JP4536896B2 - Hoop frame tension control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention particularly relates to a tension control method for a hoop-shaped frame for controlling the tension of a hoop-shaped lead frame.
[0002]
[Prior art]
Conventionally, what is shown in FIG. 1 is known as a resin molding apparatus.
Reference numeral 1 in the figure denotes an apparatus main body having a lower fixing plate 2 at the bottom. A tie bar 3 is erected on the lower fixing plate 2, and an upper fixing plate 4 is attached to the upper portion thereof. The tie bar 3 is provided with a movable plate 5 that can move up and down. A lower mold 6 and a lower chase 7 are provided on the upper surface side of the moving plate 5. An upper die 8 and an upper chase 9 are provided on the lower surface side of the upper fixing plate 4.
[0003]
A tension roller unit 11 having a tension roller 10 and a feed roller unit 13 having a feed roller 12 are arranged before and after the apparatus main body 1, respectively. Here, the tension roller 10 is operated by a torque motor, and the feed roller 12 is operated by a servo motor. A hoop-shaped lead frame 14 is laid over the tension roller 10 and the feed roller 12. Here, the feed roller 12 is provided with teeth (not shown) to be inserted into the feed holes of the lead frame 14. Below the tension roller unit 11 and the feed roller unit 13, a tension roller lifter unit 15 and a feed roller lifter unit 16 for moving these units up and down are provided.
[0004]
By the way, in the resin molding apparatus having such a configuration, the tension roller 10 is controlled by a torque motor, and its circuit is as shown in FIG. Note that reference numeral 17 in FIG. 2 denotes a torque motor. In general, when the relay Ry1 (tension) is OFF as in the initial state of FIG. 3A, the motor torque is zero as shown in FIG. Further, when Ry1 is ON and the winding resistance of the motor is Rm, the applied voltage Vm to the torque motor 17 is Vm = 100 × Rm / (Rm + R1). If R1 = 3Ω and Rm = 5Ω, Vm is about 63V, and a strong torque during normal operation is generated at once.
[0005]
Next, the operation of the resin molding apparatus having such a configuration will be described.
First, with the teeth of the feed roller 12 entering the feed hole of the lead frame 14, the rollers 10 and 12 rotate to convey the lead frame 14 to a fixed position. After the conveyance, the feed roller 12 holds the stop position, and the tension roller 10 generates a rotational force in the left direction in the drawing to apply a tension force to the lead frame 14 so that the lead frame 14 is stretched smoothly. Here, the lead frame 14 conveyed onto the mold is moved downward by the downward movement of the roller unit by the tension roller unit 11 and the feed roller unit 13 and set on a lead frame receiver (not shown). Then, positioning is performed so that a guide post (not shown) of the upper die 8 is guided by a guide hole (not shown) of the lower die 6, and the lower chase 7 and the upper chase 9 are fitted to each other. After the resin tablet supplied in (not shown) is heated and melted, the plunger (not shown) is pushed up. Then, the molten resin in the pot is pressurized and supplied from the runner groove through the gate to the lower cavity and the upper cavity to seal the semiconductor element. The molded package is released from the mold surface by the ejector pins, moved upward by the upward movement of the tension roller unit 11 and the feed roller unit 13, and conveyed again by the rotation of the tension roller 10 and the feed roller 12.
[0006]
[Problems to be solved by the invention]
By the way, in the conventional resin molding apparatus, when the tension is turned on in a state in which the lead frame 14 has a slack, the tension roller 10 rotates until the slack in the lead frame 14 disappears, and the slack disappears and the lead frame 14 is stretched. A force due to the torque of the tension roller 10 and the inertial force of the tension roller 10 is impacted on the feed hole of the lead frame. Therefore, there is a problem that the feed hole of the lead frame 14 is deformed or the wire on the lead frame 14 is broken by the vibration.
[0007]
The first invention of the present application has been made in consideration of such circumstances, and by preventing the deformation of the lead frame feed hole and the vibration of the lead frame by increasing the torque when applying the tension linearly or stepwise, An object of the present invention is to provide a tension control method for a hoop-shaped frame.
[0008]
In the second invention of the present application, the applied torque is increased linearly or stepwise according to the decrease in the speed of the tension roller, and the predetermined torque is applied after the tension roller is stopped. It is an object of the present invention to provide a tension control method for a hoop-shaped frame that can prevent deformation of the feed hole of the frame and vibration of the lead frame.
[0009]
The third invention of the present application increases the rotational speed limit value linearly or stepwise in response to a decrease in the tension roller speed, and after determining whether the tension roller is stopped, sets the rotational speed limit value to a predetermined rotational speed limit value . It is an object of the present invention to provide a hoop-shaped frame tension control method capable of preventing deformation of a feed hole and vibration of a lead frame.
[0010]
[Means for Solving the Problems]
According to a first aspect of the present invention, a tension is applied in a method for controlling the tension of a hoop-like lead frame that is stretched between a tension roller and a feed roller that are respectively driven by a motor and is resin-sealed at a predetermined position by a mold. This is a tension control method for a hoop-like frame, wherein the torque at the time is increased linearly or stepwise.
[0011]
A second invention of the present application is a method for controlling the tension of a hoop-shaped lead frame that is stretched between a tension roller and a feed roller that are respectively driven by a motor and is resin-sealed at a predetermined position by a mold . The hoop-shaped frame tension control method is characterized in that the applied torque is increased linearly or stepwise in response to a decrease in speed, and a predetermined torque is applied after the stoppage of the tension roller is determined .
[0012]
A third invention of the present application is a method for controlling the tension of a hoop-shaped lead frame that is stretched between a tension roller and a feed roller that are respectively driven by a motor and is resin-sealed at a predetermined position by a mold . The hoop-shaped frame tension control method is characterized in that a rotational speed limit value is increased linearly or stepwise in response to a decrease in speed, and a predetermined rotational speed limit value is determined after determination of tension roller stoppage .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
In the first invention, linearly changing the torque at the time of applying tension means, for example, as shown in FIG. 7 to be described later, that the firing angle is changed from π to the firing angle required to generate a predetermined torque with time. By changing, it means that the effective voltage related to the torque motor is gradually increased to increase the torque linearly. Further, changing the torque when applying the tension stepwise means increasing the torque stepwise using a plurality of relays or the like until reaching a certain value, for example, as shown in FIG. .
[0014]
In the second invention, in order to change the torque at the time of applying tension according to the movement of the tension roller, for example, as shown in FIG. 8 described later, phase control is performed so that the torque of the torque motor is reduced by a microcomputer. There is a method of performing phase control so that the torque of the torque motor becomes a specified torque after detecting the rotation stop of the tension motor by the rotation detector. Further, as shown in FIG. 11 described later, when a servo motor is used instead of the conventional torque motor, the servo motor is controlled to a low torque by issuing a torque command value so that the torque of the servo motor is reduced by a microcomputer. There is a method of detecting the rotation stop signal of the servo driver and controlling the torque command value so that the torque of the servo motor becomes a specified torque.
[0015]
In the third invention, in order to change the limit value of the rotation speed when applying tension according to the movement of the tension roller, for example, a servo motor is used instead of the torque motor, and as shown in FIG. The servo motor torque is controlled by the preset torque command value, and the rotation speed of the servo motor is limited according to the input speed limit command value. A method for outputting a rotation stop signal to the microcomputer is described below. In order to change the limit value of the rotational speed when applying tension and the torque when applying tension according to the movement of the tension roller, the torque of the servo motor is reduced from the microcomputer as shown in FIG. The torque command value is issued to control the servo motor to low torque, and the servo motor is controlled to low speed by issuing a speed limit command value that reduces the rotation speed of the servo motor. A method of outputting a stop signal to a microcomputer can be mentioned.
[0016]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. In addition, since the fundamental structural member of the resin molding apparatus is the same as that of FIG. 1 already mentioned, the same member attaches | subjects the same number and demonstrates.
[0017]
Example 1
The first embodiment is characterized in that the torque when applying tension is changed in stages. FIG. 4 is a circuit diagram for controlling the torque motor 17 according to the first embodiment. Numbers 21a, 21b, and 21c in the figure indicate relays Ry1, Ry2, and Ry3 having resistors R1, R2, and R3, respectively. 5A and 5B show the relationship between time, the state of each relay Ry, and the torque.
[0018]
In FIG. 4, when the relays 21a to 21c are OFF, the motor torque is zero. When only the relay 21a is ON and the winding resistance of the motor is Rm, the applied voltage Vm1 to the motor is Vm1 = 100 × Rm / (Rm + R1). When the relays 21b and 21c are ON, the voltage Vm2 applied to the motor is Vm2 = 100 × Rm / {Rm + R1 · R2 / (R1 + R2). Further, when all of the relays 21a to 21c are ON, the voltage Vm3 applied to the motor is Vm3 = 100 × Rm / {Rm + R1 · R2 · R3 / (R1 · R2 + R1 · R3 + R2 · R3)}.
[0019]
If R1 = R2 = R3 = 10Ω and Rm = 5Ω, Vm1 is about 33V, Vm2 = 50V, and Vm3 is about 60V, and the torque can be increased stepwise.
[0020]
According to the first embodiment, the torque at the time of applying the tension is changed stepwise using the relays 21a, 21b, and 21c, thereby preventing the lead frame feed hole deformation and the lead frame vibration. it can.
[0021]
(Example 2)
The second embodiment is characterized in that the torque when the tension is applied is linearly changed. FIG. 6 is a circuit diagram for controlling the torque motor 17 according to the second embodiment. In the figure, reference numeral 22 denotes a thyristor (SR1), and reference numerals 23 and 24 denote ignition circuits for starting the thyristor 22 by the microcomputer 25. FIGS. 7A and 7B show the relationship between time, firing angle, and torque, respectively. FIG. 8 is a waveform diagram for explaining the firing angle.
[0022]
According to the second embodiment, since the firing angle α of the thyristor 22 is controlled (phase control) by the microcomputer 25, the torque motor is changed by changing the firing angle α from π (rad) to 0 with time. The effective voltage applied to 17 increases accordingly, and the torque generated by the motor can be increased linearly with time. Therefore, according to the second embodiment, the same effect as the first embodiment can be obtained.
[0023]
Example 3
The third embodiment is characterized in that the torque at the time of applying the tension is changed according to the movement of the tension roller 10, and the torque is controlled by rotation feedback. FIG. 9 is a circuit diagram for controlling the torque motor 17 according to the third embodiment. Reference numeral 25 in the figure indicates a microcomputer for phase control and rotation detection, and reference numeral 26 indicates a rotation detector (TG) for detecting the rotation of the torque motor 17. This rotation detector 26 is electrically connected to the microcomputer 25. FIGS. 10A and 10B show the relationship between time, torque, and rotational speed, respectively. FIG. 11 is a block diagram showing a state from the start to the end of the phase control according to the circuit diagram.
[0024]
In the third embodiment, the microcomputer 25 that performs phase control of the power source of the torque motor 17 performs phase control so that the torque of the torque motor 17 is reduced when the tension is turned on, and the rotation detector 26 detects the rotation stop of the tension motor. Phase control is performed so that the torque of the torque motor 17 becomes a specified torque. At this time, the low torque value in the figure is the self-starting torque + α of the mechanical system of the tension motor.
[0025]
According to the third embodiment, the same effect as that of the first embodiment can be obtained because the torque when the tension is applied is detected by using the rotation detector 26 of the torque motor 17 and the torque when the tension is applied is changed according to the movement of the tension roller 10. .
[0026]
Example 4
The fourth embodiment is characterized in that the torque at the time of applying the tension is changed according to the movement of the tension roller 10, and the torque is controlled by rotation feedback. However, Example 4 shows a case where the tension roller 10 is driven by a servo motor.
[0027]
FIG. 12 is a circuit diagram for controlling the servo motor 27 according to the fourth embodiment. In the figure, reference numeral 27 denotes a servo motor (SM) for driving the tension roller 10, reference numeral 28 denotes an encoder, and reference numeral 29 denotes a servo driver (torque control) electrically connected to the microcomputer 25. Here, a torque command is sent from the microcomputer 25 to the servo driver 29, and conversely, a rotation stop signal is sent from the servo driver 29 to the microcomputer 25.
[0028]
FIGS. 13A and 13B show the relationship between time, torque command, and rotation speed, respectively. FIG. 14 is a block diagram showing a state from the start to the steady tension according to the circuit diagram.
[0029]
In the fourth embodiment, the servo driver 29 controls the torque of the servo motor 27 according to the input torque command value. Further, when the servo motor 27 is already below the set number of rotations, a rotation stop signal is output. The microcomputer 25 controls the servo motor 27 to a low torque by issuing a torque command value that reduces the torque of the servo motor 27 when the tension is ON, and when the rotation stop signal of the servo driver 29 is detected, the microcomputer 25 The torque command value is controlled so that the torque becomes the specified torque. At this time, the low torque value in FIG. 13A is the self-starting torque + α of the mechanical system of the tension motor 10.
[0030]
According to the fourth embodiment, the tension roller 10 is driven by the servo motor 27, and the torque when the tension is applied is changed according to the movement of the tension roller 10. Therefore, the same effect as the first embodiment can be obtained.
[0031]
(Example 5)
The fifth embodiment is characterized in that the limit value of the rotational speed at the time of applying tension is changed according to the movement of the tension roller, and the speed is controlled by rotational feedback. However, Example 5 shows a case where the tension roller 10 is driven by a servo motor.
[0032]
FIG. 15 is a circuit diagram for controlling the servo motor 27 according to the fifth embodiment. Here, the servo driver 29 has functions of torque control and speed control. That is, a constant torque command and a speed limit command value are input from the microcomputer 25 to the servo driver 29, and a rotation stop signal is sent from the servo driver 29 to the microcomputer 25.
[0033]
FIGS. 16A and 16B show the relationship between time, speed limit command value, and rotation speed, respectively. FIG. 17 is a block diagram showing a state from the start to the steady tension according to the circuit diagram.
[0034]
In the fifth embodiment, the servo driver 29 controls the torque of the servo motor 27 according to the input torque command value, and limits the rotation speed of the servo motor 27 according to the input speed limit command value. Further, a rotation stop signal is output when the rotation speed of the servo motor 27 is already equal to or lower than the set rotation speed. A fixed torque command value is inputted to the servo driver 29 so that the torque of the servo motor 27 becomes a prescribed torque. The microcomputer 25 controls the servo motor 27 to rotate at a low speed by issuing a speed limit command value that causes the rotation speed of the servo motor 27 to be small (10% of the normal time) when the tension is turned on. When the rotation stop signal is detected, the speed limit command value of the servo motor 27 is switched to the value during normal operation.
[0035]
According to the fifth embodiment, since the limit value of the rotation speed of the tension roller 10 when applying tension is changed according to the movement of the tension roller 10, the same effect as the first embodiment can be obtained.
[0036]
(Example 6)
The sixth embodiment is characterized in that the torque and rotational speed limit values when applying tension are changed in accordance with the movement of the tension roller, and the torque and speed are controlled by rotational feedback. However, Example 6 shows a case where the tension roller 10 is driven by a servo motor.
[0037]
FIG. 18 is a circuit diagram for controlling the servo motor 27 according to the sixth embodiment. In FIG. 18, the servo driver 29 has a function of performing torque control and speed control. Further, a speed limit command and a torque command are sent from the microcomputer 25 to the servo driver 29, and conversely, a rotation stop signal is sent from the servo driver 29 to the microcomputer 25.
[0038]
19A and 19B show the relationship between time, torque command value, speed limit command value, and rotation speed, respectively. FIG. 20 is a block diagram showing a state from the start to the steady tension according to the circuit diagram.
[0039]
In the sixth embodiment, the servo driver 29 controls the torque of the servo motor 27 according to the input torque command value, and limits the rotation speed of the servo motor 27 according to the input speed limit command value. Further, a rotation stop signal is output when the rotation speed of the servo motor 27 is already equal to or lower than the set rotation speed. The microcomputer 25 controls the servo motor 27 to a low torque by issuing a torque command value that reduces the torque of the servo motor 27 when the tension is ON, and the rotation speed of the servo motor 27 is small (normal time). 10%), the servo motor 27 is controlled to rotate at a low speed. When the rotation stop signal of the servo driver 29 is detected, the speed limit command value and the torque command value of the servo motor 27 are switched to values during normal operation.
[0040]
According to the sixth embodiment, since the limit value of the torque and the rotation speed when applying tension is changed according to the movement of the tension roller, the same effect as in the first embodiment can be obtained.
[0041]
【The invention's effect】
As described above in detail, according to the present invention, the tension of the hoop-like frame that can prevent the deformation of the lead frame feed hole and the vibration of the lead frame by increasing the torque when applying the tension linearly or stepwise. A control method can be provided.
Further, according to the present invention, the torque at the time of applying the tension is increased linearly or stepwise according to the decrease in the speed of the tension roller, and after the stoppage of the tension roller is determined, the predetermined torque is applied . A hoop-shaped frame tension control method having the same effect as described above can be provided.
Further, according to the present invention, the rotational speed limit value is increased linearly or stepwise according to the decrease in the tension roller speed, and after the tension roller stop determination, the predetermined rotational speed limit value is set. A tension control method for the hoop-like frame having the same effect can be provided.
[Brief description of the drawings]
FIG. 1 is an overall view of a resin molding apparatus.
FIG. 2 is a circuit diagram of a torque motor used for driving a tension roller, which is one configuration of a conventional resin molding apparatus.
FIG. 3 is a characteristic diagram showing the relationship between time, relay state, and torque in the torque motor of FIG. 2;
FIG. 4 is a circuit diagram of a torque motor used for driving a tension roller which is one configuration of the resin molding apparatus according to Embodiment 1 of the present invention.
FIG. 5 is a characteristic diagram showing the relationship between time, relay state, and torque in the torque motor of FIG. 4;
FIG. 6 is a circuit diagram of a torque motor used for driving a tension roller which is one configuration of a resin molding apparatus according to Embodiment 2 of the present invention.
7 is a characteristic diagram showing the relationship between time, firing angle, and torque in the torque motor of FIG. 6. FIG.
FIG. 8 is a waveform diagram for setting the firing angle in FIG.
FIG. 9 is a circuit diagram of a torque motor used for driving a tension roller which is one configuration of a resin molding apparatus according to Embodiment 3 of the present invention.
10 is a characteristic diagram showing the relationship between time, torque, and rotation speed in the torque motor of FIG. 9. FIG.
11 is a block diagram for explaining the operation from the start to the end in the torque motor of FIG. 9;
FIG. 12 is a circuit diagram of a servo motor used for driving a tension roller which is one configuration of a resin molding apparatus according to Embodiment 4 of the present invention.
13 is a characteristic diagram showing the relationship between time, torque command, and rotation speed in the servo motor of FIG.
14 is a block diagram for explaining the operation from the start to the end in the servo motor of FIG. 12. FIG.
FIG. 15 is a circuit diagram of a servo motor used for driving a tension roller, which is a configuration of a resin molding apparatus according to Embodiment 5 of the present invention.
16 is a characteristic diagram showing the relationship between time, speed limit command, and rotation speed in the servo motor of FIG. 15;
17 is a block diagram for explaining the operation from the start to the end in the servo motor of FIG. 15;
FIG. 18 is a circuit diagram of a servo motor used for driving a tension roller, which is one configuration of a resin molding apparatus according to Embodiment 6 of the present invention.
19 is a characteristic diagram showing the relationship between time, torque command, speed limit command, and rotation speed in the servo motor of FIG. 18;
20 is a block diagram for explaining the operation from the start to the end in the servo motor of FIG. 18;
[Explanation of symbols]
1 ... the device body,
2 ... Lower fixing plate,
3 ... Tie bar,
4 ... Upper fixing plate,
5 ... Moving plate,
6 ... Lower mold,
7 ... Lower chase,
8 ... Upper mold,
9 ... Upper chase,
10 ... tension roller,
11 ... tension roller unit,
12 ... feed roller,
13 ... feed roller unit,
14 ... Lead frame,
15 ... tension roller lifter unit,
16: Feed roller lifter unit,
17 ... torque motor,
21a-21c ... relay,
23, 24 ... ignition circuit,
25 ... Microcomputer,
26: Rotation detector,
27 ... Servo motor,
28 ... Encoder,
29 ... Servo driver.

Claims (3)

In a method for controlling the tension of a hoop-shaped lead frame that is straddled between a tension roller and a feed roller that are respectively driven by a motor, and is resin-sealed at a predetermined position by a mold,
A tension control method for a hoop-like frame, wherein the torque when applying tension is increased linearly or stepwise. In a method for controlling the tension of a hoop-shaped lead frame that is straddled between a tension roller and a feed roller that are respectively driven by a motor, and is resin-sealed at a predetermined position by a mold,
A tension control method for a hoop-shaped frame, wherein the applied torque is increased linearly or stepwise in accordance with a decrease in the speed of the tension roller, and a predetermined torque is applied after determining the stop of the tension roller . In a method for controlling the tension of a hoop-shaped lead frame that is straddled between a tension roller and a feed roller that are respectively driven by a motor, and is resin-sealed at a predetermined position by a mold,
A tension control method for a hoop-like frame, wherein a limit value of a rotational speed is increased linearly or stepwise in accordance with a decrease in the speed of the tension roller, and a predetermined rotational speed limit value is set after determining the stop of the tension roller .

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