Fluid handling – With casing – support – protector or static constructional... – Guards and shields
Reexamination Certificate
1999-12-30
2001-02-27
Chambers, A. Michael (Department: 3753)
Fluid handling
With casing, support, protector or static constructional...
Guards and shields
C137S377000, C137S315110, C137S315010, C312S350000, C312S237000
Reexamination Certificate
active
06192919
ABSTRACT:
BACKGROUND OF INVENTION
This invention relates to shipping crates for chemicals such as tetraethylorthosilicate (“TEOS”) which is used in integrated circuit fabrication.
In the semiconductor industry, a variety of chemicals are employed during the fabrication of integrated circuits. For example, TEOS is widely used as a feed stock to a plasma enhanced reactor which forms silicon dioxide layers. Such chemicals are often shipped in bulk delivery tanks, such as 200 liter canisters. When filled, these tanks can be quite heavy; for example, filled tanks may weigh 600 pounds or more. As a result, forklifts have previously been used to move filled tanks, including use of forklifts when placing the filled canister in a storage and delivery cabinet. However, use of a forklift is prone to difficulties, such as potential rupture of the vessel, difficulty of loading such tanks in narrow walkways, lack of access in cleanrooms, and so forth.
The tanks have been housed in delivery cabinets. The delivery cabinets include hardware for attached to the tanks, and for withdrawing chemicals from the tanks and sending the withdrawn chemicals to a delivery point, typically a smaller delivery canister. Prior cabinets functioned as containment vessels. The cabinets have heretofore been oversized so that a spill may collect in the bottom of the cabinet. For instance, a grating is typically installed to act as a false floor, with the tank resting on the grating. The grating permits liquid spills to run into the reservoir in the bottom of the cabinet. A chemical spill in a conventional cabinet is, however, problematic for several reasons. For instance, the cabinet itself must be taken off line so that it can be cleaned. As a result, supply of chemical from the contaminated cabinet is foreclosed during clean-up. Such down time of the supply cabinet may result in temporary shut down of the process equipment utilizing the cabinet for chemical supply. For bulk cabinets of this size, up to 30 systems could be potentially be down, which would be very costly event during integrated circuit fabrication.
Furthermore, because the cabinet is oversized as protection in the event of a spill, the cabinets may take up more space than would otherwise be desirable. Since space is valuable in any fabrication operation, a system which enables containment of spills but which has a smaller size would be highly desirable. Likewise, since prior bulk cabinets included the aforementioned grating, the bulk tanks needed to be lifted for placement in the cabinet.
SUMMARY OF INVENTION
The present invention provides a solution to one or more of the disadvantages and deficiencies described above. In particular, this invention provides a combination shipping/containment crate (or “cart”), which facilitates use of a storage and delivery cabinet of reduced size in comparison to conventional cabinets used in the semiconductor industry. One significant advantage to this invention is that the cart of this invention may be transported readily into narrow, crowded chemical storage areas, and into cleanroom areas. In one broad respect, this invention is a shipping cart, comprising: a base having four sides, wheels attached to the base, a top attached to the sides having a tank hole, wherein the base and sides have been attached to provide a sealed compartment.
In another broad respect, this invention is a chemical refill system, comprising a tank housed in a crate, wherein the crate comprises a base having four sides, wheels attached to the base, a top attached to the sides having a tank hole, wherein the top has been fastened to the sides such that the tank hole fits over a vertical sheath on the tank, wherein the base and doors have been attached to provide a sealed compartment. In one embodiment of this invention, the system is placed in the chemical delivery cabinet.
In another broad respect, this invention is a chemical delivery cabinet, comprising: a base, three sides, and one or more doors attached to one or more sides, a valve manifold affixed to an inner wall of the cabinet, process control instrumentation which connects to and controls the valve manifold, wherein at least one of the doors has a touch control pad mounted thereon.
In yet another broad respect, this invention is a process useful for supplying a refill tank, comprising: providing a crate which comprises a base having four sides, wheels attached to the base, a top attached to the sides having a tank hole, wherein the top has been fastened to the sides such that the tank hole fits over a vertical sheath on the tank, wherein the base and sides have been attached to provide a sealed compartment; providing a tank; placing the tank in the crate with the tank hole fitting over a vertical sheath of the tank; filling the tank with a liquid chemical before or after placing the tank in the crate.
This invention has a number of advantages. For example, the shipping crate of this invention facilitates easy maneuvering and installation of a filled tank in a refill cabinet. Advantageously, the shipping cart may even be maneuvered into a cleanroom. Hence, widened aisles and the like previously required in order to place a refill tank in a refill cabinet are rendered unnecessary in view of this invention. Advantageously, the crate is adapted to function as a self-containment vessel in the event of a chemical leak or spill from the tank. More advantageously, since the shipping crate functions as a self-containment vessel, the cabinet housing the valve manifold and lines can be reduced in size, thereby saving space in a manufacturing operation. Furthermore, if a spill or leak should occur, the tank may be readily drained and changed out by simply withdrawing the shipping crate from the cabinet, and installing a new crate, thereby effectively eliminating down time in the manufacturing process.
REFERENCES:
patent: 5255821 (1993-10-01), Hall et al.
patent: 5381902 (1995-01-01), Dumser et al.
patent: 5921270 (1999-07-01), McCarty
patent: 6041812 (2000-03-01), Hilbers
Esser Craig
Gregg John N.
Jackson Robert M.
Serdahl Eric
Advanced Delivery & Chemical Systems Ltd.
Chambers A. Michael
McShane Thomas L.
O'Keefe, Egan & Peterman
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