KR20050051900A - The control method for automatic traversing in wire saw machine - Google Patents

Abstract

The present invention relates to an automatic traversing control method for uniform winding of a saw wire in a wire saw device.

The method comprises the steps of: inputting an initial limit value of the traversing device and upper and lower limits of the dancer position; Driving (200) a wire saw device; Step 300 of periodically inputting the position of the dancer and the rotational speed of the main motor; Comparing 400 the positions of the dancers; Controlling 500 the traversing device according to the position of the dancer or stopping 500 'the wire saw device; In the case of controlling the traversing device, the stop signal input determination step 600 is performed, and there is a technical feature of the method of controlling the limit value of the traversing device using the position of the dancer.

In the automatic traversing control method of the wire saw device of the present invention, the control of the traversing device is efficiently controlled by using the movement of a dancer installed just before the traversing device as a basic control input signal, thereby significantly reducing the occurrence rate of disconnection of the saw wire. In addition to excellent performance, there is an advantage that the productivity is improved.

Description

The control method for automatic traversing in wire saw machine}

The present invention relates to an automatic traversing control method for uniform winding of a saw wire, and more particularly, a saw wire which is unsealed from a supply reel in a wire saw device for cutting a semiconductor material or a magnetic material into a saw wire. Is installed in front of the winding reel to be cut and wound so that the winding of the saw wire is reciprocated in parallel with the axial direction of the winding reel so that the winding of the saw wire is made uniform under a certain tension. The left and right limit values determined in front of the traversing device are corrected in real time according to the movement of dancers moving up and down according to the change of tension so that the tension of the saw wire is kept constant. Automatic traversing control method of wire saw device to ensure uniform winding It relates.

In general, a wire saw device is a device capable of simultaneously cutting a plurality of sheets while having a flat cutting surface when cutting ingots for semiconductor wafers, cemented carbides including ceramics, etc., as shown in FIG. 1, mounted on a supply reel 11. The saw wire S which is supplied from the bobbin B, which has been unsealed, has a mouth traversing device 12, a plurality of mouth guide rollers 13 having a dancer 14 in the middle, and three rollers having a reversed cross section. The bobbin mounted on the winding reel 19 via the main roller 15 installed parallel to each other to form a vertex of a triangle, a plurality of exit guide rollers 16 having a dancer 17 interposed therebetween, and an exit traversing device 18. Rewinding to (B), the main roller 15, the supply reel 11, the winding reel 19 is connected to the drive motor capable of reverse and reverse, respectively, these motors are linked together so that the tension of the saw wire (S) Adjusted.

In addition, a plurality of circular arc-shaped grooves are formed at regular intervals on each outer circumferential surface of the three main rollers 15 so that the saw wire S passes through the main rollers reciprocating a plurality of times in parallel. It is located between the two main rollers on the upper part of the cutting apparatus.

Cutting process of the cutting object 2, such as a semiconductor ingot, using the wire saw device which consists of a structure as mentioned above, the saw | wound which is wound between the main roller 15 and the guide rollers 13 and 16 by driving each drive motor. After the saw wire S is transferred from the supply reel 11 to the take-up reel 19 while maintaining the proper tension on the wire S, the cutting object 2 located directly above the center of the two main rollers is lowered. The cutting object 2 is cut into several sheets by bringing it into close contact with the saw wire S.

The wire saw device as described above is generally connected and controlled by a computer-configured control unit, and inputs data on various cutting work conditions such as the feed speed of the saw wire before cutting and the specification of the cutting object. And it is controlled to perform the optimal cutting operation by calculating the feed back data input from each drive motor.

As described above, it is very important to maintain a constant tension of the saw wire in contact with the hard cutting object in the cutting operation using the saw wire. Therefore, it is necessary to precisely control the interlocking speed between the drive motors. Of course, the feed reel in which the saw wire is wound, and the searing and winding in the take-up reel must be made uniform under a range of tensions.

In particular, the body of the bobbin mounted on the winding reel and the supply reel to unwind or wind the saw wire is cylindrical, and the saw wire is sequentially stacked while the saw wire moves from one end to the other end of the bobbin and the other end to one end of the bobbin. In this way, the traversing device is to induce a reciprocating movement of the sea circle and the wound saw wire while reciprocating in the left and right directions.

In addition, a dancer capable of reciprocating upward and downward in accordance with the change in the tension of the saw wire is provided between the traversing device and the guide roller to maintain a constant tension by absorbing the change in wire tension.

That is, the dancer rises when the tension of the saw wire increases, and descends when the tension of the saw wire decreases, so that the tension applied to the saw wire is kept constant.

As described above, a traversing device and a dancer are installed to uniformly and uniformly wind the saw wire or the sea area. Looking at the conventional traversing control method as follows.

Conventionally, before cutting, the operator inputs the bidirectional movement limit value of the traversing device in advance, thereby determining the distance that the traversing device must reciprocate during the operation, and the limit value is not input by the operator when the machine stops. Otherwise, the traversing device is to be reciprocated constantly within that range.

However, as the winding wire is continuously wound on the bobbin mounted on the winding reel, as the winding diameter increases, the winding pressure applied to the flanges at both ends of the bobbin increases, and as a result, there are some differences in the flange structure of the bobbin. As the flanges on both ends of the bobbin open outwardly, the winding surface wound around the cylindrical body of the bobbin to be wound does not form a horizontal plane over the entire length of the bobbin, and the winding surface yarn end contacting the flange has an upper side or a lower side. Will tilt.

As a result, when the saw wire is wound around the bobbin flange, the up and down movement of the dancer is greatly increased, causing uneven tension of the saw wire, and impacting the saw with the uneven tension. This results in disconnection of the saw wire during the cutting operation, resulting in poor cutting surface of the wafer being cut, thereby reducing productivity.

The present invention has been made to solve the problems of the traversing control method for the winding of the saw wire in the conventional wire saw device, the dancer by the change of the winding surface in the vicinity of the bobbin flange according to the winding pressure of the saw wire SUMMARY OF THE INVENTION An object of the present invention is to provide a control method of a traversing apparatus capable of detecting a movement and correcting bidirectional movement limit values of a traversing apparatus in real time to maintain a winding surface in a horizontal plane and minimizing disconnection of a saw wire. .

The above object of the present invention is achieved by control logic that calculates a new traversing limit value using the up and down positions of the dancer and the advancing speed of the saw wire.

The automatic traversing control method of the wire saw device of the present invention continuously grasps the winding non-uniformity caused by the opening of the bobbin flange as the winding progresses, thereby appropriately changing the traversing limit value that determines the moving distance of the traversing device. Through the method, the winding surface to the bobbin is always horizontal, and the means for controlling this is the control logic.

As shown in FIG. 2, the control logic stores a ROM (ROM) 21 in which the control logic is stored, an upper and lower position range of the dancer previously input by the operator, and an initial limit value of the traversing device. RAM 22, a microprocessor 23 that calculates a new limit value according to the control logic of the ROM from the value stored in RAM, and gives a control command, and displays various input values and output values on the screen. Note is implemented by a controller configured to include a monitor 24.

The control logic implemented by the controller compares the rotation speed and the dancer position of the main motor as input values with respect to the input traversing limit value, which is the initial value input by the operator, and the allowable range of the dancer position. The output of the new traversing limit is controlled by controlling the servo motor drive drive of the traversing device, and the control period can be set to the number of times the traversing device is located on the traversing limit value or the travel distance of the saw wire. .

That is, the automatic traversing control method of the wire saw device of the present invention has a technical feature of the present invention to detect the position of the dancer and newly calculate the optimal limit value of the traversing device in real time according to the position change within the allowable range.

At this time, the control logic stored in the ROM and applied to the control of the traversing device is shown in Equation 1 below.

In the above formula, α is a correction coefficient, h (x) is a function for the up and down position of the dancer, V (y) is a function of the speed of the saw wire calculated by the number of revolutions of the main motor.

In this case, h (x) and V (y) can be represented by the following equation, respectively.

In the above formula, L is the length of the dancer arm (not shown), x is the rotation angle of the dancer arm, D is the diameter of the main roller driven by the main motor, y is the rotation speed of the main motor.

The correction coefficient α is a coefficient for determining the control correction degree for each of the calculated h (x) and V (y), and has a value in the range of 0 to 10. For example, α = 0 means that In this case, α = 10 is a correction output for the control value 10 times when α = 1.

An automatic traversing control method of the wire saw device of the present invention for controlling a traversing device by calculating a new traversing limit value according to Equation 1 will be described below with reference to FIG. 3.

The method comprises the steps of: a worker inputting an initial limit value of a traversing device and an upper and lower limit value of a dancer position; Driving the wire saw device to start a cutting operation (200); Step 300 of periodically inputting the position signal of the dancer and the rotational speed of the main motor; Comparing 400 the upper and lower limits of the preset dancer position with the input position of the dancer; Controlling the traversing device using a controller if the input dancer's position is within an acceptable range (500 ') or stopping the wire saw device (500') if it is outside the acceptable range; In the case of controlling the traversing device 500, the stop signal input determination step 600 transitions to either one of the steps 500 ′ of stopping the wire saw device and 400 comparing the position of the dancer. Is through.

Looking at the mechanical aspects of the present invention control method as described above based on Figure 1 as follows.

The saw wire (S) passing through the main roller 15 passes through the dancer (17) and the traversing device (18) while proceeding to the bobbin (B) side mounted on the take-up reel (19), the tension of the saw wire In this maintained state, the traversing device moves between the traversing limit values on both the left and right sides and winds the saw wire on the bobbin of the reel with a predetermined pitch.

At this time, if the traversing limit value input by the operator is not suitable for the normal odor of the saw wire, or if the bobbin flange opens as the winding progresses, as shown in FIG. 3, the winding surface of the adjacent bobbin flange (f) ( The phenomenon that S _U ) (S _D ) becomes higher or lower than the winding surface S _C of the bobbin center part occurs.

That is, when the saw wire is wound up normally, the winding surface S _U (S _D ) adjacent to the bobbin flange f and the winding surface S _C of the bobbin center remain horizontal under a given traversing limit value. The position of the dancer also flows stably up and down within a certain range.

However, when the traversing limit value becomes excessively the winding end, as the winding operation proceeds, the winding diameter of the sawing wire wound around the winding end, i.e., the bobbin flange, becomes larger than the winding diameter of the bobbin center, and the constant saw wire is advanced. Under the speed, the dancer moves upward due to an increase in the amount of winding near the bobbin flange.

And, unlike the above, if the traversing limit value does not reach the end of the winding, the amount of winding of the wire at the winding end becomes insufficient as the winding operation proceeds, and as a result, the amount of winding of the bobbin flange adjacent to the constant saw wire at a running speed The decrease causes the dancer to move downward.

Therefore, if the amount of winding of the saw wire becomes excessive or insufficient at the winding end of the bobbin flange adjacent portion, the dancer swings upward or downward when winding at the winding end, and as a result, the progress of the saw wire becomes unstable. At the same time, the tension of the saw wire is also severely changed. The position of the dancer's up and down movements and the number of rotations of the drive motor are input, and the appropriate traversing limit value is determined according to the winding state at the actual winding end under the specific saw wire speed. It is the method of the present invention to correct in real time so that the saw wire winding state at the winding end is kept horizontal.

In other words, when the dancer's position is moved upward at the winding end, a new traversing limit value is calculated and applied so that the currently applied traversing limit value is moved inward. By newly calculating and applying the traversing limit value to move the sink limit value outward, stable winding can be realized.

Equation 1 applied to the above-described control method has a winding nonuniformity and a dancer's vertical movement distance being proportional to each other, and under the same degree of winding nonuniformity, the dancer's movement distance increases as the saw wire progresses. The correction value of the traversing limit value is applied in proportion to h (x) and inversely proportional to V (y).

In addition, as a control method different from the above, it is also preferable to use the difference in the number of revolutions of the bobbin instead of the h (x) which is a function of the up and down position of the denser.

That is, in general, the rotation speed of the bobbin is controlled so that the denser is maintained at the center position with respect to the vertical movement of the denser.In the case of controlling the rotation speed of the winding bobbin, when the denser goes down, the rotation speed of the winding bobbin is rapidly increased. In the case of upward movement, when the denser rises up, the rotation speed of the winding bobbin is slowed to prevent the denser from moving upward, and the contrary control is made in the supply bobbin.

In general, the denser arm is positioned at the center of the bobbin, and the rotation speed of the bobbin is changed at both ends of the bobbin winding surface according to the winding surface state of the saw wire. It can be expressed as

In the above formula, β is a correction coefficient and ΔV (z) is (the bobbin rotation speed at the bobbin winding surface center portion winding)-(the bobbin rotation speed at the winding edge of each bobbin winding surface).

In addition, said Formula 1 and 3 can also be used together, and in that case, it becomes like following Formula 4.

As described above, the automatic traversing control method of the wire saw device of the present invention uses the movement of a dancer installed just before the traversing device as a basic control input signal, so that the control deviation of the traversing device is small and efficient. Not only is the occurrence rate of disconnection due to the nonuniformity of the tension and the impact reduced, but also the workability is excellent, high-quality wafers are produced and productivity is improved.

1 is a schematic configuration diagram of a wire saw device;

2 is a block diagram of an embodiment of the present invention.

3 is a control flow diagram of an embodiment method of the present invention.

4 is a partial front view of a winding bobbin showing a wound state of a saw wire;

           ((Explanation of symbols for main part of drawing))

            2. Cutting object 11. Supply reel

           12,18. Traversing Device 13,16. Guide roller

           14,17. Step 15. Main Roller

           19. Reel 21. Romans

           22. RAM 23. Microprocessor

           24. Monitor

           B. Bobbin S. Saw Wire

Claims (5)

A method of controlling the traversing of a saw wire wound when the saw wire is wound in a wire saw device for cutting a semiconductor material or the like, the method comprising: inputting an initial limit value of the traversing device and an upper / lower limit value of a dancer position to a controller ( 100); Driving a wire saw device to feed the saw wire to the take-up reel 200; Periodically inputting the position signal of the dancer and the rotation speed of the main motor during the transfer of the saw wire; Comparing a 400 of a preset dancer position with a dancer's position periodically input; If it is determined that the input dancer position is within the allowable range, the control proceeds to step 500 of controlling the traversing device with the controller, and if it is determined to be out of the allowable range, stopping the wire saw device 500 'and ; In the step 500 of controlling the traversing device, a stop signal is shifted to any one of steps 500 'of stopping the wire saw device and 400 comparing the position of the dancer according to whether the stop signal is input. Auto-traversing control method of the wire saw device characterized in that it comprises an input determination step (600). 2. The controller of claim 1, wherein the controller comprises: a RAM (21) in which control logic is stored, a RAM (22) for storing the upper and lower position ranges of the dancer and an initial limit value of the traversing device, and a value stored in the RAM. A microprocessor 23 for calculating a new limit value according to the control logic of the ROM from the controller and giving a control command according to an output value, and a monitor 24 for displaying a stored value and an output value. How to control automatic traversing of saw devices. 3. A method according to claim 2, wherein the control logic stored in the ROM (21) consists of the following equation. Equation Where α is a correction factor, h (x) is a function of the dancer's up and down position, V (y) is a function of the saw wire calculated from the main motor speed, L is the length of the dancer arm, and x is The rotation angle of the dancer arm, D is the diameter of the main roller driven by the main motor, y is the rotation speed of the main motor. 3. A method according to claim 2, wherein the control logic stored in the ROM (21) consists of the following equation. Equation Where β is a correction factor, V (y) is a function of the saw wire calculated as the main motor speed, D is the diameter of the main roller driven by the main motor, y is the rotation speed of the main motor, ΔV (z ) Is (the bobbin rotation speed at the time of winding of a bobbin winding surface center part)-(bobbin rotation speed at the winding of each edge part of a bobbin winding surface). 3. A method according to claim 2, wherein the control logic stored in the ROM (21) consists of the following equation. Equation Where α and β are correction coefficients, h (x) is a function of the dancer's upper and lower positions, V (y) is a function of the saw wire calculated from the main motor revolution, L is the length of the dancer arm, x is the angle of rotation of the dancer arm, D is the diameter of the main roller driven by the main motor, y is the number of revolutions of the main motor, and V (y) is a function of the saw wire calculated as the number of revolutions of the main motor, ΔV (z ) Is (the bobbin rotation speed at the time of winding of a bobbin winding surface center part)-(bobbin rotation speed at the winding of each edge part of a bobbin winding surface).