Material or article handling – Apparatus for moving material between zones having different...
Reexamination Certificate
1999-03-31
2001-02-13
Bratlie, Steven A. (Department: 3652)
Material or article handling
Apparatus for moving material between zones having different...
C414S939000, C414S940000
Reexamination Certificate
active
06186723
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a load port for semiconductor manufacturing equipment used in the production of semiconductors, semiconductor devices, and the like. This application is based on the patent application No. Hei 10-91972, filed in Japan, the content of which is incorporated herein by reference.
2. Description of the Related Art
In order to manufacture high quality semiconductor devices in an economical manner, there has been a trend towards increasing the size of the wafer diameter. For example, a front-opening unified pod (FOUP) type carrier
11
, shown in
FIG. 7
(the embodiment in the figure displays a FOUP carrier with its cover removed), an open cassette (OC) type carrier
11
, shown in
FIG. 8
, and the like, are being used as carriers for transporting wafers in semiconductor manufacturing equipment which handle wafers possessing diameters greater than 300 mm.
The peripheral structure of a load port in conventional semiconductor manufacturing equipment is typically described in FIG.
9
. In
FIG. 9
, a wafer
12
, accommodated in a carrier
11
for wafers (hereinafter, referred to as carrier
11
), such as an FOUP carrier shown in
FIG. 7
, and the like, is transported to a load port for processing wafers in semiconductor manufacturing equipment
13
(hereinafter, referred to as equipment
13
), either manually or by an automated transporter, and loaded onto a movable, carrier base
14
, which is stationed at the load port. Additionally, an opening
16
for the wafer
12
is provided in the equipment
13
. The opening
16
is usually closed with a cover
15
(described below). When the cover
15
is opened, it is possible to move the wafer
12
in and out between the carrier
11
and the equipment
13
through the aforementioned opening
16
, or alternatively store the wafer
12
together with the carrier
11
inside the equipment
13
through the opening
16
.
The carrier
11
, which has been transported to the load port, is loaded onto a carrier base
14
, which has been positioned in front of the opening
16
. This carrier base
14
can move further away from, as well as towards the opening
16
. The carrier
11
is loaded onto the carrier base
14
at a position that is a short distance away from opening
16
, and is transported towards the opening
16
, together with the carrier base
14
. In general, with respect to a FOUP carrier, the cover
15
of the opening
16
is designed to open with carrier
11
, loaded onto the carrier base
14
, pushed against the front surface of the equipment
13
. Thereafter, the wafer
12
housed within the carrier
11
is removed.
The force of pushing the carrier
11
against the front surface of the equipment
13
is set to a minimum. However, since a positive pressure exists within the equipment
13
to prevent dust from entering, the force of carrier exerted against the front surface of the equipment must be at least large enough to overcome this pressure. For example, if the equipment
13
possesses an inner capacity of 50 mm of water, and a FOUP (i.e., carrier
11
), accommodating 25 sheets of wafers
12
, possesses a projected surface area against the equipment
13
of 300 mm×350 mm, a force of at least 5.25 kg is required to push the carrier
11
against the equipment
13
. Furthermore, in the case when, in order to prevent oxidation of the wafer
12
, the interior of the equipment
13
is filled with an inert gas such as nitrogen, argon, dry air, or the like, a sealing material is required in between the equipment
13
and the carrier
11
to prevent this gas from leaking. In such a case, the carrier
11
pushes up against the equipment
13
through this sealing material, and thus a greater force is required.
Thus, in order to obtain the aforementioned required force, a device that possesses the capability of generating this force is used as an actuator for moving the carrier
11
. Therefore, in the case when the carrier
11
is transported towards the opening
16
, the actuator continuously operates, driving the carrier
11
against the opening
16
with the required force.
However, the aforementioned force is actually required only during the final step, and is not necessary throughout the entire process. Moreover, when the carrier
11
is transported together with the carrier base
14
using an excessively large force, extreme caution must be maintained during operation, as a substantial risk of injury exists via a projection or the like, in such cases as when a hand is caught in between the carrier
11
and the equipment
13
during transportation. In addition, for the same reasons, extreme caution must be exercised, not only while pushing the carrier
11
against the opening
16
, but also when closing the opening
16
with the cover
15
using a large force.
In consideration of the above problems, it is an object of the present invention to provide a load port that possesses a highly safe structure in order to prevent injuries due to a lack of caution.
SUMMARY OF THE INVENTION
A load port according to the present invention comprising a transporting means and/or a moving means for respectively transporting a carrier base and moving a cover, using a smaller force until the carrier base and/or the cover reaches a predetermined position that is a predetermined distance from an opening, where it is no longer possible to catch a hand or the like between the carrier base or cover and the semiconductor equipment. Then, the carrier base and/or the cover is transported or moved towards the opening, the transporting means and/or moving means respectively transporting the carrier base and/or moving the cover, towards the opening to completely close the opening using a larger force.
REFERENCES:
patent: 4042128 (1977-08-01), Shrader
patent: 4169538 (1979-10-01), Bird et al.
patent: 4698938 (1987-10-01), Huber
patent: 4918864 (1990-04-01), Lunenschloss et al.
patent: 5364219 (1994-11-01), Takahashi et al.
patent: 5829939 (1998-11-01), Iwai et al.
patent: 4123430 (1992-04-01), None
Matsushima Keiichi
Murata Masanao
Nanpei Zenta
Oyobe Hiroyuki
Saeki Hiroaki
Bratlie Steven A.
Darby & Darby
Shinko Electric Co. Ltd.
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