CN1071259C - 300 mm microenvironment chamber with side doors - Google Patents

Abstract

The invention discloses a container for forming a microenvironment. The container includes a housing 10, a door 90 and a plurality of uniquely designed supports 60 for securely holding items (such as silicon wafers 80) in parallel with each other and at a distance from each other. The support can be removed. An electrical path is provided to ground the support. Kinematic linkages 44-46 are also provided for placing the container on a surface so that, for example, a door can be properly aligned with the mouth of a wafer processing tool.

Description

300 mm microenvironment chamber with side doors

Background of the invention

Ⅰ Field of Invention

Generally, the present invention relates to packaging of articles. More particularly, the present invention relates to packaging specifically designed to isolate contamination from materials used in the manufacture of electronic semiconductor components and circuits. Such inclusions are particularly suitable for substrates, wafers, memory disks, photomasks, flat panel displays, liquid crystal displays, and the like.

Ⅱ DESCRIPTION OF PRIOR ART

For centuries, people have used various containers to transport items from one place to another. For example, such containers can be used to provide a method of confining items in space for efficient storage. Such containers also provide an easy method of transporting items. Another important function provided by packaging and containers is protection.

The substrates used to make semiconductor circuits, memory hard drives, photomasks, liquid crystal displays and flat panel displays are very sensitive. Effective measures must be taken to protect these items from moisture, particles, static electricity, etc. Measures must also be taken to protect the item from damage caused by vibration and shock within the package. Likewise, measures must be taken to prevent outgassing and particle generation. If the items stored in the packaging are scratched, rubbed or impacted with different surfaces inside the packaging, particles will be generated.

These problems combine to make designing an appropriate package difficult. These issues are only relevant to the environment in which these packages are used.

Proper packaging for storing and shipping wafers, memory disks, photomasks, liquid crystal display panels and flat panel displays is very expensive. Therefore, it is highly desirable that such packaging be reusable and have a durable construction. In addition, such packaging must be able to be cleaned easily and thoroughly. Finally, when packaging is used to manufacture semiconductors, it must be suitable for use with robotic handling and automated manufacturing equipment.

Empak has in the past produced a number of corresponding packages that can be used to handle and ship such items. Some examples of such packages are shown in US Patent 5,273,159 and US Patent 5,423,422. Although, this packaging design has proven to be very effective for smaller items, it is not, for a number of reasons, suitable for storing and transporting items having external dimensions in the range of 300 mm or greater.

Summary of invention

Corresponding containers for wafers, photomasks, memory disks, liquid crystal display panels and flat panel displays must meet several important design criteria. They must be light in weight to facilitate manual and robotic handling. The internal volume of the container should be minimized to reduce storage space requirements and increase storage density. Container height should be minimized to improve container stacking. During transport and storage, the surface area of the polymer surrounding the article should be minimized to reduce inorganic and organic contamination, as well as adverse effects of polymer outgassing.

Containers made in accordance with the present invention meet the design specifications described above. This container also has several other unique advantages. First, by placing the container about the centerline of the item, the accumulation of tolerances is minimized, thereby increasing the positional accuracy of the item stored in such a container. This enhances the effectiveness of inserting and removing items from containers using robotic equipment. Second, the container reduces the risk of damage from static electricity. In a preferred embodiment, this is achieved by providing a conductive path to ground from the static dissipative inner object support to the outer kinematic connection plate of the container. The kinematically linked tablet is used to place containers on different devices. Third, the container of the present invention is designed to be wet cleaned with or without disassembly. Fourth, since the containers of the present invention can be of a unitary design without the need for a separate carrier, the containers can remain associated with a particular batch of items. This allows factory workers to better keep track of a batch of items, thereby reducing the chance of handling errors. Fifth, since no separate boxes are required, the overall design greatly reduces the number of packaged parts required for inventory and the space these parts occupy. Sixth, the overall design does not require precisely placing the removable box in the container and locking it tightly. Finally, the overall design can be manufactured with fewer and smaller parts, thus reducing manufacturing costs.

Accordingly, it is an object of the present invention to provide an insulated container which protects the contents of the container from contamination by particles or moisture.

Another object of the present invention is to provide a container that protects the items stored therein from damage due to shock and vibration, and from damage caused by the items scratching, rubbing or impacting the various surfaces of the container .

Yet another object of the invention is to provide a container that is reusable and easy to clean.

Yet another object of the present invention is to provide such a container whose internal structure is less prone to wear or generation of particles which tend to contaminate the packaged contents.

Yet another object of the present invention is to provide such a container which is very efficient when used with automatic handling or handling equipment.

Yet another object of the present invention is to provide a structure that is easily handled, manipulated and transported by persons.

These and other objects are achieved by providing a container having a housing with openings for inserting and removing items; a door capable of effectively sealing the opening; a plurality of items within the housing held structures that securely hold items and keep items at a distance from each other; a kinematic joint plate that helps align the container with the mouth of the equipment used to handle items in the factory; and ergonomics Schematically designed handles that can be effectively used for manual or manipulation by robotic means. In order to reduce the contamination caused by particles inside the container, the object support is made of high temperature resistant conductive material. Special supports are also grounded to the exterior of the container (described in detail below). The entire container is constructed to provide maximum support and protection for the articles, ease of handling and, to the extent possible, minimize the height and weight of the container.

The present invention can be better understood through the following description of preferred embodiments in conjunction with the accompanying drawings. Although the description and drawings are specific to microenvironmental chambers for silicon wafers, the invention described is applicable to other applications as well. For example, the storage and transportation of photomasks, memory hard disks, liquid crystal display panels, flat panel displays, etc.

Brief description of the drawings

Figure 1 is a perspective view of a container shell made in accordance with the present invention;

Fig. 2 is the top view of container housing;

Fig. 3 is the cross-section of the container taken through the line A-A of Fig. 2;

Fig. 4 is the container cross-section taken by the B-B line of Fig. 2;

Figure 5 is a side view of a container incorporating the present invention;

Fig. 6 is the cross section of the container through the C-C line of Fig. 5;

Figure 7 is a view of the container seen from the side opposite the door;

Fig. 8 is the figure of kinematic connection plate;

Fig. 9 is the cross-section of the connecting plate through the movement of the D-D line of Fig. 8;

Fig. 10 is the cross-section of the moving connection plate through the E-E line of Fig. 8;

Fig. 11 is the cross-section of the connection plate through the motion of the F-F line of Fig. 8;

Figure 12 is a perspective view of one of the ergonomic handles used in the design;

Figure 13 is an end view of the handle;

Fig. 14 is the cross-section of the handle passing through the G-G line of Fig. 13;

Figure 15 is a plan view of the door of the container in a closed position relative to the container housing;

Figure 16 is a perspective view of a cushion that may be secured to the interior surface of the door to assist in supporting and maintaining items stored in the container in place during storage and transport; and

Figure 17 is a cross-section showing two opposing spacers and wafers.

Description of the preferred embodiment

As shown in FIG. 1, the container of the present invention has an outer shell 10 . Housing 10 has six sides 12 , 14 , 16 , 18 , 20 and 22 .

The side 12 comprises a door frame 6 which in turn has two opposite end portions 7 and two side portions 8 . The sides 14 and 16 of the housing 10 are generally formed by straight walls extending from the opposite end portion 7 of the door frame 6 . A wall 18 extends between walls 14 and 16 and is part-cylindrical in shape. The radius of curvature of the wall 18 is generally the same as that of the wafers stored in the container. Together, the top surface 20 and the bottom surface 22 form a complete container. Walls 20 and 22 generally have a flat surface 24 and stiffeners 26 projecting outwardly from the flat surface 24 . The reinforcement 26 prevents warping of the container, particularly the walls 20 and 22. The stiffener 26 has four legs 28 , 30 , 32 and 34 . Between the two legs 30 , transverse supports 31 protrude across the wall 18 . Likewise, a lateral support 33 extends between the two legs 32 . The lateral supports 31 and 33 can be used to support the housing 10 on a flat surface if the container is placed with the wall 18 facing down.

Also shown in FIG. 1 is a kinematic linkage plate 40 . Figures 1-5 and Figures 8-11 show the structure of the kinematic linkage plate in more detail. The panel is secured to the wall 20 by a number of mounting struts 42 (see FIG. 5). Three separate connection slots 44, 45 and 46 are formed in the kinematic connection plate 40. These slots are designed to mate with posts on the processing equipment (not shown) so that the access openings 8 are aligned with the ports on the processing equipment. As best shown in FIG. 10, the slots 44, 45 and 46 are Y-shaped including a narrower, deeper central through hole 47 and a wider, less deep upper channel 48. The upper channel 48 is intended to cooperate with the alignment post of the processing equipment and guide it into the central channel 47 for proper alignment. Proper alignment is achieved when three alignment posts on the handling device (not shown) cooperate with the central channel 47 of the slots 44, 45 and 46.

The kinematic connection plate 40 is made of conductive material. The plate is designed to include two screw mounts 49 . As will be explained below, each member 49 may accommodate a screw for electrically connecting the kinematic connection plate 40 to a wafer support 60 disposed within the container. This electrical connection forms a path through which the wafer support can be grounded, dissipating the charge on the wafer or wafer support, thereby preventing damage to the wafer due to static electricity.

FIG. 1 also shows a pair of handles 50 . These handles are placed at the center of gravity of the container. The handle is designed according to the principle of ergonomics, so that the human hand can easily hold the handle from different angles. The design of the handle 50 also allows the handle to be efficiently held by robotic handling equipment.

More specifically, each handle includes a support post 51 which connects the handle 50 to the housing 10 together, and also includes a pair of wider grip members 52 . The shape of the grip 52 is such that it can be comfortably grasped by a human hand. At the end of the grip member 52 there is a recessed groove. Slot 53 is generally straight and includes a notch 54 . Slot 53 and notch 54 are provided to allow the gripping member of the robot arm to engage therewith. In this way, the container is designed so that it can be easily, efficiently and safely handled by humans or robots.

3, 4 and 6 show some internal structures of the housing 10 which are not visible in FIG. For example, FIGS. 3 and 4 show wafer supports 60 and 62 which cooperate to hold up to thirteen wafers 80 . Typically, 12 wafers 80 are finished wafers and one wafer is a trial wafer. Both wafer supports 60 and 62 are made of a high temperature resistant conductive material. As shown, each wafer support 60 and 62 has fourteen wafer spacers 65 . Between each pair of spacers 65, a wafer edge receiving groove 66 is formed. The grooves on the wafer support 60 cooperate with the grooves on the wafer support 62 to hold the wafer 80 parallel to each other and at a certain distance from each other, as shown in FIGS. 3 and 4 . Those skilled in the art will appreciate that wafer supports 60 and 62 can be modified to hold more (eg 25) wafers, or fewer wafers (eg 7) without departing from the invention. Likewise, wafer supports 60 and 62 may be sized to support something other than wafers, or to support wafers of different sizes.

In the preferred embodiment shown, each slot 66 is specifically configured to support a 300mm wafer. The base side of each groove is curved in both the circumferential direction (eg, the circumferential direction of wafer 80 ) and the lateral direction (eg, across the thickness of wafer 80 ). The curvature of the base side of each groove 66 in the circumferential and transverse directions is approximately the same as the radius of curvature of the outer edge of the wafer 80 which is 300 mm. The same radius of curvature along the circumference allows the base side of the groove to contact the edge of the wafer 80 along a circular arc, rather than just at one point.

There are a number of distinct advantages to shaping the wafer spacer 65 as shown in FIG. 17 . The wafer spacer has a continuously varying slope so that gravity assists in centering the wafer 80 in the middle of its carrier. When using this type of wafer spacer 65, the wafer always rests on the portion of the wafer spacer with a defined slope, whereby edge contact is ensured. Also, if for any reason, one edge of the wafer goes up much faster than the other goes down when the wafer is being removed from the dead center. Thus, for carriers where the wafers are transported horizontally, gravity can be used to help center the wafers on the support. Once centered, the vertical position of the wafer is precisely determined. As the carrier moves from one position to the next, small vibrations may help center the wafer in the carrier, thereby improving the horizontal and vertical positional accuracy of the wafer.

A side benefit of the wafer support design shown in Figure 17 is that, for a given support strength, the lowest possible large cross-section can be obtained. Spacer 65 is an impeded area for movement of wafer 80 as the wafer is inserted into and removed from the carrier. A thin spacer is better because there is less chance of the wafer 80 hitting the spacer and generating particles. On the other hand, the spacer 65 must be of sufficient thickness in order to support the wafer 80 and avoid deflection by the wafer during the life of the container. In view of these contradictory requirements, the partitions are designed to have continuously changing angles, as shown in Figure 17.

In the preferred embodiment, two screws 64 are provided. One of the screws 64 is used to form a conductive path between the wafer support 60 and the conductive kinematic connection plate 40 . Another screw 64 is used to form a conductive path between the wafer support 62 and the kinematic connection plate 40 . An advantage of this configuration is that the wafer supports 60 and 62 can be grounded via the screw 64 and the kinematic connection plate 40, so that the wafer supports 60 and 62 are not charged. The wall of the casing 10 is not grounded and has a small amount of negative charge, which will cause the particles in the container to migrate and attach to the wall of the container. These particles will not cause damage to the wafer. Since the screw 64 does not ground the housing 10, it is desirable to line the hole in the housing 10 through which the screw 64 passes with a layer of insulating material.

In order to close the access opening 8 of the housing 10, a door 90 is provided. The door 90 is shaped and sized to fit within the door frame 6 . When in place, the door engages the door frame 6, sealing the container. Likewise, the outer edge of the door frame 6 may also be used to form a seal around the access opening 8 between the door frame 6 and the mouth of the tool for processing the semiconductor wafer 80 . If such a seal is formed before the door 90 is opened, the risk of contamination is reduced. When this seal is formed, door 90 can be safely opened so that wafer 80 can be removed from housing 10 through the opening and placed into a processing tool without too much risk of contamination. Typically, a number of latches (not shown) are provided to hold the door in the closed position. In addition, in order to ensure that the door 90 and the door frame 6 are completely sealed, a flexible gasket or sealing ring is placed between the door 90 and the door frame 6 .

The door 90 may be provided with a wafer cushion 92 . As shown in Figure 16, the cushion 92 has two rigid rails 93 and 94 and a plurality of deformable transverse members 95. Thirteen deformable transverse members 95 are shown in FIG. 16 . Each cross member has two partitions 96 . Each spacer 96 is in line with spacer 97 on rigid rail 93 and with spacer 98 on rigid track 94 . Thus, when the door 90 is closed, the wafer 80 forms a snap groove engagement with the partitions 96, 97 and 98. Cross member 95 will deform until the edge of wafer 80 also engages rigid rails 93 and 94 . Even if the wafer 80 is subjected to sudden vibrations during transportation, thanks to the deformable cross member 95, the contact of the cushion pad 92 with the support is not lost.

The inclusion of such a wafer cushion 92 on the door 90 provides three support areas for the wafer 80, thereby reducing movement and vibration of the wafer 80 during transport. Supporting the wafer 80 in three regions reduces damage to the wafer due to scratching, rubbing, or impact on the interior surfaces of the container, and also limits the generation of particles caused by such scratching, rubbing, or impact. Finally, a device for kinematic connection of the door 90 to another surface can also be provided outside the door. This may be a series of three slots (not shown) of the kind shown in the kinematic linkage plate 40 that cooperate with protrusions on the surface, or three protrusions on the door 90 that cooperate with grooves on the surface. part.

Although the invention has been described and shown in terms of the most preferred embodiment, the invention can also be used for the transportation and storage of liquid crystal displays, flat panel displays, photomasks, memory hard disks, substrates, and the like. Additionally, the various components of the present invention can be made removable and replaceable to extend the useful life of the container. This is also true for wafer supports 60 and 62 and wafer cushion 92, which can be removed and replaced with supports or cushions more suitable for other items to be contained in the container. Therefore, it should be understood that the description and illustrations herein are not restrictive.

Claims (13)

1. A container for a microenvironment capable of protecting items stored therein from damage, the container comprising: (a) a housing having openings for inserting and removing articles from said housing, said housing being made of a material that inherently carries a small negative charge; (b) two supports cooperating to support a plurality of articles stored in the container in parallel and spaced positions relative to each other; (c) a door for sealing said opening of said housing from contamination of items stored in said housing; and (d) A means for forming an electrical path through which said support is grounded so that particles inside the housing are drawn away from said article and support and towards the housing of said container. 2. 3. The container of claim 1 wherein said items stored in the container are semiconductor wafers. 3. The container of claim 1, further comprising two handles located on opposite sides of the center of gravity of the container. 4. 3. The container of claim 3, wherein each of said handles has a slot including an alignment notch so that the handle can be easily and securely gripped by a robot. 5. The container according to claim 1, further comprising a kinematic connection plate fixed on the outside of the housing with a plurality of pillars, said kinematic connection plate has three alignment slots, each of said alignment slots is horizontal The cross section is generally Y-shaped. 6. The container of claim 5, wherein said alignment slot of said kinematically coupled plate is used to align the door of the container with the mouth of a tool for processing semiconductor wafers such that when the container door is opened, the A seal is formed around the opening of the housing and the port of the tool before the wafer is removed from the housing through the port and inserted into the tool for processing. 7. The container of claim 1, further comprising a kinematic joint plate fixed to the exterior of the housing, said kinematic joint plate being made of a conductive material. 8. 7. The container of claim 7 wherein said means for forming an electrical path through which the supports are grounded includes an electrically conductive connection between each of said supports and said kinematic connection plate. 9. 2. The container of claim 1, wherein said door includes a means on an outer surface thereof for connecting said door to another surface. 10. 3. The container of claim 1, wherein each of said supports is releasably secured to the housing so that such supports can be removed for cleaning or replacement. 11. 2. The container of claim 2, wherein said support has a plurality of grooves, the base side of each of said grooves being curved in the circumferential direction. 12. The container according to claim 11, wherein the radius of curvature of the base side of said groove in the circumferential direction is generally the same as the radius of curvature of said wafer in the circumferential direction. 13. The container of claim 2 wherein each of said two supports includes a plurality of wafer spacers, each of said wafer spacers having a continuously varying slope to assist in supporting said semiconductor wafers of a wafer.

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