JP2003031619A - Bonding apparatus and bonding method - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a bonding apparatus and a bonding method capable of switching a control mode in a bonding operation at a high speed. A Z-axis motor (6a) for driving a bonding tool in a bonding apparatus that presses a chip to a substrate while applying a load to a chip by the bonding tool.
A control unit 18 as an upper control unit, a lower control unit 20 for transmitting and receiving signals, a storage unit 21 for storing data such as programs and control variables, and a detection function for detecting the position and speed of a bonding tool. When the lower control unit 20 controls the Z-axis motor 6a via the current control unit 26, the lower control unit 20 stores the program data stored in the storage unit 21. The control is performed by switching between a first control mode in which control is performed based on the first control mode and a second control mode in which control is performed based on a command from the control unit 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding apparatus and a bonding method for bonding an electronic component such as a flip chip to a surface to be bonded.

[0002]

2. Description of the Related Art As a method of mounting an electronic component such as a flip chip on a substrate, a bonding method such as ultrasonic bonding or thermocompression bonding is known. In this bonding, the bumps of the flip chip are bonded to the electrodes of the substrate by pressing the electronic component against the substrate with a predetermined load using a bonding tool. The bonding tool used for pressing generally has a function of attracting and holding the flip chip in many cases, and in the bonding operation, the bonding tool holding the flip chip is lowered in the process of lowering the bonding tool. By controlling the operation, the pressing load of the bump against the electrode on the substrate is controlled. The operation control of this bonding tool is generally performed by using the position control function and torque control function of the servo motor that drives the ascending / descending operation of the bonding tool. The control mode is switched to the load control mode.

By the way, to control the operation of the servo motor,
A driver that supplies drive power to the servo motor and has the above-described position control / load control functions is used, and this driver is generally a dedicated device according to the type of each servo motor. Conventionally, the control system is configured so that the control from the position control to the load control is performed by controlling the dedicated device by the overall control function of the bonding device.

[0004]

However, in the raising / lowering operation control of the bonding tool of the above-mentioned conventional bonding apparatus, contact detection during the lowering operation and control mode switching are controlled by the overall control function of the bonding apparatus. For this reason, there are problems that the signal transmission path for contact detection and control mode switching becomes complicated, the control speed decreases, high-speed operation becomes difficult, and the control program creation load of the entire apparatus increases. .

Therefore, an object of the present invention is to provide a bonding apparatus and a bonding method capable of switching control modes in bonding operation at high speed.

[0006]

A bonding apparatus according to claim 1 is a bonding apparatus for press-bonding to a surface to be bonded while applying a load to a bonding object by the bonding tool, and a motor for driving the bonding tool. , A motor control unit for controlling this motor,
With a host controller that controls the entire bonding apparatus,
The motor control unit supplies an electric power to the motor while selectively switching between a position control method and a torque control method, a storage unit that stores an operation program relating to a bonding operation and a control variable used for controlling the bonding operation. A drive unit and a subordinate control unit that controls the motor via the motor drive unit, and in the control of the motor by the subordinate control unit, the subordinate control unit controls the motor based on the operation program. The first control mode and the second control mode in which the motor is controlled based on a command from the host controller without executing the operation program are switched and controlled.

A bonding apparatus according to a second aspect is the bonding apparatus according to the first aspect, wherein the control variable stored in the storage section can be rewritten by the upper control section.

According to a third aspect of the bonding method, a motor for driving the bonding tool, a motor control section for controlling the motor, and a storage section for storing an operation program relating to the bonding operation and control variables used for controlling the bonding operation. A motor drive unit that supplies electric power to the motor while selectively switching between a position control system and a torque control system; a lower-level control unit that controls the motor via the motor drive unit; A bonding method using a bonding apparatus having an upper control unit, the step of positioning the bonding tool at a predetermined position based on a command from the upper control unit, and the upper control unit to the lower control unit. The step of outputting a command to perform the bonding operation by the And performing a bonding operation by controlling the motor based on the program, if the bonding operation is completed, and a step of outputting the operation completion signal from the slave control unit to the higher control part.

According to the present invention, the control system of the motor for driving the bonding tool is selectively switched between the position control system and the torque control system to supply electric power to the motor and the motor drive unit. Motor control section including a lower control section for controlling the motor and a higher control section for controlling the entire bonding apparatus.The lower control section controls the motor based on an operation program. By switching and controlling the first control mode for controlling the motor and the second control mode for controlling the motor based on a command from the host controller without executing the operation program, the control mode in the bonding operation is changed. Switching can be performed at high speed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. 1 is a block diagram showing a configuration of a bonding apparatus according to an embodiment of the present invention, FIG. 2 is a functional block diagram showing a function of a control system of a Z-axis motor of a bonding apparatus according to an embodiment of the present invention, FIG. FIG. 4 is a flow chart of automatic operation of the bonding apparatus of one embodiment of the present invention, FIG. 4 is an operation explanatory diagram of automatic operation of the bonding apparatus of one embodiment of the present invention, and FIG. 5 is of an embodiment of the present invention. FIG. 6 is a flow chart of the bonding operation, and FIG. 6 is an explanatory diagram of the bonding operation according to the embodiment of the present invention.

First, the structure of the bonding apparatus will be described with reference to FIG. In FIG. 1, the substrate 3 is held on the moving table 2 of the positioning unit 1. The moving table 2 is moved horizontally by an X-axis motor and a Y-axis motor (not shown). The X-axis motor and the Y-axis motor are respectively an X-axis motor driver 16 and a Y-axis motor driver 17.
The substrate 3 on the moving table 2 is horizontally moved by being controlled by the controller 18 and controlled by the X-axis motor driver 16 and the Y-axis motor driver 17, and is positioned with respect to the bonding mechanism 4 described below.

A bonding mechanism 4 is arranged above the positioning portion 1. The bonding mechanism 4 includes a tool elevating mechanism 6 fixed to a vertical fixed frame 5, and the tool elevating mechanism 6 is a Z-axis motor 6a (see FIG. 2).
Is equipped with. The Z-axis motor is a Z
By being driven by the axis motor driver 13 and controlling the Z-axis motor driver 13 by the controller 18,
The bonding tool 7 moves up and down. An encoder 12 is mounted on the bonding tool 7, and when the bonding tool 7 is moved up and down, the encoder 12 moves up and down along the linear scale 11 fixed to the fixed frame 5, whereby the height position of the bonding tool 7 can be detected. It is like this. The height position detection result is transmitted to the Z-axis motor driver 13 and the control unit 18.

A supply arm 9 of the chip supply unit 10 is arranged laterally of the positioning portion 1 so as to be movable back and forth in the horizontal direction. The supply arm 9 supplies the chip 8, which is a bonding target placed on the upper surface, to the bonding tool 7. With the supply arm 9 advanced and the chip 8 positioned below the bonding tool 7, the bonding tool 7 descends, and the bonding tool 7 adsorbs and holds the chip 8.

On the side of the positioning portion 1, a camera 14 is arranged so as to be movable back and forth in the horizontal direction. The camera 14 advances below the bonding tool 7 holding the chip 8 and images the chip 8 from below. Then, the recognition result is processed by the recognition unit 15 so that the chip 8 is identified and the position is recognized. This recognition result is the control unit 18
Be transmitted to. When the chip 8 is bonded to the upper surface of the substrate 3 which is the surface to be bonded by the bonding tool 7, the control unit 18 controls the moving table 2 via the X-axis motor driver 16 and the Y-axis motor driver 17. , The chip 8 is bonded to the correct position on the substrate 3.

In the bonding process, the controller 18 controls the operation of the tool elevating mechanism 6 via the Z-axis motor driver 13 so that the bonding tool 7 descends at a predetermined speed pattern and the chip 8 is also moved. Is pressed against the substrate 3 by applying a predetermined pressing load. The control unit 18 is connected to the operation unit 19, and the operation input from the operation unit 19 enables input of various control variables used for the above-mentioned operation control, setting change, and operation during manual operation. There is.

Next, the function of the control system of the Z-axis motor of the tool lifting mechanism 6 will be described with reference to FIG. In FIG. 2, the inside of the frame 13 shows the functions of the Z-axis motor driver 13 in a functional block diagram. The Z-axis motor driver 13 includes a lower control unit 20, a storage unit 21, and a position control unit 2.
2, the position counter 23, the speed control unit 24, the speed counter 25, and the current control unit 26.

The lower control unit 20 sends and receives four types of signals A to D, which will be described later, to and from the control unit 18 as an upper control unit for controlling the operation of the entire bonding apparatus. The storage unit 21 stores a bonding operation program 21a and a control variable 21b. The control variable 21b is data such as a target value (position command or load command) used in the control of the bonding operation, and the control unit 18 causes the storage unit 21b.
It is possible to rewrite the control variable 21b stored in the.

Signal A is a bonding operation program 21.
a, control variable 21b from control unit 18 to lower control unit 20
The signal downloaded to the storage unit 21 via the is shown. The signal B is a command signal for the control mode. The command signal causes the lower control unit 20 to perform the bonding operation and the control unit 18 controls the Z-axis motor 6 to operate.
Switching to the individual control mode for controlling the operation of a. Here, there are two types of individual control modes, a position control mode and a torque control mode, and these control modes are switched depending on the operation mode. A signal C indicates a position command signal and a load command signal transmitted from the control unit 18 in the position control mode and the torque control mode. Further, the signal D is an operation completion signal for transmitting the completion of the operation by the bonding operation program in the automatic control mode.

The function of the lower control unit 20 will be described.
The lower control unit 20 performs the following two types of control according to the control mode command (signal B) from the control unit 18. First, when the automatic control mode (first control mode) is instructed, the Z-axis motor 6a is controlled based on the bonding operation program 21a and the control variable 21b stored in the storage unit 21. In this case, the subordinate control unit 20 sends a position command (signal a) indicating a target position to the position control unit 22, a control switching command (signal b) to the current control unit 26, and a target load at the time of torque control. Is output according to the bonding operation program 21a.

When the position control mode or the torque control mode (second control mode) is instructed, the subordinate control unit 20 does not execute the bonding operation program 21a, and the position instruction and load instruction from the control unit 18 are executed. On the basis of,
The Z-axis motor 6a is controlled. When the control unit 18 commands the position control mode (signal B), the lower-order control unit 20 outputs a control switching command (signal b) to switch the control system of the current control unit 26 to the position control system, and also from the control unit 18. The position command (signal C) is relayed and the position command (signal a) is output to the position control unit 22. On the other hand, when the control unit 18 commands the torque control mode (signal B), the lower control unit 2
0 outputs the control switching command (signal b) to output the current control unit 26.
The control method is switched to the torque control method, and the load command (signal C) from the control unit 18 is relayed to output the load command (signal c) to the current control unit 26.

The position controller 22 receives a position command (signal a)
Then, based on the position signal (signal d) from the position counter 23, a speed command (signal e) indicating the target speed for reaching the target position is output to the speed control unit 24. The position signal (signal d) indicates the height position of the bonding tool 7, and is generated by the position counter 23 based on the pulse signal from the encoder 12. This position signal is also output to the lower control unit 20.

The speed controller 24, based on the speed command (signal e) and the speed signal (signal f) from the speed counter 25, a current command (signal g) indicating a target current for driving the Z-axis motor 6a. Is output to the current control unit 26.
The speed signal (signal f) indicates the ascending / descending speed of the bonding tool 7, and is generated by the speed counter 25 based on the pulse signal from the encoder 12. This speed signal is also output to the lower control unit 20.

The current controller 26 switches the control system between the position control system and the torque control system in response to the control switching command (signal b). In the case of the position control method, the speed control unit 24
The drive current i is output to the Z-axis motor 6a based on the current command (signal g) output from the Z-axis motor 6a. Then, the drive current i is output to the Z-axis motor 6a. As a result, drive power is supplied to the Z-axis motor 6a. Therefore, the current control unit 26 is a motor drive unit that supplies electric power to the Z-axis motor 6a while selectively switching between the position control system and the torque control system. That is, the subordinate control unit 20 controls the Z-axis motor 6 a via the current control unit 26.

This bonding apparatus is constructed as described above. Next, the automatic operation mode of this bonding apparatus will be described with reference to FIGS. 3 and 4.

In FIG. 3, the position control mode is first instructed by the control unit 18, and the lower control unit 20 receiving this command outputs a control switching command (signal b) to the current control unit 26 to switch to the position control system. (ST1). Next, the control unit 18 controls the position command Z0 for raising the bonding tool 7.
Is output. In response to this, the lower control unit 20 sends the position command Z
0 (signal a) is output, a current command (signal g) is output to the current control unit 26 via the position control unit 22 and the speed control unit 24, and the current control unit 26 is based on this current command (signal g). The drive current i is output to the Z-axis motor 6a to drive it.

As a result, as shown in FIG. 4 (a), the bonding tool 7 is elevated to the target position corresponding to the position command Z0 and is positioned at the predetermined position (ST2). This position command Z0 corresponds to the standby position of the bonding tool 7. Next, as shown in FIG. 4 (b), the supply arm 9 on which the chip 8 is mounted advances below the bonding tool 7 to supply the chip 8 (ST3), and the position command Z1 is output from the controller 18. Then, the bonding tool 7 descends with respect to the chip 8 to the target position corresponding to the position command Z1. This position command Z1 corresponds to the chip suction height.

As a result, the chip 8 is attracted by the bonding tool 7 (ST5). After this, FIG. 4 (c)
As shown in FIG.
Accordingly, the supply arm 9 is retracted (ST6). Although the supply arm 9 moves back and forth and the bonding tool 7 only moves up and down in this example, the bonding tool 7 may be made to perform a chip suction operation that combines vertical movement and horizontal movement. Good.

Thereafter, as shown in FIG. 4 (d), the camera 1
4 advances below the bonding tool 7, recognizes the chip 8 held by the bonding tool 7 from below, and recognizes the substrate 3 (FIG. 1) below. As a result, a relative positional error between the substrate 3 and the chip 8 is detected, and the moving table 2 is driven based on this positional error to perform an alignment operation for correcting the positional error (ST7).

Next, the control unit 18 issues an instruction for the automatic operation mode to the subordinate control unit 20 (ST8), that is, an instruction for performing a predetermined bonding operation according to the bonding operation program is output. As a result, the chip 8 is bonded to the substrate 3. Then, the operation completion signal set in the bonding operation program is the control unit 18
If it is received by ST, it is judged that the bonding operation is completed (ST9), and the position control system is restored (ST1).
0), 1 cycle of automatic operation is completed.

Next, referring to FIGS. 5 and 6, the above (ST
The bonding operation executed in the automatic control mode 8) will be described. FIG. 6 shows a temporal change in the height position of the bonding tool 7 in the bonding operation,
The relationship between the control switching command and the load command is shown. At the time of starting the bonding operation, the bonding tool 7 is at the predetermined standby position corresponding to the position command Z0 by sucking the chip 8 as shown in FIG.

When the bonding operation is started, in FIG. 5, the control method is first selected by the control switching command from the lower order control unit 20 (ST11). Next, lower control unit 2
0 outputs a position command Z2 (signal a) for lowering the bonding tool 7 to drive the Z-axis motor 6a.
The position command Z2 is stored in the storage unit 21 as a control variable 21b. Then, as shown in FIG. 6B, the bonding tool 7 descends according to the position command Z2 (S
T12). The position command Z2 corresponds to the switching height of the descending speed, and when the height corresponding to the position command Z2 is reached, the descending speed is switched to the low speed and the torque limit function is turned ON (ST13).

The torque limit function is a function of setting an upper limit value of the drive current i so that no more current is supplied to the Z-axis motor 6a, whereby the control mode changes from simple position control to torque limit. The contact position control is switched to, and an excessive load on the chip 8 when the chip 8 contacts the substrate 3 while the bonding tool 7 is descending is prevented.

After this, the position command Z from the lower control unit 20 is issued.
3 is output, and the bonding tool 7 descends at a low speed to a height where the position command Z3 is the target position. In this process, a search operation is performed (ST14). In this search operation, contact detection for detecting contact between the chip 8 and the substrate 3 is performed (ST15). That is, the speed signal (signal f) from the speed counter 25 is monitored by the lower-order control unit 20, and the time point when this speed starts to rapidly decrease is determined to be “contact”. In this contact detection, since the Z-axis position detection is performed by the Z-axis motor driver 13, the resolution is higher than that of the conventional control method, that is, the method of detecting the Z-axis position by the function of the control unit 18. It is possible to detect.

Then, as shown in FIG.
When the substrate 3 contacts the substrate 3 and the contact is detected by the lower control unit 20, the lower control unit 20 outputs a control switching command (signal b) to switch the control system of the current control unit 26 to the torque control system ( ST16). And the lower control unit 20
Outputs a load command F1 (signal c) to the current control unit 26, whereby a torque generated by the Z-axis motor 6a applies a bonding load corresponding to the load command F1 (ST17), and this state is maintained for a predetermined time. Only T1 is retained. When the time T1 has elapsed (ST18), the load command F2 is switched to the load command F2 as shown in FIG.
When a predetermined time T2 has passed (ST20), the lower control unit 20 outputs a control switching command (signal b) to apply a bonding load corresponding to the current control unit 2 (ST19).
The control method of No. 6 is returned to the position control method (ST21).

Next, a position command Z0 is output from the subordinate control unit 20, whereby the bonding tool 7 after bonding the chip 8 to the substrate 3 is changed from the state shown in FIG. (ST22). After that, it is confirmed that the Z axis has stopped (ST23), and the lower-order control unit 20 to the control unit 18
An operation completion signal is output to (ST24). This completes one cycle of the bonding operation performed in the automatic control mode according to the bonding operation program.

As described above, in this bonding method, the step of positioning the bonding tool 7 at a predetermined standby position on the basis of a command from the control unit 18 as an upper control unit, and the control unit 18 to the lower control unit 20. And a step of outputting a command to perform bonding operation to the lower controller 20 based on the bonding operation program 21a.
It includes a step of controlling the shaft motor 6a to perform a bonding operation, and a step of outputting an operation completion signal from the lower-order control unit 20 to the control unit 18 when the bonding operation is completed.

In the process in which the lower control unit 20 controls the Z-axis motor 6a based on the bonding operation program 21a to perform the bonding operation, contact detection and control method switching are performed independently of the control unit 18 in the Z-axis motor. Since this is performed by the internal function of the driver 13, the signal transmission path is simplified as compared with the conventional method in which these processes are performed by the overall control function of the control unit 18, thereby realizing high-speed operation.

In addition, since the bonding operation executed in the automatic control mode in the automatic operation can be handled as an independent operation step, it is possible to reduce the operation program creation load of the bonding apparatus (control unit 18). .

In the above embodiment, only the example of the bonding operation is shown as the operation program to be automatically executed in the automatic control mode, but other operations such as the chip suction operation and the ascending / descending operation of the bonding head 7 are involved. Similarly, the operation of can be executed in the automatic control mode.

[0040]

According to the present invention, the motor drive unit for supplying electric power to the motor while selectively switching the position control system and the torque control system for the control system of the motor for driving the bonding tool, and the motor drive unit. The motor control unit having a lower control unit for controlling the motor via the upper control unit for controlling the entire bonding apparatus. Since the first control mode for controlling the motor based on the control and the second control mode for controlling the motor based on the command from the host controller without executing the operation program are switched and controlled, the bonding operation is performed. The control mode can be switched at high speed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a bonding apparatus according to an embodiment of the present invention.

FIG. 2 is a Z of the bonding apparatus according to the embodiment of the present invention.
Functional block diagram showing the functions of the axis motor control system

FIG. 3 is a flow chart of automatic operation of the bonding apparatus according to the embodiment of the present invention.

FIG. 4 is an operation explanatory view of the automatic operation of the bonding apparatus according to the embodiment of the present invention.

FIG. 5 is a flowchart of a bonding operation according to the embodiment of the present invention.

FIG. 6 is an explanatory diagram of a bonding operation according to the embodiment of the present invention.

[Explanation of symbols]

3 substrates 4 Bonding mechanism 6 Tool lifting mechanism 6a Z-axis motor 7 Bonding tool 8 chips 13 Z-axis motor driver 18 Control unit 20 Lower controller 21 Memory 21a Bonding operation program 21b Control variable 22 Position controller 24 Speed control unit 26 Current controller

Claims (3)

[Claims] 1. A bonding apparatus for applying pressure to a surface to be bonded while applying a load to a bonding object by a bonding tool, a motor for driving the bonding tool, and a motor control section for controlling the motor.
With a host controller that controls the entire bonding apparatus,
The motor control unit supplies an electric power to the motor while selectively switching between a position control method and a torque control method, a storage unit that stores an operation program relating to a bonding operation and a control variable used for controlling the bonding operation. A drive unit and a subordinate control unit that controls the motor via the motor drive unit, and in the control of the motor by the subordinate control unit, the subordinate control unit controls the motor based on the operation program. A bonding apparatus, wherein the control mode of No. 1 and a second control mode of controlling a motor are switched and controlled based on a command from the host controller without executing an operation program. 2. The bonding apparatus according to claim 1, wherein the control variable stored in the storage unit can be rewritten by the upper control unit. 3. A motor for driving a bonding tool,
A motor control unit that controls the motor, a storage unit that stores an operation program related to the bonding operation and a control variable used to control the bonding operation, and a power supply to the motor while selectively switching the position control method and the torque control method. A bonding method using a bonding apparatus, comprising: a motor drive unit for supplying the motor; a lower control unit for controlling the motor via the motor drive unit; and an upper control unit for controlling the entire bonding apparatus. A position of the bonding tool at a predetermined position based on a command from the control unit, a step of outputting a command to perform a bonding operation from the upper control unit to the lower control unit, and the lower control unit instructing the operation program. A step of controlling the motor based on the bonding operation, If There was complete, bonding method which comprises a step of outputting an operation completion signal from the slave control unit to the higher control part.