Integrated latch for wafer cassette

Abstract

The wafer container is provided with a latching mechanism for securing the wafer cassette within the container. The latching mechanism is actuated by contact between the inner surface of the pod dome and a horizontal bar provided on the wafer cassette, and contacts the wafer cassette. The latching mechanism includes a dome contact element configured to contact the inner surface of the dome. The latching mechanism is further configured to retract so as not to overlap the horizontal bar when not in contact with the dome. The latching mechanism is integrated into or attached to the door.

Description

[Technical Field]

[0001] More particularly, the present disclosure relates to a latch for securing a wafer cassette within a wafer container by contacting the cassette with a horizontal bar. [Background technology]

[0002] Wafers, such as semiconductor wafers, can be stored in cassettes. The cassettes are placed within a container that includes a dome and a door. To reduce or prevent movement, a cassette hold-down mechanism can be provided on the dome, or one or more cassette hold-down members can be installed between the dome and the cassette. The internal features of the dome and the features on the cassette that can be engaged by the hold-down are not standardized and can vary widely between manufacturers, product lines, product generations, etc. Summary of the Invention

[0003] More particularly, the present disclosure relates to a latch for securing a wafer cassette within a wafer container by contacting the cassette with a horizontal bar.

[0004] By securing the cassette through contact with a standard feature, such as a horizontal bar on the wafer cassette, the latching mechanism can provide a more broadly applicable solution that is less susceptible to product-specific design changes. Furthermore, the latching mechanism according to embodiments automatically extends when the dome and door are mated and retracts when the dome is removed. This facilitates the use of wafer containers that include automated latching mechanisms, eliminating the need to handle and account for potentially different cassette hold-down structures. The latching mechanism also has a profile that does not interfere with the storage of wafers within the wafer cassette. The latching mechanism can also be retrofitted to existing wafer containers by attaching the latching mechanism to the wafer container door.

[0005] In one embodiment, the wafer container includes a dome defining a space configured to accommodate a wafer cassette, the dome including an inner surface and a door opening. The wafer container further includes a door configured to be received in the door opening, the door including a latch mechanism. The latch mechanism includes a dome contact and a cassette contact, and the latch mechanism is configured such that when the inner surface of the dome is in contact with the dome contact, the cassette contact is actuated to contact the wafer cassette, and when the inner surface of the dome is not in contact with the dome contact, the latch does not overlap the wafer cassette.

[0006] In one embodiment, the dome contact is a roller element. In one embodiment, the roller element includes a core made of a first material and an outer portion made of a second material, the second material being relatively softer than the first material.

[0007] In one embodiment, the cassette contacts are configured to contact the wafer cassette at a horizontal bar included in the wafer cassette.

[0008] In one embodiment, the latch mechanism includes a base, a latch arm having a dome contact disposed at a first end thereof and a cassette contact disposed at a second end thereof, and a plurality of links, each link rotatably connected to the base and the latch arm. In one embodiment, the base is coupled to the door. In one embodiment, the wafer container further includes a biasing spring configured to contact the latch arm.

[0009] In one embodiment, the latch mechanism includes a base including a channel configured to receive the dome contact, a latch arm including the cassette contact, and a link rotatably connected to each of the base and the latch arm. The base includes a pin configured to couple with the latch arm. In one embodiment, the latch mechanism further includes a guide roller, the guide roller disposed in the channel.

[0010] In one embodiment, the latch mechanism includes a base defining a channel, a latch arm including a cassette contact, a link having a dome contact attached thereto and rotatably connected to each of the base and the latch arm, and a guide roller attached to the latch arm and configured to move within the channel.

[0011] In one embodiment, the latch mechanism includes a base, a drive arm with a dome contact attached to the drive arm, and a latch arm rotatably connected to the base. The latch arm includes the cassette contact. The drive arm and latch arm are coupled by a cam structure, the cam structure including a protrusion and a groove, configured to drive rotation of the latch arm between an unlatched position and a latched position.

[0012] In one embodiment, a method for securing a wafer cassette within a container includes actuating a latch mechanism by contact between a dome contact of the latch mechanism and an inner surface of the dome so that the cassette contact contacts contact the wafer cassette.

[0013] In one embodiment, the method further includes retracting the cassette contact so that the cassette contact does not overlap the wafer cassette when the dome is removed from contact with the dome contact.

[0014] In one embodiment, the latch mechanism is included in the container door.

[0015] In one embodiment, the cassette contacts contact the wafer cassette at a horizontal bar included in the wafer cassette.

[0016] In one embodiment, the latch mechanism includes a base, a latch arm having a dome contact disposed at a first end thereof and a cassette contact disposed at a second end thereof, and a plurality of links, each link rotatably connected to a respective one of the base and the latch arm.

[0017] In one embodiment, the latch mechanism includes a base including a channel configured to receive the dome contact, a latch arm including the cassette contact, and a link. The link is rotatably connected to each of the base and the latch arm. The base includes a pin configured to couple with the latch arm. In one embodiment, the latch mechanism further includes a guide roller disposed within the channel.

[0018] In one embodiment, the latch mechanism includes a base defining a channel, a latch arm including a cassette contact, a link, and a guide roller. The dome contact is attached to the link, and the link is rotatably connected to each of the base and the latch arm. The guide roller is attached to the latch arm, and the guide roller is configured to move within the channel.

[0019] In one embodiment, the latch mechanism includes a base, a drive arm with a dome contact attached to the drive arm, and a latch arm rotatably connected to the base. The latch arm includes the cassette contact. The drive arm and the latch arm are coupled by a cam structure having a protrusion and a groove. The cam is configured to drive rotation of the latch arm between an unlatched position and a latched position. [Brief explanation of the drawings]

[0020] [Figure 1] 1 illustrates a wafer container according to one embodiment. [Figure 2A] FIG. 1 illustrates a cross-sectional view of a wafer container with a latching mechanism in an unlatched position according to one embodiment. [Figure 2B] 2B is a cross-sectional view of the wafer container of FIG. 2A with the latching mechanism in a latched position according to one embodiment. [Figure 3A] FIG. 1 illustrates a cross-sectional view of a wafer container with a latching mechanism in an unlatched position according to one embodiment. [Figure 3B] 3B is a cross-sectional view of the wafer container of FIG. 3A with the latching mechanism in a latched position according to one embodiment. [Figure 4A]FIG. 1 illustrates a cross-sectional view of a wafer container with a latching mechanism in an unlatched position according to one embodiment. [Figure 4B] 4B is a cross-sectional view of the wafer container of FIG. 4A with the latching mechanism in a latched position according to one embodiment. [Figure 5A] FIG. 1 illustrates a cross-sectional view of a wafer container with a latching mechanism in an unlatched position according to one embodiment. [Figure 5B] FIG. 5B is a cross-sectional view of the wafer container of FIG. 5A with the latching mechanism in a latched position according to one embodiment. [Figure 6A] FIG. 1 illustrates a cross-sectional view of a wafer container with a latching mechanism in an unlatched position according to one embodiment. [Figure 6B] FIG. 6B is a cross-sectional view of the wafer container of FIG. 6A with the latching mechanism in a latched position according to one embodiment. [Figure 7] FIG. 10 is an exploded view of a latch mechanism according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0021] More particularly, the present disclosure relates to a latch for securing a wafer cassette within a wafer container by contacting the cassette with a horizontal bar.

[0022] 1 illustrates a wafer container according to one embodiment. The wafer container 100 includes a dome 102, a door 104, and a wafer cassette 106.

[0023] The dome 102 is configured to define an interior space capable of accommodating a wafer cassette 106. The dome 102 has a door opening 108 configured to receive the door 104 such that the door 104 encloses the interior space of the dome 102.

[0024] The door 104 is configured to be positioned within the door opening 108. The door 104 includes a latch mechanism 110. The latch mechanism 110 is configured such that, when the door 104 and the dome 102 are mated, an inner surface of the dome 102 contacts a portion of the latch mechanism 110, driving the latch mechanism 110 from an unlatched state, in which the latch mechanism 110 does not contact or overlap the wafer cassette 106, to a latched state, in which the latch mechanism 110 contacts the wafer cassette 106 and secures the wafer cassette's position within the wafer container 100. The latch mechanism 110 may contact the wafer cassette 106 at any suitable location such that the wafer cassette 106 may be at least partially secured by such contact. The latch mechanism 110 may contact the wafer cassette 106 via any standard feature, such as a flange, tab, or protrusion, included on the wafer cassette 106. In one embodiment, the latch mechanism 110 may contact the wafer cassette 106 via a horizontal bar 114 included on the wafer cassette 106. The door 104 may further include one or more alignment features 112 configured to contact the wafer cassette 106 when the wafer container 100 is assembled.

[0025] Wafer cassette 106 is configured to store one or more wafers and may include one or more wafer slots 112. A horizontal bar 114 may extend across wafer cassette 106, for example, at the bottom thereof.

[0026] During use, the wafer cassette 106 can be placed on the door 104. Placement of the wafer cassette 106 can be guided by one or more alignment features 112 on the door 104. The dome 102 can then be placed on the door 104 and wafer cassette 106 such that when the door 104 is received within the door opening 108, the wafer cassette 106 is within the interior space of the dome 102. When the dome 102 and door 104 are mated, the inner surface of the dome 102 contacts the latch mechanism 110. Contact between the dome 102 and the latch mechanism 110 activates the latch mechanism, causing the contact surface to contact the wafer cassette 106 and secure the wafer cassette 106. In one embodiment, the contact surface can contact a horizontal bar 114 of the wafer cassette 106. When the pod dome 102 is separated from the pod door 104, the inner surface of the pod dome 102 no longer contacts the latch mechanism 110. The latch mechanism 110 may be configured to return to an unlatched position when the pod dome 102 is no longer in contact with the latch mechanism 110 .

[0027] 2A is a cross-sectional view of a wafer container with a latch mechanism in an unlatched position according to one embodiment. Wafer container 200 includes a dome 202 having an inner surface 204 and a door 206 including a latch mechanism 208. Wafer container 200 further includes a wafer cassette 210 disposed on door 206, with wafer cassette 210 having a horizontal bar 212. In the view shown in FIG. 2A, dome 202 is spaced from door 206, and latch mechanism 208 is in the unlatched position where it does not overlap horizontal bar 212.

[0028] The latch mechanism 208 includes a latch arm 214. The latch arm 214 includes a first end 216 having a contact surface 218. The latch arm 214 further includes a second end 220 having a dome contact retainer 222. The latch arm 214 is provided with a plurality of latch arm link connections 224. A dome contact element 226 is retained within the dome contact retainer 222. The latch mechanism further includes a base 228. The base 228 includes a base link connection 230. A bias spring 232 is provided on the base 228. A plurality of links 234 are provided, and each link 234 is connected to the latch arm link connection 224 and the base link connection 230.

[0029] The latch arm 214 is configured to be movable between an unlatched position, which allows the wafer cassette 210 to be easily placed on or removed from the door 206, and a latched position, in which the latch arm 214 contacts a horizontal bar 212 of the wafer cassette 210 to secure the wafer cassette 210. The latch arm 214 has a first end 216 including a contact surface 218. The contact surface 218 may be integrally formed with the latch arm 214 or may be an additional element attached to the first end 216 of the latch arm 214. The contact surface 218 is configured to contact the horizontal bar 212 to secure the wafer cassette 210. The contact surface 218 may be configured to contact the wafer cassette 210 at any suitable position to secure the wafer cassette 210; one non-limiting example is the horizontal bar 212. The latch arm 214 further includes a second end 220 opposite the first end 216. A dome contact retainer 222 is disposed at the second end 222. The dome contact retainer 222 can include an opening, recess, groove, etc. configured to receive a protrusion of the dome contact element 226, such as an axle of the dome contact element 226, for example.

[0030] An arm link connection 224 is provided along the length of the latch arm 214 to allow the latch arm 214 to be connected to each of the multiple links 234. The arm link connection can be any suitable feature that allows for a rotatable connection. In the non-limiting example shown in FIGS. 2A and 2B , the arm link connection 224 includes an opening in the latch arm 214 and a cylindrical extension that spans the opening. The cylindrical extension is sized such that a clip provided on the end of the link 234 can engage the cylindrical extension, thus providing a rotatable connection between the link 234 and the latch arm 214 at the arm link connection 224.

[0031] The dome contact element 226 is an element configured to contact the inner surface 204 of the dome 202. The dome contact element 226 can be any suitable contact element, such as an element including a cam surface or a fixed curved surface, a roller, or the like. The dome contact element 226 can be, for example, a roller. In one embodiment, the dome contact element 226 includes at least one rounded surface, e.g., circular, oval, or any other shape including a rounded surface. In one embodiment, the dome contact element 226 is circular. In one embodiment, the dome contact element 226 is a single piece. In one embodiment, the dome contact element 226 includes at least two different materials, e.g., a core including a relatively hard and / or more rigid core material and a contact surface made of a relatively soft and / or more flexible contact surface material. In one embodiment, the contact surface can be overmolded onto the core. In one embodiment, the contact surface material can be selected from an elastomer, such as a thermoplastic elastomer, silicone, or the like. The dome contact element 226 may be configured to be housed within or retained by a dome contact retainer 222 that has, for example, an outward protrusion that forms an axle that allows the dome contact element 226 to be retained within the dome contact retainer 222 and to rotate while retained. In one embodiment, the dome contact element 226 is integrally formed with the latch arm 214.

[0032] The base 228 is configured to attach the latch mechanism 208 to the door 206. The base 228 may be attached to the door 206, i.e., formed integrally with the door 206, or may include some portions attached to the door 206 and other portions formed integrally with the door 206. The base 228 may be sized such that the maximum height of the latch mechanism 228 above the surface of the door 206 on which the base 228 is located does not cause the latch mechanism 208 to interfere with wafers placed in the wafer cassette 210. In one embodiment, the base 228 is sized such that the height of the latch mechanism is 0.8 inches (approximately 2 centimeters) or less.

[0033] Base link connections 230 are provided on base 228. The base link connections may be cylindrical bars that extend across an open space in base 228. The cylindrical bars may be sized such that clips on links 234 can engage the cylindrical bars to attach one end of link 234 to one of base link connections 230. The attachment of links 234 to their corresponding base link connections 230 may allow links 234 to rotate, for example, in response to a force that moves latch arm 214 to which link 234 is also connected.

[0034] A biasing spring 232 is provided on the base 228. The biasing spring 232 may be any suitable spring for applying a force to the latch arm 214, such as a spring arm, a leaf spring, or a coil spring. The biasing spring 232 may be a separate element attached to the base 228 or may be integrally formed with the base 228. The biasing spring is configured to contact the latch arm 214. The biasing spring is configured to drive the latch arm 214 into an unlatched state in which the latch arm 214 does not overlap the horizontal bar 212. In the embodiment shown in FIG. 2A , the force applied by the biasing spring 232 drives the latch arm 214 upward. The upward movement of the latch arm 214 is partially translated into the latch arm 214 moving outward to the unlatched state due to the fixed length and rotation of the link 234.

[0035] Links 234 couple latch arms 232 to base 228. Links 234 are rotatable at each connection between latch arms 232 and base 228. In one embodiment, links 234 each include a first clip attached at a first end to one of arm link connections 224 and a second clip attached at an opposite end of link 234 to one of base link connections 230. Each of links 234 has a fixed length. The fixed length and rotatable connection of links 234 controls the movement of latch arms 214 relative to base 228 so that latch arms 214 can move between latched and unlatched positions.

[0036] FIG. 2B is a cross-sectional view of the wafer container of FIG. 2A when the latch mechanism is in a latched position according to one embodiment. In the latched position shown in FIG. 2B, the inner surface 204 of the dome 202 contacts the dome contact element 226. The contact between the inner surface 204 and the dome contact element 226 drives the dome contact element 226 inward. By connecting the dome contact element 226 to the latch arm 214, the latch arm 214 is also driven inward. The inward movement of the latch arm 214 rotates the link 234, which pulls the latch arm 214 downward as it moves inward. This force overcomes the force provided by the biasing spring 232, thus moving the contact surface 218 up and down the horizontal bar 212 of the wafer cassette 210. The contact surface 218 therefore secures the position of the wafer cassette 210 on the door 206. When the dome 202 is removed from the door 206, the biasing spring drives the latch arm 214 downward, causing a rotational movement defined by the link 234, returning the latch arm 214 to an unlatched position where it does not overlap the horizontal bar 212, allowing the wafer cassette 210 to be removed from the door 206 without interference from the latch mechanism 208.

[0037] 3A is a cross-sectional view of a wafer container with a latch mechanism in an unlatched position according to one embodiment. Wafer container 300 includes a dome 302 having an inner surface 304 and a door 306 including a latch mechanism 308. Wafer container 300 further includes a wafer cassette 310 disposed on door 306, with wafer cassette 310 having a horizontal bar 312. In the view shown in FIG. 3A, dome 302 is spaced from door 306 and latch mechanism 308 is in the unlatched position where it does not overlap horizontal bar 312.

[0038] The latch mechanism 308 includes a latch arm 314. The latch arm 314 includes a first end 316 having a contact surface 318. The latch arm 314 further includes a second end 320 having a dome contact retainer 322. The latch arm 314 is provided with a plurality of latch arm link connections 324. A dome contact element 326 is retained within the dome contact retainer 322. The latch mechanism further includes a base 328. The base 328 includes a base link connection 330. A bias spring 332 is provided on the base 328. A plurality of links 334 are provided, each connected to a latch arm link connection 324 and a base link connection 330.

[0039] The latch arm 314 is configured to be movable between an unlatched position, which allows the wafer cassette 310 to be easily placed on or removed from the door 306, and a latched position, in which the latch arm 314 contacts the horizontal bar 312 of the wafer cassette 310 to secure the wafer cassette 310. The latch arm 314 has a first end 316 that includes a contact surface 318. The contact surface 318 may be integrally formed with the latch arm 314 or may be an additional element attached to the first end 316 of the latch arm 314. The contact surface 318 may be configured to contact the wafer cassette 310 at any suitable position to secure the wafer cassette 310. In one embodiment, the contact surface 318 is configured to contact the horizontal bar 312 to secure the wafer cassette 310. The contact surface 318 may include a ramp, inclined surface, step, shoulder, ledge, or any other suitable feature such that the contact surface 318 can effectively retain the horizontal bar 312 despite the latch arm 314 being moved upward as the latch arm 314 is actuated into the latched position. The latch arm 314 further includes a second end 320 opposite the first end 316. A dome contact retainer 322 is disposed at the second end 322. The dome contact retainer may include an opening, recess, groove, etc. configured to receive a protrusion of the dome contact element 326, such as an axle of the dome contact element 326.

[0040] An arm link connection 324 is provided along the length of the latch arm 314 to allow the latch arm 314 to be connected to each of the multiple links 334. The arm link connection can be any suitable feature that allows for a rotatable connection. In the non-limiting example shown in FIGS. 3A and 3B , the arm link connection 324 includes an opening in the latch arm 314 and a cylindrical extension that spans the opening. The cylindrical extension is sized such that a clip provided on the end of the link 334 can engage the cylindrical extension, thus providing a rotatable connection between the link 334 and the latch arm 314 at the arm link connection 324.

[0041] The dome contact element 326 is an element configured to contact the inner surface 304 of the dome 302. The dome contact element 326 can be any suitable contact element, such as an element including a cam surface or a fixed curved surface, a roller, etc. In one embodiment, the dome contact element 326 includes at least one rounded surface, e.g., circular, oval, or any other shape including a rounded surface. In one embodiment, the dome contact element 326 is circular. In one embodiment, the dome contact element 326 is a single piece. In one embodiment, the dome contact element 326 includes at least two different materials, e.g., a core including a relatively hard and / or more rigid core material and a contact surface made of a relatively soft and / or more flexible contact surface material. In one embodiment, the contact surface can be overmolded onto the core. In one embodiment, the contact surface material can be selected from an elastomer, such as a thermoplastic elastomer, silicone, or the like. The dome contact element 326 may be configured to be housed within or held by a dome contact retainer 322, for example, having an outward protrusion that forms an axle that allows the dome contact element 326 to be held within the dome contact retainer 322 and to rotate while held.

[0042] The base 328 is configured to mount the latch mechanism 308 to the door 306. The base 328 may be attached to the door 306, i.e., formed integrally with the door 306, or may include some portions attached to the door 306 and other portions formed integrally with the door 306. The base 328 is sized and configured to provide an open space in which the latch arm 314 can move between the latched and unlatched positions. The base 328 may be sized such that the maximum height of the latch mechanism 328 above the surface of the door 306 on which the base 328 is disposed does not cause the latch mechanism 308 to interfere with wafers placed in the wafer cassette 310. In one embodiment, the base 328 is sized such that the height of the latch mechanism is 0.8 inches (approximately 2 centimeters) or less.

[0043] Base link connections 330 are provided on base 328. The base link connections may be cylindrical bars that extend across an open space in base 328. The cylindrical bars may be sized so that clips on links 334 can engage the cylindrical bars to attach one end of link 334 to one of base link connections 330. The attachment of links 334 to their corresponding base link connections 330 may allow links 334 to rotate, for example, in response to a force that moves latch arm 314 to which link 334 is also connected.

[0044] A biasing spring 332 is provided on the base 328. The biasing spring 332 may be any suitable spring for applying a force to the latch arm 314, such as a spring arm, a leaf spring, or a coil spring. The biasing spring 332 may be a separate element attached to the base 328 or may be integrally formed with the base 328. The biasing spring is configured to contact the latch arm 314. The biasing spring is configured to drive the latch arm 314 into an unlatched state in which the latch arm 314 does not overlap the horizontal bar 312. In the embodiment shown in FIG. 3A , the force applied by the biasing spring 332 drives the latch arm 314 outward into the unlatched state. The biasing spring 332 may be coupled to the latch arm 314 by a coupling mechanism 336 provided on the latch arm 314, such as a tab including a protrusion or recess, a contact surface configured to receive a portion of the biasing spring 332, or another suitable mechanism that allows the biasing spring to act securely on the latch arm 314.

[0045] Links 334 couple the latch arms 314 to the base 328. The links 334 are rotatable at their respective connections to the latch arms 314 and the base 328. In one embodiment, each link 334 includes a first clip attached at a first end to one of the arm link connections 324 and a second clip attached at an opposite end of the link 334 to one of the base link connections 330. Each link 334 has a fixed length. The fixed length and rotatable connection of the links 334 controls the movement of the latch arms 314 relative to the base 328 so that the latch arms 314 can move between latched and unlatched positions.

[0046] FIG. 3B is a cross-sectional view of the wafer container of FIG. 3A when the latch mechanism is in a latched position according to one embodiment. In the latched position shown in FIG. 3B, the inner surface 304 of the dome 302 contacts the dome contact element 326. The contact between the inner surface 304 and the dome contact element 326 drives the dome contact element 326 inward. By connecting the dome contact element 326 to the latch arm 314, the latch arm 314 is also driven inward. The inward movement of the latch arm 314 rotates the link 334, which pulls the latch arm 314 downward as it moves inward. This force overcomes the force provided by the biasing spring 332, thus moving the contact surface 318 onto the horizontal bar 312 of the wafer cassette 310. The contact surface 318 therefore secures the position of the wafer cassette 310 on the door 306. When the dome 302 is removed from the door 306, the biasing spring drives the latch arm 314 upward, causing a rotational movement defined by the link 334, returning the latch arm 314 to an unlatched position where it does not overlap the horizontal bar 312, allowing the wafer cassette 310 to be removed from the door 306 without interference from the latch mechanism 308.

[0047] 4A is a cross-sectional view of a wafer container with a latch mechanism in an unlatched position according to one embodiment. The wafer container 400 includes a dome 402 having an inner surface 404, a door 406 having a latch mechanism 408, and a wafer cassette 410 having a horizontal bar 412. The latch mechanism 408 includes a latch arm 414 having a first end 416 with a contact surface 418. The latch arm 414 further includes a second end 420 having a dome contact retainer 422. A dome contact element 424 is attached to the latch arm 414 at the dome contact retainer 422. The latch arm 414 further includes an arm link attachment portion 426 and an opening 428. The latch mechanism further includes a base 430 including a base link attachment portion 432 and a bias pin 434 including a protrusion 436 and a spring 438. A link 442 is connected to each of the latch arm 414 and the base 430.

[0048] The latch mechanism 408 includes a latch arm 414 including a first end 416 having a contact surface 418. The contact surface 418 is configured to contact the wafer cassette 410 when the latch mechanism is in the latched position. The contact surface 418 can be configured to contact the wafer cassette 410 at any suitable location to secure the wafer cassette 410; one non-limiting example is a horizontal bar 412. The latch mechanism 408 further includes a second end 420 to which a dome contact element 424 is attached. In one embodiment, a dome contact retainer 422 is located at the second end 420. The dome contact element 424 is attached to the latch arm 414 at the dome contact retainer 422, for example. The dome contact element 424 can be any suitable contact element, such as an element including a cam surface or a fixed curved surface, a roller, or the like. In one embodiment, the dome contact element 424 includes at least two different materials, for example, a core including a harder or more rigid core material and a softer or more flexible contact surface. In one embodiment, the contact surface may be overmolded onto the core. In one embodiment, the contact surface material may be selected from one or more elastomers from the list of thermoplastic elastomers, silicones, etc.

[0049] Arm link attachment portion 426 is configured to allow link 442 to be attached to latch arm 414. Arm link attachment portion 426 may be any suitable structure that allows link 442 to be mechanically attached to latch arm 414, such as a cylinder surrounded by an opening that allows a clip included in link 442 to be attached to arm link attachment portion 426. In one embodiment, arm link attachment portion 426 may be a clip or socket configured to receive a portion of link 442. The connection of arm link attachment portion 426 to link 442 may allow link 442 and latch arm 414 to rotate relative to each other.

[0050] Latch arm 414 includes an opening 428. Opening 428 is configured to receive a protrusion 436 included on biasing pin 434. In one embodiment, opening 428 may have rounded or beveled edges, for example, to facilitate insertion of protrusion 436 of biasing pin 434 into opening 428. Opening 428 is formed in latch arm 414 to allow protrusion 436 of biasing pin 434 to apply a force to latch arm 414, for example, to drive latch arm 414 toward an unlatched state when no force is being applied to the latch arm by dome contact element 424.

[0051] Latch mechanism 408 further includes a base 430. Base 430 is mounted to door 406. In one embodiment, base 430 has a maximum height above door 406 of 0.8 inches or less. Base 430 defines a channel 440. Channel 440 is configured to accommodate a base link attachment 432, which can be any suitable structure that allows dome contact element 424 to rotatably connect link 442 to base 430. Base link attachment 432 can be, for example, a cylindrical member having an opening therearound to allow attachment of a clip, a clip or socket configured to receive a portion of link 442, or the like.

[0052] The base 430 further includes a biasing pin 434 configured to return the latch arm 414 to the unlatched position when no other forces are acting on the latch arm 414. The biasing pin 434 includes a protrusion 436 and a spring 438. The protrusion 436 is configured to be received in an opening 428 in the latch arm 414. The protrusion 436 is provided with a spring 438. The spring 438 is configured to allow deflection of the protrusion 436 when other forces are applied, such as when the dome 402 contacts the dome contact element 424, and to provide a force that returns the protrusion 436 to a position where the latch arm 414 is in the unlatched position. The spring 438 may be any suitable spring, such as one or more spring arms. The spring 438 may be a separate spring attached to the base 430 or formed integrally with the base 430. The protrusion 436 may be a separate element from the spring 438 and attached to the spring 438, or may be integrally formed with the spring 438. In one embodiment, the base 430, spring 438, and protrusion 436 are all integrally formed with one another. In an alternative embodiment, the relative positions of the opening 428 and the protrusion 436 can be reversed, with the protrusion 436 extending from the latch arm 414 and the opening 428 attached to the spring 438 or defined in material included along the spring 438. In another alternative embodiment, the spring 438 may alternatively be included in the latch arm 414, with one of the protrusion 436 and the material defining the opening 428 disposed on the spring 438 and the other of the protrusion 436 and the material defining the opening 428 provided in a fixed position on the base 430.

[0053] Link 442 is rotatably attached to latch arm 414 at arm link attachment 426 and to base 430 at base link attachment 432. Link 442 is configured to control movement of latch arm 414 relative to base 430 upon contact between dome 402 and dome contact element 424 and / or upon application of force to latch arm 414 by bias pin 434. Link 442 can be rigid and have a fixed length. The attachments of link 442 to latch arm 414 and base 430 can be at opposite ends of link 442. Link 442 can include any suitable structure for engaging and rotatably attaching to arm link attachment 426 and base link attachment 432, such as a clip, socket, or corresponding engagement mechanism such as a ball joint or cylindrical portion with an adjacent opening.

[0054] 4B is a cross-sectional view of the wafer container of FIG. 4A when the latch mechanism is in the latched position according to one embodiment. When the dome 402 is attached to the door 406, the inner surface 404 contacts the dome contact element 424, driving the dome contact element 424 to move within the channel 440, thereby driving the latch arm 414 inward. The force moving the latch arm 414 overcomes the force exerted by the spring 438 on the protrusion 436, thus moving the protrusion 436 at least partially out of the opening 428 and allowing the latch arm 414 to move. The inward movement of the latch arm 414 is controlled by the link 442, which moves inward and downward so that the contact surface 418 contacts the horizontal bar 412. The contact between the contact surface 418 and the horizontal bar 412 secures the wafer cassette 410 to the door 406. When the dome 402 is removed, the force applied to the protrusion 436 by the spring 438 drives the protrusion 436 back into the opening 428, returning the latch arm 414 to an unlatched position where it does not overlap the horizontal bar 412, allowing the wafer cassette 410 to be removed from the door 406 without interference from the latch mechanism 408.

[0055] 5A is a cross-sectional view of a wafer container with a latch mechanism in an unlatched position according to one embodiment. The wafer container 500 includes a dome 502 including an inner surface 504, a door 506 including a latch mechanism 508, and a wafer cassette 510 including a horizontal bar 512. The latch mechanism 508 includes a latch arm 514 including a first end 516 having a contact surface 518. The contact surface 518 can be configured to contact the wafer cassette 510 at any suitable location to secure the wafer cassette 510; one non-limiting example is the horizontal bar 512. The latch arm 514 further includes a second end 520 having a dome contact retainer 522. A dome contact element 524 and a guide roller 526 can each be attached to the latch arm 514 at the dome contact retainer 522. The latch arm 514 further includes an arm link attachment portion 528 and an opening 530. The latch mechanism further includes a base 532 defining a channel 542. Base 532 may include a base link attachment portion 534 and a biasing pin 536 that includes a protrusion 538 and a spring 540. A link 544 is connected to each of latch arm 514 and base 532.

[0056] The latch mechanism 508 includes a latch arm 514 including a first end 516 having a contact surface 518. The contact surface 518 is configured to contact the wafer cassette 510 when the latch mechanism is in the latched position. The latch mechanism 508 further includes a second end 520 to which a dome contact element 524 is attached. In one embodiment, a dome contact retainer 522 is at the second end 520. The dome contact element 524 is attached to the latch arm 514 at the dome contact retainer 522, for example. The dome contact element 524 can be any suitable contact element, such as an element including a cam surface or a fixed curved surface, a roller, or the like. In one embodiment, the dome contact element 524 includes at least two different materials, for example, a core including a harder or more rigid core material and a softer or more flexible contact surface. In one embodiment, the contact surface can be overmolded onto the core. In one embodiment, the contact surface material can be selected from one or more elastomers from a list of thermoplastic elastomers, silicones, and the like.

[0057] A guide roller 526 is attached to the latch arm 514. The guide roller 526 can help guide the movement of the latch arm 514 from the latched position to the unlatched position. The guide roller 526 can be sized to contact only the door 506 as it moves between the latched and unlatched positions. The guide roller 526 includes at least two different materials, for example, a core including a harder or more rigid core material and a softer or more flexible contact surface. In one embodiment, the contact surface can be overmolded onto the core. In one embodiment, the contact surface material can be selected from one or more elastomers from a list of thermoplastic elastomers, silicones, etc.

[0058] Arm link attachment portion 528 is configured to allow link 544 to be attached to latch arm 514. Arm link attachment portion 528 can be any suitable structure that allows link 544 to be mechanically attached to latch arm 514, such as a cylinder surrounded by an opening that allows a clip included in link 544 to be attached to arm link attachment portion 528. In one embodiment, arm link attachment portion 528 can be a clip or socket configured to receive a portion of link 544. The connection of arm link attachment portion 528 to link 544 can allow link 544 and latch arm 514 to rotate relative to each other.

[0059] Latch arm 514 includes an opening 530. Opening 530 is configured to receive a protrusion 538 included on biasing pin 536. In one embodiment, opening 530 may have rounded or beveled edges, for example, to facilitate insertion of protrusion 538 of biasing pin 536 into opening 530. Opening 530 is formed in latch arm 514 to allow protrusion 538 of biasing pin 536 to apply a force to latch arm 514, for example, to drive latch arm 514 toward an unlatched state when no force is being applied to the latch arm by dome contact element 524.

[0060] The latch mechanism 508 further includes a base 532. The base 532 is mounted to the door 506. In one embodiment, the base 530 has a maximum height above the door 506 of 0.8 inches or less. The base 532 defines a channel 542. The channel 542 is configured to allow the dome contact element 524 to move through the channel 542 in a plane with the door 506. The channel 542 can be sized such that the dome contact element 524 contacts at most one surface inside the channel 542 as the dome contact element 524 moves through the channel. The channel 542 can be sized such that the guide roller 526 contacts only one surface inside the channel 542 as the guide roller 526 moves through the channel. The guide roller 526 and the channel 542 can be configured such that the guide roller 526 rolls along the door 506 and / or the base 532 without rubbing against any other surfaces mounted in the channel 542. Base 532 includes base link attachment portion 534, which may be any suitable structure that allows for rotatable connection of link 544 to base 532. Base link attachment portion 534 may be, for example, a cylindrical member having an opening therearound that allows for attachment of a clip, a clip or socket configured to receive a portion of link 544, or the like.

[0061] The base 532 further includes a biasing pin 536 configured to return the latch arm 514 to the unlatched position when no other forces are acting on the latch arm 514. The biasing pin 536 includes a protrusion 538 and a spring 540. The protrusion 538 is configured to be received in an opening 530 in the latch arm 514. The protrusion 538 is provided with a spring 540. The spring 540 is configured to allow deflection of the protrusion 538 when other forces are applied, such as when the dome 502 contacts the dome contact element 524, and to provide a force that returns the protrusion 538 to a position where the latch arm 514 is in the unlatched position. The spring 540 may be any suitable spring, such as one or more spring arms. The spring 540 may be a separate spring attached to the base 532 or formed integrally with the base 532. The protrusion 538 may be a separate element from the spring 540 and attached to the spring 540, or may be integrally formed with the spring 540. In one embodiment, the base 532, spring 540, and protrusion 538 are all integrally formed with one another. In an alternative embodiment, the relative positions of the opening 530 and the protrusion 538 can be reversed, with the protrusion 538 extending from the latch arm 514 and the opening 530 attached to the spring 540 or defined in material included along the spring 540. In another alternative embodiment, the spring 540 may alternatively be included in the latch arm 514, with one of the protrusion 538 and the material defining the opening 530 disposed on the spring 540 and the other of the protrusion 538 and the material defining the opening 530 provided in a fixed position on the base 532.

[0062] Link 544 is rotatably attached to latch arm 514 at arm link attachment 528 and to base 532 at base link attachment 534. Link 544 is configured to control movement of latch arm 514 relative to base 532 upon contact between dome 502 and dome contact element 524 and / or upon application of force to latch arm 514 by bias pin 536. Link 544 can be rigid and have a fixed length. The attachments of link 544 to latch arm 514 and base 532 can be at opposite ends of link 544. Link 544 can include any suitable structure for engaging and rotatably attaching to arm link attachment 528 and base link attachment 534, such as a clip, socket, or corresponding engagement mechanism such as a ball-and-socket joint, a cylindrical portion with adjacent openings, or the like.

[0063] 5B is a cross-sectional view of the wafer container of FIG. 5A with the latch mechanism in the latched position according to one embodiment. When the dome 502 is attached to the door 506, the inner surface 504 contacts the contact dome contact element 524, driving the contact dome contact element 524 and the guide dome contact element 526 to move within the channel 542, thereby driving the latch arm 514 inward. The contact dome contact element 524 can roll along the upper surface of the channel 542, and the guide dome contact element 526 can roll along the lower surface of the channel 542. In one embodiment, the contact dome contact element 524 does not contact the lower surface of the channel 542, and the guide dome contact element 526 does not contact the upper surface of the channel 542. This can reduce or eliminate particle generation due to the sliding of the dome contact elements 524, 526 along the surface of the channel 542. The force moving the latch arm 514 overcomes the force exerted by the spring 540 on the protrusion 538, thus moving the protrusion 538 at least partially out of the opening 530 and allowing movement of the latch arm 514. The inward movement of the latch arm 514 is controlled by the link 544, which moves inward and downward so that the contact surface 518 contacts the horizontal bar 512. The contact between the contact surface 518 and the horizontal bar 512 secures the wafer cassette 510 to the door 506. When the dome 502 is removed, the force exerted on the protrusion 538 by the spring 540 drives the protrusion 538 back into the opening 530, returning the latch arm 514 to an unlatched position where it does not overlap the horizontal bar 512, allowing the wafer cassette 510 to be removed from the door 506 without interference from the latch mechanism 508.

[0064] 6A is a cross-sectional view of a wafer container with a latching mechanism in an unlatched position according to one embodiment. The wafer container 600 includes a dome 602 having an inner surface 604, a door 606 including a latching mechanism 608, and a wafer cassette 610 including a horizontal bar 612. The latching mechanism 608 includes a link 614. A dome contact element 616 is attached to the link 614. The link 614 is also attached to a latch arm 618. The latch arm 618 includes a contact surface 620 at a first end 622, a link attachment portion 624 and a second end 626, and a guide roller 628. The link 614 is also attached to a base 630. The base 630 defines a channel 632.

[0065] Link 614 is coupled to base 630 at a first attachment point and to latch arm 618 at a second attachment point. The attachments are configured to allow link 614 to rotate relative to base 630 and latch arm 618 to rotate relative to link 614. Link 614 includes a dome contact element 616. In one embodiment, dome contact element 616 is fixed directly to link 614, e.g., integrally formed with link 614. In one embodiment, dome contact element 616 is a separate element attached to link 614, e.g., a roller attached to link 614 via a retainer. Dome contact element 616 can be any suitable contact element, such as an element including a cam surface or a fixed curved surface, a roller, etc. In one embodiment, dome contact element 616 has a relatively rigid core and a relatively flexible contact surface. In one embodiment, link 614 is triangular in shape, with link 614 attached to latch arm 618 at a first point of the triangle, link 614 attached to base 630 at a second point of the triangle, and dome contact element 616 attached at a third point of the triangle. The shape of link 614 may be such that the mass distribution of link 614 causes the attachment 614 to latch arm 618 to be at the relatively lowest point of link 614 when link 614 is at rest with no other forces acting on link 614.

[0066] A latch arm 618 is attached to the link 614. The latch arm 618 includes a contact surface 620 at a first end 622. The contact surface 620 can be configured to contact the wafer cassette 610 at any suitable location to secure the wafer cassette 610; one non-limiting example is a horizontal bar 612. A link attachment 624 is provided at a second end 626 opposite the first end 622. The link attachment can be any suitable mechanism for attaching the latch arm 618 to the link 614 so that the latch arm 618 can rotate relative to the link 614. A guide roller 628 is provided along the latch arm 618. The latch arm 618 can be located at a point closer to the first end 622 than the second end 626 so that the mass of the side of the guide roller 628 toward the second end 626 exceeds the mass of the side of the guide roller 628 toward the first end 622. The distribution of the mass of the latch arm 618 relative to the guide roller 628 can be such that, in the absence of other forces acting on the link 614 or the latch arm 618, gravity tends to pull the second end 626 downward. Additionally, in one embodiment, a spring is configured to allow the sides of the guide roller 628 to flex and return the sides of the guide roller 628 to a position where the latch arm 618 is in the unlatched position when other forces are applied, such as when the dome 604 contacts the dome contact element 616.

[0067] The base 630 is provided in a fixed position on the door 606. The base 630 can be integrally formed with the door 606 or can be a separate element secured to the door 606 by any suitable means, such as a mechanical connection, adhesive, welding, etc. In one embodiment, the base 630 is welded to the door 606. The base 630 can have a height of 0.8 inches or less from the surface of the door 606. The base 630 can define a channel 632 configured to allow the guide roller 628 to move within the channel 632. In one embodiment, the guide roller 628 and the channel 632 are sized such that the guide roller 628 contacts only one surface within the channel 632 and can roll along said surface without rubbing against any other surfaces provided within the channel 632. Base 630 can be configured to allow link 614 to be rotatably attached to the base, for example, by providing a clip, a cylindrical area surrounded by an opening, or any other suitable mechanism that corresponds to the attachment mechanism provided on link 614.

[0068] 6B is a cross-sectional view of the wafer container of FIG. 6A when the latch mechanism is in the latched position according to one embodiment. When the inner surface 604 of the dome 602 contacts the dome contact element 616, the link 614 is actuated to rotate about its connection to the base 630 and drive the latch arm 618 inward toward the latched position. The rotation of the link 614 also lifts the link attachment portion 624, raising the second end 626 and lowering the first end 622 as the latch arm 618 rotates about the guide roller 628. Thus, the contact surface 620 is forced inward and downward to contact the horizontal bar 612, thus retaining the wafer cassette 610 within the wafer container 600. When the dome 602 is removed and the dome contact element 616 is no longer in contact with the inner surface 604, the weight of the latch arm 618 and link 614 causes the link mounting portion 624 and the mounting portion of the link 614 to drop, causing the rotation of the link 614 to retract the latch arm 618 into an unlatched position where it does not overlap with the horizontal bar 612, and allowing the latch arm 618 to rotate about the guide roller 628 to lift the first end 622.

[0069] FIG. 7 is an exploded view of a latch mechanism according to one embodiment. Latch mechanism 700 can be used as a latch mechanism in a wafer container, such as wafer container 100 described above and shown in FIG. 1 . Latch mechanism 700 includes a base 702. Base 702 comprises a base body 704, a hinge pin 706, a biasing spring 708, and a biasing pin 710. Latch mechanism 700 further includes a latch tab 712. Latch tab 712 includes a contact surface 714, a hinge opening 716, and a cam opening 718. Latch mechanism 700 also includes a latch arm 720. Latch arm 720 includes a cam protrusion 722, a biasing opening 724, and a roller retainer 726. A dome contact element 728, including a core 730, an axle protrusion 732, and a contact surface 734, can be retained within roller retainer 726.

[0070] The base 702 is configured to couple to a wafer container door. In one embodiment, the base 702 may be integrally formed with the wafer container door. In one embodiment, the base 702 is coupled to the wafer container door by welding. The base 702 includes a base body 704. The base body 704 is configured to define a channel that can accommodate the latch arm 720. The base 702 further includes a hinge pin 706. The hinge pin 706 is a pin that extends from the base body 704 and is sized to be received in a hinge opening 716 in the latch tab 712. In one embodiment, the hinge pin 706 can be replaced with an opening, the hinge opening 716 can be replaced with a pin, and the arrangement of the hinge pin 706 and hinge opening 716 shown in FIG. 7 can be reversed. The hinge pin 706 and hinge opening 716 are configured to couple the latch tab 712 to the base 702, allowing the latch tab to rotate about the axis of the hinge pin 706 between an unlatched position and a latched position. The base 702 includes a biasing spring 708 and a biasing pin 710. The biasing pin 710 is disposed along or coupled to the biasing spring 708 such that the biasing spring provides a force to position the biasing pin 710. The biasing pin 710 is a protrusion configured to be received in a biasing opening 724 formed in the latch arm 720. The biasing spring 708 can be configured to allow the biasing pin 710 to deflect when a force is applied to the latch arm, for example, by the dome contacting a dome contact element 728. The spring 708 can then return the biasing pin 710 to a position that causes the biasing pin 710 to move the latch arm 720 to the unlatched position when no other force is applied to the latch arm 720 .

[0071] The latch tab 712 is configured to extend or retract to respectively retain or release a horizontal bar of a wafer cassette. The latch tab 712 includes a contact surface 714 configured to contact the wafer cassette at any suitable location capable of securing the wafer cassette when the latch tab 712 is rotated to the latched position. In one embodiment, the contact surface 714 is configured to contact a horizontal bar included in the wafer cassette. The latch tab 712 includes a hinge opening 716 configured to receive the hinge pin 706, allowing the latch tab to rotate relative to the base 702. The latch tab 712 further includes a cam opening 718. The cam opening 718 is sized and shaped such that a cam protrusion 722 of the latch arm 720 can be received therein and such that the cam protrusion 722 can slide within the cam opening 718 in at least one direction coplanar with the latch tab 712.

[0072] The latch arm 720 is configured to drive the latch tab 712 to a latched or unlatched position. The latch arm includes a cam protrusion 722 at one end of the latch arm 720. The cam protrusion 722 is configured to be received within the cam opening 718 such that the cam protrusion 722 slides within the cam opening 718 to extend or retract the latch tab 712. A latch arm bias opening 724 is disposed along the length of the latch arm 720. The latch arm bias opening 724 is configured to receive the bias pin 710. The latch arm bias opening 724 is positioned such that when the bias pin 710 is received in the latch arm bias opening 724 and the spring 708 is in a neutral position, the latch arm 720 is in the unlatched position. The latch arm bias opening 724 may include a rounded or beveled edge. The latch arm 720 may include a dome contact element 728. The dome contact element 728 may be any suitable element for contacting the dome of a wafer container such that contact between the dome and the dome contact element 728 can actuate the latch arm 720. In the embodiment shown in FIG. 7, the dome contact element 728 is a roller held within a roller holder 726. In the embodiment shown in FIG. 7, the roller used as the dome contact element 728 includes a core 730, an axle protrusion 732, and a contact surface 734. The core 730 may be made of a relatively rigid material, while a relatively flexible material is used for the contact surface 734. In one embodiment, the contact surface 734 is overmolded onto the core 730. The axle protrusion 732 may be received within the roller holder 726 to couple the dome contact element 728 to the latch arm 720.

[0073] When a wafer container including latch mechanism 700 is assembled, contact between the wafer container dome and dome contact element 726 drives latch arm 720 inward relative to the wafer container. The force applied to dome contact element 726 overcomes the force applied to bias pin 710 by bias spring 708, causing the bias pin to exit bias opening 724, allowing latch arm 720 to move inward. As latch arm 720 moves inward, cam projection 722 moves within cam opening 718, driving latch tab 712 to rotate about hinge pin 706 into a latched position where contact surface 714 overlaps the horizontal bar of the wafer cassette. Thus, contact surface 714 can retain a wafer cassette within a wafer container including latch mechanism 700. When the dome is removed from the wafer container door containing the latch mechanism 700, the dome no longer applies force to the dome contact element and the biasing pin 710 is driven by the biasing spring 708 into the biasing opening 724, moving the latch arm 720 outward and the cam projection 722 within the cam opening 718, allowing the latch tab 712 to retract to an unlatched position where the latch tab does not overlap the horizontal bar of the wafer cassette.

[0074] Aspects It is understood that any of the embodiments 1 to 11 can be combined with any of the embodiments 12 to 20.

[0075] Aspect 1 1. A wafer container comprising: a dome defining a space configured to receive a wafer cassette, the dome including an interior surface and a door opening; a door configured to be received in the door opening, the door including a latch mechanism; Equipped with The latch mechanism includes a dome contact and a cassette contact, and the latch mechanism is configured such that when the inner surface of the dome contacts the dome contact, the cassette contact is driven to contact the wafer cassette, and when the inner surface of the dome does not contact the dome contact, the latch does not overlap the wafer cassette.

[0076] Aspect 2 2. The wafer container of embodiment 1, wherein the dome contact is a roller element.

[0077] Aspect 3 3. The wafer container of embodiment 2, wherein the roller element comprises a core made of a first material and an outer portion made of a second material, the second material being relatively softer than the first material. Aspect 4 A wafer container according to any one of aspects 1 to 3, wherein the cassette contact is configured to contact the wafer cassette at a horizontal bar included in the wafer cassette.

[0078] Aspect 5 The latch mechanism A base and a latch arm, the dome contact disposed at a first end of the latch arm and the cassette contact disposed at a second end of the latch arm; a plurality of links rotatably connected to each of the base and the latch arm; 5. The wafer container according to any one of aspects 1 to 4, comprising:

[0079] Aspect 6 6. The wafer container of embodiment 5, wherein the base is coupled to the door.

[0080] Aspect 7 7. The wafer container of embodiment 5 or 6, further comprising a biasing spring configured to contact the latch arm.

[0081] Aspect 8 The latch mechanism a base including a channel configured to receive the dome contact; a latch arm including a cassette contact; a link rotatably connected to each of the base and the latch arm; Including, 5. The wafer container of any one of embodiments 1-4, wherein the base includes a pin configured to couple with the latch arm.

[0082] Aspect 9 9. The wafer container of embodiment 8, wherein the latching mechanism further comprises a guide roller, the guide roller being disposed within the channel.

[0083] Aspect 10 The latch mechanism a base defining a channel; a latch arm including a cassette contact; a link, the dome contact attached to the link, the link rotatably connected to each of the base and the latch arm; a guide roller attached to the latch arm, the guide roller configured to move within the channel; 5. The wafer container according to any one of aspects 1 to 4, comprising:

[0084] Aspect 11 The latch mechanism A base and a drive arm having a dome contact attached thereto; a latch arm rotatably connected to the base, the latch arm including a cassette contact, the drive arm and the latch arm being coupled by a cam structure, the cam structure including a protrusion and a groove, configured to drive rotation of the latch arm between an unlatched position and a latched position; 2. The wafer container of embodiment 1, comprising:

[0085] Aspect 12 1. A method for securing a wafer cassette within a container, comprising: actuating a latch mechanism by contact between a dome contact of said latch mechanism and an inner surface of a dome such that the cassette contact contacts contact the wafer cassette.

[0086] Aspect 13 13. The method of embodiment 12, further comprising retracting the cassette contact such that the cassette contact does not overlap the wafer cassette when the dome is removed from contact with the dome contact.

[0087] Aspect 14 14. The method of any one of embodiments 12 to 13, wherein the latch mechanism is included in the container door.

[0088] Aspect 15 A method according to any one of aspects 12 to 14, wherein the cassette contacts contact the wafer cassette at a horizontal bar included in the wafer cassette.

[0089] Aspect 16 The latch mechanism A base and a latch arm, the dome contact disposed at a first end of the latch arm and the cassette contact disposed at a second end of the latch arm; a plurality of links rotatably connected to each of the base and the latch arm; 16. The method according to any one of aspects 12 to 15, comprising:

[0090] Aspect 17 The latch mechanism a base including a channel configured to receive the dome contact; a latch arm including a cassette contact; a link rotatably connected to each of the base and the latch arm; 16. The method of any of embodiments 12-15, comprising:

[0091] Aspect 18 18. The method of embodiment 17, wherein the latching mechanism further comprises a guide roller disposed within the channel.

[0092] Aspect 19 The latch mechanism a base defining a channel; a latch arm including a cassette contact; a link having a dome contact attached thereto, the link rotatably connected to each of the base and the latch arm; a guide roller attached to the latch arm, the guide roller configured to move within the channel; 16. The method according to any one of aspects 12 to 15, comprising:

[0093] Aspect 20 The latch mechanism A base and a drive arm to which the dome contact is attached; a latch arm rotatably connected to the base, the latch arm including a cassette contact, the drive arm and the latch arm being coupled by a cam structure, the cam structure including a protrusion and a groove, the cam configured to drive rotation of the latch arm between an unlatched position and a latched position; 16. The method according to any one of aspects 12 to 15, comprising:

[0094] The examples disclosed in this application should be considered in all respects as illustrative and not restrictive. The scope of the present invention is indicated by the appended claims, rather than the foregoing description, and all changes that come within the meaning and range of equivalence of the claims are intended to be embraced therein.

Claims

1. 1. A wafer container comprising: a dome defining a space configured to receive a wafer cassette, the dome including an interior surface and a door opening; a door configured to be received in the door opening, the door including a latch mechanism; Equipped with the latch mechanism includes a dome contact and a cassette contact, and the latch mechanism is configured such that when the inner surface of the dome is in contact with the dome contact, the cassette contact is driven to contact the wafer cassette, and when the inner surface of the dome is not in contact with the dome contact, the latch does not overlap the wafer cassette. Wafer container.

2. The wafer container of claim 1 , wherein the dome contact is a roller element.

3. The latch mechanism is A base and a latch arm, the dome contact disposed at a first end of the latch arm and the cassette contact disposed at a second end of the latch arm; a plurality of links, each link rotatably connected to the base and each of the latch arms; The wafer container of claim 1 , comprising:

4. The wafer container of claim 3 further comprising a biasing spring configured to contact the latch arm.

5. The latch mechanism is a base including a channel configured to receive the dome contact; a latch arm including the cassette contact; a link rotatably connected to each of the base and the latch arm; Including, the base including a pin configured to couple with the latch arm; The wafer container of claim 1 .

6. The wafer container of claim 5 , wherein the latch mechanism further comprises a guide roller, the guide roller being disposed within the channel.

7. The latch mechanism is a base defining a channel; a latch arm including the cassette contact; a link, the dome contact attached to the link, the link rotatably connected to each of the base and the latch arm; a guide roller attached to the latch arm and configured to move within the channel; The wafer container of claim 1 , comprising:

8. The latch mechanism is A base and a drive arm to which the dome contact is attached; a latch arm rotatably connected to the base, the latch arm including the cassette contact, the drive arm and the latch arm being coupled by a cam structure, the cam structure including a protrusion and a groove and configured to drive rotation of the latch arm between an unlatched position and a latched position; The wafer container of claim 1 , comprising:

9. 1. A method for securing a wafer cassette within a container, comprising: actuating a latch mechanism by contact between a dome contact of the latch mechanism and an inner surface of a dome such that a cassette contact contacts the wafer cassette.

10. 10. The method of claim 9, further comprising retracting the cassette contact so that the cassette contact does not overlap the wafer cassette when the dome is removed from contact with the dome contact.

11. The latch mechanism is A base and a latch arm, the dome contact disposed at a first end of the latch arm and the cassette contact disposed at a second end of the latch arm; a plurality of links, each link rotatably connected to the base and each of the latch arms; 10. The method of claim 9, comprising:

12. The latch mechanism is a base including a channel configured to receive the dome contact; a latch arm including the cassette contact; a link rotatably connected to each of the base and the latch arm; Including, the base including a pin configured to couple with the latch arm; 10. The method of claim 9.

13. The method of claim 12 , wherein the latch mechanism further comprises a guide roller disposed within the channel.

14. The latch mechanism is a base defining a channel; a latch arm including the cassette contact; a link, the dome contact attached to the link, the link rotatably connected to each of the base and the latch arm; a guide roller attached to the latch arm and configured to move within the channel; The method of claim 8, comprising:

15. The latch mechanism is A base and a drive arm to which the dome contact is attached; a latch arm rotatably connected to the base, the latch arm including the cassette contact, the drive arm and the latch arm being coupled by a cam structure, the cam structure including a protrusion and a groove, the cam configured to drive rotation of the latch arm between an unlatched position and a latched position; The method of claim 8, comprising:

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