JP2002134888A - Mounting device for conductive balls - Google Patents

Abstract

(57) [Problem] To provide a conductive ball mounting device capable of preventing damage such as deformation and surface damage of the conductive ball. SOLUTION: In a conductive ball mounting apparatus for vacuum-holding and holding a conductive ball in an aligned state, which is accommodated in a concave portion 15a provided in an aligning portion 15 by a mounting head and mounted on a work, a concave portion on the aligning portion 15 is provided. In the ball aligning operation of accommodating and aligning the conductive balls in the ball 15a and in the ball sucking operation of sucking the conductive balls from the aligning unit 15 by the mounting head, a component (the aligning unit 15) that constitutes a range that comes into contact with the conductive balls. , Ball movement restricting member 1
9, the suction tool of the mounting head) is made of a resin material softer than the solder which is the material of the conductive balls. As a result, it is possible to prevent the conductive balls from being deformed or damaged such as surface scratches.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive ball mounting apparatus for mounting conductive balls supplied in an aligned state on a work.

[0002]

2. Description of the Related Art As a method of forming a metal bump on an electrode of a substrate or an electronic component, there is known a method of mounting a conductive ball such as a solder ball (hereinafter simply abbreviated as "ball") on an electrode and performing solder bonding. Have been. For mounting a ball, a method of vacuum-sucking the ball with a mounting head is widely used. In this method, a ball is suctioned into a large number of suction holes provided in a suction tool of a mounting head, the mounting head is moved, and the vacuum suction is released to mount the ball at a predetermined position.

[0003] As a method of adsorbing a ball to a suction tool, instead of a method of lowering a mounting head to a ball tank storing a large number of balls and directly sucking and holding the ball on the lower surface of the suction tool, a method of preliminarily mounting the mounting head is described. A method has been adopted in which conductive balls are arranged on an alignment member having a concave portion formed at a position corresponding to the arrangement of the suction holes.
According to this method, there is an advantage that the ball can be quickly and correctly held in each suction hole of the suction tool at the time of ball pickup.

[0004]

In the supply of the ball, a ball alignment operation is performed in which the ball flows on the upper surface of the alignment portion and is accommodated in the concave portion. In this ball aligning operation, the ball moves on the aligning portion, or the ball movement restricts the ball so that the ball does not flow at an excessive moving speed, and further applies vibration to the aligning portion. For example, the movement of the ball into the recess is promoted. For this reason, deformation and fine surface flaws of the ball occur during the aligning operation and the subsequent suction operation by the mounting head, which causes a problem in the subsequent ball mounting process and bump forming process.

Accordingly, an object of the present invention is to provide a conductive ball mounting apparatus capable of preventing damage such as deformation and surface damage of the conductive ball.

[0006]

According to a first aspect of the present invention, there is provided a conductive ball mounting apparatus for mounting a conductive ball on a workpiece by holding the conductive ball by vacuum suction by a mounting head and mounting the conductive ball on a work. A mounting head having a plurality of suction holes formed therein, an alignment portion provided with a plurality of concave portions on the upper surface capable of accommodating one conductive ball in the same arrangement as the suction holes, and a conductive ball provided on the alignment portion. Ball supplying means for supplying conductive balls in the concave portion on the aligning portion and aligning the conductive balls in the concave portion, and in the ball sucking operation for sucking the conductive balls from the aligning portion by the mounting head. At least, the material of the alignment portion among the components constituting the range that makes contact with the conductive ball is made of a resin material that is softer than the material of the conductive ball.

According to a second aspect of the present invention, there is provided a conductive ball mounting apparatus according to the first aspect.
The material of the suction tool in which the suction holes of the mounting head are formed is made of the resin material.

According to a third aspect of the present invention, there is provided the conductive ball mounting apparatus according to the first aspect.
A ball movement restricting member for restricting the flow of the conductive ball on the alignment portion is provided, and a material of the ball movement restricting member in a range in contact with the conductive ball is made of the resin material.

According to the present invention having the above structure, in the ball aligning operation for accommodating the conductive ball in the concave portion on the aligning portion and the ball sucking operation for sucking the conductive ball from the aligning portion by the mounting head, By making the material of the constituent part constituting the contact area a resin softer than the conductive ball, it is possible to prevent the conductive ball from being deformed or damaged such as a surface scratch.

[0010]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a perspective view of a conductive ball mounting apparatus according to one embodiment of the present invention, FIG. 2 is a perspective view of a ball alignment apparatus of the conductive ball mounting apparatus according to one embodiment of the present invention, and FIG. FIG. 4 is a structural diagram of an alignment jig of a conductive ball mounting device according to an embodiment of the present invention. FIG. 4 is a block diagram showing a configuration of a control system of the conductive ball mounting device of one embodiment of the present invention. FIG. 6 is a process explanatory view of a ball aligning operation of the conductive ball mounting device according to one embodiment of the present invention, and FIG. 6 is a diagram illustrating ball circulation in an alignment jig of the conductive ball mounting device of one embodiment of the present invention. FIG.

First, the structure of the conductive ball mounting device will be described with reference to FIG. In FIG. 1, a positioning unit 2 is provided on a base 1, and a substrate 3 as a work is mounted on the positioning unit 2. A ball aligning device 4 that supplies conductive balls (hereinafter, abbreviated as “balls”) in an aligned state is provided beside the positioning section 2. The ball alignment device 4 is configured by arranging an alignment jig 5 via a support table 7 on a base portion 6 supported by a tilt mechanism 9 so as to be tiltable with respect to a horizontal plane. A moving mechanism 8 for a ball movement restricting member, which will be described later, is provided on the base 6.

A ball mounting section 10 is disposed above the positioning section 2 and the ball aligning device 4. The ball mounting unit 10 is configured by combining a moving table 11 and a moving mechanism 12 and mounting a mounting head 13 on the moving mechanism 12. The moving table 11 moves the moving mechanism 12 in the X direction, and the moving mechanism 12 moves the mounting head 13 in three directions of YZθ. As a result, the mounting head 13 becomes XYZθ
In four directions. Mounting head 13
The balls arranged on the alignment jig 5 of the ball aligning device 4 are suction-held by a large number of suction holes provided on the lower surface, and are mounted on the substrate 3 on the positioning unit 2. The material of the suction tool provided with the suction holes is made of a resin material softer than the solder which is the material of the balls 14.

Next, the ball aligning device 4 will be described with reference to FIGS. In FIG. 2, the base portion 6 is rotated by a predetermined angle around a rotation axis 9a by a tilting mechanism 9, whereby the base portion 6 tilts in both directions with respect to a horizontal plane. A support 7 is provided on the upper surface of the base 6.
The support jig 5 has an alignment jig 5 mounted thereon. A vibrator (not shown) is provided inside the support table 7, and the vibration is applied to the alignment jig 5 by driving the vibrator.

At both ends of the upper surface of the base portion 6, guide rails 16 are arranged in parallel in the X direction. Have been. The upper part of the post 17 is connected by a connecting member 18, and the connecting member 1
8 is provided with a ball movement restricting member 19. The ball movement restricting member 19 reciprocates in the X direction integrally with the connecting member 18 along the upper surface of the alignment jig 5 by driving the moving mechanism 8, and restricts the movement of the ball 14 on the alignment portion 15. I do. As a material in a range where the ball movement restricting member 19 comes into contact with the ball 14, a resin material softer than solder which is a material of the ball 14 is used. The moving mechanism 8 includes a nut 20 a and a nut 20 fixed to one of the posts 17.
The feed screw 20 is screwed into a, and a motor 21 for driving the feed screw 20 to rotate.

A light projecting section 22a and a light receiving section 22b constituting a ball detection sensor are attached to the left and right posts 17, respectively. The light emitted from the light projecting section 22a is received by the light receiving section 22b, The presence or absence of the ball on the optical axis of the irradiation light can be detected. Light emitting unit 22
a, the mounting height position of the light receiving portion 22b to the post 17 can be finely adjusted, and an appropriate height position is set according to the detection target.

Next, the structure of the alignment jig 5 will be described with reference to FIG. FIG. 3A shows a plane of the alignment jig 5, and FIGS. 3B and 3C show cross sections BB and C, respectively.
C is shown. As shown in FIGS. 3A and 3B, the alignment jig 5 is a substantially plate-shaped member provided with a combing portion 5a on four circumferences, and a concave portion 15a capable of accommodating only one ball 14 is provided at the center in the center. A large number of alignment portions 15 are formed in a predetermined lattice-like arrangement. The arrangement of the recesses 15a matches the arrangement of the suction holes formed on the lower surface of the mounting head 13. Here, the material of the alignment portion 15 is made of a resin material softer than the solder, which is the material of the balls 14, similarly to the suction tool of the mounting head 13.

A through hole 15b having a diameter smaller than the diameter of the ball 14 is provided on the bottom surface of the concave portion 15a, as shown in FIG.
The suction space 5 provided on the lower surface of the alignment jig 5 as shown in FIG.
By suctioning the inside of the vacuum chamber f under vacuum, vacuum suction is performed through the through hole 15b communicating with the suction space 5f. Thereby, the recess 15
The ball 14 in a is held by the vacuum suction force. The suction space 5f is connected to a suction source 24 via a valve 23, and by operating the valve 23, control of suction and release of suction can be performed.

As shown in FIGS. 3 (b) and 3 (c), the shape of the alignment portion 15 is set such that the upper surface is higher than the surroundings by a height h, and the X direction (the tilt direction of the alignment jig 5). Is formed by a slope 5c connecting the bottom surface and the upper surface of the alignment portion with a slope.
In addition, the Y direction orthogonal to the X direction is bent downward at right angles from the upper surface of the alignment section 15 by a stepped portion 15c.
It is in a form separated from the bottom surface of the alignment jig 5. A storage portion 5b for storing the ball 14 is provided between the slope portion 5c and the combing portion 5a, and a groove portion 5d for allowing the movement of the ball 14 in the X direction is provided between the step portion 15c and the combing portion 5a. It has become. 4 inside the alignment jig 5
A guide member 5e is provided at the corner, and the alignment jig 5
The circulation of the ball 14 in the inside can be performed better.

Next, the configuration of the control system will be described with reference to FIG. In FIG. 4, the ball detection sensor 22 is connected to the determination unit 25, and the determination unit 25 absorbs extra balls 14 on the alignment unit 15 and suction by the mounting head 13 based on a detection signal from the ball detection sensor 22. It is determined whether there is any suction leak ball remaining in the concave portion 15a without being sucked in the operation. The determination result is sent to the control unit 27.

The control unit 27 includes the ball movement restricting member 1.
9, a tilting mechanism 9 for tilting the alignment jig 5, a vibrator 26 for applying vibration to the alignment jig 5,
The driving of the mounting head moving mechanism 29 for moving the mounting head 13 is controlled. Further, the control unit 27 controls the operation of the ball alignment jig suction valve 23 and the mounting head suction valve 28 for performing suction by the mounting head 13.

Next, a ball alignment operation by the ball alignment device 4 will be described with reference to FIG. First, FIG.
Is a state before the start of ball alignment, and a predetermined amount of the ball 14 is supplied to the storage part 5b on one side of the alignment jig 5. In this state, the ball movement restricting member 19 is
5 at a predetermined standby position. The ball alignment operation is started from this state, and the alignment jig 5 is tilted in the ball movement direction, that is, in the direction opposite to the storage portion 5b in which the balls 14 are stored, as shown in FIG. At the same time, the vacuum suction in the suction space 5f is started. As a result, the vacuum suction from the recess 15a through the through hole 15b and the movement of the ball 14 into the recess 15a can be performed by suction.

Next, the motor 21 is driven to move the ball movement restricting member 19 at a predetermined speed along the upper surface of the inclined alignment portion 15 to supply the ball 14 to the alignment portion 15. As a result, the ball 14 in the storage part 5b is
As shown in (c), the ball is gradually moved in the inclined direction on the alignment portion 15 while being dammed by the ball movement restricting member 19 (ball moving step). Therefore, ball movement restricting member 1
Reference numeral 9 denotes a ball supply unit that moves the ball 14 on the inclined alignment unit 15 and supplies the ball 14 to the alignment unit 15.
As the ball supply unit, a configuration other than the above, for example, a configuration in which a ball storage container having an opening on the lower surface is moved along the upper surface of the alignment unit 15 may be used.

In the course of this movement, the balls 14 are held one by one in the recesses 15a (ball alignment step). At this time, the vibrator 26 is driven and the alignment jig 5
Is given vibration. Thereby, the movement of the ball 14 into the concave portion 15a is promoted. Also, the ball movement restricting member 19 blocks the ball 14 flowing along the inclined alignment portion 15 so that the ball 14
The ball 14 is held in all the recesses 15a only by inclining the alignment jig 5 once because the probability of holding the ball 14 is increased. In this ball moving step, the balls 14 overflowing from the alignment section 15 drop from the step sections 15c provided at both ends parallel to the inclination direction of the alignment section 15 into the groove section 5d, and move to the storage section 5b on the opposite side. Moving.

After that, the ball movement restricting member 19 is
5 moves to the other end and reaches the slope 5c, so that the dammed ball 14 flows downward along the slope 5c as shown in FIG. It is accommodated in the part 5b. As a result, one stroke of the ball movement restricting member 19 is completed, and the balls 14 are accommodated in the concave portions 15a of the aligning portion 15 in an aligned state.

Thereafter, as shown in FIG. 5 (e), the aligning jig 5 is returned to the horizontal position, and the ball movement restricting member 19 is moved in the direction of arrow a on the aligning portion 15, so that the aligning portion 15 is moved. An extra ball 14 existing on the upper portion is removed (a ball removing step). The lower end of the ball movement restricting member 19 does not contact the ball 14 held in the concave portion 15a, but moves on the alignment portion 15 at a height at which it contacts the ball 14 existing on the alignment portion 15. Therefore, the balls 14 remaining on the alignment portion 15 without being accommodated in the concave portion 15 a are removed from the alignment portion 15 by the ball movement restricting member 19. In the ball removing step, the ball movement restricting member 19 is made of a resin material softer than the solder of the material of the ball 14, so that the ball 14 is not scratched or deformed by the contact with the ball movement restricting member 19.

In this embodiment, the extra balls 14 on the alignment section 15 are removed by using the ball movement restricting member 19, but the extra balls 14 are stored by utilizing the inclination of the alignment jig 5. A method of dropping to the part 5b may be used. In this case, the ball alignment step and the ball removal step are performed simultaneously.

Thereafter, an extra ball inspection by the ball detection sensor 22 is performed, and if it is confirmed that there is no extra ball, a ball suction operation by the mounting head 13 is performed. When all the balls 14 arranged in the alignment unit 15 are normally suction-held by the mounting head 13 by the suction leakage ball inspection by the ball detection sensor 22, the mounting head 13 moves onto the positioning unit 2 and holds it. The ball 14 is mounted on the substrate 3.

Next, the circulation operation of the balls 14 in the alignment jig 5 will be described with reference to FIG. As described above, in the ball alignment operation, the ball 14 in the ball storage 5b is moved to the upper surface of the alignment unit 15 via the inclined surface 5c by inclining the alignment jig 5 with respect to the horizontal plane (inclination step). Then, the balls 14 are moved in the inclined direction while being dammed by the ball movement restricting member 19 (ball moving step).

In this ball moving step, the aligning section 1
The ball 14 overflowing from the upper surface of the ball 5 is dropped into the groove 5d from the step portion 15c at both ends (ends parallel to the inclined direction) of the alignment portion 15 (ball drop step). Then, the dropped ball 14 is moved by inclination in the groove 5d and guided to the ball storage 5b in the inclined direction (see arrow c) (ball return step). The groove 5d functions as a ball guide that guides the movement of the ball 14.

The ball 14 that has fallen from the groove 5d to the storage portion 5b is guided toward the center of the storage portion 5b ahead of the other balls 14 by guide members 5e provided at the four corners (see arrow d). It flows to the center of the part 5b. The ball 14 located at the center of the storage portion 5b has a higher probability of being held in the recess 15a than the balls 14 located on both sides of the storage portion 5b. When the alignment jig 5 is tilted in the opposite direction to perform the next ball alignment operation, the ball 14 moves from the ball storage portion 5b to the alignment portion 15 via the slope portion 5c (see arrow e). 14 is newly supplied onto the alignment section 15 (ball supply step).

That is, in the ball aligning operation, the respective steps of the tilting step, the ball moving step, the ball dropping step, the ball returning step, and the ball supplying step are repeatedly performed, and the ball 14 is held in the concave portion 15a in the aligning jig 5. It is configured to circulate between a position where the probability of occurrence is low and a position where the probability is high. By performing such ball circulation, the balls 14 are housed in the recesses 15 a at a predetermined probability in the circulation process, are aligned, and are taken out by the mounting head 13.

Therefore, a situation in which the specific ball 14 stays in the alignment jig 5 for a long time without being taken out by the mounting head 13 does not occur, and the surface of the ball 14 is deteriorated due to scratches caused by friction. Ball 14
This does not produce a defective ball whose damage caused by biting of excessively advanced. Further, in the ball circulation operation, since there is no operation for forcibly passing the ball 14 through the narrow gap, the degree of deformation and damage of the ball 14 is small.

Further, a recess 15a for accommodating the ball 14
Component parts such as an alignment unit 15 provided with a ball, a ball movement restricting member 19 that moves on the alignment unit 15 by contacting the balls 14, and a suction tool on the lower surface of the mounting head 13 that suctions and holds the aligned balls 14. By using a resin material that is softer than the material of the ball 14 in a range in contact with the ball 14, deformation of the ball 14 and generation of surface scratches can be prevented. As a result, the generation of the deteriorated ball having the deformation and the surface flaw is reduced, and the trouble in the subsequent process is reduced.

When selecting a resin material that is softer than the material of the ball 14, if the material to be selected is a material of such a type that an elastic coefficient which is an index indicating the degree of deformation with respect to an external force is given as a characteristic value. This elastic modulus can be used as a selection criterion. That is, a material having an elastic coefficient smaller than that of the solder may be selected.

[0035]

According to the present invention, a conductive ball is brought into contact with a conductive ball in a ball aligning operation of accommodating a conductive ball in a recess on an aligning portion and a ball sucking operation of sucking the conductive ball from the aligning portion by a mounting head. Since the material of the constituent parts constituting the range to be formed is made of a resin material softer than the conductive balls, it is possible to prevent the conductive balls from being damaged or damaged such as surface scratches.

[Brief description of the drawings]

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

FIG. 2 is a perspective view of a ball alignment device of the conductive ball mounting device according to one embodiment of the present invention.

FIG. 3 is a structural view of an alignment jig of the conductive ball mounting apparatus according to one embodiment of the present invention;

FIG. 4 is a block diagram showing a configuration of a control system of the conductive ball mounting apparatus according to one embodiment of the present invention;

FIG. 5 is a process explanatory view of a ball aligning operation of the conductive ball mounting apparatus according to one embodiment of the present invention;

FIG. 6 is an explanatory diagram of ball circulation in an alignment jig of the conductive ball mounting apparatus according to one embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 3 substrate 4 ball alignment device 5 alignment jig 5b storage unit 5c slope 5d groove 8 moving mechanism 9 tilting mechanism 13 mounting head 14 ball 15 alignment unit 15a recess 19 ball movement restricting member

Claims (3)

[Claims] 1. A conductive ball mounting apparatus for mounting a conductive ball on a workpiece while holding the conductive ball by vacuum suction by a mounting head, the mounting head having a plurality of suction holes formed on a lower surface, and one mounting head formed on an upper surface. An alignment unit having a plurality of recesses capable of accommodating the conductive balls in the same arrangement as the suction holes, and ball supply means for supplying the conductive balls on the alignment unit;
In the ball aligning operation for accommodating and aligning the conductive balls in the recesses on the aligning portion and the ball sucking operation for sucking the conductive balls from the aligning portion by the mounting head, the component forming a range that comes into contact with the conductive balls. The conductive ball mounting apparatus, wherein at least the material of the alignment portion is made of a resin material softer than the material of the conductive ball. 2. The conductive ball mounting apparatus according to claim 1, wherein a material of a suction tool in which the suction holes of the mounting head are formed is made of the resin material. 3. A ball movement restricting member for restricting a flow of the conductive ball on the alignment portion, wherein a material of the ball movement restricting member in a range in contact with the conductive ball is made of the resin material. The conductive ball mounting device according to claim 1, wherein: