work is started. Therefore, no consideration is given to the matching between the wire saw and the wire before cutting the workpiece. Therefore, when the same type of wire is used in different wire saws, even if the wire saws are of the same model, there is a risk that the wire durability, processing accuracy, etc., will differ due to individual differences in the devices.

Therefore, in the wire saw, it is necessary to set operating parameters for each device according to the type of wire and adjust the tension applied to the wire to an appropriate value in order to achieve matching between the wire saw and the wire. However, in the conventional wire saw, the operator determines the type of wire and manually sets the operating parameters. For this reason, there is a possibility that the setting may be forgotten or the setting may be input erroneously. In such a case, an inconvenient situation such as wire cutting or a decrease in processing accuracy may occur.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a wire saw operation parameter setting method and a wire saw that can automatically match a wire saw and a wire before cutting a workpiece.

In order to achieve the above object, in the wire saw operation parameter setting method of the present invention, a wire is caused to travel in a circulating state between a plurality of processing rollers under the control of a control device, and the wire between the processing rollers is is carried out in a wire saw in which a work is processed and fed to a cutting area of , and the work is cut by the wire. In the present invention, prior to machining the workpiece, the control device determines the diameter of the wire from the vibration applied to the wire by the vibration applying means , and determines the diameter of the wire of the wire saw based on the diameter of the wire. tension, the running speed of the wire, or the working speed of the workpiece is set.

In the present invention, by vibrating the wire prior to machining the workpiece, the operating parameters of the device can be automatically set based on the diameter of the wire. matching can be achieved. Therefore, it is possible to prevent forgetting to set operation parameters and input errors in setting, thereby preventing wire cutting, deterioration of processing accuracy, and the like.

Further, in the wire saw of the present invention, the wire travels in a circulating state between the plurality of processing rollers, and the work is processed and fed to the wire cutting region between the processing rollers to cut the work by the wire. It is embodied in a wire saw adapted to In the present invention, vibration imparting means for imparting vibration to the wire prior to machining of the work, detecting means for detecting vibration of the wire due to the imparting of vibration, and wire vibration based on detection by the detecting means. A determination means for determining a diameter, and a setting means for setting operation parameters relating to the tension of the wire of the wire saw, the running speed of the wire, or the processing speed of the workpiece based on the determination result of the determination means. characterized by

Therefore, in the present invention, prior to machining of the workpiece, the variation imparting means imparts vibration to the wire, and the detection means detects the vibration of the wire due to the imparting of the vibration . Further, the diameter of the wire is determined by the determination means based on the detection by the detection means, and the operating parameters of the apparatus are set by the setting means based on the determination result of the determination means.

Therefore, as described above, matching between the wire and the device can be achieved before machining the workpiece. Therefore, it is possible to prevent forgetting to set operation parameters and input errors in setting, thereby preventing wire cutting, deterioration of processing accuracy, and the like.

In the present invention, it is possible to automatically set the operating parameters for matching the wire saw and the wire before cutting the workpiece. It exhibits the effect of improving the durability of processing and wires.

The schematic diagram which shows a wire saw. FIG. 2 is a block diagram showing the electrical configuration of the wire saw; 4 is a flowchart showing the operation of the first embodiment; 4 is a diagram showing movements of the dancer arm; FIG. Diagram showing the physical behavior of the wire. A table showing the relationship between wire spring constant and wire thickness. A table showing the relationship between wire thickness and operating parameters. 8 is a flowchart showing the operation of the second embodiment;

(First embodiment)
A first embodiment embodying the present invention will be described below with reference to FIGS. 1 to 7. FIG.
As shown in FIG. 1, a plurality of processing grooved rollers (hereinafter referred to as processing rollers) 11 are rotatably supported on parallel axes on a device frame (not shown) of the wire saw. Usually, two to four processing rollers 11 are installed, and in this embodiment, two processing rollers are installed. A large number of annular grooves (not shown) are formed at equal pitches on the outer periphery of the processing roller 11, and a wire 13 for cutting a workpiece is spirally wound around the annular grooves. The wire 13 is of a fixed abrasive grain type in which abrasive grains such as diamond or white alundum are fixed and held by using a binder on the outer circumference of the core wire made of carbon steel.

As one processing roller 11 is alternately rotated in one direction and the opposite direction by the motor 12 shown in FIG. Therefore, the wire 13 travels in one direction and in the opposite direction together with both processing rollers 11 in a circulating state. Both ends of the wire 13 are wound around bobbins 15 rotated by a motor 20, respectively. By the rotation of the bobbin 15 synchronized with the running of the wire 13, the wire 13 is unwound from the one bobbin 15 through the traverse roller 17 of the one traverser 16 that is reciprocally movable in the axial direction of the bobbin 15. It is wound on the other bobbin 15 via the traverse roller 17 of the other traverser 16 .

In the travel area of the wire 13 between the processing roller 11 and the traverser 16, there is provided a pair of rollers 21 for applying an appropriate tension to the wire 13 through dancer rollers 21 at the tip by the driving force of a dancer motor 18 which is a servomotor. of dancer arms 19 are provided. The dancer motor 18 and the dancer arm 19 constitute variation imparting means , which is vibration imparting means . A guide roller 22 for guiding the wire 13 is provided between the dancer roller 21 and the processing roller 11 .

The shaft of the traverse roller 17 and the shaft of the guide roller 22 are provided with sensors 25 and 26 as detection means comprising load cells for outputting detection signals corresponding to the tension acting on the wire 13, respectively. .

Above the wire 13 between the processing rollers 11, an elevating body 23 is installed on the apparatus frame so as to be able to move up and down. Then, the work 27 is pressed against the cutting area of the wire 13 running between the working rollers 11 by the lifting body 23 being fed downward for processing, and cut by the action of the fixed abrasive grains of the wire 13, A large number of wafers are cut at the same time.

As shown in FIG. 2 , the wire saw control device 33 has a central processing unit (hereinafter referred to as CPU) 31 and a storage unit 32 . The control device 33 constitutes determination means and setting means, and the storage section 32 constitutes storage means. The CPU 31 operates the entire wire saw including the roller motor 12 for rotating the processing roller 11, the bobbin motor 20 for rotating the bobbin 15, the dancer motor 18 for operating the dancer arm, and the like. to control. The storage unit 32 stores the program data of the flow chart shown in FIG. 3, as well as various temporary data. A keyboard 34 is operated by an operator to manually input various data.

Next, the action of the wire saw formed as described above will be described.
First, prior to machining the workpiece 27, the wire 13 is attached to the wire saw as shown in FIG. It goes around or passes the dancer rollers 21 .

In this state, the flowchart of FIG. 3 is operated. 3, the program data stored in the storage section 32 proceeds under the control of the CPU 31 before the work 27 is started to be machined. That is, in step S (hereinafter simply referred to as S) 1 in FIG. 3, as shown in FIG. 4, one dancer arm 19 is reciprocally tilted with a predetermined period and amplitude for a predetermined time. Hereinafter, this reciprocating tilting motion will be referred to as vibration. Along with this vibration, the wire 13 undergoes a physical change, and as shown in FIG. 5, the wire 13 exhibits physical behavior as a state change according to its thickness and material. The behavior is stored in the storage unit 32 in S2. The stored behavior appears as a change in the load acting on the sensor 25 of the dancer roller 21, and the change history of the load value is stored in the storage unit 32 as described above.

Then, in S3, the stored load value data is extracted, and in S4, the spring constant, which is the mechanical characteristic of the wire 13, is calculated and stored in the storage unit 32. FIG. In this embodiment, the spring constant is calculated based on the load detection value α from the sensor 25 when the dancer arm 19 is tilted. This calculation of the spring constant may be performed by using a table in which spring constants corresponding to a plurality of different detection values α are set, and extracting the spring constants corresponding to the detection values α from the table, or by setting the spring constants in advance. The spring constant may be calculated by giving the detected value .alpha.

Then, in S5 and S6, the thickness value of the wire 13 is extracted and determined from the table shown in FIG. 6 showing the wire thicknesses related to the spring constant. Then, in S7, the table shown in FIG. 7 associated with the wire thickness value is referred to. This table is set for each wire saw. Then, an operation parameter suitable for the wire thickness is selected from this table, and the parameter is stored in the storage unit 32 and set in S8. Therefore, matching between individual wire saws and the types of wires 13 is ensured.

Next, in S9, an ON operation of the start switch of the wire saw is awaited, and the wire saw is started for machining operation by the ON operation, and the wire saw is operated according to the operating parameters set in S10. Therefore, the tension and running speed of the wire 13 or the machining speed of the work 27 are appropriately adjusted according to the operating parameters, and highly accurate cutting of the work 27 is performed with high efficiency.

Therefore, the present embodiment has the following effects.
(1) Vibration is applied to the wire 13 before cutting the workpiece 27, and the thickness of the wire 13 is recognized by the behavior of the wire 13 based on the application of the vibration. Based on this recognition, matching between the wire saw and the wire 13 is achieved, and parameters corresponding to the wire thickness are automatically set for the wire saw. Therefore, even if the wire 13 is changed to a different type, it is possible to prevent the wire 13 from being cut or the processing precision from being lowered without forgetting to set the parameters or erroneously inputting the setting.

(2) Since the thickness of the wire 13 can be grasped by the vibration of the dancer arm 19 before processing the workpiece 27, the worker can grasp the thickness of the wire 13 and organize and manage the wires 13 by thickness. It is no longer necessary to Therefore, it is possible to eliminate the complexity of the management and setup of the wire 13 .

(3) Since the thickness of the wire 13 can be recognized by vibrating the dancer arm 19, there is no need to provide a dedicated device for recognizing the thickness of the wire 13, and complication of the structure of the wire saw can be avoided. can.

(Second embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. 5 and 8, focusing on the parts different from the first embodiment.

In the second embodiment, the physical attenuation characteristics of the wire 13 are detected in order to determine the thickness of the wire 13. FIG. That is, in the flow chart of FIG. 8, in the behavior detection and storage by the dancer arm 19 in S2 before the start of processing, after the dancer arm 19 has finished vibrating, the sensor 25 detects the residual stretching operation time β of the wire 13 as shown in FIG. It is detected as the behavior of the wire 13 in S2. That is, in S11 shown in FIG. 8, the CPU 31 recognizes the detection output of the sensor 25 representing the time β until the residual expansion/contraction converges, and the attenuation characteristic of the wire 13 is calculated in S12. The calculation of this damping characteristic may be performed according to a table describing a plurality of different damping characteristics corresponding to the length of the convergence time β. may be selected, or may be performed by incorporating the convergence time β value into a predetermined arithmetic expression.

Then, in S5, a table describing the relationship between a plurality of attenuation characteristics and the thickness of the wire 13 is referenced, the thickness of the wire 13 is determined in S6, and the operating parameters suitable for each wire saw are determined in S7. The selected operating parameters are stored in the storage unit 32 in S8. Subsequent operations are the same as those of the first embodiment.

Therefore, in the second embodiment, effects similar to those of the first embodiment can be obtained.
(Change example)
In addition, the said embodiment can also be changed and embodied as follows.

- Combining the first embodiment and the second embodiment. That is, both the spring constant and damping characteristic of the wire 13 are detected from the change in behavior of the wire 13, and the thickness of the wire 13 can be recognized from the data of both.

- The thickness of the wire 13 should be configured so as to capture and recognize different behavior, ie, different mechanical characteristics, from those of the above two embodiments. For example, as shown in FIG. 5, a table in which the responsiveness of the wire 13 is determined by detecting the operation delay γ of the wire 13 with respect to the vibration of the dancer arm 19 and the wire thickness corresponding to the responsiveness is set. and refer to the table to configure it to recognize the wire thickness.

- To be configured to recognize the thickness of the wire 13 by a method different from that of the above two embodiments. For example, by tapping the wire 13, by applying minute vibrations to the wire 13 in a stretched state, or by energizing the wire and detecting the resistance value.

- The detection of the mechanical properties of the wire 13 is performed in a different manner from the previous embodiment. For example, the behavior of the wire 13 may be detected by the sensor 26 of the traverse roller 17 or recognized based on the load acting on the motor such as the dancer motor 18 .

• To embody the present invention in a wire saw of the type that cuts the workpiece 27 while supplying loose abrasive grains to the wire 13 .

DESCRIPTION OF SYMBOLS 11... Roller for processing, 13... Wire, 19... Dancer arm, 25... Sensor, 31... Central processing unit (CPU), 32... Storage part, 33... Control device.

Claims (4)

Under the control of the control device, the wire is caused to travel in a circulating state between the plurality of processing rollers, and the work is processed and fed to the wire cutting region between the processing rollers so that the work is cut by the wire. In a wire saw with
Prior to machining the workpiece, the control device determines the diameter of the wire from the vibration applied to the wire by the vibration applying means , and based on the diameter of the wire, the tension of the wire of the wire saw and the travel of the wire. A method of setting operating parameters of a wire saw for setting operating parameters relating to speed or processing speed of the workpiece. 2. The method for setting operating parameters of a wire saw according to claim 1 , wherein a spring constant of the wire is determined from the vibration of the wire, and a diameter of the wire is determined from the spring constant. 3. A wire saw operating parameter setting method according to claim 1 or 2 , wherein the attenuation characteristic of the wire is determined from the vibration of the wire, and the diameter of the wire is determined from the attenuation characteristic. A wire saw in which a wire travels in a circulating state between a plurality of processing rollers, and a work is processed and fed to a wire cutting area between the processing rollers to cut the work by the wire,
a vibration imparting means for imparting vibration to the wire prior to machining the workpiece;
a detecting means for detecting vibration of the wire due to the application of the vibration;
determination means for determining the diameter of the wire based on detection by the detection means;
a setting means for setting operation parameters relating to the tension of the wire, the running speed of the wire, or the machining speed of the workpiece of the wire saw based on the determination result of the determination means.

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