US20060283770A1

US20060283770A1 - Transportation fixture and package for substrate rack

Info

Publication number: US20060283770A1
Application number: US11/144,870
Authority: US
Inventors: Ronald Schauer
Original assignee: Applied Materials Inc
Current assignee: Applied Materials Inc
Priority date: 2005-06-03
Filing date: 2005-06-03
Publication date: 2006-12-21
Also published as: JP3134131U; JP3134448U; CN201132651Y; TWM319516U; CN200986915Y; CN201144053Y; JP3134447U

Abstract

A transportation fixture for holding a substrate rack comprises top and bottom endplates that are attached by a plurality of posts. The posts are spaced apart a sufficient distance to confine a substrate rack between the posts. Each post has a longitudinal inside edge with a compliant bumper that cushions the substrate rack. A transportation shell at least a portion of which is light permeable, can enclose the fixture to allow viewing of the fixture and rack, without opening the shell. An exterior hard casing can enclose the shell for further protection.

Description

BACKGROUND

Embodiments of the present invention relate to a transportation fixture and package to transport a substrate rack.
A substrate rack can be used to hold a batch of substrates during fabrication of the substrates to form display panels and semiconductors. For example, a substrate rack, such as a wafer processing boat, has a series of vertically positioned slots that can each hold a semiconductor wafer. An exemplary substrate rack 10 that can hold semiconductor wafers in a deposition chamber is illustrated in FIG. 1. The substrate rack 10 comprises a plurality of graphite disks 20 that are separated by spacers 30 and held together by metal rods 40 that pass through the spacers 30 to connect to a base plate 50 and top plate 60. The rack components 20, 30, 40 and 50 may be coated with a ceramic, such as silicon carbide, to protect them from the deposition environment, and to prevent contaminants from the substrate rack 10 from entering the substrate processing chamber. The substrate rack 10 can be placed in a deposition chamber, such as a chemical vapor deposition (CVD) chamber, for depositing materials such as polysilicon, amorphous silicon or silicon dioxide, on the stack of substrates. In this process, a silicon containing gas is introduced into the CVD chamber and a plasma is generated while the substrate rack 10 is rotated and heated. While an exemplary substrate rack is used to illustrate such racks, it should be understood that substrate racks used in other substrate processing apparatus or methods, such as for example, physical vapor deposition chamber (PVD), etch chambers and implant chambers, can also be used.
In use, after several process cycles, the rack 10 is cleaned or reconditioned to remove accumulated process deposits. For example, in a typical CVD process, the CVD material deposited on the substrate also deposits on the substrate rack 10. After a number of CVD process cycles, a layer of CVD material builds up on the substrate rack 10. This built up layer of deposits can contaminate the CVD chamber and the substrates if the deposits flake off the substrate rack. Accordingly, the deposited materials are periodically removed from the substrate rack 10 to recondition and clean the substrate rack for use in further process cycles.
Typically, the substrate rack is packaged and shipped to an off-site cleaning facility for cleaning or reconditioning of the rack 10. However, there are several problems with transportation of the rack 10. First, the assembled substrate rack is heavy often weighing between about 50 to 100 pounds and yet fragile which makes it difficult to ship without breakage. Also, the rack 10 is sensitive to the ambient environment and can erode or corrode when exposed to air. Also, the deposits formed on the rack 10 can be toxic or hazardous to handlers. Thus, prior to being shipped to the cleaning site, a thin sealing layer, typically comprising non-doped silicon, is deposited on the substrate rack 10 to protect handlers from exposure to the deposits on the rack. The substrate rack 10 is then wrapped in air-cushioned “bubble-wrap” and placed into a wooden crate for shipping. Because the substrate rack 10 is extremely fragile, it must be transported in one position, i.e., with its longitudinal axis in the vertical direction; otherwise, the brittle components of the substrate rack can chip or break. All of these solutions to the transportation problem add to the cost of cleaning and reconditioning the rack 10.
In transit to the cleaning site, the crate containing the substrate rack 10 may be subjected to inspection by immigration or law enforcement officers. To perform the inspection, the officer typically opens the crate and removes the bubble-wrap to ensure that contraband is not contained in the crate. After inspection, the substrate rack 10 is re-packaged and transported to the cleaning site. There, the substrate rack is placed in an acid bath for a few hours to remove the layer of deposited materials. Up to this time, the substrate rack 10 is assembled because the layer of deposited materials glues the components of the substrate rack together, and the substrate rack cannot be disassembled without damaging the components. After the first acid bath, the layer is removed and the components of the substrate rack become “unglued.” The substrate rack 10 is then disassembled, cleaned again, and baked dried at approximately 400° C. for about ten (10) hours. Once dried, the disassembled reconditioned components are packaged and shipped back to the customer site, where the substrate rack 10 is reassembled and ready for use.
During the above-described transportation and reconditioning process, a large percentage of substrate racks 10 are irreparably damaged. For example, when the substrate rack 10 is packaged, i.e., wrapped in bubble-wrap and placed in the crate, unpacked, or repackaged, e.g., at the customer site, during inspection and at the cleaning site, the silicon carbide coat on the components of the substrate rack 10 can be easily chipped or broken, rendering the components useless. If the crate is tilted or dropped during transport, the fragile components can break or chip. The substrate rack 10 can be damaged at the customer site when it is being reassembled by lab technicians who are typically inexperienced and unskilled in reassembling the substrate rack. In addition to damaging the substrate rack, handlers and/or inspection officers can be exposed to toxic materials beneath the thin sealing layer when the components are broken or chipped.
Thus, it is desirable to be able to efficiently transport a substrate rack 10 from a clean room to a cleaning or off-site facility for cleaning or reconditioning. It is also desirable to minimize breakage of the substrate rack 10 during the packing, unpacking, and transportation processes. It is further desirable to efficiently clean the rack 10 without damaging the components. It is further desirable to protect handlers from exposure to the deposits on the rack during handling and transportation.

SUMMARY

A transportation fixture for holding a substrate rack comprises top and bottom endplates. A plurality of posts attach the top endplate to the bottom endplate and are spaced apart a sufficient distance to confine the substrate rack therebetween. Each post has a longitudinal inside edge. A compliant bumper is coupled to each longitudinal inside edge of the posts. The transportation fixture cushions, secures and protects the substrate rack during transportation.
In another embodiment, the transportation fixture comprises top and bottom endplates that are triangular and have apexes. Three posts attach the apexes of the top endplate to the apexes of the bottom endplate. A compliant bumper is coupled to each post.
A shell having at least a portion which is light permeable, can also enclose the fixture to protect the substrate rack from the external environment while still allowing viewing of the fixture and rack without opening the shell. In one version, the shell comprises a first tray having a closed end and an open end with a first circumferential lip, at least a portion of the first tray comprising a light permeable material. A second tray comprises a closed end and an open end with a second circumferential lip, at least a portion of the second tray comprising a light permeable material. The first and second circumferential lips mate so that the open ends of the first and second trays face each other to form a cavity therebetween. A sealing gasket can be used between the circumferential lips to form a seal. The shell can also include exhaust port and purge gas couplings for evacuating the shell and filling the shell with a non-reactive gas, respectively. The shell allows customs or other visual inspections of the fixture and rack that would otherwise require opening the shell to view its internal contents.
A transportation casing can also be used to enclose the shell for shipping. The transportation casing comprises a rigid box having an interior foam block that is contoured to match the shape of the shell. The casing provides additional mechanical protection during transportation.

DRAWINGS

These features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings, which illustrate examples of the invention. However, it is to be understood that each of the features can be used in the invention in general, not merely in the context of the particular drawings, and the invention includes any combination of these features, where:
FIG. 1 (PRIOR ART) is a perspective view of an embodiment of a substrate rack;
FIG. 2 is a perspective view of an embodiment of a transportation fixture for the substrate rack of FIG. 1;
FIG. 3 is a perspective view of the transportation fixture of FIG. 2 enclosing the substrate rack of FIG. 1;
FIG. 4 is an exploded perspective view of the transportation fixture of FIG. 2;
FIG. 5 is a perspective view of an embodiment of a transportation fixture according to another version of the present invention;
FIG. 6 is a perspective view of an embodiment of a shell enclosing a transportation fixture and also showing a hard casing having a foam interior to receive the shell;
FIG. 7 is a perspective view of another embodiment of a shell shown enclosing a transportation fixture and showing a detail of a fastener used to join the trays of the sherll;
FIG. 8 is a perspective view of yet another embodiment of the shell shown enclosing a transportation fixture;
FIG. 9 is a sectional side view of an embodiment of a shell having an exhaust port and a purge gas port;
FIG. 10A is a sectional side view of the exhaust port coupling of the shell of FIG. 9; and
FIG. 10B is a sectional side view of another embodiment of the exhaust port coupling;
FIG. 11 is a sectional side view of the purge gas port coupling of the shell of FIG. 9; and
FIGS. 12A and 12B are perspective side views of a hard casing suitable for transporting the shell.

DESCRIPTION

A transportation package comprising a transportation fixture can be used to transport a substrate rack 10, as shown in FIG. 1, from one chamber to another or from one facility to another. For example, the transportation package can be used to transport the rack 10 for cleaning or reconditioning in a suitable facility after use of the rack in a deposition chamber. The transportation package serves as a protective container for the transportation fixture during shipping and handling, and can also be used for other fixtures than those illustrated herein. The transportation fixture can also be used to hold the fragile rack 10 during the reconditioning processing, e.g., during packing and unpacking, while in acid or other cleaning baths and in drying ovens or furnaces. The transportation fixture can be used to hold the substrate rack 10 within the transportation package or to transfer the 10 rack to another room in the same building. Both the transportation package and fixture can also be used to transport racks other than the exemplary rack 10 illustrated herein, with suitable modifications as would be apparent to those of ordinary skill in the art. Thus, the scope of the present invention should not be limited to the illustrative embodiments of the transportation package, fixture and rack described herein.
An exemplary transportation fixture 200 for holding the substrate rack 10 is illustrated in FIG. 2. In one version, the substrate rack 10 is enclosed and protected by the transportation fixture 200. The transportation fixture 200 is reusable and can also be used to return a fully reassembled substrate rack 10 to the customer. The transportation fixture 200 comprises top 210 a and bottom 210 b endplates that are attached to one another by a plurality of posts 220. The endplates 210 a, 210 b and the posts 220 form an enclosure that confines the substrate rack 10 as shown in FIG. 3. The endplates 210 a, 210 b and posts 220 may be manufactured from a chemically-inert non-metallic and temperature-resistant material, such as, for example, polytetrafluoroethylene PTFE (commercially known as Teflon®) so that the transportation fixture 200 can withstand the cleaning or reconditioning process and also be used to return the reconditioned and reassembled substrate rack 10.
In one version, the bottom endplate 210 b includes a skid plate 230 that prevents the substrate rack 10 from slipping off of the fixture 200 during the loading and unloading process. The endplates 210 a, 210 b can also have raised bumps (not shown), shaped as ribs, islands, mesas or ridges, that are located on the surface 232 facing the stack 10 to prevent contact between the substrate rack 10 and the endplates 210 a, 210 b, when the rack 10 has protruding end portions (also not shown). The raised bumps also assist in maintaining the rack 10 in a vertical position while the substrate rack 10 is loaded and unloaded. The raised bumps can be either coupled to, or integrally formed on, the surface of the endplates 210 a, 210 b.
Each endplate 210 a, 210 b can include reinforcing structures 240, such as blocks, brackets or gussets, to increase the rigidity of the endplate 210 a, 210 b and to provide other functions, such as a means for lifting and holding the transportation fixture 200. For example, the reinforcing structures 240 can include holes 243 that can serve as finger-holds or means for attaching grips or other carrying straps. Like the raised portions 230, the reinforcing structures 240 can be either coupled to, or integrally formed on, the endplates 210 a, 210 b. Moreover, the endplates 210 a, 210 b can provide openings 250 to facilitate the flow of a cleaning solution, i.e., acid, over the substrate rack 10 components.
The posts 220 a-c coupling the endplates 210 a, 210 b are positioned such that the substrate rack 10 is securely held between the posts 220 a-c, as is shown in FIG. 3. In one version, the endplates 210 a, 210 b are triangular in shape and of sufficient size to support the substrate rack 10. The triangular shape requires less material to provide the same support and consumes less space thereby allowing more endplates 210 a, 210 b to be shipped in one container.
Referring to FIG. 4, when the endplates 210 a, 210 b are triangular, the endplates 210 a, 210 b have apexes 212 a-f, and the posts 220 a-c can be joined to the apexes 212 a-f of the triangular endplates 210 a, 210 b to maximize the space between the posts 220 a-c. The triangular top and bottom endplates 210 a, 210 b can also have slots 214 a-f at their apexes 212 a-f sized to receive the posts 220 a-c. However, in versions where the endplates 210 a, 210 b are not triangular, the slots 214 a-f can be located at corners and/or edges.
As shown, in this version, each of the posts 220 a, 220 b, 220 c are made from a pair of joined strips 222 a,b 222 c,d and 222 e,f respectively. The strips 222 a,c,e each have an inside surface 224 a,c,e that contacts an inside surface 224 b,d,f of the other strips 222 b,d,f. Each strip 222 a-f also has a longitudinal groove 226 a-f along the inside edge 228 a-f respectively. When the longitudinal grooves 226 a-f are aligned with one another, they join to form an internal channel into which a reinforcing rod 232 can be positioned. In one version, the reinforcing rod 232 strengthens the post 220 and can be a stainless steel rod. Because the reinforcing rod 232 is at least partially enclosed by the channel, it is protected from the corrosive solutions used during the reconditioning process. To ensure this protection, the strips 222 can be joined together by a conventional inert, heat-resistant sealant, such as a ceramic or epoxy sealant.
As is shown, each strip 222 has an inside longitudinal edge 228 a-f that faces the interior of the fixture 200, i.e., toward the substrate rack 10. The longitudinal edges 228 can be narrow (as shown) or wide (not shown). In one version, the longitudinal edge 228 a-f is receives a compliant bumper 234 a-c along the joined longitudinal edges 222 b. By cupping the inside longitudinal edges 228 the compliant bumpers 234 are securely attached. In one version, the bumper 234 can be attached via stainless steel screws that are sealed with a high temperature silicone sealant. Thus, servicing and replacement of the bumper 234 is simplified. In another version, the longitudinal edges 228 can be substantially straight and the compliant bumpers 234 attached to the longitudinal edges 228 by a chemically inert, heat-resistant adhesive. In one version, the compliant bumpers 234 can be a polymer tubing, such as low durometer rubber that is sealed at its open ends, an elastomer strip, or a strip made from another compliant non-absorbent chemically inert material. In another version, the bumpers 234 can include ridges or other texture to secure the disks 20. In another version, the bumpers 234 can be pneumatic bladders that hold and cushion the substrate rack 10. The fixture 200 with the posts 220 and compliant bumpers 234 secure, protect and cushion the substrate rack 10, in particular, the graphite disks 20. Once the substrate rack 10 is securely loaded into the transportation fixture 200, the compliant bumpers 234 a-c on the posts 220 a-c allow the substrate rack 10 to be placed in any position, e.g., horizontally, without damaging its components.
Referring to FIGS. 2 and 4, the top 210 a and bottom 210 b endplates are attached to one another by the posts 220. At least one of the endplates 210 a, 210 b includes pairs of hinge blocks 242 disposed about at least one of the slots 214 (FIG. 2). The hinge blocks 242 can be either coupled to, or integrally formed on, the endplates 210 a, 210 b. A pair hinge blocks 242 have facing sidewalls that include openings 241 that align with a hole 221 in the post 220. When aligned, a pin 244 is inserted through the openings 241 and the hole 221 to hold the post 220 to the plate 210 a via the hinge blocks 242, as shown in FIG. 4. In one version, each pin 244 can also be coupled to a handle 246 that allows the pin 244 to be inserted or removed easily and also prevents the pin 244 from inadvertently slipping out. Moreover, the handles 246 can be secured to the reinforcing structures 240 via nylon tie wraps (not shown) that are inserted through holes in the reinforcing structures 240 and handles 246, for example. Similar to the endplates 210 a, 210 b and posts 220, the pins 244 and handles 246 can also be manufactured from a chemically inert, heat resistant material, such as PTFE (Teflon). Preferably, the pins 244 are made from Teflon®, which also provides a low friction and low wear hinge axis, as is explained below.
In one version, the pin 244 serves as a hinge such that if the pin 244 connecting one end of the post 220 to one endplate, e.g., the bottom endplate 210 b, is removed, the post 220 can rotate about the pin 244 connecting the other end of the post 220 to the top endplate 210 a. This opens up and allows easy access to the interior of the transportation fixture 200. One or both ends of the post 220 can be hinged in this manner. In addition, one or more posts 220 can be hinged, while others are fixedly attached to the endplates 210 a, 210 b.
The substrate rack 10 can be placed in the transportation fixture 200 directly from the deposition chamber because the transportation fixture 200 is preferably made from a non-metallic, chemically inert and clean material. To facilitize this, one of the endplates, e.g., the top endplate 210 a can be removed completely simply by removing the pins 244 attaching the posts 220 to the top endplate 210 a and by rotating the posts 220 outward to allow the substrate rack 10 to be lowered onto the bottom endplate 210 b of the transportation fixture 200. Then, the posts 220 can be closed and reattached to the top endplate 210 a.
In another version of the transportation fixture 200, the endplates 210 a, 210 b are shaped as a top support frame 710 a at the top of the rack 10 and a bottom support frame 710 b at the bottom of the substrate rack 10, respectively, as shown in FIG. 5. Each support frame 710 a, 710 b includes a flat center hub 712 and a plurality of flat arms 714 extending radially from the center of the hub 712. The angle formed between two adjacent arms 714 depends on the number of flat arms 714. In one version, three (3) flat arms 714 are equally spaced at 120° from one another in a horizontal plane. Each arm 714 includes a slot 716 for receiving and securing the rigid post 220. Although not shown in FIG. 5, each arm 714 can also include the hinge blocks 242 described above to attach the post 220 to the support frame 710 a, 710 b.
The transportation fixture 200 provides rigid support such that the substrate rack 10 is not subjected to torsional or normal forces that can cause breakage when the stack 10 is transported to and from a reconditioning facility. Moreover, because the transportation fixture 200 is made from chemically-inert, non-metallic, and heat-resistant material, the transportation fixture 200 can be placed in the cleaning solution along with the substrate rack 10 and baked at high temperatures without damaging itself, the substrate rack 10, the acid bath, or the oven. Accordingly, the transportation fixture 200 can be used to protect the substrate rack 10 during the reconditioning process until the substrate rack 10 is ready to be disassembled. Further, after the components of the substrate rack 10 have been thoroughly cleaned dried, and reassembled by skilled technicians, the transportation fixture 200 can be reused to transport the fully reconditioned and assembled substrate rack 10 back to the customer. Because the substrate rack 10 is returned assembled, the likelihood of a lab worker breaking the substrate rack 10 while attempting to reassemble the components is reduced.
In one version, the transportation fixture 200 is placed in a shell 800 to form a transportation package 802 that further protect the transportation fixture 200 and the substrate rack 10 during transit. In one embodiment, as shown in FIG. 6, the shell 800 a comprises first and second trays 850, 860, shape as cylinders, which when assembled together, oppose and face each other to form a cavity therebetween. The shell 800 a illustrated herein is only an exemplary embodiment according to the present invention and should not be used to limit the scope of the invention. For example, the trays can also be shaped as rectangular boxes or even as semi-hemispherical domes. The trays 850, 860 are made from a material that is sufficiently rigid to withstand external shocks during transportation. The trays 850, 860 can also include reinforcing features, such as ribs, to stiffen its structure. The trays 850, 860 preferably have a smooth, resilient, and non-granular surface that does not release individual grains when abraded against the surfaces of the transportation fixture 200. Preferably, the surface of the trays 850, 860 is continuous, unbroken and non-porous and is absent individual grains that can flake off when packing or unpacking the transportation fixture 200. In one version, for example, the smooth and resilient surface of the trays 850, 860 can have an rms roughness of less than about 10 microinches. The surface of the trays 850, 860 should also be washable such that contaminants can be wiped away prior to introducing the shell 800 a into a particle-controlled environment.
The assembled pair of trays 850, 860 serve as a self-standing receptacle that encloses the fixture 200 and substrate rack 10, and can even have built-in handles (not shown) to transport the fixture 200 directly into a reconditioning environment or into a clean room. The assembled pair of trays 850, 860 can also be stored for a period of time in the clean room in a sealed and stable environment, and opened only when the substrate rack 10 is needed for immediate use in the process chamber, thereby further reducing any contamination of the substrate rack 10 in the trays 850, 860.
The trays 850, 860 can comprise a continuous circumferential lip 852 a,b that runs around the peripheral circumference of the trays 850, 860. A sealing gasket (not shown) can be placed between the tray lips 852 a,b to provide a tight seal between the assembled trays 850, 860 such that the substrate rack 10 and transportation fixture 200 are protected from contaminants. The circumferential lips 852 a,b reduce the length of gas tight seal needed to seal off the two trays 850, 860. Also, the circumferential lips 852 a,b allow the shell to be positioned vertically when lifting off the top tray 850 to provide access the transportation fixture 200 and rack 10 in the shell 800 a. This version is advantageous when the fixture 200 and rack 10 need to be maintained in a vertical orientation when being placed into or removed from the shell.
Preferably, at least a portion of the shell 800 a is made from a rigid material that is also light permeable to allow visual inspection of the substrate rack 10 that is held inside. As used in this description, light permeable refers to a material that allows at least some wavelengths of light to pass through the material, such as for example, a transparent, translucent, cloudy or partially opaque material. For example, a suitably light permeable material can have a visible light transmission percentage of at least about 20%. The shell 800 a can also be surface polished to enhance the clarity of transmitted light and views. The shell 800 a can also be made entirely from the light permeable material or only a portion of the shell can be made from the light permeable material, such as a window. An inspector should be able to visually examine the internal contents of the bins without breaking open the seals. For example, in one version, only one or more of the trays 850, 860 is made from the light permeable material, however, the entirety of both trays 850, 860 can also be made from the light permeable material. Moreover, the shell 800 a can include markings that indicate the nature of the contents and potential hazards associated with opening with shell 800 a. Such indicia can be provided on the interior surface of the light permeable material of the shell 800 a.
A suitable light permeable rigid material is a heat setting thermoplastic polymer, such as a high density polyethylene, for example polymers that are based on polyethylene terephthalate (PET), glycol-modified PET (PETG), oriented PET (O-PET), or polyethylene naphthalate (PEN), or blends thereof with each other or with other resins. Preferably, the light permeable rigid material is a moldable thermoplastic that softens when heated to form to a mold shape, such as polyethylene terephthalate glycol (PETG), such as PAL-G sheet fabricated by Palram, Ramat Yohanan, Israel. The trays 850, 860 can be molded as a single integral piece using conventional plastic molding techniques from a single blank sheet of thermoplastic material. The blank sheet can be thermoformed into heat-set, thin walled trays utilizing conventional thermoforming methods and equipment such as vacuum assist, air assist, mechanical plug assist or matched mold. A single mold can also be used to make the trays, and portions of the molded trays can be cut off and the cut trays assembled to form a shell having three or more different sections, as shown in FIG. 9.
Advantageously, the shell 800 a allows visual examination of its internal contents without opening the shell or breaking its seal. If the substrate rack 10 is broken or chipped, the breakage can be immediately discovered without opening the shell 800 a in an intermediary transportation point, such as a parts distribution warehouse. It is desirable to inspect the state of the transportation package 802 having the enclosed packaged stack 10 prior to shipment without opening and contaminating the contents of the shell. The shell 800 a also allows customs officers to verify internal contents in accordance with newer, more stringent customs inspections during international transportation across borders, without breaking the seal in a potentially adverse environment, which may cause the stack 10 to be subsequently scrapped upon completing the voyage. The shell 800 a also allows the fragile substrate rack 10 to be safely transported from the clean room to the reconditioning facility and vice versa, while maintaining a good gas tight seal from the external environment.
The transportation package 802 can also include a hard casing 870 which is used to enclose the shell 800 a (or any of the other shell versions described herein) for shipping, as for example, shown in FIGS. 6, 12A and 12B. The casing 870 comprises a box 874 having an interior foam block 876 in has an internal contour or cut-out shaped that matches the external shape of the shell 800 a as shown in FIG. 6. The contoured interior foam block 876 can be made from individual blocks of clean room foam that are bonded to one another to form the requisite cut-out shape. Clean room foam is a highly compressed, spongy, polyethylene foam material, such as for example, Zotefoam's “Plastazote LD-24”, from FP Technologies, Ventura, Calif. Clean room foam typically has an open cellular structure that is porous, for example, with pores sized about 10 to 100 microns.
Typically, the casing 870 is opened outside the clean room, and the shell 800 a containing the transportation fixture 200 with the enclosed stack 10 removed from the casing 870, cleaned if needed, and then carried into the clean room. Because the gases trapped in the pores of the foam block 876 can outgas into the clean room environment; and the bonding layers between the blocks of foam that are used to create the three-dimensional matrix can also outgas or create polymeric contaminant particles, the transportation package is not brought into the clean room.
The box 874 typically comprising a top wall 877, sidewalls 878, and a bottom wall 879, which are all made of rigid material, such as a plastic or metal sheet. Suitable rigid plastics comprise a casing made of molded polypropylene, as for example made by Hardigg Indus., South Deerfield, Mass. The walls 878, 879, 881 of the box 874 can also be reinforced with metal edging 883, for example aluminum edging. The box 874 can also have handles 880 and wheels 882 to facilitate transportation of the packed components from the shipping vehicle to the clean room of a wafer fabrication facility or the refurbishment facility, as shown n FIGS. 12A and 12B.
Other versions of the shell 800 will now be described. In one version, a shell 800 b comprises lips 852 a,b which have troughs that extend parallel to the longitudinal and transverse axes of, as shown in FIG. 7. The transverse lips 852 a,b of the trays 850, 860 can include a plurality of holes 855 through which screws or other fasteners 856 can be inserted to secure the trays 850, 860 to one another. The transverse lips 852 a,b increase the area of contact of the lip seal because the combined distance of the length and width of the shell 800 b is larger that the circumferential distance. Also, the transverse lips 852 a,b allow the shell to removed in the horizontal position, providing lateral access to the internal fixture 200 and rack 10.
Referring to FIG. 8, another embodiment of a shell 800 c for holding a fixture 200 and rack 10, comprises three interlocking trays including a top tray 901, a central tray 902, and a bottom tray 903 that enclose the fixture 200. Each tray 901-903 includes a lip 910 that allows joining the sections 901-903 to one another via fasteners (not shown). In this version, at least one of the circumferential lips 910 also serve as handles for lifting and moving the shell 800 c with its internal contents. The double opening shell 800 c is provided to allow opening the top portion only to allow easier access to the internal contents of the shell. Also, the top portion can have raised reinforcement strips 907 that also serve as feet to support the shell.
Yet another version of the shell 800 d, shown in FIGS. 9 to 11, also comprises three trays 952, 954 and 956, but which are joined together in a different manner. Referring to FIG. 9, the top tray 952 comprises an outer lip 958 that is flat and mates with an inner lip 960 of the second tray 954 that slides into the outer lip 958 to form a gas tight seal. Thus, the upper joint of the shell 800 d is absent an outwardly extending lip. The second tray 954 and third tray 956 are joined by lips 962 and 964 that extend outwardly, and transversely, from of the shell and which have curved end portions 962 a, 964 a, respectively, which provide a grip for holding and moving the shell. The outwardly extending lips 962, 964 allow at least three people to be able to simultaneously lift the shell, as required by current OSHA regulations for packages weighing more than 75 pounds. A seal is formed at the flat inner portions 962 b and 964 b of the lips 962, 964 respectively, using for example, six quarter turn fasteners 951 located at 60° intervals along the lips. In addition, two reinforcing buckets 953 a,b made of the same material as the shell 800 d can be positioned around the top and bottom regions of the shell 800 d to provide extra strength at these regions. In addition, the trays 952, 954, and 956 can all be made form the same mold to save fabrication costs, with portions such as the lip cut off to form three different shapes as shown.
In another version, the shell can also have a recessed cup 974 to house the exhaust port coupling 966 as shown in FIG. 10B. In this version, the recessed cup 974 is sized to fit the exhaust port coupling 966 so that the top plane 975 of the coupling 966 is flush with the top surface 976 of the top wall 967. The recessed cup 974 protects the coupling 966 and prevents accidental knock-off type damage during transportation of the shell 200. The recessed cup 974 is made by molding the cup at the same time as the shell in a conventional mold assembly. In this version, the clamped flange 969 engages a first reinforcement plate 972 mounted on the bottom surface 977 of the top wall 967, and a second reinforcement plate 973 mounted on the top surface 976 of the top wall 967 of the top tray 952.
An exhaust port coupling 966 is located on the top wall 967 of the top tray 952. The exhaust port coupling 966 is large enough to allow insertion of a conventional Draeger gas sampling tube, which can be used to screen the gases in the shell, for example, to detect toxic gases. However, it should also not be too large otherwise it will protrude too far from the top wall 967. FIG. 10A shows an exemplary embodiment of the exhaust port coupling 966 comprising an assembly of (i) an adapter 968, such as a NW-25 adapter; (ii) an O-ring seal 969 with a stainless steel ring; (iii) a blank-off plate 970; and (iv) a clamp shell 971 that clamshell fits around the top of the assembly—all of which are available from Nor-Cal products, Eureka, Calif. The exhaust port coupling 966 allows pumping out of the air or other gas present in the shell by connecting the flange to a typical “house” exhaust scrubbing system of a wafer fabrication or refurbishment facility. The clamped flange 969 engages one or more reinforcement plates 972, 973 that are internally mounted, and bonded to the top wall 967 of the top tray 952. The internally mounted plates 972, 973 are thick and strong to strengthen the joint, and can be for example, a round plate of the same material as the shell (such as polyethylene terephthalate glycol) in a thickness of about 2 to about 20 mm. The various components of the exhaust port coupling 966 can be bonded to one another and to the flange 969 to form a gas tight seal using an adhesive such as McMaster Carr 517A2 PETG adhesive.
A purge gas coupling 980 is located on the sidewall 982 of the bottom tray 956. The purge gas coupling 980 allows a purge gas to be admitted into the shell from an outside purge gas source (not shown). A typical purge gas includes a non-reactive gas, such as nitrogen or argon, and serves to provide an inert or non-reactive environment in the shell 200 to protect the rack 10 from exposure to the external environment. FIG. 10 shows an exemplary embodiment of the purge gas coupling 980 comprising (i) anti-rotation bracket 981 that cannot be easily dislodged in normal service and which is attached by a screw 983; (ii) a conventional VCR type fitting 984; a face seal off plate and gasket 986; and (iv) and a nut 988 to hold the assembly together—all of which are available from Swagelok, Solon, Ohio. An interior gas deflector plate 992 is shaped to deflect the inflow of purge gas downward toward the bottom of the interior of the shell 800 d, as shown by the arrow 994, to prevent the purge gas from impinging directly upon the fixture 200 or rack 10. Blowing purge gas directly onto these parts can dislodge particles and loosen fragile coatings. An externally mounted reinforcement plate 994 is provided to strengthen the assembly. The various components can be sealed with an adhesive as previously described.
The present invention has been described with reference to certain preferred versions thereof; however, other versions are possible. For example, the transportation package 802 and transportation fixture 200 can be used in other types of applications, as would be apparent to one of ordinary skill, for example, to transport other fragile processing components. Other configurations of the transportation fixture 200 can also be used to accommodate the shape and size of a processing component. For example, the shape of the endplates 210 a, 210 b can be shapes other than that triangular or frames, for example, square, hexagonal or even round plates or frames. The shell 800 can be also made from other materials or have a small window of transparent material surrounded by opaque material. The casing 870 can also have other shapes, for example, cylindrical and can be built of steel or other metals. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.

Claims

1. A transportation fixture for holding a substrate rack, the transportation fixture comprising:

(a) top and bottom endplates;

(b) a plurality of posts attaching the top endplate to the bottom endplate, the posts spaced apart a sufficient distance to confine the substrate rack therebetween, each post having a longitudinal inside edge; and

(c) a plurality of compliant bumpers that are each coupled to a longitudinal inside edge of a post.

2. A transportation fixture according to claim 1 wherein the posts are joined to the endplate by a pin that forms a hinge.

3. A fixture according to claim 1 wherein the top and bottom endplates are triangular.

4. A fixture according to claim 3 wherein the triangular endplates have apexes, and wherein the posts are joined to the apexes.

5. A fixture according to claim 3 wherein the triangular endplates have slots at their apexes that are sized to receive the posts.

6. A fixture according to claim 5 wherein a triangular endplate comprises a pair of hinge blocks disposed about one of the slots, the pair of hinge blocks having facing sidewalls that include holes that align with a hole in the post to allow a pin to be passed through the aligned holes to hold the post to the endplate.

7. A fixture according to claim 1 wherein the top and bottom endplates include reinforcing structures.

8. A fixture according to claim 7 wherein the reinforcing structures comprise finger-holds for carrying the fixture.

9. A fixture according to claim 1 wherein each compliant bumper comprises a polymer tube.

10. A fixture according to claim 9 wherein each polymer tube includes a textured surface.

11. A fixture according to claim 1 wherein each post comprises a pair of strips that house a rod.

12. A fixture according to claim 1 wherein the top and bottom endplates, the posts, and the compliant bumpers are made from a non-metallic and heat-resistant material.

13. A transportation package comprising the fixture of claim 1 enclosed in a shell, at least a portion of the shell being light permeable.

14. A transportation package according to claim 13 wherein the shell comprises a pair of opposing trays.

15. A transportation package according to claim 14 wherein the trays each have a closed end and an open end with a circumferential lip, and wherein the trays are joined at their circumferential lips so that their open ends face each other.

16. A transportation package according to claim 13 wherein the shell comprises an exhaust port coupling and a purge gas coupling.

17. A transportation package according to claim 13 further comprising a hard casing having a foam interior to receive the shell.

18. A transportation fixture for holding a substrate rack, the transportation fixture comprising:

(a) top and bottom endplates that are triangular and have apexes;

(b) three posts that attach to the apexes of the top and bottom endplates; and

(c) a compliant bumper coupled to each post.

19. A fixture according to claim 18 wherein the endplates further comprise reinforcing structures having cut-out handles.

20. A fixture according to claim 18 wherein the endplates have slots at their apexes that are sized to receive the posts.

21. A fixture according to claim 18 wherein each endplate comprises a pair of hinge blocks disposed about a slot, the hinge blocks having facing sidewalls that include holes that align with a hole in the post to allow a pin to be passed through the aligned holes to hold the post to the endplate.

22. A transportation package comprising the fixture of claim 18 enclosed in a shell having at least a portion which is light permeable.

23. A transportation package according to claim 22 further comprising a hard casing having a foam interior to receive the shell.

24. A transportation shell comprising:

(a) a first tray having a closed end and an open end with a first circumferential lip, at least a portion of the first tray comprising a light permeable material;

(b) a second tray comprising a closed end and an open end with a second circumferential lip, at least a portion of the second tray comprising a light permeable material, and wherein the second circumferential lip mates with the first circumferential lip such that the open ends of the first and second trays face each other; and

(c) a sealing gasket between the first and second circumferential lips to form a seal therebetween.

25. A shell according to claim 24 wherein first and second trays comprise cylinders.

26. A shell according to claim 24 wherein circumferential lips extend outwardly, and transversely, from the shells.

27. A shell according to claim 24 comprising an exhaust port coupling and a purge gas coupling.

28. A shell according to claim 24 wherein the light permeable material comprises a visible light transmission percentage of at least about 20%.

29. A shell according to claim 24 wherein the light permeable material comprises a heat setting thermoplastic polymer.

30. A shell according to claim 24 wherein the light permeable material comprises polyethylene terephthalate (PET), glycol-modified PET (PETG), oriented PET (O-PET), polyethylene naphthalate (PEN), or blends thereof with each other or with other resins.

31. A shell according to claim 24 wherein the light permeable material comprises polyethylene terephthalate glycol.

32. A transportation package comprising the shell of claim 24 and further comprising a hard casing having a foam interior to receive the shell.

33. A method of manufacturing the shell of claim 24 by molding the first and second trays using thermoforming methods.

34. A method according to claim 33 comprising molding each of the first and second trays as integral pieces from a single sheet of thermoplastic material.

35. A transportation package for transporting a substrate processing substrate rack, the transportation package comprising:

(a) a shell comprising a pair of opposing trays that each have a closed end and an open end with a circumferential lip, the trays being joined at their circumferential lips to define a cavity inside the shell; and

(b) a transportation fixture inside the cavity, the transportation fixture comprising:

(i) top and bottom endplates; and

(ii) a plurality of spaced apart posts attaching the top endplate to the bottom endplate to confine the substrate rack therebetween, each post having a longitudinal inside edge; and

(iii) a plurality of compliant bumpers that are each coupled to a longitudinal inside edges of a post.

36. A transportation package according to claim 35 wherein the top and bottom endplates are triangular and have apexes, and wherein the posts are each joined to an apex of a triangular plate.

37. A transportation package according to claim 35 further comprising a hard casing having a foam interior to receive the shell.

38. A transportation package for transporting a substrate processing substrate rack, the transportation package comprising:

(a) a rigid casing having an interior foam block that is contoured to match the shape of a shell; and

(b) a shell that fits in the contoured interior foam block, the shell comprising:

(i) a first tray having a closed end and an open end with a first circumferential lip, at least a portion of the first tray comprising a light permeable material;

(ii) a second tray comprising a closed end and an open end with a second circumferential lip, at least a portion of the second tray comprising a light permeable material, and wherein the second circumferential lip mates with the first circumferential lip such that the open ends of the first and second trays face each other to define a cavity sized to receive a transportation fixture; and

(iii) a sealing gasket between the first and second circumferential lips to form a seal therebetween

39. A transportation package according to claim 38 wherein first and second trays comprise cylinders.

40. A transportation package according to claim 38 wherein the circumferential lips extend outwardly, and transversely, from the shells.

41. A transportation package according to claim 38 wherein the shell comprises an exhaust port coupling and a purge gas coupling.

42. A transportation package according to claim 38 wherein the light permeable material comprises a visible light transmission percentage of at least about 20%.

43. A transportation package according to claim 38 wherein the light permeable material comprises polyethylene terephthalate glycol.

44. A transportation package according to claim 38 further comprising a hard casing having a foam interior to receive the shell.