JP2001007136A - Device and method for cleaning transfer head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate surplus flux by aligning and contacting a cleaning part to the lower surface of a transfer head and instructing a cleaning operation. SOLUTION: A cleaning part 12 is composed on a stage that is a holding surface in parallel with the lower surface of a transfer head 13, and a nonwoven cloth 18 that is a flux absorbent being larger than the transfer region of the transfer head 13 is freely removably arranged. Then, the cleaning part 12 is aligned to the lower surface of the transfer head 13, then the lower surface of the transfer head 13 is brought into contact with the nonwoven cloth 18 of a flux absorbent, and then a cleaning operation is instructed by a control device, thus surplus flux can be removed so that it is absorbed by a flux absorbent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for cleaning a transfer head used for transferring a flux in a ball mounting apparatus for mounting a solder ball or a solder bump on a wafer or a substrate.

[0002]

2. Description of the Related Art In a conventional solder ball mounting apparatus, it is known that when a flux is transferred from a transfer head to a work, the flux remains on a transfer projection of the transfer head, and the remaining flux deteriorates transfer quality. . When the transfer projection is used for the transfer head, the flux rises through the transfer projection and remains between the transfer projections.

In such a case, the solder ball mounting device is stopped, and a cloth or the like impregnated with a solvent is used.
The operation of manually wiping the transfer head has been performed. However, there is a problem that a loss occurs due to stopping the operating solder ball mounting apparatus, and the management becomes ambiguous.

[0004]

SUMMARY OF THE INVENTION The present invention provides a flux transfer head cleaning apparatus and method for removing excess flux by bringing the transfer head into contact with a cleaning section without stopping the solder ball mounting apparatus. It is an object of the present invention to solve the above problems.

[0005]

According to a first aspect of the present invention, there is provided a transfer head for supplying a flux to a large number of transfer projections formed on a lower surface to transfer a flux to a work, and a transfer head for solving the above problems. A cleaning unit in which a flux absorbing material is detachably arranged on a holding surface parallel to the lower surface,
It is an object of the present invention to provide a transfer head cleaning device, comprising: a drive unit for positioning and contacting a cleaning unit and a lower surface of a transfer head; and a control unit for instructing a cleaning operation.

According to a second aspect of the present invention, there is provided a method of transferring flux to a workpiece by supplying flux to a large number of transfer projections formed on a lower surface of a transfer head, wherein a flux absorbing material is removed from a holding surface parallel to the lower surface of the transfer head. A freely disposed cleaning unit is provided, and in accordance with a cleaning operation command from the control unit, the lower surface of the cleaning unit and the transfer head are aligned by the driving unit, and then the transfer head is brought into contact with the cleaning unit. And a method of cleaning the transfer head.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a solder ball mounting device showing one embodiment. The solder ball mounting device includes a wafer supply unit 1, a flux transfer unit 2, a ball mount unit 3, and a work driving mechanism 4. The cleaning device of the transfer head according to the present invention is provided in the flux transfer unit 2.

The wafer supply unit 1 includes a wafer cassette 5 for supply, a wafer cassette 6 for unloading, a wafer cassette 7 for defect, and a scalar robot 9 for clean room for transferring wafers. And a wafer positioning position 8 on the work drive mechanism 4.

As shown in FIG. 2, two CCD cameras 31 are arranged above the wafer positioning position 8 so as to overlap each other in the drawing (only one front camera is shown in the drawing). ), Below, an illuminator 32 facing the wafer is provided. The CCD camera 31 is movable by a motor 33 in a direction parallel to the work drive mechanism 4 (X-axis direction) above the wafer positioning position 8 on the work drive mechanism 4.

The work drive mechanism 4 includes a wafer stage 3
0 is provided, and a two-axis drive mechanism for driving the wafer stage 30 is provided, that is, an X-axis (left-right direction in FIG. 1) and a Θ-axis (rotation direction). The Θ-axis drive mechanism is a drive mechanism whose main role is positioning, while the X-axis drive mechanism has a role of moving the work and a role of positioning.

The wafer stage 30 is moved by an X-axis driving mechanism to a wafer positioning position 8 and a flux transfer position 11.
And the movement between the ball mounting positions 20 can be stopped. The wafer stage 30 is provided with two CCD cameras 23 and 23 'for observing the transfer head 13 and the mount head 25.

The flux transfer unit 2 includes a transfer head 13 and a drive mechanism thereof, a flux supply device 10, a flux transfer position 11 on a work drive mechanism 4, and a transfer head 13 provided on a moving path of the transfer head 13. And a cleaning unit 12.

The transfer head 13 of the flux supply device 10
Has a large number of transfer projections formed on the lower surface, and supplies flux to the transfer projections to transfer the flux to the work. As shown in FIG. 3, the transfer head 13 moves between the flux transfer position 11 on the flux driving device 10 and the flux transfer position 11 on the work drive mechanism 4 and the cleaning unit 12.
There is provided a two-axis drive mechanism of a shaft and a Z-axis (elevation shaft).

In the figure, reference numeral 34 denotes a Z-axis drive motor of the transfer head 13, and reference numeral 34 'denotes a Y-axis drive motor. The two-axis drive mechanism also serves as a drive unit for positioning and contacting the cleaning unit 12 and the lower surface of the transfer head 13. The Y-axis drive mechanism is also used for positioning the transfer head 13 and the work.

The flux supply device 10 is provided with a flat flux leveling section 14, and the squeegee 15 can level the flux to a constant thickness. A flux supply section 16 corresponding to the flux transfer area of the transfer head 13 is formed in the flux leveling section 14. The flux supply unit 16 can be moved up and down by a predetermined amount by a servomotor, and rises when the flux is transferred to the transfer head 13.

The cleaning device includes a cleaning unit 12
, Driving means for positioning and contact, and control means for instructing a cleaning operation. The feature of the present invention resides in the cleaning unit 12 of the transfer head 13, and the cleaning unit 12 is configured as a stage that is a holding surface parallel to the lower surface of the transfer head 13. On the upper surface of the cleaning unit 12, a non-woven fabric 18, which is a flux absorbing material and is larger than the transfer area of the transfer head 13, is removably disposed.

The nonwoven fabric 18 is removably disposed on the cleaning section 12, but may be of an automatic exchange type or a fixed type. If the roll type is used, the replacement frequency is reduced. In addition, paper may be used in place of the nonwoven fabric 18 as long as dust and dust are not generated and the flux is absorptive.

The cleaning unit 12 may be provided on the side of the moving path of the transfer head 13 so that the cleaning unit 12 can advance and retreat from the side to the moving path of the transfer head 13 during cleaning.

The cleaning device includes a cleaning unit 1
2 and the lower surface of the transfer head 13, and thereafter, a drive device for bringing the lower surface of the transfer head 13 into contact with the nonwoven fabric 18 as a flux absorbing material, and a control device (not shown) for instructing a cleaning operation. Is provided.

The driving device of the cleaning device uses a Y-axis and Z-axis driving mechanism of the transfer head 13. In the case where the cleaning unit 12 adopts a method of moving back and forth to the transfer path of the transfer head 13, a drive mechanism for moving back and forth to the transfer path is also used. Note that a rule for inputting the instruction timing of the cleaning operation to the control device may be determined in advance, or an operator may arbitrarily issue an instruction.

The cleaning unit 12 is provided near the flux transfer position 11. In the illustrated embodiment, between the flux supply device 10 and the flux transfer position 11,
It is provided on the movement path of the transfer head 13. As another embodiment, the cleaning unit 12, the flux supply device 10,
It is also possible to provide the flux transfer positions 11 in this order. Considering an operation cycle in which the cleaning operation is not performed every time, it seems that providing the cleaning unit 12 at that position is more efficient.

The ball mounting section 3 includes a mounting head 2
5 and its driving mechanism, a ball supply device 19, a ball mounting position 20 on the work driving mechanism 4, an excess ball removing device 21 disposed therebetween, a ball suction error inspection device, and a ball suction error inspection device. And a ball discharge device 24 that enters below the mount head 25 when an excess ball is detected.

The ball supply device 19 is configured as a parts feeder, and a vibrator is attached to a ball tray 27 that supplies solder balls to the mount head 25. The vibration of the vibrator causes the solder ball to jump up obliquely upward, and when viewed from above, the solder ball moves around the inside of the ball tray 27.

Above the ball tray 27, a supply port 28 for supplying solder balls from the ball stocker (not shown) into the ball tray 27 is disposed so as to be able to move forward and backward.
A sensor 29 for detecting the remaining amount of the ball in the ball tray 27 is attached to the tip of the supply port 28, and when a shortage of the remaining amount of the ball is detected, a fixed amount of the solder ball is supplied from the ball stocker. The supply port 28 has a structure in which the mount head 25 is evacuated to the outside of the ball tray 27 to avoid interference when the solder ball is attracted by the mount head 25.

The surplus ball removing device 21 is a removal nozzle for removing the surplus balls adsorbed on the mount head 25.

As shown in FIG. 4, the mount head 25 has a Y-axis reciprocating between a ball supply device 19 and a ball mounting position 20 on the work drive mechanism 4, and a Z-axis (elevation axis). A drive mechanism for the shaft is provided. In the figure, reference numeral 35 denotes a Z-axis drive motor, and reference numeral 35 'denotes a Y-axis drive motor. The Y-axis driving mechanism here is used for positioning the mount head 25 and the work together with the role of the movement of the mount head 25.

The ball suction error inspection device detects a suction error such as a missing ball or an extra ball (excess ball) and a mounting ball which is a mounting error by the four line CCD cameras 22 and 22 '.

Hereinafter, an operation procedure of the solder ball mounting apparatus according to the present embodiment will be described. First, the robot 9 supplies wafers one by one from the supply wafer cassette 5 onto the wafer stage 30 at the wafer positioning position 8. When a wafer is supplied, the wafer stage 30 starts vacuum suction through a hole on the upper surface of the wafer stage 30 through a blower motor (not shown) to hold the wafer.

The target mark or the wiring pattern of the held wafer is read by two CCD cameras 31 disposed above the wafer positioning position 8, and the position of the wafer on the wafer stage 30 is recognized and shown in the figure. Data is sent to a control device that is not running. After the wafer position recognition is completed, the wafer stage 30 is moved to the flux transfer position 1.
Sent to 1. At this time, the wafer stops at a position that takes into account the deviation of the X axis stored at the time of wafer positioning.

Next, in the flux supply device 10, the flux surface is leveled by the squeegee 15,
When the transfer head 13 comes into contact with the flux supply unit 16 and a load of a predetermined pressure or more is applied, it is determined that the supply of the flux has ended, and the lowering of the transfer head 13 is stopped.
To rise.

Thereafter, the wafer is moved to the flux transfer position 11, and the alignment marks of the transfer head 13 are recognized by the two CCD cameras 23 and 23 'provided on the wafer stage 30. The position of the wafer and the transfer head 13 are aligned with one axis (Y axis) of the transfer head 13 and two axes (X axis, Θ axis) of the wafer stage 30 by adding the position data of the previously recognized wafer to the recognition result. The alignment is performed as follows.

After the alignment, the transfer head 13 is lowered, and when the load on the Z-axis drive motor 34 of the transfer head 13 reaches a certain value, it is determined that the transfer is completed.
To rise. After ascending, the transfer head 13 returns to the flux supply device 10, and the wafer stage 30 moves to the ball mounting position 20.

The transfer head 13 is instructed to perform a cleaning operation by the control device in accordance with the set number of times, and the Y-axis drive motor 34 'is operated to move to the cleaning unit 12, and the position of the cleaning unit 12 and the transfer head 13 is changed. Perform alignment. After that, the transfer head 13 is moved down by operating the Z-axis drive motor 34 and brought into contact with the nonwoven fabric 18. At this time, the transfer head 13 is pressed against the nonwoven fabric 18 while controlling the load by the control device that controls the Z-axis drive motor 34 and the Y-axis drive motor 34 ′.
The excess flux remaining on the non-woven fabric 18 is removed by the non-woven fabric 18.

On the other hand, the mount head 25 descends from above the ball supply device 19 and stops at a specified position, and applies a suction force to the mount head 25 from a blower motor (not shown) to attract the solder balls to the lower surface of the mount head 25. Let it. When the internal pressure of the mount head 25 becomes lower than the predetermined pressure, it is determined that the suction is completed, and the mount head 25 is raised. Thereafter, the surplus balls are removed by the surplus ball removing device 21 and the apparatus moves to a ball suction error inspection device.

If there is a ball suction error, if the ball is a missing ball, it is moved to the ball supply device 19 again and the suction operation is repeated. If there is an excess ball, the ball discharge device 24 enters below the mount head 25, discharges all the suction balls into the ball discharge device 24, moves to the ball supply device 19 again, and repeats the suction operation.

If there is no abnormality, the ball is moved to the ball mounting position 20. At the ball mounting position 20, the CCD cameras 23, 2
At 3 ', the alignment mark on the lower surface of the mount head 25 is recognized, and positioning is performed in the same manner as the flux transfer position. After the positioning, the mount head 25 descends, mounts the solder balls on the wafer at the ball mounting position 20, and then moves up.

After the mounting of the solder balls is completed, the wafer stage 30 returns to the wafer positioning position 8. The CCD camera 31 previously moved to the ball mounting inspection position inspects the mounting state of the solder balls on the wafer.

At this time, the CCD camera 31 is stopped, and the movement of the wafer stage 30 causes the CCD camera 31 to move.
Scans the entire surface. As a result of the inspection, if the mount is good, the robot 9 inserts it into the unloading wafer cassette 6 if the mount is not good, and into the defective wafer cassette 7 if the mount is bad.

[0039]

The present invention provides a cleaning unit in which a transfer head for supplying a flux to a large number of transfer projections and transferring a flux to a workpiece is detachably disposed on a holding surface parallel to the lower surface of the transfer head. In addition, since the contact is performed after the alignment, the transfer head can be brought into contact with the cleaning unit and the excess flux can be removed by the flux absorbing material without stopping the solder ball mounting device. It became something.

Accordingly, since cleaning can be performed periodically, no flux remains on the transfer projections of the transfer head, and stable transfer of the flux from the transfer head to the work can be performed, and the transfer quality does not deteriorate. . Furthermore, since it is not necessary to stop the operating solder ball device and manually wipe off the excess flux remaining in the transfer head by hand, there is no loss and no problem that the management becomes ambiguous.

[Brief description of the drawings]

FIG. 1 is a plan view of a solder ball mounting device.

FIG. 2 is an explanatory view showing a CCD camera for inspection at a wafer positioning position.

FIG. 3 is a side view of a flux transfer unit.

FIG. 4 is a side view of a ball mount unit.

[Explanation of symbols]

 1. . . . . . . . 1. Wafer supply unit . . . . . . . Flux transfer unit 3. . . . . . . . Ball mount part 4. . . . . . . . Work drive mechanism 5, 6, 7. . . . 7. Wafer cassette . . . . . . . 8. Wafer positioning position . . . . . . . Robot 10. . . . . . . Flux supply device 11. . . . . . . 11. Flux transfer position . . . . . . Cleaning unit 13. . . . . . . Transfer head 14. . . . . . . Flux leveling part 15. . . . . . . Squeegee 16. . . . . . . Flux supply unit 18. . . . . . . Non-woven fabric 19. . . . . . . Ball supply device 20. . . . . . . Ball mount position 21. . . . . . . Excess ball removing device 22, 22 ', 23, 23', 31. . . CCD camera 24. . . . . . . Ball discharge device 25. . . . . . . Mount head 27. . . . . . . Ball tray 28. . . . . . . Supply port 29. . . . . . . Sensor 30. . . . . . . Wafer stage 32. . . . . . . Illuminators 33, 34, 34 ', 35, 35'. . . motor

Claims (2)

[Claims] 1. A transfer head for supplying flux to a large number of transfer projections formed on a lower surface to transfer a flux to a workpiece, and a cleaning device in which a flux absorbing material is detachably disposed on a holding surface parallel to the lower surface of the transfer head. And a drive unit for aligning and contacting the cleaning unit and the lower surface of the transfer head, and a control unit for instructing a cleaning operation. 2. A method for transferring flux to a workpiece by supplying flux to a large number of transfer projections formed on a lower surface of a transfer head, wherein a flux absorbing material is detachably disposed on a holding surface parallel to the lower surface of the transfer head. A transfer unit, wherein the lower surface of the transfer unit and the cleaning unit are aligned by the drive unit in accordance with a cleaning operation command from the control unit, and then the transfer head is brought into contact with the cleaning unit. How to clean the head.