JP3376879B2 - 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, when a plurality of conductive balls are vacuum-sucked in one suction hole and a large number of conductive balls are continuously attached to the lower surface of the suction head, or when the conductive balls are attached to a position other than the suction hole. The suction head may rise as it is. In the method using the suction head as described above, a pickup error in which extra conductive balls adhere to the lower surface of the suction head is apt to occur, and the conductive balls may not be properly transferred one by one onto the electrodes of the work. There was a problem.

In view of this, the present invention removes the conductive balls that are excessively attached to the lower surface of the suction head due to a pickup error, and can transfer the conductive balls onto the electrodes of the workpiece correctly. And to provide a transfer method.

[0007]

According to a first aspect of the present invention, there is provided a conductive ball transfer device having a suction head having a plurality of suction holes for sucking the conductive balls formed on a lower surface thereof, and a ball supplying the conductive balls. A supply part, a positioning part for positioning a work, a vertical movement means for vertically moving the suction head, a moving means for horizontally moving the suction head, and a conductive ball excessively attached to the lower surface of the suction head. A brush for removing only the conductive balls other than the conductive balls that are properly attracted to the suction holes of the suction head by slidingly contacting the conductive balls on the lower surface of the suction head to the removal section. Are arranged in the X and Y directions.

According to a second aspect of the present invention, there is provided a conductive ball transfer method in which conductive balls in a ball supply portion are transferred to a work by a suction head having a plurality of suction holes for sucking the conductive balls formed on a lower surface thereof. A method for transferring a conductive ball, wherein the suction head having a conductive ball attracted to the lower surface selectively brushes off only the conductive ball other than the conductive ball that is correctly attracted to the suction hole of the suction head. Are located at a predetermined interval with respect to the removing portions arranged in the X direction and the Y direction, and the suction head is opposed to the brush while the brush is in sliding contact with the conductive balls on the lower surface of the suction head. By moving horizontally in the X direction and the Y direction, the conductive balls excessively attached to the lower surface of the suction head are removed.

According to the present invention having the above-described structure, the suction head having the conductive balls vacuum-sucked on its lower surface is a brush for selectively removing only the conductive balls adhered to positions other than the suction holes of the suction head in the X direction. And the removal part disposed in the Y direction, and the suction head is horizontally moved in the X direction and the Y direction relative to the brush to bring the brush into sliding contact with the conductive ball. Besides, it is possible to remove the conductive balls that are excessively attached.

[0010]

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, and FIG. 2A is a partial sectional view of a conductive ball removal portion of the conductive ball transfer device. 5B is a partial plan view of a conductive ball removing portion of the same conductive ball transfer device, and FIGS. 3 and 4 are partial cross-sectional views of a ball supply portion of the same conductive ball transfer device.
6A and 6B are partial cross-sectional views of a conductive ball removing portion of the same conductive ball transfer device, and FIG. 6 is a partial front view of a positioning table of the same 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.

A supply unit 10 for the conductive balls 7 is arranged on the base 1 at the end opposite to the positioning table 2. The ball supply unit 10 includes a ball tank 11, and a plurality of layers of mesh plates 12 are horizontally spread inside the ball tank 11. The mesh plate 12 is provided with an innumerable number of openings whose size does not allow the conductive balls 7 to pass through. The conductive balls 7 are stored on the uppermost mesh plate 12. A nozzle 14 is arranged at the bottom of the ball tank 11, and the nozzle 14 is connected to a gas supply source (not shown). By supplying the gas to the nozzle 14, the gas blown upward from the nozzle 14 passes through the openings of the mesh plate 12 and is blown into the layer of the conductive balls 7 to fluidize 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 in the X direction (horizontal direction in FIG. 1), which moves the Y table 30 between the ball supply unit 10 and the positioning table 2. The Y table 30 includes a Y-axis motor 32,
The suction head 31 held on the Y table 30 is horizontally moved in the Y direction (the vertical direction of the drawing in FIG. 1).

A plurality of suction holes 3 are formed on the lower surface of the suction head 31.
1a is provided. The Y table 30 is the bracket 2
4 is mounted on a vertical guide rail 25 provided on the front surface of the unit 4 so as to be vertically movable. The Y table 30 has a nut 2
8 is integrally provided, and a vertical feed screw 26 is screwed into the nut 28. Therefore, the Z-axis motor 27
When the feed screw 26 rotates in the normal and reverse directions and rotates in the normal and reverse directions, 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 onto the horizontal feed screw 22.
Reference numeral 21 is a holding table for the feed screw 22. Therefore, when the X-axis motor 23 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. Therefore, the moving means 20 in the X direction and the Y table 30 are moving means for moving the suction head 31 in the horizontal direction.

In FIG. 1, a ball supply unit 1 on a base 1
A removing portion 40 for the conductive balls 7 is arranged on the side of 0. The removing unit 40 removes the conductive balls 7 excessively attached to the lower surface of the suction head 31. As shown in FIGS. 1 and 2, a ball receiver 45 is placed on the box 41, and a base portion 42 is fixed in the ball receiver 45. A plate 43 is mounted on the base 42. As shown in FIG. 2B, the plate 43 has a brush row 44X and a brush row 44Y in the X and Y directions.
Are arranged in an inverted L shape.

These brush row 44X and brush row 4
The 4Y brush 44 slidably contacts the conductive balls 7 attached to the lower surface of the suction head 31 to remove the excessively attached conductive balls 7. By appropriately setting the strength of these brushes 44 (determined by the rigidity, length, number of individual bristles constituting the brushes, etc.), the suction head 31 is brought into contact with the brushes 44 while slidingly contacting the conductive balls 7. Is horizontally moved in the X direction and the Y direction by a distance corresponding to the width and depth length of the lower surface of the suction head 31 with respect to the removal portion 40, the conductive material correctly vacuum-sucked in the suction hole 31a of the suction head 31. The elastic balls 7 do not exert a force that causes them to fall from the attracted state, and the conductive balls 7 that have adhered to other than the attracting holes 31a have a force sufficient to cause them to fall from an unstable attached state. Can be exerted. Therefore, the suction holes 31a
Besides, the conductive balls 7 that are excessively attached can be selectively blown off.

In this embodiment, one brush row 44X in the X direction and one brush row 44Y in the Y direction are provided, but a plurality of brush rows 44X and 44Y may be provided. In this case, the brush row 44
As the number of rows of X and 44Y increases, the suction head 31
Since it is sufficient that the distance for horizontally moving the removing unit 40 with respect to the removing unit 40 is short, the time required for the removing operation can be shortened.

This conductive ball transfer device has the above-mentioned structure, and its operation will be described below. First, in FIG. 1, the X-axis motor 23 is driven to move the suction head 31 above the ball supply unit 10. Then, the Z-axis motor 27 is driven to lower the suction head 31, and the lower surface of the suction head 31 is slightly sunk into the layer of the conductive balls 7 as shown in FIG. At this time, the nozzle 14 of the ball tank 11
More gas is blown upward (see arrow a), and the conductive balls 7 are fluidized by the flow of this gas. Therefore, the conductive ball 7 is blown up, hits the lower surface of the suction head 31 and is vacuum-sucked in the suction hole 31a.

At this time, as shown in FIG. 4, the suction head 31 may ascend while the extra conductive balls 7 are attached to positions other than the suction holes 31a on the lower surface of the suction head 31. Although FIG. 4 shows an example in which one extra conductive ball 7 is attached, in addition to this example, in the case where a plurality of conductive balls 7 are attached in series, the extra conductive balls 7 are attached.
There are various modes of attachment.

Conductive balls 7 attached in such an extra manner
Are removed by the removing unit 40. First, the suction head 31 that has suctioned the conductive balls 7 is moved to above the removing unit 40, and then the suction head 31 is lowered with respect to the plate 43. If the tip of the brush 44 and the lower surface of the suction head 31 have a predetermined positional relationship, that is, if the brush 44 descends to a height position where it slides on the conductive ball 7 on the lower surface of the suction head 31, The suction head 31 is horizontally moved relative to the plate 43 in the X and Y directions by a predetermined distance (see arrow c). This allows
The brush 44 is in sliding contact with the conductive ball 7 on the lower surface of the suction head 31, but the brush 44 is in a suction state with respect to the conductive ball 7 that has been properly suctioned in the suction hole 31a as shown in FIG. 5A. Since it does not exert a force sufficient to drop the conductive ball 7 from the
Remains adsorbed in the adsorption holes 31a even after the brush 44 is in sliding contact.

On the other hand, since the conductive balls 7 attached to the portions other than the suction holes 31a are in an unstable attached state, they are easily attracted by sliding the brush 44 as shown in FIG. 5 (b). The state of being attached to the lower surface of the head 31 (see FIG.
The conductive balls 7 shown by the broken line in (b) fall off (see arrow d) and fall into the ball receiver 45 to be collected.

In addition, the conductive balls 7 that are excessively attached are
The conductive balls 7 that have been properly vacuum-sucked are arranged in series in the sliding contact direction of the brush, and the conductive balls 7 that have excessively adhered are placed behind the conductive balls 7 that have been correctly vacuum-sucked in the suction holes 31a. If the brush 44 is in a so-called blind spot position (see the hatched conductive balls 7 shown in FIG. 5A), the brush 44 is removed from the conductive balls 7 that are excessively attached. It is hard to work.
Even in such a case, by moving the suction head 31 relative to the plate 43 in the X and Y directions, the brush rows 44X and 44Y can be moved with respect to all the conductive balls 7.
The brush 44 of any one of the above parts is brought into sliding contact with each other, and no blind spot occurs in the action of the brush 44.

As described above, the suction heads 31 that have picked up the conductive balls 7 by vacuum suction one by one in all the suction holes 31a are lifted from the removing section 40, and then horizontally moved above the positioning table 2. Next, the suction head 31 descends onto the work 6 held by the holder 5, and
As shown in (4), the vacuum suction is released, the conductive balls 7 are transferred onto the electrodes 6a, and thereafter, the conductive balls 7 are raised to complete the transfer of the conductive balls 7.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the conductive ball removing portion 40 is fixed, and the suction head 3 is attached to the removing portion 40.
1, the removal unit 40 is movable, and the suction head 3 is stationary on the ball supply unit 10.
It is also possible to move the removing portion 40 with respect to 1 to remove the excessively attached conductive balls 7.

[0026]

As described above, according to the present invention, the brush for sucking the conductive balls of the ball supply portion selectively blows off only the conductive balls attached to positions other than the suction holes of the suction head in the X direction. Since the horizontal movement is performed in the X direction and the Y direction relative to the removing portions arranged in the Y and Y directions, it is possible to remove the conductive balls extraly attached to the portions other than the suction holes quickly and reliably. Therefore, the conductive balls can be surely transferred one by one onto the electrodes of the work.

[Brief description of drawings]

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

2A is a partial cross-sectional view of a conductive ball removing portion of a conductive ball transfer device according to an embodiment of the present invention. FIG. 2B is a conductive ball transfer according to an embodiment of the present invention. Partial plan view of conductive ball removal section of device

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. 4 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. 5A is a partial cross-sectional view of a conductive ball removing portion of a conductive ball transfer device according to an embodiment of the present invention. FIG. 5B is a conductive ball transfer according to an embodiment of the present invention. Partial cross-sectional view of the removed portion of the conductive ball of the device

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]

1 base 2 Positioning table 6 work 7 conductive balls 10-ball feeder 11 ball tank 23 X-axis motor 27 Z-axis motor 31 Suction head 31a adsorption hole 32 Y-axis motor 40 Remover 44 brushes 44X, 44Y brush row

Claims (2)

(57) [Claims] 1. A suction head having a plurality of suction holes for sucking conductive balls formed on a lower surface thereof, a ball supply unit for supplying the conductive balls, and a positioning unit for positioning a work.
An up-and-down moving unit for moving the suction head up and down, a moving unit for horizontally moving the suction head, and a removing unit for removing the conductive balls excessively attached to the lower surface of the suction head are provided in the removing unit. Brushes are provided in the X direction and the Y direction for sliding off the conductive balls on the lower surface of the suction head and selectively brushing off only the conductive balls other than the conductive balls that have been correctly sucked in the suction holes of the suction head. A transfer device for conductive balls, characterized in that 2. A conductive ball transfer method for transferring a conductive ball of a ball supply unit onto a work by means of a suction head having a plurality of suction holes for sucking conductive balls formed on a lower surface thereof. A brush provided in the X direction and the Y direction for selectively removing only the conductive balls other than the conductive balls that have been correctly sucked in the suction holes of the suction head from the suction head that has attracted the conductive balls. And a horizontal movement of the suction head relative to the brush in the X and Y directions while keeping the brush in sliding contact with the conductive balls on the lower surface of the suction head. The method for transferring conductive balls is characterized in that the conductive balls excessively attached to the lower surface of the suction head are removed.