JP2001012914A - Method and apparatus for positioning and ball mount inspection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the uselessness of providing optical units individually by an arrangement wherein an optical system recognizing means moves relatively to a work stage to pick up the image of a work and performs both positioning of the work and ball mount inspection after mounting. SOLUTION: A wafer is provided on a wafer stage 30 at a wafer positioning position 8 and positioning data is obtained from the attitude of the wafer where the image of an alignment mark on the surface of the wafer is picked up by means of CCD cameras 23, 23'. Subsequently, the wafer stage 30 moves to a flux transfer position 11 and stops thereat, the CCD cameras 23, 23' pick up the image of a transfer head and then the transfer head is aligned with the wafer while taking account of wafer position data. The wafer stage 30 moves to a mount position 20 after transfer and the CCD cameras 23, 23' position the mount head before solder balls are mounted on the wafer. Subsequently, the wafer stage 30 returns back to the wafer positioning position 8 and the CCD cameras 23, 23' inspect the mounting state of the solder balls on the wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an apparatus and method for positioning a work and inspecting a ball mount after the work is used in a ball mount apparatus for mounting a solder ball or a solder bump on a wafer or a substrate. It is.

[0002]

2. Description of the Related Art Conventionally, there has been known an apparatus using an optical device for positioning a work in a solder ball mounting apparatus. There is also known an apparatus that performs a ball mount inspection by an optical device after mounting. However, in each case, the optical devices are provided separately, which is wasteful.

[0003]

SUMMARY OF THE INVENTION The present invention eliminates the waste of separately providing an optical device for positioning a work and an optical device for inspecting a ball mount after mounting, and uses the same optical system recognition means to position the work. And an apparatus and a method for performing ball mounting inspection after mounting.

[0004]

According to a first aspect of the present invention, there is provided a work stage for holding a work;
An optical system recognizing unit that performs both positioning and ball mounting inspection after mounting by imaging a work on a work stage, and a driving unit that relatively moves the optical system recognizing unit and the work stage. And a ball mount inspection device.

According to a second aspect of the present invention, the optical system recognizing means and the work stage holding the work are relatively moved by the driving means, the work of the work stage is imaged by the optical system recognizing means, and positioning before mounting and after mounting are performed. And a ball mounting inspection method using the same optical system recognizing means.

[0006]

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 apparatus according to the present invention. The solder ball mounting device includes: a wafer supply unit 1;
It comprises a flux transfer section 2, a ball mount section 3, and a work drive mechanism 4. The work positioning and ball mount inspection apparatus according to the present invention comprises a work drive mechanism 4.
Exists.

In this embodiment, the work is a wafer 18, and an alignment mark 17 used for positioning is provided on the surface of the wafer 18 as shown in FIG.
The solder balls are provided at four positions inside the vicinity of the outline of No. 8 where the solder balls are not mounted.

The wafer supply unit 1 includes a wafer cassette 5 for supply, a wafer cassette 6 for unloading, a wafer cassette 7 for defective wafers, and a scalar robot 9 for a clean room for transferring wafers 18. And the wafer positioning position 8 on the work drive mechanism 4.

A feature of the present invention resides in a wafer positioning position 8 of the work drive mechanism 4. A line CCD camera 31 is disposed above the wafer positioning position 8 as shown in FIG. The CCD camera 31 is an optical system recognizing means for recognizing the alignment mark 17 for work positioning on the work stage and performing a ball mount inspection after mounting.

Two CCD cameras 31 are arranged so as to overlap each other in FIG. 2 (only one in front is shown in the drawing), and the two CCD cameras 31 cover the entire width of the wafer 18. can do. CCD camera 31
An illuminator 32 facing the wafer 18 is below the CCD.
It is provided so as to be movable integrally with the camera 31.

The CCD camera 31 is movable above the wafer positioning position 8 on the work drive mechanism 4 in a direction parallel to the work drive mechanism 4 (X-axis direction) by a motor 33 serving as a drive source of the X-axis drive mechanism. It has been.

The work drive mechanism 4 is provided with a wafer stage 30 which is a work stage for holding the work. The work stage has an X-axis (left-right direction in FIG. 1) and a Θ-axis (rotation direction) for driving the wafer stage 30. A two-axis drive mechanism is provided. 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.

That is, an X-axis driving mechanism for the CCD camera 31, an X-axis driving mechanism for the wafer stage 30, and a Θ-axis driving mechanism are provided as driving means for relatively moving the CCD camera 31 and the wafer stage 30 as a work stage. Have been.

The movement of the wafer stage 30 between the wafer positioning position 8, the flux transfer position 11, and the ball mount position 20 can be stopped by the X-axis drive mechanism. The transfer head 1 is mounted on the wafer stage 30.
3 and 2 CCDs for observing the mount head 25
Cameras 23 and 23 'are provided.

The flux transfer section 2 includes a transfer head 13 and a drive mechanism thereof, a flux supply device 10, and a flux transfer position 11 on a work drive mechanism 4. A part 12 is provided.

Transfer head 13 of flux supply device 10
As shown in FIG. 3, the flux supply device 10
There is provided a two-axis drive mechanism of a Y-axis and a Z-axis (elevation axis) which reciprocate between the flux transfer position 11 on the work drive mechanism 4 and the flux transfer position 11. 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 Y-axis driving mechanism here is used for positioning the transfer head 13 and the work together with the role of the transfer head 13 to move.

The flux supply device 10 is provided with a flat flux leveling portion, 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.

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 arranged so as to be able to advance and retreat.
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 supply port 28 is retracted outside the ball tray 27 in order to avoid interference with the mount head 25 at the time of solder ball suction.

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

As shown in FIG. 4, the mount head 25 has a Y-axis reciprocating between the ball supply device 19 and a ball mount 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 remaining ball as a mounting error by using 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 wafers 18 are supplied one by one from the supply wafer cassette 5 by the robot 9 onto the wafer stage 30 at the wafer positioning position 8. When the wafer 18 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).
Hold.

When the wafer 18 is supplied to the wafer stage 30, the two CCD cameras 31 arranged above the wafer positioning position 8 move the alignment marks 17 formed on the surface of the wafer 18 shown in FIG. Stopped at a position where imaging can be performed. The CCD camera 31 recognizes the attitude of the wafer 18 on the wafer stage 30 based on the alignment mark 17 and uses it as positioning data. The positioning data is sent to a control device (not shown). When the position recognition of the wafer 18 is completed, the wafer stage 30 moves to the flux transfer position 11. 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. Taking into account the position data of the previously recognized wafer 18 to this recognition result, the wafer 18 is moved by one axis (Y axis) of the transfer head 13 and two axes (X axis, Θ axis) of the wafer stage 30.
And the transfer head 13 are aligned.

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.

On the other hand, the mount head 25 descends from above the ball supply device 19 and stops at a designated position, and is supplied with a suction force from a blower motor (not shown) to attract the solder balls to the lower surface of the mount head 25. 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 is lowered to mount the solder balls on the wafer 18 at the ball mounting position 20,
Then rise.

After the mounting of the solder balls is completed, the wafer stage 30 returns to the wafer positioning position 8. When the wafer stage 30 returns to the wafer positioning position 8, the CCD camera 31 has previously moved to the ball mount inspection position and stopped. The ball mount inspection position may be the same as the position where the alignment mark 17 on the wafer 18 can be imaged. The CCD camera 31 inspects the mounting state of the solder balls on the wafer.

A work drive mechanism 4 is provided below the CCD camera 31.
When the wafer stage 30 moves, the entire surface of the wafer 18 on the wafer stage is scanned by the CCD camera 31 and the image of the wafer 18 is continuously captured.
Determine if the ball mount is defective.

As a result of the inspection, if the ball mount on the wafer 18 is good, the robot 9 inserts the wafer 18 into the unloading wafer cassette 6 if the ball mount is bad, and into the defective wafer cassette 7 if the ball mount is bad.

[0035]

According to the present invention, there is provided a work stage for holding a work, an optical system recognizing means for taking an image of the work on the work stage and performing both positioning and ball mounting inspection after mounting, an optical system recognizing means and a work stage. And a drive means for relatively moving the optical disk, thereby eliminating the need for separately providing an optical device for positioning the workpiece and an optical device for inspecting the ball mount after mounting.

[Brief description of the drawings]

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

FIG. 2 is an explanatory view showing an apparatus for positioning and ball mounting inspection.

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

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

FIG. 5 is an explanatory view showing an alignment mark of a wafer.

[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 15. . . . . . . Squeegee 16. . . . . . . Flux supply unit 17. . . . . . . Alignment mark 18. . . . . . . Wafer 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

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference)

Claims (2)

[Claims] 1. A work stage for holding a work, an optical system recognizing means for imaging the work on the work stage to perform both positioning and ball mounting inspection after mounting, and moving the optical system recognizing means and the work stage relative to each other. A device for positioning a work and inspecting a ball mount, comprising a driving means. 2. The optical system recognizing means and the work stage holding the work are relatively moved by the driving means, the work of the work stage is imaged by the optical system recognizing means, and positioning before mounting and ball mounting inspection after mounting are performed. And performing ball mounting inspection using the same optical system recognition means.