JP3376875B2 - Apparatus and method for transferring conductive balls - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive ball transfer device and method for transferring conductive balls onto a work.

[0002]

2. Description of the Related Art Flip chips and BGA (Ball G)
A method using conductive balls such as solder balls is known as a method of manufacturing an electronic component with bumps such as a grid array. Further, as a method of transferring the conductive balls to a work such as a chip or a substrate, a method using a suction head has been implemented.

In this method, conductive balls stored in a container or the like are vacuum sucked and picked up by a large number of suction holes formed on the lower surface of the suction head, and the suction head is moved above the work to conduct these conductive balls. Since the conductive balls are transferred onto the electrodes of the work and a large number of conductive balls can be transferred onto the work all at once, there is an advantage that workability is good.

[0004]

However, in the method of transferring the conductive balls to the work by using the suction head, a pickup error as described below tends to occur when the conductive balls are vacuum-sucked. . That is, when the conductive balls are vacuum-sucked by the suction head, the suction head is lowered into the supply portion of the conductive balls accumulated by stacking a large number of conductive balls. However, one conductive ball is not always vacuum-adsorbed. For example, it takes time for the conductive balls to be vacuum-sucked in the suction holes, and the suction head may rise without vacuum-sucking the conductive balls depending on the suction holes. On the contrary, a plurality of conductive balls may be vacuum-sucked in one suction hole, and a large number of conductive balls may be continuously attached to the lower surface of the suction head. In the method using the suction head as described above, pick-up mistakes are likely to occur, and the conductive balls are not formed on the electrode of the work piece.
There was a problem that they were not transferred correctly one by one.

Therefore, the present invention provides a conductive ball transfer device and transfer method capable of eliminating a conductive ball pickup error and reliably transferring the conductive ball onto an electrode of a workpiece. With the goal.

[0006]

According to a first aspect of the present invention, there is provided a conductive ball transfer device for supplying a conductive ball, and a suction head having a plurality of suction holes for vacuum-sucking the conductive ball formed on its lower surface. A ball supply unit, a horizontal plate provided on the ball supply unit, an aligning unit for further aligning the conductive balls on the horizontal plate, a vibrating unit for vibrating the plate, and a suction head for moving up and down. And a vertical movement means for moving the same.

According to a second aspect of the present invention, there is provided a method of transferring conductive balls, wherein the conductive balls are further aligned by a aligning means on a horizontal plate provided in the ball supply section, and one conductive ball is provided on each lower surface. A suction head having a plurality of suction holes for sucking the conductive balls is located above the plate, and the conductive balls aligned on the plate are vacuum-sucked by the suction head while vibrating the plate by vibrating means. And a step of lowering the suction head with respect to the work, releasing vacuum suction, and raising the suction head to transfer the conductive balls onto the electrodes of the work.

The conductive ball transfer method according to claim 3 is the conductive ball transfer method according to claim 2,
In the step of vacuum-sucking the conductive balls, the suction head is positioned with a predetermined distance from the conductive balls.

A method of transferring conductive balls according to a fourth aspect is the method of transferring conductive balls according to the second aspect,
In the step of vacuum-sucking the conductive balls, the lower surface of the suction head is brought into contact with the conductive balls.

According to the present invention having the above-mentioned structure, the conductive balls are attached to the suction head while the conductive balls are further aligned on the horizontal plate provided in the ball supply section and the plate is vibrated by the vibrating means. By vacuum-sucking, the conductive balls can be correctly sucked into each suction hole one by one, and it is possible to prevent extra conductive balls from adhering to the suction tool.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a conductive ball transfer device according to an embodiment of the present invention, FIG. 2, FIG. 3, and FIG.
(A), (b), FIG. 5 is a partial cross-sectional view of a ball supply portion of the conductive ball transfer device, and FIG. 6 is a partial front view of a positioning table of the conductive ball transfer device.

First, the overall structure of the conductive ball transfer device will be described with reference to FIG. In FIG. 1, a positioning table 2 is provided on a base 1. The positioning table 2 is composed of a Y table 3 and an X table 4.
A holder 5 is provided on the X table 4, and the holder 5 holds the work 6. Therefore, the work 6 is positioned at a predetermined position by driving the positioning table 2.

On the side of the positioning table 2 on the base 1, a supply unit 10 for the conductive balls 7 is arranged.
The ball supply unit 10 includes a ball case 11 and a vertically movable plate 13. The ball case 11 is supported by the base 12. The plate 13 is a horizontally-arranged rectangular flat plate, and is provided with an edge portion 14 on the periphery. The height of the edge portion 14 is somewhat lower than the diameter of the conductive balls 7, so that the conductive balls 7 can be accommodated on the plate 13 in a more aligned state. A plurality of vibrators 16, which are vibrating means, are mounted on the lower surface of the plate 13. By driving the vibrator 16, the plate 13 vibrates, and the conductive balls 7 housed on the plate 13 vibrate vertically or horizontally.

A support member 15 is attached to the plate 13, and the support member 15 is connected to a rod 17 of a cylinder 18 installed in the base 12. Plate 13
Is fitted into the opening 11a of the ball case 11,
The plate 18 moves up and down along the inner side wall of the base 12 by the rod 18 of the cylinder 18 projecting and retracting. When the plate 13 is lowered to the bottom surface of the ball case 11 with the conductive balls 7 stored in the ball case 11,
The conductive balls 7 in the ball case 11 roll and diffuse on the plate 13.

As shown in FIG. 1, a squeegee 19 is arranged at a raised position of the plate 13 and the conductive balls 7 are provided.
The squeegee 19 horizontally moves on the plate 13 on which the conductive balls 7 having a predetermined height or more are scraped into the ball case 11, and the conductive balls 7 are further aligned on the plate 13. It is stored in. That is, the plate 13 and the squeegee 19 serve as alignment means for aligning the conductive balls 7.

Next, the suction head 31 for transferring the conductive balls 1 will be described. Reference numeral 20 shown in FIG. 1 is a moving means for moving the suction head 31 between the ball supply unit 10 and the positioning table 2. The suction head 31 is held by the block 30, and a plurality of suction holes 31 a are provided on the lower surface of the suction head 31. The block 30 is a vertical guide rail 2 provided on the front surface of the bracket 24.
It is attached to 5 so that it can move up and down. In block 30,
A nut 28 is integrally provided, and a vertical feed screw 26 is screwed into the nut 28. Therefore, when the Z-axis motor 27 is driven forward and backward and the feed screw 26 rotates forward and backward, the suction head 31 is guided by the guide rail 25 and moves up and down. Therefore, the Z-axis motor 27 and the feed screw 26 are vertical moving means for moving the suction head 31 up and down.

A nut (not shown) provided on the back surface of the bracket 24 is screwed into the horizontal feed screw 22.
Reference numeral 21 is a holding table for the feed screw 22. Therefore, when the X-axis motor 33 rotates forward and backward, the feed screw 22 rotates forward and backward, and the suction head 31 held by the bracket 24 horizontally moves between the positioning table 2 and the ball supply unit 10.

This conductive ball transfer device has the above-mentioned structure, and its operation will be described with reference to the drawings.
First, in FIG. 1, the X-axis motor 23 is driven to move the suction head 31 above the ball supply unit 10. Further, in parallel with the movement of the suction head 31, the ball supply unit 10 performs an alignment operation of the conductive balls 7 described below.

As shown in FIG. 2, the rod 17 of the cylinder 18 is retracted and the plate 13 is lowered to a level near the bottom surface of the ball case 11. Then, the conductive balls 7 stored in the ball case 11 roll and spread on the plate 13 due to the difference in height (see arrow a). Next, after the rod 17 of the cylinder 18 is projected to raise the plate 13, the squeegee 19 is horizontally moved as shown in FIG. 3 (see arrow b), and the conductive ball 7 on the plate 13 is placed in the ball case 11. Scrape off (see arrow c).
As a result, the conductive balls 7 are further aligned on the plate 13.

Next, in FIG. 1, the Z-axis motor 27 is driven to lower the suction head 31 toward the plate 13. Then, the suction head 31 is positioned on the conductive balls 7 arranged on the plate 13 to vacuum-suck the conductive balls 7 in the suction holes 31a. At this time, the relative positions of the suction head 31 and the conductive balls 7 are held. Depending on the relationship, the two methods described below are used.

First, as shown in FIG. 4A, the first method is to keep the conductive balls 7 in a state where a predetermined small space S is maintained between the lower surface of the suction head 31 and the conductive balls 7. Are vacuum-adsorbed. In this state, when vacuum suction is performed from the suction holes 31 a and the vibrator 16 is driven, the conductive balls 7 are generated by the vibration transmitted through the plate 13.
Repeats small movements vertically or horizontally.

The conductive balls 7 moved within the range of the vacuum suction force of the suction holes 31a are attracted by the suction holes 3a.
It is sucked up to the inside of 1a, and finally adheres to the inner wall surface of the suction hole 31a to be completely vacuum-sucked. At this time, since the conductive balls 7 are aligned in a single layer on the plate 13, two or more conductive balls 7 are provided in the same suction hole 31a.
Of the conductive balls 7 (denoted by a small arrow in FIG. 4 (a)), which are near the suction holes 31a and have the strongest suction force, are vacuum sucked in the suction holes 31a. To be done. Therefore, the plurality of conductive balls 7 will not be attracted and attached to one suction hole 31a.

Next, as the second method, as shown in FIG. 4 (b), the conductive ball 7 is vacuum-sucked in a state where the lower surface of the suction head 31 is lightly pressed against and brought into contact with the conductive ball 7. Is. When vacuum suction is performed from the suction holes 31a and the vibrator 16 is driven in this state, the conductive balls located immediately below the tapered portion of the suction holes 31a (see FIG. 4B).
(Denoted by a small arrow) does not abut on the lower surface of the suction head 31, so that it can move freely in the upward direction, and is immediately captured by the suction force of the suction hole 31a and vacuum-sucked.

Further, the suction hole 31a on the lower surface of the suction head 31
Vibration is transmitted to the conductive balls 7 located in the other parts than the plate 13 and the lower surface of the suction head 31, and as a result, the conductive balls 7 slightly move horizontally due to the vibration, and a certain time elapses. After that, these conductive balls 7 also come to be located immediately below the suction holes 31a which have not yet vacuum-sucked the conductive balls 7, and then the suction holes 31a.
It is vacuum-adsorbed by a. And finally all the suction holes 3
The conductive balls 7 are vacuum-adsorbed one by one on 1a.

As described above, the suction heads 31 that correctly pick up the conductive balls 7 one by one in all the suction holes 31a by vacuum suction move up from the plate 13 as shown in FIG. Move horizontally upwards. Next, the suction head 31 descends on the work 6 held by the holder 5, releases the vacuum suction to transfer the conductive balls 7 on the electrodes 6a, and then ascends as shown in FIG. Transfer of 7 is completed.

[0026]

According to the present invention, in a state where conductive balls are further aligned on a horizontal plate provided in the ball supply section, a vacuum is applied to the suction head while applying vibration to the plate by vibrating means. Since it is designed to be absorbed,
The conductive balls are quickly and correctly vacuum-sucked one by one in each suction hole, and it is possible to prevent the conductive balls from adhering excessively and transfer the conductive balls one by one onto the work electrode. it can.

[Brief description of drawings]

FIG. 1 is a front view of a conductive ball transfer device according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a ball supply unit of a conductive ball transfer device according to an embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of a ball supply unit of a conductive ball transfer device according to an embodiment of the present invention.

FIG. 4A is a partial cross-sectional view of a ball supply portion of the conductive ball transfer device according to the embodiment of the present invention. FIG. 4B is a ball of the conductive ball transfer device according to the embodiment of the present invention. Partial sectional view of the supply section

FIG. 5 is a partial cross-sectional view of a ball supply unit of the conductive ball transfer device according to the embodiment of the present invention.

FIG. 6 is a partial front view of a positioning table of the conductive ball transfer device according to the embodiment of the present invention.

[Explanation of symbols]

2 Positioning table 6 work 7 conductive balls 10 Supply Department 11 ball cases 13 plates 16 oscillators 18 cylinders 19 squeegee 20 means of transportation 23 X-axis motor 27 Z-axis motor 31 Suction head 31a adsorption hole

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21/60 B23P 21/00 305 B25J 15/06

Claims (4)

(57) [Claims] 1. A suction head having a plurality of suction holes for vacuum-sucking conductive balls formed on a lower surface thereof, a ball supply section for supplying the conductive balls, and a horizontal plate provided on the ball supply section. A conductive ball comprising: an aligning means for further aligning the conductive balls on the horizontal plate; a vibrating means for vibrating the plate; and a vertical moving means for vertically moving the suction head. Transfer device. 2. A step of further aligning the conductive balls by an aligning means on a horizontal plate provided in the ball supply part, and a plurality of suction holes for respectively attracting one conductive ball on the lower surface. A step of positioning the suction head above the plate, a step of vacuum-sucking the conductive balls aligned on the plate by the suction head while vibrating the plate by vibrating means, and the suction head with respect to the work. And a step of transferring the conductive balls onto the electrodes of the work by lowering the vacuum suction and lifting the vacuum suction, to transfer the conductive balls. 3. The transfer of the conductive ball according to claim 2, wherein in the step of vacuum-sucking the conductive ball, the suction head is positioned with a predetermined distance from the conductive ball. How to put. 4. The method of transferring a conductive ball according to claim 2, wherein in the step of vacuum-sucking the conductive ball, the lower surface of the suction head is brought into contact with the conductive ball.