Semiconductor device manufacturing: process – Making device or circuit responsive to nonelectrical signal
Reexamination Certificate
2000-02-23
2001-07-03
Bowers, Charles (Department: 2823)
Semiconductor device manufacturing: process
Making device or circuit responsive to nonelectrical signal
C438S022000, C438S025000, C438S055000, C257S678000, C257S738000
Reexamination Certificate
active
06255132
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of lining up or positioning micro-balls on a jig, the micro-balls to be formed into bumps disposed on a work for a substrate, chip, or so forth, in a micro-ball mounting apparatus of a semiconductor device manufacturing system, and particularly, to a method of lining up micro-balls on an arraying jig by feeding the micro-balls into array holes on the arraying jig having a plurality of the array holes.
2. Description of the Related Art There has already been disclosed in Japanese Patent Laid-Open No. H7-153765, and Japanese Patent Laid-Open No. H7-153766 a micro-ball mounting apparatus for mounting micro-balls on a work for a substrate, chip, or so forth, wherein an adsorption jig in a sheet-like shape is provided with a plurality of adsorption holes disposed so as to correspond to positions of electrode pads formed on a work, and a group of micro-balls in number corresponding to at least one feed thereof for the work are caused to be adsorbed to the respective adsorption holes, so that the micro-balls adsorbed to the adsorption jig are bonded to the electrode pads on the work.
As shown in
FIG. 14
, an adsorption unit of this type is provided with an adsorption head
1
which can be moved up and down by a hoisting and lowering mechanism (not shown), and the adsorption head
1
has an adsorption jig
2
in a plate-like shape, provided with a plurality of adsorption holes
2
a
for vacuum-adsorbing micro-balls which are fluidized and floated.
Further, as shown in
FIG. 15
, when sucking operation is performed by use of a suction unit (not shown) with the adsorption head
1
already lowered by the hoisting and lowering mechanism, and brought in close proximity to the micro-balls B contained in a stock dish
3
made of metal, installed in the lower part of the adsorption unit, the micro-balls B are vacuum-adsorbed to the adsorption holes
2
a
of the adsorption jig
2
.
With the adsorption unit of this type, the adsorption holes
2
a
formed in the adsorption jig
2
have a very small diameter, and consequently, air has little fluidity away from the adsorption holes
2
a.
Accordingly, the stock dish
3
containing the micro-balls B is caused to undergo vibration by use of a vibration generator
4
such as a parts feeder or the like, and the the micro-balls B are sent flying as far as the vicinity of the adsorption holes
2
a,
thereby enhancing adsorbability thereof. That is, the stock dish
3
provided with the vibration generator
4
serves as ball feeding means for carrying the micro-balls B to the adsorption holes
2
a.
Now, the adsorption unit described above is to cause the micro-balls B to be floated through vibration of the stock dish
3
with the use of the vibration generator
4
, however, this is not a case where the micro-balls B are sent flying towards all of the adsorption holes
2
a
at a uniform density. Accordingly, there is a risk that an excessive number of the micro-balls B are adsorbed to some of the adsorption holes
2
a
on one hand, and none of the micro-balls B is adsorbed to some of the adsorption holes
2
a
on the other hand.
Furthermore, when the adsorption head
1
sucks in the micro-balls B out of the stock dish
3
, and holds the same, one each of the micro-balls B is desirably held by the respective adsorption holes
2
a.
However, it has been observed that an excess of the micro-balls sticks between the adjacent micro-balls B normally held by the adsorption jig
2
, or the excess of the micro-balls sticks to the micro-balls B themselves normally held by the adsorption jig
2
, in a condition resembling hanging icicles.
For that reason, it has been in practice that one each of the micro-balls B is fed into the respective adsorption holes
2
a
of the adsorption jig
2
by use of a filter for removal of the excess of the micro-balls B, provided with holes, each large enough to allow only one of the micro-balls B to pass therethrough, formed at positions corresponding to the respective adsorption holes
2
a
of the adsorption jig
2
. However, this will require a complex mechanism for aligning the adsorption jig
2
with the filter for removal of the excess of the micro-balls B.
Taking into consideration the problem described above, the inventor has developed a system wherein with the use of a ball feeding unit having an arraying jig provided with array holes to which the micro-balls B are adsorbable, formed at positions corresponding to the respective adsorption holes
2
a
of the adsorption jig
2
, the micro-balls B are lined up opposite to the array holes formed in the arraying jig of the ball feeding unit to enable the micro-balls B in the arraying jig to be delivered to the adsorption jig
2
. With the system, the micro-balls B can be adsorbed efficiently one by one to the respective adsorption holes
2
a
of the adsorption jig
2
.
Even with this system, however, there have been cases where the excess of the micro-balls B is stuck to the array holes of the arraying jig, so that the micro-balls B are excessively fed to the adsorption holes
2
a
of the adsorption jig
2
, and adsorbed thereto.
SUMMARY OF THE INVENTION
In view of the circumstance described above, the present invention has been developed, and an object of the invention is to provide a method of lining up micro-balls in a micro-ball mounting apparatus of a semiconductor device manufacturing system, whereby micro-balls to be formed into bumps can be distributed and lined up on an arraying jig, having a plurality of array holes, without an excess of the micro-balls sticking thereto, and without causing an increase in cost.
To this end, in accordance with a first aspect of the invention, there is provided a method of lining up micro-balls whereby the micro-balls to be formed into bumps are lined up on an arraying jig, the micro-balls lined up are adsorbed to an adsorption jig, and prior to mounting the micro-balls adsorbed on a work, the micro-balls are adsorbed to the adsorption jig of an adsorption head; the method comprising: a micro-ball adsorption step for causing the micro-balls to be adsorbed to a plurality of array holes by supplying the micro-balls onto the arraying jig having the plurality of the array holes formed therein, and by sucking in air through the array holes, a micro-ball distribution step for distributing the micro-balls placed on the arraying jig into the respective array holes, and an excessive micro-ball removal step for removing an excess of the micro-balls, sticking to the arraying jig, wherein, in the excessive micro-ball removal step, a cylindrical body in the shape of a cylinder is disposed on the arraying jig, a standing wave having nodes thereof, formed concentrically, is generated inside the cylindrical body by subjecting the cylindrical body to ultrasonic vibration, and the excess of the micro-balls, sticking to the top of the arraying jig, is concentrated at the nodes of the standing wave before removal by moving the cylindrical body horizontally over the arraying jig.
Thus, since the cylindrical body in the shape of a cylinder is disposed on the arraying jig after the micro-balls are supplied to and adsorbed to the top of the arraying jig, the standing wave having nodes thereof, formed concentrically, is generated inside the cylindrical body by subjecting the cylindrical body to ultrasonic vibration, and the excess of the micro-balls, sticking to the top of the arraying jig, is concentrated at the nodes of the standing wave before removal by moving the cylindrical body horizontally over the arraying jig while maintaining the above-mentioned condition of the cylindrical body, the micro-balls can be lined up properly by ensuring removal of the excess of the micro-balls, sticking to the arraying jig.
As a result, the micro-balls lined up on the arraying jig can be adsorbed to the adsorption jig, and can be mounted on a work with certainty.
Further, in the first aspect of the invention, the cylindrical body may be formed in the shape of a bottomed cylinde
Ando Electric Co. Ltd.
Bowers Charles
Flynn ,Thiel, Boutell & Tanis, P.C.
Lee Hsien-Ming
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