Material or article handling – Apparatus for charging a load holding or supporting element... – Supply source capable of 360 degrees revolution
Reexamination Certificate
1999-02-11
2001-10-02
Olszewski, Robert P. (Department: 2167)
Material or article handling
Apparatus for charging a load holding or supporting element...
Supply source capable of 360 degrees revolution
C414S222010, C414S331010, C414S731000, C198S339100, C198S469100, C198S475100
Reexamination Certificate
active
06296434
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a product supply unit to be used in manufacturing and assembling a product, such as a semiconductor device.
BACKGROUND OF THE INVENTION
Conventionally, to supply a product just after manufacturing from a stock position to a work position and to stock the product at another position after working are automated by a product supply unit.
Conventional product supply units are explained below, referring to
FIGS. 1 and 2
.
FIG. 1
is an illustration showing the principle of operation in an example of conventional product supply unit. As shown, the conventional product supply unit uses pick and place mechanisms (hereinafter referred to as ‘P/P mechanism’)
101
,
102
where a cam or ball screw and a slide mechanism are combined. In conducting the supply operation or stock operation of a product by these mechanisms, by reciprocating a product holding nozzle, the product is supplied from a supply-side product receiver
110
to a product processing position
100
, or is supplied from the product processing position
100
to a stock-side product receiver
210
.
FIG. 2
is an illustration showing the principle of operation in another example of conventional product supply unit disclosed in Japanese patent application laid-open No. 62-79136 (1987). In this example, a link mechanism is used. With this link mechanism, where a support
520
is disposed between members
510
and
500
attached to rotational center shafts
511
and
501
, respectively and coupling shafts
512
,
502
compose a pair of parallel links, the rotational center shaft
512
is rotated by a driving motor
530
through a power transmission belt
540
, thereby picking up a product
560
from a magazine
550
disposed at the lowermost position of the support
520
, further rotated to supply it to carrier roller
570
side.
However, in the conventional product supply unit in
FIG. 1
, there is a problem that the operation time is long. The first reason is that, since the supply and stock of product is conduct by the reciprocating operation and therefore only the product holding nozzle returns on the return way while conducting the lost motion with no supply and stock of product, the operation time is wasted by that much. The second reason is that in the supply operation, the up/down motion of the product holding nozzle for holding the product at the supply-side receiver
110
and the up/down motion of the product holding nozzle at the product processing position
100
, and in the stock operation, the up/down motion of the product holding nozzle at the stock-side product receiver
210
are all alternately performed, therefore the operation time is consumed in each of the motions.
Also, in the conventional product supply unit in
FIG. 2
, there is a first problem that the rotation operation lacks smoothness. The reason is that, when the pair of links align at the uppermost and lowermost positions of the support, the dead point, which is the worst weakness of link mechanisms, occurs and the rotation operation is thereby obstructed. Also, there is a second problem that the precision is significantly lowered at the work position that is assigned to the lowermost position of the support. The reason is that the dead point occurred causes the most unstable structure state of the link mechanism.
On the other hand, the product supply unit may be also used to automate the electrical characteristic test or burn-in test of a semiconductor product. For example, in case of electrical characteristic test, the product is supplied from the supply tray to the contact pin on the measurement box of IC tester, then measured while being pressed at a given contact pressure. After the measurement, the product is selected and stocked at a given place based on the test result. Thus, from the supply until stock of the product, it is automatically conveyed by the product supply unit.
The measurement box where the IC tester and the measured product are mounted has been scaled up with the recent functional enhancement of semiconductor product. For example, when the P/P mechanism is simply used, a stocker (tray elevator)
701
for the supply or stock of a product
700
, as shown in
FIG. 3
, needs to be disposed at the circumference in the plane direction of a measurement box
702
due to the stock amount. Therefore, the distance between the stocker
701
and a measurement contact
703
becomes long and the operation time taken between the stocker
701
and the measurement contact
703
becomes long. Also, the floor area occupied by the unit is large. To shorten the operation time, it can be thought that multiple carrier mechanisms are provided such that they relay the distance between the stocker
701
and the measurement contact
703
and the moving distance assigned to each carrier mechanism is shortened, and the moving speed in the horizontal direction of each carrier mechanism is speeded up. In this case, each carrier mechanism may include not only the P/P mechanism but also a carrier mechanism using a rotary table. However, in such unit composition, the cost of unit must be increased since the number of components increases. Also, there is a problem that the floor area occupied by the unit remains large and thus the outer area of the unit cannot be decreased.
To solve this problem, there is a technique that the stocker
701
is, as shown in
FIG. 4
, overlaid on the measurement box
702
and a tray
704
is taken out from the bottom of the stocker
701
to supply or stock the product
700
through the tray
704
. However, even in this case, the outer area of the unit cannot be decreased since the stage area for mounting the tray
704
to be taken out from the stocker
701
is necessary.
So, as shown in
FIG. 5
, to realize a mechanism that the product
700
is supplied and stocked directly between the tray
704
on the top of the stocker
701
overlaid on the measurement box
702
and the measurement contact
703
is most effective for shortening the operation time and for decreasing the outer area of unit. In such composition, it is necessary to move the product a distance along the drop height from the top of the stocker to the measurement box lying under the stoker. Hereupon, when the P/P mechanism is used for this transportation, the product is, at a stroke, moved the distance along the drop height by the single mechanism. Therefore, the operation distance for the single mechanism becomes long and the operation time on the forward way becomes very wasteful. Also, when the rotary link mechanism in
FIG. 2
is used instead of the P/P mechanism, the position precision of product is significantly lowered at a position where the product support comes to the measurement point at the lowermost, thereby causing an error in measurement.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a compact product supply unit that can realize high-precision, efficient and fast transportation.
According to the invention, a product supply unit, comprising:
a first plate member with a first rotational center shaft;
a second plate member with a second rotational center shaft, the second plate member being disposed opposed to the first plate member;
a plurality of supports disposed, at an equal pitch, on the circumference centered with the first rotational center shaft between the first plate member and the second plate member, and coupled with the first plate member with a first coupling shaft and with the second plate member with a second coupling shaft; and
means for holding a product, the product holding means being provided on each of the plurality of supports.
REFERENCES:
patent: 3965647 (1976-06-01), Sjoman
patent: 4184420 (1980-01-01), Podaras et al.
patent: 4476649 (1984-10-01), Zaruba
patent: 4526134 (1985-07-01), Sapp
patent: 4639968 (1987-02-01), McKibben et al.
patent: 4960275 (1990-10-01), Magon
patent: 5039180 (1991-08-01), Lemons
patent: 5054155 (1991-10-01), McKibben et al.
patent: 5076210 (1991-12-01), Horn
patent: 5370247 (1994-12-01), Handleman
patent: 5421318 (1995
NEC Corporation
O'Connor Gerald J.
Olszewski Robert P.
Sughrue Mion Zinn Macpeak & Seas, PLLC
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