JP3395614B2 - 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, the conductive balls stored in a container or the like are vacuum sucked and picked up by a large number of suction holes formed in the lower surface of the suction head, and the suction head is moved above the workpiece to remove these conductive balls. Since it is transferred onto the electrode of the work and a large number of conductive balls can be transferred onto the work all at once, there is an advantage that the workability is good.

By the way, as the number of conductive balls to be collectively transferred increases and the transfer tact becomes shorter, the amount of conductive balls consumed per unit time increases. On the other hand, the maximum storage amount of the ball supply unit in which the conductive balls are stored is because there is a restriction on the storage depth of the conductive balls that is appropriate for stable vacuum suction of the conductive balls by the suction head. It cannot be increased beyond the limit. For this reason, the operator has to manually replenish the ball supply portion with the conductive balls once every 15 to 30 minutes, and it has been desired to automate this work to save labor.

[0004]

Therefore, various attempts have been made to automate the ball supply work. Like parts feeders, they convey conductive balls to the ball supply unit by vibration, or supply conductive balls stored in the container to the ball supply unit by opening and closing the shutter provided in the container. For example

However, in the case of using a vibration such as a parts feeder, the conductive balls are rubbed against each other, and as a result, minute scratches are generated on the ball surface, and the scratches adversely affect the accuracy of recognition by an optical method. There was a problem that caused. Further, in the method using a shutter, a conductive ball is caught in a sliding portion of the shutter mechanism, which causes a problem in machine operation. As described above, the conventional conductive ball transfer device has a problem that it is difficult to automate the replenishment of the conductive balls without any problems in terms of quality or machine operation.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a conductive ball transfer device and a transfer method capable of automating the supply of conductive balls without any problems in quality or machine operation.

[0007]

According to a first aspect of the present invention, there is provided a conductive ball transfer device, wherein a suction head having a plurality of suction holes for sucking the conductive balls is formed on a lower surface, and the conductive balls are attached to the suction head. A ball supply unit for supplying a ball, a positioning unit for positioning the work, a vertical movement unit for vertically moving the suction head, a moving unit for moving the suction head between the ball supply unit and the positioning unit, and the ball supply. A ball replenishing means for replenishing the conductive balls to the portion, the ball replenishing means stores the conductive balls, and an elastic member that hangs down to communicate with the lower portion of the container and the tip end portion thereof opens above the ball supply portion. A tube and a tube bending means for bending the elastic tube are used.

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. In the method of transferring a conductive ball, when the conductive balls stored in the ball supply unit become less than or equal to a predetermined amount, the conductive balls stored in a container of replenishing conductive balls are The conductive ball from the opening of the elastic tube is communicated with the lower portion of the container and is guided into an elastic tube whose tip portion is open above the ball supply portion and which is bent by a tube bending means. Was controlled to replenish the ball supply portion with conductive balls.

According to the present invention, the conductive balls in the container of the replenishing conductive balls are connected to the lower portion of the container to bend the elastic tube opening to the ball supply portion to bend the elastic tube from the elastic tube to the ball tank. By controlling the outflow of the conductive balls that are replenished, quality defects such as scratches on the surface of the conductive balls and machine operation defects due to the conductive balls being caught in the sliding parts may occur. It is possible to automate the replenishment work of the conductive balls.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) FIG. 1 is a front view of a conductive ball transfer device according to Embodiment 1 of the present invention.
(A) and (b) are sectional views of a ball replenishing unit of the same conductive ball transfer device, FIGS. 3 and 4 are partial sectional views of a ball supply unit of the same conductive ball transfer device, and FIG. It is a partial front view of a positioning table of the transfer device of the conductive ball.

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. A holder 3 is provided on the positioning table 2, and the holder 3 holds the work 4. Therefore, the work 4 is positioned at a predetermined position by driving the positioning table 2.

A supply unit 6 for the conductive balls 5 is arranged at the end of the base 1 opposite to the positioning table 2. The ball supply unit 6 comprises a ball tank 7, and the conductive balls 5 are stored inside the ball tank 7. The ball replenishing unit 8 for the conductive balls 5 is provided diagonally above the ball supplying unit 6.
Is provided.

The ball replenishing unit 8 will be described below with reference to FIGS. 2 (a) and 2 (b). As shown in FIGS. 2A and 2B, the ball replenishing unit 8 has a container 9 for storing the electrically conductive balls 5 for replenishment, an elastic tube 10 communicating with the lower portion of the container 9, and the elastic tube 10. Is composed of a cylinder 11 as a tube bending means for bending the elastic tube 10 by vertically moving the tip end of the cylinder 11. The container 9 has a lid 9a and has a funnel-shaped lower portion. Container 9
An elastic tube 10 made of a highly flexible material such as urethane rubber or silicon rubber is connected to the lower end of the. The elastic tube 10 hangs down from the lower end of the container 9, bends, and the tip is located above the ball tank 7. The tip portion is a cylinder 11 via a tube holder 12.
It is held by a rod 11a of which the cross section of the tip is an opening 10a.

As shown in FIG. 2A, when the rod 11a of the cylinder 11 is retracted, the elastic tube 10 is bent and the opening 10a is in a position facing upward from the horizontal posture. The conductive balls 5 in the tube 10 are stationary and do not flow out from the opening 10a. On the other hand, as shown in FIG.
When the rod 11a of No. 1 protrudes, the opening 10a tilts downward from the horizontal posture, and the conductive balls 5 stored in the container 9 flow out from the opening 10a through the elastic tube 10 and enter the ball tank 7. To fall.

Further, by changing the lower limit position of the rod 11a of the cylinder 11 to change the bending state of the elastic tube 10 and adjusting the inclination of the opening 10a, the outflow amount of the conductive balls 5 can be changed. . That is, the outflow of the conductive balls 5 from the elastic tube 10 can be controlled by changing the bending state by changing the vertical movement of the cylinder 11 and the stroke amount thereof. Opening 1
The angle required for the conductive balls 5 to flow out from 0a, and the amount of outflow for each angle are determined from the relationship between the material and the tube diameter of the elastic tube 10, the ball diameter of the conductive balls 5, and the like. Obtained by trial.

The following effects can be obtained by using the above-mentioned mechanism as a means for replenishing the conductive balls 5. First, when the conductive balls 5 are transferred from the replenishing container 9 to the ball tank 7, the conductive balls 5 are not subjected to an excessive external force or mechanical vibration. Therefore, the conductive balls 5 are not deformed and the surface is not scratched,
No quality problems occur. Further, since it is not necessary to open and close the supply path by a mechanical mechanism such as a shutter, troubles such as the conductive ball 5 being caught in the sliding portion do not occur, and the opening 11a is simply moved up and down by the cylinder 11. The supply of the conductive balls 5 can be controlled by a simple mechanism.

Next, the suction head 31 for transferring the conductive balls 5 will be described with reference to FIGS. 1 and 3. Figure 1
Reference numeral 20 denotes a moving unit that moves the suction head 31 between the ball supply unit 6 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. As shown in FIG. 3, in parallel with the suction head 31,
The sensor 32 is provided downward. Sensor 32
Is a conductive ball in the ball tank 7 when the suction head 31 is located on the ball tank 7 and light is emitted downward at the timing when the lower surface of the suction head 31 is at a predetermined height and the reflected light is received. It is detected whether or not the level of the upper surface of 5 is within a predetermined range H suitable for vacuum-sucking the conductive balls 5 shown in FIG.

The block 30 is vertically movably mounted on a vertical guide rail (not shown) provided on the front surface of the bracket 24. A nut 28 is integrally provided on the block 30, and a vertical feed screw 26 is screwed onto the nut 28. Therefore, when the Z-axis motor 27 is driven in the normal direction and the feed screw 26 is rotated in the normal direction, the suction head 31 is rotated.
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 29 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. When the X-axis motor 23 rotates in the forward and reverse directions, the feed screw 22 rotates in the forward and reverse directions, and the suction head 31 held by the bracket 24 moves to the positioning table 2.
And the ball supply unit 6 are horizontally moved. Therefore, the X-axis motor 23 and the feed screw 22 are moving means for moving the suction head 31 horizontally.

In FIG. 1, the control unit 33 receives the level detection result of the conductive balls 5 from the sensor 32, and receives the result from the cylinder 1
1 and the up-and-down operation of the transfer device 1, and the operation of the entire transfer device such as the X-axis motor 23 and the Y-axis motor 27.

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 6. Therefore, the Z-axis motor 2
7 is driven to lower the suction head 31, and the lower surface of the suction head 31 is slightly submerged in the layer of the conductive balls 5 as shown in FIG. By vacuum suction from the suction holes 31a in this state, the conductive balls 5 are vacuum suctioned to the suction holes 31a.

The suction head 31 picking up the conductive balls 5 by vacuum suction moves up from the ball supply section 6,
Then, it moves horizontally above the positioning table 2. Next, the suction head 31 descends onto the work 4 held by the holder 3, and by releasing the vacuum suction, the conductive ball 5 is transferred onto the electrode 4a as shown in FIG. The transfer of the ball 5 is completed.

In the process of continuing this transfer operation continuously, the conductive balls 5 in the ball tank 7 are consumed, and the level of the upper surface of the conductive balls 5 gradually decreases. When this level becomes close to the predetermined level set as the ball replenishment level, the ball replenishment unit 8 causes the ball tank 7
Conductive balls are provided therein. The control of the ball supply operation at this time can be performed by the two methods described below.

The first method is based on the upper surface level of the conductive balls 5 in the ball tank 7. When the suction head 31 is located above the ball tank 7 and the lower surface of the suction head 31 is at a predetermined height, the sensor 32 causes the ball tank 7 to move.
The level of the conductive balls 5 inside is detected. If this level is below a predetermined level, the rod 11a of the cylinder 11 of the ball replenishing section 8 is lowered to cause the conductive balls 5 to flow out from the opening 10a of the elastic tube 10 and be replenished in the ball tank 7. When the outflow of the conductive balls 5 continues for a predetermined time, the required amount of the conductive balls 5 is replenished in the ball tank 7.

Another replenishment method is to calculate and store the number of continuous transferable times from the data of the number of conductive balls 5 that are collectively transferred and the total number of conductive balls 5 that can be stored in the ball tank 7. In this method, the actual number of times of transfer is counted when the transfer device is in operation, and when the count is close to the number of times transfer is possible, an instruction to execute replenishment is given.

(Second Embodiment) FIGS. 6 and 7 are sectional views of a ball replenishing portion of a conductive ball transfer device according to a second embodiment of the present invention. As shown in FIG. 6, the ball replenishing unit 8 ′ has a container 12 for storing the electrically conductive balls 5 for replenishment, an elastic tube 13 communicating with a lower portion of the container 12, and a tip portion of the elastic tube 13 which moves up and down. And a tube bending means for bending the middle portion of the elastic tube 13. The ball replenishing section 8 ′ is arranged diagonally above the ball replenishing section 6 like the ball replenishing section 8 in the first embodiment.

In FIG. 6, the tip of the elastic tube 13 is fixed to the holder 14. The holder 14 is connected to the rod 15a of the cylinder 15. A shaft 16 is mounted on the holder 14 so as to be slidable in the left-right direction. A cap 16 is provided on the right end of the shaft 16.
a is provided, and the cap 16a is an elastic tube 1
It is in the same plane as 3. A roller 18 is mounted on the left end of the shaft 16, and a compression spring 17 is mounted between the mounting portion of the roller 18 and the side surface of the holder 14. The compression spring 17 constantly urges the roller 18 to the left, and presses the roller 18 against the cam 19 having a sloped cam surface arranged on the left side.

As the rod 15a of the cylinder 15 projects, the holder 14 rises as shown in FIG. As a result, the lower end of the elastic tube 13 is lifted, and the roller 18 rolls on the cam surface of the cam 19, so that the shaft 16 slides to the right, and the side surface of the elastic tube 13 is moved by the cap 16a at the tip. Press to bend. That is, the holder 14 and the cylinder 1
5, the shaft 16, the roller 18, and the cam 19 are tube bending means for bending the elastic tube 13.

In the state shown in FIG. 6, the conductive balls 5 in the container 12 pass through the elastic tube 13 and flow out from the opening 13a at the tip, fall into the ball tank 7, and the conductive balls 5 are replenished. To be done. Further, by driving the cylinder 15 to bend the elastic tube 13, the conductive balls 5 frictionally contact each other in the elastic tube 13 and the inner wall surface of the elastic tube 13 as shown in FIG. By the action such as the above, it stops and the outflow of the conductive balls 5 into the ball tank 7 is interrupted.

Further, by adjusting the protruding stroke of the cylinder 15, the bending degree of the elastic tube 13 is changed, and the outflow amount of the conductive ball 5 from the opening 13a can be changed. That is, as in the first embodiment,
It is possible to control the outflow of the conductive balls 5 from the elastic tube 13 by changing the bending state of the elastic tube 13 by changing the vertical movement of the cylinder 15 and the stroke amount thereof.

[0031]

According to the present invention, the elastic tube which communicates with the lower portion of the container for storing the conductive balls for replenishment and opens above the ball supply section is bent to replenish from the elastic tube to the ball tank. Since the outflow of the conductive balls is controlled, it is possible to automate the supply operation of the conductive balls with a simple mechanism. In addition, since the external force is not applied to the conductive ball unlike the conventional method of controlling the outflow of the ball with a shutter or the method of conveying the ball by vibrating the ball like a parts feeder, the surface of the conductive ball is not affected. It does not cause quality problems such as scratches on the machine, and machine operation problems due to the conductive balls biting into the sliding parts of the mechanism.

[Brief description of drawings]

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

FIG. 2A is a sectional view of a ball replenishing portion of the conductive ball transfer device according to the first embodiment of the present invention. FIG. 2B is a ball replenishment of the conductive ball transfer device according to the first embodiment of the present invention. Sectional view

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

FIG. 5 is a partial front view of a positioning table of the conductive ball transfer device according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view of a ball replenishing portion of the conductive ball transfer device according to the second embodiment of the present invention.

FIG. 7 is a sectional view of a ball replenishing portion of the conductive ball transfer device according to the second embodiment of the present invention.

[Explanation of symbols]

1 base 2 Positioning table 4 work 5 conductive balls 6 ball supply section 7-ball tank 8, 8'ball supply section 9, 12 containers 10, 13 elastic tube 11, 15 cylinders 23 X-axis motor 27 Z-axis motor 31 Suction head 31a adsorption hole 32 sensors 33 Control unit

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-8-115917 (JP, A) JP-A-8-236916 (JP, A) JP-A-7-291226 (JP, A) JP-A-9- 306919 (JP, A) JP 60-24268 (JP, A) Actual development 61-202397 (JP, U) Actual development 60-19354 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/60 B23F 21/00 B23K 3/06 H05K 3/34 H01L 23/12 B23P 19/00 B65G 47/19 B65D 90/56

Claims (2)

(57) [Claims] 1. A suction head having a plurality of suction holes formed on its lower surface for sucking conductive balls, a ball supply unit for supplying the conductive balls to the suction head, a positioning unit for positioning a work, and the suction unit. The ball replenishing means includes a vertically moving means for moving the head up and down, a moving means for moving the suction head between a ball supply portion and a positioning portion, and a ball replenishing means for replenishing conductive balls to the ball supply portion. A container for storing the conductive balls; an elastic tube which is connected to the lower part of the container and hangs down; and a tip portion of which is open above the ball supply portion; and a tube bending means for bending the elastic tube. Transfer device for conductive balls. 2. A conductive ball transfer method for transferring a conductive ball of a ball supply section onto a work by a suction head having a plurality of suction holes for sucking conductive balls formed on a lower surface thereof. When the amount of conductive balls stored in the supply unit becomes less than a predetermined amount, the conductive balls stored in the container of replenishing conductive balls are communicated with the lower portion of the container and the leading end portion is hung down. By guiding the elastic tube into an elastic tube opening above the ball supply section and bending the elastic tube by a tube bending means, the outflow of the conductive balls from the opening section of the elastic tube is controlled to conduct the electric current to the ball supply section. A method for transferring conductive balls, which comprises replenishing conductive balls.