JP2004181461A - Pressurizing device and pressurizing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressurizing device for producing pressuring-worked products without defect by reducing damage to a workpiece while preventing overshoot by performing the torque control of a servomotor from the start to the end of pressurization when pressurizing the workpiece, and a pressurizing method therefor. <P>SOLUTION: When the device is switched to a torque control mode, the workpiece is pressurized with large torque gain for a specified time (T1) and, after that, pressurized for a specified time (T2) by switching the device to small torque gain. During this time, a pressurizing force becomes a set pressurizing force (PR1). By increasing the torque gain in the process where the pressurizing force reaches the set pressurizing force (PR1) from the start of the pressurization like this, the overshoot of pressure is prevented and the damage to the work piece is reduced. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pressurizing apparatus and a pressurizing method using a servomotor for press-working a workpiece.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in pressure processing of a work piece, for example, in a pressing device of a bonding device for pressing an IC chip on a substrate, an air cylinder for vertical sliding installed on an upper portion of the device frame 1 as shown in FIG. 25, a pressurizing air cylinder 26 incorporating a pressurizing head 27 for pressurizing is provided so as to be driven by the vertical movement of the vertical sliding air cylinder 25. After being lowered to the position for applying pressure to the work piece 2, the workpiece is pressurized by the pressurizing air cylinder 26.
[0003]
In this case, an electropneumatic regulator 29 which receives a command from a controller 28 is connected to the pressurizing air cylinder 26, and the pressure applied from the controller 28 is set to the electropneumatic regulator 29 with an analog voltage value 30. The working pressure (factory pressure) 31, which is the original pressure, is pressure-controlled to the pressurizing force 32 set to the analog voltage, and is sent to the pressurizing air cylinder 26 so as to be pressurized.
In some cases, the pressurizing head may be moved up and down by replacing the above-described vertical slide air cylinder with a servomotor.
[0004]
In a pressurizing system using such a pressurizing air cylinder or electropneumatic regulator, an error occurs between the set pressing force value and the actual pressing force on the work piece due to poor operation accuracy between them, resulting in defective products. There was a problem of getting out.
[0005]
Therefore, a pressurizing device using a servomotor without a pressurizing air cylinder or an electropneumatic regulator has been proposed. (For example, refer to Patent Document 1).
[0006]
This is based on the drive current value control of the servomotor, and the above-mentioned problem is solved because the servomotor is controlled by detecting the applied pressure and feeding back the detected pressure amount.
[0007]
Further, the pressure is controlled so as to switch from high speed to low speed just before the lower end surface of the pressing tool (corresponding to the pressing head 27) comes into contact with the upper end surface of the component (corresponding to the work piece 2). , The pressure applied to the parts is controlled to be constant.
[0008]
In this case, since the lower end face of the pressing tool is controlled to switch from high speed to low speed just before contacting the upper end face of the component, the impact force when the pressing tool contacts the component is reduced.
[Patent Document 1]
JP 2001-71196 A (page 6, paragraphs 0049 to 0055).
[0009]
[Problems to be solved by the invention]
However, since the drive current is controlled at a constant speed even though the speed is low until the set pressure (target voltage) is reached, excessive pressurization of parts, so-called overshoot, may cause defects such as cracks. There is a problem that damage to parts is large.
[0010]
In view of the above, an object of the present invention is to prevent overshoot by performing torque control of a servomotor by switching a torque gain from the start to the end of pressure and following a set pressing force during pressure processing of a workpiece. Accordingly, an object of the present invention is to provide a pressurizing apparatus and a pressurizing method for reducing the damage to a workpiece and producing a press-processed product having no defect.
[0011]
[Means for Solving the Problems]
A pressurizing device for controlling the servomotor control mode in the order of a first position control mode, a torque control mode, and a second position control mode during pressurization of a workpiece; However, when the pressure processing operation is started, pressure is applied with a large torque gain for a predetermined time, and thereafter, the pressure is switched to a small torque gain.
[0012]
Further, when the workpiece is pressurized, a pressurizing method is performed in which the control mode of the servomotor is switched in the order of a first position control mode, a torque control mode, and a second position control mode. When the pressure processing operation is started, pressure is applied with a large torque gain for a predetermined time, and thereafter, the pressure is switched to a small torque gain.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a schematic configuration diagram showing an embodiment of the pressurizing device, and shows a pressurizing standby position of the pressurizing head 6. FIG. 2 shows a state in which the pressure head 6 is lowered from the standby position in FIG. 1 to the pressure start position.
[0014]
The pressurizing device according to this embodiment is used, for example, in a bonding device that presses an IC chip onto a substrate. The servomotor 3 converts the rotational motion of the servomotor 3 into a linear motion and moves up and down. The lifting unit 4 is connected to the upper part of the gate-shaped apparatus frame 1. A holder 20 is mounted below the elevating unit 4, and a pressure detector 5 having an elastic alloy 21 is sandwiched between the holder 20 and the pressure detector 5 has a pressure head for pressure processing. 6 is erected.
[0015]
Then, as shown in FIG. 2, the pressurizing head 6 descends with the lowering of the elevating unit 4 due to the rotation of the servomotor 3, and the work piece 2 placed on the lower part of the apparatus frame 1 is press-worked. It has become.
[0016]
The lifting unit 4 has a ball screw mechanism (not shown) including a nut and a screw shaft that moves up and down via a steel ball. The pressure detector 5 has a structure in which the elastic alloy 21 is loaded (pressurized). This is a strain gauge type in which a minute displacement when deformed due to the application of the head 6 is output as an output voltage to measure a pressing force applied to the work piece 2, and all of them are conventional.
[0017]
The servomotor 3 is connected to a servomotor controller 8 which is connected to a host controller 7 which is a command system and performs overall control of the servomotor. The pressure detector 5 sends a pressure signal to the workpiece 2 from the pressure detector 5. Feedback is fed back to the servo motor controller 8 via the pressure detector amplifier 9.
[0018]
The servo motor controller 8 creates a pressurization control table 11, which will be described later, and compares the pressurized force value corresponding to the pressure control table 11 with the detected pressure value from the pressure detector, and the difference between the signal matcher 14 and the signal matcher 14. Has a pressure control controller 15 for torque-controlling the pressure value.
[0019]
Next, a pressurizing method in the pressurizing apparatus of the present invention will be described based on a block diagram of FIG. 3 showing a control system and a time chart of FIG. 4 showing a relationship between a pressing force and time.
[0020]
First, a pressurization setting parameter 10 in which a pressurization control program for the work piece 2 is set is transmitted from the host controller 7 and input to the servo motor controller 8, and the servo motor controller 8 controls the pressurization based on the parameter 10. Table 11 is created. Therefore, the pressure processing operation (first position control mode, torque control mode, second position control mode) described below is performed according to the pressure control table 11.
[0021]
(First position control mode)
The host controller 7 outputs a command pulse 12 for lowering the pressure head 6 from the pressure standby position to the pressure start position, and the servo motor controller 8 rotates the servo motor 3 to lower the pressure head 6 and start pressurization. When the position is reached, a pressurization start command 13 is issued from the upper controller 7 to the servo motor controller 8. (See diagram a in FIGS. 2 and 4).
[0022]
Then, the pressurizing operation in-progress signal 19 is output from the servo motor controller 8 to the host controller 7, and it is recognized that the pressurizing operation is being performed. At the same time, the servo motor 3 rotates at a low speed, and the pressure head 6 approaches the workpiece 2 from the pressure start position. (See diagram b in FIG. 4).
[0023]
Then, when the pressure head 6 comes into contact with the workpiece 2 and the pressure detector 5 detects the applied pressure (PR0), the servo motor controller 8 switches from the first position control mode to the torque control mode according to the pressure signal.
[0024]
(Torque control mode)
At the same time as switching to the torque control mode, pressurization is started with a large torque gain set in advance in the pressure control controller 15 of the servo motor controller 8 and pressurized for a predetermined time (T1). Thereafter, the torque is switched to a small torque gain and the pressure is increased for a predetermined time (T2). During this time, the pressure becomes the set pressure (PR1).
[0025]
The pressurizing time (T1) at a large torque gain is variable with respect to the pressurizing time (T0) until the detection value of the pressure detector 5 reaches the set pressing force (PR1) value. .35T0 is preferred, but 1.25T0 is optimal. The pressure (PR0) at the start of pressurization may be selected from a range of 0.3 to 0.9 times the set pressure (PR1).
[0026]
The torque gain is a rate at which the torque is changed. Since the torque gain is sensitive to a minute change in the pressing force detected when the torque gain is large, the torque gain is excellent in following up the change in the pressing force, and the torque control is also prompt. It can be carried out. Therefore, in the case of the present invention, by increasing the torque gain in the process of reaching the set pressure (PR1) from the start of pressurization, pressure overshoot can be prevented, and damage to the workpiece can be reduced. The numerical value of the torque gain may be, for example, about 2 rad / sec and about 0.5 rad / sec for the applied pressure of 1 kgf.
[0027]
Here, an example of the torque control mode in the light pressure bonding process will be described with reference to the time chart of FIG. First, after 0.5 seconds (T0) from the pressure (PR0) of 0.025 Kgf at the start of pressurization, the pressure (PR1) reaches 0.05 Kgf, and the pressure is increased in a state where a large torque gain is applied from the start of pressurization. Pressurization is performed for 625 seconds (T1), and thereafter, the torque is switched to a small torque gain, and pressurization is performed for another 2 seconds (T2). As a result, good bonding processing results are obtained.
[0028]
The operation in the above torque control mode is in accordance with the pressurization control table 11 created in the servo motor controller 8, and the pressure command value 16 corresponding to the pressurization setting parameter 10 is determined in the pressurization control table 11, The command value 16 is matched with the pressure detection value 17 detected by the pressure detector 5 by the signal matching unit 14, and the difference is input to the pressure control controller 15, and the pressure detection value 17 and the pressure command value are input from the pressure control controller 15. A torque command 18 that gives a pressing force as close as possible to 16 is issued to the servomotor 3, and the servomotor 3 is torque-controlled.
[0029]
(Second position control mode)
When the pressurization with a small torque gain (time T2) is completed in the torque control mode, the servo motor controller 8 switches from the torque control mode to the second position control mode at the same time as releasing the pressurization to the workpiece.
[0030]
When the mode is switched to the second position control mode, the rotation of the servomotor 3 raises the pressure head 6 to the pressure start position (the diagram c in FIGS. 2 and 4), and when the pressure head 6 rises, the servomotor controller 8 moves to the upper position. The pressurizing operation signal 19 output to the controller 7 is turned off, and the recognition that the pressurizing operation is being performed is released. After confirming this, the pressurization start command 13 issued from the host controller 7 is cut off.
[0031]
Thereafter, a command pulse 12 for raising the pressurizing head 6 from the pressurizing start position to the pressurizing standby position is output from the host controller 7 to the servomotor 3. Then, the pressurizing head 6 is raised by the rotation of the servomotor 3 and returns to the pressurizing standby position (the diagram d in FIGS. 1 and 4).
[0032]
【The invention's effect】
According to the pressurizing apparatus and pressurizing method of the present invention, when pressurizing a workpiece, the pressurizing operation is performed for a predetermined time during a pressurizing operation on a workpiece, and then the torque control of the servomotor is performed with a large torque gain for a predetermined time. Since the pressure is switched and pressed, overshooting of the pressure can be prevented, and damage to the workpiece can be reduced, so that a high-quality press-processed product without defects can be produced.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of a pressing device according to the present invention, and shows a pressing standby position of a pressing head.
FIG. 2 is a view showing a state in which the pressure head of FIG. 1 is lowered from a standby position to a pressure start position.
FIG. 3 is a block diagram showing a control system of the present invention.
FIG. 4 is a time chart showing a relationship between a pressing force and time.
FIG. 5 is a schematic configuration diagram of a conventional pressure device.
[Explanation of symbols]
1. 1. Device frame Workpiece3. Servo motor4. Elevating part 5. Pressure detector6. Pressure head 7. Upper controller 8. 10. Servo motor controller Pressurization setting parameter Pressurization control table

Claims (4)

A pressurizing head for pressurizing processing is assembled to an elevating unit that converts the rotational motion of a servo motor provided in the device frame into a linear motion and moves up and down. A pressurizing apparatus for pressurizing the workpiece, by switching the control mode of the servomotor in the order of a first position control mode, a torque control mode, and a second position control mode when the workpiece is pressurized. Pressurizing device characterized by performing. 2. The torque control mode according to claim 1, wherein when the pressurizing head enters a pressurizing operation on the workpiece, pressurizing is performed with a large torque gain for a predetermined time, and thereafter, the pressure is switched to a small torque gain. Pressurizing device. A pressurizing head for pressurizing processing is assembled to an elevating unit that converts the rotational motion of a servo motor provided in the device frame into a linear motion and moves up and down. A pressurizing method for pressurizing the work piece, by switching the control mode of the servomotor in the order of a first position control mode, a torque control mode, and a second position control mode when the work piece is pressurized. Pressurization method to be performed. The torque control mode of the servo motor according to claim 3, wherein when the workpiece of the pressure head enters a pressure processing operation, pressure is applied with a large torque gain for a predetermined time, and thereafter, pressure is switched to a small torque gain. Pressurization method.

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