KR100418107B1 - Container with vacuum-actuated mechanical latch and graffiti - Google Patents

Abstract

A vacuum actuated mechanical latch 34 that can be attached to an airtight sealable container 10 is described. The latch 34 is attached, formed or otherwise coupled to the door 12 of the container 10. The latch 34 is easily engaged and separated by the processing device 14. In addition, the latch 34 is designed to minimize the amount of worn dust, and further isolates any dust generated. In addition, when the door 12 is latched to the container 10, the latch 34 is not easily overpowered by colliding or vibrating. Guide surface 88 of latch 34 is angled to minimize friction when latch 34 is forced toward the first locking position.

Description

Vacuum-actuated mechanical latches and containers with them

Sensitivity to contamination of materials used in semiconductor manufacturing is of great importance to semiconductor manufacturers. Standardized mechanical interface systems (SMIF) have been designed to reduce contamination from airborne dust or vapors during the processing, transportation and storage of sensitive materials. The SMIF system includes an airtight sealable container used to transport semiconductor substrates made of sensitive materials. SMIF cassettes are commonly used to receive semiconductor substrates in SMIF containers. The semiconductor substrate may include a wafer, LCD, flat panel display, or may include a memory disk. For the sake of explanation, a semiconductor wafer is intended, which is not intended to limit the present application to a semiconductor wafer.

In the processing, transportation and storage of semiconductor wafers, it is important that the semiconductor wafers are isolated from harmful dust. The size of the dust that damages the semiconductor wafer is determined by the geometry of the semiconductor. As the geometry of the semiconductor becomes smaller, the amount of dust to be removed also decreases. The presence of vapor or static electricity in the ambient atmosphere also damages semiconductor fabrication, including the wafer itself. Thus, the use of materials with low outgassing properties is required.

It has been found that minute wear of SMIF systems containing semiconductor wafers can generate hazardous dust. Static electricity attracts worn hazardous dust into SMIF containers or the semiconductor wafer itself. If the dust is sucked into the inner surface of the SMIF container, the dust may be air dispersed when moving the container and damages the semiconductor wafer after sinking on the semiconductor wafer. Circulation and filtration of air or other gases in the SMIF container does not easily remove dust from the inside of the SMIF container. Even if the SMIF container is cleaned, it is difficult to completely remove dust attracted to the inner surface of the container from the container.

Maintaining a suitable clean environment during the transport, processing and storage of semiconductor wafers is important. Automatic processing equipment has been modified to minimize the contact and exposure of semiconductor wafers with hazardous dust. In addition, the container or isolation structure has been modified to protect the wafer and to be Robert-operated by processing equipment. Typically, the isolation or SMIF container is hermetically sealed to the outside environment by a door or lid and only opened when used in a minimal, clean environment by the port door of the processing tool. In this way, the risk of contamination is substantially reduced. Therefore, it is important that the door of the SMIF container is hermetically sealed if it is not separated by the processing equipment in a clean environment.

Once the airtight seal is formed, the door must remain fixed in the container. Various latching arrangements have been developed for various latching assemblies that secure doors to containers while minimizing mechanical momentum and dust generation. Such a device is disclosed in US Pat. No. 5,291,923 ('923 patent) to Gallagher et al. This patent discloses flexible collapsible membranes or bladder type seals. Vacuum is applied through the manifold to the inside of the contact member used to seal the SMIF container. When a vacuum is applied, it is possible to break the seal and thus detach the door. When the vacuum is released, the seal slowly expands to its original form. In order to reduce the time it takes for the seal to expand to its original form and seal the door to the container, a positive may be applied.

The assembly disclosed by Galper et al. Has been found to be effective in a variety of environments. However, severe collisions or vibrations may cause the door to be detached from the container and contaminate the semiconductor wafers stored in the container. In a typical manufacturing facility, such collisions and vibrations occur very often. In addition, the vacuum assembly increases the time required for the processing equipment to separate or engage the door to the container. Thus, there is a need for a latching member that can be quickly joined or separated and that is not easily separated by collision or vibration.

Various latches have been used some successfully, as disclosed in US Pat. No. 4,724,874 to Parih et al. However, efforts to design latches that do not generate dust when the latches engage and disengage have been unsuccessful. As described above, the generated dust can damage the semiconductor wafer even if the amount is small.

Therefore, above all, (1) it must be able to be effectively combined and separated by the processing equipment, (2) must withstand the shock or vibration of the container, (3) minimize the generation of contaminant dust during latch operation, ( 4) A latch is needed to isolate and remove worn dust from the latch so that the dust does not contaminate the contents of the container. An object of the present invention is to provide such a latch.

Summary of the Invention

The present invention provides a vacuum actuated mechanical latch that can be used to secure a door to the opening of a container. The latch is designed to minimize dust generation during operation. The latch is also designed to isolate and remove dust generated by the latch, so that the dust does not contaminate the interior or surrounding environment of the container. Vacuum operated mechanical latches can be used on all types of hermetically sealed containers, but are described with reference to SMIF containers for explanation. Those skilled in the art will appreciate that the vacuum actuated mechanical latch can be modified for use on containers of other shapes or sizes.

In a preferred embodiment, the vacuum actuated mechanical latch includes a housing, a plunger and a compression spring. Since the housing has a mortise provided therein, the plunger can slide between the first locking position and the second retracted position (opening position) in the mortis. The mortis extends from the outer surface of the housing, forming an opening in the housing. The mortis ends in the housing and forms the closed end of the mortis. When the plunger is in the first locking position, a portion of the plunger extends out of the housing through the opening of the housing. The compression spring serves to bias the plunger through the mortis toward the first locking position. The duct extends towards the mortise, whereby a vacuum is applied to overcome the spring force, thereby actuating the plunger from the first locking position to the second retracted position (open position).

The latch is attached to the underside of the door hermetically sealed to the container. The container has four sealed sides, a sealed top and an open bottom. The open floor is surrounded by a lip. A recess is formed on the lip inner surface of the container. When the plunger is in the first locking position, each recess engages with the plunger of the corresponding latch, thereby securing the door to the container. Of course, the latch can be integrally formed in the container and can be latched in the recess formed in the door. In a preferred embodiment, the respective latches engage with each inner surface of the container. One skilled in the art will appreciate that if the container or pod is, for example, cylindrical, three latches spaced at equal intervals are sufficient to seal secure the door to the container.

When the door is secured to the container, vacuum is applied to the latch to retract the latch from the recess. When the latch is retracted by vacuum, the dust in the latch is extracted from the latch by the vacuum, so that the dust does not contaminate the inside or outside environment of the container. If the vacuum is reduced such that the spring biases the plunger toward the locked position, a slight vacuum may be applied to generate a back pressure that removes dust that occurs when the plunger slides through the mortis.

Vacuum is applied through a duct extending towards the mortis near the closed end of the mortis. A vacuum is applied through the duct to sufficiently overcome the compression spring force, pulling the plunger and head towards the mortis. When the plunger head protrudes from the housing, the plunger is in the first locking position and when the plunger head retracts toward the mortis, the plunger is in the second retracted position (open position). The force exerted by the compression spring should be able to sufficiently hold the plunger in the locked position, even if the container collides or vibrates.

In a preferred embodiment, the plunger and mortis have a clearly matched shape. The plunger is composed of a barrel having a head formed at one end and a seating portion formed at the other end. The compression spring is located between the seat of the plunger and the closed end of the mortis. The barrel includes a shoulder extending from the other end toward the head and inclined from the first large diameter portion to the first small diameter portion. This ramp serves as a stop to ensure that the plunger does not slip completely from the housing.

The plunger may have a recess extending toward the plunger along the longitudinal axis of the barrel portion. A portion of the compression spring may be located in the recess. In addition, an annular channel may be formed in the plane of the seat. Gaskets or zero rings may be located in the channel formed in the seat. When the plunger is pulled into the second open position by vacuum, the 0-ring sealably contacts the closed end of the mortis.

When the plunger is sealed against the closed end of the mortis, the vacuum pressure changes. This change in pressure can be used as an indicator that the latch has been retracted to the second open position relative to the processing facility. Before the plunger seals against the closed end of the mortis, the particulates generated by the latches are sucked by the vacuum and further isolate the semiconductor wafer from any harmful dust.

In another preferred embodiment, the latch is formed in the door itself. The door functions as a housing for all four latches. Each side of the door is provided with a mortise so that the plunger can slide in the mortise between the first locking position and the second retracted position (open position). Ducts extend into each mortis from the bottom of the door. In this configuration, the port door of the processing apparatus can seal around the outer periphery of the door, thereby forming a manifold that connects all of the ducts of the plurality of latches to the central vacuum line.

In another preferred embodiment, the latch includes a flexible elastomeric seal attached to the head of the plunger. The seal creates a vacuum chamber in the mortis cavity and further isolates the plunger and spring from the outside environment.

Such a vacuum actuated mechanical latch provides three or more advantages, which do not limit the present application. First, the door and the container are firmly fixed together. Second, when the latch is actuated, a cushion of air is present between the motis and the plunger to float the plunger into the mortis, thereby reducing the scraping between the motis and plunger when the plunger slides in the mortis. Third, the vacuum functions to draw any dust that may be generated from the latch. Thus, the design offers several unique advantages.

It is therefore an object of the present invention to provide a vacuum actuated mechanical latch that secures a door to a container.

It is still another object of the present invention to provide a latch for an SMIF container which is not damaged by a collision force or a vibration force.

It is another object of the present invention to provide a mechanical latch that minimizes and isolates the amount of dust generated by the latch.

Still another object of the present invention is to provide a latch which can be easily released while being easily coupled by an automatic treatment facility.

It is a further object of the present invention to provide a latching system comprising means for instructing the processing facility that the latch is in the open position.

It is still another object of the present invention to provide a latching system that seals most of the moving mechanism included in the latches from the external environment.

It is yet another object of the present invention to provide a latching system that can reduce the degree of external vacuum required to operate the latch.

These and other objects, and these and other features and advantages of the present invention will become apparent to those skilled in the art upon examination of the following detailed description of the preferred embodiments in conjunction with the accompanying drawings and claims.

The present invention generally relates to a mechanical latch used to secure a door or lid to a container. More specifically, the present invention relates to a vacuum actuated mechanical latch that latches a door in a container to hold the door in a hermetically sealed position. When the container is collided or vibrated, the latch does not leave or detach from the container.

1 is an exploded perspective view showing a door and a container in which a part of a processing device is lifted up;

2 is a perspective view showing the latch removed from the door.

3 is a plan view showing the bottom stop of the latch housing of the type shown in FIG. 2 with the plunger in the first locking position.

4 is a bottom view showing the upper stop of the latch housing of the type shown in FIG.

FIG. 5 is a plan view showing the bottom stop of the latch housing of the type shown in FIG. 2 with the plunger in the second retracted position (open position); FIG.

FIG. 6 is a perspective view illustrating the plunger of the type shown in FIG. 3. FIG.

FIG. 7 is a plan view of the plunger of the type shown in FIG. 3 with the compression spring removed. FIG.

8 is a plan view showing a raised door and a preferred optional plunger in accordance with a preferred embodiment of the processing apparatus.

9 is a plan view showing a preferred example of the bottom stop of the latch housing with the plunger in the first locking position.

10 is a plan view showing another preferred alternative of the bottom stop of the latch housing with the plunger in the first locking position.

First, referring to FIG. 1, a container 12 and a door 12 mounted above a port door of a semiconductor wafer processing tool 14 is shown. The container 10 has a sealing top 16 and a side wall 18. The lip 20 extends along the perimeter to form the open end 22 of the container 10. The sealing surface 24 is formed on the interior 26 of the lip 20. In a preferred embodiment, the latching recesses 28 are formed in the interior 26 of the lip 20 below the sealing surface 24 on each inside of the container 10.

The door 12 is planar and sized to seal against the sealing face 24 of the container 10. The compressible seal 30 (not shown) is aligned with the upper surface periphery 32 of the door 12 that engages the sealing surface 24 of the lip 20. A compression force of about 5 pounds is required to hermetically seal the door 12 to the container 10.

The latch 34 is attached to the door 12 by conventional means and arranged to correspond with the latch recess 28. When the door 12 is sealably coupled to the container 10, each of the latches 34 engages the recess 28 of the corresponding container 10 with a compressive force of less than about 5 pounds, so that the door 12 To prevent deviations. The engaged latch 34 also prevents the door 12 from moving or vibrating from the sealingly engaged state with the container 10. Even if the container is mishandled or upside down, the latch prevents the door 12 from leaving the container 10.

The various devices used in the semiconductor manufacturing process must have the property of reducing ambient dust, vapor or static charge. The container 10 is preferably formed by combining a polycarbon salt with polytetrafluoroethylene (PTFE) having a volume of about 10-30%, but is not limited thereto. In addition, the door 12 is preferably made of a polycarbon salt, and the latch 34 is preferably made of a material having a low gas discharge, a low coefficient of friction, and a high insulating coefficient. One such material is E, I. dupont de Nemours & Co. DELRIN ™ is commercially available from (Inc.).

Next, latch 34 is schematically shown in FIG. 2. In view, the latch 34 includes a housing 36, a plunger 38 and a compression spring 40. As shown in FIGS. 3-7, the shape of the plunger 38 indicates that the housing 36 consists of upper and lower members 42 and 44. Those skilled in the art will appreciate that the shape of the plunger can be changed so that the housing can be composed of one single member. The upper and lower members 42 and 44 can be fastened via a bore 46 with its own tapping screw or can be joined together by other known means. The specific elements of latch 34 will now be described in more detail.

3 and 4, the upper and lower housing members 42 and 44 are shown in more detail. The upper housing 42 has an upper mortise 50 formed therein, and a lower mortise 52 is formed inside the lower housing. When the upper and lower housing members 42 and 44 are aligned and engaged, the upper and lower mortises 50 and 52 are aligned with each other to form the mortis 48 of the housing 36. The upper and lower mortiss 51 and 52 are identical.

In general, the mortise 48 partially extends towards the housing 36 up to the sealing end 54 of the mortise. The open end 56 of the mortis is formed on the outer end 58 of the housing 36. In the preferred embodiment shown in FIGS. 3 to 7, the mortise 48 has the overall shape of the plunger 38. The mortis 48 has a first cylindrical portion 60 and an inclined portion 62 inclined from the first cylindrical portion 60 to a smaller second cylindrical portion 64. The second cylindrical portion 64 extends up to the cavity 66 which opens to the outer end surface 58 of the housing 36 (see FIG. 4). The vacuum duct 68 extends from the bottom surface 70 of the bottom housing 44 toward the sealing end 54 of the mortise 48.

6 and 7 show a plunger 38 schematically. In use, the plunger 38 is installed in the mortise 48 for sliding between a first closed locking position (shown in FIG. 3) and a second open position (shown in FIG. 5). The plunger 38 has a barrel or body 76 having a head 78 formed at one end and a seating portion 80 formed at the other end. The inclined shoulder 82 inclines along the longitudinal axis of the cylinder 76 from the large diameter portion 84 starting from the seating portion 80 of the plunger 38 to the second small diameter portion 86. The head 78 of the plunger 38 has an inclined guide surface 88 which minimizes friction when the plunger is pressed into the recess 28 of the container 10.

The seating portion 80 of the plunger 38 has a recess 90 that extends toward the cylinder 76 along the longitudinal axis of the cylinder 76. A compression spring 40 is inserted into the recess 90 to allow the use of longer compression springs. As shown in FIGS. 3 and 5, the compression spring 40 is located between the closed end 54 of the mortise 48 and the plunger 38. The compression spring 40 is sized to bias the plunger 38 toward the first locking position.

In a preferred embodiment, the annular channel 92 is formed along the periphery of the plane of the seating portion 80. The replaceable gasket or zero ring 94 may be coupled in the channel 92 of the seat 80. The diameter of the vacuum duct 68 is smaller than the outer diameter of the seating portion 80 and the inner diameter of the 0-ring 94. When the plunger 38 retracts to the second open position, the 0-ring 94 seals against the closed end 54 of the mortise 48. Those skilled in the art will appreciate that the vacuum duct 68 may extend from the outer surface of the housing 36 to other portions of the mortise 48. However, extending the duct 68 toward the closed end 54 of the mortise 48 minimizes the amount of vacuum required to retract the plunger 38 to the second open position.

The shoulder 82 of the plunger 38 and the inclined portion 62 of the mortise 48 have the shoulder 82 when the compression spring 40 presses the plunger 38 to the locked position. By having a size to function as a stop with respect to the inclined portion 62, the moving distance of the plunger 38 is limited (see FIGS. 3 and 5).

The head 78 of the plunger 38 has a size slightly smaller than the open end 56 of the mortise 48. The lip 96 is formed on the head 78 of the plunger. When the head 78 of the plunger is pressed through the opening 56 of the housing 36, the lip 96 is in contact with the inner peripheral surface 98 (see FIG. 4) of the open end 56 of the mortise 48. The open end 56 is sealed. When the lip 96 of the head 78 is in the closed position, dust generated from the sliding motion of the plunger 38 is also trapped in the mortis 48. When a vacuum is applied to release the latch 34 from the container 10, the vacuum sucks in and carries the dust contained in the mortis 48.

Those skilled in the art will immediately understand that the biasing force of the spring 40 must be overcome to move the plunger 38 to the retracted position (open position). In the present invention, a vacuum is applied through the vacuum duct 68 to overcome the spring 40. Using a vacuum to move the plunger 38 also provides the advantage of creating an air cushion between the plunger 38 and the mortise 48 to reduce scraping. This vacuum also functions to suck the vacuum through any dust that may form in the latch 34. When the plunger 38 is deflected from the retracted position (open position) to the locked position, it is sufficient to generate an air cue and to suck in the dust out of the duct 68 through the latch 34, but the deflection force of the spring 40 is reduced. Not enough vacuum is applied to overcome.

Referring next to FIG. 8, a preferred alternative is shown in which the door 12 has a latch 34 formed in the door 12 itself. The door 12 functions as a housing 36 for all four latches 34. The mortise 48 is provided on each end of the door 12 so that the plunger 38 slides between the first locking position and the second retracted position (open position) in the mortis 48. Each vacuum duct 68 extends from the bottom surface 100 of the door 12 toward the closed end 54 of each mortise 48. A replaceable seal 102 of conventional construction is located around the port door 104 of the processing apparatus 14. In this embodiment, the port door 104 of the processing apparatus 14 seals the outer bottom surface 100 of the door 12 and closes all of the vacuum ducts 68 of the plurality of latches 34 to the centerline 108. A manifold is formed to connect to the central vacuum vessel 106 through the.

Referring now to FIG. 9, another preferred bottom half of the latch is shown. Near the closed end 54 of the mortise 48, a vacuum cavity 112 is formed in the mortise. The cavity has an opening 114 in which the plunger barrel 76 slides. One end of the replaceable bellows 116 is attached to the groove 118 in the mortise 48 on the outside of the vacuum cavity 112. The other end of the bellows 116 is attached to the head 78 of the plunger 38, thereby sealing most of the plunger 38 from the external environment. Atmospheric pressure will keep the bellows 116 pushed inward until vacuum is applied. The bellows 116 is preferably made of a flexible elastomeric polymer so that the bellows fold as the plunger 38 moves between the first locking position and the second retracted position (open position). Bellows also improve the suction capacity of the processing unit vacuum.

10 illustrates another preferred alternative of the latch 34. In this embodiment, a single folding bellow attaches most of the plunger 38 to the environment by attaching one end to the housing 36 and the other end to the head 78 of the plunger 38 using conventional means. Seal from. The cavity 66 of the mortise 48 functions as the vacuum cavity 112. Those skilled in the art will appreciate that the flexible elasticity of the bellows eliminates the need for the compression spring 40, thereby pressing the plunger into the first locking position when the amount of vacuum applied is reduced. Thus, those skilled in the art will appreciate that either the bellows 116 or the spring 40 can act as a means for forcing the plunger to the first locking position, where the spring and the bellows can retract to the second open position. The present invention is not limited thereto. In addition, since the plunger 38 is sealed in the housing 36 by the bellows 116, the 0-ring 94 may not be necessary. The conventional retainer ring 120 is used to receive the bellows 116 relative to the outer end surface 58 of the housing 36.

As the structural features of the present invention have been described, the mode of use will now be described. In the preferred embodiment shown in FIG. 1, the user centers the door 12 over the port door 104 of the processing device 14, so that each latch 34 has a suction portion () of the processing device 14. 110). In a preferred embodiment, a negative vacuum is applied through each suction 110 to direct the plunger 38 from the first locking position to the second opening position. Those skilled in the art will appreciate that the vacuum vessel 106 is needed to minimize the time required to generate sufficient suction to pull the plunger 38 to the second open position. This container can also be used as an indicator that the latch 34 is in the open position. When a vacuum is applied to the latch 34, the plunger 38 is sucked toward the second open position. Once the 0-ring 94 is sealed against the closed end 54 of the mortise, the pressure in the container 106 will change, indicating that the latch 34 has fully retracted. The pressure gauge can be connected in communication with the processing apparatus 14, where once the pressure change reaches a predetermined threshold, the processor or user can assume that the latch 34 is in the second open position.

When the processing equipment or the user realizes that the latch 34 is in the open position (by monitoring the pressure in the vacuum vessel), the cassette containing the semiconductor wafer is placed on top of the door 12, and then the container 10 ) Down the door (12). A force is applied to the door 12 to pressurize the seal 30 and to hermetically seal the container and the door. The spring 40 releases the vacuum enough to deflect the plunger 38. The compression spring 40 presses the plunger 38 through the open end 56 of the mortise 48 to the first locked position. After that, the compressive force on the container 10 will be released. The container is in a latched state and is hermetically sealed to the door.

To disengage the door 12 from the container 10, the user aligns the suction part 110 with each latch 34, applying a negative vacuum to the latch 34. The vacuum directs the plunger 38 to the retracted second open position. The door 12 can thus be separated from the container 10.

Herein, the present invention has been described in more detail in order to provide those skilled in the art with information necessary to provide new principles in accordance with patent law, and to make use of such specific components as necessary. However, it is to be understood that the present invention may be carried out in particular on various devices, and that, in addition to the device details and operating procedures, various corrections may be made without departing from the scope of the invention itself.

Claims (16)

A vacuum operated mechanical latch used to secure a door to a container in a sealable combination, a. A housing comprising: a housing having a mortis extending through a portion thereof to the closed end and a bore extending from the outer surface of the housing to the mortis; b. A plunger slidably engaged with the mortis of the housing between a first locking position and a second opening position; c. And pressurizing means for the plunger to the first locking position and retracting to the second open position when a vacuum is applied to the bore, the pressurizing means being coupled to the housing and the plunger. The vacuum operated mechanical latch of claim 1 further comprising plunger operating means for operating said plunger from said first locking position to said second opening position. The vacuum operated mechanical latch of claim 1, wherein the plunger further comprises a barrel having a head formed at one end and a seating portion formed at the other end opposite the head. 4. The mechanical latch of claim 3, wherein the barrel further comprises a shoulder extending from the seat to the head and inclined longitudinally. 4. The vacuum operated mechanical latch of claim 3 further comprising a gasket abutting the seating portion and enabling sealing of the plunger to the closed end of the mortis. 5. The vacuum actuated mechanical latch of claim 4, further comprising a gasket that abuts the seat and enables the plunger to seal against the closed end of the mortis. 4. The latch of claim 3, wherein the head of the plunger has an inclined guide surface that minimizes friction when the plunger is pressed into the first locking position. 2. A vacuum actuated mechanical latch according to claim 1 wherein the urging means comprises a compression spring. 2. The vacuum actuated mechanical latch of claim 1 wherein said urging means comprises a bellows having a first end attached to said housing and a second end attached to said plunger. A sealable semiconductor wafer container having a vacuum operated mechanical latch, comprising: a. A container having a closed top, sidewalls, an open bottom end, and a hermetically sealable door to seal the open bottom end; b. A plurality of latches for mechanically latching the door to the container, each latch including a housing and a plunger, the housing having a mortise formed inwardly from an outer surface thereof and a vacuum port formed into the mortise from an outer surface of the housing; Wherein the plunger is slidably disposed in the mortis and can also be in a first locking position in which the door is latched in the container and in a second retracted position (open position) in which the door can be separated from the container, and in vacuum And the plunger includes a plurality of latches that can move from the first locking position to the second retracted position when a vacuum is applied to the port. The semiconductor wafer container according to claim 10, wherein the latch further comprises a compression spring, and the plunger has a barrel having a head formed at one end and a seating portion formed at the other end opposite the head. 11. The latch of claim 10, wherein the latch further comprises a bellows, the plunger having a barrel having a head formed at one end and a seating portion formed at the other end opposite the head, wherein the first end of the bellows is attached to the housing. And the second end of the bellows is attached to the plunger. 12. The semiconductor wafer container of claim 11, wherein the barrel further comprises a shoulder inclined longitudinally from the seat toward the head. 12. The semiconductor wafer container of claim 11, further comprising a gasket that abuts the seating portion and allows the plunger to seal against the closed end of the mortis. 12. The semiconductor of claim 11 wherein the head of the plunger further comprises an inclined guide surface that minimizes friction when the plunger is pressed into the first locking position to engage the inner recess of the container. Wafer container. The container of claim 10, wherein the housing is integral with the container.

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