JP4915235B2 - High-speed thin wire drawing device and disconnection detection method of high-speed thin wire drawing device - Google Patents

Description

  The present invention relates to a device for thinning a metal wire while drawing it from a die using a slip-type capstan, and a disconnection detection method for thinning the metal wire, and in particular, a gold bonding wire for a semiconductor element. The present invention relates to a high-speed thin wire drawing device and a disconnection detection method using this device.

FIG. 3 and FIG. 4 are conceptual diagrams of a general slip-type wire drawing machine that has been conventionally used in wire drawing of metal wires including gold bonding wires.
As shown in FIGS. 3 and 4, the conventional slip-type wire drawing machine feeds a metal wire 1 a wound on a spool of the metal wire unwinding unit 1 with a constant tension by a tension control mechanism 2, thereby drawing a wire drawing tank 11. The wire 5 is drawn by a die 5 installed therein, and is wound around a spool of the metal wire winding unit 6 after the wire drawing.

  In the wire drawing portion of the slip type wire drawing machine, a pair of cone type or straight type ceramic capstans 4A and 4B are arranged before and after the die, and after passing through the first die 5, the right side capstan 4B in the drawing. The left capstan 4A is further made a half turn, then passed through the second die, and then passed through the dice while making a half turn around each capstan, so that the wire diameter is gradually reduced.

  The left and right capstans 4A and 4B rotate in the same direction, and the rotation direction rotates in the same direction as the traveling direction of the metal wire. Further, the left and right capstans 4A and 4B rotate faster than the traveling speed of the metal wires, and slip occurs between the surfaces of the capstans 4A and 4B and the metal wires in contact therewith.

  The section for drawing the metal wire with the die 5 is arranged in the wire drawing tank 11, so that the position of the die 5 is in the liquid or the drawing lubricant is applied from the lubricant shower nozzle 10 in a shower shape. It is in a state that has been. Therefore, the detection of the disconnection is detected by the photoelectric sensors 7 provided before and after the metal wire guide pulley 3 provided on the metal wire pass line, or the rotation speed of the metal wire guide pulley 3 is detected and the metal wire guide pulley is detected. The disconnection is determined by the change in the number of rotations of 3.

The metal wire unwinding unit 1 is driven by a motor 8A, and the metal wire winding unit 6 is driven by a motor 8B. The pair of capstans 4A and 4B are driven by using a single motor 8C and driving the shafts by using a pulley and a belt 9 to transmit rotation. These motors are servo motors or induction motors using inverters. In some cases, the spools of the metal wire unwinding unit 1 and the metal wire winding unit 6 and the capstans 4A and 4B are connected by belts, and all the driving is performed by a single motor. is there. Moreover, as a tension measuring device for a metal wire, for example, there is one shown in Patent Document 1.
JP-A-6-293471

  However, in the wire drawing using the slip-type wire drawing machine having the above-described configuration, the metal wire breakage during wire drawing is likely to occur before and after the die for drawing the metal wire, and the metal wire that has lost its tension after the wire breakage. Entangled with the capstan, causing secondary and tertiary disconnections, and finally even before and after the first die. The frequency of occurrence of these disconnections increases as the drawing speed increases, and the disconnection becomes easier as the number of dies to be drawn increases, and the probability of occurrence increases as the wire diameter decreases. In addition, the location to be disconnected is not fixed, and the location to be disconnected cannot be arbitrarily set in advance.

  In addition, as described above, there is a method of using a photoelectric sensor to detect the disconnection during wire drawing and directly seeing the wire wire breakage, but the sensor sensitivity is not stabilized due to the metal wire swinging during wire drawing. Has the disadvantage of false detection. In addition, the method of detecting the rotation speed of the metal wire guide pulley is due to wear of the pulley bearing, etc., and it is necessary to replace the pulley periodically. Since the material of the pulley is resin or ceramic, it can rotate. It is necessary to attach a metal sticker to detect the number, and there are irregularities in the number of rotations due to how the stickers are attached and replaced, and it is necessary to correct the number of rotations for each replacement, and the setting is troublesome. Have

  Furthermore, since both methods use a single motor to drive a plurality of shafts by belt drive in either method, even if the disconnection is detected in high-speed wire drawing even after the disconnection is detected Since the capstan before and after the die can not be stopped instantaneously, each part continues to rotate for a while after the disconnection, resulting in chain disconnection at locations other than the first disconnection, resulting in disconnection during wire drawing. There is a disadvantage that the part does not fit in a certain part.

  In addition, these slip-type wire drawing machines draw metal wires having a diameter of 15 to 30 μm with 12 to 24 dies, so the work of passing the metal wires through the dies after disconnection requires a lot of time and skill. It is. It takes about 2 to 3 minutes for a metal wire to pass through a die, and as the number of dies increases, the time required for re-setting at the time of disconnection increases. Furthermore, if a metal wire gets entangled with the capstan, it takes time to remove the metal wire from the capstan or to clean the capstan. .

  The present invention has been made in order to solve such problems, and the object of the present invention is to disconnect before the first die due to secondary and tertiary disconnection caused when the metal wire is disconnected. In view of the shortcomings of the current wire drawing machine, even if the metal wire is drawn at a high speed or with a large number of dies, the wire breakage occurs before the final die, High-speed thin wire drawing equipment and high-speed thin wire drawing equipment that detect work breaks so that workability is improved by keeping the break at the first break and preventing secondary and tertiary breaks. Is to provide a method.

In order to achieve the above object, the high-speed thin wire drawing device of the present invention comprises a metal wire unwinding part, a slip-type capstan arranged before and after the die, a plurality of wire drawing dies, and a metal wire winding part. In order to control the speed at which the metal wire is sent out from the spool, an arm-type tension control mechanism is installed, and the metal wire slip type high-speed thin wire drawing is controlled so that the metal wire sending speed is controlled by the detected metal wire tension. In the wire device,
Using an independent servo motor as the metal wire unwinding part motor, the capstan drive motor placed on the front side of the die, the capstan drive motor placed on the rear side of the die, and the winding part motor of the metal wire, While stopping is synchronized,
The upper limit value and lower limit value for stopping the device at high speed can be set arbitrarily for each tension during acceleration and constant speed, and the tension is outside the range of the upper limit value and lower limit value set as these set values. Sometimes each rotating part of the device is stopped at high speed instantly or in any order .

  According to another aspect of the present invention, in addition to the above-described invention, the capstan wire speed before and after the die is made higher than the speed of the metal wire to be drawn so that the metal wire slips at a constant rate with respect to the capstan. At the same time, the drive rotation speed fluctuation of each capstan before and after the die is suppressed to less than 0.1%.

  In another aspect of the present invention, the capstan drive is stopped at high speed within 0.5 seconds from the constant speed rotation state to the stop state.

  According to still another aspect of the present invention, in addition to the above-described invention, the capstan has a cylindrical shape or a cone shape, and the thin metal wire is a gold bonding wire.

Further, the disconnection detecting method of the high-speed thin wire drawing device of the present invention includes a metal wire unwinding portion, a slip capstan disposed before and after the die, a plurality of wire drawing dies, and a metal wire winding portion , respectively. Start and stop the machine by using independent servo motors as the unwinding part motor, the capstan drive motor placed on the front side of the die, the capstan drive motor placed on the back side of the die and the winding part motor of the metal wire. Configured to do so synchronously ,
An arm-type tension control mechanism is installed to control the speed at which the metal wire is sent out from the spool, and the metal wire is provided by a slip-type high-speed thin wire drawing device that controls the metal wire sending speed by the detected tension of the metal wire. When drawing the wire, the upper limit and lower limit values for stopping the device at high speed are determined for each tension at acceleration and constant speed, and the tension is outside the range of the upper limit and lower limit values set as these set values. At that time, the apparatus is stopped at high speed because the metal wire is disconnected.

  And, in another aspect of the present invention, in addition to the above-described invention, upper and lower limit set values for setting an upper limit value and a lower limit value with reference to the tension control value for each of acceleration and constant speed are The control value is ± 10%, and at constant speed, it is ± 5% of the control value.

  According to the disconnection detection method of the high-speed thin wire drawing device and the high-speed thin wire drawing device of the present invention, it is possible to set an upper limit value and a lower limit value for stopping the device at high speed for each tension at the time of acceleration and constant speed, respectively. When the tension is out of the range of these set values, the apparatus is stopped at a high speed on the assumption that the metal wire is disconnected, so that the disconnection can be reliably detected. In addition, the drive motor of each rotating part is an independent servo motor, and these are integrated and controlled in synchronization, so that each rotating part can be stopped instantaneously and in any order when disconnection is detected. As a result, the disconnection can be kept at one place, and the disconnection can be arbitrarily selected.

Embodiments of the present invention will be described with reference to the examples shown in FIGS.
The high-speed thin wire drawing device of the present invention includes a metal wire unwinding section 1, a tension control mechanism 2, a slip-type cylindrical capstan 4a installed on the front side of the die, and a slip-type cylindrical cap installed on the rear side of the die. It is comprised from the stun 4b, the die | dye 5, and the winding-up part 6 of the metal wire after wire drawing, In these structures, it is the same as a conventionally well-known thing.

  The metal wire unwinding unit 1 is driven by a motor 8a, and the metal wire winding unit 6 is driven by a motor 8b. The cylindrical capstan 4a installed on the front side of the die for drawing the metal wire is driven by a motor 8c, and the cylindrical capstan 4b installed on the rear side of the die is driven by an independent servo motor by a motor 8d. It has become. Controls such as starting and stopping of the servomotors 8a, 8b, 8c, and 8d that drive these are integrated. In this embodiment, the capstans 4a and 4b are cylindrical. However, the capstans 4a and 4b may have a cone shape as shown in the conventional example of FIG.

  The rotation speed of each motor is controlled so that the speed fluctuation of the rotating shaft portion is 0.1% or less in the acceleration state and the constant speed state, respectively. In addition, a function is provided in which the rotational speed of each capstan can be freely set according to the reduction of the dies, the wire diameter, and the number of dies. The arm-type tension control mechanism 2 attaches a strain gauge to the sensing part of the tension arm, takes out an analog signal from the tension meter, and controls the metal wire feed speed while measuring the tension of the metal wire. In addition, as a method of measuring the tension of the metal wire, a method of measuring the tension with a well-known arm-type tension control mechanism can be adopted, and in addition to using the strain gauge, tension using a potentiometer or load cell is used. May be detected.

  For the tension of the metal wire, the upper limit value and the lower limit value are set for the control value for each of acceleration and constant speed, and the disconnection occurs when the tension is detected outside the range of these upper and lower limits. Judging mechanically, the motor is automatically stopped at high speed. For example, an upper limit lower limit of ± 10% is set for the control value when accelerating, and ± 5% is set for the constant speed, and a disconnection occurs when the tension is detected outside the upper and lower limits. The motor is automatically stopped based on this determination. Further, the stop accuracy is forcibly braked by a brake or the like so that the time until the shaft rotation speed is stopped at 0 rpm from the rotation number of 3,000 to 4,000 rpm is within 0.5 seconds.

In the apparatus of the present invention, each die reduction is in the range of 4 to 10%, the final wire diameter is 20 to 25 μm, the number of dies is 10 to 24, and the wire speed is 200 to 400 m / min. In this case, the capstan drive speed on the front side of the die was drawn at a drawing speed of 0 to 3% of the drawing speed, and the disconnection position when the wire was disconnected was confirmed.
The tension setting (control value) is set to 10 g, the upper limit value and lower limit value of the tension part are set to 9 g when the wire drawing speed is accelerated, and 11 g (± 10% of the control value) when the wire drawing speed is accelerated. Set the lower limit to 9.5 g and the upper limit to 10.5 g (± 5% with respect to the control value), and when the upper and lower limit range was exceeded, the device was stopped at high speed because disconnection occurred. As a result, even if the disconnection occurred, all the disconnections were accommodated in the disconnection on the front side of the last four dies, and the apparatus could be stopped without disconnection in the first die.

  By using the tension detected by the arm type tension control mechanism, it is possible to detect disconnection at the time of wire drawing, so it can also be used for a conventional wire drawing device, and the upper and lower limit values are set appropriately. By setting, it can be applied to drawing of various wire diameters of various materials. In addition, by making all the drive motors independent, it becomes possible to stop the rotating part instantaneously after detecting the disconnection, and the recovery work after the disconnection is simplified, so the range of use is widened.

It is a front view which shows the concept of the slip-type high-speed thin wire drawing apparatus of this invention. It is a top view of FIG. A photoelectric sensor provided for conventional disconnection detection is a front view showing the concept of a slipping fast fine wire drawing apparatus that performs driving of the capstan before and after the die by a single motor over. FIG. 4 is a plan view of FIG. 3.

DESCRIPTION OF SYMBOLS 1 Metal wire unwinding part 1a Metal wire 2 Tension control mechanism 3 Metal wire guide pulley 4A Slip-type cone-shaped capstan (front side of die)
4B Slip-type cone-shaped capstan (after die)
4a Slip type cylindrical capstan (front side of die)
4b Slip type cylindrical capstan (after die)
5 Die 6 Metal wire winding part 7 Photoelectric sensor 8A, 8B, 8C, 8a, 8b, 8c, 8d for disconnection detection Motor 9 Belt 10 Lubricant shower nozzle 11 Wire drawing tank

Claims (6)

It consists of a metal wire unwinding part, a slip-type capstan placed before and after the die, a plurality of wire drawing dies and a metal wire winding part, and an arm-type tension control to control the speed at which the metal wire is fed from the spool. In the slip-type high-speed thin wire drawing device for metal wire, where the mechanism is installed and the metal wire feed speed is controlled by the detected tension of the metal wire,
Using an independent servo motor as the metal wire unwinding part motor, the capstan drive motor placed on the front side of the die, the capstan drive motor placed on the rear side of the die, and the winding part motor of the metal wire, While stopping is synchronized,
The upper limit value and lower limit value for stopping the device at high speed can be set arbitrarily for each tension during acceleration and constant speed, and the tension is outside the range of the upper limit value and lower limit value set as these set values. A high-speed thin wire drawing apparatus characterized in that sometimes each rotating part of the apparatus stops at high speed instantaneously or in any order . The capstan wire speed before and after the die is made faster than the speed of the metal wire to be drawn, and the metal wire slips at a constant rate with respect to the capstan, and the speed fluctuation of each drive rotation of the capstan before and after the die The high-speed thin wire drawing apparatus according to claim 1 , wherein the wire is pressed to less than 0.1%. The high-speed thin wire drawing apparatus according to claim 1 , wherein the capstan drive is stopped at a high speed within 0.5 seconds from a constant speed rotation state to a stop state. The high-speed thin wire drawing apparatus according to any one of claims 1 to 3 , wherein the capstan has a cylindrical shape or a cone shape, and the thin metal wire is a gold bonding wire. Metal wire unwinding part, slip type capstan arranged before and after the die, multiple wire drawing dies and metal wire winding part are respectively the metal wire unwinding part motor, capstan drive motor arranged on the front side of the die, The capstan drive motor placed on the back side of the die and the take-up motor of the metal wire are used as independent servo motors, and is configured to synchronize the start and stop of the device ,
An arm-type tension control mechanism is installed to control the speed at which the metal wire is sent out from the spool, and the metal wire is provided by a slip-type high-speed thin wire drawing device that controls the metal wire sending speed by the detected tension of the metal wire. When drawing the wire, the upper limit and lower limit values for stopping the device at high speed are determined for each tension at acceleration and constant speed, and the tension is outside the range of the upper limit and lower limit values set as these set values. A disconnection detection method for a high-speed thin wire drawing apparatus, wherein the apparatus is stopped at a high speed as if the metal wire was disconnected. The upper and lower limits of the tension set by the upper and lower limits based on the tension control values at acceleration and constant speed are set to ± 10% of the control value at acceleration, and the control values at constant speed. breaking detection method for high-speed fine wire drawing device according to claim 5 in which the ± 5% of.

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